transforming-growth-factor-beta and Obesity

Follistatin (FST) is a glycoprotein which main role is antagonizing activity of transforming growth factor β superfamily members. Folistatin-related proteins such as follistatin-like 3 (FSTL3) also reveal these properties. The exact function of them has still not been established, but it can be bound to the pathogenesis of metabolic disorders. So far, there were performed a few studies about their role in type 2 diabetes, obesity or gestational diabetes and even less in type 1 diabetes. The outcomes are contradictory and do not allow to draw exact conclusions. In this article we summarize the available information about connections between follistatin, as well as follistatin-like 3, and metabolic disorders. We also emphasize the strong need of performing further research to explain their exact role, especially in the pathogenesis of diabetes and obesity.

Topics: Diabetes Mellitus, Type 2; Follistatin; Humans; Obesity; Transforming Growth Factor beta

Previously, we showed that knockout mice homozygous for deficiency of the mercapturic acid pathway (MAP) transporter protein, RLIP (RLIP

Topics: Acetylcysteine; Adipokines; Animals; Carcinogenesis; Carcinogens; Carrier Proteins; Clathrin; Cytokines; Epidermal Growth Factor; GTPase-Activating Proteins; Humans; Infant; Insulins; Male; Mice; Neoplasms; Obesity; Oxidative Stress; Peptide Hormones; Transforming Growth Factor beta; Tumor Suppressor Protein p53

Aging is broadly defined as the functional decline that occurs in all body systems. The accumulation of senescent cells is considered a hallmark of aging and thought to contribute to the aging pathologies. Transforming growth factor-β (TGF-β) is a pleiotropic cytokine that regulates a myriad of cellular processes and has important roles in embryonic development, physiological tissue homeostasis, and various pathological conditions. TGF-β exerts potent growth inhibitory activities in various cell types, and multiple growth regulatory mechanisms have reportedly been linked to the phenotypes of cellular senescence and stem cell aging in previous studies. In addition, accumulated evidence has indicated a multifaceted association between TGF-β signaling and aging-associated disorders, including Alzheimer's disease, muscle atrophy, and obesity. The findings regarding these diseases suggest that the impairment of TGF-β signaling in certain cell types and the upregulation of TGF-β ligands contribute to cell degeneration, tissue fibrosis, inflammation, decreased regeneration capacity, and metabolic malfunction. While the biological roles of TGF-β depend highly on cell types and cellular contexts, aging-associated changes are an important additional context which warrants further investigation to better understand the involvement in various diseases and develop therapeutic options. The present review summarizes the relationships between TGF-β signaling and cellular senescence, stem cell aging, and aging-related diseases.

Topics: Aging; Alzheimer Disease; Cell Proliferation; Cellular Senescence; Fibrosis; Hematopoietic Stem Cells; Homeostasis; Inflammation; Ligands; Mesenchymal Stem Cells; Muscular Atrophy; Obesity; Signal Transduction; Stem Cells; Transforming Growth Factor beta

Accumulation of dysfunctional white adipose tissues increases risks for cardiometabolic diseases in obesity. In addition to white, brown or brite adipose tissues are also present in adult humans and increasing their amount may be protective. Therefore, understanding factors regulating the amount and function of each adipose depot is crucial for developing therapeutic targets for obesity and its associated metabolic diseases. The transforming growth factor beta (TGFβ) superfamily, which consists of TGFβ, BMPs, GDFs, and activins, controls multiple aspects of adipose biology. This review focuses on the recent development in understanding the role of TGFβ superfamily in the regulation of white, brite and brown adipocyte differentiation, adipose tissue fibrosis, and adipocyte metabolic and endocrine functions. TGFβ family and their antagonists are produced locally within adipose tissues and their expression levels are altered in obesity. We also discuss their potential contribution to adipose tissue dysfunction in obesity.

Topics: Adipocytes; Adipose Tissue; Animals; Cell Differentiation; Fibrosis; Humans; Obesity; Transforming Growth Factor beta

Obesity is a major risk factor for the development of diabetes, insulin resistance, dyslipidemia, cardiovascular disease and other related metabolic conditions. Obesity develops from perturbations in overall cellular bioenergetics when energy intake chronically exceeds total energy expenditure. Lifestyle interventions based on reducing total energy uptake and increasing activities including exercise have proved ineffective in the prevention and treatment of obesity because of poor adherence to such interventions for an extended period of time. Brown adipose tissue (BAT) has an extraordinary metabolic capacity to burn excess stored energy and holds great promise in combating obesity and related diseases. This unique ability to nullify the effects of extra energy intake of these specialized tissues has provided attractive perspectives for the therapeutic potential of BAT in humans. Browning of white adipose tissue by promoting the expression and activity of key mitochondrial uncoupling protein 1 (UCP1) represents an exciting new strategy to combat obesity via enhanced energy dissipation. Members of the transforming growth factor-beta (TGF-β) superfamily including myostatin and follistatin have recently been demonstrated to play a key role in regulating white adipose browning both in in-vitro and in-vivo animal models and thereby present attractive avenues for exploring the therapeutic potential for the treatment of obesity and related metabolic diseases.

Topics: Adipose Tissue, Brown; Adipose Tissue, White; Animals; Energy Metabolism; Fibronectins; Follistatin; Gene Expression Regulation; Humans; MAP Kinase Kinase Kinases; Models, Animal; Multigene Family; Myostatin; Obesity; Signal Transduction; Transforming Growth Factor beta

To provide a perspective by investigating the potential cross-talk between the adipose tissue and the kidney during obesity.. It is well established that excessive caloric intake contributes to organ injury. The associated increased adiposity initiates a cascade of cellular events that leads to progressive obesity-associated diseases such as kidney disease. Recent evidence has indicated that adipose tissue produces bioactive substances that contribute to obesity-related kidney disease, altering the renal function and structure. In parallel, proinflammatory processes within the adipose tissue can also lead to pathophysiological changes in the kidney during the obese state.. Despite considerable efforts to better characterize the pathophysiology of obesity-related metabolic disease, there are still a lack of efficient therapeutic strategies. New strategies focused on regulating adipose function with respect to AMP-activated protein kinase activation, NADPH oxidase function, and TGF-β may contribute to reducing adipose inflammation that may also provide renoprotection.

Topics: Adipose Tissue; AMP-Activated Protein Kinases; Cytokines; Fibrosis; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Inflammation; Insulin Resistance; Kidney; NADPH Oxidases; Nephritis; Obesity; Receptors, G-Protein-Coupled; Transforming Growth Factor beta

Heart failure (HF) and atrial fibrillation (AF) are two growing epidemics associated with significant morbidity and mortality. They often coexist due to common risk factors and shared pathophysiological mechanisms. Patients presenting with both HF and AF have a worse prognosis and present a particular therapeutic challenge to clinicians. This review aims to appraise the common pathophysiological background, as well as the prognostic and therapeutic implications of coexistent HF and AF.

Topics: Anticoagulants; Atrial Fibrillation; Calcium; Extracellular Matrix; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Heart Failure; Hemodynamics; Humans; Obesity; Renin-Angiotensin System; Transforming Growth Factor beta

GDF-15 (also MIC-1, NAG-1, PLAB, PTGFB) is a member of the TGF-β superfamily, which is widely distributed in mammalian tissues and has been shown to play multiple roles in various pathologies, including inflammation, cancer, cardiovascular diseases, and obesity. GDF-15 serum levels are a highly reliable predictor of disease progression. Both the anti-tumorigenic potential of GDF-15 and its capacity to promote metastasis have been documented for a large variety of cancers, yet its opposing functions, which are typical for members of the TGF-β superfamily, have only partly been resolved on the molecular level. Knowledge on physiological functions in the non-diseased organism is scarce. In the nervous system GDF-15 knockout analyses have revealed that GDF-15 is essential for the postnatal maintenance of various neuron populations. When applied exogenously GDF-15 is a powerful factor for promoting survival of developing and lesioned neurons in vitro and in vivo. Receptor activation by GDF-15 has only been partially resolved.

Topics: Animals; Cardiovascular Diseases; Gene Expression Regulation; Growth Differentiation Factor 15; Humans; Inflammation; Mice; Neoplasms; Obesity; Signal Transduction; Tissue Distribution; Transforming Growth Factor beta

Rising obesity epidemic makes the better understanding of transcription factor networks regulating adipogenesis very challenging. Adipogenesis begins with the commitment of pluripotent mesenchymal stem cells to the adipocyte lineage, followed by terminal differentiation of preadipocytes to mature adipocytes. Among the molecules that influence the decision of progenitor cells to become adipocytes are members of transforming growth factor-beta superfamily and particularly bone morphogenetic proteins. Transforming growth factor-beta and bone morphogenetic proteins exert their biological functions mainly through their downstream molecules, the Smads. Here, we review the role(s) of transforming growth factor-beta/bone morphogenetic protein signalling pathway in adipocyte differentiation. Unravelling the precise mechanism of each molecule/pathway is necessary for developing suitable inhibitors or mimetic agents in order to treat obesity and improve insulin resistance. Current research efforts aim at discovering drugs that reduce fat mass or change the phenotype of adipose tissue into a more thermogenic one.

Topics: Adipogenesis; Animals; Anti-Obesity Agents; Biomimetics; Bone Morphogenetic Proteins; Cell Differentiation; Drug Discovery; Humans; Mesenchymal Stem Cells; Obesity; Signal Transduction; Smad Proteins; Transcriptional Activation; Transforming Growth Factor beta

Obesity develops when energy intake exceeds energy expenditure. Although most current obesity therapies are focused on reducing calorific intake, recent data suggest that increasing cellular energy expenditure (bioenergetics) may be an attractive alternative approach. This is especially true for adaptive thermogenesis - the physiological process whereby energy is dissipated in mitochondria of brown fat and skeletal muscle in the form of heat in response to external stimuli. There have been significant recent advances in identifying the factors that control the development and function of these tissues, and in techniques to measure brown fat in human adults. In this article, we integrate these developments in relation to the classical understandings of cellular bioenergetics to explore the potential for developing novel anti-obesity therapies that target cellular energy expenditure.

Topics: Adenosine Triphosphate; Adipose Tissue, Brown; Cell Lineage; Energy Metabolism; Humans; Ion Channels; Mitochondria; Mitochondrial Proteins; Obesity; Thermogenesis; Transforming Growth Factor beta; Uncoupling Protein 1

The review highlights recent findings regarding the functions of mitochondria in adipocytes, providing an understanding of their central roles in regulating substrate metabolism, energy expenditure, disposal of reactive oxygen species (ROS), and in the pathophysiology of obesity and insulin resistance, as well as roles in the mechanisms that affect adipogenesis and mature adipocyte function.. Nutrient excess leads to mitochondrial dysfunction, which in turn leads to obesity-related pathologies, in part due to the harmful effects of ROS. The recent recognition of 'ectopic' brown adipose in humans suggests that this tissue may play an underappreciated role in the control of energy expenditure. Transcription factors, PGC-1alpha and PRDM16, which regulate brown adipogenesis, and members of the TGF-beta superfamily that modulate this process may be important new targets for antiobesity drugs.. Mitochondria play central roles in ATP production, energy expenditure, and disposal of ROS. Excessive energy substrates lead to mitochondrial dysfunction with consequential effects on lipid and glucose metabolism. Adipocytes help to maintain the appropriate balance between energy storage and expenditure and maintaining this balance requires normal mitochondrial function. Many adipokines, including members of the TGF-beta superfamily, and transcriptional coactivators, PGC-1alpha and PRDM16, are important regulators of this process.

Topics: Adipogenesis; Adipokines; Adipose Tissue; Animals; DNA-Binding Proteins; Energy Metabolism; Glucose; Heat-Shock Proteins; Humans; Insulin Resistance; Ion Channels; Lipid Metabolism; Mice; Mitochondrial Diseases; Mitochondrial Proteins; Obesity; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Reactive Oxygen Species; Transcription Factors; Transforming Growth Factor beta; Uncoupling Protein 1

Wound-healing complications following body contouring for massive weight loss patients are significant, with rates exceeding 40 percent. To better understand aberrant healing in this population, the authors have performed a comparative analysis of the wound milieu literature for patient populations with similar complication rates.. PubMed and Ovid databases were reviewed from January of 1985 to January of 2009 for key terms, including wound healing, obesity, cancer, burn, transplant, and body contouring. Serum and wound levels of multiple factors, including matrix metalloproteinases (MMPs) and cytokines, were assessed.. Complication rates in body contouring surgery range from 31 to 66 percent. Sixty-five studies were reviewed, and wound-healing complication rates were identified for cancer (45.8 percent), burn (30.4 percent), posttransplant (36 percent), and obese (43 percent) populations. In these groups, matrix metalloproteinases and tissue inhibitors of metalloproteinase (TIMPs) help regulate wound repair. Matrix metalloproteinase levels were elevated in cancer (4-fold increase in MMP-2), burn (20- to 30-fold increase in MMP-9), transplant (1.4-fold increase in MMP-2), and obese/chronic (79-fold increase) populations. TIMPs were increased in cancer (1.9-fold increase in TIMP-2) and burn (1.4-fold increase in TIMP-1) patients but decreased in chronic wound (55-fold decrease in TIMP-1) populations. Alterations to these regulatory proteins lead to prolonged matrix degradation, up-regulation of inflammatory mediators, and decreased growth factors, delaying the wound-healing process.. Complications after body contouring surgery are likely multifactorial; however, molecular imbalances to the massive weight loss wound milieu may contribute to poor surgical outcomes. Examining wound regulatory proteins including transforming growth factor-beta, vascular endothelial growth factor, and matrix metalloproteinases could aid in understanding the healing difficulties observed clinically.

Topics: Bariatric Surgery; Biomarkers; Burns; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Neoplasms; Obesity; Organ Transplantation; Plastic Surgery Procedures; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Weight Loss; Wound Healing

It was previously believed that obesity and osteoporosis were two unrelated diseases, but recent studies have shown that both diseases share several common genetic and environmental factors. Body fat mass, a component of body weight, is one of the most important indices of obesity, and a substantial body of evidence indicates that fat mass may have beneficial effects on bone. Contrasting studies, however, suggest that excessive fat mass may not protect against osteoporosis or osteoporotic fracture. Differences in experimental design, sample structure, and even the selection of covariates may account for some of these inconsistent or contradictory results. Despite the lack of a clear consensus regarding the impact of effects of fat on bone, a number of mechanistic explanations have been proposed to support the observed epidemiologic and physiologic associations between fat and bone. The common precursor stem cell that leads to the differentiation of both adipocytes and osteoblasts, as well the secretion of adipocyte-derived hormones that affect bone development, may partially explain these associations. Based on our current state of knowledge, it is unclear whether fat has beneficial effects on bone. We anticipate that this will be an active and fruitful focus of research in the coming years.

Topics: 11-beta-Hydroxysteroid Dehydrogenases; Adipocytes; Adiponectin; Adipose Tissue; Amyloid; Aromatase; Bone Density; Cell Differentiation; Female; Humans; Insulin; Insulin-Like Growth Factor II; Interleukin-6; Islet Amyloid Polypeptide; Leptin; Male; Obesity; Osteoblasts; Osteoporosis; Peptide Fragments; PPAR gamma; Resistin; Transforming Growth Factor beta; Wnt Proteins

Peroxisome proliferator-activated receptors (PPAR) and liver X receptors (LXR) regulate a plethora of biologic processes and key metabolic and physiologic events. Deregulation of their transcription and activity is commonly associated with dyslipidemic disorders, diabetes, cancer, and cardiovascular disease. This review addresses recent advances in our understanding of the molecular mechanisms regulating transcription of these nuclear receptors. The heterogeneity of factors regulating their transcription and activity suggests intricate regulatory networks that determine their tissue expression pattern and their responses to pharmacologic agents. Understanding such mechanisms will facilitate unraveling their protective effects in disease as well as the design of effective targeted therapies.

Topics: Adipose Tissue; Atherosclerosis; CCAAT-Enhancer-Binding Proteins; DNA-Binding Proteins; Down-Regulation; Forkhead Transcription Factors; GATA Transcription Factors; Humans; Liver X Receptors; Obesity; Orphan Nuclear Receptors; Oxidative Stress; Peroxisome Proliferator-Activated Receptors; Receptors, Cytoplasmic and Nuclear; Signal Transduction; Sirtuins; Smad Proteins; Transcription, Genetic; Transforming Growth Factor beta; Up-Regulation; Wnt Proteins

Diabetic nephropathy characterized by proteinuria and sclerosis is the leading cause of renal failure, but its mechanisms are not well understood. Zucker Obese (ZO) rat model of obesity, insulin resistance, and hypertension has been used to study nephropathy. We hypothesize that chronically elevated intrarenal angiotensin II (ANG II) down-regulates nephrin, a key slit-pore protein and up-regulates fibrogenic molecule transforming growth factor (TGFbeta1) and thus result in progression of nephropathy in type 2 diabetes. Untreated or angiotensin converting enzyme (ACE) inhibitor, captopril, treated ZO and control Lean (ZL) rats were used to measure intrarenal levels of ANG II, glomerular nephrin, TGFbeta1, collagen and fibronectin with age using radioimmunoassay, RT-PCR and immunoblot techniques. Progression of nephropathy was established by measuring proteinuria and sclerosis. ZO rats developed obesity, hyperglycemia, hyperinsulinimia, increase in intrarenal ANG II and proteinuria. Expression of glomerular nephrin decreased while expression of TGFbeta1 and matrix components increased in ZO rats. Captopril treatment prevented increase in intrarenal ANG II, and reversed expression of nephrin, TGFbeta1, collagen and fibronectin. We conclude that in this model of type 2 diabetic nephropathy, chronically elevated intrarenal ANG II causes proteinuria via decrease in nephrin and glomerulosclerosis via TGFbeta1 mediated increase in matrix component.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Animals, Genetically Modified; Blood Pressure; Chromatography; Collagen; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Glucose; Hyperglycemia; Immunoblotting; Insulin; Insulin Resistance; Kidney; Male; Models, Statistical; Obesity; Proteinuria; Radioimmunoassay; Rats; Rats, Zucker; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

Transforming growth factor beta-1 is involved in local signaling for a variety of human diseases including renal diseases, cardiac hypertrophy and fibrosis in heart failure, hepatic fibrosis, and pulmonary fibrosis. Elevated levels of circulating transforming growth factor beta-1 result in organ fibrosis in animal models. In humans smoking, hypertension, diabetes and obesity appear to result in elevated circulating levels. This paper outlines a hypothesis that elevated circulating levels of transforming growth factor beta-1 are part of the molecular link between several entities that have epidemiologic ties including hypertension, diabetes, smoking and obesity on one hand and diseases resulting in organ fibrosis on the other including renal disease and cardiac fibrosis and hypertrophy in heart failure. Additionally, it is suggested that elevated levels are not simply a marker of a similar mechanism of disease production but that elevated levels of circulating transforming growth factor beta-1 lead to disease production and to the synergy of risk factors seen in production of human fibrotic diseases.

Topics: Animals; Diabetes Mellitus; Fibrosis; Humans; Hypertension; Models, Animal; Obesity; Signal Transduction; Smoking; Transforming Growth Factor beta; Transforming Growth Factor beta1

Drugs designed against targets in presumably simple linear signaling pathways found to be associated with disease are often less effective than predicted. One reason for this is the overly simplistic view of the molecular mechanisms underlying common human diseases. This viewpoint is a consequence of biological reductionism, brought about by the need to form a basic understanding of the fundamental attributes of biological systems and by limitations in the set of tools available for analysis of biological systems. However, complex biological systems are best modeled as highly modular, fluid systems exhibiting a plasticity that allows them to adapt to a vast array of conditions. Historically, this viewpoint has long represented the ideal, but the tools needed to examine and describe this complexity were often lacking. Here we argue that the tools of biological science now allow for a more network-oriented view of biological systems and for explaining the underlying causes of disease, as well as the best ways to target disease. Ultimately, this will help to ensure that the right drug is administered to the right patient at the right time. Focusing on well-studied signaling pathways, refining the definition of disease, and identifying disease subtypes, we demonstrate a more holistic approach to elucidating common human diseases, with the potential to revolutionize treatment of these diseases.

Topics: Animals; Crosses, Genetic; Drug Design; Drug Evaluation, Preclinical; Gene Expression Profiling; Gene Expression Regulation; Genotype; Humans; Liver; Mice; Mice, Inbred Strains; Models, Biological; Obesity; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

Expanded adipose tissue mass increases the risk for many clinical conditions including diabetes, hypertension, coronary atherosclerotic heart disease, and some forms of cancer. Therefore, it is imperative that we understand the mechanisms by which fat pads expand. The enlargement of fat cells during the development of obesity has been previously hypothesized to be a triggering factor for the proliferation of new fat cells. There is now a preponderance of evidence that adipose tissue is a source of growth factors such as IGF-I, IGF binding proteins, TNF alpha, angiotensin II, and MCSF that are capable of stimulating proliferation. The relative importance of these autocrine/paracrine factors in the normal control of preadipocyte proliferation is unknown. In addition, the proliferative response of preadipocytes to the paracrine milieu is undoubtedly modulated by neural inputs to fat tissue and/or serum factors. Together, these multiple regulatory controls orchestrate overall and region-specific adipose tissue cellularity responses associated with the development of hyperplastic obesity. Both in vivo and in vitro studies are needed to understand the complex, interacting physiological mechanisms by which growth of this important organ is regulated.

Topics: Adipocytes; Adipose Tissue; Angiotensin II; Cell Division; Humans; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor I; Macrophage Colony-Stimulating Factor; Obesity; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

In this chapter, we summarize our studies on plasminogen activator inhibitor 1 (PAI-1), tissue factor, and transforming growth factor beta (TGF-beta) expression in obesity, using genetically obese mice as a model. These studies emphasize the key role played by the adipocyte, a cell whose numbers, size, and metabolic activity are grossly altered in obesity/NIDDM. They also implicate multiple cytokines, hormones, and growth factors in the abnormal expression of these and perhaps other hemostatic genes by adipocytes in obesity/NIDDM. These studies demonstrate that tumor necrosis factor alpha (TNF-alpha) plays a central role in the expression of hemostatic genes in this disorder.

Topics: Adipocytes; Animals; Diabetes Mellitus; Diabetes Mellitus, Type 2; Gene Expression Regulation; Hemostasis; Humans; Mice; Mice, Obese; Obesity; Plasminogen Activator Inhibitor 1; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Topics: Adipose Tissue; Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Gene Expression; Hemostasis; Humans; Mice; Obesity; Plasminogen Activator Inhibitor 1; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vascular Diseases

Topics: Adipocytes; Animals; Cardiovascular Diseases; Fatty Acids, Nonesterified; Gene Expression Regulation; Humans; Insulin; Obesity; Plasminogen Activator Inhibitor 1; RNA, Messenger; Serine Proteinase Inhibitors; Thromboplastin; Thrombosis; Transforming Growth Factor beta; Triglycerides; Tumor Necrosis Factor-alpha

Plasminogen activator inhibitor-1 is elevated in obesity and may be a risk factor for obesity/NIDDM related cardiovascular disease. In spite of this, little is known about the tissue and cellular origin of elevated PAI-1 in obesity or of the mediators and molecular mechanisms that regulate it. We have begun to systematically address these issues using genetically obese (ob/ob, db/db) mice. Plasma PAI-1 levels were 5-fold higher in obese mice compared to their lean counterparts. Subsequent RT-PCR and in situ hybridization studies suggest that the increased plasma PAI-1 originates primarily from the adipocyte in response to chronically elevated levels of tumor necrosis factor-alpha (TNF-alpha), insulin, and transforming growth factor-beta (TGF-beta). Thus, the signals and mechanisms that lead to elevated plasma PAI-1 observed in obesity are complex, and appear to involve interactions between multiple mediators and the adipose tissue itself.

Topics: Animals; Diabetes Mellitus; Diabetes Mellitus, Type 2; Humans; Mice; Mice, Obese; Models, Genetic; Obesity; Plasminogen Activator Inhibitor 1; Risk Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Late eating has been linked to obesity risk. It is unclear whether this is caused by changes in hunger and appetite, energy expenditure, or both, and whether molecular pathways in adipose tissues are involved. Therefore, we conducted a randomized, controlled, crossover trial (ClinicalTrials.gov NCT02298790) to determine the effects of late versus early eating while rigorously controlling for nutrient intake, physical activity, sleep, and light exposure. Late eating increased hunger (p < 0.0001) and altered appetite-regulating hormones, increasing waketime and 24-h ghrelin:leptin ratio (p < 0.0001 and p = 0.006, respectively). Furthermore, late eating decreased waketime energy expenditure (p = 0.002) and 24-h core body temperature (p = 0.019). Adipose tissue gene expression analyses showed that late eating altered pathways involved in lipid metabolism, e.g., p38 MAPK signaling, TGF-β signaling, modulation of receptor tyrosine kinases, and autophagy, in a direction consistent with decreased lipolysis/increased adipogenesis. These findings show converging mechanisms by which late eating may result in positive energy balance and increased obesity risk.

Topics: Adult; Appetite; Eating; Energy Intake; Energy Metabolism; Ghrelin; Humans; Hunger; Leptin; Metabolic Networks and Pathways; Obesity; Overweight; p38 Mitogen-Activated Protein Kinases; Transforming Growth Factor beta; Tyrosine

Breast cancer-related lymphedema (BCRL) is a treatment-related inflammatory complication in breast cancer survivors (BCSs). This study was aimed to evaluate the effect of synbiotic supplementation on serum concentrations of IL-10, TGF-β, VEGF, adiponectin, and edema volume among overweight or obese BCSs with lymphedema following a low-calorie diet (LCD).. In a randomized double-blind, controlled clinical trial, 88 obese and overweight BCSs women were randomized to synbiotic supplement (. There were no significant differences among participants in the baseline, except for IL-10 and adiponectin. Post-intervention, no significant differences were observed regarding the anti-inflammatory markers, including IL-10, VEGF, adiponectin, and TGF-β between the groups. After 10 weeks of intervention edema volume significantly decreased in the synbiotic group; additionally, anthropometric measurements (body weight, BMI, body fat percent, and WC) decreased in both groups significantly (. Synbiotic supplementation coupled with an LCD in a 10-week intervention had beneficial effects on increasing the serum TGF-β, IL-10, and adiponectin levels in women with BCRL. It also reduced arm lymphedema volume. Therefore, synbiotic supplementation can be effective in improving health status in BCRL patients.

Topics: Adiponectin; Anti-Inflammatory Agents; Biomarkers; Breast Neoplasms; Caloric Restriction; Cancer Survivors; Double-Blind Method; Edema; Female; Humans; Interleukin-10; Lymphedema; Obesity; Overweight; Synbiotics; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

To examine the effects of common treatments for polycystic ovary syndrome (PCOS) on a panel of hormones (reproductive/metabolic).. Secondary analysis of blood from a randomized controlled trial of three 16-week preconception interventions designed to improve PCOS-related abnormalities: continuous oral contraceptive pills (OCPs, N = 34 subjects), intensive lifestyle modification (Lifestyle, N = 31), or a combination of both (Combined, N = 29).. Post-treatment levels of activin A and B, inhibin B, and follistatin (FST), as well as Insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 2 (IGFBP-2), glucagon, glucagon-like peptide 1 (GLP-1) and 2, and oxyntomodulin were compared to baseline, and the change from baseline in these parameters were correlated with outcomes.. Oral contraceptive pill use was associated with a significant suppression in activin A, inhibin A, and anti-mullerian hormone (AMH), but a significant increase in FST. IGF-1, IGFBP-2, glucagon, and GLP-2 levels were significantly decreased. Oxyntomodulin was profoundly suppressed by OCPs (ratio of geometric means: 0.09, 95% confidence interval [CI]: 0.05, 0.18, P < 0.001). None of the analytes were significantly affected by Lifestyle, whereas the effects of Combined were similar to OCPs alone, although attenuated. Oxyntomodulin was significantly positively associated with the change in total ovarian volume (rs = 0.27; 95% CI: 0.03, 0.48; P = 0.03) and insulin sensitivity index (rs = 0.48; 95% CI: 0.27, 0.64; P < 0.001), and it was inversely correlated with change in area under the curve (AUC) glucose [rs = -0.38; 95% CI: -0.57, -0.16; P = 0.001]. None of the hormonal changes were associated with live birth, only Activin A was associated with ovulation (risk ratio per 1 ng/mL increase in change in Activin A: 6.0 [2.2, 16.2]; P < 0.001).. In women with PCOS, OCPs (and not Lifestyle) affect a wide variety of reproductive/metabolic hormones, but their treatment response does not correlate with live birth.

Topics: Adolescent; Adult; Behavior Therapy; Combined Modality Therapy; Contraceptives, Oral; Female; Hormones; Humans; Incretins; Life Style; Obesity; Polycystic Ovary Syndrome; Retrospective Studies; Transforming Growth Factor beta; Treatment Outcome; United States; Young Adult

In view of the known vasodilatory effects of glucagon-like peptide-1 and exenatide, we investigated the effects of exenatide on vasoactive factors. We analysed blood samples and mononuclear cells (MNCs) from a previous study, collected after a single dose and 12 weeks of exenatide or placebo treatment in a series of 24 patients with type 2 diabetes mellitus. After exenatide treatment, plasma concentrations of atrial natriuretic peptide, cyclic guanyl monophosphate (cGMP) and cyclic adenyl monophosphate increased significantly at 12 weeks. Plasma cGMP and adenylate cyclase expression in MNCs increased significantly after a single dose. Angiotensinogen concentration fell significantly 2 hours after a single dose and at 12 weeks, while renin and angiotensin II levels fell significantly only after a single dose and not after 12 weeks of treatment. Exenatide also suppressed the plasma concentration of transforming growth factor-β and the expression of P311 in MNCs at 12 weeks. Thus, exenatide induces an increase in a series of vasodilators, while suppressing the renin-angiotensin system. These changes may contribute to the overall vasodilatory effect of exenatide.

Topics: Adenylyl Cyclases; Angiotensinogen; Anti-Obesity Agents; Antihypertensive Agents; Atrial Natriuretic Factor; Blood Pressure; Cyclic AMP; Cyclic GMP; Diabetes Mellitus, Type 2; Exenatide; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Leukocytes, Mononuclear; Nerve Tissue Proteins; Obesity; Oncogene Proteins; Peptides; Renin-Angiotensin System; Reproducibility of Results; Single-Blind Method; Transforming Growth Factor beta; Venoms

The objective of the present study was to investigate the effect of vitamin A supplementation on serum Th17 (IL-6, IL-17, IFNγ) and Treg (TGF-β, IL-10) related cytokines in obese and non-obese women.. In a randomized double blind placebo controlled design, 56 obese women were randomly assigned to receive either an oral dose of 25,000 IU retinyl palmitate or placebo per day for 4 months. Twenty eight ages matched non-obese women were also received vitamin A. At the study entry, anthropometric variables were measured and serum Th17 and Treg related cytokine profile were determined at baseline and 4 months after intervention.. Significantly higher baseline concentrations of IL-6 were observed in obese compared with non-obese women (P < 0.05). However, the initial concentrations of other cytokines were not significantly different between groups. The mean concentrations of IL-17 and TGF-β were significantly decreased after vitamin A supplementation in non-obese and obese women respectively. Positive relationships between IL-17 and IL-10 (r = 0.42, P < 0.001), TGF-β and IL-17 (r = 0.35, P < 0.001) and between IL-10 and IFN-γ (r = 0.41, P = 0.002) in total participants were also observed.. The results of the present study showed for the first time that vitamin A supplementation reduces serum concentrations of IL-17 and TGF-β in reproductive age women. Further studies are needed to explore the possible underlying mechanisms.

Topics: Adult; Analysis of Variance; Cytokines; Dietary Supplements; Double-Blind Method; Female; Humans; Interferon-gamma; Interleukin-10; Interleukin-17; Interleukin-6; Obesity; Statistics, Nonparametric; T-Lymphocytes, Regulatory; Th17 Cells; Transforming Growth Factor beta; Vitamin A; Vitamins

Adipose tissue is a dynamic endocrine organ that regulates whole-body energy homeostasis through the secretion of signalling molecules. Recent reports suggest that secreted microRNAs (miRNAs) may function as biologically active molecules for intercellular communication. This study aims to identify obesity-related circulating miRNA that could be secreted from adipocytes and to explore its possible role in the pathogenesis of metabolic diseases.. Real-time RT-PCR was used to evaluate the circulating level of miR-130b in mouse models of obesity as well as in humans. Luciferase assay and immunoblotting were used to verify the miRNA target. The effect of miR-130b on mouse peroxisome proliferator-activated receptor γ coactivator-1α was also investigated by electrogene transfer.. The circulating level of miR-130b was elevated in mouse models of obesity as well as in obese Chinese individuals. More interestingly, the circulating level of miR-130b was positively correlated with BMI. Moreover, circulating miR-130b was a better predictor of the metabolic syndrome than was triacylglycerol level. Mechanistically, adipocytes secreted miR-130b during adipogenesis. TGF-β, which is proportionately increased with obesity, stimulated miR-130b secretion from adipocytes. Furthermore, miR-130b was able to target muscle cells and reduce the expression of its direct target gene, PGC-1α (also known as PPARGC1A), which plays a key role in lipid oxidation in muscle.. Circulating miR-130b reflects the degree of obesity and could serve as a potential biomarker for hypertriacylglycerolaemia and metabolic syndrome. Circulating miR-130b could function as a metabolic mediator for adipose-muscle crosstalk and might be involved in the pathogenesis of obesity-associated metabolic diseases.

Topics: 3T3-L1 Cells; Adipose Tissue; Animals; Humans; Male; Mice; MicroRNAs; Muscle, Skeletal; Obesity; Overweight; Transforming Growth Factor beta

Extracellular matrix proteins are associated with metabolically healthy adipose tissue and regulate inflammation, fibrosis, angiogenesis, and subsequent metabolic deterioration. In this study, we demonstrated that transforming growth factor-beta (TGFBI), an extracellular matrix (ECM) component, plays an important role in adipose metabolism and browning during high-fat diet-induced obesity. TGFBI KO mice were resistant to adipose tissue hypertrophy, liver steatosis, and insulin resistance. Furthermore, adipose tissue from TGFBI KO mice contained a large population of CD11b

Topics: Adipocytes; Adipose Tissue; Adipose Tissue, White; Animals; Diet, High-Fat; Insulin Resistance; Mice; Mice, Inbred C57BL; Obesity; Signal Transduction; Transforming Growth Factor beta

Obesity is linked to cardiometabolic diseases, however non-obese individuals are also at risk for type 2 diabetes (T2D) and cardiovascular disease (CVD). White adipose tissue (WAT) is known to play a role in both T2D and CVD, but the contribution of WAT inflammatory status especially in non-obese patients with cardiometabolic diseases is less understood. Therefore, we aimed to find associations between WAT inflammatory status and cardiometabolic diseases in non-obese individuals.. In a population-based cohort containing non-obese healthy (n = 17), T2D (n = 16), CVD (n = 18), T2D + CVD (n = 19) individuals, seventeen different cytokines were measured in WAT and in circulation. In addition, 13-color flow cytometry profiling was employed to phenotype the immune cells. Human T cell line (Jurkat T cells) was stimulated by rCCL18, and conditioned media (CM) was added to the in vitro cultures of human adipocytes. Lipolysis was measured by glycerol release. Blocking antibodies against IFN-γ and TGF-β were used in vitro to prove a role for these cytokines in CCL18-T-cell-adipocyte lipolysis regulation axis.. In CVD, T2D and CVD + T2D groups, CCL18 and CD4. We suggest that in T2D and CVD, increased production of CCL18 recruits and activates CD4

Topics: Adipose Tissue; Adipose Tissue, White; Cardiovascular Diseases; CD4-Positive T-Lymphocytes; Chemokines, CC; Cytokines; Diabetes Mellitus, Type 2; Glycerol; Humans; Obesity; T-Lymphocytes; Transforming Growth Factor beta

The evidence shows that obesity is associated with chronic inflammation in obese subjects. Polyphenols are a complex group of plant secondary metabolites that may play a role in reducing the risk of obesity and obesity-related diseases. Given the scarcity of evidence on the association between inflammatory markers and dietary polyphenols intake in overweight/obese Iranian women, the current study aims to investigate this link.. The present cross-sectional study was conducted on 391 overweight and obese Iranian women aged 18-48 years (body mass index (BMI) ≥ 25 kg/m. The findings revealed a significant negative association between flavonoids intake and MCP-1 (P = 0.024), lignans intake and MCP-1 (P = 0.017), and Gal-3 (P = 0.032). These significant associations were observed between other polyphenols intake and IL_1β (P = 0.014). There was also a significant positive association between other polyphenol intake and TGF-β (P = 0.008) and between phenolic acid intake and TGF-β (P = 0.014).. Our findings suggest that a high polyphenol intake may help individuals to reduce systemic inflammation. Further large studies involving participants of different ages and genders are highly warranted.

Topics: Biomarkers; Body Mass Index; Cholesterol; Cross-Sectional Studies; Female; Humans; Inflammation; Iran; Male; Obesity; Overweight; Polyphenols; Transforming Growth Factor beta

Renovascular hypertension (RHV) is the cause of high blood pressure due to left renal ischemia, and obesity and hypertension cause an inflammatory response. This work analyzed the inflammatory and tissue repair profile in renal, hepatic, and cardiac tissues in an animal model of RVH associated with a high-fat diet and caloric restriction. The expressions of RORγ-t, IL-17, T-bet, and TNF-α decreased and IFN-γ increased in the right kidney. In relation to the left kidney, caloric restriction decreased the expression of IFN-γ. In the liver, caloric restriction decreased RORγ-t, IL-17, and T-bet. Hypertension associated with obesity decreased the expression of IFN-γ, while caloric restriction increased. In the right kidney, hypertension and obesity, associated or not with caloric restriction, increased the area of collagen fibers. In the heart and liver, caloric restriction reduced the area of collagen fibers. Caloric restriction increased vascular endothelial growth factor, reduced levels of growth transformation factor-β1 (TGF-β), and increased collagen I in the left kidney. Hypertension/obesity, submitted or not having caloric restriction, increased TGF-β in liver. The results suggest that caloric restriction has beneficial effects in lowering blood pressure and regulating tissue proinflammatory cytokines. However, there was no change in the structure and composition of tissue repair markers.

Topics: Animals; Caloric Restriction; Collagen; Hypertension, Renovascular; Inflammation; Interleukin-17; Obesity; Rats; Rats, Wistar; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Obesity-induced inflamed visceral adipose tissue (VAT) secretes pro-inflammatory cytokines thereby promoting systemic inflammation and insulin resistance which further exacerbate obesity-associated nonalcoholic fatty liver disease (NAFLD). Transforming growth factor (TGF)-β /Smad3 signaling plays a crucial role in the inflammatory events within the VAT. Here, we investigate whether SP-1154, a novel synthetic verbenone derivative, can inhibit TGF-β/Smad3 signaling thereby exhibiting a therapeutic effect against obesity-induced inflamed VAT and subsequent NAFLD in high-fat diet-induced mice.. NAFLD was induced by a high-fat diet (60% fat) for 20 weeks using the male C57BL/6 mice. SP-1154 (50 mg/kg) was orally given daily for 20 weeks. In vivo VAT- and systemic inflammation were measured by using. SP-1154 inhibited TGF-β/Smad3 signaling pathway and remarkably suppressed high-fat diet-induced VAT inflammation and its related systemic inflammation. Furthermore, SP-1154 significantly improved insulin sensitivity with glucose homeostasis and reduced hepatic steatosis. SP-1154 significantly improves VAT inflammation and obesity-related NAFLD.. Our novel findings support the potential use of SP-1154 as a therapeutic drug for obesity and its related NAFLD by targeting the inflamed VAT.

Topics: Animals; Diet, High-Fat; Glucose Tolerance Test; Inflammation; Insulin Resistance; Intra-Abdominal Fat; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Positron-Emission Tomography; Smad3 Protein; Transforming Growth Factor beta

Transforming growth factor beta (TGF-β) signaling in hepatocytes promotes steatosis and body weight gain. However, processes that TGF-β signaling in hepatocytes promote pathological body weight gain in nonalcoholic fatty liver disease (NAFLD) are incompletely understood. Obesity and NAFLD were induced by 16 weeks of feeding a high-fat diet (HFD) in hepatocyte-specific TGF-β receptor II-deficient (Tgfbr2

Topics: Adipose Tissue, White; Animals; Hepatocytes; Mice; MicroRNAs; Non-alcoholic Fatty Liver Disease; Obesity; Receptor, Transforming Growth Factor-beta Type II; Transforming Growth Factor beta; Weight Gain

Obesity causes renal changes (ORC), characterized by defective renal autophagy, lipogenesis, enhanced macrophage infiltration and apoptosis. We hypothesize that Dasatinib, a tyrosine kinase inhibitor, may ameliorate changes associated with obesity. We the mice with either Obesogenic diet (OD) or a standard basal diet. After 12 weeks, the mice received either vehicle or Dasatinib 4 mg/kg/d for an additional four weeks. We examined serum creatinine, urea, lipid profile and renal cortical mRNA expression for lipogenesis marker SREBP1, inflammatory macrophage marker iNOS and fibrosis markers; TGFβ and PDGFA genes; immunohistochemical (IHC) staining for CD68; inflammatory macrophage marker and ASMA; fibrosis marker, LC3 and SQSTM1/P62; autophagy markers and western blotting (WB) for caspase-3; and, as an apoptosis marker, LC3II/I and SQSTM1/P62 in addition to staining for H&E, PAS, Sirius red and histopathological scoring. Dasatinib attenuated renal cortical mRNA expression for SREBP1, iNOS, PDGFA and TGFβ and IHC staining for CD68, ASMA and SQSTM1/P62 and WB for caspase-3 and SQSTM1/P62, while elevating LC3 expression. Moreover, Dasatinib ameliorated ORC; glomerulosclerosis, glomerular expansion, tubular dilatation, vacuolation and casts; inflammatory cellular infiltration; and fibrosis. Dasatinib is a promising therapy for ORC by correcting autophagy impairment, attenuating lipogenesis, apoptosis and macrophage infiltration by inducing antifibrotic activity.

Topics: Animals; Apoptosis; Autophagy; Caspase 3; Dasatinib; Fibrosis; Kidney; Macrophages; Mice; Mice, Obese; Obesity; RNA, Messenger; Sequestosome-1 Protein; Transforming Growth Factor beta

Obesity is a common comorbid condition in adult asthmatics and known as a feature of asthma severity. However, the molecular mechanism under obesity-induced inflammation has not yet been fully understood.. Considering the essential role of hydrophobic surfactant protein B (SP-B) in lung function, SP-B was targeted to examine its involvement in the development of obesity-induced airway inflammation in asthmatics.. The aim was to examine an alteration in circulating SP-B according to obesity in adult asthmatics, 129 asthmatics were enrolled and classified into 3 groups (obese, overweight and normal-weight groups) according to body mass index (BMI). Circulating SP-B levels were determined by enzyme-linked immunosorbent assay. Four single nucleotide polymorphisms of SFTPB gene were genotyped. Serum ceramide levels were measured by liquid chromatography-tandem mass spectrometry.. Significantly lower serum SP-B levels were noted in the obese group than in the overweight or normal-weight group (p = .002). The serum SP-B level was significantly correlated with serum levels of C18:0 ceramide and transforming growth factor beta 1 as well as BMI (r = -0.200; r = -0.215; r = -0.332, p < .050 for all). An inverse correlation was noted between serum SP-B and fractional exhaled nitric oxide levels in female asthmatics (r = -0.287, p = .009). Genetic predisposition of the SFTPB gene at 9306 A>G to the obese and overweight groups was noted.. Obesity altered ceramide metabolism leading to pulmonary surfactant dysfunction and impaired resolution of airway inflammation, finally contributing to the phenotypes of obese asthmatics.

Topics: Asthma; Ceramides; Female; Humans; Inflammation; Obesity; Overweight; Surface-Active Agents; Transforming Growth Factor beta

Adipose tissue contains progenitor cells that contribute to beneficial tissue expansion when needed by de novo adipocyte formation (classical white or beige fat cells with thermogenic potential). However, in chronic obesity, they can exhibit an activated pro-fibrotic, extracellular matrix (ECM)-depositing phenotype that highly aggravates obesity-related adipose tissue dysfunction.. Given that progenitors' fibrotic activation and fat cell browning appear to be antagonistic cell fates, we have examined the anti-fibrotic potential of pro-browning agents in an obesogenic condition.. In obese mice fed a high fat diet, thermoneutral housing, which induces brown fat cell dormancy, increases the expression of ECM gene programs compared to conventionally raised animals, indicating aggravation of obesity-related tissue fibrosis at thermoneutrality. In a model of primary cultured murine adipose progenitors, we found that exposure to β-hydroxybutyrate selectively reduced Tgfβ-dependent profibrotic responses of ECM genes like Ctgf, Loxl2 and Fn1. This effect is observed in both subcutaneous and visceral-derived adipose progenitors, as well as in 3T3-L1 fibroblasts. In 30 patients with obesity eligible for bariatric surgery, those with higher circulating β-hydroxybutyrate levels have lower subcutaneous adipose tissue fibrotic scores. Mechanistically, β-hydroxybutyrate limits Tgfβ-dependent collagen accumulation and reduces Smad2-3 protein expression and phosphorylation in visceral progenitors. Moreover, β-hydroxybutyrate induces the expression of the ZFP36 gene, encoding a post-transcriptional regulator that promotes the degradation of mRNA by binding to AU-rich sites within 3'UTRs. Importantly, complete ZFP36 deficiency in a mouse embryonic fibroblast line from null mice, or siRNA knock-down in primary progenitors, indicate that ZFP36 is required for β-hydroxybutyrate anti-fibrotic effects.. These data unravel the potential of β-hydroxybutyrate to limit adipose tissue matrix deposition, a finding that might exploited in an obesogenic context.

Topics: 3-Hydroxybutyric Acid; Adipocytes, Brown; Adipose Tissue, Brown; Adipose Tissue, White; Animals; Fibroblasts; Fibrosis; Humans; Mice; Obesity; Transforming Growth Factor beta; Tristetraprolin

Collagen is the main component of connective tissue surrounding adipocytes. Collagen cross-linking affects adipose remodeling, which is crucial for maintaining function and metabolic homeostasis of adipose tissue. However, the effects of obesity on collagen cross-linking and adipose fibrosis remain to be examined. Therefore, the objective of this study was to investigate obesity-induced collagen cross-linking in adipose tissue and explore the underlying mechanisms. We found that obesity increased mature nonreducible collagen cross-linking in white adipose tissue (WAT) of mice, which was associated with inhibition of AMPK, up-regulation of transforming growth factor-β (TGF-β) signaling and the expression of lysyl oxidase (LOX), a key enzyme catalyzing the synthesis of mature cross-linking products. In SVCs and 3T3-L1 adipocytes, AMPK activation by metformin or AICAR inhibited TGF-β1-induced fibrogenesis and expression of LOX, which was further confirmed by ectopic expression of AMPK WT and K45R mutant. Consistently, in vivo, knocking out AMPK increased fibrosis and collagen cross-linking. Our study showed that AMPK downregulation due to obesity increases TGF-β signaling and LOX expression, which enhances adipose fibrosis and collagen cross-linking. Thus, AMPK is a therapeutic target for ameliorating the obesity-induced fibrosis, improving metabolic health of adipose tissue.

Topics: Adipose Tissue; AMP-Activated Protein Kinases; Animals; Collagen; Fibrosis; Mice; Obesity; Protein-Lysine 6-Oxidase; Transforming Growth Factor beta

Unhealthy dietary patterns are the most important modifiable risk factors for obesity and overweight. This study aimed to examine the relationship between Dietary Phytochemical Index (DPI) and resting metabolic rate (RMR), mediated by inflammatory factors, in overweight and obese women.. A total of 404 women, aged 18-48 years, were included in the cross-sectional study. DPI was calculated using the 147-item food frequency questionnaire (FFQ). Anthropometric measurements, RMR, and blood biomarkers were assessed using standard protocols.. There was marginally significant association between adherence to DPI and RMR status in the crude model (OR = 1.41, 95% CI 0.94-2.11, P = 0.09). After adjusting for potential confounders, a significant association was seen between the DPI and increase RMR.per.kg (OR = 2.77, 95% CI 0.98-7.82, P = 0.05). Our results indicated that plasminogen activator inhibitor-1 (PAI-1), transforming growth factor (TGF-β), and monocyte chemoattractant protein-1 (MCP-1) had a mediatory effect on the association between RMR and DPI (P > 0.05). Indeed, it was shown that, PAI-1, TGF-β, and MCP-1 destroyed the significance of this association and could be considered as mediating markers. However, no mediating effect was observed for high-sensitivity C reactive protein (hs-CRP).. Adherence to DPI can improve the RMR by reducing levels of inflammatory markers, and may be considered as a treatment for obesity. However, more long-term studies are recommended.

Topics: Adolescent; Adult; Basal Metabolism; Biomarkers; Cross-Sectional Studies; Female; Humans; Middle Aged; Obesity; Overweight; Phytochemicals; Plasminogen Activator Inhibitor 1; Transforming Growth Factor beta; Young Adult

Extracellular vesicles (EVs) have been recently postulated as key players in metabolic disorders emerging as an alternative way of paracrine/endocrine communication. However, the nature of EVs shed by adipose tissue (AT) and their role in obesity is still very limited. Here, we isolated human morbid obese visceral (VAT) and subcutaneous (SAT) whole AT shed EVs from donors submitted to bariatric surgery to characterize their protein cargo by qualitative and quantitative/SWATH mass spectrometry analysis. We identified 574 different proteins shed by morbid obese VAT and 401 proteins in those from SAT, establishing the first obese AT EV proteome reference map. Only 50% of identified proteins in VAT vesicles were common to those in SAT; additionally, EVs shed by obese VAT showed more AT and obesity-related adipokines than SAT. Functional classification shows that obese VAT vesicles exhibit an enrichment of proteins implicated in AT inflammation and insulin resistance such as TGFBI, CAVN1, CD14, mimecan, thrombospondin-1, FABP-4 or AHNAK. Selected candidate biomarkers from the quantitative-SWATH analysis were validated in EVs from independent morbid obese and from moderate obese to lean individuals showing that morbid obese VAT vesicles are characterized by a diminution of syntenin 1 and the elevation of TGFBI and mimecan. Interestingly, TGFBI and mimecan containing vesicles could be detected and quantified at circulating level in plasma. Thus, a significant elevation of -TGFBI-EVs was detected on those obese patients with a history of T2D compared to nondiabetic, and an augmentation of mimecan-EVs in obese plasma compared to those in healthy lean individuals. Thus, we conclude that obese AT release functional EVs carrying AT and obesity candidate biomarkers which vary regarding the AT of origin. Our findings suggest that circulating EV-TGFBI may facilitate monitoring T2D status in obese patients, and EV-mimecan may be useful to track adiposity, and more precisely, visceral obesity.

Topics: Adipose Tissue, White; Adult; Biomarkers; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Extracellular Vesicles; Female; Humans; Intercellular Signaling Peptides and Proteins; Intra-Abdominal Fat; Male; Middle Aged; Obesity; Obesity, Morbid; Proteins; Subcutaneous Fat; Syntenins; Transforming Growth Factor beta

Leptin is a small molecule protein secreted by adipocytes, which can promote white fat browning through activating the hypothalamic nervous system and inhibiting downstream signaling pathways. Moreover, white fat browning has been proven to alleviate fat tissue fibrosis. This study explores the mechanism of leptin in regulating adipose tissue fibrosis and white fat browning. After treating mice with leptin, we screened out the recombinant integrin alpha 5 (ITGA5) through proteomics sequencing, which may play a role in adipose tissue fibrosis. Through real-time quantitative PCR (qPCR), western blotting (WB), hematoxylin-eosin (HE) staining, Masson's trichrome, immunofluorescence, immunohistochemistry, etc., the results showed that after leptin treated adipocytes, the expression of fibrosis-related genes and ITGA5 was significantly down-regulated in adipocytes. We constructed fibrosis model through transforming growth factor-β (TGF-β) and a high-fat diet (HFD), and treated with ITGA5 overexpression vector and interference fragments. The results indicated the expression of fibrosis-related genes were significantly down-regulated after interfering with ITGA5. After treating adipocytes with wortmannin, fibrosis-related gene expression was inhibited after overexpression of ITGA5. Moreover, after injecting mice with leptin, we also found that leptin significantly up-regulated the expression of adipose tissue browning-related genes. Overall, our research shows that leptin can inhibit the activation of phosphatidylinositol 3 kinase (PI3K)-protein kinase B (AKT) signaling pathway by reducing the expression of ITGA5, which could alleviate adipose tissue fibrosis, and further promote white fat browning. Our research provides a theoretical basis for further research on the effect of leptin in fibrosis-related adipose tissue metabolism.

Topics: Adipocytes, Brown; Adipocytes, White; Adipose Tissue, Brown; Adipose Tissue, White; Animals; Collagen Type I; Collagen Type III; Collagen Type VI; Diet, High-Fat; Fibrosis; Gene Expression Regulation; Integrins; Leptin; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Obesity; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Transforming Growth Factor beta; Wortmannin

Infections are a major complication of obesity, but the mechanisms responsible for impaired defense against microbes are not well understood. Here, we found that adipocyte progenitors were lost from the dermis during diet-induced obesity (DIO) in humans and mice. The loss of adipogenic fibroblasts from mice resulted in less antimicrobial peptide production and greatly increased susceptibility to

Topics: 3T3-L1 Cells; Adipocytes; Animals; Anti-Infective Agents; Cell Differentiation; Diet; Diet, High-Fat; Mice; Mice, Inbred C57BL; Obesity; PPAR gamma; Staphylococcal Infections; Staphylococcus aureus; Transforming Growth Factor beta

Topics: Adipocytes; Animals; CD52 Antigen; Cell Differentiation; Cells, Cultured; Datasets as Topic; Diabetes Mellitus, Type 2; Diet, High-Fat; Gene Expression Profiling; Gene Regulatory Networks; Genetic Predisposition to Disease; Humans; Intra-Abdominal Fat; Lymphocyte Activation; Mice; Mice, Knockout; Obesity; Primary Cell Culture; Prospective Studies; Protein Interaction Maps; Signal Transduction; Smad3 Protein; T-Lymphocytes; Transforming Growth Factor beta; Up-Regulation

Imbalance of the gut microbial community promotes inflammation and colorectal cancer (CRC). Previously, we demonstrated that freeze-dried Parabacteroides distasonis (Pd) suppressed obesity-driven colorectal tumorigenesis in mice. Here, we investigated if Pd could suppress the development of colon tumors in mice independent of obesity. Six-week-old male A/J mice were assigned to receive: (i) chow diet (CTR); (ii) chow with 0.04% wt/wt freeze-dried Pd (Pd-Early) or (iii) chow diet before switching to 0.04% Pd diet (Pd-Late). Mice remained on diet for 25 weeks with the switch for Pd-Late mice occurring after 19 weeks. All mice received 6 weekly injections of the colon carcinogen azoxymethane (AOM; 10 mg/kg I.P.) starting after 1 week on diet. Colon tumors were observed in 77, 55 and 40% in CTR, Pd-Early and Pd-Late mice, respectively (X2 = 0.047). Colonic expression of toll-like receptor 4, IL-4 and TNF-α was 40% (P < 0.01), 58% (P = 0.05) and 55% (P < 0.001) lower, respectively, in Pd-Early compared with CTR mice. Pd-Late mice displayed a 217% (P = 0.05) and 185% (P < 0.001) increase in colonic IL-10 and TGF-β expression, respectively, compared with CTR mice and similar increases in protein abundances were detected (47-145%; P < 0.05). Pd-Early and Pd-Late mice both demonstrated increased colonic expression of the tight junction proteins Zonula occludens-1 (P < 0.001) and occludin (P < 0.001) at the transcript (2-3-fold; P < 0.01) and protein level (30-50%; P < 0.05) relative to CTR. Our results support a protective role for Pd in colonic tumorigenesis and maintenance of intestinal epithelial barrier in AOM-treated mice.

Topics: Animals; Azoxymethane; Bacteroidetes; Carcinogenesis; Colon; Colonic Neoplasms; Humans; Inflammation; Interleukin-4; Intestinal Mucosa; Mice; Obesity; Signal Transduction; Toll-Like Receptor 4; Transforming Growth Factor beta

Extracellular vesicles (EVs) have recently emerged as a relevant way of cell to cell communication, and its analysis has become an indirect approach to assess the cell/tissue of origin status. However, the knowledge about their nature and role on metabolic diseases is still very scarce. We have established an insulin resistant (IR) and two lipid (palmitic/oleic) hypertrophied adipocyte cell models to isolate EVs to perform a protein cargo qualitative and quantitative Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH) analysis by mass spectrometry. Our results show a high proportion of obesity and IR-related proteins in pathological EVs; thus, we propose a panel of potential obese adipose tissue EV-biomarkers. Among those, lipid hypertrophied vesicles are characterized by ceruloplasmin, mimecan, and perilipin 1 adipokines, and those from the IR by the striking presence of the adiposity and IR related transforming growth factor-beta-induced protein ig-h3 (TFGBI). Interestingly, functional assays show that IR and hypertrophied adipocytes induce differentiation/hypertrophy and IR in healthy adipocytes through secreted EVs. Finally, we demonstrate that lipid atrophied adipocytes shed EVs promote macrophage inflammation by stimulating IL-6 and TNFα expression. Thus, we conclude that pathological adipocytes release vesicles containing representative protein cargo of the cell of origin that are able to induce metabolic alterations on healthy cells probably exacerbating the disease once established.

Topics: Adipocytes; Adipokines; Animals; Ceruloplasmin; Extracellular Matrix Proteins; Extracellular Vesicles; Insulin Resistance; Interleukin-6; Lipid Droplets; Mice; Obesity; Perilipin-1; RAW 264.7 Cells; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Non-alcoholic fatty liver disease (NAFLD) is gaining in importance and is linked to obesity. Especially, the development of fibrosis and portal hypertension in NAFLD patients requires treatment. Transgenic TGR(mREN2)27 rats overexpressing mouse renin spontaneously develop NAFLD with portal hypertension but without obesity. This study investigated the additional role of obesity in this model on the development of portal hypertension and fibrosis. Obesity was induced in twelve-week old TGR(mREN2)27 rats after receiving Western diet (WD) for two or four weeks. Liver fibrosis was assessed using standard techniques. Hepatic expression of transforming growth factor-β1 (TGF-β1), collagen type Iα1, α-smooth muscle actin, and the macrophage markers Emr1, as well as the chemoattractant Ccl2, interleukin-1β (IL1β) and tumor necrosis factor-α (TNFα) were analyzed. Assessment of portal and systemic hemodynamics was performed using the colored microsphere technique. As expected, WD induced obesity and liver fibrosis as confirmed by Sirius Red and Oil Red O staining. The expression of the monocyte-macrophage markers, Emr1, Ccl2, IL1β and TNFα were increased during feeding of WD, indicating infiltration of macrophages into the liver, even though this increase was statistically not significant for the EGF module-containing mucin-like receptor (Emr1) mRNA expression levels. Of note, portal pressure increased with the duration of WD compared to animals that received a normal chow. Besides obesity, WD feeding increased systemic vascular resistance reflecting systemic endothelial and splanchnic vascular dysfunction. We conclude that transgenic TGR(mREN2)27 rats are a suitable model to investigate NAFLD development with liver fibrosis and portal hypertension. Tendency towards elevated expression of Emr1 is associated with macrophage activity point to a significant role of macrophages in NAFLD pathogenesis, probably due to a shift of the renin-angiotensin system towards a higher activation of the classical pathway. The hepatic injury induced by WD in TGR(mREN2)27 rats is suitable to evaluate different stages of fibrosis and portal hypertension in NAFLD with obesity.

Topics: Animals; Chemokine CCL2; Diet, Western; Disease Models, Animal; Gene Expression Regulation; Hypertension, Portal; Mice; Non-alcoholic Fatty Liver Disease; Obesity; Peptidyl-Dipeptidase A; Rats; Rats, Transgenic; Receptor, Angiotensin, Type 1; Receptors, Cell Surface; Renin; Transforming Growth Factor beta

TGFβ is a key player in cartilage homeostasis and OA pathology. However, few data are available on the role of TGFβ signalling in the different OA phenotypes. Here, we analysed the TGFβ pathway by transcriptomic analysis in six mouse models of OA.. We have brought together seven expert laboratories in OA pathophysiology and, used inter-laboratories standard operating procedures and quality controls to increase experimental reproducibility and decrease bias. As none of the available OA models covers the complexity and heterogeneity of the human disease, we used six different murine models of knee OA: from post-traumatic/mechanical models (meniscectomy (MNX), MNX and hypergravity (HG-MNX), MNX and high fat diet (HF-MNX), MNX and seipin knock-out (SP-MNX)) to aging-related OA and inflammatory OA (collagenase-induced OA (CIOA)). Four controls (MNX-sham, young, SP-sham, CIOA-sham) were added. OsteoArthritis Research Society International (OARSI)-based scoring of femoral condyles and ribonucleic acid (RNA) extraction from tibial plateau samples were done by single operators as well as the transcriptomic analysis of the TGFβ family pathway by Custom TaqMan® Array Microfluidic Cards.. The transcriptomic analysis revealed specific gene signatures in each of the six models; however, no gene was deregulated in all six OA models. Of interest, we found that the combinatorial Gdf5-Cd36-Ltbp4 signature might discriminate distinct subgroups of OA: Cd36 upregulation is a hallmark of MNX-related OA while Gdf5 and Ltbp4 upregulation is related to MNX-induced OA and CIOA.. These findings stress the OA animal model heterogeneity and the need of caution when extrapolating results from one model to another.

Topics: Animals; Arthritis, Experimental; CD36 Antigens; Collagenases; Diet, High-Fat; Disease Models, Animal; Gene Expression Profiling; Growth Differentiation Factor 5; GTP-Binding Protein gamma Subunits; Hypergravity; Latent TGF-beta Binding Proteins; Meniscectomy; Metabolic Syndrome; Mice; Mice, Knockout; Obesity; Osteoarthritis; Transcriptome; Transforming Growth Factor beta

Obesity due to overnutrition causes adipose tissue dysfunction, which is a critical pathological step on the road to type 2 diabetes (T2D) and other metabolic disorders. In this study, we conducted an unbiased investigation into the fundamental molecular mechanisms by which adipocytes transition to an unhealthy state during obesity.. We used nuclear tagging and translating ribosome affinity purification (NuTRAP) reporter mice crossed with Adipoq-Cre mice to determine adipocyte-specific 1) transcriptional profiles (RNA-seq), 2) promoter and enhancer activity (H3K27ac ChIP-seq), 3) and PPARγ cistrome (ChIP-seq) profiles in mice fed chow or a high-fat diet (HFD) for 10 weeks. We also assessed the impact of the PPARγ agonist rosiglitazone (Rosi) on gene expression and cellular state of adipocytes from the HFD-fed mice. We integrated these data to determine the transcription factors underlying adipocyte responses to HFD and conducted functional studies using shRNA-mediated loss-of-function approaches in 3T3-L1 adipocytes.. Adipocytes from the HFD-fed mice exhibited reduced expression of adipocyte markers and metabolic genes and enhanced expression of myofibroblast marker genes involved in cytoskeletal organization, accompanied by the formation of actin filament structures within the cell. PPARγ binding was globally reduced in adipocytes after HFD feeding, and Rosi restored the molecular and cellular phenotypes of adipocytes associated with HFD feeding. We identified the TGFβ1 effector protein SMAD to be enriched at HFD-induced promoters and enhancers and associated with myofibroblast signature genes. TGFβ1 treatment of mature 3T3-L1 adipocytes induced gene expression and cellular changes similar to those seen after HFD in vivo, and knockdown of Smad3 blunted the effects of TGFβ1.. Our data demonstrate that adipocytes fail to maintain cellular identity after HFD feeding, acquiring characteristics of a myofibroblast-like cell type through reduced PPARγ activity and elevated TGFβ-SMAD signaling. This cellular identity crisis may be a fundamental mechanism that drives functional decline of adipose tissues during obesity.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Adipose Tissue; Animals; Cell Differentiation; Diet, High-Fat; Humans; Insulin; Insulin Resistance; Mice; Mice, Inbred C57BL; Mice, Transgenic; Obesity; PPAR gamma; Rosiglitazone; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

While plasminogen activator inhibitor-1 (PAI-1) is known to potentiate cellular migration via proteolytic regulation, this adipokine is implicated as an oncogenic ligand in the tumor microenvironment. To understand the underlying paracrine mechanism, here, we conduct transcriptomic analysis of 1,898 endometrial epithelial cells (EECs) exposed and unexposed to PAI-1-secreting adipose stromal cells. The PAI-1-dependent action deregulates crosstalk among tumor-promoting and tumor-repressing pathways, including transforming growth factor β (TGF-β). When PAI-1 is tethered to lipoprotein receptor-related protein 1 (LRP1), the internalized signaling causes downregulation of SMAD4 at the transcriptional and post-translational levels that attenuates TGF-β-related transcription programs. Repression of genes encoding the junction and adhesion complex preferentially occurs in SMAD4-underexpressed EECs of persons with obesity. The findings highlight a role of PAI-1 signaling that renders ineffective intercellular communication for the development of adiposity-associated endometrial cancer.

Topics: Adipose Tissue; Down-Regulation; Endometrial Neoplasms; Female; Gene Expression Regulation, Neoplastic; Humans; Junctional Adhesion Molecules; Low Density Lipoprotein Receptor-Related Protein-1; Obesity; Plasminogen Activator Inhibitor 1; Protein Binding; Proteolysis; Proteomics; Smad4 Protein; Stromal Cells; Transcription, Genetic; Transforming Growth Factor beta; Tumor Microenvironment; Ubiquitin

The mesenchymal stromal cells (MSCs) residing within the stromal component of visceral adipose tissue appear to be greatly affected by obesity, with impairment of their functions and presence of senescence. To gain further insight into these phenomena, we analyzed the changes in total proteome content and secretome of mouse MSCs after a high-fat diet (HFD) treatment compared to a normal diet (ND). In healthy conditions, MSCs are endowed with functions mainly devoted to vesicle trafficking. These cells have an immunoregulatory role, affecting leukocyte activation and migration, acute inflammation phase response, chemokine signaling, and platelet activities. They also present a robust response to stress. We identified four signaling pathways (TGF-β, VEGFR2, HMGB1, and Leptin) that appear to govern the cells' functions. In the obese mice, MSCs showed a change in their functions. The immunoregulation shifted toward pro-inflammatory tasks with the activation of interleukin-1 pathway and of Granzyme A signaling. Moreover, the methionine degradation pathway and the processing of capped intronless pre-mRNAs may be related to the inflammation process. The signaling pathways we identified in ND MSCs were replaced by MET, WNT, and FGFR2 signal transduction, which may play a role in promoting inflammation, cancer, and aging.

Topics: Aging; Animals; Diet, High-Fat; Granzymes; HMGB1 Protein; Inflammation; Interleukin-1; Intra-Abdominal Fat; Leptin; Mesenchymal Stem Cells; Methionine; Mice; Obesity; Proteome; Proto-Oncogene Proteins c-met; Receptor, Fibroblast Growth Factor, Type 2; RNA Precursors; RNA Processing, Post-Transcriptional; Secretory Vesicles; Signal Transduction; Transforming Growth Factor beta; Vascular Endothelial Growth Factor Receptor-2; Wnt Signaling Pathway

Consumption of high fat diet (HFD) is associated with increased cardiovascular risk factors among elderly people. Aging and obesity induced-cardiac remodeling includes hypertrophy and fibrosis. Gelsolin (GSN) induces cardiac hypertrophy and TGF-β, a key cytokine, which induces fibrosis. The relationship between TGF-β and GSN in aging induced cardiac remodeling is still unknown. We evaluated the expressions of TGF-β and GSN in HFD fed 22 months old aging SD rats, followed by the administration of either probucol or alcalase potato protein hydrolysate (APPH). Western blotting and Masson trichrome staining showed that APPH (45 and 75 mg/kg/day) and probucol (500 mg/kg/day) treatments significantly reduced the aging and HFD-induced hypertrophy and fibrosis. Echocardiograph showed that the performance of the hearts was improved in APPH, and probucol treated HFD aging rats. Serum from all rats was collected and H9c2 cells were cultured with collected serums separately. The GSN dependent hypertrophy was inhibited with an exogenous TGF-β in H9c2 cells cultured in HFD+ APPH treated serum. Thus, we propose that along with its role in cardiac fibrosis, TGF-β also acts as an upstream activator of GSN dependent hypertrophy. Hence, TGF-β in serum could be a promising therapeutic target for cardiac remodeling in aging and/or obese subjects.

Topics: Administration, Oral; Aging; Animals; Cells, Cultured; Diet, High-Fat; Gelsolin; Heart Diseases; Myocardium; Obesity; Protein Hydrolysates; Rats; Rats, Sprague-Dawley; Signal Transduction; Solanum tuberosum; Subtilisins; Transforming Growth Factor beta

Obesity increases the risk of diabetes mellitus (DM) and hypertension. We aimed to analyze the serum levels of cytokines that have relevance to the pathologies including, interleukin-4 (IL-4), transforming growth factor-β (TGF-β), interferon-γ (IFN-γ), and IL-6 cytokines of overweight men with DM and/or hypertension.. The study collected serum from 164 men. The sample population contained, 54 overweight men without DM or hypertension (control [CTL] group), 36 men with both DM and hypertension (DH group), 20 men with DM but no hypertension (D group), and 54 had hypertension without DM (H).. The main results showed that the concentration of IFN-γ in the DH group was significantly higher than the D, H, and CTL groups, IL-6 in DH and D groups was significantly lower than the CTL group. The serum level of TGF-β and IL-4 cytokines did not show any significant differences across the four groups. Serum levels of IL-6 were also significantly lower in untreated patients in D group than controls and in DH when compared with H groups.. In conclusion, it appears that the proinflammatory and anti-inflammatory cytokines either play a significant role in the pathogenesis of hypertension and DM or serve as markers for these pathologies. Accordingly, increased serum levels of IFN-γ may participate in the pathogenesis of hypertension in the diabetic patients and decreased IL-6 is associated with type 2 DM.

Topics: Antihypertensive Agents; Diabetes Mellitus, Type 2; Humans; Hypertension; Hypoglycemic Agents; Interferon-gamma; Interleukin-4; Interleukin-6; Male; Middle Aged; Obesity; Transforming Growth Factor beta

Exercise is an effective therapy for insulin resistance. However, the underlying mechanism remains to be elucidated. Previous research demonstrated that TGFβ-activated kinase 1 (TAK1)-dependent signaling plays a crucial character in hepatic insulin resistance. Hepatic ubiquitin specific protease 4 (USP4), USP18, and dual-specificity phosphatases 14 (DUSP14) can suppress TAK1 phosphorylation, besides tumor necrosis factor receptor-associated factor 3 (TRAF3) and tripartite motif 8 (TRIM8) promote its phosphorylation. In this study, we tried to verify our hypothesis that exercise improves insulin resistance in high-fat diet (HFD)-induced obese (DIO) rats via regulating the TAK1 dependent signaling and TAK1 regulators in liver. Forty male Sprague-Dawley rats were randomized into four groups (n = 10): standard diet and sedentary as normal control; fed on HFD and DIO-sedentary; fed on HFD and DIO-chronic exercise; and fed on HFD and DIO-acute exercise. HFD feeding resulted in increased body weight, visceral fat mass, serum FFAs and hepatic lipid deposition, but decreased hepatic glycogen content and insulin sensitivity. Moreover, hepatic TRAF3 and TRIM8 protein levels increased, whereas USP4, USP18, and DUSP14 protein levels were decreased under obese status, which resulted in enhanced TAK1 phosphorylation and impaired insulin signaling. Exercise training, containing chronic and acute mode, both ameliorated insulin resistance. Meanwhile, decreased TAK1, c-Jun N-terminal kinase 1 (JNK1), and insulin receptor substrate 1 (IRS1) phosphorylation enhanced Akt phosphorylation in liver. Moreover, exercise enhanced USP4 and DUSP14 protein levels, whereas decreased TRIM8 protein levels in obese rats' liver. These results showed that exercise triggered a crucial modulation in TAK1-dependent signaling and its regulators in obese rats' liver, and distinct improvement in insulin sensitivity, which provide new insights into the mechanism by which physical exercise improves insulin resistance.

Topics: Animals; Carrier Proteins; Diet, High-Fat; Insulin; Insulin Resistance; Intra-Abdominal Fat; Liver; Male; MAP Kinase Kinase Kinases; Obesity; Phosphorylation; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Signal Transduction; TNF Receptor-Associated Factor 3; Transforming Growth Factor beta; Ubiquitin-Specific Proteases

It is well known that obesity contributes to the development of systemic inflammatory responses, which in turn may be involved in the process of interstitial fibrosis and left ventricular (LV) remodelling. Activation of pro-inflammatory factors such as transforming growth factor β (TGF-β) can directly stimulate mitogen-activated protein kinase (MAPK) p38 and JNK. The aim of the study was to evaluate the level of TGF-β and MAPK p38 and JNK in the LV in Sprague Dawley (SPRD) rats maintained on a high fat diet (HFD). The SPRD rats from 4 weeks of age were on a normal fat diet (NFD) or a HFD for 12 weeks (NFD-16-week-old rats, NFD 16-wk; or HFD-16-week-old rats, HFD 16-wk) or 16 weeks (NFD-20-week-old rats, NFD 20-wk; or HFD-20-week-old rats, HFD 20-wk). At the end of the experiment, blood and LV were collected from all rats for further analysis (biochemical, Real Time PCR and immunohistochemical analysis). TGF-β mRNA expression did not differ between the study groups of rats. However, p38 MAPK mRNA expression was significantly lower in the HFD 20-wk rats than in both the HFD 16-wk rats and the NFD 20-wk rats. c-jun mRNA expression was significantly higher in the HFD 16-wk rats than in the NFD 16-wk rats. There was significantly lower expression of c-jun mRNA in the HFD 20-wk rats and in the NFD 20-wk rats than in the HFD 16-wk rats and in the NFD 16-wk rats, respectively. TGF-β type II receptor (TβRII) protein demonstrated only cytoplasmic reactivity, while p38 MAPK protein and c-jun protein showed both nuclear and cytoplasmic reactivity. The results suggest that a high fat diet and in two time intervals significantly influence the expression of p38 MAPK and JNK in the LV. However, demonstrating their potential involvement in the processes of interstitial myocardial fibrosis and left ventricular remodeling requires further research.

Topics: Animals; Diet, High-Fat; Fibrosis; Heart Diseases; Heart Ventricles; Male; Myocardium; Obesity; p38 Mitogen-Activated Protein Kinases; Rats; Transforming Growth Factor beta

Chemerin is an adipocytokine that participates in glycolipid metabolism; however, its association with type 2 diabetes (T2DM) with lower extremity macroangiopathy (T2DM-V) has rarely been reported. This study explored the association of chemerin and inflammatory factors with body fat parameters, glucolipid metabolism, and insulin resistance (IR) in T2DM and T2DM-V. Patients were classified into normal glucose regulation (NGR), T2DM, and T2DM-V groups. Serum chemerin, glucolipid metabolic parameters, transforming growth factor (TGF)-β, interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, and fasting insulin levels were measured along with HOMA-IR, body mass index (BMI), and waist-to-stature ratio (WSR). Serum chemerin, TGF-β, IL-6, and MCP-1 levels were significantly higher in T2DM groups than in NGR group, and BMI, WSR, fasting plasma glucose (FPG), 2hPG, glycated hemoglobin (HbA1c), triglycerides (TG), and HOMA-IR were higher in T2DM-V subgroups with moderate or severe lower extremity macroangiopathy than in NGR group, simple T2DM group, and T2DM-V subgroup with mild macroangiopathy. FPG, 2hPG, HbA1c, TG, and HOMA-IR were higher in T2DM-V subgroup with severe macroangiopathy than in T2DM-V with moderate macroangiopathy (p < 0.05). In all groups, serum chemerin levels were positively correlated with BMI, WSR, FPG, 2hPG, HbA1c, fasting insulin, aspartate transaminase, TG, TGF-β, IL-6, and HOMA-IR (p < 0.05) and negatively correlated with high-density lipoprotein cholesterol [HDL-c] (p < 0.05). Multiple stepwise regression analysis showed that 2hPG, HbA1c, and HDL-c were independent predictors of serum chemerin levels (β = -0.768, -0.122, -0.115, and 3.261, respectively; p < 0.01). Collectively, chemerin, factors associated with obesity, pathological and physiological changes in glucolipid metabolism, and inflammatory factors may promote the development of T2DM macroangiopathy.

Topics: Adult; Aged; Blood Glucose; Body Height; Body Mass Index; Chemokine CCL2; Chemokines; Cholesterol, HDL; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Glucose Tolerance Test; Glycated Hemoglobin; Glycolipids; Humans; Inflammation; Insulin; Insulin Resistance; Interleukin-6; Male; Middle Aged; Obesity; Regression Analysis; Transforming Growth Factor beta; Triglycerides; Waist-Height Ratio

Recent studies have shown that dysfunction and decrease of regulatory T cells (Tregs) correlates with insulin resistance (IR), one of the most significant mechanisms for type 2 diabetes mellitus (T2DM). To examine potential relationships among Tregs, IR, blood lipid content, and related cytokines, we investigated the frequency of CD4+CD25+Foxp3+ Tregs, as well as expression levels of interleukin 10 (IL-10) and transforming growth factor-β (TGF-β) in newly diagnosed T2DM patients.. Fifty-one newly diagnosed T2DM patients and 55 control individuals were enrolled. According to body mass index (BMI), the T2DM patients were grouped into non-obese and obese groups. Blood was collected in ethylene diamine tetraacetic acid (EDTA) anticoagulant tubes for detection of CD4+CD25+Foxp3+ Tregs by flow cytometry. Serum was collected to quantify IL-10 and TGF-β levels by enzyme-linked immunosorbent assay (ELISA). By comparing percentages of Tregs between non-obese and obese groups, correlation with Treg frequency, homeostasis model assessment of insulin resistance (HOMA-IR), IL-10 and TGF-β was examined.. The percentage of CD4+CD25+Foxp3+ Tregs in the newly diagnosed T2DM group was significantly lower than in the control group (P<0.01). Further, levels of IL-10 and TGF-β were also lower in the T2DM group (P<0.05). The level of IL-10 was remarkably lower in the obese group than in the non-obese and the control groups (P<0.01), but there was no significant difference between non-obese group and the control group. The level of TGF-β was lower in obese group than in the control group (P<0.05). There was no significant difference between non-obese group and the control group. The frequency of CD4+CD25+Foxp3+ Tregs in the obese group was significantly lower than in the non-obese group (P<0.05). In the obese group, the percentage of Tregs negatively correlated with HOMA-IR and positively correlated with TGF-β (P<0.05). There was no obvious correlation between Treg and HOMA-IR in the non-obese group.. The percentage of CD4+CD25+Foxp3+ Tregs and levels of related cytokines IL-10 and TGF-β were precipitously decreased in newly diagnosed T2DM patients. Therefore, the function of Tregs in limiting the proinflammatory milieu represents an important pathogenic mediator of the development of obesity-induced IR in newly diagnosed T2DM patients. Notably, TGF-β may play an important role in this process. Thus, enhancing expression of Tregs may improve IR in newly diagnosed T2DM patients with obesity.

Topics: Adult; Body Mass Index; Diabetes Mellitus, Type 2; Female; Forkhead Transcription Factors; Humans; Insulin Resistance; Interleukin-10; Interleukin-2 Receptor alpha Subunit; Male; Middle Aged; Obesity; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

Transforming growth factor-β (TGF-β), interleukin-10 (IL-10), and forkhead box P3 (Foxp3) have important roles in breast cancer development. Previous studies confirmed a correlation between these immune molecules and tumor characteristics, but their association with nutritional status in breast cancer is largely unknown. We aimed to investigate the association between body mass index (BMI), hemoglobin, total protein, albumin, globulin (GLB), albumin/GLB ratio (AGR), pre-albumin, prognostic nutritional index, and TGF-β, IL-10, and Foxp3 mRNA expression in patients with breast cancer. Quantitative real-time PCR was used to detect the mRNA expression of TGF-β, IL-10, and Foxp3 in the peripheral blood of 107 patients with breast cancer and 21 healthy controls. We found that TGF-β mRNA levels were 2.6-fold, 3.2-fold, and 2.3-fold higher in patients with low BMI (<23), low AGR, and high GLB, respectively, than in their counterparts (P < 0.05). In addition, IL-10 mRNA expression levels in patients with normal BMI (<23) were 2.8-fold and 3.5-fold higher than in those who were overweight (23≤ BMI <25) and obese (BMI ≥ 25), respectively (P < 0.05). In addition, TGF-β, IL-10, and Foxp3 mRNA levels were significantly higher in patients with breast cancer than in healthy controls (P < 0.05). In summary, our results suggest that nutritional status, especially BMI, may strongly affect systematic immune function in patients with breast cancer. © 2018 IUBMB Life, 70(3):237-245, 2018.

Topics: Adult; Body Mass Index; Breast Neoplasms; Female; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Humans; Interleukin-10; Middle Aged; Obesity; RNA, Messenger; Transforming Growth Factor beta

Adipose tissue fibrosis is associated with inflammation and insulin resistance in human obesity. In particular, visceral fat fibrosis is correlated with hyperlipidemia and ectopic fat accumulation. Myocardin-related transcription factor A (MRTFA) is an important coactivator that mediates the transcription of extracellular matrix and other fibrogenic genes. Here, we examine the role of MRTFA in the development of adipose tissue fibrosis and identify a signaling pathway that regulates the fate of vascular progenitors. We demonstrate that obesity induces the formation of Sca1

Topics: Adipocytes; Adipose Tissue; Animals; Cell Differentiation; Chronic Disease; Energy Metabolism; Fatty Liver; Fibrosis; Hypertrophy; Inflammation; Insulin Resistance; Integrin alpha5; Mice, Inbred C57BL; Models, Biological; Myofibroblasts; Obesity; Stem Cells; Trans-Activators; Transforming Growth Factor beta

Obesity and its associated complications such as insulin resistance and non-alcoholic fatty liver disease are reaching epidemic proportions. In mice, the TGF-β superfamily is implicated in the regulation of white and brown adipose tissue differentiation. The kielin/chordin-like protein (KCP) is a secreted regulator of the TGF-β superfamily pathways that can inhibit both TGF-β and activin signals while enhancing bone morphogenetic protein (BMP) signaling. However, KCP's effects on metabolism and obesity have not been studied in animal models. Therefore, we examined the effects of KCP loss or gain of function in mice that were maintained on either a regular or a high-fat diet. KCP loss sensitized the mice to obesity and associated complications such as glucose intolerance and adipose tissue inflammation and fibrosis. In contrast, transgenic mice that expressed KCP in the kidney, liver, and adipose tissues were resistant to developing high-fat diet-induced obesity and had significantly reduced white adipose tissue. Moreover, KCP overexpression shifted the pattern of SMAD signaling

Topics: Adipocytes; Animals; Bone Morphogenetic Protein 7; Carrier Proteins; Dietary Fats; Metabolic Syndrome; Mice; Mice, Knockout; Obesity; Organ Specificity; Signal Transduction; Smad3 Protein; Transforming Growth Factor beta

Reduced physical activity and increased intake of calorically-dense diets are the main risk factors for obesity, glucose intolerance, and type 2 diabetes. Chronic overnutrition and hyperglycemia can alter gene expression, contributing to long-term obesity complications. While caloric restriction can reduce obesity and glucose intolerance, it is currently unknown whether it can effectively reprogram transcriptome to a pre-obesity level. The present study addressed this question by the preliminary examination of the transcriptional dynamics in skeletal muscle after exposure to overnutrition and following caloric restriction.. Six male rhesus macaques of 12-13 years of age consumed a high-fat western-style diet for 6 months and then were calorically restricted for 4 months without exercise. Skeletal muscle biopsies were subjected to longitudinal gene expression analysis using next-generation whole-genome RNA sequencing. In spite of significant weight loss and normalized insulin sensitivity, the majority of WSD-induced (n = 457) and WSD-suppressed (n = 47) genes remained significantly dysregulated after caloric restriction (FDR ≤0.05). The Metacore. Western-style diet, in the absence of exercise, induced skeletal muscle transcriptional programing, which persisted even after insulin resistance and glucose intolerance were completely reversed with caloric restriction.

Topics: Animals; Caloric Restriction; Cytokines; Diet, Western; Energy Metabolism; Gene Expression Profiling; Macaca mulatta; Male; Muscle, Skeletal; Obesity; Signal Transduction; Transforming Growth Factor beta; Up-Regulation

Nonalcoholic fatty liver disease (NAFLD) is now the most common progressive liver disease in developed countries and is the second leading indication for liver transplantation due to the extensive fibrosis it causes. NAFLD progression is thought to be tied to chronic low-level type 1 inflammation originating in the adipose tissue during obesity; however, the specific immunological mechanisms regulating the progression of NAFLD-associated fibrosis in the liver are unclear. To investigate the immunopathogenesis of NAFLD more completely, we investigated adipose dysfunction, nonalcoholic steatohepatitis (NASH), and fibrosis in mice that develop polarized type 1 or type 2 immune responses. Unexpectedly, obese interleukin-10 (IL-10)/IL-4-deficient mice (type 1-polarized) were highly resistant to NASH. This protection was associated with an increased hepatic interferon-γ (IFN-γ) signature. Conversely, IFN-γ-deficient mice progressed rapidly to NASH with evidence of fibrosis dependent on transforming growth factor-β (TGF-β) and IL-13 signaling. Unlike increasing type 1 inflammation and the marked loss of eosinophils seen in expanding adipose tissue, progression of NASH was associated with increasing eosinophilic type 2 liver inflammation in mice and human patient biopsies. Finally, simultaneous inhibition of TGF-β and IL-13 signaling attenuated the fibrotic machinery more completely than TGF-β alone in NAFLD-associated fibrosis. Thus, although type 2 immunity maintains healthy metabolic signaling in adipose tissues, it exacerbates the progression of NAFLD collaboratively with TGF-β in the liver.

Topics: Adipose Tissue; Animals; Diet, High-Fat; Disease Progression; Eosinophils; Humans; Immunity; Inflammation; Interferon-gamma; Liver Cirrhosis; Male; Metabolic Diseases; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Transforming Growth Factor beta

Adipose tissue resident macrophages have important roles in the maintenance of tissue homeostasis and regulate insulin sensitivity for example by secreting pro-inflammatory or anti-inflammatory cytokines. Here, we show that M2-like macrophages in adipose tissue regulate systemic glucose homeostasis by inhibiting adipocyte progenitor proliferation via the CD206/TGFβ signaling pathway. We show that adipose tissue CD206

Topics: Adipocytes; Adipocytes, White; Adipose Tissue, White; Animals; Cell Differentiation; Cell Proliferation; Diet, High-Fat; Glucose; Insulin Resistance; Lectins, C-Type; Macrophages; Mannose Receptor; Mannose-Binding Lectins; Mice, Inbred C57BL; Mice, Transgenic; Obesity; Receptors, Cell Surface; Signal Transduction; Stem Cells; Transforming Growth Factor beta

Macrophage inhibitory cytokine-1/growth differentiation factor 15 (MIC-1/GDF15) is a divergent transforming growth factor (TGFβ) superfamily cytokine implicated in biological and disease processes including metabolism, cancer, and chronic inflammation, but whose receptor has remained elusive. Four laboratories have recently identified GFRAL, an orphan receptor of the glial-derived neurotrophic factor (GDNF) receptor α family, as the receptor for MIC-1/GDF15, signaling though the coreceptor Ret. These data identify a new systemic to central nervous system (CNS) circuit that regulates metabolism in response to stress and which could be targeted to treat both severe obesity and anorexia/cachexia syndrome.

Topics: Animals; Cachexia; Central Nervous System; Glial Cell Line-Derived Neurotrophic Factor Receptors; Growth Differentiation Factor 15; Humans; Inflammation; Obesity; Orphan Nuclear Receptors; Proto-Oncogene Proteins c-ret; Transforming Growth Factor beta

The aim of this study was to investigate the effect of probiotic strains of Lactobacillus casei IMV B-7280, Bifidobacterium animalis VKL, B. animalis VKB on the pro- and anti-inflammatory cytokines production in Wistar male rats with monosodium glutamate (MSG)-induced obesity. It was established that neonatal administration of MSG to rats leads to increasing levels of the interleukin (IL)-1β and IL-12, and to decreasing ofthe IL-4, IL-10 and tumor growthfactor (TGF)-β levels in the bloodserum. After administration of the B. animalis VKL - B. animalis VKB - L. casei IMV B-7280 composition to obese rats the level of the IL-lP in blood serum wasn't differ from that in the obese rats, that didn't receive of the probiotic bacteria. But there was no statistically signifcant difference comparing with intact rats. The level of the IL-12B p4O in blood serum was decreased under influence of the B. animalis VKL - B. animalis VKB - L. casei IMV B-7280 composition (18.9%, p < 0.05) and B. animalis VKL (10.5%, p < 0.05) compared with obese rats, not receiving probiotic bacteria, but remained higher than in intact animals. After administration to obese rats ofthe B. animalis VKL - B. animalis VKB - L. casei IMV B-7280 composition the levels ofthe IL-4, IL- 10 and TGF-β increased in blood serum comparing with obese rats, not receiving probiotic bacteria. The level of the IL-10 also increased under influence of the B. animalis VKB, and IL-4 - under influence of the L. casei IMVB-7280. Our results suggest that these probiotic bacteria and probiotic composition are able to down-regulation the inflammation in rats with MSG-induced obesity but the strongest anti-inflammatory effects have probiotic composition. The ability of lactobacilli and bifdobacteria to alter the pro- and anti-inflammatory cytokines production, opens perspectives to create new treatments for obesity and metabolic syndrome based on probiotics.

Topics: Animals; Animals, Newborn; Anti-Inflammatory Agents; Bifidobacterium; Gene Expression Regulation; Inflammation; Interleukin-10; Interleukin-12; Interleukin-1beta; Interleukin-4; Lacticaseibacillus casei; Obesity; Probiotics; Rats; Rats, Wistar; Sodium Glutamate; Transforming Growth Factor beta

Hypothalamic inflammation was recently found to mediate obesity-related hypertension, but the responsible upstream mediators remain unexplored. In this study, we show that dietary obesity is associated with extracellular release of mitochondrial DNA (mtDNA) into the cerebrospinal fluid and that central delivery of mtDNA mimics transforming growth factor-β (TGFβ) excess to activate downstream signaling pathways. Physiological study reveals that central administration of mtDNA or TGFβ is sufficient to cause hypertension in mice. Knockout of the TGFβ receptor in proopiomelanocortin neurons counteracts the hypertensive effect of not only TGFβ but also mtDNA excess, while the hypertensive action of central mtDNA can be blocked pharmacologically by a TGFβ receptor antagonist or genetically by TGFβ receptor knockout. Finally, we confirm that obesity-induced hypertension can be reversed through central treatment with TGFβ receptor antagonist. In conclusion, circulating mtDNA in the brain employs neural TGFβ pathway to mediate a central inflammatory mechanism of obesity-related hypertension.

Topics: Animals; Benzamides; Blood Pressure; Blotting, Western; Diet, High-Fat; Dioxoles; DNA, Mitochondrial; Hypertension; Hypothalamus; Male; Mice; Mice, Knockout; Neurons; Obesity; Pro-Opiomelanocortin; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Third Ventricle; Transforming Growth Factor beta; Transforming Growth Factor beta1

Obesity increases the risk of distant metastatic recurrence and reduces breast cancer survival. However, the mechanisms behind this pathology and identification of relevant therapeutic targets are poorly defined. Plasma free fatty acids (FFA) levels are elevated in obese individuals. Here we report that TGFβ transiently activates ERK and subsequently phosphorylates SMAD4 at Thr277, which facilitates a SMAD4-USP9x interaction, SMAD4 nuclear retention, and stimulates TGFβ/SMAD3-mediated transcription of Twist and Snail. USP9x inhibited the E3 ubiquitin-protein ligase TIF1γ from binding and monoubiquitinating SMAD4, hence maintaining the SMAD4 nuclear retention. FFA further facilitated TGFβ-induced ERK activation, SMAD4 phosphorylation, and nuclear retention, promoting TGFβ-dependent cancer progression. Inhibition of ERK and USP9x suppressed obesity-induced metastasis. In addition, clinical data indicated that phospho-ERK and -SMAD4 levels correlate with activated TGFβ signaling and metastasis in overweight/obese patient breast cancer specimens. Altogether, we demonstrate the vital interaction of USP9x and SMAD4 for governing TGFβ signaling and dyslipidemia-induced aberrant TGFβ activation during breast cancer metastasis.

Topics: Animals; Apoptosis; Biomarkers, Tumor; Breast Neoplasms; Cell Movement; Cell Proliferation; Fatty Acids, Nonesterified; Female; Humans; Lung Neoplasms; Mice; Mice, Nude; Obesity; Phosphorylation; Signal Transduction; Smad4 Protein; Transforming Growth Factor beta; Tumor Cells, Cultured; Ubiquitin Thiolesterase; Ubiquitination

Obesity is a major health problem in modern society because their progression is always associated with many health issues. The major among them is developing the cardiovascular disease because as the obesity prolonged it results with cardiac remodelling and finally results in the dysfunction of the cardiac system. Many genes are associated with developing the obesity-linked cardiac dysfunction and it should be evaluated at different pathological stages of obesity.. In the present studies, we analyzed the expression pattern of Smad6 and TGF-β using obesity-induced mice model which are ob/ob-/- deficient. The pathology of disease progression in initial and aggressive stage of cardiac dysfunction are studied together with Smad6 and TGF-β expression.. The mice develop initial stages of cardiac dysfunction on 3rd month and advanced stage of cardiac dysfunction on the 6th month. The results with histology show as the dysfunction progress it shows cellular lesions associated with enlarged cells. Immunochemistry with Smad6 represents that its expression positively regulate and repair the initial lesion but it has no role in the aggressive form of cardiac dysfunction and at that stage their expression downregulated. The results with TGF-β show initial upregulation in repairing the damage but in latter stage its expression many fold increases and it takes part in the inflammatory response.. Overall our results show aberrant expression of Smad6 and TGF-β at different stages of obesity linked cardiac dysfunction.

Topics: Animals; Heart Diseases; Mice; Obesity; Signal Transduction; Smad6 Protein; Transforming Growth Factor beta

Topics: AMP-Activated Protein Kinases; Animals; Apoptosis; Biomarkers; Gene Expression Regulation; Hydrogen Peroxide; Intracellular Signaling Peptides and Proteins; MAP Kinase Kinase Kinase 5; Mice; Models, Biological; Nuclear Proteins; Obesity; Oxidation-Reduction; p38 Mitogen-Activated Protein Kinases; Phosphoproteins; Phosphorylation; Protein Binding; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-jun; Signal Transduction; Transcription, Genetic; Transforming Growth Factor beta; Tumor Suppressor Protein p53

To explore the molecular connections between redox-dependent apoptosis signal-regulating kinase 1 (ASK1) and transforming growth factor-β (TGF-β) signaling pathways and to examine the physiological processes in which coordinated regulation of these two signaling pathways plays a critical role.. We provide evidence that the ASK1 and TGF-β signaling pathways are interconnected by a multiprotein complex harboring murine protein serine-threonine kinase 38 (MPK38), ASK1, Sma- and Mad-related proteins (SMADs), zinc-finger-like protein 9 (ZPR9), and thioredoxin (TRX) and demonstrate that the activation of either ASK1 or TGF-β activity is sufficient to activate both the redox-dependent ASK1 and TGF-β signaling pathways. Physiologically, the restoration of the downregulated activation levels of ASK1 and TGF-β signaling in genetically and diet-induced obese mice by adenoviral delivery of SMAD3 or ZPR9 results in the amelioration of adiposity, hyperglycemia, hyperlipidemia, and impaired ketogenesis.. Our data suggest that the multiprotein complex linking ASK1 and TGF-β signaling pathways may be a potential target for redox-mediated metabolic complications.

Topics: Animals; Cell Line; Gene Expression Regulation; Glucose; Humans; Lipid Metabolism; MAP Kinase Kinase Kinase 5; Mice; Multiprotein Complexes; Obesity; Oxidation-Reduction; Phosphorylation; Protein Binding; Signal Transduction; Transforming Growth Factor beta

The purpose of the study was to develop a novel diet based on standard AIN93G diet that would be able to induce experimental obesity and impair immune regulation with high concentrations of both carbohydrate and lipids.. To compare the effects of this high sugar and butter (HSB) diet with other modified diets, male C57BL/6 mice were fed either mouse chow, or AIN93G diet, or high sugar (HS) diet, or high-fat (HF) diet, or high sugar and butter (HSB) diet for 11 weeks ad libitum. HSB diet induced higher weight gain. Therefore, control AIN93G and HSB groups were chosen for additional analysis. Regulatory T cells were studied by flow cytometry, and cytokine levels were measured by ELISA.. Although HF and HSB diets were able to induce a higher weight gain compatible with obesity in treated mice, HSB-fed mice presented the higher levels of serum glucose after fasting and the lowest frequency of regulatory T cells in adipose tissue. In addition, mice that were fed HSB diet presented higher levels of cholesterol and triglycerides, hyperleptinemia, increased resistin and leptin levels as well as reduced adiponectin serum levels. Importantly, we found increased frequency of CD4(+)CD44(+) effector T cells, reduction of CD4(+)CD25(+)Foxp3(+) and Th3 regulatory T cells as well as decreased levels of IL-10 and TGF-β in adipose tissue of HSB-fed mice.. Therefore, HSB represents a novel model of obesity-inducing diet that was efficient in triggering alterations compatible with metabolic syndrome as well as impairment in immune regulatory parameters.

Topics: Adipokines; Adipose Tissue; Animals; Blood Glucose; Cholesterol; Diet, High-Fat; Dietary Carbohydrates; Dietary Fats; Interleukin-10; Male; Metabolic Syndrome; Mice, Transgenic; Obesity; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Triglycerides

nonalcoholic fatty liver disease (NAFLD), an obesity and insulin resistance associated clinical condition - ranges from simple steatosis to nonalcoholic steatohepatitis. To model the human condition, a high-fat Western diet that includes liquid sugar consumption has been used in mice. Even though liver pathophysiology has been well characterized in the model, little is known about the metabolic phenotype (e.g., energy expenditure, activity, or food intake). Furthermore, whether the consumption of liquid sugar exacerbates the development of glucose intolerance, insulin resistance, and adipose tissue dysfunction in the model is currently in question. In our study, a high-fat Western diet (HFWD) with liquid sugar [fructose and sucrose (F/S)] induced acute hyperphagia above that observed in HFWD-fed mice, yet without changes in energy expenditure. Liquid sugar (F/S) exacerbated HFWD-induced glucose intolerance and insulin resistance and impaired the storage capacity of epididymal white adipose tissue (eWAT). Hepatic TG, plasma alanine aminotransferase, and normalized liver weight were significantly increased only in HFWD+F/S-fed mice. HFWD+F/S also resulted in increased hepatic fibrosis and elevated collagen 1a2, collagen 3a1, and TGFβ gene expression. Furthermore, HWFD+F/S-fed mice developed more profound eWAT inflammation characterized by adipocyte hypertrophy, macrophage infiltration, a dramatic increase in crown-like structures, and upregulated proinflammatory gene expression. An early hypoxia response in the eWAT led to reduced vascularization and increased fibrosis gene expression in the HFWD+F/S-fed mice. Our results demonstrate that sugary water consumption induces acute hyperphagia, limits adipose tissue expansion, and exacerbates glucose intolerance and insulin resistance, which are associated with NAFLD progression.

Topics: Adipocytes, White; Adipose Tissue, White; Alanine Transaminase; Animals; Collagen Type I; Collagen Type III; Diet, High-Fat; Diet, Western; Dietary Sucrose; Disease Models, Animal; Fibrosis; Fructose; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hyperphagia; Immunoblotting; Insulin Resistance; Liver; Macrophages; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Organ Size; Phenotype; Proto-Oncogene Proteins c-akt; Transcriptome; Transforming Growth Factor beta; Triglycerides

Phosphatidylethanolamine N-methyltransferase (PEMT) is an important enzyme in hepatic phosphatidylcholine (PC) biosynthesis. Pemt(-/-) mice are protected against high-fat diet (HFD)-induced obesity and insulin resistance; however, these mice develop nonalcoholic fatty liver disease (NAFLD). We hypothesized that peroxisomal proliferator-activated receptor-γ (PPARγ) activation by pioglitazone might stimulate adipocyte proliferation, thereby directing lipids from the liver toward white adipose tissue. Pioglitazone might also act directly on PPARγ in the liver to improve NAFLD. Pemt(+/+) and Pemt(-/-) mice were fed a HFD with or without pioglitazone (20 mg·kg(-1)·day(-1)) for 10 wk. Pemt(-/-) mice were protected from HFD-induced obesity but developed NAFLD. Treatment with pioglitazone caused an increase in body weight gain in Pemt(-/-) mice that was mainly due to increased adiposity. Moreover, pioglitazone improved NAFLD in Pemt(-/-) mice, as indicated by a 35% reduction in liver weight and a 57% decrease in plasma alanine transaminase levels. Livers from HFD-fed Pemt(-/-) mice were steatotic, inflamed, and fibrotic. Hepatic steatosis was still evident in pioglitazone-treated Pemt(-/-) mice; however, treatment with pioglitazone reduced hepatic fibrosis, as evidenced by reduced Sirius red staining and lowered mRNA levels of collagen type Iα1 (Col1a1), tissue inhibitor of metalloproteinases 1 (Timp1), α-smooth muscle actin (Acta2), and transforming growth factor-β (Tgf-β). Similarly, oxidative stress and inflammation were reduced in livers from Pemt(-/-) mice upon treatment with pioglitazone. Together, these data show that activation of PPARγ in HFD-fed Pemt(-/-) mice improved liver function, while these mice were still protected against diet-induced obesity and insulin resistance.

Topics: Actins; Adipocytes, White; Adipose Tissue, White; Adiposity; Animals; Anti-Infective Agents; Cell Proliferation; Collagen Type I; Collagen Type I, alpha 1 Chain; Diet, High-Fat; Genetic Predisposition to Disease; Hepatitis; Insulin Resistance; Liver; Liver Cirrhosis, Experimental; Mice, Inbred C57BL; Mice, Knockout; Non-alcoholic Fatty Liver Disease; Obesity; Oxidative Stress; Phenotype; Phosphatidylethanolamine N-Methyltransferase; Pioglitazone; PPAR gamma; Signal Transduction; Thiazolidinediones; Time Factors; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta

Obesity is an increasingly urgent global problem, yet, little is known about its causes and less is known how obesity can be effectively treated. We showed previously that the aryl hydrocarbon receptor (AHR) plays a role in the regulation of body mass in mice fed Western diet. The AHR is a ligand-activated nuclear receptor that regulates genes involved in a number of biological pathways, including xenobiotic metabolism and T cell polarization. This study was an investigation into whether inhibition of the AHR prevents Western diet-based obesity. Male C57Bl/6J mice were fed control and Western diets with and without the AHR antagonist α-naphthoflavone or CH-223191, and a mouse hepatocyte cell line was used to delineate relevant cellular pathways. Studies are presented showing that the AHR antagonists α-naphthoflavone and CH-223191 significantly reduce obesity and adiposity and ameliorates liver steatosis in male C57Bl/6J mice fed a Western diet. Mice deficient in the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) were also resistant to obesity. Using an AHR-directed, luciferase-expressing mouse hepatocyte cell line, we show that the transforming growth factor β1 (TGFβ1) signaling pathway via PI3K and NF-κB and the toll-like receptor 2/4 (TLR2/4) signaling pathway stimulated by oxidized low-density lipoproteins via NF-κB, each induce luciferase expression; however, TLR2/4 signaling was significantly reduced by inhibition of IDO1. At physiological levels, kynurenine but not kynurenic acid (both tryptophan metabolites and known AHR agonists) activated AHR-directed luciferase expression. We propose a hepatocyte-based model, in which kynurenine production is increased by enhanced IDO1 activity stimulated by TGFβ1 and TLR2/4 signaling, via PI3K and NF-κB, to perpetuate a cycle of AHR activation to cause obesity; and inhibition of the AHR, in turn, blocks the cycle's output to prevent obesity. The AHR with its broad ligand binding specificity is a promising candidate for a potentially simple therapeutic approach for the prevention and treatment of obesity and associated complications.

Topics: Adiposity; Animals; Azo Compounds; Benzoflavones; Diet, Western; Fatty Liver; Hepatocytes; Indoleamine-Pyrrole 2,3,-Dioxygenase; Intra-Abdominal Fat; Kynurenine; Lipids; Lipoproteins, LDL; Male; Mice; Mice, Inbred C57BL; Obesity; Pyrazoles; Receptors, Aryl Hydrocarbon; Signal Transduction; Toll-Like Receptor 2; Transforming Growth Factor beta

Obesity induces white adipose tissue (WAT) dysfunction characterized by unremitting inflammation and fibrosis, impaired adaptive thermogenesis and increased lipolysis. Prostaglandins (PGs) are powerful lipid mediators that influence the homeostasis of several organs and tissues. The aim of the current study was to explore the regulatory actions of PGs in human omental WAT collected from obese patients undergoing laparoscopic bariatric surgery. In addition to adipocyte hypertrophy, obese WAT showed remarkable inflammation and total and pericellular fibrosis. In this tissue, a unique molecular signature characterized by altered expression of genes involved in inflammation, fibrosis and WAT browning was identified by microarray analysis. Targeted LC-MS/MS lipidomic analysis identified increased PGE2 levels in obese fat in the context of a remarkable COX-2 induction and in the absence of changes in the expression of terminal prostaglandin E synthases (i.e. mPGES-1, mPGES-2 and cPGES). IPA analysis established PGE2 as a common top regulator of the fibrogenic/inflammatory process present in this tissue. Exogenous addition of PGE2 significantly reduced the expression of fibrogenic genes in human WAT explants and significantly down-regulated Col1α1, Col1α2 and αSMA in differentiated 3T3 adipocytes exposed to TGF-β. In addition, PGE2 inhibited the expression of inflammatory genes (i.e. IL-6 and MCP-1) in WAT explants as well as in adipocytes challenged with LPS. PGE2 anti-inflammatory actions were confirmed by microarray analysis of human pre-adipocytes incubated with this prostanoid. Moreover, PGE2 induced expression of brown markers (UCP1 and PRDM16) in WAT and adipocytes, but not in pre-adipocytes, suggesting that PGE2 might induce the trans-differentiation of adipocytes towards beige/brite cells. Finally, PGE2 inhibited isoproterenol-induced adipocyte lipolysis. Taken together, these findings identify PGE2 as a regulator of the complex network of interactions driving uncontrolled inflammation and fibrosis and impaired adaptive thermogenesis and lipolysis in human obese visceral WAT.

Topics: Adipocytes; Adipogenesis; Adipose Tissue, White; Cell Differentiation; Cyclooxygenase 2; Dinoprostone; Down-Regulation; Homeostasis; Humans; Inflammation; Interleukin-6; Lipolysis; Obesity; Signal Transduction; Thermogenesis; Transforming Growth Factor beta

Hyperglycemia, hyperlipidemia, and insulin resistance are hallmarks of obesity-induced type 2 diabetes, which is often caused by a high-fat diet (HFD). However, the molecular mechanisms underlying HFD-induced insulin resistance have not been elucidated in detail. In this study, we established a Drosophila model to investigate the molecular mechanisms of HFD-induced diabetes. HFD model flies recapitulate mammalian diabetic phenotypes including elevated triglyceride and circulating glucose levels, as well as insulin resistance. Expression of glass bottom boat (gbb), a Drosophila homolog of mammalian transforming growth factor-β (TGF-β), is elevated under HFD conditions. Furthermore, overexpression of gbb in the fat body produced obese and insulin-resistant phenotypes similar to those of HFD-fed flies, whereas inhibition of Gbb signaling significantly ameliorated HFD-induced metabolic phenotypes. We also discovered that tribbles, a negative regulator of AKT, is a target gene of Gbb signaling in the fat body. Overexpression of tribbles in flies in the fat body phenocopied the metabolic defects associated with HFD conditions or Gbb overexpression, whereas tribbles knockdown rescued these metabolic phenotypes. These results indicate that HFD-induced TGF-β/Gbb signaling provokes insulin resistance by increasing tribbles expression.

Topics: Animals; Cell Cycle Proteins; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Drosophila Proteins; Fat Body; Gene Expression Regulation; Humans; Insulin Resistance; Male; Obesity; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; Transforming Growth Factor beta

First line treatment for recurrent and metastatic prostate cancer is androgen deprivation therapy (ADT). Use of ADT has been increasing in frequency and duration, such that side effects increasingly impact patient quality of life. One of the most significant side effects of ADT is sarcopenia, which leads to a loss of skeletal muscle mass and function, resulting in a clinical disability syndrome known as obese frailty. Using aged mice, we developed a mouse model of ADT-induced sarcopenia that closely resembles the phenotype seen in patients, including loss of skeletal muscle strength, reduced lean muscle mass, and increased adipose tissue. Sarcopenia onset occurred about 6 weeks after castration and was blocked by a soluble receptor (ActRIIB-Fc) that binds multiple TGFβ superfamily members, including myostatin, growth differentiation factor 11, activin A, activin B, and activin AB. Analysis of ligand expression in both gastrocnemius and triceps brachii muscles demonstrates that each of these proteins is induced in response to ADT, in 1 of 3 temporal patterns. Specifically, activin A and activin AB levels increase and decline before onset of strength loss at 6 weeks after castration, and myostatin levels increase coincident with the onset of strength loss and then decline. In contrast, activin B and growth differentiation factor 11 levels increase after the onset of strength loss, 8-10 weeks after castration. The observed patterns of ligand induction may represent differential contributions to the development and/or maintenance of sarcopenia. We hypothesize that some or all of these ligands are targets for therapy to ameliorate ADT-induced sarcopenia in prostate cancer patients.

Topics: Activin Receptors, Type II; Activins; Animals; Bone Morphogenetic Proteins; Castration; Growth Differentiation Factors; Male; Mice; Mice, Inbred C57BL; Muscle Strength; Myostatin; Obesity; Sarcopenia; Transforming Growth Factor beta

The levels of the hormone prolactin (PRL) are reduced in the circulation of patients with Type 2 diabetes and in obese children, and lower systemic PRL levels correlate with an increased prevalence of diabetes and a higher risk of metabolic syndrome. The secretion of anterior pituitary (AP) PRL in metabolic diseases may be influenced by the interplay between transforming growth factor β (TGF-β) and tumor necrosis factor α (TNF-α), which inhibit and can stimulate AP PRL synthesis, respectively, and are known contributors to insulin resistance and metabolic complications. Here, we show that TGF-β and TNF-α antagonize the effect of each other on the expression and release of PRL by the GH4C1 lactotrope cell line. The levels of AP mRNA and circulating PRL decrease in high-fat diet-induced obese rats in parallel with increased and reduced AP levels of TGF-β and TNF-α mRNA, respectively. Likewise, AP expression and circulating levels of PRL are reduced in streptozotocin-induced diabetic rats and are associated with higher AP expression and protein levels of TGF-β and TNF-α. The opposing effects of the two cytokines on cultured AP cells, together with their altered expression in the AP of obese and diabetic rats suggest they are linked to the reduced PRL production and secretion characteristics of metabolic diseases.

Topics: Animals; Blood Glucose; Cell Line, Tumor; Diabetes Mellitus, Experimental; Gene Expression Regulation; Male; Obesity; Pituitary Gland, Anterior; Prolactin; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

The development of breast cancer is linked to the loss of estrogen receptor (ER) during the course of tumor progression, resulting in loss of responsiveness to hormonal treatment. The mechanisms underlying dynamic ERα gene expression change in breast cancer remain unclear. A range of physiological and biological changes, including increased adipose tissue hypoxia, accompanies obesity. Hypoxia in adipocytes can establish a pro-malignancy environment in breast tissues. Epidemiological studies have linked obesity with basal-like breast cancer risk and poor disease outcome, suggesting that obesity may affect the tumor phenotype by skewing the microenvironment toward support of more aggressive tumor phenotypes. In the present study, human SGBS adipocytes were co-cultured with ER-positive MCF7 cells for 24 h. After co-culture, HIF1α, TGF-β, and lectin-type oxidized LDL receptor 1 (LOX1) mRNA levels in the SGBS cells were increased. Expression levels of the epithelial-mesenchymal transition (EMT)-inducing transcription factors FOXC2 and TWIST1 were increased in the co-cultured MCF7 cells. In addition, the E-cadherin mRNA level was decreased, while the N-cadherin mRNA level was increased in the co-cultured MCF7 cells. ERα mRNA levels were significantly repressed in the co-cultured MCF7 cells. ERα gene expression in the MCF7 cells was decreased due to increased HIF1α in the SGBS cells. These results suggest that adipocytes can modify breast cancer cell ER gene expression through hypoxia and also can promote EMT processes in breast cancer cells, supporting an important role of obesity in aggressive breast cancer development.

Topics: Adipocytes; Breast Neoplasms; Cell Hypoxia; Cell Proliferation; Coculture Techniques; Epithelial-Mesenchymal Transition; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; MCF-7 Cells; Nuclear Proteins; Obesity; Scavenger Receptors, Class E; Transforming Growth Factor beta; Tumor Microenvironment; Twist-Related Protein 1

Heart failure in diabetics is associated with cardiac hypertrophy, fibrosis and diastolic dysfunction. Activation of transforming growth factor-β/Smad3 signaling in the diabetic myocardium may mediate fibrosis and diastolic heart failure, while preserving matrix homeostasis. We hypothesized that Smad3 may play a key role in the pathogenesis of cardiovascular remodeling associated with diabetes mellitus and obesity.. We generated leptin-resistant db/db Smad3 null mice and db/db Smad3+/- animals. Smad3 haploinsufficiency did not affect metabolic function in db/db mice, but protected from myocardial diastolic dysfunction, while causing left ventricular chamber dilation. Improved cardiac compliance and chamber dilation in db/db Smad3+/- animals were associated with decreased cardiomyocyte hypertrophy, reduced collagen deposition, and accentuated matrix metalloproteinase activity. Attenuation of hypertrophy and fibrosis in db/db Smad3+/- hearts was associated with reduced myocardial oxidative and nitrosative stress. db/db Smad3 null mice had reduced weight gain and decreased adiposity associated with attenuated insulin resistance, but also exhibited high early mortality, in part, because of spontaneous rupture of the ascending aorta. Ultrasound studies showed that both lean and obese Smad3 null animals had significant aortic dilation. Aortic dilation in db/db Smad3 null mice occurred despite reduced hypertension and was associated with perturbed matrix balance in the vascular wall.. Smad3 mediates diabetic cardiac hypertrophy, fibrosis, and diastolic dysfunction, while preserving normal cardiac geometry and maintaining the integrity of the vascular wall.

Topics: Animals; Aorta; Aortic Aneurysm; Aortic Rupture; Cardiomegaly; Diabetic Cardiomyopathies; Dilatation, Pathologic; Disease Models, Animal; Female; Fibrosis; Male; Matrix Metalloproteinases; Mice, Inbred C57BL; Mice, Knockout; Myocardium; Obesity; Signal Transduction; Smad3 Protein; Time Factors; Transforming Growth Factor beta; Vascular Remodeling; Ventricular Dysfunction, Left; Ventricular Remodeling

To investigate the effects of bariatric surgery on metabolic parameters, incretin hormone secretion, and duodenal and ileal mucosal gene expression.. Nine patients with type 2 diabetes mellitus (T2DM), chronic serum hyperglycemia for more than 2 years, and a body mass index (BMI) of 30-35 kg/m(2) underwent metabolic surgery sleeve gastrectomy with transit bipartition between May 2011 and December 2011. Blood samples were collected pre and 3, 6 and 12 mo postsurgery. Duodenal and ileal mucosa samples were collected pre- and 3 mo postsurgery. Pre- and postoperative blood samples were collected in the fasting state before ingestion of a standard meal (520 kcal) and again 30, 60, 90, and 120 min after the meal to determine hemoglobin A1c (HbA1c) levels and the lipid profile, which consisted of triglyceride and total cholesterol levels. Intestinal gene expression of p53 and transforming growth factor (TGF)-β was analyzed using quantitative reverse-transcription PCR. Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were quantified using the enzyme-linked immunoassay method and analyzed pre- and postoperatively. Student's t test or repeated measurements analysis of variance with Bonferroni corrections were performed as appropriate.. BMI values decreased by 15.7% within the initial 3 mo after surgery (31.29 ± 0.73 vs 26.398 ± 0.68, P < 0.05) and then stabilized at 22% at 6 mo postoperative, resulting in similar values 12 mo postoperatively (20-25 kg/m(2)). All of the patients experienced improved T2DM, with 7 patients (78%) achieving complete remission (HbA1c < 6.5%), and 2 patients (22%) achieving improved diabetes (HbA1c < 7.0% with or without the use of oral hypoglycemic agents). At 3 mo postoperatively, fasting plasma glucose had also decreased (59%) (269.55 ± 18.24 mg/dL vs 100.77 ± 3.13 mg/dL, P < 0.05) with no further significant changes at 6 or 12 mo postoperatively. In the first month postoperatively, there was a complete withdrawal of hypoglycemic medications in all patients, who were taking at least 2 hypoglycemic drugs preoperatively. GLP-1 levels significantly increased after surgery (149.96 ± 31.25 vs 220.23 ± 27.55) (P < 0.05), while GIP levels decreased but not significantly. p53 gene expression significantly increased in the duodenal mucosa (P < 0.05, 2.06 fold) whereas the tumor growth factor-β gene expression significantly increased (P < 0.05, 2.52 fold) in the ileal mucosa after surgery.. Metabolic surgery ameliorated diabetes in all of the patients, accompanied by increased anti-proliferative intestinal gene expression in non-excluded segments of the intestine.

Topics: Adult; Bariatric Surgery; Biomarkers; Biopsy; Blood Glucose; Body Mass Index; Cell Proliferation; Diabetes Mellitus, Type 2; Duodenum; Fasting; Female; Gastrectomy; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Ileum; Intestinal Mucosa; Male; Middle Aged; Obesity; Postprandial Period; Remission Induction; Time Factors; Transforming Growth Factor beta; Treatment Outcome; Tumor Suppressor Protein p53; Weight Loss

Increased central vascular stiffening, assessed in vivo by determination of pulse wave velocity (PWV), is an independent predictor of cardiovascular event risk. Recent evidence demonstrates that accelerated aortic stiffening occurs in obesity; however, little is known regarding stiffening of other disease-relevant arteries or whether regional variation in arterial stiffening occurs in this setting. We addressed this gap in knowledge by assessing femoral PWV in vivo in conjunction with ex vivo analyses of femoral and coronary structure and function in a mouse model of Western diet (WD; high-fat/high-sugar)-induced obesity and insulin resistance. WD feeding resulted in increased femoral PWV in vivo. Ex vivo analysis of femoral arteries revealed a leftward shift in the strain-stress relationship, increased modulus of elasticity, and decreased compliance indicative of increased stiffness following WD feeding. Confocal and multiphoton fluorescence microscopy revealed increased femoral stiffness involving decreased elastin/collagen ratio in conjunction with increased femoral transforming growth factor-β (TGF-β) content in WD-fed mice. Further analysis of the femoral internal elastic lamina (IEL) revealed a significant reduction in the number and size of fenestrae with WD feeding. Coronary artery stiffness and structure was unchanged by WD feeding. Functionally, femoral, but not coronary, arteries exhibited endothelial dysfunction, whereas coronary arteries exhibited increased vasoconstrictor responsiveness not present in femoral arteries. Taken together, our data highlight important regional variations in the development of arterial stiffness and dysfunction associated with WD feeding. Furthermore, our results suggest TGF-β signaling and IEL fenestrae remodeling as potential contributors to femoral artery stiffening in obesity.

Topics: Animals; Collagen; Coronary Vessels; Diet, High-Fat; Elastin; Femoral Artery; Male; Mice; Mice, Inbred C57BL; Obesity; Organ Specificity; Transforming Growth Factor beta; Vascular Stiffness

Mechanisms of restenosis in type 2 diabetes mellitus (T2DM) are incompletely elucidated, but advanced glycation end-product (AGE)-induced vascular remodeling likely contributes. We tested the hypothesis that AGE-related collagen cross-linking (ARCC) leads to increased downstream vascular resistance and altered in-stent hemodynamics, thereby promoting neointimal hyperplasia (NH) in T2DM. We proposed that decreasing ARCC with ALT-711 (Alagebrium) would mitigate this response. Abdominal aortic stents were implanted in Zucker lean (ZL), obese (ZO), and diabetic (ZD) rats. Blood flow, vessel diameter, and wall shear stress (WSS) were calculated after 21 days, and NH was quantified. Arterial segments (aorta, carotid, iliac, femoral, and arterioles) were harvested to detect ARCC and protein expression, including transforming growth factor-β (TGF-β) and receptor for AGEs (RAGE). Downstream resistance was elevated (60%), whereas flow and WSS were significantly decreased (44% and 56%) in ZD vs. ZL rats. NH was increased in ZO but not ZD rats. ALT-711 reduced ARCC and resistance (46%) in ZD rats while decreasing NH and producing similar in-stent WSS across groups. No consistent differences in RAGE or TGF-β expression were observed in arterial segments. ALT-711 modified lectin-type oxidized LDL receptor 1 but not RAGE expression by cells on decellularized matrices. In conclusion, ALT-711 decreased ARCC, increased in-stent flow rate, and reduced NH in ZO and ZD rats through RAGE-independent pathways. The study supports an important role for AGE-induced remodeling within and downstream of stent implantation to promote enhanced NH in T2DM.

Topics: Animals; Aorta, Abdominal; Collagen; Diabetes Mellitus; Glycation End Products, Advanced; Graft Occlusion, Vascular; Male; Neointima; Obesity; Rats; Rats, Zucker; Receptor for Advanced Glycation End Products; Shear Strength; Stents; Stress, Mechanical; Thiazoles; Transforming Growth Factor beta; Vascular Resistance

Obesity is one of the major risk factors for nonalcoholic fatty liver disease (NAFLD), and NAFLD is highly associated with an increased risk of cardiovascular disease (CVD). Scholars have suggested that certain probiotics may significantly impact cardiovascular health, particularly certain Lactobacillus species, such as Lactobacillus reuteri GMNL-263 (Lr263) probiotics, which have been shown to reduce obesity and arteriosclerosis in vivo. In the present study, we examined the potential of heat-killed bacteria to attenuate high fat diet (HFD)-induced hepatic and cardiac damages and the possible underlying mechanism of the positive effects of heat-killed Lr263 oral supplements. Heat-killed Lr263 treatments (625 and 3125 mg/kg-hamster/day) were provided as a daily supplement by oral gavage to HFD-fed hamsters for eight weeks. The results show that heat-killed Lr263 treatments reduce fatty liver syndrome. Moreover, heat-killed Lactobacillus reuteri GMNL-263 supplementation in HFD hamsters also reduced fibrosis in the liver and heart by reducing transforming growth factor β (TGF-β) expression levels. In conclusion, heat-killed Lr263 can reduce lipid metabolic stress in HFD hamsters and decrease the risk of fatty liver and cardiovascular disease.

Topics: Animals; Cricetinae; Diet, High-Fat; Fatty Liver; Fibrosis; Heart Diseases; Limosilactobacillus reuteri; Male; Obesity; Probiotics; Transforming Growth Factor beta

The NLRP3 inflammasome plays an important regulatory role in obesity-induced insulin resistance. NSAID activated gene-1 (NAG-1) is a divergent member of the TGF-β superfamily. NAG-1 Tg mice are resistant to dietary- and genetic-induced obesity and have improved insulin sensitivity. The objective was to examine whether NLRP3 inflammasome activity is associated with this observed phenotype in NAG-1 Tg mice.. Key components of the NLRP3 inflammasome were examined in NAG-1 Tg mice on both regular and high fat diet (HFD) conditions.. The expression of caspase-1 and ASC, key components of the NLRP3 inflammasome, is significantly reduced at mRNA and protein levels in white adipose tissue (WAT) of NAG-1 Tg mice. HFD increases the expression of caspase-1 and ASC in WT mice, but their expression is reduced in NAG-1 Tg mice. Furthermore, there is reduced IL-18, IL-1β, and TNF-α expression in the WAT of NAG-1 Tg mice. NAG-1 Tg mice have significantly lower serum leptin and insulin levels and reduced expression of macrophage infiltration markers (F4/80, CD11b, and CD11c) in WAT.. The study suggests the lower NLRP3 inflammasome activity may play a role in the resistance of NAG-1 Tg mice to diet-induced obesity and improved insulin sensitivity.

Topics: Adipose Tissue, White; Animals; Carrier Proteins; Caspase 1; CD11b Antigen; CD11c Antigen; Diet, High-Fat; Female; Inflammasomes; Insulin; Insulin Resistance; Interleukin-18; Interleukin-1beta; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; NLR Family, Pyrin Domain-Containing 3 Protein; Obesity; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Chronic inflammation is known to promote metabolic dysregulation in obesity and type 2 diabetes. Although the precise origin of the unchecked inflammatory response in obesity is unclear, it is known that overproduction of proinflammatory cytokines by innate immune cells affects metabolism. For example, TNF-α contributes to the inability of cells to respond to insulin and to the increase in levels of insulin. Whether this hyperinsulinemia itself is part of a feedback loop that affects the progression of chronic adipose inflammation is unknown. In this article, we show that regulatory T cells (Tregs) express the insulin receptor, and that high levels of insulin impair the ability of Tregs to suppress inflammatory responses via effects on the AKT/mTOR signaling pathway. Insulin activated AKT signaling in Tregs, leading to inhibition of both IL-10 production and the ability of Tregs to suppress the production of TNF-α by macrophages in a contact-independent manner. The effect of insulin on Treg suppression was limited to IL-10 production and it did not alter the expression of other proteins associated with Treg function, including CTLA-4, CD39, and TGF-β. In a model of diet-induced obesity, Tregs from the visceral adipose tissue of hyperinsulinemic, obese mice showed a similar specific decrease in IL-10 production, as well as a parallel increase in production of IFN-γ. These data suggest that hyperinsulinemia may contribute to the development of obesity-associated inflammation via a previously unknown effect of insulin on the IL-10-mediated function of Tregs.

Topics: Animals; Antigens, CD; Apyrase; Cells, Cultured; CTLA-4 Antigen; Epithelial Cells; Epithelium; Hyperinsulinism; Inflammation; Insulin; Interferon-gamma; Interleukin-10; Intra-Abdominal Fat; Macrophages; Mice; Mice, Inbred C57BL; Obesity; Proto-Oncogene Proteins c-akt; Receptor, Insulin; Signal Transduction; T-Lymphocytes, Regulatory; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Microfibril-associated glycoprotein 1 (MAGP1) is a component of extracellular matrix microfibrils. Here we show that MAGP1 expression is significantly altered in obese humans, and inactivation of the MAGP1 gene (Mfap2(-/-)) in mice results in adipocyte hypertrophy and predisposition to metabolic dysfunction. Impaired thermoregulation was evident in Mfap2(-/-) mice prior to changes in adiposity, suggesting a causative role for MAGP1 in the increased adiposity and predisposition to diabetes. By 5 weeks of age, Mfap2(-/-) mice were maladaptive to cold challenge, uncoupling protein-1 expression was attenuated in the brown adipose tissue, and there was reduced browning of the subcutaneous white adipose tissue. Levels of transforming growth factor-β (TGF-β) activity were elevated in Mfap2(-/-) adipose tissue, and the treatment of Mfap2(-/-) mice with a TGF-β-neutralizing antibody improved their body temperature and prevented the increased adiposity phenotype. Together, these findings indicate that the regulation of TGF-β by MAGP1 is protective against the effects of metabolic stress, and its absence predisposes individuals to metabolic dysfunction.

Topics: Adipocytes; Adipose Tissue; Animals; Contractile Proteins; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Genetic Pleiotropy; Genetic Predisposition to Disease; Male; Mice; Mice, Inbred C57BL; Obesity; Phenotype; RNA Splicing Factors; Signal Transduction; Thermogenesis; Transforming Growth Factor beta

We recently identified endotrophin as an adipokine with potent tumour-promoting effects. However, the direct effects of local accumulation of endotrophin in adipose tissue have not yet been studied. Here we use a doxycycline-inducible adipocyte-specific endotrophin overexpression model to demonstrate that endotrophin plays a pivotal role in shaping a metabolically unfavourable microenvironment in adipose tissue during consumption of a high-fat diet (HFD). Endotrophin serves as a powerful co-stimulator of pathologically relevant pathways within the 'unhealthy' adipose tissue milieu, triggering fibrosis and inflammation and ultimately leading to enhanced insulin resistance. We further demonstrate that blocking endotrophin with a neutralizing antibody ameliorates metabolically adverse effects and effectively reverses metabolic dysfunction induced during HFD exposure. Collectively, our findings demonstrate that endotrophin exerts a major influence in adipose tissue, eventually resulting in systemic elevation of pro-inflammatory cytokines and insulin resistance, and the results establish endotrophin as a potential target in the context of metabolism and cancer.

Topics: Adipocytes; Adipose Tissue; Adult; Animals; Collagen Type VI; Diabetes Mellitus; Diet, High-Fat; Energy Metabolism; Female; Fibrosis; Gene Expression; Humans; Inflammation; Insulin Resistance; Male; Matrix Metalloproteinase 12; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Confocal; Middle Aged; Obesity; Peptide Fragments; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta

The increasing frequency of obesity is important because of its accompanying related health problems. The effects of obesity on peripheral nerves have not been elucidated. We investigated the effects of obesity on sciatic nerve regeneration using electrophysiology, stereology, immunohistochemistry, histopathology and functional tests. We used control, obese, control injured and obese injured groups of rats. Electrophysiological results showed that nerve conduction velocity and EMG were same in the experimental groups, but the amplitude of the compound action potential of the control group was significantly higher than that of the obese group. Examination of the nerves showed that the control and obese groups had both larger axon diameters and thicker myelin sheaths. The number of myelinated axons was decreased in both of the injured groups. Axon diameters and myelin sheath thicknesses of the control injured group were significantly greater those of the obese injured group. There were no significant differences in functional tests among the groups. Although growth associated protein 43 immunostaining in the control injured group was significantly greater than that of the obese injured group, no significant difference was observed between the control and obese groups. There was no significant difference in immunohistochemical staining for transforming growth factor beta 3 between the control injured and obese injured groups. Our results suggest that obesity may affect peripheral nerve regeneration negatively after crush injury.

Topics: Animals; Axons; Diet, High-Fat; Female; GAP-43 Protein; Myelin Sheath; Nerve Regeneration; Obesity; Rats, Sprague-Dawley; Transforming Growth Factor beta

Topics: Adipocytes; Adipose Tissue; Animals; Contractile Proteins; Diabetes Mellitus, Type 2; Extracellular Matrix Proteins; Male; Obesity; RNA Splicing Factors; Transforming Growth Factor beta

The brain, in particular the hypothalamus, plays a role in regulating glucose homeostasis; however, it remains unclear whether this organ is causally and etiologically involved in the development of diabetes. Here, we found that hypothalamic transforming growth factor-β (TGF-β) production is excessive under conditions of not only obesity but also aging, which are two general etiological factors of type 2 diabetes. Pharmacological and genetic approaches revealed that central TGF-β excess caused hyperglycemia and glucose intolerance independent of a change in body weight. Further, using cell-specific genetic analyses in vivo, we found that astrocytes and proopiomelanocortin neurons are responsible for the production and prodiabetic effect of central TGF-β, respectively. Mechanistically, TGF-β excess induced a hypothalamic RNA stress response, resulting in accelerated mRNA decay of IκBα, an inhibitor of proinflammatory nuclear factor-κB. These results reveal an atypical, mRNA metabolism-driven hypothalamic nuclear factor-κB activation, a mechanism that links obesity as well as aging to hypothalamic inflammation and ultimately to type 2 diabetes.

Topics: Aging; Astrocytes; Diabetes Mellitus; Glucose Tolerance Test; Humans; Hypothalamus; NF-kappa B; Obesity; Pro-Opiomelanocortin; RNA; Stress, Physiological; Transforming Growth Factor beta

Topics: Aging; Diabetes Mellitus; Humans; Obesity; RNA; Stress, Physiological; Transforming Growth Factor beta

Obesity is associated with blunted β-adrenoreceptor (β-AR)-mediated lipolysis and lipid oxidation in adipose tissue, but the mechanisms linking nutrient overload to catecholamine resistance are poorly understood. We report that targeted disruption of TGF-β superfamily receptor ALK7 alleviates diet-induced catecholamine resistance in adipose tissue, thereby reducing obesity in mice. Global and fat-specific Alk7 knock-out enhanced adipose β-AR expression, β-adrenergic signaling, mitochondrial biogenesis, lipid oxidation, and lipolysis under a high fat diet, leading to elevated energy expenditure, decreased fat mass, and resistance to diet-induced obesity. Conversely, activation of ALK7 reduced β-AR-mediated signaling and lipolysis cell-autonomously in both mouse and human adipocytes. Acute inhibition of ALK7 in adult mice by a chemical-genetic approach reduced diet-induced weight gain, fat accumulation, and adipocyte size, and enhanced adipocyte lipolysis and β-adrenergic signaling. We propose that ALK7 signaling contributes to diet-induced catecholamine resistance in adipose tissue, and suggest that ALK7 inhibitors may have therapeutic value in human obesity.

Topics: Activin Receptors, Type I; Adenosine Triphosphate; Adipocytes; Adipose Tissue; Animals; Catecholamines; Diet, High-Fat; Dietary Fats; Gene Expression Regulation; Humans; Lipid Peroxidation; Lipolysis; Mice; Mice, Knockout; Mitochondrial Turnover; Obesity; Primary Cell Culture; Pyrazoles; Pyrimidines; Receptors, Adrenergic, beta; Signal Transduction; Transforming Growth Factor beta

Aging and a high-fat diet are predisposing factors for type 2 diabetes. A study in mice suggests that dietary fat and aging lead to atypical transforming growth factor-β1 signaling in the hypothalamus, which disturbs whole-body glucose regulation.

Topics: Aging; Diabetes Mellitus; Humans; Obesity; RNA; Stress, Physiological; Transforming Growth Factor beta

Rhus verniciflua Stokes (RVS) has been used as a traditional herbal medicine for its various biological activities including anti-adipogenic effects. Activity-guided separation led to the identification of the anti-adipogenic functions of butein. Butein, a novel anti-adipogenic compound, robustly suppressed lipid accumulation and inhibited expression of adipogenic markers. Molecular studies showed that activated transforming growth factor-β (TGF-β) and suppressed signal transducer and activator of transcription 3 (STAT3) signaling pathways were mediated by butein. Analysis of the temporal expression profiles suggests that TGF-β signaling precedes the STAT3 in the butein-mediated anti-adipogenic cascade. Small interfering RNA-mediated silencing of STAT3 or SMAD2/3 blunted the inhibitory effects of butein on adipogenesis indicating that an interaction between two signaling pathways is required for the action of butein. Upon butein treatments, stimulation of TGF-β signaling was still preserved in STAT3 silenced cells, whereas regulation of STAT3 signaling by butein was significantly impaired in SMAD2/3 silenced cells, further showing that TGF-β acts upstream of STAT3 in the butein-mediated anti-adipogenesis. Taken together, the present study shows that butein, a novel anti-adipogenic compound from RVS, inhibits adipocyte differentiation through the TGF-β pathway followed by STAT3 and peroxisome proliferator-activated receptor γ signaling, further implicating potential roles of butein in TGF-β- and STAT3-dysregulated diseases.

Topics: 3T3-L1 Cells; Adipose Tissue; Animals; Cell Differentiation; Cell Line; Chalcones; Gene Expression Regulation, Developmental; Mice; Mice, Knockout; Obesity; Phosphorylation; Rhus; Signal Transduction; Smad2 Protein; Smad3 Protein; STAT3 Transcription Factor; Transforming Growth Factor beta

The aim of the present study was to establish a progressive steatohepatitis mouse model because few reported animal models of non-alcoholic steatohepatitis (NASH) show the progression from fatty liver to steatohepatitis. C57BL/6N mice were fed a high-fat diet (HFD) to develop obesity and were either administered carbon tetrachloride (CCl4 ) eight times (0.05 mL/kg, s.c., once, followed by 0.1 mL/kg, s.c., seven times) or not. Serum parameters and hepatic histopathology were examined. In a separate experiment, CCl4 was administered subcutaneously from 0 to eight times to HFD-fed obese mice to investigate progressive changes. Markers of oxidative stress, inflammation and apoptosis, as well as histopathological changes in the liver, were analysed. The HFD-fed obese mice showed fatty liver but not steatohepatitis. In contrast, HFD-fed mice administered CCl4 eight times showed histopathological features of steatohepatitis (fatty liver, inflammation, hepatocellular ballooning and fibrosis) and increased serum alanine aminotransferase levels. However, the multiple administration of CCl4 to obese mice reduced the ratio of reduced glutathione to oxidized glutathione, superoxide dismutase activity and mitochondrial DNA copy number, leading to the development of chronic oxidative stress, increased numbers of apoptotic cells and increased levels of both tumour necrosis factor-α and transforming growth factor-β mRNA. The resulting inflammation led to increased hydroxyproline content in the liver and fibrosis. The present study demonstrates that multiple administration of CCl4 to HFD-fed obese mice induces chronic oxidative stress that triggers inflammation and apoptosis and leads to the development of fibrosis in the liver, resulting in progression from fatty liver to steatohepatitis. This murine model will be useful in the research of hepatic disorders.

Topics: Alanine Transaminase; Animals; Apoptosis; Carbon Tetrachloride; Diet, High-Fat; Disease Models, Animal; DNA Copy Number Variations; DNA, Mitochondrial; Fatty Liver; Fibrosis; Glutathione; Glutathione Disulfide; Inflammation; Liver; Liver Diseases; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Oxidative Stress; RNA, Messenger; Superoxide Dismutase; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Obesity results in reduced differentiation potential of adipocytes leading to adipose tissue insulin resistance. Elevated proinflammatory cytokines from adipose tissue in obesity, such as TNFα have been implicated in the reduced adipocyte differentiation. Other mediators of reduced adipocyte differentiation include TGFβ and wnt proteins. Although some overlap exists in the signaling cascades of the wnt and TGFβ pathways it is unknown if TGFβ or wnt proteins reciprocally induce the expression of each other to maximize their biological effects in adipocytes. Therefore, we investigated the possible involvement of TGFβ signaling in wnt induced gene expression and vice versa in 3T3-L1 adipocyte. Effect of TGFβ and Wnt pathways on differentiation was studied in preadipocytes induced to differentiate in the presence of Wnt3a or TGFβ1 and their inhibitors (FZ8-CRD and SB431542, respectively). Regulation of intracellular signaling and gene expression was also studied in mature adipocytes. Our results show that both TGFβ1 and Wnt3a lead to increased accumulation of β-catenin, phosphorylation of AKT and p44/42 MAPK. However, differences were found in the pattern of gene expression induced by the two proteins suggesting that distinct, but complex, signaling pathways are activated by TGFβ and wnt proteins to independently regulate adipocyte function.

Topics: 3T3-L1 Cells; Adipocytes; Animals; Benzamides; beta Catenin; Blotting, Western; Cell Differentiation; Dioxoles; DNA Primers; Gene Expression Profiling; Gene Expression Regulation; Mice; Obesity; Phosphorylation; Real-Time Polymerase Chain Reaction; Receptor Cross-Talk; RNA, Small Interfering; Transforming Growth Factor beta; Wnt Signaling Pathway

Obesity is prevalent worldwide and is a major risk factor for many diseases including renal complications. Thrombospondin 1 (TSP1), a multifunctional extracellular matrix protein, plays an important role in diabetic kidney diseases. However, whether TSP1 plays a role in obesity-related kidney disease is unknown. In the present studies, the role of TSP1 in obesity-induced renal dysfunction was determined by using a diet-induced obese mouse model. The results demonstrated that TSP1 was significantly upregulated in the kidney from obese mice. The increased TSP1 was localized in the glomerular mesangium as well as in the tubular system from obese wild-type mice. Obese wild-type mice developed renal hypertrophy and albuminuria, which was associated with increased kidney macrophage infiltration, augmented kidney inflammation, and activated transforming growth factor (TGF)-β signaling and renal fibrosis. In contrast, obese TSP1-deficient mice did not develop these kidney damages. Furthermore, in vitro studies demonstrated that leptin treatment stimulated the expression of TSP1, TGF-β1, fibronectin, and collagen type IV in mesangial cells isolated from wild-type mice. These leptin-stimulated effects were abolished in TSP1-deficient mesangial cells. Taken together, these data suggest that TSP1 is an important mediator for obesity- or hyperleptinemia-induced kidney dysfunction.

Topics: Animals; Cells, Cultured; Collagen Type IV; Diabetic Nephropathies; Diet, High-Fat; Disease Models, Animal; Fibronectins; Fibrosis; Kidney; Leptin; Male; Mice; Nephritis; Obesity; Thrombospondin 1; Transforming Growth Factor beta

Lipocalin 2 (Lcn2) has previously been characterized as an adipokine/cytokine playing a role in glucose and lipid homeostasis. In this study, we investigate the role of Lcn2 in adipose tissue remodeling during high-fat diet (HFD)-induced obesity. We find that Lcn2 protein is highly abundant selectively in inguinal adipose tissue. During 16 weeks of HFD feeding, the inguinal fat depot expanded continuously, whereas the expansion of the epididymal fat depot was reduced in both wild-type (WT) and Lcn2(-/-) mice. Interestingly, the depot-specific effect of HFD on fat mass was exacerbated and appeared more pronounced and faster in Lcn2(-/-) mice than in WT mice. In Lcn2(-/-) mice, adipocyte hypertrophy in both inguinal and epididymal adipose tissue was more profoundly induced by age and HFD when compared with WT mice. The expression of peroxisome proliferator-activated receptor-γ protein was significantly down-regulated, whereas the gene expression of extracellular matrix proteins was up-regulated selectively in epididymal adipocytes of Lcn2(-/-) mice. Consistent with these observations, collagen deposition was selectively higher in the epididymal, but not in the inguinal adipose depot of Lcn2(-/-) mice. Administration of the peroxisome proliferator-activated receptor-γ agonist rosiglitazone (Rosi) restored adipogenic gene expression. However, Lcn2 deficiency did not alter the responsiveness of adipose tissue to Rosi effects on the extracellular matrix expression. Rosi treatment led to the further enlargement of adipocytes with improved metabolic activity in Lcn2(-/-) mice, which may be associated with a more pronounced effect of Rosi treatment in reducing TGF-β in Lcn2(-/-) adipose tissue. Consistent with these in vivo observations, Lcn2 deficiency reduces the adipocyte differentiation capacity of stromal-vascular cells isolated from HFD-fed mice in these cells. Herein Rosi treatment was again able to stimulate adipocyte differentiation to a similar extent in WT and Lcn2(-/-) inguinal and epididymal stromal-vascular cells. Thus, combined, our data indicate that Lcn2 has a depot-specific role in HFD-induced adipose tissue remodeling.

Topics: Acute-Phase Proteins; Adipogenesis; Adipose Tissue, White; Adiposity; Age Factors; Animals; Cell Differentiation; Cells, Cultured; Diet, High-Fat; Extracellular Matrix Proteins; Gene Expression Regulation; Hypertrophy; Hypoglycemic Agents; Intra-Abdominal Fat; Lipocalin-2; Lipocalins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Oncogene Proteins; Specific Pathogen-Free Organisms; Stromal Cells; Transforming Growth Factor beta

Obesity is associated with atrial fibrillation (AF); however, the mechanisms by which it induces AF are unknown.. To examine the effect of progressive weight gain on the substrate for AF.. Thirty sheep were studied at baseline, 4 months, and 8 months, following a high-calorie diet. Ten sheep were sampled at each time point for cardiac magnetic resonance imaging and hemodynamic studies. High-density multisite biatrial epicardial mapping was used to quantify effective refractory period, conduction velocity, and conduction heterogeneity index at 4 pacing cycle lengths and AF inducibility. Histology was performed for atrial fibrosis, inflammation, and intramyocardial lipidosis, and molecular analysis was performed for endothelin-A and -B receptors, endothelin-1 peptide, platelet-derived growth factor, transforming growth factor β1, and connective tissue growth factor.. Increasing weight was associated with increasing left atrial volume (P = .01), fibrosis (P = .02), inflammatory infiltrates (P = .01), and lipidosis (P = .02). While there was no change in the effective refractory period (P = .2), there was a decrease in conduction velocity (P<.001), increase in conduction heterogeneity index (P<.001), and increase in inducible (P = .001) and spontaneous (P = .001) AF. There was an increase in atrial cardiomyocyte endothelin-A and -B receptors (P = .001) and endothelin-1 (P = .03) with an increase in adiposity. In association, there was a significant increase in atrial interstitial and cytoplasmic transforming growth factor β1 (P = .02) and platelet-derived growth factor (P = .02) levels.. Obesity is associated with atrial electrostructural remodeling. With progressive obesity, there were changes in atrial size, conduction, histology, and expression of profibrotic mediators. These changes were associated with spontaneous and more persistent AF.

Topics: Analysis of Variance; Animals; Atrial Fibrillation; Biomarkers; Blotting, Western; Connective Tissue Growth Factor; Disease Progression; Endothelin-1; Heart Atria; Heart Conduction System; Hemodynamics; Immunoenzyme Techniques; Magnetic Resonance Imaging; Obesity; Platelet-Derived Growth Factor; Receptor, Endothelin A; Receptor, Endothelin B; Refractory Period, Electrophysiological; Sheep; Statistics, Nonparametric; Transforming Growth Factor beta

Differentiation of adipocytes from preadipocytes contributes to adipose tissue expansion in obesity. Impaired adipogenesis may underlie the development of metabolic diseases such as insulin resistance and type 2 diabetes. Mechanistically, a well defined transcriptional network coordinates adipocyte differentiation. The family of paired-related homeobox transcription factors, which includes Prrx1a, Prrx1b, and Prrx2, is implicated with regulation of mesenchymal cell fate, including myogenesis and skeletogenesis; however, whether these proteins impact adipogenesis remains to be addressed. In this study, we identify Prrx1a and Prrx1b as negative regulators of adipogenesis. We show that Prrx1a and Prrx1b are down-regulated during adipogenesis in vitro and in vivo. Stable knockdown of Prrx1a/b enhances adipogenesis, with increased expression of peroxisome proliferator-activated receptor-γ, CCAAT/enhancer-binding protein-α and FABP4 and increased secretion of the adipokines adiponectin and chemerin. Although stable low-level expression of Prrx1a, Prrx1b, or Prrx2 does not affect 3T3-L1 adipogenesis, transient overexpression of Prrx1a or Prrx1b inhibits peroxisome proliferator-activated receptor-γ activity. Prrx1 knockdown decreases expression of Tgfb2 and Tgfb3, and inhibition of TGFβ signaling during adipogenesis mimics the effects of Prrx1 knockdown. These data support the hypothesis that endogenous Prrx1 restrains adipogenesis by regulating expression of TGFβ ligands and thereby activating TGFβ signaling. Finally, we find that expression of Prrx1a or Prrx1b in adipose tissue increases during obesity and strongly correlates with Tgfb3 expression in BL6 mice. These observations suggest that increased Prrx1 expression may promote TGFβ activity in adipose tissue and thereby contribute to aberrant adipocyte function during obesity.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Adipose Tissue; Animals; Down-Regulation; Gene Knockdown Techniques; Homeodomain Proteins; Humans; Ligands; Male; Mice; Mice, Inbred C57BL; Obesity; PPAR gamma; RNA, Messenger; Signal Transduction; Species Specificity; Transcription Factors; Transforming Growth Factor beta; Transforming Growth Factor beta3; Tumor Necrosis Factor-alpha; Wnt3A Protein

Accumulating evidence suggests that both an adverse prenatal and early postnatal environment increase susceptibility to renal and metabolic dysfunction later in life; however, whether exposure to adverse conditions during both prenatal and postnatal development act synergistically to potentiate the severity of renal and metabolic injury remains unknown. Sprague-Dawley rats were fed either a standard diet or a diet high in fat/fructose throughout pregnancy and lactation. After being weaned, female offspring were randomized to either standard diet or the high-fat/high-fructose diet, resulting in the following treatment groups: NF-NF, offspring of mothers fed a standard diet and fed a standard diet postnatally; NF-HF, offspring of mothers fed a standard diet and fed a high-fat/fructose diet postnatally; HF-NF, offspring of mothers fed a high-fat/fructose diet and fed a standard diet postnatally; HF-HF, offspring of mothers fed a high-fat/fructose diet and fed a high-fat/fructose diet postnatally. At the time of euthanasia (17 wk of age), HF-HF offspring weighed 30% more and had 110% more visceral fat than NF-NF offspring. The HF-HF offspring also had elevated blood glucose levels, glucose intolerance, 286% increase in urine albumin excretion, and 60% increase in glomerulosclerosis compared with NF-NF. In addition, HF-HF offspring exhibited a 100% increase in transforming growth factor-β protein expression and 116% increase in the abundance of infiltrated macrophages compared with the NF-NF offspring. These observations suggest that high-fat/fructose feeding during prenatal and throughout postnatal life increases the susceptibility to renal and metabolic injury later in life.

Topics: Albuminuria; Animals; Blood Glucose; Body Weight; Diet, High-Fat; Disease Susceptibility; Female; Fructose; Glomerulonephritis; Glucose Intolerance; Intra-Abdominal Fat; Macrophages; Metabolic Diseases; Obesity; Organ Size; Pregnancy; Prenatal Exposure Delayed Effects; Prenatal Nutritional Physiological Phenomena; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

In obesity, rapidly expanding adipose tissue becomes hypoxic, precipitating inflammation, fibrosis, and insulin resistance. Compensatory angiogenesis may prevent these events. Mice lacking the intracellular glucocorticoid-amplifying enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1(-/-)) have "healthier" adipose tissue distribution and resist metabolic disease with diet-induced obesity. Here we show that adipose tissues of 11βHSD1(-/-) mice exhibit attenuated hypoxia, induction of hypoxia-inducible factor (HIF-1α) activation of the TGF-β/Smad3/α-smooth muscle actin (α-SMA) signaling pathway, and fibrogenesis despite similar fat accretion with diet-induced obesity. Moreover, augmented 11βHSD1(-/-) adipose tissue angiogenesis is associated with enhanced peroxisome proliferator-activated receptor γ (PPARγ)-inducible expression of the potent angiogenic factors VEGF-A, apelin, and angiopoietin-like protein 4. Improved adipose angiogenesis and reduced fibrosis provide a novel mechanism whereby suppression of intracellular glucocorticoid regeneration promotes safer fat expansion with weight gain.

Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Actins; Adipokines; Adipose Tissue; Angiopoietin-Like Protein 4; Angiopoietins; Animals; Apelin; Fibrosis; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Insulin Resistance; Intercellular Signaling Peptides and Proteins; Male; Mice; Mice, Knockout; Neovascularization, Physiologic; Obesity; PPAR gamma; Signal Transduction; Smad3 Protein; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Weight Gain

This study evaluated early renal functional, structural, and biochemical changes in high-calorie/high-fat diet fed mice, a model of prediabetes and alimentary obesity. Male C57BL6/J mice were fed normal (11 kcal% fat) or high-fat (58 kcal% fat) diets for 16 wk. Renal changes were evaluated by histochemistry and immunohistochemistry, Western blot analysis, ELISA, enzymatic assays, and chemiluminometry. High-fat diet consumption led to increased body and kidney weights, impaired glucose tolerance, hyperinsulinemia, polyuria, a 2.7-fold increase in 24-h urinary albumin excretion, 20% increase in renal glomerular volume, 18% increase in renal collagen deposition, and 8% drop of glomerular podocytes. It also resulted in a 5.3-fold increase in urinary 8-isoprostane excretion and a 38% increase in renal cortex 4-hydroxynonenal adduct accumulation. 4-hydroxynonenal adduct level and immunoreactivity or Sirtuin 1 expression in renal medulla were not affected. Studies of potential mechanisms of the high-fat diet induced renal cortex oxidative injury revealed that whereas nicotinamide adenine dinucleotide phosphate reduced form oxidase activity only tended to increase, 12/15-lipoxygenase was significantly up-regulated, with approximately 12% increase in the enzyme protein expression and approximately 2-fold accumulation of 12(S)-hydroxyeicosatetraenoic acid, a marker of 12/15-lipoxygenase activity. Accumulation of periodic acid-Schiff -positive material, concentrations of TGF-β, sorbitol pathway intermediates, and expression of nephrin, CAAT/enhancer-binding protein homologous protein, phosphoeukaryotic initiation factor-α, and total eukaryotic initiation factor-α in the renal cortex were indistinguishable between experimental groups. Vascular endothelial growth factor concentrations were reduced in high-fat diet fed mice. In conclusion, systemic and renal cortex oxidative stress associated with 12/15-lipoxygenase overexpression and activation is an early phenomenon caused by high-calorie/high-fat diet consumption and a likely contributor to kidney disease associated with prediabetes and alimentary obesity.

Topics: Animal Feed; Animals; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Diabetic Nephropathies; Diet; Diet, High-Fat; Kidney Cortex; Male; Mice; Mice, Inbred C57BL; Models, Biological; Obesity; Oxidative Stress; Podocytes; Prediabetic State; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vascular Endothelial Growth Factor A

The present study was undertaken to characterize the remodeling phenotype of human adipose tissue (AT) macrophages (ATM) and to analyze their paracrine effects on AT progenitor cells.. The phenotype of ATM, immunoselected from subcutaneous (Sc) AT originating from subjects with wide range of body mass index and from paired biopsies of Sc and omental (Om) AT from obese subjects, was studied by gene expression analysis in the native and activated states. The paracrine effects of ScATM on the phenotype of human ScAT progenitor cells (CD34(+)CD31(-)) were investigated.. Two main ATM phenotypes were distinguished based on gene expression profiles. For ScAT-derived ATM, obesity and adipocyte-derived factors favored a pro-fibrotic/remodeling phenotype whereas the OmAT location and hypoxic culture conditions favored a pro-angiogenic phenotype. Treatment of native human ScAT progenitor cells with ScATM-conditioned media induced the appearance of myofibroblast-like cells as shown by expression of both α-SMA and the transcription factor SNAIL, an effect mimicked by TGFβ1 and activinA. Immunohistochemical analyses showed the presence of double positive α-SMA and CD34 cells in the stroma of human ScAT. Moreover, the mRNA levels of SNAIL and SLUG in ScAT progenitor cells were higher in obese compared with lean subjects.. Human ATM exhibit distinct pro-angiogenic and matrix remodeling/fibrotic phenotypes according to the adiposity and the location of AT, that may be related to AT microenvironment including hypoxia and adipokines. Moreover, human ScAT progenitor cells have been identified as target cells for ScATM-derived TGFβ and as a potential source of fibrosis through their induction of myofibroblast-like cells.

Topics: Adipose Tissue; Biomarkers; Blotting, Western; Body Composition; Body Mass Index; Cells, Cultured; Gene Expression Profiling; Humans; Immunoenzyme Techniques; Macrophages; Myofibroblasts; Obesity; Oligonucleotide Array Sequence Analysis; Omentum; Phenotype; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stem Cells; Subcutaneous Fat; Transforming Growth Factor beta

Obesity results from disproportionately high energy intake relative to energy expenditure. Many therapeutic strategies have focused on the intake side of the equation, including pharmaceutical targeting of appetite and digestion. An alternative approach is to increase energy expenditure through physical activity or adaptive thermogenesis. A pharmacological way to increase muscle mass and hence exercise capacity is through inhibition of the activin receptor type IIB (ActRIIB). Muscle mass and strength is regulated, at least in part, by growth factors that signal via ActRIIB. Administration of a soluble ActRIIB protein comprised of a form of the extracellular domain of ActRIIB fused to a human Fc (ActRIIB-Fc) results in a substantial muscle mass increase in normal mice. However, ActRIIB is also present on and mediates the action of growth factors in adipose tissue, although the function of this system is poorly understood. In the current study, we report the effect of ActRIIB-Fc to suppress diet-induced obesity and linked metabolic dysfunctions in mice fed a high-fat diet. ActRIIB-Fc induced a brown fat-like thermogenic gene program in epididymal white fat, as shown by robustly increased expression of the thermogenic genes uncoupling protein 1 and peroxisomal proliferator-activated receptor-γ coactivator 1α. Finally, we identified multiple ligands capable of reducing thermogenesis that represent likely target ligands for the ActRIIB-Fc effects on the white fat depots. These data demonstrate that novel therapeutic ActRIIB-Fc improves obesity and obesity-linked metabolic disease by both increasing skeletal muscle mass and by inducing a gene program of thermogenesis in the white adipose tissues.

Topics: Activin Receptors, Type II; Animals; Enzyme-Linked Immunosorbent Assay; Gene Expression Profiling; Humans; Immunohistochemistry; Ligands; Male; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Obesity; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Peroxisome Proliferator-Activated Receptors; Surface Plasmon Resonance; Thermogenesis; Tomography, X-Ray Computed; Trans-Activators; Transcription Factors; Transforming Growth Factor beta

Topics: Activin Receptors, Type II; Animals; Humans; Male; Obesity; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Trans-Activators; Transcription Factors; Transforming Growth Factor beta

Recent research implies a role of decreased number and/or function of T-regulatory cells (Tregs) in low-grade inflammation associated with obesity and atherosclerosis. The enhancement of atheroprotective immunity by the expansion of Tregs could serve as a therapeutic strategy in obesity-related immunological disturbances. The aim of our study was an attempt to generate Treg cells in children with risk factors for the development of cardiovascular disease and to compare the results to those obtained in healthy subjects. The study group consisted of 30 children with metabolic syndrome (MS) and 30 controls. Conventional CD4(+)CD25(-) cells separated from the peripheral blood were converted into Treg cells with the use of CD3/CD28 antibodies and interleukin (IL)-2/transforming growth factor (TGF)-β stimulation. The expression of critical Treg molecules and cytokines was assessed at mRNA and protein levels. The percentages of Treg cells in the peripheral blood were significantly lower in the children with MS compared to the healthy subjects. After the culture with CD3/CD28 and IL-2/TGF-β we detected a significant increase in the expression of Tregs marker transcription factor FoxP3. The Tregs induced from the children with MS varied from the ones obtained in the controls in the expression of some molecules at mRNA level (e.g. IL-27, LGAL, KLF10 and NRP1) yet not in proliferation studies. For the first time, we have demonstrated the possibility of generating functional Treg cells in children with MS. The results of our study could be used in the design of therapeutic interventions in obesity associated immunologic disturbances.

Topics: Adolescent; Age Factors; Antibodies; Case-Control Studies; CD28 Antigens; CD3 Complex; Cell Proliferation; Cells, Cultured; Female; Forkhead Transcription Factors; Gene Expression Regulation; Humans; Interleukin-2; Lymphocyte Activation; Male; Metabolic Syndrome; Obesity; RNA, Messenger; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

Obesity is a risk factor for the development of chronic kidney disease (CKD) and end-stage renal disease. It is not clear whether the adoption of a high-protein diet in obese patients affects renal lipid metabolism or kidney function. Thus the aims of this study were to assess in obese Zuckerfa/fa rats the effects of different types and amounts of dietary protein on the expression of lipogenic and inflammatory genes, as well as renal lipid concentration and biochemical parameters of kidney function. Rats were fed different concentrations of soy protein or casein (20, 30, 45%) for 2 mo. Independent of the type of protein ingested, higher dietary protein intake led to higher serum triglycerides (TG) than rats fed adequate concentrations of protein. Additionally, the soy protein diet significantly increased serum TG compared with the casein diet. However, rats fed soy protein had significantly decreased serum cholesterol concentrations compared with those fed a casein diet. No significant differences in renal TG and cholesterol concentrations were observed between rats fed with either protein diets. Renal expression of sterol-regulatory element binding protein 2 (SREBP-2) and its target gene HMG-CoA reductase was significantly increased as the concentration of dietary protein increased. The highest protein diets were associated with greater expression of proinflammatory cytokines in the kidney, independent of the type of dietary protein. These results indicate that high soy or casein protein diets upregulate the expression of lipogenic and proinflammatory genes in the kidney.

Topics: Animals; Blood Glucose; Caseins; Cholesterol; Collagen Type IV; Dietary Proteins; Hydrogen Peroxide; Hydroxymethylglutaryl CoA Reductases; Insulin; Interleukin-6; Kidney; Lipogenesis; Obesity; Organ Size; Oxidative Stress; Rats; Rats, Zucker; Soybean Proteins; Sterol Regulatory Element Binding Protein 1; Sterol Regulatory Element Binding Protein 2; Transforming Growth Factor beta; Triglycerides; Tumor Necrosis Factor-alpha

We aimed at elucidating the roles of transforming growth factor (TGF)-β and Smad3 signaling in adipocyte differentiation (adipogenesis) and in the pathogenesis of obesity. TGF-β/Smad3 signaling in white adipose tissue (WAT) was determined in genetically obese (ob/ob) mice. The effect of TGF-β on adipogenesis was evaluated in mouse embryonic fibroblasts (MEF) isolated both from WT controls and Smad3 KO mice by Oil red-O staining and gene expression analysis. Phenotypic analyses of high-fat diet (HFD)-induced obesity in Smad3 KO mice compared to WT controls were performed. TGF-β/Smad3 signaling was elevated in WAT from ob/ob mice compared to the controls. TGF-β significantly inhibited adipogenesis in MEF, but the inhibitory effects of TGF-β on adipogenesis were partially abolished in MEF from Smad3 KO mice. TGF-β inhibited adipogenesis independent from the Wnt and β-catenin pathway. Smad3 KO mice were protected against HFD-induced insulin resistance. The size of adipocytes from Smad3 KO mice on the HFD was significantly smaller compared to the controls. In conclusion, the TGF-β/Smad3 signaling pathway plays key roles not only in adipogenesis but also in development of insulin resistance.

Topics: Adipocytes, White; Adipogenesis; Adipose Tissue, White; Animals; Insulin; Insulin Resistance; Male; Mice; Mice, Knockout; Obesity; Smad3 Protein; Transforming Growth Factor beta

The proportions of body fat and fat-free mass are determining factors of adiposity-associated diseases. Work in Caenorhabditis elegans has revealed evolutionarily conserved pathways of fat metabolism. Nevertheless, analysis of body composition and fat distribution in the nematodes has only been partially unraveled because of methodological difficulties. We characterized metabolic C. elegans mutants by using novel and feasible BODIPY 493/503-based fat staining and flow cytometry approaches. Fixative as well as vital BODIPY staining procedures visualize major fat stores, preserve native lipid droplet morphology, and allow quantification of fat content per body volume of individual worms. Colocalization studies using coherent anti-Stokes Raman scattering microscopy, Raman microspectroscopy, and imaging of lysosome-related organelles as well as biochemical measurement confirm our approaches. We found that the fat-to-volume ratio of dietary restriction, TGF-β, and germline mutants are specific for each strain. In contrast, the proportion of fat-free mass is constant between the mutants, although their volumes differ by a factor of 3. Our approaches enable sensitive, accurate, and high-throughput assessment of adiposity in large C. elegans populations at a single-worm level.

Topics: Adipose Tissue; Adiposity; Animals; Azo Compounds; Boron Compounds; Caenorhabditis elegans; Disease Models, Animal; Fixatives; Flow Cytometry; Fluorescence; Germ-Line Mutation; High-Throughput Screening Assays; Lipid Metabolism; Microscopy; Obesity; Species Specificity; Spectrum Analysis, Raman; Staining and Labeling; Transforming Growth Factor beta

Both maternal obesity and inflammatory bowel diseases (IBDs) are increasing. It was hypothesized that maternal obesity induces an inflammatory response in the fetal large intestine, predisposing offspring to IBDs.. Nonpregnant ewes were assigned to a control (Con, 100% of National Research Council [NRC] recommendations) or obesogenic (OB, 150% of NRC) diet from 60 days before conception. The large intestine was sampled from fetuses at 135 days (term 150 days) after conception and from offspring lambs at 22.5 ± 0.5 months of age.. Maternal obesity enhanced mRNA expression tumor necrosis factor (TNF)α, interleukin (IL)1α, IL1β, IL6, IL8, and monocyte/macrophage chemotactic protein-1 (MCP1), as well as macrophage markers, CD11b, CD14, and CD68 in fetal gut. mRNA expression of Toll-like receptor (TLR) 2 and TLR4 was increased in OB versus Con fetuses; correspondingly, inflammatory NF-κB and JNK signaling pathways were also upregulated. Both mRNA expression and protein content of transforming growth factor (TGF) β was increased. The IL-17A mRNA expression and protein content was higher in OB compared to Con samples, which was associated with fibrosis in the large intestine of OB fetuses. Similar inflammatory responses and enhanced fibrosis were detected in OB compared to Con offspring.. Maternal obesity induced inflammation and enhanced expression of proinflammatory cytokines in fetal and offspring large intestine, which correlated with increased TGFβ and IL17 expression. These data show that maternal obesity may predispose offspring gut to IBDs.

Topics: Animals; Animals, Newborn; Blotting, Western; Cytokines; Female; Fetus; Fibrosis; Inflammation; Interleukin-17; Intestine, Large; Maternal Nutritional Physiological Phenomena; NF-kappa B; Obesity; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sheep; Transforming Growth Factor beta

Imbalances in glucose and energy homeostasis are at the core of the worldwide epidemic of obesity and diabetes. Here, we illustrate an important role of the TGF-β/Smad3 signaling pathway in regulating glucose and energy homeostasis. Smad3-deficient mice are protected from diet-induced obesity and diabetes. Interestingly, the metabolic protection is accompanied by Smad3(-)(/-) white adipose tissue acquiring the bioenergetic and gene expression profile of brown fat/skeletal muscle. Smad3(-/-) adipocytes demonstrate a marked increase in mitochondrial biogenesis, with a corresponding increase in basal respiration, and Smad3 acts as a repressor of PGC-1α expression. We observe significant correlation between TGF-β1 levels and adiposity in rodents and humans. Further, systemic blockade of TGF-β signaling protects mice from obesity, diabetes, and hepatic steatosis. Together, these results demonstrate that TGF-β signaling regulates glucose tolerance and energy homeostasis and suggest that modulation of TGF-β activity might be an effective treatment strategy for obesity and diabetes.

Topics: Adipose Tissue, Brown; Adipose Tissue, White; Animals; Antibodies; Diabetes Mellitus; DNA-Binding Proteins; Energy Metabolism; Glucose Tolerance Test; Mice; Mice, Knockout; Mice, Obese; Mitochondria; Obesity; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Signal Transduction; Smad3 Protein; Trans-Activators; Transcription Factors; Transforming Growth Factor beta

The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion. Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell.. Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.

Topics: Animals; Cell Proliferation; Cell Survival; Cholesterol; Down-Regulation; Female; Gene Expression Regulation; Gene Knockout Techniques; Insulin Resistance; Insulin-Secreting Cells; Mice; Obesity; Oxidation-Reduction; Phosphorylation; PPAR gamma; Signal Transduction; Transcription, Genetic; Transforming Growth Factor beta

The prevalence of pancreatic adenocarcinoma (PAC) parallels rising rates of obesity and dysmetabolism, a possible link being non-alcoholic fatty pancreas disease (NAFPD). We have recently shown that maternal obesity programmes the development of a dysmetabolic and fatty liver (non-alcoholic fatty liver disease, NAFLD) phenotype in adult offspring. Since the pancreas and liver originate from the same embryonic bud, it is plausible that maternal obesity may similarly programme the development of NAFPD. Our objective was to determine the effect of maternal obesity on development of NAFPD in offspring and ascertain contributions of the intra/extra-uterine periods.. Female C57BL/6J mice were fed either a standard chow (3% fat, 7% sugar) or a hypercalorific diet (16% fat, 33% sugar) for six weeks prior to mating and throughout pregnancy and lactation. Female offspring were cross-fostered for suckling to dams on the same or opposite diet to yield four groups: offspring of lean suckled by lean dams (n=6), offspring of obese suckled by obese dams (n=6), offspring of lean suckled by obese dams (n=5) and offspring of obese suckled by lean dams (n=6). All offspring were weaned onto a standard chow diet at 21 days and sacrificed at 3 months post-partum for tissue collection.. Offspring subjected to an adverse suckling environment showed significant increases in body weight, pancreatic triglyceride content, TGF-beta, collagen gene expression and SBP at rest along with an enhanced restraint stress response, indicating a dysmetabolic and NAFPD phenotype.. Developmental programming is involved in the pathogenesis of NAFPD and appears to be largely dependent on an adverse extra-uterine environment.

Topics: Animals; Animals, Suckling; Blood Pressure; Body Weight; Collagen Type I; Fatty Acids; Female; Mice; Mice, Inbred C57BL; Obesity; Pancreatic Diseases; Pregnancy; Pregnancy Complications; Prenatal Exposure Delayed Effects; Sympathetic Nervous System; Transforming Growth Factor beta

Maternal obesity (MO) is increasing at an alarming rate. The objective of this study was to evaluate the effect of MO on fibrogenesis in fetal skeletal muscle during maturation in late gestation. Nonpregnant ewes were assigned to a control diet (Con; fed 100% of NRC nutrient recommendations, n = 6) or obesogenic diet (OB; fed 150% of NRC recommendations, n = 6) from 60 days before conception, and fetal semitendenosus (St) muscle was sampled at 135 days of gestation (term 148 days). Total concentration and area of collagen in cross-sections of muscle increased by 27.0 +/- 6.0 (P < 0.05) and 105.1 +/- 5.9% (P = 0.05) in OB compared with Con fetuses. The expression of precursor TGF-beta was 177.3 +/- 47.6% higher, and concentration of phospho-p38 74.7 +/- 23.6% was higher (P < 0.05) in OB than in CON fetal muscle. Increases of 327.9 +/- 168.0 (P < 0.05) and 188.9 +/- 82.1% (P < 0.05), respectively, were observed for mRNA expression of Smad7 and fibronectin in OB compared with Con muscles. In addition, enzymes involved in collagen synthesis, including lysyl oxidase, lysyl hydroxylase 2b, and prolyl 4-hydroxylase-alpha1, were increased by 350.2 +/- 90.0 (P < 0.05), 236.5 +/- 25.2 (P < 0.05), and 82.0 +/- 36.2% (P = 0.05), respectively, in OB muscle. In conclusion, MO-enhanced fibrogenesis in fetal muscle in late gestation was associated with upregulation of the TGF-beta/p38 signaling pathway. Enhanced fibrogenesis at such an early stage of development is expected to negatively affect the properties of offspring muscle because muscle fibrosis is a hallmark of aging.

Topics: Animals; Blotting, Western; Collagen Type I; Electrophoretic Mobility Shift Assay; Female; Fetus; Fibronectins; Linear Models; Male; Muscle Fibers, Skeletal; Obesity; Pregnancy; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; Procollagen-Proline Dioxygenase; Protein-Lysine 6-Oxidase; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sheep; Signal Transduction; Smad7 Protein; Transforming Growth Factor beta; Tubulin

Adiposity contributes to the insulin resistance and endothelial dysfunction of the hypertensive state; the inflammatory network and the metalloprotease (MMP)/ tissue inhibitor of metalloprotease (TIMP) system modulate vascular structure and function.. We measured interleukin-6 (IL-6); plasminogen activator inhibitor-1 (PAI-1); tumor necrosis factor-alpha; transforming growth factor-beta; MMP-2, MMP-9, TIMP-1, and TIMP-2 expression; MMP-2 and MMP-9 activity; and TIMP-1 and TIMP-2 protein in adipocytes isolated from paired samples of visceral and subcutaneous adipose tissue of 30 nonobese, untreated hypertensive patients and 20 normotensive controls.. Although expression of IL-6, PAI-1, tumor necrosis factor-alpha, and transforming growth factor-beta were generally higher in visceral adipocytes, IL-6, PAI-1, and tumor necrosis factor-alpha were overexpressed, and transforming growth factor-beta was underexpressed in hypertensive vs. controls (all P<0.0001). These changes were paralleled by higher circulating IL-6 and PAI-1 levels in hypertensive patients. MMP-2 and TIMP-2 expression - which were higher in subcutaneous than visceral cells - were reduced in hypertensive patients (all P<0.0001), whereas MMP-9 and TIMP-1 did not differ between the two groups. Both MMP-2 and MMP-9 activity were reduced in hypertensive patients (all P<0.0001). In the whole dataset, SBP and DBP were directly related to IL-6 and PAI-1 expression and inversely to MMP-2 and MMP-9 activity.. Adipocytes from both visceral and subcutaneous depots of untreated hypertensive patients show a pattern of expression of inflammatory and MMP/TIMP molecules that is compatible with the raised circulating levels of inflammatory markers, is quantitatively related to the height of blood pressure, and provides the cellular basis for the proinflammatory and prothrombotic predisposition of these patients.

Topics: Adipose Tissue; Aged; Biomarkers; Case-Control Studies; Female; Humans; Hypertension; Inflammation; Inflammation Mediators; Interleukin-6; Male; Matrix Metalloproteinase 9; Matrix Metalloproteinases; Middle Aged; Obesity; Plasminogen Activator Inhibitor 1; Subcutaneous Tissue; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Diets high in saturated fat and fructose have been implicated in the development of obesity and nonalcoholic steatohepatitis (NASH) in humans. We hypothesized that mice exposed to a similar diet would develop NASH with fibrosis associated with increased hepatic oxidative stress that would be further reflected by increased plasma levels of the respiratory chain component, oxidized coenzyme Q9 ((ox)CoQ9). Adult male C57Bl/6 mice were randomly assigned to chow, high-fat (HF), or high-fat high-carbohydrate (HFHC) diets for 16 weeks. The chow and HF mice had free access to pure water, whereas the HFHC group received water with 55% fructose and 45% sucrose (wt/vol). The HFHC and HF groups had increased body weight, body fat mass, fasting glucose, and were insulin-resistant compared with chow mice. HF and HFHC consumed similar calories. Hepatic triglyceride content, plasma alanine aminotransferase, and liver weight were significantly increased in HF and HFHC mice compared with chow mice. Plasma cholesterol (P < 0.001), histological hepatic fibrosis, liver hydroxyproline content (P = 0.006), collagen 1 messenger RNA (P = 0.003), CD11b-F4/80+Gr1+ monocytes (P < 0.0001), transforming growth factor beta1 mRNA (P = 0.04), and alpha-smooth muscle actin messenger RNA (P = 0.001) levels were significantly increased in HFHC mice. Hepatic oxidative stress, as indicated by liver superoxide expression (P = 0.002), 4-hydroxynonenal, and plasma (ox)CoQ9 (P < 0.001) levels, was highest in HFHC mice.. These findings demonstrate that nongenetically modified mice maintained on an HFHC diet in addition to developing obesity have increased hepatic ROS and a NASH-like phenotype with significant fibrosis. Plasma (ox)CoQ9 correlated with fibrosis progression. The mechanism of fibrosis may involve fructose inducing increased ROS associated with CD11b+F4/80+Gr1+ hepatic macrophage aggregation, resulting in transforming growth factor beta1-signaled collagen deposition and histologically visible hepatic fibrosis.

Topics: Animals; Body Composition; Collagen; Dietary Carbohydrates; Dietary Fats; Disease Models, Animal; Fatty Liver; Fructose; Insulin Resistance; Liver; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Obesity; Reactive Oxygen Species; Trans Fatty Acids; Transforming Growth Factor beta; Ubiquinone

Recent genome-wide association (GWA) studies have identified several novel genetic loci associated with age at menarche and age at natural menopause. However, the stringent significance threshold used in GWA studies potentially led to false negatives and true associations may have been overlooked. Incorporating biologically relevant information, we examined whether common genetic polymorphisms in candidate genes of nine groups of biologically plausible pathways and related phenotypes are associated with age at menarche and age at natural menopause. A total of 18,862 genotyped and imputed single nucleotide polymorphisms (SNPs) in 278 genes were assessed for their associations with these two traits among a total of 24,341 women from the Nurses' Health Study (NHS, N = 2,287) and the Women's Genome Health Study (WGHS, N = 22,054). Linear regression was used to assess the marginal association of each SNP with each phenotype. We adjusted for multiple testing within each gene to identify statistically significant SNP associations at the gene level. To evaluate the overall evidence for an excess of statistically significant gene associations over the proportion expected by chance, we applied a one-sample test of proportion to each group of candidate genes. The steroid-hormone metabolism and biosynthesis pathway was found significantly associated with both age at menarche and age at natural menopause (P = 0.040 and 0.011, respectively). In addition, the group of genes associated with precocious or delayed puberty was found significantly associated with age at menarche (P = 0.013), and the group of genes involved in premature ovarian failure with age at menopause (P = 0.025).

Topics: Adolescent; Age Factors; Age of Onset; Child; Female; Genetic Association Studies; Genetic Predisposition to Disease; Genotype; Gonadal Steroid Hormones; Humans; Linear Models; Menarche; Menopause; Middle Aged; Nurses; Obesity; Phenotype; Polycystic Ovary Syndrome; Polymorphism, Single Nucleotide; Primary Ovarian Insufficiency; Puberty, Delayed; Puberty, Precocious; Signal Transduction; Smoking; Somatomedins; Thrombophilia; Tobacco Use Disorder; Transforming Growth Factor beta; Women's Health

Maternal obesity (MO) has harmful effects on both fetal development and subsequent offspring health. The impact of MO on fetal myocardium development has received little attention. Fibrogenesis is regulated by the transforming growth factor-β (TGF-β)/p38 signaling pathway. Using the well-established model of MO in pregnant sheep, we evaluated the effect of MO on TGF-β/p38 and collagen accumulation in fetal myocardium. Nonpregnant ewes were assigned to a control diet [Con, fed 100% of National Research Council (NRC) nutrient recommendations] or obesogenic diet (OB, fed 150% of NRC recommendations) from 60 days before conception. Fetal ventricular muscle was sampled at 75 and 135 days of gestation (dG). At 75 dG, the expression of precursor TGF-β was 39.9 ± 9.9% higher (P < 0.05) in OB than Con fetal myocardium, consistent with the higher content of phosphorylated Smad3 in OB myocardium. The phosphorylation of p38 tended to be higher in OB myocardium (P = 0.08). In addition, enhanced Smad complexes were bound to Smad-binding elements in 75 dG OB fetal myocardium measured by DNA mobility shift assay (130.2 ± 26.0% higher, P < 0.05). Similar elevation of TGF-β signaling was observed in OB fetal myocardium at 135 dG. Total collagen concentration in OB was greater than Con fetal myocardium (2.42 ± 0.16 vs. 1.87 ± 0.04%, P < 0.05). Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-3 were higher in the Con group compared with OB sheep (43.86 ± 16.01 and 37.23 ± 7.97% respectively, P < 0.05). In summary, MO results in greater fetal heart connective tissue accumulation associated with an upregulated TGF-β/p38 signaling pathway at late gestation; such changes would be expected to negatively impact offspring heart function.

Topics: Animals; Blotting, Western; Female; Fibrosis; Heart; Maternal Nutritional Physiological Phenomena; Matrix Metalloproteinase 9; Myocardium; Obesity; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Pregnancy; Reverse Transcriptase Polymerase Chain Reaction; Sheep; Signal Transduction; Tissue Inhibitor of Metalloproteinase-3; Transforming Growth Factor beta

Topics: Bariatric Surgery; Biomarkers; Burns; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Neoplasms; Obesity; Organ Transplantation; Plastic Surgery Procedures; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Weight Loss; Wound Healing

We previously showed that long-term consumption of a soy protein diet (SoyP) reduces renal damage in obese Zucker (ObeseZ) rats by restoring urinary NO2 and NO3 excretion (UNO2/NO3V), suggesting that nitric oxide (NO) deficiency may contribute to the renal progression observed in this model. In addition, there is compelling evidence that hyperleptinemia produced deleterious effects on the kidney through its interaction with the short leptin receptor (ObRa). This study was designed to evaluate the contribution of the NO/endothelial NO synthase (eNOS) system, renal oxidative stress, and ObRa expression to the renoprotection conferred by the consumption of a SoyP in ObeseZ rats. Ten lean and ten male ObeseZ rats were included. One-half of each group was fed with a 20% SoyP and the other half with a 20% casein protein diet (CasP) over the course of 160 days. eNOS protein levels and phosphorylation, renal lipoperoxidation (rLPO), and antioxidant enzyme activity were assessed. In addition, renal ObRa, TGF-beta, and kidney injury molecule (Kim-1) mRNA levels, as well as urinary Kim-1 levels, were measured. Renal injury observed in ObeseZ rats fed with CasP was not associated with changes in eNOS expression or phosphorylation. However, this group did present with increased rLPO, reduced catalase activity, and upregulation of ObRa, TGF-beta1, and Kim-1. In contrast, ObeseZ rats fed with a SoyP exhibited a reduction in NOS-Thr495 phosphorylation and rLPO, as well as an enhanced catalase activity. These findings were associated with a significant reduction of ObRa, TGF-beta1, and Kim-1 mRNA levels and urinary Kim-1 protein. Our results show that renoprotection by SoyP in ObeseZ rats is in part mediated by increased NO availability secondary to a reduction in eNOS-T495 phosphorylation and oxidative stress, together with a significant reduction in ObRa and TGF-beta expression.

Topics: Administration, Oral; Animals; Antioxidants; Blotting, Western; Caseins; Cell Adhesion Molecules; Dietary Proteins; Enzyme-Linked Immunosorbent Assay; Gene Expression; Kidney; Kidney Diseases; Kidney Glomerulus; Leptin; Lipid Peroxidation; Male; Nitric Oxide Synthase Type III; Obesity; Oxidative Stress; Phosphorylation; Rats; Rats, Zucker; Receptors, Leptin; Reverse Transcriptase Polymerase Chain Reaction; Soybean Proteins; Transforming Growth Factor beta

Medications to treat hyperglycemia and hyperinsulinemia are expected to inhibit the accumulation of advanced glycation end-products in the diabetic kidney and improve renal function by inhibiting oxidative reactions. In this study, we examined the effect of pioglitazone, an insulin sensitizer, on diabetic nephropathy. Feed containing pioglitazone at 0.01 or 0.02% was given to Zucker-fatty rats for 27 weeks. Pioglitazone reduced plasma glucose, plasma insulin, and blood HbAlc levels. It also decreased plasma total cholesterol, triglyceride, phospholipid and cystatin C levels and inhibited the increase in urine of 8-hydroxydeoxyguanosine and in plasma of malondialdehyde. In the histopathological examinations, pioglitazone inhibited diffusive or nodular thickening of the mesangial matrix, atrophy of the proximal convoluted tubule, thickening of the basement membrane of the tubule, and mild cellular infiltration (mostly small lymphocytes) in the stroma. Furthermore, pioglitazone inhibited the mRNA expression of the receptor for advanced glycation end-products (RAGE) and that of transforming growth factor-beta. Long-term administration of pioglitazone improved hyperglycemia lipid profiles, hypercholesterolemia, and hyperinsulinemia and had a protective effect on diabetic nephropathy in Zucker-fatty rats.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blood Glucose; Cholesterol; Cystatin C; Cystatins; Diabetic Nephropathies; Glycated Hemoglobin; Guanine; Hypoglycemic Agents; Insulin; Kidney; Malondialdehyde; Obesity; Oxidation-Reduction; Phospholipids; Pioglitazone; Rats; Rats, Zucker; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Thiazolidinediones; Transforming Growth Factor beta; Triglycerides

Chronic renal hypoxia is suspected to play a pathogenic role in the genesis of diabetic nephropathy (DN). Cobalt enhances the activity of the hypoxia-inducible factor (HIF), a key factor in the defence against hypoxia. Its long-term effect on DN is evaluated.. Cobalt chloride was given to hypertensive, type 2 diabetic rats with nephropathy (SHR/NDmcr-cp). Treatment was initiated at the age of 13 weeks and continued for 26 weeks.. Cobalt did not correct hypertension and metabolic abnormalities (obesity, hyperglycaemia and hyperlipidaemia) but reduced proteinuria as well as histological kidney injury. Cobalt upregulated renal HIF-1alpha and HIF-2alpha expression and increased the expression of HIF-regulated genes, including erythropoietin, vascular endothelial growth factor and heme oxygenase-1. The renal expression of transforming growth factor (TGF)-beta and connective tissue growth factor (CTGF) was significantly reduced by cobalt. The renal expression of NADPH oxidase, a marker of oxidative stress, and the renal content of pentosidine, a marker of advanced glycation, were also significantly reduced by cobalt.. Cobalt achieved renal protection independently of metabolic status and blood pressure. Its effect was attributed to the upregulation of HIF and HIF-regulated genes and to a mitigated advanced glycation and oxidative stress.

Topics: Animals; Antimutagenic Agents; Arginine; Basic Helix-Loop-Helix Transcription Factors; Blood Pressure; Blotting, Western; Chromatography, High Pressure Liquid; Cobalt; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Gene Expression; Glycation End Products, Advanced; Hypertension; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Immediate-Early Proteins; Insulin-Like Growth Factor Binding Proteins; Intercellular Signaling Peptides and Proteins; Kidney; Lysine; Male; NADPH Oxidases; Obesity; Oxidative Stress; Polymerase Chain Reaction; Rats; Rats, Inbred SHR; RNA, Messenger; Transforming Growth Factor beta

Myostatin, a member of the TGF-beta superfamily, is produced by skeletal muscle and acts as a negative regulator of muscle mass. It has also been suggested that low-dose administration of myostatin (2 mug/day) in rodents can reduce fat mass without altering muscle mass. In the current study, we attempted to further explore the effects of myostatin on adipocytes and its potential to reduce fat mass, since myostatin administration could potentially be a useful strategy to treat obesity and its complications in humans.. Purified myostatin protein was examined for its effects on adipogenesis and lipolysis in differentiated 3T3-L1 adipocytes as well as for effects on fat mass in wild-type, myostatin null and obese mice.. While myostatin was capable of inhibiting adipogenesis in 3T3-L1 cells, it did not alter lipolysis in fully differentiated adipocytes. Importantly, pharmacological administration of myostatin over a range of doses (2-120 mug/day) did not affect fat mass in wild-type or genetically obese (ob/ob, db/db) mice, although muscle mass was significantly reduced at the highest myostatin dose.. Our results suggest that myostatin does not reduce adipose stores in adult animals. Contrary to prior indications, pharmacological administration of myostatin does not appear to be an effective strategy to treat obesity in vivo.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Animals; Lipolysis; Mice; Myostatin; Obesity; Transforming Growth Factor beta; Treatment Outcome

Non-alcoholic steatohepatitis (NASH), which is a common liver disease in industrialized countries, is associated with obesity, hypertension, and type-2 diabetes (metabolic syndrome). Since angiotensin II (ANG II) has been suggested to play an important role in liver inflammation and fibrosis, the purpose of this study was to investigate whether therapy against renin-angiotensin system (RAS) may provide some beneficial effect in liver of an animal model of metabolic syndrome.. For 6 months, obese Zucker rats (OZRs) were treated as follows: OZR-group, OZR + Perindopril (P) group, OZR + Irbesartan (IRB) group, OZR + Amlodipine (AML) group, and lean Zucker rats (LZRs) group as a control. Livers were evaluated by immunohistochemistry techniques using corresponding antibodies.. All treated groups showed a similar reduction in blood pressure compared to untreated OZR. Therapy either with IRB or P improves insulin sensitivity and reduces hepatic enzyme level with respect to untreated OZR. Conversely, AML failed to modify both parameters. Untreated OZR displayed higher hepatic ANG II levels and steatosis together with a marked increase in tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and transforming growth factor-beta1 (TGF-beta1) level compared to LZR. Following RAS inhibition either by P or IRB, a significant reduction (P < 0.01) in the immunostaining of TNF-alpha, IL-6 and TGF-beta1 compared to untreated OZR was observed.. These results indicate that ANG II expression is increased in the liver of these animals with steatohepatitis. Furthermore, RAS control by either angiotensin-converting enzyme inhibition or AT1 receptor blockade seems to provide a beneficial modulation concerning the inflammatory response to liver injury in this model. Consequently, blockade of RAS could be a new approach to prevent or to treat patients with NASH.

Topics: Amlodipine; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Biphenyl Compounds; Disease Models, Animal; Fatty Liver; Interleukin-6; Irbesartan; Liver; Liver Cirrhosis; Male; Metabolic Syndrome; Obesity; Perindopril; Rats; Rats, Zucker; Renin-Angiotensin System; Tetrazoles; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Obesity is associated with the changes of plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-alpha (TNFalpha) and transforming growth factor beta (TGFbeta) levels. However, the precise effect of the 4G allele on obesity is still contradictory. Here, we aimed to elucidate the role of the 4G/5G polymorphism of the PAI-1 gene on the PAI-1 level and determine the associations between cytokines, glucose and lipid metabolism parameters in obese children. Thirty-nine obese children (mean age 11.4 +/- 3.3 years) and 38 age-matched healthy control group (mean age 10.3 +/- 3.5 years) were included in the study. In all cases, serum levels of glucose, lipid and insulin were measured, homeostasis model assessment of insulin resistance (HOMA-IR) was calculated, and 4G/5G polymorphism of PAI-1 gene, plasma PAI-1 level and serum TNFalpha and TGFbeta levels were studied. The mean relative body mass index (BMI) and HOMA-IR score, VLDL, TG, insulin, PAI-1, TNFalpha levels were higher, and HDL and TGFbeta levels were lower in the obese group. The frequency of the 4G/4G genotype was considerably higher in obese children than in controls. Also, a positive correlation was found between PAI-1 and TNFalpha levels, and relative BMI, HOMA-IR score, insulin, TG, HDL levels. TGFbeta was inversely correlated only with relative BMI. There was no correlation among three cytokines. In conclusion, childhood obesity contributes to higher PAI-1 and TNFalpha and lower TGFbeta levels. Especially PAI-1 and TNFalpha accompany insulin resistance and dyslipidemia.

Topics: Adipose Tissue; Adolescent; Blood Glucose; Body Mass Index; Case-Control Studies; Child; Cytokines; Female; Genetic Predisposition to Disease; Humans; Insulin; Insulin Resistance; Lipid Metabolism; Lipids; Male; Obesity; Phenotype; Plasminogen Activator Inhibitor 1; Polymorphism, Genetic; Promoter Regions, Genetic; Risk Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Myostatin (MSTN) is a secreted growth inhibitor expressed in muscle and adipose. We sought to determine whether expression of MSTN, its receptor activin RIIb (ActRIIb), or its binding protein follistatin-like-3 (FSTL3) are altered in subcutaneous or visceral adipose or in skeletal muscle in response to obesity. MSTN and ActRIIb mRNA levels were low in subcutaneous (SQF) and visceral fat (VF) from wild-type mice but were 50- to 100-fold higher in both SQF and VF from ob/ob compared with wild-type mice. FSTL3 mRNA levels were increased in SQF but decreased in VF in ob/ob compared with wild-type mice. Moreover, MSTN mRNA levels were twofold greater in tibialis anterior (TA) from ob/ob mice, whereas ActRIIb and FSTL3 mRNA levels were unchanged. MSTN mRNA levels were also increased in TA and SQF from mice on a high-fat diet. Injection of ob/ob mice with recombinant leptin caused FSTL3 mRNA levels to decrease in both VF and SQF in ob/ob mice; MSTN and ActRIIb mRNA levels tended to decrease only in VF. Finally, MSTN mRNA levels and promoter activity were low in adipogenic 3T3-L1 cells, but an MSTN promoter-reporter construct was activated in 3T3-L1 cells by cotransfection with the adipogenic transcription factors SREBP-1c, C/EBPalpha, and PPARgamma. These results demonstrate that expression of MSTN and its associated binding proteins can be modulated in adipose tissue and skeletal muscle by chronic obesity and suggest that alterations in their expression may contribute to the changes in growth and metabolism of lean and fat tissues occurring during obesity.

Topics: 3T3 Cells; Activin Receptors, Type II; Adipose Tissue; Animals; Cells, Cultured; Cloning, Molecular; Diet; Dietary Fats; DNA; Follistatin-Related Proteins; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Muscle, Skeletal; Myostatin; Obesity; Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Transfection; Transforming Growth Factor beta

Growth/differentiation factor 3 (GDF3) is highly expressed in adipose tissue, and previous overexpression experiments in mice have suggested that it may act as an adipogenic factor under conditions of high lipid load. GDF3 has been shown to signal via the activin receptor ALK4 during embryogenesis, but functional receptors in adipose tissue are unknown. In this study, we show that Gdf3(-/-) mutant mice accumulate less adipose tissue than WT animals and show partial resistance to high-fat diet-induced obesity despite similar food intake. We also demonstrate that GDF3 can signal via the ALK4-homolog ALK7 and the coreceptor Cripto, both of which are expressed in adipose tissue. In agreement with a role for ALK7 in GDF3 signaling in vivo, mutant mice lacking ALK7 also showed reduced fat accumulation and partial resistance to diet-induced obesity. We propose that GDF3 regulates adipose-tissue homeostasis and energy balance under nutrient overload in part by signaling through the ALK7 receptor.

Topics: Activin Receptors, Type I; Adipose Tissue; Animal Feed; Animals; Diet; Gene Expression Regulation; Growth Differentiation Factor 3; Humans; Insulin; Intercellular Signaling Peptides and Proteins; Mice; Mice, Transgenic; Obesity; Transforming Growth Factor beta

The increasing prevalence of nonalcoholic steatohepatitis (NASH) is due to the epidemic of obesity and type 2 diabetes, both of which are associated with insulin resistance.. To clarify the causal relationship between insulin resistance and the development of NASH, steatohepatitis was induced in obese diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) and nondiabetic control Long-Evans Tokushima Otsuka (LETO) rats by feeding them a methionine and choline-deficient (MCD) diet. Insulin sensitivity of the rats was altered by adding a high-fat (HF) diet or the peroxisomal-proliferator activated receptor-gamma agonist pioglitazone to the MCD diet.. The MCD diet-induced steatohepatitis was accelerated in OLETF rats after 8 weeks. Steatosis preceded inflammation, which led to fibrosis and the development of steatohepatitis. The hepatic gene expression for transforming growth factor-beta, alpha1 procollagen and plasminogen activator inhibitor-1 was up-regulated in OLETF rats compared with LETO rats. The MCD + HF diet further enhanced insulin resistance and led to rapid development of pre-cirrhosis in OLETF rats by increasing the triglyceride pool, activating stellate cells, and up-regulating gene expression for sterol regulatory element-binding protein-1c and fatty acid synthase in the liver. In contrast, pioglitazone attenuated the MCD diet-induced steatohepatitis in OLETF rats but not in LETO rats by reversing the underlying pathogenesis involved in this model through improvement of insulin resistance. These results confirm a link between insulin resistance and the development/progression of steatohepatitis, at least partly via up-regulation of genes for lipogenesis, inflammation, and fibrogenesis, in animal models.. Insulin resistance and/or diabetes may accelerate the entire pathologic spectrum of NASH.

Topics: Animal Feed; Animals; Choline; Collagen Type I; Collagen Type I, alpha 1 Chain; Diabetes Mellitus, Type 2; Dietary Fats; Disease Models, Animal; Fatty Liver; Hyperinsulinism; Hypoglycemic Agents; Insulin Resistance; Liver; Male; Methionine; Obesity; Pioglitazone; Plasminogen Activator Inhibitor 1; PPAR gamma; Rats; Rats, Inbred OLETF; Rats, Long-Evans; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Thiazolidinediones; Transforming Growth Factor beta; Up-Regulation

Hyperinsulinemia has been implicated in the development of diabetic nephropathy. In the present study we compared the renoprotective effects of the thiazolidinedione, pioglitazone (PGZ), to that of insulin in a hypertensive, obese, type II diabetic rat model. PGZ aggravated obesity and gave less glycemic control than insulin. However, renoprotection was markedly better with PZG compared to insulin as shown by lower proteinuria, improved renal function, and less histological evidence of diabetic glomerular and tubulointerstitial lesions. PZG and insulin both reduced renal accumulation of pentosidine and oxidative stress to a similar extent. In contrast, PGZ but not insulin suppressed enhanced transforming growth factor-beta (TGF-beta) expression. We further confirmed in cultured rat proximal tubular cells that insulin enhanced TGF-beta mRNA expression and protein production. Our results identify hyperinsulinemia and the attendant increase of TGF-beta expression as potential therapeutic targets in diabetes independent of glycemic control. This confirms prior clinical evidence that PZG provides renoprotection in obese, diabetic patients with nephropathy.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Glycation End Products, Advanced; Hyperinsulinism; Hypertension, Renal; Hypoglycemic Agents; Insulin; Kidney; Male; Obesity; Oxidative Stress; Pioglitazone; Proteinuria; Rats; Rats, Inbred SHR; Rats, Inbred WKY; RNA, Messenger; Thiazolidinediones; Transforming Growth Factor beta

Platelets are rich sources of growth factors and enzymes that are implicated in a number of diseases including obesity, atherosclerosis, heart disease, syndrome X, liver and kidney diseases and certain types of cancers. In this research we investigated, if platelets in Zucker obese rats differ from their lean counterparts with respect to the levels of TGF-beta and COX isoforms, implicated in the pathogenesis of chronic diseases. In addition, we investigated if energy intake of the animals affects the platelet physiology. Platelets were isolated from obese and lean rats bearing preneoplastic lesions in their colon. Prior to platelet isolation these rats were fed either ad libitum (Ob or Ln) or energy restricted (Ob-ER or Ln-ER) diets for 8 weeks (n = 8/group). The levels of TGF-beta1/-beta2 and COX-1/-2 proteins in platelets were analyzed by Western blot. The platelets of the Ob rats had significantly higher levels of TGF-beta1, COX-1/-2 (p < 0.001) than did the platelets of the Ln rats and were not affected by moderate energy restriction. There were no significant differences in the protein expression of platelet TGF-beta2 among any of the groups. These results demonstrate that cytokines and candidates playing a role in the pathogenesis of chronic diseases, such as TGF-beta1 and COX-1/-2, are over-expressed in platelets of Zucker obese rats by comparison to their lean counterparts. These findings also demonstrate that the genotype of the animals exerts a significant effect on the biochemical composition of the platelets and could contribute to the pathogenesis of colon cancer and other metabolic abnormalities associated with obesity.

Topics: Animals; Blood Platelets; Colonic Neoplasms; Cyclooxygenase 1; Cyclooxygenase 2; Diet, Carbohydrate-Restricted; Energy Intake; Female; Isoenzymes; Membrane Proteins; Obesity; Precancerous Conditions; Rats; Rats, Zucker; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2

Topics: Cardiovascular Diseases; Diet; Forkhead Transcription Factors; Gene Expression Regulation; Humans; Insulin Resistance; Obesity; Oxidative Stress; Plasminogen Activator Inhibitor 1; Stroke; Transforming Growth Factor beta; Transforming Growth Factor beta1

One of the mechanisms involved in the progression of diabetic nephropathy, the most common cause of end-stage renal failure, is angiogenic phenomenon associated with the increase of angiogenic factors such as vascular endothelial growth factor (VEGF)-A and angiopoietin (Ang)-2, an antagonist of Ang-1. In the present study, we examined the therapeutic efficacy of 2-(8-hydroxy-6-methoxy-1-oxo-1H-2-benzopyran-3-yl) propionic acid (NM-3), a small molecule isocoumarin with antiangiogenic activity, using diabetic db/db mice, a model of obese type 2 diabetes. Increases in kidney weight, glomerular volume, creatinine clearance, urinary albumin excretion, total mesangial fraction, glomerular type IV collagen, glomerular endothelial area (CD31(+)), and monocyte/macrophage accumulation (F4/80(+)) observed in control db/db mice were significantly suppressed by daily intraperitoneal injection of NM-3 (100 mg/kg, for 8 weeks). Increases in renal expression of VEGF-A, Ang-2, fibrogenic factor transforming growth factor (TGF)-beta1, and chemokine monocyte chemoattractant protein-1 but not tumor necrosis factor-alpha were also inhibited by NM-3 in db/db mice. Furthermore, decreases of nephrin mRNA and protein levels in db/db mice were recovered by NM-3. In addition, treatment of db/db mice with NM-3 did not affect body weight, blood glucose, serum insulin, or food consumption. NM-3 significantly suppressed the increase of VEGF induced by high glucose in cultured podocytes and also suppressed the increase of VEGF and TGF-beta induced by high glucose in cultured mesangial cells. Taken together, these results demonstrate the potential use of NM-3 as a novel therapeutic agent for renal alterations in type 2 diabetes.

Topics: Angiogenesis Inhibitors; Animals; Chemokine CCL2; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Heart; Insulin; Interleukin-6; Isocoumarins; Kidney; Liver; Mice; Obesity; Organ Size; Placebos; Polymerase Chain Reaction; Transforming Growth Factor beta

A pluripotent cell line, C3H10T1/2, is induced to undergo adipogenesis by a mixture of factors that includes a glucocorticoid such as dexamethasone. We found that expression of myostatin (MSTN), a TGF-beta family member extensively studied in muscle, was induced by dexamethasone under those differentiation conditions. Moreover, MSTN could substitute for dexamethasone in the adipogenesis mixture. However, the adipocytes induced by MSTN in both cell culture and transgenic mice were small and expressed markers characteristic of immature adipocytes. These adipocytes exhibited cell-autonomous increases in insulin sensitivity and glucose oxidation. In mice, these effects produced elevated systemic insulin sensitivity and resistance to diet-induced obesity. Modulation of the final stages of adipogenesis may provide a novel approach to understanding and treating metabolic disease.

Topics: Adipocytes; Adipogenesis; Adipose Tissue; Animals; Cell Differentiation; Cell Line; Dexamethasone; Diet; Glucose; Insulin; Male; Mice; Mice, Transgenic; Myostatin; Obesity; Oxidation-Reduction; Transforming Growth Factor beta

There is a finely tuned interplay between immune and neuroendocrine systems. Metabolic disturbances like obesity will have serious consequences on immunity both at the cellular and at the cytokine expression levels. Our in vivo results confirm the immune deficiency of ob/ob mice, leptin deficient and massively obese, characterized by a reduced Ag-specific T cell proliferation after keyhole limpet hemocyanin immunization. In this report, we show that dendritic cells (DCs), major APCs involved in T lymphocyte priming, are affected in obese mice. Both their function and their steady-state number are disturbed. We demonstrate that DCs from ob/ob mice are less potent in stimulation of allogenic T cells in vitro. This impaired functionality is not associated with altered expression of phenotypic markers but with the secretion of immunosuppressive cytokines such as TGF-beta. Moreover, we show increased in vivo steady-state number of epidermal DCs in ob/ob mice, which is not due to a migratory defect. The ob/ob mice are characterized by the absence of functional leptin, a key adipokine linking nutrition, metabolism, and immune functions. Interestingly, intradermal injection of leptin is able to restore epidermal DC number in obese mice. Thus, DCs might be directly sensitive to metabolic disturbances, providing a partial explanation of the immunodeficiency associated with obesity.

Topics: Animals; Cell Movement; Cytokines; Dendritic Cells; Epidermis; Female; Immunologic Deficiency Syndromes; Langerhans Cells; Leptin; Mice; Mice, Obese; Obesity; T-Lymphocytes; Transforming Growth Factor beta

To determine whether angiotensin converting enzyme inhibition by perindopril can reduce cardiac transforming growth factor beta1 (TGFbeta1) and plasminogen activator inhibitor 1 (PAI-1) and therefore control collagen accumulation in an animal model with the metabolic syndrome such as the obese Zucker rat (OZR).. Male OZR (group 1, n = 10); OZR treated with perindopril (group 2, n = 10); and lean Zucker rats (group 3, n = 10).. During six months, group 2 received 3 mg/kg/day of perindopril orally and group 1 and group 3 were given a vehicle. Hearts were processed for pathology studies including immunohistochemical analysis with antibodies to PAI-1, TGFbeta1, collagen type I, and collagen type III.. Group 2 had lower blood pressure (126.7 (2) v 148.6 (2.7) mm Hg, p < 0.01) than untreated OZR and had decreased cardiac PAI-1 (3.6 (0.4) v 13.5 (1.7)% of positive area/field, p < 0.01), TGFbeta1 in myocytes (0.13 (0.1) v 9.14 (4.7)%/area, p < 0.01) and in interstitium (19.8 (6.8) v 178.9 (27.4) positive cells/area, p < 0.01), collagen I (3 (0.8) v 13.3 (1)%/area, p < 0.01), collagen III (5 (0.6) v 9.5 (0.9)%/area, p < 0.01), and collagen I to collagen III ratio (0.59 (0.13) v 1.40 (0.15) p < 0.01) compared with untreated OZR.. These results suggest that perindopril reduces cardiac PAI-1 and TGFbeta1 and ameliorates cardiac fibrosis in a rat model with multiple cardiovascular risk factors.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Collagen; Disease Models, Animal; Male; Metabolic Syndrome; Myocardium; Obesity; Organ Size; Perindopril; Plasminogen Activator Inhibitor 1; Rats; Rats, Zucker; Transforming Growth Factor beta; Transforming Growth Factor beta1

Recent studies have demonstrated that synthetic protease inhibitors could ameliorate the progression of pancreatic fibrosis in some animal models. Since oral administration of protease inhibitors increases the plasma cholecystokinin (CCK) levels and causes hypertrophy of the pancreas in rats, there is a possibility that the protease inhibitor inhibits fibrosis in the pancreas via endogenous CCK release. We examined the effects of camostat, a synthetic protease inhibitor, on histopathologic changes in Otsuka Long-Evans Tokushima Fatty (OLETF) rat that has genetically no expression of CCK-1 receptor and displays inflammation and degeneration of the pancreas.. Three groups of OLETF rats received a camostat-rich diet (200 mg/100 g normal diet) from 12 to 28 weeks of age or from 12 or 28 weeks of age to the age of 72 weeks, while the fourth group received standard rat diet.. Pancreatic wet weight and pancreatic contents of protein, DNA, amylase, lipase, and trypsin in camostat-treated rats were significantly higher than those in the untreated control rats. Immunohistochemical studies of the pancreas showed that expressions of interleukin-1beta, interleukin-6, tumor necrosis factor-alpha, and alpha-smooth muscle actin in camostat-treated rats were greatly suppressed compared with those in the untreated control rats. Atrophy and fibrosis in the pancreas observed in the untreated control rats were not found in camostat-fed rats.. The results of the present study suggest that camostat greatly inhibits pancreatic inflammation and prevents and reverses fibrosis and atrophy of the pancreas in the genetically obese and CCK-1 receptor-deficient OLETF rats.

Topics: Actins; Amylases; Animals; Atrophy; Eating; Esters; Fibrosis; Gabexate; Guanidines; Interleukin-6; Lipase; Male; Obesity; Organ Size; Pancreas; Pancreatitis, Chronic; Protease Inhibitors; Rats; Rats, Inbred OLETF; Receptor, Cholecystokinin A; Transforming Growth Factor beta; Trypsin; Tumor Necrosis Factor-alpha

Accumulating clinical evidence indicates increased aortic stiffness, an independent risk factor for cardiovascular and all-cause mortality, in type 2 diabetic and glucose-intolerant individuals. The present study sought to determine whether increased mechanical stiffness, an altered extracellular matrix, and a profibrotic gene expression profile could be observed in the aorta of the insulin-resistant Zucker fa/fa rat. Mechanical testing of Zucker fa/fa aortas showed increased vascular stiffness in longitudinal and circumferential directions compared with Zucker lean controls. Unequal elevations in developed strain favoring the longitudinal direction resulted in a loss of anisotropy. Real-time quantitative PCR and immunohistochemistry revealed increased expression of fibronectin and collagen IV alpha 3 in the Zucker fa/fa aorta. In addition, expression of transforming growth factor-beta and several Smad proteins was increased in vessels from insulin-resistant animals. In rat vascular smooth muscle cells, 12-18 h of exposure to insulin (100 nmol/l) enhanced transforming growth factor-beta1 mRNA expression, implicating a role for hyperinsulinemia in vascular stiffness. Thus there is mechanical, structural, and molecular evidence of arteriosclerosis in the Zucker fa/fa rat at the glucose-intolerant, hyperinsulinemic stage.

Topics: Animals; Aorta; Elasticity; Extracellular Matrix Proteins; Insulin Resistance; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Obesity; Rats; Rats, Zucker; Signal Transduction; Tissue Culture Techniques; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

Despite the strides made toward understanding cardiac abnormalities in obesity-induced hypertension, the composition and concentration of cardiac extracellular matrix (ECM) components resulting from diet-induced obesity are largely unknown. Previous studies from our laboratory have demonstrated differential expression of collagens, growth factors, and homocysteine (Hcy) in pressure overload models of cardiac hypertrophy. The hypothesis of the present study was that left ventricular hypertrophy (LVH) from the combined pressure and volume overload of obesity induced cardiac fibrosis in part by increasing Hcy, increasing transforming growth factor-beta1 (TGF-beta1), and decreasing decorin. Using the rabbit model, we examined the changes in cardiac collagen accumulation, plasma Hcy, left ventricular (LV) TGF-beta1, and LV decorin after 12 weeks of developing obesity. Cardiac fibrosis was analyzed by trichrome stain for collagens. Total collagens types I and III, TGF-beta1, and decorin were analyzed in tissue homogenates by immunoblots and quantitated with a densitometer. After 12 weeks, rabbits eating a high-fat diet had greater body weight (5.38 +/- 0.3 kg v 3.73 +/- 0.6 kg) and greater LV weight (5.08 +/- 0.05 g v 3.86 +/- 0.17 g) compared with lean rabbits. Heart rate was also significantly higher in obese than in lean rabbits (221 +/- 8 v 173 +/- 5 beats/min). Plasma concentrations of circulating Hcy were 16.9 +/- 2.4 micromol/L and 24.3 +/- 1.8 micromol/L in lean and obese rabbits, respectively. Compared with lean rabbits, obese rabbits had increased interstitial and perivascular collagen, a 4-fold increase in the medial/lumen ratio of coronary vessels, a 1.75-fold increase in cardiac collagen I, and a 1.5-fold increase in cardiac collagen III levels. Levels of TGF-beta1 were increased 1.75-fold, whereas decorin levels were significantly reduced in obese compared with lean rabbits. In conclusion, a high-fat diet, even over a period as short as 12 weeks, causes fibrosis in coronary vessels as well as accumulation of collagen in the cardiac interstitium. The accumulation of cardiac collagen was associated with induction of Hcy and TGF-beta1 and with suppression of decorin.

Topics: Animals; Collagen; Coronary Vessels; Extracellular Matrix; Female; Homocysteine; Hypertrophy; Multiple Organ Failure; Myocardium; Obesity; Rabbits; Transforming Growth Factor beta; Transforming Growth Factor beta1

This study has been designed to evaluate the relationship among transforming growth factor beta1 (TGFbeta1) and some measurements of diastolic function in a population of hypertensive subjects with normal left ventricular ejection fraction. We studied 67 hypertensive outpatients who according to their BMI levels were subdivided into three groups: lean (L), overweight (OW) and obese (OB) hypertensives (HT). Circulating TGFbeta1 and M- and B-mode echocardiography was determined. All hypertensives were further subgrouped, according to European Society of Cardiology Guidelines, into two subsets of patients with normal diastolic function or with diastolic dysfunction. Prevalence of left ventricular hypertrophy (LVH) was determined in all the groups. TGFbeta1, left ventricular mass (LVM), LVM/h(2.7), E-wave deceleration time and isovolumic relaxation time (IVRT) were significantly (P < 0.005) higher and E/A velocity ratio was significantly (P < 0.05) lower in OW-HT and OB-HT than in L-HT. Prevalence of LVH was significantly higher (P < 0.03) in group OB-HT than in L-HT. TGFbeta1 (P < 0.004), LVM/h(2.7) (P < 0.001) and prevalence of LVH were (P < 0.01) significantly higher in hypertensives with diastolic dysfunction than hypertensives with normal diastolic function. TGFbeta1 levels were positively correlated with BMI (r = 0.60; P < 0.0001), LVM/h(2.7) (r = 0.28; P < 0.03), IVRT (r = 0.30; P < 0.02) and negatively with E/A ratio (r = -0.38; P < 0.002) in all HT. Multiple regression analysis indicated that TGFbeta1, BMI and IVRT were independently related to E/A ratio explaining 71% of its variability (r = 0.84; P < 0.0001). This relationship was independent of LVH, age and HR suggesting that TGFbeta1 overproduction may be considered a pathophysiological mechanism in the development of left ventricular filling abnormalities in obesity-associated hypertension.

Topics: Adult; Aged; Biomarkers; Diastole; Echocardiography; Enzyme-Linked Immunosorbent Assay; Female; Heart Ventricles; Humans; Hypertension; Hypertrophy, Left Ventricular; Male; Middle Aged; Myocardial Contraction; Obesity; Regression Analysis; Risk Factors; Stroke Volume; Transforming Growth Factor beta; Transforming Growth Factor beta1; Ventricular Dysfunction, Left

A key goal of biomedical research is to elucidate the complex network of gene interactions underlying complex traits such as common human diseases. Here we detail a multistep procedure for identifying potential key drivers of complex traits that integrates DNA-variation and gene-expression data with other complex trait data in segregating mouse populations. Ordering gene expression traits relative to one another and relative to other complex traits is achieved by systematically testing whether variations in DNA that lead to variations in relative transcript abundances statistically support an independent, causative or reactive function relative to the complex traits under consideration. We show that this approach can predict transcriptional responses to single gene-perturbation experiments using gene-expression data in the context of a segregating mouse population. We also demonstrate the utility of this approach by identifying and experimentally validating the involvement of three new genes in susceptibility to obesity.

Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Animals; DNA-Binding Proteins; Female; Gene Expression; Gene Expression Profiling; Genetic Predisposition to Disease; Genome; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Models, Genetic; Obesity; Quantitative Trait Loci; Receptors, Complement; Repressor Proteins; Transforming Growth Factor beta; Transforming Growth Factor beta2

Diabetic kidney disease has been associated with the presence of lipid deposits, but the mechanisms for the lipid accumulation have not been fully determined. In the present study, we found that db/db mice on the FVB genetic background with loss-of-function mutation of the leptin receptor (FVB-Lepr(db) mice or FVBdb/db) develop severe diabetic nephropathy, including glomerulosclerosis, tubulointerstitial fibrosis, increased expression of type IV collagen and fibronectin, and proteinuria, which is associated with increased renal mRNA abundance of transforming growth factor-beta, plasminogen activator inhibitor-1, and vascular endothelial growth factor. Electron microscopy demonstrates increases in glomerular basement membrane thickness and foot process (podocyte) length. We found that there is a marked increase in neutral lipid deposits in glomeruli and tubules by oil red O staining and biochemical analysis for cholesterol and triglycerides. We also detected a significant increase in the renal expression of adipocyte differentiation-related protein (adipophilin), a marker of cytoplasmic lipid droplets. We examined the expression of sterol regulatory element-binding protein (SREBP)-1 and -2, transcriptional factors that play an important role in the regulation of fatty acid, triglyceride, and cholesterol synthesis. We found significant increases in SREBP-1 and -2 protein levels in nuclear extracts from the kidneys of FVBdb/db mice, with increases in the mRNA abundance of acetyl-CoA carboxylase, fatty acid synthase, and 3-hydroxy-3-methylglutaryl-CoA reductase, which mediates the increase in renal triglyceride and cholesterol content. Our results indicate that in FVBdb/db mice, renal triglyceride and cholesterol accumulation is mediated by increased activity of SREBP-1 and -2. Based on our previous results with transgenic mice overexpressing SREBP-1 in the kidney, we propose that increased expression of SREBPs plays an important role in causing renal lipid accumulation, glomerulosclerosis, tubulointerstitial fibrosis, and proteinuria in mice with type 2 diabetes.

Topics: Animals; CCAAT-Enhancer-Binding Proteins; Cell Nucleus; Cholesterol; Diabetes Mellitus, Type 2; Diabetic Nephropathies; DNA-Binding Proteins; Female; Gene Expression Regulation; Hyperlipidemias; Kidney; Lipid Metabolism; Mice; Mutation; Obesity; Plasminogen Activator Inhibitor 1; Proteinuria; Receptors, Cell Surface; Receptors, Leptin; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Sterol Regulatory Element Binding Protein 2; Transcription Factors; Transforming Growth Factor beta; Triglycerides; Vascular Endothelial Growth Factor A

Topics: Diabetes Mellitus; Fibrosis; Humans; Hypertension; Obesity; Risk Factors; Schistosomiasis; Smoking; Somatostatin; Transforming Growth Factor beta; Transforming Growth Factor beta1

Obesity and insulin resistance cause serious consequences to human health. To study effects of skeletal muscle growth on obesity prevention, we focused on a key gene of skeletal muscle named myostatin, which plays an inhibitory role in muscle growth and development. We generated transgenic mice through muscle-specific expression of the cDNA sequence (5'-region 886 nucleotides) encoding for the propeptide of myostatin. The transgene effectively depressed myostatin function. Transgenic mice showed dramatic growth and muscle mass by 9 weeks of age. Here we reported that individual major muscles of transgenic mice were 45-115% heavier than those of wild-type mice, maintained normal blood glucose, insulin sensitivity, and fat mass after a 2-month regimen with a high-fat diet (45% kcal fat). In contrast, high-fat diet induced wild-type mice with 170-214% more fat mass than transgenic mice and developed impaired glucose tolerance and insulin resistance. Insulin signaling, measured by Akt phosphorylation, was significantly elevated by 144% in transgenic mice over wild-type mice fed a high-fat diet. Interestingly, high-fat diet significantly increased adiponectin secretion while blood insulin, resistin, and leptin levels remained normal in the transgenic mice. The results suggest that disruption of myostatin function by its propeptide favours dietary fat utilization for muscle growth and maintenance. An increased secretion of adiponectin may promote energy partition toward skeletal muscles, suggesting that a beneficial interaction between muscle and adipose tissue play a role in preventing obesity and insulin resistance.

Topics: Adipose Tissue; Animals; Dietary Fats; Gene Expression; Hormones; Insulin Resistance; Mice; Mice, Transgenic; Muscle, Skeletal; Myostatin; Obesity; Peptides; Protein Precursors; Transforming Growth Factor beta

In this study, we evaluated whether a combination of an angiotensin-converting enzyme (ACE) inhibitor, benazepril (B), with an angiotensin type I receptor antagonist (AT1RA), irbesartan (I), is as effective or more than drugs as monotherapy in controlling renal damage in obese Zucker rats (OZR), a model of metabolic syndrome.. During six months, G1 (OZR receiving no treatment); G2 (OZR with B 10 mg/kg/day); G3 (OZR with I 50mg/kg/day); and G4 (OZR with B 5mg/kg/day + I 25 mg/kg/day). Kidneys were processed for light microscopy (LM) and immunohistochemistry, including antibodies against interstitial alpha-smooth-muscle-actin (alpha-SMA), plasminogen activator inhibitor-1 (PAI-1), transforming growth factor-beta(1)(TGF-beta 1), and collagen (COL) I, III, and IV.. All treated groups presented similar reduction in blood pressure compared with untreated OZR. However, animals from G4 (B + I) showed better control on proteinuria together with a higher creatinine clearance. Additionally, G4 showed a significant (P < 0.05) lower kidney weight; smaller glomerular area; lower glomerulosclerosis score; lower percentage of tubular atrophy, interstitial fibrosis, and interstitial alpha-SMA; lower tubular PAI-1 score; lower percentage of COL I, III, and IV in renal interstitium; and lower wall/lumen ratio in renal vessels, when compared with the other groups. OZR treated with B and/or I showed a better outcome (P < 0.01) in the carbohydrate and lipid metabolism in comparison with untreated OZR.. These results suggest that combined therapy using B and I is more effective than therapy with either drug at monotherapy for controlling renal damage in this animal model. In addition, data presented here reaffirm the benefit of interacting against renin-angiotensin-system (RAS) in the metabolic syndrome.

Topics: Actins; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzazepines; Biphenyl Compounds; Collagen; Drug Therapy, Combination; Irbesartan; Kidney; Male; Metabolic Syndrome; Obesity; Organ Size; Plasminogen Activator Inhibitor 1; Rats; Rats, Zucker; Tetrazoles; Transforming Growth Factor beta; Transforming Growth Factor beta1

The adequacy of association studies for complex diseases depends critically on the existence of linkage disequilibrium (LD) between functional alleles and surrounding SNP markers.. We examined the patterns of LD and haplotype distribution in eight candidate genes for osteoporosis and/or obesity using 31 SNPs in 1,873 subjects. These eight genes are apolipoprotein E (APOE), type I collagen alpha1 (COL1A1), estrogen receptor-alpha (ER-alpha), leptin receptor (LEPR), parathyroid hormone (PTH)/PTH-related peptide receptor type 1 (PTHR1), transforming growth factor-beta1 (TGF-beta1), uncoupling protein 3 (UCP3), and vitamin D (1,25-dihydroxyvitamin D3) receptor (VDR). Yin yang haplotypes, two high-frequency haplotypes composed of completely mismatching SNP alleles, were examined. To quantify LD patterns, two common measures of LD, D' and r2, were calculated for the SNPs within the genes. The haplotype distribution varied in the different genes. Yin yang haplotypes were observed only in PTHR1 and UCP3. D' ranged from 0.020 to 1.000 with the average of 0.475, whereas the average r2 was 0.158 (ranging from 0.000 to 0.883). A decay of LD was observed as the intermarker distance increased, however, there was a great difference in LD characteristics of different genes or even in different regions within gene.. The differences in haplotype distributions and LD patterns among the genes underscore the importance of characterizing genomic regions of interest prior to association studies.

Topics: Apolipoproteins E; Carrier Proteins; Collagen Type I; Collagen Type I, alpha 1 Chain; Estrogen Receptor alpha; Family Health; Female; Gene Frequency; Genetic Predisposition to Disease; Genotype; Haplotypes; Humans; Ion Channels; Linkage Disequilibrium; Male; Mitochondrial Proteins; Obesity; Osteoporosis; Polymorphism, Single Nucleotide; Receptor, Parathyroid Hormone, Type 1; Receptors, Calcitriol; Receptors, Cell Surface; Receptors, Estrogen; Receptors, Leptin; Statistics as Topic; Transforming Growth Factor beta; Transforming Growth Factor beta1; Uncoupling Protein 3

Myostatin is a member of transforming growth factor-beta superfamily that plays an important inhibitory role during muscle development; in fact mutations of myostatin gene result in a hypermuscular phenotype. Moreover myostatin-deficient mice have a significant reduction in fat depots and a depression of adipogenesis. Little is known about myostatin function in muscle growth regulation in humans and in particular during caloric restriction. In the present work we quantified by real-time RT-PCR myostatin expression in muscle biopsies of a group of morbidly obese patients before and after weight loss obtained by biliopancreatic diversion (BPD). The patients reduced body weight by 38.9%, mostly due to fat-mass loss, showing also a significant reduction in the 24-hour EE as assessed by the respiratory chamber. Myostatin mRNA levels result clearly decreased after weight loss, suggesting a role in counteracting the progressive decline of muscle mass after BPD. Myostatin may provide therefore another mechanistic explanation for the control of energy partitioning between protein and fat, working against muscle wasting. Our data suggest that myostatin might represent an important regulator of skeletal muscle size also in conditions of food restriction in obese subjects.

Topics: Body Composition; Diet, Reducing; Energy Metabolism; Gene Expression; Humans; Muscle, Skeletal; Myostatin; Nitrogen; Obesity; Transforming Growth Factor beta; Weight Loss

The molecular mechanisms linking abnormal kidney function and obesity hypertension are poorly understood. This study compared gene expression profiles in the kidney medulla and cortex of obese and lean dogs.. Lean dogs (N= 4) were fed a standard kennel ration and obese dogs (N= 4) were fed the standard diet plus 0.5 to 0.9 kg of cooked beef fat per day for 10 weeks. The dogs were instrumented for continuous monitoring of mean arterial pressure (MAP), heart rate, glomerular filtration rate (GFR), and effective renal plasma flow (RPF). The relative mRNA levels of 375 genes in renal cortex and medulla were determined simultaneously using cDNA membrane arrays (R&D Systems).. The high fat diet increased body weight by 57% and MAP increased by 24 mm Hg (112 +/- 1 mm Hg vs. 88 +/- 3 mm Hg) in obese compared to lean dogs. In obese dogs, expression of 11 and 13 genes changed significantly (N= 4; P < 0.05) in the renal medulla and the cortex, respectively, relative to the lean dogs. Differences in renal gene expression profiles between lean and obese dogs were closely related to functional pathways, including those associated with sympathetic activation, inflammatory response, matrix formation, angiogenesis, endothelial dysfunction, attenuated actions of leptin, and attenuated cell survival.. A high fat diet in dogs is associated with marked changes in renal gene expression profiles that provide potential molecular links to pathways associated with altered renal function and structure in obesity hypertension.

Topics: Animals; Blood Pressure; Blotting, Northern; Body Weight; Cytokines; Dogs; Glomerular Filtration Rate; Heart Rate; Hypertension, Renal; Kidney Cortex; Kidney Medulla; Male; Obesity; Oligonucleotide Array Sequence Analysis; Organ Size; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vascular Endothelial Growth Factor A

Obesity and insulin resistance confer increased risk for accelerated coronary disease and cardiomyopathic phenomena. We have previously shown that inhibition of angiotensin-converting enzyme (ACE) prevents coronary perimicrovascular fibrosis in genetically obese mice that develop insulin resistance. This study was performed to elucidate mechanism(s) implicated and to determine the effects of attenuation of angiotensin II (Ang) II. Genetically obese ob/ob mice were given ACE inhibitor (temocapril) or Ang II type 1 (AT(1)) receptor blocker (olmesartan) from 10 to 20 weeks. Cardiac expressions of plasminogen activator inhibitor (PAI)-1, the major physiologic inhibitor of fibrinolysis, and transforming growth factor (TGF)-beta(1), a prototypic profibrotic molecule, were determined and extent of perivascular coronary fibrosis was measured. Twenty-week-old obese mice exhibited increased plasma levels of PAI-1 and TGF-beta(1) compared with the values in lean counterpart. Perivascular coronary fibrosis in arterioles and small arteries was evident in obese mice that also showed increased left ventricular collagen as measured by hydroxyproline assay. Immunohistochemistry confirmed the deposition of perivascular type 1 collagen. Markedly increased PAI-1 and TGF-beta were seen immunohistochemically in coronary vascular wall and confirmed by western blotting. When obese mice were treated with temocapril or olmesartan from 10 to 20 weeks, both were equally effective and prevented increases in perivascular fibrosis, plasma PAI-1 and TGF-beta(1), left ventricular collagen and mural immunoreactivity for PAI-1, TGF-beta and collagen type 1. The c-Jun NH(2)-terminal kinase (JNK) activity was elevated in the left ventricle of obese mice (western) and blocked by temocapril and olmesartan. Ang II-mediated upregulation of PAI-1 and TGF-beta(1) with collagen deposition may explain the mechanism of perivascular fibrosis in obese mice. ACE inhibition and blockade of AT(1) receptor may prevent coronary perivascular fibrosis and collagen deposition even before development of overt diabetes. JNK activation may be a mediator of obesity-related cardiac dysfunction and a potential therapeutic target.

Topics: Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Glucose; Collagen Type I; Coronary Disease; Coronary Vessels; Fibrosis; Heart Ventricles; Imidazoles; Insulin; Insulin Resistance; JNK Mitogen-Activated Protein Kinases; Male; Matrix Metalloproteinase 9; Mice; Mice, Obese; Obesity; Olmesartan Medoxomil; Phosphorylation; Plasminogen Activator Inhibitor 1; Tetrazoles; Thiazepines; Transforming Growth Factor beta

Plasminogen activator inhibitor type-1 (PAI-1) plays a central role in fibrolysis and has recently been hypothesized to influence components of the insulin resistance syndrome. We consider whether the 4G/5G polymorphism influences components of insulin resistance and obesity solely through PAI-1 protein levels or also though a secondary pathway. In addition, we explore whether transforming growth factor (TGF-beta1), a key regulator of PAI-1 expression, modifies the influence of the PAI-1 4G/5G polymorphism on these traits.. The Insulin Resistance and Atherosclerosis (IRAS) Family Study genotyped 287 African American (18 pedigrees) and 811 Hispanic American (45 pedigrees) individuals for the 4G/5G PAI-1 and two TGF-beta1 polymorphisms (R25P, C-509T). Individuals were recruited from three clinical centers located in San Antonio (urban Hispanic), San Luis Valley (rural Hispanic) and Los Angeles (African American). The presence of the 4G PAI-1 allele was positively associated with PAI-1 protein level (combined sample p < 0.0001). Hispanic Americans average 65% higher PAI-1 protein levels than African Americans (p < 0.0001). Consistently across ethnic groups, increased PAI-1 protein levels were associated with increased insulin resistance and overall and central obesity (p value < 0.0001, combined sample). Adjusting for PAI-1 protein levels, there was evidence of an association of PAI-1 genotype (4G) with insulin sensitivity (p < 0.002) and subcutaneous fat (p < 0.01). These associations were not influenced by TGF-beta1 genotypes.. PAI-1 protein is a strong correlate of insulin resistance (IR) and obesity in Hispanics and African Americans. However, PAI-1 4G/5G polymorphism appears to influence insulin resistance and obesity beyond its direct influence on serum PAI-1 protein levels.

Topics: Black or African American; Body Composition; DNA Primers; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Genetic Linkage; Genotype; Glucose Tolerance Test; Hispanic or Latino; Humans; Insulin; Insulin Resistance; Linkage Disequilibrium; Models, Genetic; Obesity; Pedigree; Phenotype; Plasminogen Activator Inhibitor 1; Polymorphism, Genetic; Quantitative Trait Loci; Radioimmunoassay; Tomography, X-Ray Computed; Transforming Growth Factor beta; Transforming Growth Factor beta1; United States

Reduction of renal mass is frequently associated with progressive loss of kidney function. We examined the effects of hyperlipidemia on renal pathology and mediators of tissue damage in B6.ROP Os/+ mice, a model of reduced renal mass.. C57BL/6 control mice and B6.ROP Os/+ mice were fed normal rodent chow or a high fat, high cholesterol (HFHC) diet for 12 weeks. Kidney function and renal pathology were assessed.. Hyperlipidemia led to a decline in kidney function in C57BL/6 mice. Renal pathology was characterized by an increase in glomerular matrix and cellularity, glomerular and tubulointerstitial macrophage influx, and increased tubular epithelial cell turnover. Chow-fed B6.ROP Os/+ animals demonstrated glomerular hypertrophy with an increase in mesangial matrix and cellularity that was characterized by macrophage influx and increased proliferation. The tubulointerstitium showed increased macrophages as well as tubular atrophy and dilation. Renal pathology was accompanied by an increase in blood urea nitrogen (BUN) and proteinuria. Hyperlipidemia in B6.ROP Os/+ mice resulted in increased plasma BUN compared to chow-fed B6.ROP Os/+ animals and aggravated renal pathology by further increasing glomerular matrix and glomerular hypercellularity. Glomerular hypercellularity was associated with increased expression of platelet-derived growth factor-B (PDGF B) and its receptor beta. Glomerular transforming growth factor-beta (TGF-beta) mRNA expression was increased in B6.ROP Os/+ mice, hyperlipidemic C57BL/6 mice and hyperlipidemic B6.ROP Os/+ animals compared to controls and correlated with the amount of mesangial matrix.. This study demonstrates that hyperlipidemia worsens renal pathology in B6.ROP Os/+ mice with a decline in renal function mediated at least in part through increased renal expression of the cytokines PDGF B and TGF-beta.

Topics: Animals; Chemokine CCL2; Extracellular Matrix; Female; Glomerular Mesangium; Hyperglycemia; Hyperlipidemias; Hypertrophy; Insulin Resistance; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Microscopy, Electron; Obesity; Proto-Oncogene Proteins c-sis; RNA, Messenger; Transforming Growth Factor beta

Leptin, a product of the obese (ob) gene is present in activated stellate cells. This study investigated whether leptin is essential for the development of hepatic fibrosis caused by various agents.. Control and ob/ob mice were infected with Schistosoma mansoni or were administered chronic carbon tetrachloride to cause hepatic fibrosis.. Fibrosis developed in both ob/ob and control mice. However, the amount of histologically detectable fibrosis and the increase in liver hydroxyproline content was significantly greater in both models of fibrosis for treated controls than for treated ob/ob mice. Fibrosis was associated with higher secretion of TGFbeta1 from spleen cells of treated control than treated ob/ob mice. Chronic leptin administration in ob/ob mice infected with Schistosoma mansoni resulted in an increase in the amount of fibrosis caused by Schistosoma mansoni, eliminating any significant differences in the amount of fibrosis between infected ob/ob mice and control mice. It also eliminated any significant difference in TGFbeta1 secretion between the infected ob/ob and infected control mice.. This study shows that leptin deficiency decreases but does not eliminate hepatic fibrosis produced by Schistosoma mansoni and carbon tetrachloride administration. The effect of leptin in potentiating fibrogenesis is most likely mediated by TGFbeta1.

Topics: Animals; Carbon Tetrachloride; Cytokines; Drug Administration Schedule; Leptin; Liver; Liver Cirrhosis, Experimental; Male; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Obesity; Schistosomiasis mansoni; Spleen; Transforming Growth Factor beta; Transforming Growth Factor beta1

In humans, a T-->C transition at nucleotide 29 in the region encoding the signal peptide sequence of the transforming growth factor (TGF)-beta(1), which results in a Leu-->Pro substitution at codon 10, has been associated with myocardial infarction.. In the present study, we genotyped 284 unrelated, nondiabetic Swedish men born in 1944 to assess the impact of the Leu10Pro variant on obesity, including abdominal obesity, and estimates of insulin, glucose and lipid metabolism as well as blood pressure.. The frequency of the Pro10 variant was 38.9% (95% CI 32.2-46.0%), and the distribution of genotypes was in Hardy-Weinberg equilibrium. Data analysis showed that heterozygotes had significantly higher body mass index compared to homozygous carriers to the Leu10 variant. In addition, homozygous carriers of the Leu10 variant had significantly lower abdominal sagittal diameter than both Leu10Pro and Pro10Pro carriers. We also found that heterozygotes had significantly higher fasting insulin values as well as higher HOMA insulin-resistance index in comparison to homozygous carriers of the Leu10. Fasting glucose levels were significantly higher in subjects with the Pro10Pro variant compared to subjects with either the Leu10Leu or Leu10Pro variant.. These findings suggest that the Pro10 allele in the TGF-beta(1) gene pathway might contribute to prevalent diseases such as obesity and type 2 diabetes mellitus.

Topics: Abdomen; Adenine; Blood Glucose; Fasting; Gene Frequency; Genetic Variation; Guanine; Heterozygote; Homozygote; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Polymorphism, Genetic; Transforming Growth Factor beta; Transforming Growth Factor beta1

Human adipose tissue can produce plasminogen activator inhibitor-1 (PAI-1). It has been suggested that high levels of PAI-1 are of importance in enhanced cardiovascular disease observed among obese subjects, especially abdominally obese individuals. In the present study, we investigated the level of mRNA and production of PAI-1 in adipose tissue from two adipose tissue depots (omental vs. subcutaneous). Adipose tissue from both depots was obtained from obese (mean BMI, 46.9 kg/m 2) and non-obese (mean BMI, 23.9 kg/m 2) women. PAI-1 mRNA was measured both in fresh adipose tissue obtained immediately after surgery and after the adipose tissue (fragments) had been incubated for up to 72 h. In immediately frozen adipose tissue, PAI-1 mRNA expression was similar in omental and subcutaneous adipose tissue. No differences between obese and non-obese women were found. However, when adipose tissue fragments were cultured, PAI-1 mRNA and PAI-1 production were significantly higher in omental than in subcutaneous adipose tissue (p < 0.05). In the culture system, the production of PAI-1 in obese subjects was higher than in non-obese subjects in both subcutaneous (p < 0.05) and in omental adipose tissue (p = 0.19). In order to test whether these regional differences observed after incubation of the adipose tissue were due to differences in local accumulation of cytokines that may stimulate PAI-1 by a paracrine or autocrine manner, we investigated the expression of transforming growth factor beta1 (TGF-beta1) mRNA and tumor necrosis factor alpha (TNF-alpha) mRNA and protein. No differences between the two fat depots were found. In conclusion, no differences in PAI-1 expression between omental and subcutaneous adipose tissue were observed in biopsies frozen immediately after removal, but after incubation of adipose tissue (which somehow stimulates PAI-1 production), higher levels of PAI-1 were found in omental adipose tissue than in subcutaneous adipose tissue. Finally, PAI-1 production in adipose tissue from obese women was higher in non-obese women after incubation for 72 h.

Topics: Adipose Tissue; Adult; Body Mass Index; Body Weight; Culture Techniques; Female; Gene Expression; Humans; Interleukin-1; Middle Aged; Obesity; Omentum; Plasminogen Activator Inhibitor 1; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Subcutaneous Tissue; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Several epidemiological studies have supported the concept that high energy intake, obesity, and/or hyperinsulinemia are risk factors for colon cancer. Previously, it was shown that Zucker obese rats are more sensitive to chemically induced colon cancer than their lean counterparts. The present study investigated whether moderate (20-25%) dietary energy restriction (ER) would attenuate colon carcinogenesis in the Zucker obese rat model. Six-week-old Zucker obese (fa/fa) rats and lean (Fa/Fa) rats received s.c. injections of azoxymethane at a dose of 10 mg/kg body weight once weekly for 2 weeks. A week later, obese rats (n = 16) were assigned to an ER diet (Ob-ER group), based on a low-fat AIN-93G semisynthetic diet. The remaining obese and lean rats (n = 16 rats/group) were fed the low-fat diet ad libitum (Ob group and Ln group, respectively). All rats were euthanized after 8 weeks, and their colons were assessed for aberrant crypt foci (ACF; n = 8/group) or for the expression of transforming growth factor (TGF)-beta and cyclooxygenase (COX) isoforms at the protein and mRNA transcript levels (n = 8/group). Ob rats had a higher number of advanced ACF (crypt multiplicity >or=7) than Ln rats. Dietary ER significantly reduced the appearance of advanced ACF in Ob-ER rats without significantly affecting the blood insulin level or body weights. TGF-beta and COX isoforms were differentially expressed in the colonic mucosae of Ob and Ln rats. Dietary ER significantly reduced TGF-beta1/beta2 and COX-1/2 protein expression in obese rats. This study is the first to demonstrate that moderate ER attenuated TGF-beta and COX protein expression and the carcinogenic process in Zucker obese rats. These findings provide insights leading to the proposal that the mechanism(s) underlying the early events of colon carcinogenesis in Zucker obese rats may extend beyond the role of excessive body weight and hyperinsulinemia per se.

Topics: Animals; Azoxymethane; Blood Glucose; Body Weight; Caloric Restriction; Carcinogens; Colonic Neoplasms; Cyclooxygenase 1; Cyclooxygenase 2; Eating; Female; Insulin; Isoenzymes; Lactic Acid; Membrane Proteins; Obesity; Precancerous Conditions; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Zucker; RNA, Messenger; Transforming Growth Factor beta; Triglycerides

Insulin resistance is associated with a low chronic inflammatory state. In this study we investigated the relationship between impaired insulin sensitivity and selected markers of inflammation and thrombin generation in obese healthy women. We examined 32 healthy obese women (body mass index > or = 28), with normal insulin sensitivity (NIS, n = 14) or impaired insulin sensitivity (n = 18), and 10 nonobese women (body mass index < 25). Impaired insulin sensitivity patients had significantly higher levels of C-reactive protein (CRP), TGF-beta 1, plasminogen activator inhibitor-1 (PAI-1), activated factor VII (VIIa), and prothrombin fragment 1 + 2 (F1 + 2) compared with either control subjects or NIS patients. On the other hand, NIS patients had higher CRP, TGF-beta 1, PAI-1, and factor VIIa, but not F1 + 2, levels than controls. Significant inverse correlations were observed between the insulin sensitivity index and TGF-beta 1, CRP, PAI-1, factor VIIa, and F1 + 2 levels. Moreover, significant direct correlations were noted between TGF-beta 1 and CRP, PAI-1, factor VIIa, and F1 + 2 concentrations. Finally, multiple regressions revealed that TGF-beta 1 and the insulin sensitivity index were independently related to F1 + 2. Our results are the first to document an in vivo relationship between insulin sensitivity and coagulative activation in obesity. The elevated TGF-beta 1 levels detected in the obese population may provide a biochemical link between insulin resistance and an increased risk for cardiovascular disease.

Topics: Adult; Biomarkers; Blood Coagulation; C-Reactive Protein; Factor VIIa; Female; Humans; Insulin Resistance; Middle Aged; Obesity; Peptide Fragments; Plasminogen Activator Inhibitor 1; Protein Precursors; Prothrombin; Thrombin; Transforming Growth Factor beta

Topics: Apolipoproteins E; Female; Gene Frequency; Genetic Linkage; Genetic Predisposition to Disease; Haplotypes; Humans; Linkage Disequilibrium; Male; Obesity; Phenotype; Polymorphism, Single Nucleotide; Transforming Growth Factor beta; Transforming Growth Factor beta1

In this study, the relationship between circulating transforming growth factor beta1 (TGFbeta1) and urinary albumin excretion (UAE) has been investigated in non-obese and central obese hypertensive patients.. Fifty-eight consecutive hypertensive outpatients both lean and with central obesity were enrolled and divided in three groups, according to their body mass index (BMI) values. Group A: 16 lean hypertensives (men with BMI < 25 kg/m2 and women with BMI < 24.7 kg/m2); Group B: 16 overweight hypertensives (men with BMI > or = 25 kg/m2 and < 30 kg/m2 and women with BMI > 24.7 kg/m2 and < 27.3 kg/m2); Group C: 26 obese hypertensives (men with BMI > or = 30 kg/m2 and women with BMI > or = 27.3 kg/m2).. In all patients, UAE, by immunonephelometric assay, circulating TGFbeta1 by a solid-phase specific sandwich enzyme-linked immunosorbent assay (ELISA) technique, blood urea nitrogen (BUN) and creatinine, by routine laboratory methods, were determined. In addition, left ventricular telediastolic internal diameter (LVIDd), interventricular septum diastolic (IVSTd), posterior wall thickness (PWT), total and normalized to height2.7 left ventricular mass (LVM, LVM/h2.7), relative wall thickness (RWT) and left ventricular ejection fraction (EF) by M-B Mode echocardiography were calculated.. Overweight and obese hypertensives had significantly (p < 0.05) higher BMI, waist-hip ratio (WHR), UAE and TGFbeta1 than lean hypertensives. Obese hypertensives had significantly (p < 0.05) higher total and indexed LVM values than lean hypertensives. Obese hypertensives had significantly (p < 0.05) higher BMI, UAE and TGFbeta1 than overweight hypertensives. In all subjects, TGFbeta1 correlated directly with BMI (r = 0.52; p < 0.0001), WHR (r = 0.48; p < 0.003), MBP (r = 0.31; p < 0.02) and UAE (r = 0.57; p < 0.0001). Multiple regression analysis indicated that BMI, MBP and UAE were able to explain the 47.9% TGFbeta1 variability (r = 0.69; p < 0.0001), and that TGFbeta1 was the best predictor of UAE changes (r = 0.60; p < 0.0001).. Our data suggest that TGFbeta1 levels are positively associated with BMI, MBP and UAE in hypertensive subjects. This also indicates that TGFbeta1 overproduction might be considered a pathophysiology mechanism of progressive renal function impairment in obese hypertensives.

Topics: Adult; Aged; Albuminuria; Body Mass Index; Body Weight; Electrocardiography; Female; Heart Function Tests; Humans; Hypertension, Renal; Kidney Diseases; Male; Middle Aged; Obesity; Regression Analysis; Transforming Growth Factor beta; Transforming Growth Factor beta1

Obesity is associated with hyperleptinemia and is also a risk factor for fibrosis and severity of fibrosis in several chronic liver diseases. The correlation between increased leptin, obesity and hepatic fibrosis prompted us to hypothesise that leptin has profibrogenic effects on the liver.. We analysed the role of leptin in liver fibrosis in leptin-deficient mice fed a diet which generates steatohepatitis, and in chronic carbon tetrachloride-induced hepatic injury.. Leptin-deficient mice failed to develop fibrosis during steatohepatitis or in response to chronic toxic liver injury, and failed to up-regulate collagen-I while developing similar hepatic injury as their genetic controls. Restitution of physiological levels of circulating leptin by injection of exogenous leptin, but not correction of the obese phenotype by dietary manipulation, restored liver fibrosis in leptin-deficient mice during chronic liver injury. These results confirmed the absolute requirement of leptin for hepatic fibrosis. We showed that leptin deficiency did not alter hepatic TNF regulation but that leptin is necessary for induction of bioactive transforming growth factor beta 1 (TGFbeta1) protein in the context of chronic liver injury.. These data establish that leptin is an essential mediator of hepatic fibrosis in response to chronic liver injury, whether metabolic or toxic in aetiology.

Topics: Animals; Carbon Tetrachloride; Chronic Disease; Disease Progression; Fatty Liver; Female; Leptin; Liver Cirrhosis; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Oxidative Stress; Phenotype; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Transforming growth factor-beta1 (TGF-beta1) has been demonstrated to be overexpressed in hypertension. Leptin, an adipocyte product, has been shown to play a role in obesity-related hypertension and in vitro studies demonstrated a biologic interaction between leptin and TGF-beta1. Thus, we evaluate a possible in vivo association between TGF-beta1, body mass index (BMI), and leptin circulating levels in hypertensive subjects.. Blood samples for fasting leptin and TGF-beta1, were evaluated in 29 overweight, 46 obese, and 29 nonobese hypertensive patients before and after a 12-week calorie-restricted diet. Monocyte cultures were used for in vitro experiments.. Transforming growth factor-beta1 was significantly elevated in hypertensive obese patients (n = 46) as compared with TGF-beta1 levels of hypertensive patients with normal BMI (n = 29) (8. 9 +/- 3 ng/mL v 4.4 +/- 2; P < .001). The circulating levels of TGF-beta1 were associated with BMI and leptin levels in an univariate analysis (r = 0.59, P < .0001; r = 0.62, P < .0001, respectively) and these associations were still present after stepwise multivariate analysis. Weight loss of 10% produced a parallel decrease in TGF-beta1 (from 8.9 +/- 3 ng/mL to 5.3 +/- 2.8 ng/mL; P < .01) and leptin levels (from 30 +/- 24 ng/mL to 17 +/- 14; P < .05). In vitro experiments showed that leptin is able to induce a dose-dependent increase in TGF-beta1 production and mRNA expression in human monocyte cultures.. Our data indicate that TGF-beta1 levels are positively associated with BMI and leptin levels in hypertensive patients and suggest that adipose tissue may be an important determinant of TGF-beta1 levels possibly by a leptin-dependent pathway.

Topics: Adult; Blood Pressure; Body Mass Index; Female; Gene Expression; Humans; Hypertension; In Vitro Techniques; Leptin; Male; Middle Aged; Obesity; Regression Analysis; RNA, Messenger; Transforming Growth Factor beta; Weight Loss

Recently established Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of naturally occurring obesity diabetes, exhibit progressive accumulation of connective tissue in the pancreas. The present study was designed to determine the pathogenic role of transforming growth factor-beta1 (TGF-beta1) in the development of pancreatic fibrosis in OLETF rats by investigating the serial changes in the expression of TGF-beta1 and extracellular matrix (ECM) in the pancreas. Progressive proliferation of connective tissue arose from the interstitial region surrounding islets at 20 wk of age and extended to the exocrine pancreas adjacent to the islets. TGF-beta1 mRNA levels in the pancreas increased at 20 wk of age and reached a peak value at 30 wk of age. Fibronectin (FN) and procollagen types I and III mRNAs peaked at 20 wk of age and remained at higher levels than those in the nondiabetic counterparts Long-Evans Tokushima Otsuka rats until 50 wk of age. Immunoreactivities for TGF-beta1 and FN were found in islets of OLETF rats at 20 wk of age and were seen in acinar and interstitial cells at 50 wk of age. Moreover, alpha-smooth muscle actin was located at interstitial region surrounding the islets. Proliferation of the connective tissue in the pancreas of OLETF rats closely correlated with expression of TGF-beta1 and ECM. Our results suggest that the development of pancreatic fibrosis in OLETF rats extends from endocrine to exocrine pancreas and that TGF-beta1 is involved in pancreatic fibrosis of OLETF rats.

Topics: Actins; Aging; Animals; Blotting, Northern; Collagen Type I; Collagen Type III; Connective Tissue; Diabetes Complications; Diabetes Mellitus; Extracellular Matrix; Fibronectins; Fibrosis; Immunohistochemistry; Islets of Langerhans; Male; Obesity; Pancreas; Rats; Rats, Inbred OLETF; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

Myostatin is a TGF-beta family member that acts as a negative regulator of muscle growth. Mice lacking the myostatin gene (Mstn) have a widespread increase in skeletal muscle mass resulting from a combination of muscle fiber hypertrophy and hyperplasia. Here we show that Mstn-null mice have a significant reduction in fat accumulation with increasing age compared with wild-type littermates, even in the setting of normal food intake (relative to body weight), normal body temperature, and a slightly decreased resting metabolic rate. To investigate whether myostatin might be an effective target for suppressing the development of obesity in settings of abnormal fat accumulation, we analyzed the effect of the Mstn mutation in two genetic models of obesity, agouti lethal yellow (A(y)) and obese (Lep(ob/ob)). In each case, loss of Mstn led to a partial suppression of fat accumulation and of abnormal glucose metabolism. Our findings raise the possibility that pharmacological agents that block myostatin function may be useful not only for enhancing muscle growth, but also for slowing or preventing the development of obesity and type 2 diabetes.

Topics: Adipose Tissue; Animals; Diabetes Mellitus, Type 2; Eating; Female; Glucose; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; Myostatin; Obesity; Organ Size; Transforming Growth Factor beta

We examined the role of inflammation in the development of renal interstitial fibrosis in Zucker obese rats, which rapidly present kidney lesions in the absence of hypertension and hyperglycemia. Type I and III collagens were quantified using a polarized light and computer-assisted image analyzer. The expression of mRNA encoding matrix components, adhesion molecules, chemokines, and growth factors was followed by RT-PCR. The presence of synthesized proteins as well as lymphocytes and macrophages was determined by immunohistochemistry. Interstitial fibrosis developed in two phases. The first phase occurred as early as 3 mo and resulted from a neosynthesis of type III collagen and fibronectin and a reduction of extracellular matrix catabolism, in parallel with an overexpression of transforming growth factor-beta(1) and in the absence of any lymphocyte or macrophage infiltration. After 6 mo, interstitial fibrosis worsened with a large accumulation of type I collagen, concomitantly with a large macrophage infiltration. Thus inflammation cannot explain the onset of interstitial fibrosis that developed in young, insulinoresistant, normoglycemic, obese Zucker rats but aggravated this process afterward.

Topics: Animals; Blood Glucose; Collagen; Creatinine; Fibronectins; Fibrosis; Gene Expression; Glomerulosclerosis, Focal Segmental; Hyperinsulinism; Hyperlipidemias; Image Processing, Computer-Assisted; Immunohistochemistry; Lymphocytes; Macrophages; Male; Obesity; Rats; Rats, Zucker; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta; Transforming Growth Factor beta1

The purpose of this study was to examine the histologic and functional changes that occur in the kidney in the early stages of obesity caused by a high-fat diet. Lean dogs (n = 8) were fed a standard kennel ration, and obese dogs (n = 8) were fed the standard kennel ration plus a supplement of cooked beef fat each day for 7 to 9 wk or 24 wk. Body weights were 58 +/- 5% greater and kidney weights were 31 +/- 7% greater in obese dogs, compared with the average values for lean dogs. Plasma renin activity and insulin concentrations were both 2.3-fold greater in obese dogs, compared with lean dogs. Obesity was associated with a mean arterial pressure increase of 12 +/- 3 mmHg, a 38 +/- 6% greater GFR, and a 61 +/- 7% higher renal plasma flow, compared with lean dogs. The glomerular Bowman's space area was significantly greater (+41 +/- 7%) in dogs fed the high-fat diet, compared with lean animals, mainly because of expansion of Bowman's capsule (+22 +/- 7%). There was also increased mesangial matrix and thickening of the glomerular and tubular basement membranes and the number of dividing cells (proliferating cell nuclear antigen-stained) per glomerulus was 36 +/- 8% greater in obese dogs, compared with lean dogs. There was also a trend for glomerular transforming growth factor-beta1 expression, as estimated by semiquantitative immunohistochemical analysis, to be elevated with the high-fat diet. Therefore, a high-fat diet caused increased arterial pressure, hyperinsulinemia, activation of the renin-angiotensin system, glomerular hyperfiltration, and structural changes in the kidney that may be the precursors of more severe glomerular injury associated with prolonged obesity.

Topics: Analysis of Variance; Animals; Blood Pressure; Dietary Fats; Dogs; Hemodynamics; Immunoenzyme Techniques; Insulin; Kidney; Obesity; Radioimmunoassay; Renin; Sodium; Transforming Growth Factor beta

Studies of renal injury III: Lipid-induced nephropathy in type II diabetes.. Nephrotoxicity from elevated circulating lipids occurs in experimental and clinical situations. We tested the hypothesis that lipid-induced nephropathy causes advanced renal failure in rats with type II diabetes and dyslipidemia.. First generation (F1) hybrid rats derived from the spontaneous hypertensive heart failure rat (SHHF/Gmi-fa) and the LA/NIH-corpulent rat (LA/N-fa) were studied for 41 weeks while being on specific diets. Group 1 (14 rats) ingested 11.5% protein, 47.9% fat, and 40.6% carbohydrate. Group 2 (8 rats) ingested 26.9% protein, 16.7% animal fat, and 56.4% carbohydrate, and group 3 (20 rats) ingested 20.2% protein, 40.4% soy and coconut oil, and 39.4% carbohydrate.. Hyperglycemia was more severe in rat groups 1 and 2 than in group 3. In contrast, circulating cholesterol and hydroperoxide levels were highest in group 3, intermediate in group 2, and lowest in group 1. Group 3 had severe renal failure secondary to glomerulosclerosis and tubulointerstitial disease, with striking deposition of the lipid peroxidation stress biomarker 4-hydroxynonenal in glomeruli and renal microvessels. Moreover, in group 3, increased arterial wall thickness also connoted vascular injury. In contrast, the glycoxidation stress biomarkers pentosidine and carboxymethyl-lysine were preferentially localized to renal tubules of hyperglycemic rats in groups 1 and 2 and did not segregate with the most severe renal injury. Glomerular and interstitial fibrosis was accompanied by proportional increases in renal transforming growth factor-beta1 levels, which were threefold higher in the hypercholesterolemic rats of group 3 than in the hyperglycemic rats of group 1.. Acquisition of non-nodular glomerular sclerosis and tubulointerstitial disease is dependent on lipoxidation stress in rats with type II diabetes. On the other hand, in the absence of hypercholesterolemia, prolonged glycoxidation stress does not appear to be uniquely nephrotoxic.

Topics: Animals; Cholesterol, LDL; Diabetic Nephropathies; Enzyme-Linked Immunosorbent Assay; Female; Glycation End Products, Advanced; Hypercholesterolemia; Immunohistochemistry; Kidney Function Tests; Kidney Glomerulus; Kidney Tubules, Proximal; Lipid Peroxidation; Male; Obesity; Rats; Renin; Transforming Growth Factor beta

Human adipose tissue has been shown to produce plasminogen activator inhibitor type 1 (PAI-1). However, the importance of adipose tissue in the regulation of the PAI-1 plasma level is not known. The aim of this study was to investigate the relation between the production of PAI-1 by adipose tissue, plasma PAI-1 level, and variables related to the insulin resistance state. The link between the production of PAI-1 inducers such as tumor necrosis factor-alpha and transforming growth factor-beta and the production of PAI-1 by adipose tissue was also evaluated. Blood samples were obtained as soon as possible to the induction of anesthesia from 30 patients undergoing elective abdominoplasty. PAI-1 antigen levels measured in conditioned media after a 19-hour incubation period of adipose tissue explants were significantly correlated with plasma PAI-1 antigen levels (r=0.54, P=0.004) and with systemic lipid parameters such as triglycerides and high density lipoprotein cholesterol (r=0. 46, P=0.014; r=-0.50, P=0.01, respectively) but not with insulinemia and body mass index. PAI-1 production by adipose tissue was correlated with those of TNF-alpha (r=0.5, P=0.01) and TGF-beta (r=0. 53, P=0.007). These results emphasize the role of adipose tissue in determining plasma levels of PAI-1, with a local contribution of TNF-alpha and TGF-beta in PAI-1 production by adipose tissue.

Topics: Adipose Tissue; Adolescent; Adult; Aged; Body Mass Index; Cholesterol, HDL; Culture Media, Conditioned; Female; Gene Expression Regulation; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Omentum; Organ Culture Techniques; Organ Specificity; Plasminogen Activator Inhibitor 1; Skin; Transforming Growth Factor beta; Triglycerides; Tumor Necrosis Factor-alpha

Obesity is associated with a cluster of abnormalities, including hypertension, insulin resistance, hyperinsulinemia, and elevated levels of both plasminogen activator inhibitor 1 (PAI-1) and transforming growth factor beta (TGF-beta). Although these changes may increase the risk for accelerated atherosclerosis and fatal myocardial infarction, the underlying molecular mechanisms remain to be defined. Although tumor necrosis factor alpha (TNF-alpha) has been implicated in the insulin resistance associated with obesity, its role in other disorders of obesity is largely unknown. In this report, we show that in obese (ob/ob) mice, neutralization of TNF-alpha or deletion of both TNF receptors (TNFRs) results in significantly reduced levels of plasma PAI-1 antigen, plasma insulin, and adipose tissue PAI-1 and TGF-beta mRNAs. Studies in which exogenous TNF-alpha was infused into lean mice lacking individual TNFRs indicate that TNF-alpha signaling of PAI-1 in adipose tissue can be mediated by either the p55 or the p75 TNFR. However, TNF-alpha signaling of TGF-beta mRNA expression in adipose tissue is mediated exclusively via the p55 TNFR. Our results suggest that TNF-alpha is a common link between the insulin resistance and elevated PAI-1 and TGF-beta in obesity. The chronic elevation of TNF-alpha in obesity thus may directly promote the development of the complex cardiovascular risk profile associated with this condition.

Topics: Animals; Gene Expression Regulation; Insulin Resistance; Mice; Mice, Obese; Obesity; Plasminogen Activator Inhibitor 1; Receptors, Tumor Necrosis Factor; Risk Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Altered expression of proteins of the fibrinolytic and coagulation cascades in obesity may contribute to the cardiovascular risk associated with this condition. We previously reported that plasminogen activator inhibitor 1 (PAI-1) is dramatically up-regulated in the plasma and adipose tissues of genetically obese mice. This change may disturb normal hemostatic balance and create a severe hypofibrinolytic state. Here we show that tissue factor (TF) gene expression also is significantly elevated in the epididymal and subcutaneous fat pads from ob/ob mice compared with their lean counterparts, and that its level of expression in obese mice increases with age and the degree of obesity. Cell fractionation and in situ hybridization analysis of adipose tissues indicate that TF mRNA is increased in adipocytes and in unidentified stromal vascular cells. Transforming growth factor beta (TGF-beta) is known to be elevated in the adipose tissue of obese mice, and administration of TGF-beta increased TF mRNA expression in adipocytes in vivo and in vitro. These observations raise the possibility that TF and TGF-beta may contribute to the increased cardiovascular disease that accompanies obesity and related non-insulin-dependent diabetes mellitus, and that the adipocyte plays a key role in this process. The recent demonstration that TF also influences angiogenesis, cell adhesion, and signaling suggests that its exact role in adipose tissue physiology/pathology, may be complex.

Topics: Adipocytes; Adipose Tissue; Animals; Fibrinolysis; Gene Expression; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Obese; Obesity; Plasminogen Activator Inhibitor 1; RNA, Messenger; Thromboplastin; Thrombosis; Transforming Growth Factor beta

To evaluate Transforming Growth Factor beta1, (TGF-beta1) plasma concentrations and the possible relationship between this growth factor and various hormones in obese women.. Case-control study.. Outpatient's Service for the Prevention and Treatment of Obesity at the University Hospital.. Twenty-five women with mild to moderate obesity, and 15 non-obese healthy women were used as controls.. Evaluation of TGF-beta1, insulin, prolactin, sex-hormone binding globulin, androstenedione, free triiodothyronine, free tetraiodothyronine, thyroid-stimulating hormone, dehydroepiandrosterone-sulfate, testosterone, insulin-like growth factor 1, cortisol and adrenocorticotropic hormone plasma concentrations in obese women. Blood samples were taken from fasting subjects for the determination of the above parameters.. In obese women plasma TGF-beta1 concentrations were lower than in controls. The obese subjects also had lower GH, IGF-1 and SHBG plasma concentrations and increased insulinaemia. A positive correlation was found between TGF-beta1 and both IGF-1 (r = 0.52; P < 0.01) and DHEA-S (r = 0.43; P < 0.05), while a negative correlation was found between TGF-beta1 and SHBG (r = -0.49; P < 0.05).. The reduction in TGF-beta1, an antilipogenic factor, may play a role in the pathogenesis of obesity and could be involved in the development of some obesity-related endocrine alterations.

Topics: Adult; Analysis of Variance; Case-Control Studies; Dehydroepiandrosterone Sulfate; Female; Growth Hormone; Humans; Insulin; Insulin-Like Growth Factor I; Linear Models; Obesity; Prolactin; Sex Hormone-Binding Globulin; Transforming Growth Factor beta

Tumor necrosis factor-alpha (TNF-alpha) is chronically elevated in the adipose tissue from obese humans and mice. This increase in TNF-alpha contributes to the insulin resistance, elevated plasminogen activator inhibitor-1 (PAI-1) levels, and cardiovascular complications associated with obesity and noninsulin-dependent diabetes (NIDDM). PAI-1 gene expression in adipose tissue is also stimulated by transforming growth factor-beta (TGF-beta). Experiments were performed to determine whether TGF-beta is regulated by TNF-alpha and elevated in obesity.. The concentration of TGF-beta and PAI-1 mRNA in murine adipose tissue and cultured 3T3-L1 adipocytes was determined by quantitative reverse transcription polymerase chain reaction (RT-PCR), and the cellular localization of these molecules was evaluated using in situ hybridization and cell fractionation. Total TGF-beta protein was determined by employing an ELISA assay.. TGF-beta mRNA and protein were increased in the adipose tissue from two different strains of genetically obese mice (i.e., ob/ob and db/db), compared with their lean counterparts. This increase in TGF-beta may result from TNF-alpha since TNF-alpha increased TGF-beta mRNA expression in the adipose tissue of lean mice and stimulated TGF-beta production by cultured adipocytes. Administration of TGF-beta increased PAI-1 antigen in the plasma and PAI-1 mRNA in the adipocytes of lean mice, and enhanced the rate of PAI-1 synthesis by adipocytes in vitro.. TNF-alpha contributes to the elevated TGF-beta expression demonstrated in the adipose tissue of obese mice. A potential role for TGF-beta in the increased PAI-1 and vascular pathologies associated with obesity/NIDDM is suggested.

Topics: 3T3 Cells; Adipose Tissue; Animals; Cell Fractionation; Gene Expression Regulation; Insulin; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Plasminogen Activator Inhibitor 1; RNA, Messenger; Transforming Growth Factor alpha; Transforming Growth Factor beta

Interleukin-1beta (IL-1beta) induces anorexia, fever, sleep changes, and neuroendocrine alterations when administered into the brain. Here, we investigated the regulation of the IL-1beta system (ligand, receptors, receptor accessory protein, and receptor antagonist), tumor necrosis factor-alpoha (TNF-alpha), transforming growth factor (TGF)-beta1, and TGF-alpha mRNAs in the hypothalamus of obese (fa/fa) and lean (Fa/Fa) Zucker rats in response to the intracerebroventricular microinfusion of IL-1beta (8.0 ng/24 hr for 72 hr, a dose that yields estimated pathophysiological concentrations in the cerebrospinal fluid). IL-1beta increased IL-1beta, IL-1 receptor types I and II (IL-1RI and IL-1RII), IL-1 receptor accessory protein soluble form (IL-1R AcP II), IL-1 receptor antagonist (IL-1Ra), TNF-alpha, and TGF-beta1 mRNAs in the hypothalamus from obese and lean rats. IL-1beta-induced IL-1beta system and ligand (IL-1beta, TNF-alpha, and TGF-beta1) mRNA profiles were highly intercorrelated in the same samples. Levels of membrane-bound IL-1R AcP and TGF-alpha mRNAs did not change. Heat-inactivated IL-1beta had no effect. The data suggest 1) the operation of an IL-1beta feedback system (IL-1beta/IL-1RI/IL-1R Acp II/IL-1RII/IL-1Ra) and 2) potential cytokine-cytokine interactions with positive (IL-1beta <--> TNF-alpha) and negative (TGF-beta1 --> IL-1beta/TNF-alpha) feedback. Dysregulation of the IL-1beta feedback system and the TGF-beta1/IL-1beta-TNF-alpha balance may have implications for neurological disorders associated with high levels of IL-1beta in the brain.

Topics: Animals; Feedback; Hypothalamus; Interleukin-1; Male; Obesity; Rats; Rats, Zucker; RNA, Messenger; Transforming Growth Factor alpha; Transforming Growth Factor beta

Obesity is known to predispose to attenuated fibrinolysis attributable to increased concentrations in plasma of type-1 plasminogen activator inhibitor (PAI-1), the primary physiological inhibitor of endogenous fibrinolysis. PAI-1 is present in neointimal vascular smooth muscle cells and lipid-laden macrophages.. The present study was designed to determine whether PAI-1 expression occurs in adipose tissue as well, thereby potentially contributing to increased cardiovascular risk associated with obesity. 3T3-L1 preadipocytes were differentiated into adipocytes by exposing them to isobutylxanthine (0.5 mmol/L) and dexamethasone (0.25 mumol/L) over 7 days and incubated for 24 hours with transforming growth factor-beta (TGF-beta), known to augment PAI-1 synthesis in several cell types and to be released from platelets when they are activated. TGF-beta increased PAI-1 activity in the conditioned media of the 3T3-L1-derived cells in a concentration-dependent fashion without significantly affecting cell proliferation. Western blotting and immunoprecipitation of 35S-labeled PAI-1 showed that the increased PAI-1 activity paralleled increased PAI-1 protein. Northern blotting showed that increased PAI-1 mRNA preceded increased accumulation of PAI-1 activity and protein in the conditioned media. Furthermore, TGF-beta (10 ng/g body wt) administered in vivo increased PAI-1 activity in mouse plasma and PAI-1 mRNA expression in mouse adipose tissue.. Increased plasma PAI-1 activity in obese human subjects may result from PAI-1 release from an increased mass of adipose tissue, particularly in association with thrombosis and elaboration of TGF-beta from platelet alpha-granules into the circulation. The increased PAI-1 may exacerbate vascular disease by shifting the balance between thrombosis and thrombolysis toward thrombosis and consequently exposing luminal surfaces of vessels to mitogens associated with microthrombi over protracted intervals.

Topics: Adipocytes; Animals; Cardiovascular Diseases; Cell Differentiation; Cell Division; Cell Line; Dose-Response Relationship, Drug; Mice; Obesity; Plasminogen Activator Inhibitor 1; Risk Factors; RNA, Messenger; Transforming Growth Factor beta