{"title":"Distinction in Genetic Determinants for Injury-Induced Neointimal Hyperplasia and Diet-Induced Atherosclerosis in Inbred Mice","authors":"D. Kuhel, B. Zhu, D. Witte, D. Hui","doi":"10.1161/01.ATV.0000017994.77066.75","DOIUrl":"https://doi.org/10.1161/01.ATV.0000017994.77066.75","url":null,"abstract":"Five inbred strains of mice differing in susceptibility to diet-induced atherosclerosis were compared for neointimal hyperplasia after endothelial denudation with an epoxy resin–modified catheter probe. Results showed that all animals responded similarly to the arterial injury, with increased medial area and thickness after 14 days. In contrast, a significant strain-specific difference in neointimal formation after injury was observed. The atherosclerosis-susceptible C57L/J mice were also susceptible to injury-induced neointimal hyperplasia, and the C3H mice were resistant to both forms of vascular diseases. The 129/Sv mice, which displayed an intermediate level of diet-induced atherosclerosis, also displayed an intermediate level of injury-induced neointimal hyperplasia. Interestingly, the atherosclerosis-susceptible C57BL/6 mice were resistant to neointimal hyperplasia after endothelial denudation, whereas the atherosclerosis-resistant FVB/N mice were susceptible, displaying massive neointimal hyperplasia after arterial injury. All (C57L/J×C57BL/6)F1 hybrid mice were resistant to injury-induced neointimal hyperplasia. Moreover, N2 mice generated from backcrossing the F1 hybrid mice to the susceptible C57L/J mice displayed a range of arterial response to injury, spanning the most severe to the most resistant phenotype. These results indicate that injury-induced neointimal hyperplasia and diet-induced atherosclerosis are controlled by distinct sets of genes; the former appeared to be determined by recessive genes at ≥2 loci.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76627556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Arakawa, K. Isoda, Toshimitu Ito, K. Nakajima, T. Shibuya, F. Ohsuzu
{"title":"Fluorescence Analysis of Biochemical Constituents Identifies Atherosclerotic Plaque With a Thin Fibrous Cap","authors":"K. Arakawa, K. Isoda, Toshimitu Ito, K. Nakajima, T. Shibuya, F. Ohsuzu","doi":"10.1161/01.ATV.0000017461.79231.3D","DOIUrl":"https://doi.org/10.1161/01.ATV.0000017461.79231.3D","url":null,"abstract":"Vulnerable plaque generally contains a thin fibrous cap, lipid pools, and reduced internal plaque collagen. Arterial fluorescence analysis can differentiate atherosclerotic lesions from normal arteries; however, the contribution of the lipid core to atherosclerotic arterial fluorescence remains controversial. This study aimed to identify lipid core fluorophores and to differentiate the lipid core from normal artery and atheroma. The helium-cadmium laser–induced fluorescence spectra of cadaveric arteries and known chemical constituents were recorded. Lipid core fluorescence spectra exhibited marked red shifts and broadening compared with the fluorescence spectra of normal tissue and atheroma. Similar fluorescence spectra were obtained for lipid core and oxidized low density lipoprotein, for atheroma and collagen, and for normal artery and elastin. A classification based on collagen, elastin, and oxidized low density lipoprotein spectral decomposition could discriminate the lipid core (n=29), normal artery (n=74), atheroma (n=73), and preatheroma (n=10) with 86% accuracy. Fibrous cap thickness was correlated with the spectral collagen content index (r =0.65, P <0.0001), especially at a thickness of <200 &mgr;m. We conclude that a classification algorithm based on chemical spectral decomposition can accurately classify the fluorescence spectra of normal artery, atheroma, and lipid core and may be useful in identifying vulnerable atheroma in vivo.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77819327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Folsom, N. Aleksic, Lu Wang, M. Cushman, Kenneth K. Wu, R. White
{"title":"Protein C, Antithrombin, and Venous Thromboembolism Incidence: A Prospective Population-Based Study","authors":"A. Folsom, N. Aleksic, Lu Wang, M. Cushman, Kenneth K. Wu, R. White","doi":"10.1161/01.ATV.0000017470.08363.AB","DOIUrl":"https://doi.org/10.1161/01.ATV.0000017470.08363.AB","url":null,"abstract":"Although deficiencies of protein C and antithrombin, 2 natural plasma anticoagulants, are known risk factors for venous thrombosis, population-based prospective incidence data on these associations are lacking. Venous thromboembolic events have been identified in adults in 2 longitudinal cohort studies, the Atherosclerosis Risk in Communities (ARIC) Study and the Cardiovascular Health Study (CHS). Incidence was examined in relation to prediagnostic plasma levels of protein C (ARIC Study only) and antithrombin. Over a mean of 8.1 years of follow-up, there were 130 incident venous thromboembolic events that were not due to cancer in the ARIC Study. The age-adjusted incidence was elevated 3.36-fold (95% CI 1.24 to 9.11) in the 1.1% of subjects with protein C values <2.0 mg/L compared with subjects with higher values. In contrast, in the ARIC Study and the CHS, there was no association between low plasma antithrombin and venous thromboembolism. In conclusion, in this population-based study, a low protein C, but not antithrombin, level has been determined to be associated with an increased incidence of venous thromboembolism. Attributable risk estimates suggest that low protein C levels account for ≈2.5% of venous thromboembolic events in the ARIC population.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84356413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"PAR-4 Agonist AYPGKF Stimulates Thromboxane Production by Human Platelets","authors":"R. Henriksen, V. Hanks","doi":"10.1161/01.ATV.0000014742.56572.25","DOIUrl":"https://doi.org/10.1161/01.ATV.0000014742.56572.25","url":null,"abstract":"Previous reports have indicated that thrombin-induced thromboxane production by human platelets occurs through two types of interaction between thrombin and the platelet surface. One of these interactions is with protease activated receptor(PAR)-1, the first identified thrombin receptor. These studies were undertaken to determine whether stimulation of PAR-4 also results in thromboxane production. The results show that treatment of washed human platelets with the PAR-4 agonist AYPGKF stimulates a maximum of 40% to 60% of the thromboxane produced by 100 nmol/L thrombin. Maximal thromboxane production requires approximately 1.0 mmol/L AYPGKF, despite the observation that maximal aggregation is produced by 45 &mgr;mol/L AYPGKF. Thromboxane produced by the combined stimulation of PAR-1 and PAR-4 is additive. Pretreatment of platelets with 45 &mgr;mol/L AYPGKF partially desensitizes thromboxane production in response to higher concentrations of AYPGKF and thrombin but not to stimulation by SFLLRN. PAR-4–induced stimulation is also significantly inhibited by 60 &mgr;mol/L genistein. It is concluded that activation through either PAR-1 or PAR-4 results in thromboxane production, but that stimulation of neither receptor alone produces thromboxane equivalent to that produced by 100 nmol/L thrombin. Thus, these findings demonstrate the presence of two pathways for thrombin-induced thromboxane production by platelets as proposed previously.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78715872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Jartti, T. Rönnemaa, J. Kaprio, M. Järvisalo, J. Toikka, J. Marniemi, N. Hammar, L. Alfredsson, M. Saraste, J. Hartiala, M. Koskenvuo, O. Raitakari
{"title":"Population-Based Twin Study of the Effects of Migration From Finland to Sweden on Endothelial Function and Intima-Media Thickness","authors":"L. Jartti, T. Rönnemaa, J. Kaprio, M. Järvisalo, J. Toikka, J. Marniemi, N. Hammar, L. Alfredsson, M. Saraste, J. Hartiala, M. Koskenvuo, O. Raitakari","doi":"10.1161/01.ATV.0000013313.70875.A7","DOIUrl":"https://doi.org/10.1161/01.ATV.0000013313.70875.A7","url":null,"abstract":"Finnish men have higher coronary heart disease (CHD) mortality than Swedish men do. To assess the impact of migration to a country with lower CHD mortality on subclinical atherosclerosis, we measured early functional and structural atherosclerotic vascular changes in twins discordant for migration from Finland to Sweden. Conventional CHD risk factors, flow-mediated dilatation (FMD) of the brachial artery, carotid intima-media thickness, and carotid artery compliance were measured in 74 male twin pairs (20 monozygous, 54 dizygous), aged 42 to 69 years, in which co-one twin had migrated more than 20 years ago permanently to Sweden. There were no significant differences in CHD risk factors except for diastolic blood pressure and body fat percentage, which were higher in Sweden. In all subjects, mean FMD was non-significantly higher in Sweden (5.7±4.3% vs 4.9±4.2%, P =0.22), but in monozygous twins the difference in FMD was highly significant (7.2±4.4 vs 3.7±2.9%, P =0.003). There was no significant difference in intima-media thickness or carotid artery compliance between Sweden and Finland. We conclude that in Finnish monozygous twins the endothelial function is better among the twins that have migrated to a country with lower CHD prevalence.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79498222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Symons, A. Mullick, J. Ensunsa, Amy Ma, J. Rutledge, D. Symons
{"title":"Hyperhomocysteinemia Evoked by Folate Depletion: Effects on Coronary and Carotid Arterial Function","authors":"J. Symons, A. Mullick, J. Ensunsa, Amy Ma, J. Rutledge, D. Symons","doi":"10.1161/01.ATV.0000014588.71807.0A","DOIUrl":"https://doi.org/10.1161/01.ATV.0000014588.71807.0A","url":null,"abstract":"High circulating concentrations of homocysteine (ie, hyperhomocysteinemia [Hhcy]) impair the vascular function of peripheral conduit arteries and arterioles perfusing splanchnic and skeletal muscle regions. The effects of HHcy on coronary resistance vessel function and other indexes of vascular function, ie, arterial permeability and stiffening, are unclear. We tested the hypotheses that HHcy impairs coronary resistance vessel reactivity; increases carotid arterial permeability; and initiates arterial stiffening. Male rats that consumed folate-replete (CON, n=44) or folate-deplete (HHcy, n=48) chow for 4 to 5 weeks had total plasma homocysteine concentrations of 7±2 or 58±4 &mgr;mol/L, respectively. Maximal acetylcholine-evoked relaxation (≈40% vs ≈60%) and tension development from baseline in response to nitric oxide synthase inhibition (≈20% vs ≈40%) were lower (both P <0.05) in coronary resistance vessels (≈120 &mgr;m, internal diameter) isolated from HHcy versus CON animals, respectively, whereas sodium nitroprusside-evoked relaxation and contractile responses to serotonin and potassium chloride were similar between groups. Permeability to 4400 MW and 65 000 MW fluorescently labeled (TRITC) dextran reference macromolecules (quantitative fluorescence microscopy) was ≈44% and ≈24% greater (P <0.05), respectively, in carotid arteries from HHcy versus CON rats. Maximal strain, evaluated by using a vessel elastigraph, was less (≈32% vs 42%, P <0.05) in carotid arterial segments from HHcy versus CON animals, respectively. Finally, estimates of oxidative (copper-zinc+manganese superoxide dismutase activity) and glycoxidative (pentosidine) stress were elevated (P <0.05) in arterial tissue from HHcy versus CON rats. These findings suggest that moderately severe HHcy evoked by folate-depletion impairs endothelium-dependent relaxation of coronary resistance vessels, increases carotid arterial permeability, and initiates arterial stiffening. HHcy may produce these effects by a mechanism associated with increased oxidative and glycoxidative stress.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86854942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mushtaq Ahmad, Yan Zhang, Yong Zhang, Christopher Papharalambus, R. Alexander
{"title":"Role of Isoprenylcysteine Carboxyl Methyltransferase in Tumor Necrosis Factor-&agr; Stimulation of Expression of Vascular Cell Adhesion Molecule-1 in Endothelial Cells","authors":"Mushtaq Ahmad, Yan Zhang, Yong Zhang, Christopher Papharalambus, R. Alexander","doi":"10.1161/01.ATV.0000015884.61894.DC","DOIUrl":"https://doi.org/10.1161/01.ATV.0000015884.61894.DC","url":null,"abstract":"We have previously shown that cytokine stimulation of the expression of vascular cell adhesion molecule-1 (VCAM-1), but not that of intercellular adhesion molecule-1 (ICAM-1), is redox sensitive in endothelial cells. Here, we investigated the role of isoprenylcysteine carboxyl methyltransferase (ICMTase), which methylates isoprenylated CAAX (where C indicates cysteine; A, aliphatic amino acids; and X, almost any other amino acid) proteins, including Rac1, a component of superoxide-generating NAD(P)H oxidase, in the expression of VCAM-1. Pretreatment of endothelial cells with N-acetyl-S-farnesyl-l-cysteine (AFC) or N-acetyl-S-geranylgeranyl-l-cysteine (AGGC), specific inhibitors of ICMTase, inhibited the tumor necrosis factor-&agr; (TNF-&agr;) stimulation of mRNA expression of VCAM-1 but not that of ICAM-1. Endothelial cells expressed constitutively active ICMTase, as suggested by the presence of methylated Rac1 and the methylation of AFC by the cells. TNF-&agr; stimulation of the cells significantly increased the methylation of AFC and Rac1 in endothelial cells. That ICMTase was a component of the redox-sensitive signaling pathway was also suggested by the AFC inhibition of the generation of reactive oxygen species by TNF-&agr;. Interestingly, the dominant-negative isoform of Rac1 was not selective but inhibited the TNF-&agr; stimulation of the mRNA expression of VCAM-1 and ICAM-1. Thus, ICMTase is a critical component of the redox-sensitive VCAM-1-selective signaling pathway, and it appears to activate a discrete inflammatory signaling pathway, at least in part, through the methylation of Rac1.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83420334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. V. van Etten, E. D. de Koning, M. Honing, E. Stroes, C. Gaillard, T. Rabelink
{"title":"Intensive Lipid Lowering by Statin Therapy Does Not Improve Vasoreactivity in Patients With Type 2 Diabetes","authors":"R. V. van Etten, E. D. de Koning, M. Honing, E. Stroes, C. Gaillard, T. Rabelink","doi":"10.1161/01.ATV.0000015330.64968.C4","DOIUrl":"https://doi.org/10.1161/01.ATV.0000015330.64968.C4","url":null,"abstract":"Cardiovascular disease is the most important cause of morbidity and mortality in patients with type 2 diabetes. Endothelial dysfunction predicts cardiovascular outcome. Type 2 diabetes is characterized by endothelial dysfunction, which may be caused by dyslipidemia. Statin therapy restores endothelial function in hyperlipidemic patients. Therefore, we hypothesize a beneficial effect of atorvastatin on NO-dependent vasodilation in patients with type 2 diabetes and mild dyslipidemia (low density lipoproteins >4.0 mmol/L and/or triglycerides >1.8 mmol/L). We evaluated the effect of intensive lipid lowering (4 weeks of 80 mg atorvastatin once daily) on vasoreactivity in 23 patients with type 2 diabetes by using venous occlusion plethysmography. Twenty-one control subjects were matched for age, sex, body mass index, blood pressure, and smoking habits. The ratio of blood flows in the infused (measurement [M]) and noninfused (control [C]) arm was calculated for each recording (M/C ratio), and M/C% indicates the percentage change from the baseline M/C ratio. Serotonin-induced NO-dependent vasodilation was significantly blunted (52±30 versus 102±66 M/C%, P <0.005), and nitroprusside-induced endothelium-independent vasodilation was modestly reduced (275±146 versus 391±203 M/C%, P <0.05) in patients with type 2 diabetes compared with control subjects. Despite significant reduction of total cholesterol, low density lipoproteins, and triglycerides (5.8±1.0 to 3.2±0.6 [P <0.0001], 4.1±1.1 to 1.8±0.7 [P <0.0001], and 2.2±1.3 to 1.4±0.5 [P <0.05] mmol/L, respectively), no effect on NO-dependent (59±44 M/C%) and endothelium-independent (292±202 M/C%) vasodilation was demonstrated. These data suggest that intensive lipid lowering by atorvastatin has no effect on NO availability in forearm resistance arteries in type 2 diabetic patients. Other factors, such as hyperglycemia, may be a more important contributing factor regarding impaired vasoreactivity in this patient group.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74637292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Prescott, T. McIntyre, G. Zimmerman, D. Stafforini
{"title":"Sol Sherry Lecture in Thrombosis: Molecular Events in Acute Inflammation","authors":"S. Prescott, T. McIntyre, G. Zimmerman, D. Stafforini","doi":"10.1161/01.ATV.0000016153.47693.B2","DOIUrl":"https://doi.org/10.1161/01.ATV.0000016153.47693.B2","url":null,"abstract":"The inflammatory response is characterized by a multistep molecular interaction between “signaling” cells, such as endothelial cells, and “responding” cells, such as neutrophils and monocytes. In the first step, selectins produced by signaling cells mediate the tethering of responding cells at sites of inflammation. Subsequently, an additional mediator expressed by signaling cells activates the tethered responding cells. Under pathological conditions, the same mechanism is invoked in inappropriate ways: (1) by prolonged presentation of selectins on the cell surface and (2) by the unregulated production of oxidized phospholipids that mimic the normal secondary signaling molecule, platelet-activating factor (PAF). The enzyme PAF acetylhydrolase (PAF-AH) inactivates PAF and oxidized phospholipids and constitutes an “off” switch that suppresses inflammation. Inhibition of normal PAF-AH function or inactivating mutations of the PAF-AH gene can lead to increased susceptibility to inflammatory disease. These studies have relevance to atherosclerosis and thrombosis, because inflammation is a central feature of both.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82087831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Barbier, I. Torra, Y. Duguay, C. Blanquart, J. Fruchart, C. Glineur, B. Staels
{"title":"Pleiotropic Actions of Peroxisome Proliferator-Activated Receptors in Lipid Metabolism and Atherosclerosis","authors":"O. Barbier, I. Torra, Y. Duguay, C. Blanquart, J. Fruchart, C. Glineur, B. Staels","doi":"10.1161/01.ATV.0000015598.86369.04","DOIUrl":"https://doi.org/10.1161/01.ATV.0000015598.86369.04","url":null,"abstract":"Peroxisome proliferator–activated receptors (PPARs) are nuclear receptors activated by fatty acids and derivatives. Although PPAR&agr; mediates the hypolipidemic action of fibrates, PPAR&ggr; is the receptor for the antidiabetic glitazones. PPAR&agr; is highly expressed in tissues such as liver, muscle, kidney, and heart, where it stimulates the &bgr;-oxidative degradation of fatty acids. PPAR&ggr; is predominantly expressed in adipose tissues, where it promotes adipocyte differentiation and lipid storage. PPAR&bgr;/&dgr; is expressed in a wide range of tissues, and recent findings indicate a role for this receptor in the control of adipogenesis. Pharmacological and gene-targeting studies have demonstrated a physiological role for PPARs in lipid and lipoprotein metabolism. PPAR&agr; controls plasma lipid transport by acting on triglyceride and fatty acid metabolism and by modulating bile acid synthesis and catabolism in the liver. All 3 PPARs regulate macrophage cholesterol homeostasis. By enhancing cholesterol efflux, they stimulate the critical steps of the reverse cholesterol transport pathway. As such, PPARs control plasma levels of cholesterol and triglycerides, which constitute major risk factors for coronary heart disease. Furthermore, PPAR&agr; and PPAR&ggr; regulate the expression of key proteins involved in all stages of atherogenesis, such as monocyte and lymphocyte recruitment to the arterial wall, foam cell formation, vascular inflammation, and thrombosis. Thus, by regulating gene transcription, PPARs modulate the onset and evolution of metabolic disorders predisposing to atherosclerosis and exert direct antiatherogenic actions at the level of the vascular wall.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81794086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}