transforming-growth-factor-beta and Hypercholesterolemia

A soluble form of endoglin (sEng) is known to be an extracellular domain of the full-length membrane endoglin, which is elevated during various pathological conditions related to vascular endothelium. In the current review, we tried to summarize a possible role of soluble endoglin in cardiovascular pathologies, focusing on its relation to endothelial dysfunction and cholesterol levels. We discussed sEng as a proposed biomarker of cardiovascular disease progression, cardiovascular disease treatment and endothelial dysfunction. We also addressed a potential interaction of sEng with TGF-β/eNOS or BMP-9 signaling. We suggest soluble endoglin levels to be monitored, because they reflect the progression/treatment efficacy of cardiovascular diseases related to endothelial dysfunction and hypercholesterolemia. A possible role of soluble endoglin as an inducer of endothelial dysfunction however remains to be elucidated.

Topics: Animals; Antigens, CD; Biomarkers; Cardiovascular Diseases; Endoglin; Endothelium, Vascular; Growth Differentiation Factor 2; Growth Differentiation Factors; Humans; Hypercholesterolemia; Nitric Oxide Synthase Type III; Prognosis; Receptors, Cell Surface; Signal Transduction; Transforming Growth Factor beta

Cholesterol is known to participate in atheromatous plaque formation coming from blood stream and affecting vascular endothelium in environment of elevated low-density lipoproteins (LDL). Nevertheless, the occurrence of single atheromatous plaque evidences the possibility of local lipoprotein accumulation by vascular wall without systemic increase in serum LDLs. The author hypothesizes that in the absence of hypercholesterolemia atheroma can evolve through the utilization of modified LDL and free or etherified cholesterol, that remain in media non-removed by high density lipoproteins (HDL) owing to their structural damage after local vascular wall ischemia caused by vasa vasorum disorders. Disturbances in HDL acceptor function and transport of cholesterol and modified LDL to blood circulation and further into liver are followed by local accumulation of these products in smooth muscle cells. Overloaded by lipids smooth muscle cells move through internal fenestrated membrane thus activating receptor mechanism for transmission of modified lipoproteins to monocytes and capture of endothelial membrane and amorphous lipids by them in local lipid peroxidation area. A framework for hypothesis experimental and clinical testing is suggested.

Topics: Cholesterol, HDL; Cholesterol, LDL; Coronary Artery Disease; Humans; Hypercholesterolemia; Insulin-Like Growth Factor I; Lipid Peroxidation; Muscle, Smooth; Platelet-Derived Growth Factor; Receptors, Cell Surface; Receptors, Urokinase Plasminogen Activator; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vasa Vasorum

Topics: alpha-Macroglobulins; Animals; Glomerulosclerosis, Focal Segmental; Humans; Hypercholesterolemia; Kidney Diseases; Lipoproteins, LDL; Macrophages; Protease Inhibitors; Reactive Oxygen Species; Transforming Growth Factor beta

We sought to determine whether inhibition of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase with pravastatin affects transforming growth factor-beta(1) (TGF-beta(1)) circulating levels and its production in the monocytes of hypercholesterolemic patients.. Transforming growth factor-beta(1) is a multifunctional growth factor/cytokine involved in many physiologic and pathologic processes, such as vascular remodeling and atherogenesis. Statins have been reported to have a modulatory role in cytokine expression in the monocytes of hyperlipidemic patients.. We evaluated, in a cross-over study design, plasma TGF-beta(1) levels and ex vivo TGF-beta(1) production in the monocytes of hypercholesterolemic patients before and after four to six weeks of lipid-lowering treatment with diet or diet plus 40 mg/day of pravastatin. In addition, isolated blood monocytes were subjected to pravastatin treatment and evaluated for TGF-beta(1) messenger ribonucleic acid (mRNA) expression and TGF-beta(1) in vitro production.. Lipid-lowering treatment significantly decreased total cholesterol and low-density lipoprotein cholesterol plasma levels. Pravastatin, but not a low lipid diet, induced a significant increase in TGF-beta(1) plasma levels (from 1.7 +/- 0.5 ng/ml to 3.1 +/- 1.1 ng/ml, p < 0.001) and in ex vivo monocyte production (from 1.8 +/- 0.8 ng/ml to 3.9 +/- 1.0 ng/ml, p < 0.001). The increase in TGF-beta(1) levels was not related to the changes in the lipid profile observed with pravastatin. An increase of approximately twofold in TGF-beta(1) production and in mRNA expression was also observed after in vitro treatment of human monocytes with pravastatin (5 microM). Co-incubation with mevalonate reversed the in vitro effect of pravastatin.. 3-Hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibition with pravastatin increases TGF-beta(1) plasma levels, as well as monocyte production, in hypercholesterolemic patients. The mevalonate pathway plays a role in the regulation of TGF-beta(1) expression in human monocytes. A possible implication in the biologic and clinical effects of statins can be suggested.

Topics: Anticholesteremic Agents; Cholesterol; Cross-Over Studies; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Male; Middle Aged; Monocytes; Pravastatin; Transforming Growth Factor beta; Triglycerides

In addition to suppressing breast cancer cell growth, retinoids potentiate growth inhibition in human breast cancer when tested in vitro and in vivo with tamoxifen and/or interferon. The purpose of this study was to ascertain the biologic effects of all-trans-retinoic acid (ATRA) administered alone and with tamoxifen +/- interferon and to identify the relationship between ATRA plasma concentrations and optimal biological dose (the lowest dose that produces a biological response). Three consecutive groups of 15 patients with locally advanced operable breast cancer were treated, in accordance with good clinical practice (GCP) requirements, with ATRA at 3 dose levels alone or with tamoxifen +/- alpha-interferon 2a at flat doses. After 3 weeks, the tumors were surgically removed. Biological parameters measured at the beginning (in biopsy tissue) and end (in surgical tissue) of the study were compared. The optimal biological dose for ATRA was 15 mg/m2/day. Treatments influenced tumor grade but not cell cycle kinetics (G0-G1 phase) or proliferation (Ki67 levels). ATRA induced progesterone receptors independent of dose level and co-administered drugs, but did not induce estrogen receptors when administered alone. Retinoic acid receptor (RAR)-alpha was not affected by treatment and RAR-alpha was moderately influenced whereas RAR-beta (concomitantly with transforming growth factor-beta) was induced in 33% of patients by ATRA alone. ATRA pharmacokinetics were dose- and time-dependent. Neither the ATRA + tamoxifen nor the ATRA + tamoxifen + interferon combinations potentiated the ATRA-induced biological changes. Future studies evaluating the role of RAR-beta as a biological marker of retinoid activity are warranted.

Topics: Aged; Aneuploidy; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Area Under Curve; Bone Marrow Diseases; Breast Neoplasms; Carcinoma; Drug Administration Schedule; Drug Interactions; Female; Follow-Up Studies; Headache; Humans; Hypercholesterolemia; Interferon alpha-2; Interferon-alpha; Ki-67 Antigen; Mastectomy; Middle Aged; Neoplasm Proteins; Receptors, Retinoic Acid; Receptors, Steroid; Recombinant Proteins; Safety; Tamoxifen; Transforming Growth Factor beta; Transforming Growth Factor beta1; Treatment Outcome; Tretinoin

Previous studies have shown that patients with hypercholesterolemia experience elevated levels of oxidized LDL (oxLDL), a molecule which triggers inflammation and collagenase activity. In this study we discovered novel mechanistic effects of oxLDL on tendon cells and the mediators regulating matrix remodeling by analyzing the expression and activity of related proteins and enzymes. These effects may contribute to tendon damage in patients with high cholesterol.. Isolated human tendon cells (male and female donors age 28 ± 1.4 age 37 ± 5.7, respectively) were incubated in the presence or absence of oxLDL. The influence of oxLDL on the expression level of key mRNA and proteins was examined using real time quantitative PCR, ELISA and Western blots. The activities of enzymes relevant to collagen synthesis and breakdown (lysyl oxidase and matrix metalloproteinases) were quantified using fluorometry. Finally, the isolated human tendon cells in a 3D construct were exposed to combinations of oxLDL and TGF-β to examine their interacting effects on collagen matrix remodeling.. The one-way ANOVA of gene expression indicates that key mRNAs including TGFB, COL1A1, DCN, and LOX were significantly reduced in human tendon cells by oxLDL while MMPs were increased. The oxLDL reduced the activity of LOX at 50 µg/ml, whereas conversely MMP activities were induced at 25 µg/ml (P ≤ 0.01). COL1A1 synthesis and TGF-β secretion were also inhibited (P ≤ 0.05). Adding recombinant TGF-β reversed the effects of oxLDL on the expression of collagens and LOX. OxLDL also impaired collagen matrix remodeling (P ≤ 0.01), and adding TGF-β restored the native phenotype.. Exposure to oxLDL in patients with hypercholesterolemia may adversely affect the mechanical and structural properties of tendon tissue through a direct action of oxLDL on tendon cells, including impairment of TGF-β expression. This impairment leads to disturbed matrix remodeling and synthesis, thereby potentially leading to increased risk of acute or chronic tendon injury. Our discovery may provide an opportunity for developing effective treatments for tendon injury in hypercholesterolemia patients by targeting the TGF-β pathway.

Topics: Adult; Collagen; Female; Humans; Hypercholesterolemia; Male; RNA, Messenger; Tendon Injuries; Tendons; Transforming Growth Factor beta

Non-alcoholic steatohepatitis (NASH) is associated with increased overall morbidity and mortality in non-alcoholic fatty liver disease (NAFLD) patients. Liver fibrosis is the strongest prognostic factor for clinical outcomes, liver-related mortality and liver transplantation. Currently, no single therapy or medication for NASH has been approved by the U.S. Food and Drug Administration (FDA). Oxy210, an oxysterol derivative, displays the unique property of antagonizing both Hedgehog (Hh) and transforming growth factor-beta (TGF-β) signalling in primary human hepatic stellate cells (HSC). We hypothesized that inhibition of both Hh and TGF-β signalling by Oxy210 could reduce hepatic fibrosis in NASH. In this study, we examined the therapeutic potential of Oxy210 on NASH in vivo.. We examined the effect of Oxy210 treatment on Hh and TGF-β pathways in HSC. The efficacy of Oxy210 on liver fibrosis was tested in a 'humanized' hyperlipidemic mouse model of NASH that has high relevance to human pathology.. We show that Oxy210 inhibits both Hh and TGF-β pathways in human HSC and attenuates baseline and TGF-β-induced expression of pro-fibrotic genes in vitro. Oral delivery of Oxy210 in food resulted in significant liver exposure and significantly reduced hepatic fibrosis in mice over the course of the 16-week study with no apparent safety issues. Additionally, we observed several benefits related to NASH phenotype: (a) reduced plasma pro-inflammatory cytokine and the corresponding hepatic gene expression; (b) reduced pro-fibrotic cytokine and inflammasome gene expression in the liver; (c) reduced apoptosis in the liver; (d) reduced hepatic unesterified cholesterol accumulation; and (e) reduced plasma total and unesterified cholesterol levels.. Oxy210 effectively ameliorated hepatic fibrosis and inflammation and improved hypercholesterolemia in mice. Our findings suggest that Oxy210 and related analogues are a new class of drug candidates that may serve as potential therapeutics candidates for NASH.

Topics: Animals; Hedgehog Proteins; Humans; Hypercholesterolemia; Liver Cirrhosis; Mice; Signal Transduction; Transforming Growth Factor beta; United States

Chemokine (CC-motif) receptor-like 2 (CCRL2) is a decoy receptor and regulates the local responses of the chemokine chemerin. Recently our group has shown that the functional chemerin receptor, chemokine-like receptor 1 (CMKLR1), correlates with fibrosis and non-alcoholic steatohepatitis (NASH) score in males only. In our current study, we wanted to know whether CCRL2 shows similar correlations as CMKLR1. Therefore, we analyzed the hepatic expression of CCRL2 in murine NASH and in liver tissues obtained from 85 patients with non-alcoholic fatty liver disease (NAFLD) and 33 controls. CCRL2 mRNA was not significantly changed in murine and human NASH liver. CCRL2 mRNA levels were positively correlated with inflammation, fibrosis and NASH scores in the patients. Concordantly, CCRL2 was related to the mRNA levels of F4/80, transforming growth factor beta and alpha smooth muscle actin in murine NASH. In the human cohort, CCRL2 mRNA correlated with fibrosis score and CMKLR1 mRNA in both gender. CCRL2 mRNA was induced in the liver of type 2 diabetes and hypercholesterolemic patients, but still positively correlated with fibrosis score when these patients were excluded from calculations. Human hepatic stellate cells (HSC), hepatic sinusoidal endothelial cells and Kupffer cells (KC) express CCRL2 mRNA. TNF induces CCRL2 expression in HSC and lipopolysaccharide in KC suggesting that correlations identified in NAFLD patients are partly related to the activation of these cells.

Topics: Adult; Aged; Aged, 80 and over; Animals; Body Mass Index; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Gene Expression Regulation; Hepatic Stellate Cells; Humans; Hypercholesterolemia; Kupffer Cells; Liver; Male; Mice; Middle Aged; Non-alcoholic Fatty Liver Disease; Receptors, CCR; Receptors, Chemokine; Receptors, G-Protein-Coupled; RNA, Messenger; Transforming Growth Factor beta; Young Adult

The deleterious effects of increased cadmium (Cd) serum levels on the cardiovascular system are proven by epidemiological and basic science studies. Cd exposure of animals and humans is known to impair myocardial function, possibly leading to heart failure. This study aims at investigating the effect of Cd treatment on the cardiac system with emphasis on the combined effect of Cd and high serum cholesterol levels as an important cardiovascular risk factor. Detailed analyses of Cd-induced effects on the heart of ApoE-/- mice fed a high fat diet (HFD), ApoE-/- mice fed a normal diet (ND), and C57BL/6J mice fed a ND revealed proinflammatory and fibrotic changes in the presence of cellular hypertrophy but in the absence of organ hypertrophy. Hypercholesterolemia in ApoE-/- mice alone and in combination with Cd treatment resulted in significant cardiomyocyte cell death. Based on further analyses of heart sections, we conclude that severe hypercholesterolemia in combination with ApoE-/- genotype as well as Cd treatment results in necrotic cardiomyocyte death. These data were supported by in vitro experiments showing a Cd-induced depolarization of the mitochondrial membrane and the permeabilization of the plasma membrane arguing for the occurrence of Cd-induced necrotic cell death. In summary, we were able to show for the first time that the combination of high cholesterol and Cd levels increase the risk for heart failure through cardiac fibrosis. This observation could in part be explained by the dramatically increased deposition of Cd in the hearts of ApoE-/- mice fed a HFD.

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Apolipoproteins E; Biomarkers; Body Burden; Cadmium Chloride; Cardiomyopathies; Cell Line; Chemokine CCL2; Cholesterol; Diet, High-Fat; Disease Models, Animal; Female; Fibrosis; Hypercholesterolemia; Membrane Potential, Mitochondrial; Mice, Inbred C57BL; Mice, Knockout; Mitochondria, Heart; Myocardium; Necrosis; Transforming Growth Factor beta

Hyperlipidemia is thought to be a major risk factor for the progression of renal diseases in diabetes. Recent studies have shown that lipid profiles are commonly abnormal early on type 2 diabetes mellitus (T2DM) with diabetic nephropathy. However, the early effects of triglyceride and cholesterol abnormalities on renal injury in type 1 diabetes mellitus (T1DM) are not fully understood and require reliable animal models for exploration of the underlying mechanisms. Hamster models are important tools for studying lipid metabolism because of their similarity to humans in terms of lipid utilization and high susceptibility to dietary cholesterol and fat.. Twenty-four male Golden Syrian hamsters (100-110 g) were rendered diabetes by intraperitoneal injections of streptozotocin (STZ) on consecutive 3 days at dose of 30 mg/kg, Ten days after STZ injections, hamsters with a plasma Glu concentration more than 12 mmol/L were selected as insulin deficient ones and divided into four groups (D-C, D-HF, D-HC, and D-HFHC), and fed with commercially available standard rodent chow, high-fat diet, high-cholesterol diet, high-fat and cholesterol diet respectively, for a period of four weeks.. After an induction phase, a stable model of renal injury was established with the aspects of early T1DM kidney disease, These aspects were severe hypertriglyceridemia, hypercholesterolemia, proteinuria with mesangial matrix accumulation, upgraded creatinine clearance, significant cholesterol and triglyceride deposition, and increasing glomerular surface area, thickness of basement membrane and mesangial expansion. The mRNA levels of sterol regulatory element binding protein-1c, transforming growth factors-β, plasminogen activator inhibitor-1, tumor necrosis factor-α and interleukin-6 in the D-HFHC group were significantly up-regulated compared with control groups.. This study presents a novel, non-transgenic, non-surgical method for induction of renal injury in hamsters, which is an important complement to existing diabetic models for pathophysiological studies in early acute and chronic kidney disease, especially hyperlipidemia. These data suggest that both severe hypertriglyceridemia and hypercholesterolemia can accelerate renal injury in the early development of T1DM.

Topics: Animals; Blood Glucose; Cholesterol, Dietary; Creatinine; Cricetinae; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Diet, High-Fat; Disease Models, Animal; Hypercholesterolemia; Hypertriglyceridemia; Interleukin-6; Kidney; Male; Mesocricetus; Plasminogen Activator Inhibitor 1; Proteinuria; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Up-Regulation

Most clinical trials with vitamin E could not lower cholesterol and thus, have been deemed unsuccessful. Recently, tocotrienols, isomers of vitamin E have been found to lower LDL levels. To explore if tocotrienols could be the drug target for vitamin E, rabbits were kept on cholesterol diet for 60 days supplemented with tocotrienol-α, tocotrienol-δ, and tocotrienol-γ for the last 30 days. The serum cholesterol levels (in mmol/l) were 24.4 (tocotrienol-α), 34.9 (tocotrienol-δ), 19.8 (tocotrienol-γ) vs. 39.7 (control). Left ventricular function including aortic flow and developed pressure exhibited significantly improved recovery with tocotrienol-γ and -α, but not with tocotrienol-δ. The myocardial infarct size showed a similar pattern: 33% (tocotrienol-α), 23% (tocotrienol-γ), and 47% (tocotrienol-δ). To examine the molecular mechanisms of cardioprotective effects, gene expression profile was determined using Atlas 1.2/1.2II followed by determination of gene profiles using PedQuest 8.3 software. Based on genomic profiles, the following cholesterol-related proteins were examined: FABP, TGF-β (cholesterol suppresses TGF-β), ET-1 (increased by hypercholesterolemia), SPOT 14 (linked with hypercholesterolemia), and matrix metalloproteinase (MMP) 2 and MMP9 (cholesterol regulates MMP2 and MMP9 expression) in the heart. Consistent with the cardioprotective effects of tocotrienol-α and -γ, these two isomers reduced ET-1, decreased MMP2 and MM9, increased TGF-β and reduced SPOT 14, while tocotrienol-δ had no effects. The results of the present study demonstrate that the two isomers of tocotrienols, α and γ, render the hypercholesterolemic hearts resistant to ischemic reperfusion injury by lowering several hypercholesterolemic proteins including MMP2, MMP9, ET-1, and SPOT 14 and upregulating TGF-β.

Topics: Animals; Anticholesteremic Agents; Atherosclerosis; Cardiotonic Agents; Cholesterol; Chromans; Diet, High-Fat; Endothelin-1; Female; Gene Expression; Gene Expression Profiling; Heart; Hypercholesterolemia; In Vitro Techniques; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Myocardial Reperfusion Injury; Myocardium; Rabbits; Rats; Rats, Sprague-Dawley; Receptors, Estrogen; Sex Factors; Transforming Growth Factor beta; Vitamin E

To explore the effects of mesenchymal stem cells in the formation of atherosclerosis plaque in hypercholesterolemic apoliprotein (apo) E -/ - mice. METH-ODS: ApoE -- mice mesenchymal stem cells (MSCs)were isolated and identified. Thirty ApoE -/ - mice were divided into negative control group (Neg, n = 10), positive control group (Pos, n = 10) and MSCs group ( n = 10).MSCs were injected through caudal vein into the body ofPos and MSCs groups. The plaque area of all subjects were compared, the percentage of CD4 CD25' regulatory T cells in different tissues were analyzed by FACS, proliferation response of splenocytes to mesenchymal stem cells and cyto-kines in the supernatant were determined by ELISA. RE-SULTS: Compared with controls, MSCs resulted in a significant decrease of the atherosclerotic plaques size (P <0.05), and a significant increase of CD4 CD25 regulatory T cells in spleen (P<0.05). Specific proliferation response of CD4' CD25' regulatory T cells in splenocytes to MSCswas significantly suppressed. The supernatant levels ofTGF-f3 and IL-10 in MSCs group were increased while IFN-y decreased significantly.. MSCs play an important role in regulating the inflammatory response and may significantly inhibit the formation of the atherosclerosis plaque in ApoE-'- mice.

Topics: Animals; Apolipoproteins E; CD4-Positive T-Lymphocytes; Cell Count; Cell Proliferation; Disease Progression; Gene Knockout Techniques; Hypercholesterolemia; Interleukin-10; Interleukin-2 Receptor alpha Subunit; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Mice, Knockout; Plaque, Atherosclerotic; Transforming Growth Factor beta

Lipids have been detected in the ischemic myocardium of patients' post-myocardial infarction (MI). However, their effect on the cardiac healing process remains unknown. We investigated whether intramyocardial lipids affect the signaling pathways involved in the fibrotic reparative response impairing cardiac healing post-MI.. Pigs, fed either a high-cholesterol diet (HC) or a regular-chow (NC), were subjected to experimentally-induced acute MI (90 min mid-LAD balloon occlusion) and then, upon reperfusion (R), maintained for 21 days with the same diet regime (HC/R(+) and NC/R(+), respectively). A group of hypercholesterolemic animals were sacrificed after ischemia without reperfusion (HC/R(-)). Cardiac tissue was obtained for molecular/cellular/histological analysis. Infarct size and echocardiography were assessed.. At the time of acute MI, hypercholesterolemic animals showed a higher incidence of ventricular dysrhythmias. At sacrifice, intramyocardial lipids were absent in HC/R(-). HC/R(+) showed higher lipid content (ApoB, cholesteryl-ester and triglycerides) and lower expression/activity of the TGFβ/TβRII/Smad2/3 pathway (involved in scar reparative fibrosis) than NC/R(+) in the forming scar. Collagen synthesis was accordingly reduced in the scar of HC/R(+). Infarct size was 44% larger in HC/R(+) which had higher apoptosis and lower Akt/eNOS activity in the jeopardized myocardium. Systolic function was similarly deteriorated post-MI in all animals whereas no changes were detected in diastolic-related parameters. No changes were detected in systolic parameters 21 days post-MI in NC/R(+) animals. In contrast, both systolic- and diastolic-related parameters were further deteriorated in HC/R(+) animals.. Intramyocardial lipid accumulation impairs TGFβ/TβRII/Smad2/3 signaling altering the fibrotic reparative process of the scar resulting in larger infarcts and cardiac dysfunction.

Topics: Animals; Apolipoproteins B; Apoptosis; Cholesterol Esters; Cicatrix; Collagen; Disease Models, Animal; Hypercholesterolemia; Lipid Metabolism; Myocardial Infarction; Myocardium; Myofibroblasts; Nitric Oxide Synthase Type III; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Signal Transduction; Smad2 Protein; Smad3 Protein; Swine; Time Factors; Transforming Growth Factor beta; Triglycerides; Ventricular Fibrillation; Ventricular Function, Left; Wound Healing

Dietary trans fats (TFs) have been causally linked to atherosclerosis, but the mechanism by which they cause the disease remains elusive. Suppressed transforming growth factor (TGF)-β responsiveness in aortic endothelium has been shown to play an important role in the pathogenesis of atherosclerosis in animals with hypercholesterolemia. We investigated the effects of a high TF diet on TGF-β responsiveness in aortic endothelium and integration of cholesterol in tissues. Here, we show that normal mice fed a high TF diet for 24 weeks exhibit atherosclerotic lesions and suppressed TGF-β responsiveness in aortic endothelium. The suppressed TGF-β responsiveness is evidenced by markedly reduced expression of TGF-β type I and II receptors and profoundly decreased levels of phosphorylated Smad2, an important TGF-β response indicator, in aortic endothelium. These mice exhibit greatly increased integration of cholesterol into tissue plasma membranes. These results suggest that dietary TFs cause atherosclerosis, at least in part, by suppressing TGF-β responsiveness. This effect is presumably mediated by the increased deposition of cholesterol into cellular plasma membranes in vascular tissue, as in hypercholesterolemia.

Topics: Animals; Atherosclerosis; Cholesterol; Dietary Fats; Endothelium, Vascular; Hypercholesterolemia; Liver; Male; Membrane Microdomains; Mice; Mice, Inbred C57BL; Models, Biological; Myocardium; Receptors, Transforming Growth Factor beta; Trans Fatty Acids; Transforming Growth Factor beta

The identification of the cellular and molecular pathways that mediate the development of non-alcoholic steatohepatitis is of crucial importance. Cytokines produced by liver-resident and infiltrating inflammatory cells, play a pivotal role in liver inflammation. The role of the proinflammatory cytokines IL-1α and IL-1β in steatohepatitis remains elusive.. We employed IL-1α and IL-1β-deficient mice and transplanted marrow cells to study the role of liver-resident and bone marrow-derived IL-1 in steatosis and its progression to steatohepatitis.. Atherogenic diet-induced steatohepatitis in wild-type mice was associated with 16 and 4.6 fold-elevations in mRNA levels of hepatic IL-1α and IL-1β, respectively. In mice deficient in either IL-1α or IL-1β the transformation of steatosis to steatohepatitis and liver fibrosis was markedly reduced. This protective effect in IL-1α-deficient mice was noted despite increased liver cholesterol levels. Deficiency of IL-1α markedly reduced plasma serum amyloid A and steady-state levels of mRNA coding for inflammatory genes (P-selectin, CXCL1, IL-6, and TNFα) as well as pro-fibrotic genes (MMP-9 and Collagen) and particularly a 50% decrease in TGFβ levels (p = 0.004). IL-1α mRNA levels were two-folds lower in IL-1β-deficient mice, and IL-1β transcripts were three-folds lower in IL-1α-deficient compared to wild-type mice. Hepatic cell derived IL-1α rather than from recruited bone marrow-derived cells was required for steatohepatitis development.. These data demonstrate the critical role of IL-1α and IL-1β in the transformation of steatosis to steatohepatitis and liver fibrosis in hypercholesterolemic mice. Therefore, the potential of neutralizing IL-1α and/or IL-1β to inhibit the development of steatohepatitis should be explored.

Topics: Analysis of Variance; Animals; Chemokine CXCL1; Collagen; Diet, Atherogenic; Disease Progression; Fatty Liver; Gene Expression; Hepatitis; Hypercholesterolemia; Interleukin-1; Interleukin-1alpha; Interleukin-1beta; Liver Cirrhosis; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Mice, Knockout; P-Selectin; RNA, Messenger; Serum Amyloid A Protein; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Scavenger receptors play a central role in atherosclerosis by processing oxidized lipoproteins and mediating their cellular effects. Recent studies suggested that the atherogenic state correlates with progression of chronic kidney disease (CKD); therefore, scavenger receptors are candidate mediators of renal fibrogenesis. Here, we investigated the role of CD36, a class B scavenger receptor, in a hypercholesterolemic model of CKD. We placed CD36-deficient mice and wild-type male mice on a high-fat Western diet for 7 to 8 wk and then performed either sham or unilateral ureteral obstruction surgery. CD36-deficient mice developed significantly less fibrosis compared with wild-type mice at days 3, 7, and 14 after obstruction. Compared with wild-type mice, CD36-deficient mice had significantly more interstitial macrophages at 7 d but not at 14 d. CD36-deficient mice exhibited reduced levels of activated NF-kappaB and oxidative stress (assessed by measuring fatty acid-derived hydroxyoctadecadienoic acid and protein carbonyl content) and decreased accumulation of interstitial myofibroblasts compared with wild-type mice. These data suggest that CD36 is a key modulator of proinflammatory and oxidative pathways that promote fibrogenesis in CKD.

Topics: Animals; CD36 Antigens; Chemokine CXCL10; Chemokines; Fibroblasts; Gene Expression; Hypercholesterolemia; Inflammation; Kidney; Lipoproteins; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Oxidation-Reduction; Oxidative Stress; Renal Insufficiency, Chronic; RNA, Messenger; Transforming Growth Factor beta

1. Although hormonal therapy (HT) may increase the risk of coronary heart disease (CHD) and stroke in postmenopausal women, epidemiological studies (protection in premenopausal women) suggest and experimental studies (prevention of fatty streak development in animals) demonstrate a major atheroprotective action of estradiol (E2). The understanding of the deleterious and beneficial effects of oestrogens is thus required. 2. The immuno-inflammatory system plays a key role in the development of fatty streak deposit as well as in the rupture of the atherosclerotic plaque. Although E2 favours an anti-inflammatory effect in vitro (cultured cells), it rather elicits a pro-inflammatory response in vivo involving several subpopulations of the immuno-inflammatory system, which could contribute to plaque destabilization. The functional role of several cytokines was explored in hypercholesterolemic mice. The atheroprotective effect of E2 was fully maintained in mice deficient in interferon-g or interleukin-12, as well as IL-10. In contrast, the protective effect of estradiol was abolished and even reversed in hypercholesterolemic mice given a neutralizing anti-transforming growth factor-b (TGF-b) antibody. Endothelium is another important target for E2, since it not only potentiates endothelial nitric oxide and prostacyclin production, but also controls trafficking of the populations of the immuno-inflammatory system. 3. To conclude, the respective actions of oestrogens on the cell populations involved in the pathophysiology of atherothrombosis may be influenced, among others, by the timing of HT initiation, the status of the vessel wall and, as recently demonstrated the status of the TGF-b pathway.

Topics: Animals; Atherosclerosis; Cytokines; Endothelium; Estradiol; Female; Gene Deletion; Humans; Hypercholesterolemia; Interferon-gamma; Interleukin-10; Interleukin-12; Mice; Transforming Growth Factor beta

Endoglin (CD105) is a homodimeric transmembrane glycoprotein strongly related to transforming growth factor (TGF)-beta signaling and many pathological states. In this study, we wanted to evaluate whether endoglin is expressed in normocholesterolemic and hypercholesterolemic C57BL/6J mice as well as whether it is affected by atorvastatin treatment in these mice. C57BL/6J mice were fed with chow diet or an atherogenic diet for 12 weeks after weaning. In 2 atorvastatin-treated groups, mice were fed the same diets (chow or atherogenic) as described above except atorvastatin was added at the dosage of 10 mg x kg(-1) x day(-1) for the last 8 weeks before euthanasia. Biochemical analysis of blood samples revealed that administration of atherogenic diet significantly increased levels of total cholesterol, VLDL, LDL, and decreased levels of HDL. Atorvastatin treatment resulted in a significant decrease in total cholesterol and VLDL only in mice fed by atherogenic diet. Quantitative stereological analysis revealed that atorvastatin significantly decreased endothelial expression of endoglin in C57BL/6J mice fed the atherogenic diet. In conclusion, we demonstrated that endothelial expression of endoglin is upregulated by hypercholesterolemia and decreased by the hypolipidemic effect of atorvastatin in C57BL/6J mice, suggesting that endoglin expression could be involved in atherogenesis.

Topics: Animals; Atorvastatin; Endoglin; Endothelium, Vascular; Heptanoic Acids; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred C57BL; Nitric Oxide; Platelet Endothelial Cell Adhesion Molecule-1; Pyrroles; Transforming Growth Factor beta

Atherosclerotic renovascular disease (ARVD) aggravates renal scarring more than other causes of renal artery stenosis (RAS), but the underlying pathogenic mechanisms of this potential profibrotic effect remain unclear. We tested the hypothesis that coexistence of atherosclerosis and RAS interferes with renal tissue remodeling.. Single-kidney hemodynamics and function were quantified in vivo with electron-beam computed tomography in 3 groups of pigs (n=7 each): normal pigs, pigs 12 weeks after induction of unilateral RAS (RAS group), and pigs with similar-degree RAS fed a 12-week 2% hypercholesterolemic diet (HC+RAS, simulating early ARVD). Kidneys were studied ex vivo by Western blotting and immunohistochemistry. Renal volume, renal blood flow, and glomerular filtration rate were similarly decreased in RAS and HC+RAS ischemic kidneys, accompanied by similar increased expression of profibrotic factors like transforming growth factor-beta, tissue inhibitor of metalloproteinase-1, and plasminogen activator inhibitor-1. Nevertheless, HC+RAS kidneys showed increased intrarenal fibrosis compared with RAS-only kidneys. Furthermore, expression of nuclear factor-kappaB was increased, expression of extracellular (matrix metalloproteinase-2) and intracellular (ubiquitin) protein degradation systems was decreased, and apoptosis was blunted.. Diet-induced HC superimposed on RAS accelerates the development of fibrosis in the stenotic kidney by amplifying profibrotic mechanisms and disrupting tissue remodeling. These alterations might contribute to renal disease progression in ARVD and might account for the increased propensity for end-stage renal disease.

Topics: Animals; Arteriosclerosis; Fibrosis; Glomerular Filtration Rate; Hypercholesterolemia; Kidney; Matrix Metalloproteinase 2; NF-kappa B; Plasminogen Activator Inhibitor 1; Receptors, LDL; Receptors, Oxidized LDL; Renal Artery Obstruction; Renal Circulation; Swine; Tissue Inhibitor of Metalloproteinase-1; Tomography, X-Ray Computed; Transforming Growth Factor beta

To evaluate the effect of Valeriana officinalis var latifolia(VOL) on expression of transforming growth factor beta 1 (TGF-beta 1) in hypercholesterolemic rats and study its possible mechanisms.. Dietary-induced hypercholesterolemia was induced in male Wistar rats by given 4% cholesterol and 1% cholic acid diet for 16 weeks. Changes of serum lipid, urinary albumin, renal function and Mesangial matrix index were assessed. Moreover, immunohistochemical stain for TGF-beta 1 and type IV collagen were performed.. VOL could reduce the serum levels of total cholesterol, low density lipoprotein, urinary albumin and serum creatinine. Light microscopy and immunohistochemical stain revealed that in the same time of lowing serum lipid, Mesangial matrix index was significantly reduced, accompanied by decreased expression of TGF-beta 1 and type IV collagen.. VOL has the protective effect on lipid-induced nephropathy, and the inhibition of TGF-beta 1 expression might be the mechanism of VOL on renal protection.

Topics: Administration, Oral; Animals; Drugs, Chinese Herbal; Hypercholesterolemia; Kidney Glomerulus; Male; Phytotherapy; Plant Roots; Plants, Medicinal; Rats; Rats, Wistar; Transforming Growth Factor beta; Transforming Growth Factor beta1; Valerian

Thrombus formation is a key component of the pathogenesis of restenosis after arterial balloon injury. The purpose of this study was to determine whether intimal hyperplasia could be attenuated by infusion of recombinant tissue plasminogen activator (tPA). Forty-two Kurosawa and Kusanagi hypercholesterolemic rabbits were divided into tPA (n = 20) and control (n = 22) groups, the former receiving 7 days of continuous tPA infusion (0.6 mg/kg/day) via ear veins. The walls of the common iliac arteries were injured using 2.5-mm balloon catheters and then examined histologically 7, 14, 21, and 28 days later. Cell proliferation was assessed by immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), and transforming growth factor (TGF)-beta immunohistochemistry was carried out to estimate cell proliferation and differentiation. It was observed that 28 days after balloon injury, intimal cross-sectional areas in the tPA group were significantly smaller than in controls (0.11 +/- 0.03 mm2 vs. 0.57 +/- 0.08 mm2, p < 0.01), as were ratios of the cross-sectional areas of the intima and media (0.21 +/- 0.07 vs. 1.06 +/- 0.18, p < 0.05). In addition, the numbers of PCNA-positive medial cells were significantly lower (0.06 +/- 0.01 vs. 0.36 +/- 0.08, p < 0.05) and TGF-beta-positive vessel wall areas were significantly smaller in tPA-treated animals 7 days after balloon injury (0.47 +/- 0.28% vs. 4.55 +/- 1.44%, p < 0.05). Thus infusion of tPA after arterial balloon injury appears to decrease medial cell proliferation and suppress intimal hyperplasia.

Topics: Animals; Cell Division; Female; Hemodynamics; Hypercholesterolemia; Hyperplasia; Immunohistochemistry; Male; Muscle, Smooth, Vascular; Plasminogen Activator Inhibitor 1; Proliferating Cell Nuclear Antigen; Rabbits; Recombinant Proteins; Tissue Plasminogen Activator; 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

Topics: Animals; Anticholesteremic Agents; Bone Diseases, Metabolic; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Bone Resorption; Female; Humans; Hypercholesterolemia; Male; Models, Biological; Osteoporosis; Transforming Growth Factor beta

Transforming growth factor-beta1 (TGF-1beta) has been shown to modulate both cell proliferation and the synthesis of extracellular matrix by vascular cells. This study was aimed to establish the temporal correlation between TGF-beta1 expression, the expression of the extracellular matrix protein fibronectin, and plaque development during atherogenesis of hypercholesterolemic rabbits. New Zealand White rabbits were fed with 2% cholesterol-supplemented chow for 1 week, 2 weeks, 3 weeks or 6 weeks. TGF-beta1 mRNA and protein expression was examined in serial sections of aorta by in situ hybridization and immunohistochemistry. Fibronectin expression was examined by immunohistochemistry. In the control and 1-week feeding group, the expression of TGF-beta1 mRNA and protein was not apparent. In 2-week feeding group, intimal thickening was detected in which TGF-beta1 mRNA and protein were not clearly observed, either. The 3-week and 6-week feeding groups exhibited fatty streaks in which TGF-beta1 mRNA and protein expression markedly increased as feeding proceeded. Cell type-specific staining indicated that TGF-beta1 was expressed by macrophages as well as smooth muscle cells of the fatty streaks. Immunostaining of fibronectin detected low expression levels in control, 1-week and 2-week feeding groups with pronounced upregulation in the thickened intima and the proximal media in 3-week and 6-week feeding groups. These results implicate a role for TGF-beta1 in modulating fatty streak formation and the synthesis of extracellular protein fibronectin during plaque development.

Topics: Animals; Aorta; Arteriosclerosis; Cholesterol, Dietary; Feeding Behavior; Fibronectins; Humans; Hypercholesterolemia; Immunohistochemistry; In Situ Hybridization; Male; Rabbits; Transforming Growth Factor beta

The vitronectin receptor (alphavbeta3) mediates several biological processes that are critical to the formation of a neointima after coronary interventions. Blockade of alphavbeta3 could reduce neointima formation by inhibiting smooth muscle cell migration, decreasing transforming growth factor-beta1 expression, enhancing apoptosis, or reducing neovasculature. The effects of short-term administration of Vitaxin, a humanized monoclonal antibody to alphavbeta3, on the responses to balloon injury were tested in hyperlipidemic rabbits. Balloon angioplasty was performed on the iliac arteries of male New Zealand White rabbits that were fed an atherogenic diet for 1 week before injury and until euthanization at 4 weeks. Rabbits were given either saline (control) or 1 of 2 dosing regimens of Vitaxin (high dose, 5.0 mg/kg, and low dose, 0.5 mg/kg), which were administered intra-arterially before injury and intramuscularly on days 2 and 3. High-dose and low-dose Vitaxin were equally effective in decreasing neointima formation even in the presence of hypercholesterolemia, a stimulus to alphavbeta3 expression. Vitaxin reduced transforming growth factor-beta1 and enhanced apoptosis in injured arteries. Despite these positive effects, Vitaxin administration was associated with a reduction in artery size, indicating a negative effect on remodeling. Vitaxin has a potential role in preventing intimal hyperplasia, especially if the negative effects on remodeling can be overcome, by dose adjustment or other strategies.

Topics: Angioplasty, Balloon; Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Apoptosis; Cell Movement; Cholesterol; Fluorescent Antibody Technique; Humans; Hypercholesterolemia; Hyperplasia; Iliac Artery; Male; Rabbits; Receptors, Vitronectin; Transforming Growth Factor beta; Tunica Intima

A spontaneously hypercholesterolemic Imai rat has recently been reported as a model of focal glomerulosclerosis that causes nephrotic syndrome followed by renal failure. This study was designed to determine if an oral adsorbent, AST-120, ameliorates renal lesions and TGF-beta 1 expression in the rats.. AST-120 was given orally to the Imai rats for 32 weeks, and renal function and pathology were compared between the AST-120-administered and control Imai rats.. AST-120-administered rats showed significantly lower level of blood urea nitrogen, serum creatinine, urinary protein, serum total-cholesterol, serum triglyceride, and serum and urinary indoxyl sulfate, and significantly higher levels of serum albumin and creatinine clearance than control rats. AST-120 reduced the glomerular sclerosis index, interstitial fibrosis area, and the extent of glomerular lipid deposition. Immunohistochemistry demonstrated that AST-120 reduced the expression of transforming growth factor (TGF)-beta 1 and tissue inhibitor of metalloproteinase (TIMP)-1 as well as interstitial infiltration of macrophages in the renal cortex of the Imai rats.. AST-120 prevented the progression of nephrotic syndrome and renal failure in the Imai rats by ameliorating glomerular sclerosis and interstitial fibrosis, accompanied with reduced expression of TGF-beta 1 and TIMP-1, and reduced infiltration of macrophages in the kidneys.

Topics: Administration, Oral; Animals; Blood Urea Nitrogen; Carbon; Cholesterol; Creatinine; Hypercholesterolemia; Immunohistochemistry; Kidney; Kidney Glomerulus; Male; Oxides; Proteinuria; Rats; Transforming Growth Factor beta; Triglycerides

Uninephrectomized rats with diet-induced hypercholesterolemia develop interstitial inflammation and fibrosis after 8 to 12 weeks. Fibrosis has been associated with the accumulation of lipid peroxidation products within the tubulointerstitium, along with increased renal mRNA levels for transforming growth factor beta-1 (TCF-beta 1), some matrix proteins, and the tissue inhibitor of metalloproteinases (TIMP-1). However, mRNA levels for urokinase-type plasminogen activator (uPA) have been found to be decreased. The purpose of the present study was to determine whether antioxidant therapy could attenuate interstitial fibrosis in hypercholesterolemic rats and to determine changes in the pattern of renal gene expression induced by antioxidant therapy. Three groups of uninephrectomized rats were studied after 12 weeks of feeding standard rat chow, an atherogenic diet (standard chow plus 4% cholesterol/1% cholic acid), or an atherogenic diet supplemented with high doses of the antioxidants probucol and vitamin E. Rats fed the atherogenic diet developed hypercholesterolemia and a 56% increase in total kidney collagen compared with rats fed standard chow. In comparison, the hypercholesterolemic rats treated with antioxidants had normal levels of renal lipid peroxidation products and a normal kidney collagen content. In contrast, there were no significant differences in urinary albumin excretion rates or the number of interstitial macrophages between the two hypercholesterolemic groups. Compared with the untreated hypercholesterolemic group, antioxidant therapy induced significant reductions in renal mRNA levels for procollagen III (to 60% of untreated levels), collagen IV (60%), and TIMP-1 (20%), while uPA levels were significantly increased (to 210%). Paradoxically, antioxidant therapy was associated with a significant increase in renal TGF-beta 1 mRNA levels (to 150%), although TGF-beta 1 protein expression shifted from interstitial to tubular epithelial cells in predominance. The results of the present study demonstrate the efficiency of antioxidant therapy in preventing renal interstitial fibrosis in hypercholesterolemic rats with a single kidney. Based on changes in renal gene expression at the mRNA level, impaired matrix protein synthesis and increased intrarenal activity of the metalloproteinases and uPA/plasmin may play a role in the attenuation of fibrosis.

Topics: Animals; Antioxidants; Collagen; Diet, Atherogenic; Endopeptidases; Extracellular Matrix Proteins; Female; Fibrosis; Gene Expression; Hypercholesterolemia; Kidney; Lipid Peroxidation; Nephritis, Interstitial; Oxidation-Reduction; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta; Urokinase-Type Plasminogen Activator

Plasminogen activator inhibitor-1 (PAI-1), the major physiologic inhibitor of tissue-type plasminogen activator and urokinase, is abundantly expressed in atherosclerotic vascular wall. To determine the role of PAI-1 in vascular wall, we have used a novel inhibitor of PAI-1, (3E, 4E)-3-benzylidene-4-(3,4,5-trimethoxy-benzylidene) -pyrrolidine-2,5-dione (T-686). T-686 was given to human vascular endothelial cells in vitro and to rabbits subjected to high cholesterol diet and mechanical injury in vivo. T-686 attenuated the augmentation of PAI-1 antigen accumulation induced by transforming growth factor beta in conditioned medium from the human umbilical vein endothelial cells. In rabbits with aortic atherosclerosis induced by hypercholesterolemia and implantation of indwelling plastic tubing, oral administration of T-686 (30mg/kg body weight/day) for 8 weeks attenuated the increase in plasma PAI-1 activity induced by vascular injury without decreasing blood triglyceride and cholesterol. This was accompanied by the reduction in aortic PAI-1 mRNA expression and the inhibition of development of atherosclerosis lesions. Thus, T-686 not only decreased PAI-1 synthesis in vascular cells in vitro but also protected against the development of vascular lesions in vivo. This compound may be useful in defining the role of PAI-1 in atherothrombotic states.

Topics: Animals; Aorta; Arteriosclerosis; Benzylidene Compounds; Cells, Cultured; Disease Models, Animal; Endothelium, Vascular; Humans; Hypercholesterolemia; Lipids; Plasminogen Activator Inhibitor 1; Rabbits; RNA, Messenger; Succinimides; Tissue Plasminogen Activator; Transforming Growth Factor beta; Umbilical Veins

Abnormalities in lipid metabolism appear to play a pathogenic role in progressive renal disease. To elucidate the cellular and molecular basis of renal interstitial fibrosis in uninephrectomized rats with diet-induced hypercholesterolemia, we fed experimental rats with standard rat chow supplemented with 4% cholesterol and 1% cholic acid. Control rats were fed an isocaloric diet. Groups of 7 control and 7 experimental rats were killed after 4, 8, and 12 weeks. Hypercholesterolemic rats developed albuminuria; serum creatinine was elevated at 12 weeks. By 12 weeks numerous oil red O-positive cells were present throughout the interstitium and to a lesser extent in tubules. Total renal lipid-peroxidation products were significantly increased (172 +/- 15, 198 +/- 28, and 197 +/- 13 mmol malondialdehyde/kidney at 4, 8, and 12 weeks vs. 123 +/- 17, 144 +/- 6, and 125 +/- 10 mmol in controls). Immunostaining revealed oxidatively modified lipoproteins within tubular and interstitial cells. The interstitial disease was characterized by an interstitial infiltrate of monocytes. Significant increases were detected in renal cortical mRNA levels for monocyte chemoattractant protein-1 (MCP-1), osteopontin, and vascular cell adhesion molecule-1 (VCAM-1), associated with changes in the pattern of immunostaining for each encoded proteins. Total kidney collagen was significantly increased at 12 weeks (9.8 +/- 0.9 mg/kidney vs. 7.8 +/- 0.9 mg in controls). At 12 weeks there was a significant increase in interstitial immunostaining for collagen I, collagen III, collagen IV, fibronectin and tenascin. A significant threefold increase in renal cortical mRNA levels for transforming growth factor beta-1 (TGF-beta 1) at 4 and 12 weeks was associated with the appearance of TGF-beta 1-positive interstitial cells. Renal matrix protein mRNA levels were measured at 4, 8, and 12 weeks. The only statistically significant elevations were procollagen alpha 1(I) and procollagen alpha 1(III) at weeks 8 and 12. In contrast, renal cortical mRNA levels for the tissue inhibitor of metalloproteinases-1 (TIMP-1) were significantly increased at 4, 8 and 12 weeks (1.4 +/- 0.5, 2.7 +/- 0.9 and 2.7 +/- 1.4 arbitrary densitometric units, respectively, vs. 1.0 +/- 0.4, 1.0 +/- 0.5 and 1.0 +/- 0.4 units for controls), and urokinase-type plasminogen activator (muPA) mRNA levels were significantly decreased at 4, 8, and 12 weeks (0.4 +/- 0.1 arbitrary densitometric units for all three experimental groups vs.

Topics: Actins; Animals; Biomarkers; Chemokine CCL2; Cholesterol, Dietary; Diet, Atherogenic; Extracellular Matrix Proteins; Female; Fibrosis; Glycoproteins; Hypercholesterolemia; Kidney; Lipid Metabolism; Monocytes; Nephrectomy; Nephritis, Interstitial; Protease Inhibitors; Rats; Rats, Sprague-Dawley; RNA; Time Factors; Tissue Inhibitor of Metalloproteinases; Transforming Growth Factor beta; Urokinase-Type Plasminogen Activator; Vascular Cell Adhesion Molecule-1

Evidence from several sources suggests that important interactions occur between platelets and low-density lipoproteins. This study was undertaken to find out if diet-induced hypercholesterolaemia affects the growth factor content in circulating platelets. Minipigs were fed either normal diet supplemented with 2% cholesterol (n = 12) or normal diet alone (n = 12). After 4 months, mean platelet volume was significantly lower (P < 0.05) and monocyte count was significantly higher (P < 0.05) in the cholesterol group. Serum and intraplatelet levels of platelet-derived growth factor (BB homodimer) and transforming growth factor beta 1 were statistically unchanged after diet. Hypercholesterolaemia did not affect the proliferative effect of either serum or platelet lysates on porcine vascular smooth muscle cells and Swiss-3T3 cells in culture. A significant positive correlation between Swiss-3T3 and smooth muscle cell proliferation was present in both groups. These results suggest that the atherosclerosis-promoting effect of hypercholesterolaemia cannot be explained by its direct effect on smooth muscle cell proliferation or by changes in serum or intraplatelet concentrations of growth factors.

Topics: 3T3 Cells; Animals; Blood Cell Count; Blood Platelets; Hypercholesterolemia; Male; Mice; Platelet-Derived Growth Factor; Swine; Swine, Miniature; Transforming Growth Factor beta

Increasing evidence suggests that lipids may be important modulators of progressive glomerular injury. We previously reported the long-term glomerular changes in rats with dietary-induced hypercholesterolemia. In this work, we evaluated the early glomerular changes induced by hypercholesterolemia that precede the development of glomerulosclerosis. In cholesterol-fed rats, an early macrophage influx was observed. This was associated with an increase in glomerular size, mesangial matrix expansion, lipid deposits, and foam cell formation. Immunohistochemical techniques showed that type IV collagen, fibronectin, and laminin were increased in cholesterol-fed rats. The mRNA expression for the alpha 1 chain of type IV collagen and an inhibitor of type IV collagenase were increased, suggesting that both increased synthesis and reduced degradation may be involved in cholesterol-induced mesangial matrix accumulation. The glomerular mRNA expression of transforming growth factor-beta 1 was also upregulated, suggesting that transforming growth factor-beta 1 could be an important mediator for mesangial matrix accumulation in hypercholesterolemic states. The early cholesterol-induced changes in the glomerulus are reminiscent in many respects to the process leading to glomerulosclerosis in the vessel wall.

Topics: Animals; Blotting, Northern; Cholesterol, Dietary; Collagen; Extracellular Matrix; Fibronectins; Fluorescent Antibody Technique; Foam Cells; Glomerular Mesangium; Glycoproteins; Hypercholesterolemia; Kidney Glomerulus; Laminin; Macrophages; Matrix Metalloproteinase Inhibitors; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tissue Inhibitor of Metalloproteinases; Transforming Growth Factor beta; Up-Regulation

Several cytokines have been identified as markers of early atherosclerotic disease during vascular injury and remodelling. Of particular importance, transforming growth factor-beta (TGF-beta 1) has been found to be crucial in promoting connective tissue deposition resulting in both intimal and medial hyperplasia. However, the expression of TGF-beta 1 and beta 2 during cholesterol feeding in the Watanabe rabbit, an established model of hypercholesterolemia, has not been evaluated. Accordingly, we examined the expression of TGF-beta 1 and beta 2 signal from aortic segments of 10 heterozygous Watanabe rabbits with the use of reverse transcription-polymerase chain reaction (RT-PCR) amplification during normal non-supplemental diet and during 0.5% supplemental cholesterol feeding for a period of two months. TGF-beta transcripts from the aortic tissue were quantified at the end of the feeding interval. For Watanabe rabbits fed regular chow, the expression of both TGF-beta 1 and beta 2 is reduced in the aortic arch as compared with the descending aorta. In contrast, Watanabe rabbits fed high cholesterol diets manifested a differential expression of TGF-beta isoforms depending on the spatial location within the aorta. In the aortic arch, increased transcript signals for both TGF-beta 1 and beta 2 were noted as compared with rabbits on normal chow. The lesions found in the aortic arch are typified by abundant foam cells and proliferating smooth muscle cells. Analysis of the TGF-beta 1 and 2 profile on these same cell elements in vitro results in a similar expression of increased mRNA isoforms for TGF-beta 1 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Aorta, Thoracic; Base Sequence; Cells, Cultured; Cholesterol, Dietary; Diet, Atherogenic; Disease Models, Animal; Hypercholesterolemia; Macrophages; Male; Mice; Molecular Sequence Data; Muscle, Smooth, Vascular; Polymerase Chain Reaction; Rabbits; Rats; Solubility; Transforming Growth Factor beta

Macrophage infiltration into the glomerular mesangium is a prominent feature of various glomerulopathies. Recent evidence suggests that infiltrating macrophages may play a role in propagating initial glomerular injury to the development of glomerulosclerosis via transforming growth factor-beta (TGF-beta)-stimulating matrix accumulation. Rats with the acute puromycin aminonucleoside (PA) nephrosis exhibit an elevated gene expression of glomerular TGF-beta 1; however, the cellular origin of this upregulation is unknown. Using polymerase chain reaction (PCR), we detected that the TGF-beta 1 isoform is expressed in glomerular macrophages isolated from experimental rats made hypercholesterolemic by either diet or by induction of PA nephrosis. Peritoneal macrophages from nephrotic or dietary-hypercholesterolemic animals also exhibited a significant increment in the expression of TGF-beta 1 mRNA on Northern analysis, in contrast to similar cells obtained from normal control rats. PCR analysis of glomerular RNA also detected the expression of the TGF-beta 2 mRNA isoform. TGF-beta 2 mRNA expression was not observed in isolated glomerular macrophages from either glomeruli of PA-nephrotic rats or from glomeruli of animals with dietary hypercholesterolemia. Expression of the TGF-beta 3 mRNA isoform was only observed by PCR in J774 A.1 cells. Thus the as a cellular source for the enhanced expression of TGF-beta 1 during the acute nephrotic phase of our toxic, progressive glomerulopathy model and within several days of inducing only hypercholesterolemia by dietary means.

Topics: Albuminuria; Animals; Base Sequence; Cholesterol, Dietary; Gene Expression; Hypercholesterolemia; Immunohistochemistry; Kidney Glomerulus; Lipids; Macrophages; Male; Molecular Sequence Data; Nephrosis; Polymerase Chain Reaction; Puromycin Aminonucleoside; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta

Hypercholesterolemia aggravates experimental progressive glomerular injury. Evidence suggests the infiltrating glomerular macrophage (M phi) is a potential effector mechanism for the noxious effects of hypercholesterolemia. Because transforming growth factor (TGF)-beta 1 is secreted by activated M phi s and also stimulates fibronectin production by glomerular cells, we evaluated the kinetics of gene expression for these moieties in glomeruli isolated from nephrotic rats at 3, 7, 11, and 42 days after the delivery of puromycin aminonucleoside (PA). We also assessed whether cholesterol feeding, which raises the glomerular M phi number, alters the glomerular mRNA levels for TGF-beta 1 and fibronectin. Glomerular mRNA levels for TGF-beta 1 and fibronectin in nephrotic rats exhibited a biphasic temporal pattern, decreasing significantly below control at 3 and 7 days after PA but increasing significantly at 11 and 42 days after PA. The upregulated gene expression for TGF-beta 1 and fibronectin at 11 days after PA temporally corresponded to the phase of mesangial M phi infiltration in this model. Cholesterol feeding to both normal and nephrotic rats significantly increased glomerular TGF-beta 1 and fibronectin mRNA levels at 11 days after PA. Immunohistochemical labeling for M phi s and intracellular TGF-beta 1 demonstrated both mesangial and cortical interstitial localization with the TGF-beta1-positive cells possessing M phi nuclear morphology. These findings identify a novel interaction between hypercholesterolemia, augmented glomerular M phi accumulation, and upregulated glomerular TGF-beta 1 and fibronectin gene expression. These perturbations within the acutely injured glomerulus constitute an early pathobiological determinant for the later development of mesangial matrix expansion and glomerulosclerosis.

Topics: Albuminuria; Animals; Cholesterol; Cholic Acids; Extracellular Matrix; Fibronectins; Food, Fortified; Gene Expression; Hypercholesterolemia; Immunohistochemistry; Kidney Glomerulus; Lipids; Macrophages; Male; Nephrosis; Puromycin Aminonucleoside; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta; Up-Regulation

Macrophage/smooth muscle cell interactions play a role in atherogenesis and foreign body reactions to biomaterials. This study investigates the effect of a hypercholesterolemic diet on the ability of smooth muscle cells (SMCs) to respond to monokines which are produced in response to hypercholesterolemia, biomaterials or both. Peritoneal macrophages were harvested from rabbits fed either a normal (M phi NL) or a 2% cholesterol/6% peanut oil diet (M phi ATH) (plasma cholesterol 2840 vs 42.3 [p less than 0.005]). The macrophages were then cultured in the presence of either 1) polyglactin 910 (PG910), 2) Dacron, or 3) no biomaterial (control), and the media collected and pooled by week for the smooth muscle cell mitogenesis assays. Rabbit aortic smooth muscle cells were harvested and cultured from the same two groups of rabbits (SMCNL or SMCATH), quiesced in serum free media (48 h) followed by addition of the test media and 3H-TdR. The addition of either biomaterial to M phi NL-conditioned media increased 3H-TdR incorporation in both smooth muscle lines as compared to controls. PG910 resulted in significantly higher 3H-TdR incorporation than Dacron (weeks 3-5, p less than 0.005). The addition of either biomaterial to M phi ATH also increased 3H-TdR incorporation in both smooth muscle cell lines, however, the magnitude of the response was decreased as compared to the M phi NL-conditioned media in both cell lines (p less than 0.001 for either SMC line). In contrast to the M phi NL-conditioned media, the addition of Dacron to M phi ATH resulted in the highest level of 3H-TdR incorporation in both cell lines as compared to the media without biomaterial. The SMCNL had a higher response to both the monokines in conditioned media (2-fold) and to fetal bovine serum (3-fold) than the SMCATH (p less than 0.001). Although there is a generalized decrease in release of mitogens active on SMCs from M phi ATH, the M phi ATH exposed to Dacron release increased amounts of mitogenic factors, most active on the SMCATH cell line. A common mode of failure of small diameter Dacron grafts in man is pseudointimal hyperplasia, and it is inviting to postulate that the Dacron/macrophage/smooth muscle cell interactions in this atherosclerotic group of patients plays a role in the pathogenesis of this lesion.

Topics: Animals; Aorta; Arteriosclerosis; Cell Division; Cell Line; Cells, Cultured; DNA Replication; Hypercholesterolemia; Kinetics; Macrophages; Mink; Monokines; Muscle, Smooth, Vascular; Organ Culture Techniques; Rabbits; Transforming Growth Factor beta