cyclin-d1 and Obesity

Obesity has become a health threat and hard enough to deal with. Evidences show that metformin could inhibit adipogenesis and combat obesity, while its mechanisms remain to be elucidated more comprehensively. In this study, we found that administration of metformin could combat obesity of mice induced by high-fat diet (HFD), indicated by strikingly decreased body weight and weight of inguinal white adipose tissue (iWAT) and epidydimal white adipose tissue (eWAT) compared with the control group. Mechanically, we revealed that metformin could inhibit protein expression of FTO, leading to increased m

Topics: 3T3-L1 Cells; Adipocytes; Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Animals; Cyclin D1; Cyclin-Dependent Kinase 2; Metformin; Mice; Obesity; RNA-Binding Proteins; Transcription Factors

Obesity with dysfunctional adipose cells is the major cause of the current epidemic of type 2 diabetes (T2D). We examined senescence in human adipose tissue cells from age- and BMI-matched individuals who were lean, obese, and obese with T2D. In obese individuals and, more pronounced, those with T2D, we found mature and fully differentiated adipose cells to exhibit increased senescence similar to what we previously have shown in the progenitor cells. The degree of adipose cell senescence was positively correlated with whole-body insulin resistance and adipose cell size. Adipose cell protein analysis revealed dysfunctional cells in T2D with increased senescence markers reduced PPAR-γ, GLUT4, and pS473AKT. Consistent with a recent study, we found the cell cycle regulator cyclin D1 to be increased in obese cells and further elevated in T2D cells, closely correlating with senescence markers, ambient donor glucose, and, more inconsistently, plasma insulin levels. Furthermore, fully differentiated adipose cells were susceptible to experimentally induced senescence and to conditioned medium increasing cyclin D1 and responsive to senolytic agents. Thus, fully mature human adipose cells from obese individuals, particularly those with T2D become senescent, and SASP secretion by senescent progenitor cells can play an important role in addition to donor hyperinsulinemia.

Topics: Adipose Tissue; Biomarkers; Culture Media, Conditioned; Cyclin D1; Diabetes Mellitus, Type 2; Glucose; Humans; Insulin Resistance; Insulins; Obesity; Peroxisome Proliferator-Activated Receptors

The purpose of this study was to establish a rat asthma model and extract MUC5AC to explore the mechanism of mucin 5AC (MUC5AC) signaling pathway regulating the function of asthmatic airway smooth muscle cells (ASMC) and participating in asthmatic airway remodeling. Western blot was used to detect β-catenin (β-catenin), glycogen synthase kinase-3β (GSK-3β), proto-oncogene MUC5AC and cyclin D1 (cyclin D1) in MUC5AC of asthmatic and normal groups. After inhibiting the interaction between β-catenin and transcription cofactor p300 / CBP in ASMC of the asthma group and control group, the cell viability and cycle changes of ASMC were detected by the CCK-8 method and flow cytometry. After inhibiting the activity of P38 mitogen-activated protein kinase (MAPK), the protein expression changes of c-Myc and cyclin D1 were detected by Western blot. Results showed that comprehensive HE staining results of lung tissue sections indicate that the experimental rat model of asthma airway remodeling was successfully established. Compared with the control group, 100 fxmol and L1 Efaroxan promoted insulin secretion (P <0.01), and administration of the MUC5AC antagonist KU14R significantly inhibited the effect of MUC5AC.Western blot showed that the protein expression levels of β-catenin, c-Myc and cyclin D1 in ASMC of the obese asthma group were significantly higher than those of the control group (P <0.05), while the protein expression level of GSK-3β was lower than Control group (P <0.05). After inhibiting the interaction between β-catenin and p300 / CBP, the decrease in cell viability and the degree of cell cycle change of ASMC in the asthma group were more obvious than those in the control group (P <0.05). After inhibiting the activity of P38 MAPK, the expressions of the target proteins c-Myc and cyclin D1 in the MUC5AC signaling pathway in ASMC model rats and control rats were down-regulated, and the difference was statistically significant (P <0.05). The conclusion was that the Wnt/β-catenin signaling pathway can regulate the proliferation and differentiation of ASMC by up-regulating the expression level of cMyc. Cyclin D1 interacts with the MAPK signaling pathway, thereby affecting the function of ASMC and participating in asthma airway remodeling.

Topics: Airway Remodeling; Animals; Asthma; beta Catenin; Cell Proliferation; Cyclin D1; Glycogen Synthase Kinase 3 beta; Mucin 5AC; Obesity; p38 Mitogen-Activated Protein Kinases; Rats; Wnt Signaling Pathway

Obesity is considered an important factor for many chronic diseases, including diabetes, cardiovascular disease and cancer. The expansion of adipose tissue in obesity is due to an increase in both adipocyte progenitor differentiation and mature adipocyte cell size. Adipocytes, however, are thought to be unable to divide or enter the cell cycle. We demonstrate that mature human adipocytes unexpectedly display a gene and protein signature indicative of an active cell cycle program. Adipocyte cell cycle progression associates with obesity and hyperinsulinemia, with a concomitant increase in cell size, nuclear size and nuclear DNA content. Chronic hyperinsulinemia in vitro or in humans, however, is associated with subsequent cell cycle exit, leading to a premature senescent transcriptomic and secretory profile in adipocytes. Premature senescence is rapidly becoming recognized as an important mediator of stress-induced tissue dysfunction. By demonstrating that adipocytes can activate a cell cycle program, we define a mechanism whereby mature human adipocytes senesce. We further show that by targeting the adipocyte cell cycle program using metformin, it is possible to influence adipocyte senescence and obesity-associated adipose tissue inflammation.

Topics: Adipocytes; Adipose Tissue; Cell Cycle; Cell Differentiation; Cellular Senescence; Cyclin D1; Humans; Hyperinsulinism; Hypoglycemic Agents; Metformin; Obesity

Unveiling the key pathways underlying postnatal beta-cell proliferation can be instrumental to decipher the mechanisms of beta-cell mass plasticity to increased physiological demand of insulin during weight gain and pregnancy. Using transcriptome and global Serine Threonine Kinase activity (STK) analyses of islets from newborn (10 days old) and adult rats, we found that highly proliferative neonatal rat islet cells display a substantially elevated activity of the mitogen activated protein 3 kinase 12, also called dual leucine zipper-bearing kinase (Dlk). As a key upstream component of the c-Jun amino terminal kinase (Jnk) pathway, Dlk overexpression was associated with increased Jnk3 activity and was mainly localized in the beta-cell cytoplasm. We provide the evidence that Dlk associates with and activates Jnk3, and that this cascade stimulates the expression of Ccnd1 and Ccnd2, two essential cyclins controlling postnatal beta-cell replication. Silencing of Dlk or of Jnk3 in neonatal islet cells dramatically hampered primary beta-cell replication and the expression of the two cyclins. Moreover, the expression of Dlk, Jnk3, Ccnd1 and Ccnd2 was induced in high replicative islet beta cells from ob/ob mice during weight gain, and from pregnant female rats. In human islets from non-diabetic obese individuals, DLK expression was also cytoplasmic and the rise of the mRNA level was associated with an increase of JNK3, CCND1 and CCND2 mRNA levels, when compared to islets from lean and obese patients with diabetes. In conclusion, we find that activation of Jnk3 signalling by Dlk could be a key mechanism for adapting islet beta-cell mass during postnatal development and weight gain.

Topics: Animals; Cell Proliferation; Cyclin D1; Cyclin D2; Female; Glucose; Humans; Insulin; Insulin-Secreting Cells; MAP Kinase Kinase Kinases; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 10; Obesity; Pancreas; Rats; Rats, Sprague-Dawley; RNA Interference; RNA, Small Interfering; Signal Transduction

Our previous study found that platelet counts were positively associated with body fat percentage in human. In the present study, we conducted a reverse translational study to explore the role of platelets in modulating pre-adipocyte proliferation in mice.. Mouse pre-adipocyte cell line (3T3-L1) and human pre-adipocytes harvested from female subcutaneous fat were used. Pre-adipocytes were co-cultured with platelets or platelet releasate, which were isolated from mice or humans. The cell viability and proliferative ability of the pre-adipocytes were examined by MTT and flow cytometry assays. Western blotting analysis was used to determine the phosphorylation levels of proteins in the mTOR pathway.. The number of platelets in the adipose tissues from obese mice was significantly higher than that from lean mice. Platelets and collagen-activated platelet releasate stimulated the proliferation of human pre-adipocytes and 3T3-L1 cells in vitro. Besides, platelets from obese mice were more potent in stimulating pre-adipocyte proliferation than those from lean control mice. Mechanistically, platelets enhanced pre-adipocyte proliferation through the acceleration of cell cycle progression from G0/G1 to S phase cell cycle progression. At the molecular level, platelets promoted pre-adipocyte proliferation through mTOR pathway-mediated upregulation of cyclin D1 expression.. In conclusion, platelets and platelet releasate play an important role in the proliferation of pre-adipocytes. Our study may provide new clues and the molecular mechanism of the causal pathways between platelets and body fat to explain the finding we observed in population study.

Topics: 3T3-L1 Cells; Adipocytes; Adipose Tissue; Animals; Apoptosis; Blood Platelets; Cell Communication; Cell Proliferation; Cell Survival; Cells, Cultured; Cyclin D1; Female; Humans; Male; Mice; Mice, Inbred C57BL; Obesity; Platelet Count; Specific Pathogen-Free Organisms; Subcutaneous Fat; TOR Serine-Threonine Kinases; Translational Research, Biomedical

To assess cyclin D1 and PTEN immunoexpression in benign endometrial polyps (EPs) in asymptomatic postmenopausal women and its correlation with obesity.

Topics: Cross-Sectional Studies; Cyclin D1; Female; Humans; Middle Aged; Obesity; Polyps; Postmenopause; PTEN Phosphohydrolase; Uterine Diseases

Type 2 diabetes, which is mainly linked to obesity, is associated with increased incidence of liver cancer. We have previously found that in various models of obesity/diabetes, hyperinsulinemia maintains heightened hepatic expression of cyclin D1, suggesting a plausible mechanism linking diabetes and liver cancer progression. Here we show that cyclin D1 is greatly elevated in human livers with diabetes and is among the most significantly upregulated genes in obese/diabetic liver tumors. Liver-specific cyclin D1 deficiency protected obese/diabetic mice against hepatic tumorigenesis, whereas lean/nondiabetic mice developed tumors irrespective of cyclin D1 status. Cyclin D1 dependency positively correlated with liver cancer sensitivity to palbociclib, an FDA-approved CDK4 inhibitor, which was effective in treating orthotopic liver tumors under obese/diabetic conditions. The antidiabetic drug metformin suppressed insulin-induced hepatic cyclin D1 expression and protected against obese/diabetic hepatocarcinogenesis. These results indicate that the cyclin D1-CDK4 complex represents a potential selective therapeutic vulnerability for liver tumors in obese/diabetic patients. SIGNIFICANCE: Obesity/diabetes-associated liver tumors are specifically vulnerable to cyclin D1 deficiency and CDK4 inhibition, suggesting that the obese/diabetic environment confers cancer-selective dependencies that can be therapeutically exploited.

Topics: Animals; Antineoplastic Agents; Cyclin D1; Cyclin-Dependent Kinase 4; Diabetes Mellitus, Type 2; Hyperinsulinism; Hypoglycemic Agents; Liver Neoplasms, Experimental; Male; Metformin; Mice; Obesity; Piperazines; Protein Kinase Inhibitors; Pyridines; Up-Regulation

Epidemiological studies have convincingly suggested that obesity is an important risk factor for postmenopausal breast cancer, but the mechanisms responsible for this relationship are still not fully understood. We hypothesize that obesity creates a low-grade inflammatory microenvironment, which stimulates Wnt-signaling and thereby promotes the development of breast cancer. To test this hypothesis, we evaluated the correlations between expression of multiple inflammatory cytokines and Wnt pathway downstream genes in mammary tissues from women (age ≥ 50) undergoing reduction mammoplasty. Moreover, we specifically examined the role of tumor necrosis factor-α (TNF-α), an important proinflammatory cytokine associated with obesity and a possible modulator of the Wnt pathway. The regulatory effects of TNF-α on Wnt pathway targets were measured in an ex vivo culture of breast tissue treated with anti-TNF-α antibody or TNF-α recombinant protein. We found that BMI was positively associated with the secretion of inflammatory cytokines IL-1β, IL-6 and TNF-α, all of which were negatively correlated with the expression of SFRP1. The transcriptional expression of Wnt-signaling targets, AXIN2 and CYCLIN D1, were higher in mammary tissue from women with BMI ≥ 30 compared to those with BMI < 30. Our ex vivo work confirmed that TNF-α is causally linked to the up-regulation of active β-CATENIN, a key component in the Wnt pathway, and several Wnt-signaling target genes (i.e. CYCLIN D1, AXIN2, P53 and COX-2). Collectively, these findings indicate that obesity-driven inflammation elevates Wnt-signaling in mammary tissue and thereby creates a microenvironment conducive to the development of breast cancer.

Topics: Antibodies, Blocking; Axin Protein; beta Catenin; Breast Neoplasms; Cell Proliferation; Cells, Cultured; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Inflammation; Intercellular Signaling Peptides and Proteins; Interleukin-1beta; Interleukin-6; Mammary Glands, Human; Membrane Proteins; Middle Aged; Obesity; Tumor Microenvironment; Tumor Necrosis Factor-alpha; Wnt Signaling Pathway

Indole-3-carbinol (I3C), a derivative abundant in cruciferous vegetables such as cabbage, is well known for its various health benefits such as chemo-preventive and anti-obesity effects. I3C is easily metabolized to 3,3'-diindolylmethane (DIM), a more stable form, in acidic conditions of the stomach. However, the anti-obesity effect of DIM has not been investigated clearly. We sought to investigate the effect of DIM on diet-induced obesity and to elucidate its underlying mechanisms.. High-fat diet (HFD)-fed obese mouse and MDI-induced 3T3-L1 adipogenesis models were used to study the effect of DIM. We observed that the administration of DIM (50 mg/kg BW) significantly suppressed HFD-induced obesity, associated with a decrease in adipose tissue. Additionally, we observed that DIM treatment (40 and 60 μM), but not I3C treatment, significantly inhibited MDI-induced adipogenesis by reducing the levels of several adipogenic proteins such as PPAR-γ and C/EBPα. DIM, but not I3C, suppressed cell cycle progression in the G1 phase, which occurred in the early stage of adipogenesis, inducing post-translational degradation of cyclin D1 by inhibiting ubiquitin specific peptidase 2 (USP2) activities.. Our findings indicate that cruciferous vegetables, which can produce DIM as a metabolite, have the potential to prevent or treat chronic obesity.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Animals; CCAAT-Enhancer-Binding Proteins; Cell Differentiation; Cyclin D1; Diet, High-Fat; Indoles; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; PPAR gamma; Ubiquitin Thiolesterase; Ubiquitin-Specific Proteases

Childhood obesity is associated with renal diseases. Maternal obesity is a risk factor linked to increased adipocytokines and metabolic disorders in the offspring. Therefore, we studied the impact of maternal obesity on renal-intrinsic insulin and adipocytokine signaling and on renal function and structure. To induce maternal obesity, female mice were fed a high-fat diet (HFD) or a standard diet (SD; control group) prior to mating, during gestation, and throughout lactation. A third group of dams was fed HFD only during lactation (HFD-Lac). After weaning at postnatal day (P)21, offspring of all groups received SD. Clinically, HFD offspring were overweight and insulin resistant at P21. Although no metabolic changes were detected at P70, renal sodium excretion was reduced by 40%, and renal matrix deposition increased in the HFD group. Mechanistically, two stages were differentiated. In the early stage (P21), compared with the control group, HFD showed threefold increased white adipose tissue, impaired glucose tolerance, hyperleptinemia, and hyperinsulinemia. Renal leptin/Stat3-signaling was activated. In contrast, the Akt/ AMPKα cascade and Krüppel-like factor 15 expression were decreased. In the late stage (P70), although no metabolic differences were detected in HFD when compared with the control group, leptin/Stat3-signaling was reduced, and Akt/AMPKα was activated in the kidneys. This effect was linked to an increase of proliferative (cyclinD1/D2) and profibrotic (ctgf/collagen IIIα1) markers, similar to leptin-deficient mice. HFD-Lac mice exhibited metabolic changes at P21 similar to HFD, but no other persistent changes. This study shows a link between maternal obesity and metabolic programming of renal structure and function and intrinsic-renal Stat3/Akt/AMPKα signaling in the offspring.

Topics: Adipokines; Adipose Tissue, White; AMP-Activated Protein Kinases; Animals; Collagen Type III; Connective Tissue Growth Factor; Cyclin D1; Cyclin D2; Diet, High-Fat; DNA-Binding Proteins; Female; Glucose Intolerance; Insulin; Insulin Resistance; Kidney; Kruppel-Like Transcription Factors; Leptin; Male; Mice; Obesity; Overweight; Pregnancy; Pregnancy Complications; Prenatal Exposure Delayed Effects; Proto-Oncogene Proteins c-akt; Signal Transduction; Sodium; STAT3 Transcription Factor; Transcription Factors

The stemness maintenance of adipose-derived stem cells (ADSCs) is important for adipose homeostasis and energy balance. Programmed cell death 4 (Pdcd4) has been demonstrated to be involved in the development of obesity, but its possible roles in ADSC function and adipogenic capacity remain unclear. In this study, we demonstrate that Pdcd4 is a key controller that limits the self-renewal and white-to-beige transdifferentiation of ADSCs. Pdcd4 deficiency in mice caused stemness enhancement of ADSCs as evidenced by increased expression of CD105, CD90, Nanog and Oct4 on ADSCs, together with enhanced in situ proliferation in adipose tissues. Pdcd4 deficiency promoted proliferation, colony formation of ADSCs and drove more ADSCs entering the S phase accompanied by AKT activation and cyclinD1 upregulation. Blockade of AKT signaling in Pdcd4-deficient ADSCs led to a marked decline in cyclinD1, S-phase entry and cell proliferation, revealing AKT as a target for repressing ADSC self-renewal by Pdcd4. Intriguingly, depletion of Pdcd4 promoted the transdifferentiation of ADSCs into beige adipocytes. A reduction in lipid contents and expression levels of white adipocyte markers including C/EBPα, PPAR-γ, adiponectin and αP2 was detected in Pdcd4-deficient ADSCs during white adipogenic differentiation, substituted by typical beige adipocyte characteristics including small, multilocular lipid droplets and UCP1 expression. More lactate produced by Pdcd4-deficient ADSCs might be an important contributor to the expression of UCP1 and white-to-beige transdifferentiation. In addition, an elevation of UCP1 expression was confirmed in white adipose tissues from Pdcd4-deficient mice upon high-fat diet, which displayed increased energy expenditure and resistance to obesity as compared with wild-type obese mice. These findings provide evidences that Pdcd4 produces unfavorable influences on ADSC stemness, which contribute to adipose dysfunction, obesity and metabolic syndromes, thereby proposing Pdcd4 as a potential intervening target for regulating ADSC function.

Topics: Adipogenesis; Adiponectin; Adipose Tissue; Adipose Tissue, Brown; Adipose Tissue, White; Animals; Apoptosis Regulatory Proteins; CCAAT-Enhancer-Binding Proteins; Cell Transdifferentiation; Cells, Cultured; Cyclin D1; Diet, High-Fat; Mice; Mice, Inbred C57BL; Mice, Knockout; Nanog Homeobox Protein; Obesity; Octamer Transcription Factor-3; PPAR gamma; RNA-Binding Proteins; SOXB1 Transcription Factors; Stem Cells; Uncoupling Protein 1

Obesity greatly influences risk, progression and prognosis of breast cancer. As molecular effects of obesity are largely mediated by adipocytokine leptin, finding effective novel strategies to antagonize neoplastic effects of leptin is desirable to disrupt obesity-cancer axis. Present study is designed to test the efficacy of honokiol (HNK), a bioactive polyphenol from Magnolia grandiflora, against oncogenic actions of leptin and systematically elucidate the underlying mechanisms. Our results show that HNK significantly inhibits leptin-induced breast-cancer cell-growth, invasion, migration and leptin-induced breast-tumor-xenograft growth. Using a phospho-kinase screening array, we discover that HNK inhibits phosphorylation and activation of key molecules of leptin-signaling-network. Specifically, HNK inhibits leptin-induced Wnt1-MTA1-β-catenin signaling in vitro and in vivo. Finally, an integral role of miR-34a in HNK-mediated inhibition of Wnt1-MTA1-β-catenin axis was discovered. HNK inhibits Stat3 phosphorylation, abrogates its recruitment to miR-34a promoter and this release of repressor-Stat3 results in miR-34a activation leading to Wnt1-MTA1-β-catenin inhibition. Accordingly, HNK treatment inhibited breast tumor growth in diet-induced-obese mouse model (exhibiting high leptin levels) in a manner associated with activation of miR-34a and inhibition of MTA1-β-catenin. These data provide first in vitro and in vivo evidence for the leptin-antagonist potential of HNK revealing a crosstalk between HNK and miR34a and Wnt1-MTA1-β-catenin axis.

Topics: Animals; Antineoplastic Agents, Phytogenic; beta Catenin; Biphenyl Compounds; Breast Neoplasms; Cell Movement; Cell Proliferation; Cell Transformation, Neoplastic; Cyclin D1; Drugs, Chinese Herbal; Female; Histone Deacetylases; Humans; Leptin; Lignans; Magnolia; MCF-7 Cells; Mice; Mice, Nude; Mice, Obese; MicroRNAs; Neoplasm Invasiveness; Obesity; Phosphorylation; Plant Extracts; Promoter Regions, Genetic; Repressor Proteins; RNA Interference; RNA, Small Interfering; Signal Transduction; Spheroids, Cellular; STAT3 Transcription Factor; Trans-Activators; Tumor Cells, Cultured; Wnt1 Protein; Xenograft Model Antitumor Assays

Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ) expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB): ≥30 kg/m2; normal weight (N): 18.5-24.9 kg/m2). Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231) and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu) following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s) mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

Topics: Animals; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Estrogen Receptor beta; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Mice; Obesity; Proto-Oncogene Proteins c-bcl-2; Receptor, ErbB-2; Signal Transduction; Transcription, Genetic

In the present study, we aimed to investigate the antiobesity effect of CAPE in vivo, and the mechanism by which CAPE regulates body weight in vitro. To confirm the antiobesity effect of CAPE in vivo, mice were fed with a high fat diet (HFD) with different concentrations of CAPE for 5 weeks. CAPE significantly reduced body weight gain and epididymal fat mass in obese mice fed a HFD. In accordance with in vivo results, Oil red O staining results showed that CAPE significantly suppressed MDI-induced adipogenesis of 3T3-L1 preadipocytes. FACS analysis results showed that CAPE delayed MDI-stimulated cell cycle progression, thereby contributing to inhibit mitotic clonal expansion (MCE), which is a prerequisite step for adipogenesis. Also, CAPE regulated the expression of cyclin D1 and the phosphorylation of ERK and Akt, which are upstream of cyclin D1. These results suggest that CAPE exerts an antiobesity effect in vivo, presumably through inhibiting adipogenesis at an early stage of adipogenesis.

Topics: Adipocytes; Adipogenesis; Animals; Anti-Obesity Agents; Caffeic Acids; Cyclin D1; Diet, High-Fat; Down-Regulation; Humans; Male; Mice; Mice, Inbred C57BL; Mitosis; Obesity; Phenylethyl Alcohol; Propolis

Recent epidemiological studies provide strong evidence suggesting obesity is a risk factor in several cancers, including thyroid cancer. However, the molecular mechanisms by which obesity increases the risk of thyroid cancer are poorly understood. In this study, we evaluated the effect of diet-induced obesity on thyroid carcinogenesis in a mouse model that spontaneously develops thyroid cancer (Thrb(PV/PV)Pten(+/-) mice). These mice harbor a mutated thyroid hormone receptor-β (denoted as PV) and haplodeficiency of the Pten gene. A high-fat diet (HFD) efficiently induced the obese phenotype in Thrb(PV/PV)Pten(+/-) mice after 15 weeks. Thyroid tumor growth was markedly greater and survival was significantly lower in Thrb(PV/PV)Pten(+/-) mice fed an HFD than in controls fed a low-fat diet (LFD). The HFD increased thyroid tumor cell proliferation by increasing the protein levels of cyclin D1 and phosphorylated retinoblastoma protein to propel cell cycle progression. Histopathological analysis showed that the frequency of anaplasia of thyroid cancer was significantly greater (2.6-fold) in the HFD group than the LFD group. The HFD treatment led to an increase in parametrial/epididymal fat pad and elevated serum leptin levels in Thrb(PV/PV)Pten(+/-) mice. Further molecular analyses indicated that the HFD induced more aggressive pathological changes that were mediated by increased activation of the Janus kinase 2-signaling transducer and activator of transcription 3 (STAT3) signaling pathway and induction of STAT3 target gene expression. Our findings demonstrate that diet-induced obesity exacerbates thyroid cancer progression in Thrb(PV/PV)Pten(+/-) mice and suggest that the STAT3 signaling pathway could be tested as a potential target for the treatment of thyroid cancer.

Topics: Animals; bcl-X Protein; Cell Cycle; Cell Proliferation; Cyclin D1; Diet, High-Fat; Disease Models, Animal; Female; Heterozygote; Janus Kinase 2; Leptin; Male; Mice; Mutation; Obesity; Phosphorylation; Proto-Oncogene Proteins c-myc; PTEN Phosphohydrolase; Retinoblastoma Protein; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; STAT3 Transcription Factor; Thyroid Gland; Thyroid Hormone Receptors beta; Thyroid Neoplasms

The molecular mechanisms underlying the association between obesity (BMI ≥ 30 kg/m(2)) and asthma are poorly understood. Since shifts in the fate of bronchial cells due to low-grade systemic inflammation may provide a possible explanation, we investigated whether two of the best documented functional variants in cell cycle control genes modify the obesity-asthma association.. We genotyped 5930 SAPALDIA cohort participants for the single-nucleotide polymorphisms (SNPs) rs9344 in the cyclin D1 gene (CCND1) and rs1042522 in the gene encoding tumor protein 53 (TP53). We assessed the independent association of these SNPs and obesity with asthma prevalence and incidence.. The CCND1 SNP modified the association between obesity and asthma prevalence (p(interaction )= 0.03). The odds ratios (ORs) and 95% confidence intervals (CIs) for reporting a physician diagnosis of asthma at baseline, comparing obese with non-obese participants, were 1.09 (0.51-2.33), 1.64 (0.94-2.88), and 3.51 (1.63-7.53) for GG, GA, and AA genotypes, respectively. We found comparable genotype differences for incident asthma within the 11 years of follow-up. As for the TP53 SNP, the interactions with obesity status with respect to asthma were not statistically significant.. Our results suggest that obesity may contribute to asthma and associated tissue remodeling by modifying the processes related to the CCND1 gene activity.

Topics: Adolescent; Adult; Asthma; Cohort Studies; Cyclin D1; DNA; DNA-Binding Proteins; Female; Genotype; Humans; Incidence; Male; Middle Aged; Obesity; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Prevalence; Regression Analysis; Switzerland; Young Adult

Obesity is known to be an important risk factor for many types of cancer, such as breast, prostate, liver and endometrial cancer. Recently, epidemiological studies have indicated that obesity correlates with an increased risk of developing ovarian cancer, the most lethal gynecological cancer in developed countries. Leptin is predominantly produced by adipocytes and acts as a growth factor and serum leptin levels positively correlate with the amount of body fat. In this study, we investigated the effects of leptin on the growth of ovarian cancer cells and the underlying mechanism(s) of action. Our results showed that leptin stimulated the growth of the OVCAR-3 ovarian cancer cell line using MTT assay and trypan blue exclusion. Using western blot analysis, we found that leptin enhanced the expression of cyclin D1 and Mcl-1, which are important regulators of cell proliferation and the inhibition of apoptosis. To investigate the signaling pathways that mediate the effects of leptin, cells were treated with leptin plus specific inhibitors of JAK2, PI3K/Akt and MEK/ERK1/2 and analysis of the phosphorylation state of proteins was carried out by western blot assays. We showed that the activation of the MEK/ERK1/2 and PI3K/Akt signaling pathways were involved in the growth-stimulating effect of leptin on ovarian cancer cell growth and the specific inhibitors of PI3K/Akt and MEK/ERK1/2 revealed that these two pathways interacted with each other. Our data demonstrate that leptin upregulates the expression of cyclin D1 and Mcl-1 to stimulate cell growth by activating the PI3K/Akt and MEK/ERK1/2 pathways in ovarian cancer.

Topics: Apoptosis; Butadienes; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Enzyme Activation; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Female; Flavonoids; Humans; Janus Kinase 2; Leptin; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Myeloid Cell Leukemia Sequence 1 Protein; Nitriles; Obesity; Ovarian Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Tyrphostins

The deadenylase nocturnin (Noc, Ccrn4l) has been recently found to regulate lipid metabolism and to control preadipocyte differentiation. Here, we showed that among the five deadenylases tested, Noc and Pan2 exhibited a biphasic expression which is out of phase to each other during adipocyte differentiation of 3T3-L1 cells. The expression levels of other deadenylases, including Parn, Ccr4, and Caf1, were relatively unchanged or reduced. The immediate early expressed Noc during 3T3-L1 adipogenesis was involved in regulating mitotic clonal expansion (MCE) and cyclin D1 expression, as demonstrated in Noc-silenced 3T3-L1 cells and Noc(-/-) primary mouse embryonic fibroblasts (MEFs). Transcriptional profiling of Noc-depleted 3T3-L1 adipocytes revealed that most of the differentially expressed genes were related to cell growth and proliferation. In human adipose tissue, NOC mRNA level negatively associated with both fasting serum insulin and homeostasis model assessment of insulin resistance, and positively associated with both adiponectin mRNA levels and circulating adiponectin levels. Taken together, these results suggest the role of Noc in the modulation of early adipogenesis as well as systemic insulin sensitivity.

Topics: 3T3-L1 Cells; Adipogenesis; Adiponectin; Adipose Tissue; Adult; Animals; Cell Proliferation; Cyclin D1; Fasting; Fibroblasts; Gene Expression; Humans; Insulin; Insulin Resistance; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitosis; Nuclear Proteins; Obesity; RNA, Messenger; Transcription Factors; Transcriptome

High-fat diets (HFDs) are known to cause obesity and are associated with breast cancer progression and metastasis. Because obesity is associated with breast cancer progression, it is important to determine whether dietary fat per se stimulates breast cancer progression in the absence of obesity. This study investigated whether an HFD increases breast cancer growth and metastasis, as well as mortality, in obesity-resistant BALB/c mice.. The 4-week-old, female BALB/c mice were fed HFD (60% kcal fat) or control diet (CD, 10% kcal fat) for 16 weeks. Subsequently, 4T1 mammary carcinoma cells were injected into the inguinal mammary fat pads of mice fed continuously on their respective diets. Cell-cycle progression, angiogenesis, and immune cells in tumor tissues, proteases and adhesion molecules in the lungs, and serum cytokine levels were analyzed with immunohistochemistry, Western blotting, and enzyme-linked immunosorbent assay (ELISA). In vitro studies were also conducted to evaluate the effects of cytokines on 4T1 cell viability, migration, and adhesion.. Spleen and gonadal fat-pad weights, tumor weight, the number and volume of tumor nodules in the lung and liver, and tumor-associated mortality were increased in the HFD group, with only slight increases in energy intake and body weight. HF feeding increased macrophage infiltration into adipose tissues, the number of lipid vacuoles and the expression of cyclin-dependent kinase (CDK)2, cyclin D1, cyclin A, Ki67, CD31, CD45, and CD68 in the tumor tissues, and elevated serum levels of complement fragment 5a (C5a), interleukin (IL)-16, macrophage colony-stimulating factor (M-CSF), soluble intercellular adhesion molecule (sICAM)-1, tissue inhibitors of metalloproteinase (TIMP)-1, leptin, and triggering receptor expressed on myeloid cells (TREM)-1. Protein levels of the urokinase-type plasminogen activator, ICAM-1, and vascular cell adhesion molecule-1 were increased, but plasminogen activator inhibitor-1 levels were decreased in the lungs of the HFD group. In vitro assays using 4T1 cells showed that sICAM-1 increased viability; TREM-1, TIMP-1, M-CSF, and sICAM-1 increased migration; and C5a, sICAM-1, IL-16, M-CSF, TIMP-1, and TREM-1 increased adhesion.. Dietary fat increases mammary tumor growth and metastasis, thereby increasing mortality in obesity-resistant mice.

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Body Weight; Cell Movement; Cell Proliferation; Complement C5a; Cyclin A; Cyclin D1; Cyclin-Dependent Kinase 2; Cytokines; Dietary Fats; Energy Intake; Female; Interleukin-16; Ki-67 Antigen; Leptin; Leukocyte Common Antigens; Liver Neoplasms; Lung; Lung Neoplasms; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Neovascularization, Pathologic; Obesity; Platelet Endothelial Cell Adhesion Molecule-1

Low levels of serum adiponectin have been reported to be associated with obesity, diabetes, and non-alcoholic steatohepatitis (NASH), as well as several malignancies. Adiponectin knockout (KO) mice have been reported to cause insulin resistance and neointimal formation of the artery. We used adiponectin KO mice fed a high fat (HF) diet, and investigated the effect of adiponectin on the progression of steatohepatitis and carcinogenesis in vivo.. Adiponectin KO mice and wild type (WT) mice were fed a HF diet or normal chow for the periods of 24 and 48 weeks. The HF diet contained 60% of calories from fat.. The adiponectin KO mice on the HF diet showed obesity, marked elevation of serum transaminase levels, and hyperlipidemia. At 24 weeks, hepatic expression of tumor necrosis factor-alpha and procollagen alpha (I) was higher in KO mice as compared with WT mice. At 48 weeks, liver triglyceride contents in KO mice on normal chow were significantly higher than those in WT mice. Hepatocyte ballooning, spotty necrosis, and pericellular fibrosis around central veins were observed in KO mice on the HF diet. The pericellular fibrosis was more severe in KO mice on the HF diet than that in WT mice (1.62% vs 1.16%, P = 0.033). Liver adenoma and hyperplastic nodules developed in a KO mouse on the HF diet at 48 weeks (12.5%, n = 1/8), whereas no tumor was detected in WT mice (n = 10).. Adiponectin may play a protective role in the progression of NASH in the early stages by suppressing tumor necrosis factor-alpha expression and liver fibrosis.

Topics: Adenoma; Adiponectin; Alanine Transaminase; Animals; Aspartate Aminotransferases; Collagen Type I; Collagen Type I, alpha 1 Chain; Cyclin D1; Dietary Fats; Disease Models, Animal; Disease Progression; Fatty Liver; Hyperlipidemias; Hyperplasia; Liver; Liver Cirrhosis, Experimental; Liver Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; RNA, Messenger; Time Factors; Triglycerides; Tumor Necrosis Factor-alpha

Sex-determining region Y-box (SOX) 6 negatively regulates glucose-stimulated insulin secretion from beta-cells and is a down-regulated transcription factor in the pancreatic islet cells of hyperinsulinemic obese mice. To determine the contribution of SOX6 to insulin resistance, we analyzed the effects of SOX6 on cell proliferation. Small interfering RNA-mediated attenuation of SOX6 expression stimulated the proliferation of insulinoma INS-1E and NIH-3T3 cells, whereas retroviral overexpression resulted in inhibition of cell growth. Quantitative real time-PCR analysis revealed that the levels of cyclin D1 transcripts were markedly decreased by SOX6 overexpression. Luciferase-reporter assay with beta-catenin showed that SOX6 suppresses cyclin D1 promoter activities. In vitro binding experiments showed that the LZ/Q domain of SOX6 physically interacts with armadillo repeats 1-4 of beta-catenin. Furthermore, chromatin immunoprecipitation assay revealed that increased SOX6 expression significantly reduced the levels of acetylated histones H3 and H4 at the cyclin D1 promoter. By using a histone deacetylase (HDAC) inhibitor and co-immunoprecipitation analysis, we showed that SOX6 suppressed cyclin D1 activities by interacting withbeta-catenin and HDAC1. The data presented suggest that SOX6 may be an important factor in obesity-related insulin resistance.

Topics: Animals; beta Catenin; Cell Division; Cell Line, Tumor; Cyclin D1; DNA-Binding Proteins; Down-Regulation; High Mobility Group Proteins; Histone Deacetylase 1; Histone Deacetylases; Histones; Humans; Hyperinsulinism; Insulin Resistance; Insulin-Secreting Cells; Insulinoma; Kidney; Leucine Zippers; Mice; NIH 3T3 Cells; Obesity; Pancreatic Neoplasms; Promoter Regions, Genetic; Protein Structure, Tertiary; Rats; SOXD Transcription Factors; Transcription Factors; Transduction, Genetic

A number of epidemiological and clinical studies have revealed that excess body weight increases the risk of postmenopausal breast cancer and also adversely affects subsequent malignant progression. To elucidate the molecular mechanisms underlying these observations, we examined mRNA expression of various genes in normal (non-cancerous) mammary gland and cancer tissue of Japanese patients with primary breast cancer, in association with their body mass index (BMI). On the basis of analysis of 106 breast cancer patients, we found that mRNA expression of insulin-like growth factor I receptor (IGF-IR) and insulin-like growth factor II (IGF-II) in the normal mammary gland showed a significant and positive association with increased BMI among postmenopausal patients. Furthermore, the positive association of increased BMI with IGF-IR mRNA expression was also found in postmenopausal breast cancer tissue, while this association was not observed among premenopausal patients. In addition, increased mRNA expression of cyclin D1 and bcl-2 was observed in association with increased mRNA levels of IGF-IR among the patients regardless of menopausal status. These findings suggest that the molecular consequence of the increased BMI is the increased expression of IGF-II and IGF-IR, resulting in development of postmenopausal breast cancer and its progression mediated through modulation of the cell cycle and apoptosis.

Topics: Adult; Aged; Body Mass Index; Breast; Breast Neoplasms; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Middle Aged; Obesity; Postmenopause; Proto-Oncogene Proteins c-bcl-2; Receptor, IGF Type 1; Risk Factors; RNA, Messenger