摘要
糖尿病(Diabetes Mellitus,DM)患者容易发生动脉粥样硬化(atherosclerosis,AS),且时间早,进展快、范围广、预后差,即所谓加速性AS,是DM致死、致残的重要原因。研究表明,持久的高血糖状态可导致DM患者体内许多结构和功能蛋白质、脂质甚至核酸发生糖基化,经过一系列非酶促反应,即Maillard反应,形成Schiff碱,经Amadori反应重排后,最终形成具有高度活性、结构多样的糖基化终产物(advanced glycation end products,AGEs),后者通过与细胞表面特异性AGEs受体(receptor for AGEs,RAGE)相互作用而发挥一系列的血管病理作用,加速糖尿病性AS的发生、发展。泡沫细胞形成是AS发生的早期事件和关键环节,胆固醇酯在巨噬细胞中大量沉积则是泡沫细胞形成的重要原因,这一过程受清道夫受体、酰基辅酶A:胆固醇酰基转移酶-1(acyl-coenzyme A: cholesterolcyl transferase-1,ACAT-1)和ATP结合盒转运子(ATP-binding cassette transporter A1,ABCA1)共同调节。ACAT-1是细胞内唯一催化游离胆固醇和长链脂肪酸酯化形成胆固醇酯的酶,在单核/巨噬细胞中主要以ACAT-1形式存在。病理条件下,巨噬细胞ACAT-1高表达,导致细胞内胆固醇酯大量堆积而形成泡沫细胞,这就是AS的早期病变,可见ACAT-1是巨噬细胞源性泡沫细胞形成的主要介导者。然而,有关AGEs促发巨噬细胞源性泡沫细胞形成的作用是否与巨噬细胞ACAT-1的表达变化有关,目前尚不清楚。
过氧化物酶体增殖物激活受体γ(peroxisome proliferator activated receptor-γ, PPARγ)是一类由配体活化的核转录因子,属于核受体超家族成员,与脂肪细胞分化、炎症反应、胰岛素敏感性、细胞周期调节、AS及肿瘤等关系密切。研究表明,PPARγ在单核细胞分化为巨噬细胞时表达,在维持巨噬细胞脂质代谢平衡过程中占有主导地位,但目前对于核受体PPARγ在加速性AS发生、发展中的作用尚有争议。此外,核受体PPARγ是否调节着巨噬细胞ACAT-1的转录尚未见报道。
目的
本研究试图从AGEs影响巨噬细胞ACAT-1和PPARγ及其下游基因表达这一角度,阐明AGEs促发AS巨噬细胞源性泡沫细胞形成的作用机制。为此,我们以体外培养的THP-1细胞为实验对象,进行以下研究:1、AGEs对巨噬细胞ACAT-1基因表达的影响; 2、AGEs对巨噬细胞核受体PPARγ及其下游SR-A基因表达的影响;3、研究比较巨噬细胞ACAT-1与PPARγ之间的相关性;4、通过观察PPARγ的合成型配体罗格列酮对AGEs诱导的巨噬细胞ACAT-1表达的作用,探讨PPARγ活化在糖尿病性AS中发挥血管保护作用可能的机制。
方法
1.按标准的方法用D-葡萄糖和牛血清白蛋白(BSA)共同孵育12周制备糖基化牛血清白蛋白(AGE-BSA),即AGEs。
2. THP-1单核细胞培养于RPMI1640完全培养液中,于37℃、5%CO2培养箱中静置培养,每隔3～5天传代一次。用终浓度为0.1μM的PMA诱导THP-1单核细胞72h,使其分化成巨噬细胞。
3.分别用浓度为50、100、200和400mg/L的AGE-BSA干预巨噬细胞24h,以100mg/L BSA作为对照组。同时用200mg/L AGE-BSA分别处理细胞0、12、24、36h和48h。
4.运用免疫细胞化学方法检测巨噬细胞PPARγ及其下游SR-A的表达,了解AGEs对巨噬细胞PPARγ和SR-A蛋白表达的影响。
5.运用RT-PCR和Western blot方法检测巨噬细胞ACAT-1和PPARγ基因和蛋白的表达,同使用EMSA检测巨噬细胞PPARγ的DNA结合活性,了解AGEs对巨噬细胞ACAT-1和PPARγ表达的影响。
6.分别以PPARγ激动剂和PPARγ抗体刺激巨噬细胞,运用RT-PCR和Western blot方法检测巨噬细胞PPARγ和ACAT-1基因和蛋白的表达情况,明确巨噬细胞ACAT-1和PPARγ之间的相关性。
7.以PPARγ激动剂罗格列酮预处理巨噬细胞4h,再用AGE-BSA刺激巨噬细胞,运用RT-PCR和Western blot方法检测巨噬细胞ACAT-1基因和蛋白的表达,明确罗格列酮对AGEs诱导的巨噬细胞ACAT-1表达的影响。
结果
1.荧光分光光度计上分别测定AGE-BSA和BSA的荧光值,AGE-BSA为180.5荧光单位/mg蛋白,BSA为2.98荧光单位/mg蛋白。
2.经0.1μmol/L PMA诱导72h后,THP-1细胞形态由圆形变为梭形、椭圆形或不规则型,由悬浮状态向贴壁状态转化,细胞体积增大,呈阿米巴样贴壁生长,伸出伪足,富含颗粒,具有巨噬细胞的特点,转化率超过85%。
3.与对照组相比,AGE-BSA可使巨噬细胞ACAT-1 mRNA和蛋白的表达水平显著上调(P<0.05),而核受体PPARγmRNA和蛋白的表达水平则显著降低(P<0.05),二者均呈现良好的浓度和时间依赖性。此外,EMSA结果显示,AGE-BSA还可浓度依赖性地抑制巨噬细胞PPARγ的DNA结合活性(P<0.05)。
4.免疫细胞化学法结果显示,AGE-BSA显著抑制巨噬细胞PPARγ表达的同时,还可显著上调SR-A蛋白的表达水平(P<0.05)。
5.与对照组相比,PPARγ激动剂刺激后,巨噬细胞PPARγmRNA和蛋白的表达量明显增加,而ACAT-1 mRNA和蛋白的表达量则明显降低(P<0.05);相反,PPARγ抗体刺激后,巨噬细胞PPARγmRNA和蛋白的表达量显著降低,而ACAT-1 mRNA和蛋白的表达量则显著增加(P<0.05)。
6.给予1μM、5μM和10μM的罗格列酮预处理后,AGE-BSA诱导的巨噬细胞ACAT-1 mRNA和蛋白的表达量均较对照组显著下降(P<0.05)。
结论
1. AGE-BSA可明显增强巨噬细胞ACAT-1 mRNA和蛋白的表达水平,呈浓度和时间依赖性。
2. AGE-BSA不仅可显著下调巨噬细胞核受体PPARγmRNA和蛋白的表达水平,还可浓度依赖性地抑制PPARγ的DNA结合活性。
3. AGE-BSA通过上调巨噬细胞表面SR-A蛋白的表达水平,促进巨噬细胞摄取脂质,有利于泡沫细胞形成。
4. PPARγ配体可使巨噬细胞PPARγ表达增强,ACAT-1表达减弱;而PPARγ抗体则使PPARγ表达减弱,ACAT-1表达增强,说明PPARγ与ACAT-1之间存在明显的负相关性。
5. PPARγ特异性激动剂--罗格列酮可显著抑制AGE-BSA诱导的巨噬细胞ACAT-1 mRNA和蛋白的表达水平,此效应在一定浓度范围内呈浓度依赖性,表明PPARγ活化可通过转录调节ACAT-1的表达,从而阻止胆固醇酯在巨噬细胞内大量蓄积,最终抑制AGEs促发的巨噬细胞源性泡沫细胞形成。
Diabetes mellitus is a comman, frequently-occurring disease and its chronic vascular complications such as atherosclerosis are the principal cause of morbidity and mortality in diabetic patients. It has been showed that advanced glycation end products (AGEs) play an important role in the pathogenesis and progression of accelerated atherosclerosis. AGEs are a group of nonreversible and poisonous products formed by nonenzymatic glycation of glucose with protein and lipids under hyperglycemia condition. It not only directly results in the structure and fuction changes of the tissues in which AGEs deposited but also can interact with receptor for AGEs (RAGE), a member of the immunoglobulin superfamily of cell surface molecules which express in range of cells including endothelial cell, smooth muscle cell and mononuclear phagocytes, to result in dysfunction and lesion of the cells and play a key role in initiating vasculopathy.
Atherosclerosis is an inflammatory disease process with increased plasma low density lipoprotein-cholesterol level. Monocyte/macrophages contribute to the development of lesions by accumulation of cholesterol esters and the formation of foam cells. As we know, macrophage foam cell formation, characterized by cholesterol ester accumulation, is modulated by scavenger receptor (cholesterol influx), acyl-coenzyme A: cholesterol acyltransferase-1 (ACAT-1; storage cholesterol ester converted from free cholesterol), and ATP-binding cassette transporter A1 (cholesterol efflux). ACAT catalyzes the formation of cholesteryl esters from cholesterol and long chain fatty acyl coenzyme A. ACAT is believed to play significant roles in lipoprotein assembly and in dietary cholesterol absorption. ACAT-1 and ACAT-2 are two subtypes of ACAT gene family. ACAT-1 protein is present at high levels in macrophages and hormone-producing cells. ACAT-1 gene expression is up-regulated in human monocytes during differentiation and foam cell formation. Under pathological conditions, accumulation of cholesteryl esters produced by ACAT-l can promote foam cell formation in atherosclerotic lesions. However, it’s still unknown the molecular mechanism of ACAT-1 gene expression, regulation and its signal transduction induced by AGEs in macrophages.
Peroxisome proliferator-activated receptor-γ(PPARγ) is a member of nuclear transcription factors and involes in multiple physiological or pathophysiological process including adipocyte differentiation, inflammation, insulin sensitivity, cell cycle regulation and cancers. It is widely accepted that PPARγis a key regulater during the development of atherosclerosis. The interests have focused on the role of PPARγin modulating macrophage cholesterol and lipid homeostasis.
Objectives:
In this study, THP-1 macrophages were exposed to AGEs-modified bovine serum albumin (AGE-BSA) at different concentration for 24 hours and at a concentration of 200mg/L for different time to investigate the effects of AGEs on the expression of ACAT-1, PPARγand SR-A, which is in favour of clarifying the mechanism of AGEs promoting macrophage-derived foam cell formation. In additional, we investigate the effects of rosiglitazone, a synthetic PPARγligand, on the expression of ACAT-1 induced by AGEs in THP-1 macrophages. The molecular mechanisms of AGEs accelerating atherosclerosis in diabetic patients were proposed and the protective effects of PPARγactivation during foam formation were discussed.
Methods:
1. AGE-BSA was prepared by the methods as described previously. Briefly, AGE-BSA was made by incubating BSA with 50 mM D-glucose in 5% CO2/95% air at 37°C for 12 wk in a 10 mM PBS, pH 7.4, in the presence of 100 units/ml penicillin, and 100 mg/ml streptomycin. Unincorporated glucose was removed by dialysis overnight against 1×PBS.
2. The human monocytic leukemia cell line, THP-1 cells were cultured in RPMI1640 medium supplemented with 10% FBS, 100 U/ml penicillin, and 100 mg/ml streptomycin. In order to induce phagocytic differentiation, THP-1 cells were cultured in the presence of 0.1μM PMA for 72 h.
3. THP-1 macrophages were exposed to AGE-BSA at different concentrations (50, 100, 200 and 400 mg/L) for 24h, and exposed to AGE-BSA at a concentration of 200mg/L for 0,12,24,36 h and 48 h.
4. Immunocytochemistry was used to examine the expression levels of proteins for PPARγand SR-A in AGEs-treated macrophages.
5. The expression levels of mRNA and proteins for ACAT-1 and PPARγin AGEs-treated macrophages were semi-quantified by RT-PCR and Western blot, respectively. And the transcriptional activity of PPARγin AGEs-treated macrophages was determined by electrophoretic mobility shift assay (EMSA).
6. THP-1 macrophages were incubated respectively with PPARγagonist rosiglitazone and anti-PPARγmonoclonal antibody. The expression levels of mRNA and proteins for ACAT-1 and PPARγwere detected by RT-PCR and Western blot.
7. THP-1 macrophages were pretreated by rosiglitazone for 4h and then incubated with AGE-BSA at a concentration of 200mg/L for 24h. The expression levels of mRNA and proteins for ACAT-1 were detected by RT-PCR and Western blot.
Results:
1. AGEs-protein specific fluorescence determinations were performed by measuring emission at 450nm on excitation at 390nm using a Fluorescence spectrophotometer. AGE-BSA contained 180.5 fluorescence U/mg protein while unmodified BSA contained 2.9 fluorescence U/mg protein.
2. About 85% of THP-1 cells incubated with PMA (0.1μM) for 72h stopped proliferation and differentiated into macrophages. These macrophages containing granules grew on the wall of culture flask just like ameba cells and extended pseudopods.
3. Compared with the control BSA group, AGE-BSA significantly upregulated the levels of mRNA and proteins for ACAT-1 but downregulated those for PPARγin a concentration- and time-dependent manner (P<0.05). Moreover, EMSA showed that AGE-BSA also inhibited the transcription activity of PPARγin a concentration-dependent manner (P <0.05).
4. Immunocytochemistry showed that AGE-BSA decreased the expression level of proteins for PPARγbut increased that of SR-A significantly (P <0.05).
5. Compared with the control group, the expression of PPARγmRNA increased after PPARγagonist treated but decreased after anti-PPARγmonoclonal antibody treated (P<0.05). Moreover, the expression of ACAT-1 mRNA decreased after PPARγagonist stimulating but increased after anti-PPARγmonoclonal antibody stimulating (P<0.05). The same changes can be observed from Western blot analysis.
6. Macrophages were pretreated with rosiglitazone at different concentrations (1μM, 5μM and 10μM) for 4h before exposed to 200mg/L AGE-BSA. We found that rosiglitazone impaired ACAT-1 expression induced by AGEs in a concentration-dependent manner significantly (P <0.05).
Conclusions:
1. AGE-BSA increased significantly the expression levels of mRNA and proteins for ACAT-1 in a concentration-and time-dependent manner.
2. AGE-BSA not only decreased the expression levels of mRNA and proteins for PPARγ, but also inhibited the transcription activity of PPARγin macrophages in a concentration-dependent manner, significantly.
3. AGE-BSA could promote macrophage intaking lipids by upregulating the expression of SR-A, which contributes to macrophage-derived foam cell formation.
4. The increased expression of PPARγand reduced of ACAT-1 after PPARγligand stimulation suggest that PPARγmay inhibit the expression of ACAT-1.
5. Rosiglitazone, a PPARγspecific agonist, could significantly inhibit the expression levels of mRNA and proteins for ACAT-1 induced by AGEs in a concentration-dependent manner, which suggests that activation of PPARγcould regulate ACAT-1 transcriptionally to prevent cholesterol esters accumulate in macrophage, thereby inhibiting the macrophage-derived foam cell formation induced by AGEs.
引文
1.孙黎明,等.第17届国际糖尿病大会简介.中国糖尿病杂志, 2001, 9: 60-62.
2. Schmidt AM, Yan SD, Wautier JL, et al. Activation of receptor for advanced glycation end products: A mechanism for chronic vascular dysfunction indiabetic vasculopathy and artherosclerosis. Circ Res, 1999, 4: 489-497.
3.钟学礼主编.临床糖尿病学.上海:上海科学技术出版社, 1997, 83-89.
4. Miyata T, van Ypersele de Strihou C, Kurokawa K, et al. Alternations in nonenzymatic biochemistry in uremia: origin and significance of“carbony stress”in long-term uremic complications. Kidney Int, 1999, 55(2): 389-399.
5. Schemidt AM, Hori Osamu, Brett J, et al. Cellular receptor for advanced glycation end products. Aterioscler thromb, 1994, 14: 1521-1528.
6. Jandeleit-Dahm K, Watson A, Soro-Paavonen A. The AGE/RAGE axis in diabetes-accelerated atherosclerosis. Clin Exp Pharmacol Physiol. 2008, 35(3): 329-334.
7. Takahashi K, Takeya M, Sakashita N. Multifunctional roles of macrophages in the development and progression of atherosclerosis in humans and experimental animals. Med Electron Microsc, 2002, 35(4): 179-203.
8. Miyazaki A, Nakayama H, Horiuchi S. Scavenger receptors that recognize advanced glycation end products. Trends Cardiovasc Med, 2002,12(6): 258-262.
9. Horiuchi S, Sakamoto Y, Sakai M. Scavenger receptors for oxidized and glycated proteins.Amino Acids, 2003, 25(3-4): 283-292.
10. Beauchamp MC, Michaud SE, Li L, Sartippour MR, Renier G Advanced glycation end products potentiate the stimulatory effect of glucose on macrophage lipoprotein lipase expression. J Lipid Res, 2004, 45(9): 1749-1757.
11. Watanabe T, Nishio K, et al. Impact of salusin-alpha and -beta on human macrophage foam cell formation and coronary atherosclerosis. Circulation, 2008, 117(5): 638-648.
12. Chang TY, Chang CC, Lin S, et al. Roles of acyl-coenzyme A: cholesterol acyltransferase-1 and 2. Curr Opin lipidol, 2001, 12: 289-296.
13. Buhman KF, Accad M, Farese RV. Mammalian acyl-CoA: cholesterol acyltransferases. Biochim Biophys Acta, 2000, 1529: 142-154.
14. Miyazaki A, Sakashita N, Lee O, et al. Expression of ACAT-1 protein in human atherosclerotic lesions and cultured human monocytes-macrophages. Arterioscler Thromb Vasc Biol, 1998, 18: 1568.
15. Barak Y, Nelson MC, Ong ES, et al. PPARγis required for placental, cardiac, and adipose tissue development. Mol Cell, 1999, 4(4): 585-595.
16. Kubota N, Terauchi Y, Miki H, et al. PPARγmediates high-fat diet-induced adipocyte hypertrophy and insulin resistance. Mol Cell, 1999, 4(4): 597-609.
17. Rosen ED, Sarraf P, Troy AE, et al. PPARγis required for the differentiation of adipose tissue in vivo and in vitro. Mol Cell, 1999, 4:611-617.
18. Desvergne B and Wahli W. Peroxisome proliferator-activated receptors: nuclear control of metabolism. Endocr Rev, 1999, 20: 649-688.
19. Kliewer SA, Xu HE, Lambert MH, and Willson TM. Peroxisome proliferator-activated receptors: from genes to physiology. Recent Prog Horm Res, 2001, 56: 239-263.
20. Lee CH and Evans RM. Peroxisome proliferator-activated receptor-γin macrophage lipid homeostasis. Trends Endocr Metab, 2002, 13(8): 331-335.
21. Nagy L, et al. Oxidized LDL regulates macrophage gene expression through ligand activation of PPARγ. Cell, 1998, 93: 229-240.
22. Nicholson AC, Hajjar DP. CD36, oxidized LDL and PPAR gamma: pathological interactions in macrophages and atherosclerosis. Vascul Pharmacol, 2004, 41(4-5): 139-146.
23. Moore K.J, et al. The role of PPARγin macrophage differentiation and cholesterol uptake. Nat Med, 2001, 7: 41-47.
24. Chinetti G, et al. PPARαand PPARγactivators induce cholesterol removal from human macrophage foam cells through stimulation of the ABCA1 pathway. Nat Med, 2001, 7: 53-58.
25. Chawla A, et al. A PPARγ-LXR-ABCA1 pathway in macrophages is involved in cholesterol efflux and atherogenesis. Mol Cell, 2001, 7: 161-171.
26. Ricote M, Valledor AF, Glass CK. Decoding transcriptional programs regulated by PPARs and LXRs in the macrophage: effects on lipid homeostasis, inflammation, and atherosclerosis. Arterioscler Thromb Vasc Biol, 2004, 24(2): 230-239.
27. Malerod L, Sporstol M, J uvet LK, et al. Hepatic scavenger receptor class B, type I is stimulated by peroxisome proliferators-activated receptor gamma and hepatocyte nuclear factor alpha [J]. Biochem Biophys Res Commun, 2003, 305(3): 557-565.
1. Yamagishi S, Nakamura K, Matsui T, et al. Receptor for advanced glycation end products (RAGE): a novel therapeutic target for diabetic vascular complication. Curr Pharm Des, 2008, 14(5): 487-495.
2. Iwashima Y, Eto M, Horiuchi S, and Sano H. Advanced Glycation End Product-Induced Peroxisome Proliferator-Activated Receptor g Gene Expression in the Cultured Mesangial Cells. Biochem Biophys Res Commun, 1999, 264: 441-448.
3. Iwashima Y, Eto M, Hata A, et al. Advanced Glycation End Products-Induced Gene Expression of Scavenger Receptors in Cultured Human Monocyte-Derived Macrophages [J]. Biochem Biophys Res Commun, 2000, 277: 368-380.
4. Ulrich P and Cerami A. Protein glycation, diabetes, and aging. Recent Prog Horm Res, 2001, 56:1-21.
5. Garay-Sevila ME, Regalado JC, Malacara JM, et a1. Advanced glycosylation endprod ucts in skin, serum, saliva and urine and its association with complications of patients witll type 2 diabetes mellitus. J Endocrinol Invest, 2005, 28: 223-230.
6. Rojas A, Morales MA. Advanced glycation and endothelial functions:a 1ink towards Vascular complications in diabetes. Life Sci, 2004, 76: 715-730.
7. Aronson D, Rayfield EJ. How hyperglycemia promotes atherosclerosis: molecular mechanisms. Cardiovasc Diabetol, 2002, 8:1(1): 1.
8. Jakus V, Rietbrock N. Advanced glycation end-products and the progress of diabetic vascular complications[J ]. Physiol Res, 2004, 53(2): 131-142.
9. Vasdev S, Gill V, Singal P. Role of advanced glycation end products in hypertension and atherosclerosis: therapeutic implications. Cell Biochem Biophys, 2007, 49(1): 48-63.
10. Vlas sara H, Fuh H, Donnely T, et a1. Advanced glycation end products promoteadhesion molecule (VCAM-1, ICAM-1) expression and atheroma formation in normal rabbits. Mol Med, 1995, 1(4):447-456.
11. Forbes JM, Yee LT, I'hallas V, et a1. Advanced glycation end product interventions reduce diabetes accelerated atherosclerosis. Diab etes, 2004, 53: 1813-1823.
12. Price CL, Knight SC. Advanced glycation: a novel outlook on atherosclerosis. Curr Pharm Des, 2007, 13(36): 3681-3687.
13. Linton MF, Fazio S. Class A scavenger receptor, macrophages, and atherosclerosis. Curr Opin Lipidol, 2001, 12: 489-495.
14. Villiers WJ, Smart EJ. Macrophage scavenger receptors and foam cell formation. J Leukoc Biol, 1999, 66: 740-746.
15. Fu Y, Luo L, Luo N, Garvey WT. Lipid metabolism mediated by adipocyte lipid binding protein (ALBP/aP2) gene expression in human THP-1 macrophages. Atherosclerosis, 2006, 188(1): 102-111.
16. Horiuchi S, Sakamoto Y, Sakai M. Scavenger recepters for oxidized and glycated proteins [J]. Amino Acids, 2003, 25(3): 283-292.
17. Beauchamp MC, Michaud SE, Li L, et al. Advanced glycation end products potentiate the stimulatory effect of glucose on macrophage lipoprotein lipase expression [J]. J Lipid Res, 2004, 45(9): 1749-1757.
18. Thomas MC, Baynes JW, Thorpe SRS, et al. The role of AGEs and AGE inhibitors in diabetic cardiovascular disease [J]. Curr Drug Targets, 2005, 6(4): 453-474.
19. Machado AP, Pinto RS, Moyses ZP, et al. Aminoguanidine and metformin prevent the reduced rate of HDL-mediated cell cholesterol efflux induced by formation of advanced glycation end products [J]. Int J Biochem Cell Biol, 2006, 38(3): 392-403.
20. Chang TY, Chang CC, Chen D. Acyl-Coenzyme A: cholesterol acyltransferase [J]. Ann Rev Biochem, 1996, 66: 613-638.
21. Chang TY, Chang CC, Lin S, et al. Roles of acyl-coenzyme A: cholesterol acyltransferase-1 and 2. Curr Opin lipidol, 2001, 12: 289-296.
22. Wang H, Germain SJ, Benfield PP, et al. Gene expression of acyl-coenzyme A: cholesterol acyltransferase is upregulated in human monocytes during differentiation and foam cell formation. Arterioscler Thromb Vasc Biol, 1996, 16: 809-814.
23. Dove DE, Su YR, Zhang W, et al. ACAT1 deficiency disrupts cholesterol efflux andalters cellular morphology in macrophages. Arterioscler Thromb Vasc Biol. 2005, 25(1): 128-134.
24. Yang JB, Duan ZJ, Yao W, et al. Synergistic transcriptional activation of human ACAT-1 gene by IFN-γand TNF-αin THP-1 cells[J]. J. Biol Chem, 2001, 276: 20989-20998.
25. Kruth HS, Huang W, Ishii I, et al. Macrophage foam cell formation with native low density lipoprotein [J]. J Biol Chem, 2002, 277(37): 34573-34580.
26. Cathcart MK. Regulation of superoxide anion production by NAPDH oxidase in monocytes/ macrophages: contributions to atherosclerosis [J]. Arterioscler. Thromb Vasc Biol, 2004, 24(1): 23-28.
27. Ikenoya M, Yoshinaka Y, et al. A selective ACAT-1 inhibitor, K-604, suppresses fatty streak lesions in fat-fed hamsters without affecting plasma cholesterol levels. Atherosclerosis, 2007, 191(2): 290-297.
1. Wahli W, Braissant O, Desvergne B. Peroxisome proliferator activated receptors: transcriptional regulators of adipogenesis, lipid metabolism and more. Chem Biol, 1995, 2(5): 261-266.
2. American Diabetes Association. Implications of the Diabetes Control and Complications Trial. Diabetes Care, 2002, 25: S25-S27.
3. Stratton IM, Adler AI, Neil HA, et al. Association of glycaemia with macrovascular and microvascular complications of type 2 diabetes (UKPDS 35): prospective observational study. BMJ, 2000, 321: 405-412.
4. Yamagishi S, Nakamura K, Imaizumi T. Advanced Glycation End Products (AGEs) and Diabetic Vascular Complications. Curr Diabetes Rev, 2005, 1(1): 93-106.
5. Garay-Sevila ME, Regalado JC, Malacara JM, et a1. Advanced glycosylation end products in skin, serum, saliva and urine and its association with complications of patients with type 2 diabetes mellitus. J Endocrinol Invest, 2005, 28: 223-230.
6. Basta G, Schmidt AM, De-Caterina R. Advanced glycation end products and vascular inflammation: implications for accelerated atherosclerosis in diabetes [J]. Cardiovasc Res, 2004, 63 (4): 582-592.
7. Thomas MC, Baynes JW, Thorpe SRS, et al. The role of AGEs and AGE inhibitors in diabetic cardiovascular disease [J]. Curr Drug Targets, 2005, 6(4): 453-474.
8. Machado AP, Pinto RS, Moyses ZP, et al. Aminoguanidine and metformin prevent the reduced rate of HDL-mediated cell cholesterol efflux induced by formation of advanced glycation end products [J]. Int J Biochem Cell Biol, 2006, 38(3): 392-403.
9. Passarelli M, Tang C, McDonald TO, et al. Advanced glycation end product precursors impair ABCA1-dependent cholesterol removal from cells. Diabetes, 2005, 54(7): 2198-2205.
10. Beauchamp MC, Michaud SE, Li L, Sartippour MR, Renier G. Advanced glycation end products potentiate the stimulatory effect of glucose on macrophage lipoprotein lipase expression. J Lipid Res, 2004, 45(9): 1749-1757.
11. Hsueh WA, Law RE. PPAR gamma and atherosclerosis: effects on cell growth and movement [J]. Arterioscler Thromb Vasc Biol, 2001, 21 (12): 1891-1895.
12. Nagy L, Tontonoz P, Chen J, et al. Oxidized LDL regulates macrophage gene expression through ligand activation of PPARγ. Cell, 1998, 93: 229-240.
13. Lim HJ, Lee S, Lee KS, et al. PPARγactivation induces CD36 expression and stimulates foam cell like changes in rVSMCs. Prostaglandins Lipid Mediators, 2006, 80: 165-174.
14. Li AC, Brown KK, Silvestre MJ, et al. Peroxisome proliferators activated receptor gamma ligands inhibit development of atherosclerosis in LDL receptor-deficient mice [J]. J Clin Invest, 2000, 106 (4): 523-531.
15. Chen Z, Tshibashi S, Perry S, et al. Troglitazone inhibits atherosclerosis in apolipoprotein E-knockout mice: pleiotropic effects on CD36 expression and HDL [J]. Arterioscler Thromb Vasc Biol, 2001, 21(3): 372-377.
16. Koshiyama H, Shimono D, Kuwamura N, et al. Rapid communication: inhibitory effect of pioglitazone on carotid arterial wall thickness in type 2 diabetes [J]. J Clin Endocrinol Metab, 2001, 86 (7): 3452-3456.
17. Chinetti G, et al. PPARαand PPARγactivators induce cholesterol removal from human macrophage foam cells through stimulation of the ABCA1 pathway. Nat Med, 2001, 7: 53-58.
18. Chawla A, et al. A PPARγ–LXR–ABCA1 pathway in macrophages is involved in cholesterol efflux and atherogenesis. Mol Cell, 2001, 7: 161-171.
19. Malerod L, Sporstol M, J uvet LK, et al. Hepatic scavenger receptor class B, type I is stimulated by peroxisome proliferators-activated receptor gamma and hepatocyte nuclear factor alpha [J]. Biochem Biophys Res Commun, 2003, 305 (3) :557-565.
20. Lee CH and Evans RM. Peroxisome proliferator-activated receptor-γin macrophagelipid homeostasis. Trends Endocrinol Metab, 2002, 13(8): 331-335.
21. Plutzky, J. Peroxisome proliferators activated receptors in endothelial cell biology. Curr Opin Lipidol, 2001, 12: 511-518.
22. Yang XY, et al. Activation of human T lymphocytes is inhibited by peroxisome proliferator-activated receptorγ(PPARγ) agonists. PPARγco-association with transcription factor NFAT. J Biol Chem, 2000, 275: 4541-4544.
23. Iwashima Y, Eto M, Hata A, et al. Advanced Glycation End Products-Induced Gene Expression of Scavenger Receptors in Cultured Human Monocyte-Derived Macrophages [J]. Biochem Biophys Res Commun, 2000, 277: 368-380.
24. Argmann CA, Sawyez CG, McNeil CJ, et al. Activation of peroxisome proliferators-activated receptor gamma and retinoid X receptor results in net depletion of cellular cho lesteryl esters in macrophages exposed to oxidized lipoproteins [J]. Arterioscler Thromb Vasc Biol, 2003, 23(3): 475-482.
1. Chang TY, Chang CY and Cheng D. Acyl-coenzyme A: cholesterol acyltransferase. Annu Rev Biochem. 1997,66:613-638.
2.和平,成蓓,王毅,王洪星. PMA促进人单核细胞分化及ACAT-1基因表达.华中科技大学学报, 2005, 34(4): 395-397.
3.和平,成蓓,彭雯,王毅,王洪星.泡沫细胞形成过程中ACAT-1活性改变及其机制研究.中华心血管病杂志, 2004, 32(2): 158-160.
4. Wang HX, Germain SJ, Benfield PP, et al. Gene expression of Acyl-coenzyme A: cholesterol acyltransferase is upregulated in human monocytes during differentiation and foam cell formation. Arterioscler Thromb Vasc Biol, 1996,16: 809-814.
1. Cooper ME, Bonnet F, Oldfield M, Jandeleit-Dahm K. Mechanisms of diabetic vasculopathy: an overview. Am J Hypertension 2001, 14: 475-486.
2. Feener EP, King GL. Vascular dysfunction in diabetes mellitus. Lancet, 1997, 350(Suppl1): SI9-SI13.
3. Chang TY, Chang Catherine CY, Cheng D, et al. Acyl-Coenzyme A: Cholesterol acyltrasferase [J]. Ann Rev Biochem, 1997, 66: 613-625.
4. Kruth HS, Huang W, Ishii I, et al. Macrophage foam cell formation with native low density lipoprotein. J Biol Chem, 2002, 277: 34573-34580.
5. Cathcart MK. Regulation of superoxide anion production by NAPDH oxidase in monocytes/macrophages: contributions to atherosclerosis. Arterioscler. Thromb Vasc Biol, 2004, 24: 23.
6. Glass CK, Rosenfeld MG. The coregulator exchange in transcriptional functions of nuclear receptors. Genes Dev, 2000, 14: 121-141.
7. Camp HS, Li O, Wise SC, et al. Differential activation of peroxisome proliferator- activated receptor-gamma by troglitazone and rosiglitazone. Diabetes, 2000, 49: 539-547.
8. van Wijk JP, Rabelink TJ. Impact of thiazolidinedione therapy on atherogenesis [J]. Curr Atheroscler Rep, 2005, 7(5): 369-374.
9. Yano Miyuki, Matsumura Takeshi, Senokuchi Takafumi, et al. Troglitazone inhibits oxidized low density lipoprotein-induced macrophage proliferation: Impact of the suppression of nuclear translocation of ERK1/2 [J]. Atherosclerosis, 2007, 191(1): 22-32.
10. Viberti GC. Rosiglitazone: potential beneficial impact on cardiovascular disease [J]. Int J Clin Pract, 2003, 57(2): 128-134.
11. Bakris G, Viberti G, Weston WM, et al. Rosiglitazone reduces urinary albumin excretion in type II diabetes [J]. J Hum Hypertens, 2003, 17(1): 7-12.
12.赵全明,颜东,宋爱丽,等.罗格列酮对ApoE基因敲除小鼠动脉粥样硬化的影响[J].中华心血管病杂志, 2005, 33(5):399.
13.白智峰,成蓓,李长运等. PPARγ对单核/巨噬细胞酰基辅酶A:胆固醇酰基转移酶-1表达效应的研究.中国老年学杂志, 2004, 8(24): 717-720.
14. Andrew CL, Christoph JB, Alejan dra G, et al. Differential inhibition of macrophage foam-cell formation and atherosclerosis in mice by PPARα,β/δ, andγ. J. clin Inves. 2004, 114(11): 1564-1576.
15. Nissen SE, Tuzcu EM, Brewer HB, et al. Effect of ACAT inhibition on the progression of coronary atherosclerosis. New Engl J Med, 2006, 354(12): 1253-1263.
1. Eckel RH, Grundy SM, and Zimmet PZ. The metabolic syndrome. Lancet 2005, 365: 1415-1428.
2. Fajas L, Auboeuf D, Raspe E, et al. The organization, promoter analysis, and expression of the human PPAR gamma gene [J]. J Biol Chem, 1997, 272: 18779-18789.
3. Ren D, Collingwood TN, Rebar EJ, et al. PPARγknowdown by engineered transcription factors: exogenous PPARγ2 but not PPARγ1 reactivates adipogenesis [J]. Genes Dev, 2002, 98: 5306-5311.
4. Chawla A, Repa JJ, Evans RM, and Mangelsdorf DJ. Nuclear receptors and lipid physiology: opening the X-files. Science, 2001, 294:1866-1870.
5. Glass CK, Rosenfeld MG. The coregulator exchange in transcriptional functions of nuclear receptors. Genes Dev, 2000, 14: 121-141.
6. McKenna NJ, and O’Malley BW. Combinatorial control of gene expression by nuclear receptors and coregulators. Cell, 2002, 108: 465-474.
7. Desvergne B, and Wahli W. Peroxisome proliferator-activated receptors: nuclear control of metabolism. Endocr Rev, 1999, 20: 649-688.
8. Nagy L, Tontonoz P, Alvarez JG, Chen H, and Evans RM. Oxidized LDL regulates macrophage gene expression through ligand activation of PPARgamma. Cell, 1998, 93: 229-240.
9. McIntyre TM, Pontsler AV, Silva AR, et al. Identification of an intracellular receptor for lysophosphatidic acid (LPA): LPA is a transcellular PPARgamma agonist. Proc. Natl. Acad. Sci USA, 2003, 100: 131-136.
10. Schopfer FJ, Lin Y, Baker PR, Cui T, et al. Nitrolinoleic acid: an endogenous peroxisome proliferator-activated receptor gamma ligand. Proc. Natl Acad Sci USA, 2005, 102: 2340-2345.
11. Bell-Parikh LC, Ide T, Lawson JA, et al. Biosynthesis of 15-deoxy-delta12,14-PGJ2 and the ligation of PPARgamma. J Clin Invest, 2003, 112: 945-955.
12. Straus DS, Pascual G, Li M, et al. 15-deoxydelta 12,14-prostaglandin J2 inhibits multiple steps in the NF-kappa B signaling pathway. Proc. Natl. Acad. Sci. USA, 2000, 97: 4844-4849.
13. Chawla A, Schwarz EJ, Dimaculangan DD, and Lazar, MA. Peroxisome proliferator-activated receptor (PPAR) gamma: adipose-predominant expression and induction early in adipocyte differentiation. Endocrinology, 1994, 135: 798-800.
14. Tontonoz P, Hu E, Graves RA, Budavari AI, and Spiegelman BM. PPAR gamma 2: tissue-specific regulator of an adipocyte enhancer. Genes Dev, 1994, 8: 1224-1234.
15. Barak Y, Nelson MC, Ong ES, Jones YZ, Ruiz-Lozano P, Chien KR, Koder A, and Evans RM. PPAR gamma is required for placental, cardiac, and adipose tissue development. Mol Cell, 1999, 4: 585-595.
16. Rosen ED, Sarraf P, Troy AE, Bradwin G, Moore K, Milstone DS, Spiegelman BM, and Mortensen RM. PPAR gamma is required for the differentiation of adipose tissue in vivo and in vitro. Mol Cell, 1999, 4: 611-617.
17. Lapsys NM, Kriketos AD , Lim-Fraser M, et al. Expression of genes involved in lipid metabolism correlate with peroxisome proliferators-activated receptor gamma expression in human skeletal muscle [J]. J Clin Endocrinol Metab, 2000, 85: 4293-4297.
18. Chui PC, Guan HP, Lehrke M, and Lazar MA. PPARgamma regulates adipocyte cholesterol metabolism via oxidized LDL receptor 1. J Clin Invest, 2005, 115: 2244-2256.
19. Guan HP, Li Y, Jensen MV, Newgard CB, Steppan CM, and Lazar MA. A futile metabolic cycle activated in adipocytes by antidiabetic agents. Nat Med, 2002, 8: 1122-1128.
20. Yamauchi T, Kamon J, Waki H, et al. The mechanisms by which both heterozygous peroxisome proliferator-activated receptor gamma (PPARgamma) deficiency and PPARgamma agonist improve insulin resistance. J Biol Chem, 2001, 276(44): 41245-41254.
21. Boden G, Shulman GI. Free fatty acids in obesity and type 2 diabetes: defining their role in the development of insulin resistance and beta-cell dysfunction.Eur J Clin Invest, 2002, 32(Suppl3): 14-23.
22. Zimmermann R, Haemmerle G, Wagner EM, et al. Decreased fatty acid esterification compensates for the reduced lipolytic activity in hormone-sensitive lipase-deficient white adipose tissue.J Lipid Res, 2003, 44(11): 2089-2099.
23. Wang ZW, Pan WT, Lee Y, et al. The role of leptin resistance in the lipid abnormalities of aging. FASEB J, 2001, 15(1): 108-114.
24. Tontonoz P, Nagy L, Alvarez JGA, et al. PPARγpromotes monocyte/macrophage differentiation and uptake of oxidized LDL [J]. Cell, 1998, 93: 241-252.
25. Nagy L, Tontonoz P, Alvarez JG., et al. Oxidized LDL regulates macrophage gene expression through ligand activation of PPAR gamma. Cell, 1998, 93: 229-240.
26. Argmann CA, Sawyez CG, McNeil CJ, et al. Activation of peroxisome proliferators-activated receptor gamma and retinoid X receptor results in net depletion of cellular cholesteryl esters in macrophages exposed to oxidized lipoproteins [J]. Arterioscler Thromb Vasc Biol, 2003, 23(3): 475-482.
27. Jackson SM, Parhawi F, Xi XP, et al. Peroxisome proliferators activated receptor activators target human endothelial cells to inhibit leukocyte-endothelial cell interaction [J]. Arterioscler Thromb Vasc Biol, 1999, 19(9): 2094-2104.
28. Li L, Beauchamp MC, Renier G. Peroxisome proliferators-activated receptor alpha and gamma agonists upregulate human macrophage lipoprotein lipase expression [J]. Atherosclerosis, 2002, 165(1): 101-110.
29. Chawla A, Boisvert WA, Lee CH, et al. PPAR gamma-LXR-ABCA1 pathway in macrophages is involved in cholesterol efflux and atherogenesis [J]. Mol Cell, 2001, 7(1): 161-171.
30. Chen Z, Tshibashi S, Perry S, et al. Troglitazone inhibits atherosclerosis in apolipoprotein E-knockout mice: pleiotropic effects on CD36 expression and HDL [J]. Arterioscler Thromb Vasc Biol, 2001, 21(3) : 372-377.
31. Li AC, Brown KK, Silvestre MJ, et al. Peroxisome proliferators activated receptor gamma ligands inhibit development of atherosclerosis in LDL receptor-deficient mice [J]. J Clin Invest, 2000, 106(4):523-531.
32. Koshiyama H, Shimono D, Kuwamura N, et al. Rapid communication: inhibitory effect of pioglitazone on carotid arterial wall thickness in type 2 diabetes [J]. J Clin Endocrinol Metab, 2001, 86(7):3452-3456.
33. May J. Troglitazone, but not rosiglitazone, inhibits Na+/H+ exchange activity and proliferation of macrovascular endothelial cells [J]. J Diabetes Compl, 2001, 15:120-127.
34. Sugawara A, Uruno A, Kudo M, et al. Transcription suppression of thromboxane receptor gene by peroxisome proliferators-activated receptor gamma via an interaction with Sp1 in vascular smooth muscle cells [J]. J Biol Chem, 2002, 22(12): 9676-9683.
35. Li M, Pascual G and Glass CK. Peroxisome proliferators activated receptor gamma-dependent repression of the inducible nitricoxide synthase gene. Mol Cell Biol, 2000, 20: 4699-4707.
36. Jiang C, Ting AT, Seed B. PPARγagonists inhibit production of monocyte inflammatory cytokines [J]. Nature,1998, 391: 82-86.
37. Wang AC, Dai X, Luu B, et al. Peroxisome proliferators-activated receptor gamma regulates airway epithelial cell activation [J]. AmJ Respir Cell Mol Biol, 2001, 24: 688-693.
38. Su CG, Wen X, Bailey ST, et al. A novel therapy for colitis utilizing PPAR-gamma ligands to inhibit the epithelial inflammatory response [J]. J Clin Invest, 1999, 104: 383-389.
39. Grommes C, Landreth GE, and Heneka MT. Antineoplastic effects of peroxisome proliferator-activated receptor gamma agonists. Lancet Oncol, 2004, 5: 419-429.
40. Mueller E, Smith M, Sarraf P, et al. Effects of ligand activation of peroxisome proliferators-activated receptor gamma in human prostate cancer [J]. Proc Nat Acad Sci USA,2000, 97:10990-10995.
41. Lefebvre AM, Chen I, Desreumaux P, Najib J, Fruchart JC, et al. Activation of the peroxisome proliferator-activated receptor gamma promotes the development of colon tumors in C57BL/6J-APCMin/+ mice. Nat Med, 1998, 4: 1053-1057.
1. Jakus V, Rietbrock N. Advanced glycation end-products and the progress of diabetic vascular complications. Physiol Res 2004; 53(2): 131-142.
2. Watanabe T, Nishio K, Kanome T, et al. Impact of salusin-alpha and -beta on human macrophage foam cell formation and coronary atherosclerosis. Circulation 2008; 117(5): 638-648.
3. Libby P. Inflammation in atherosclerosis. Nature 2002; 420: 868-874.
4. Desvergne B, Wahli W. Peroxisome proliferator-activated receptors: Nuclear control of metabolism. Endocr Rev 1999; 20: 649-688.
5. Tontonoz P, Nagy L, Alvarez J G, et al. PPARγpromotes monocyte/macrophage differentiation and uptake of oxidized LDL. Cell 1998; 93: 241-252.
6. Chinetti G, Lestavel S, Bocher V, et al. PPARαand PPARγactivators induce cholesterol removal from human macrophage foam cells through stimulation of the ABCA1 pathway. Nature Med 2001; 7: 53-58.
7. Oram J F, Vaughan A M. ABCA1-mediated transport of cellular cholesterol and phospholipids to HDL apolipoproteins. Curr Opin Lipidol 2000; 11:253-260.
8. Rosen E D, Spiegelman B M. Peroxisome Proliferator-Activated Receptor-γligands and atherosclerosis: ending the heartache. J Clin Invest 2000; 106: 629-631.
9. Valerie F, Ko Willems van Dijk, Albert K G, et al. Macrophage-specific inhibition ofNF-κB activation reduces foam-cell formation. Atherosclerosis 2007; 192: 283-290.
10. Chang T Y, Chang C Y and Cheng D. Acyl-coenzyme A: cholesterol acyltransferase. Annu Rev Biochem 1997; 66: 613-638.
11. Wang H, Germain S J, Benfield P P, et al. Gene expression of acyl-coenzyme A: cholesterol acyltransferase is upregulated in human monocytes during differentiation and foam cell formation. Arterioscler Thromb Vasc Biol 1996; 16: 809-814.
12. Dove D E, Su Y R, Zhang W, et al. ACAT1 deficiency disrupts cholesterol efflux and alters cellular morphology in macrophages. Arterioscler Thromb Vasc Biol 2005; 25(1): 128-134.
13. Iwashima Y, Eto M, Horiuchi S, Sano H. Advanced glycation end product-induced peroxisome proliferator-activated receptor gamma gene expression in the cultured mesangial cells. Biochem Biophys Res Commun 1999; 264: 441-448.
14. Via D P, Pons L, Dennison D K, et al. Induction of acetyl-LDL receptor activity by phorbol ester in human monocyte cell line THP-1. J. Lipid Res 1989; 30: 1515-1524.
15. Cooper M E, Bonnet F, Oldfield M, Jandeleit-Dahm K. Mechanisms of diabetic vasculopathy: an overview. Am J Hypertension 2001; 14: 475-486.
16. Feener E P, King G L. Vascular dysfunction in diabetes mellitus. Lancet 2000;350 (Suppl1): S19-S113.
17. Cases S, Nevak S, Zhang Y W, et al. ACAT-2, a second mammalian acyl-coenzyme A : Cholesterol acyltrasferase. Biol Chem 1998; 273: 26755-26764.
18. Hashimoto S, Dayton S. Studies of the mechanism of augmented synthesis of cholesteryl ester in atherosclerotic rabbit aortic microsomes. Atherosclerosis l977; 28: 447-452.
19. Bocan T M, Mueller S B, Uhlendorf P D, et al. Comparison of CI-976, an ACAT inhibitor, and selected 1ipid-lowering agents for antiatherosclerotic activity in iliac-femoral and thoracic aortic lesions. A biochemica1, morphological, and morphometric evaluation. Arterioscler Thromb 1991; 11: l830-1843.
20. Wang H X, Germain S J, Benfield P P, et al. Gene expression of Acyl-coenzyme A: cholesterol acyltransferase is upregulated in human monocytes during differentiation and foam cell formation. Arterioscler Thromb Vasc Biol 1996; 16: 809-814.
21. Kruth H S, Huang W, Ishii I, et al. Macrophage foam cell formation with native lowdensity lipoprotein. J Biol Chem 2002; 277: 34573-34580.
22. Cathcart M K. Regulation of superoxide anion production by NAPDH oxidase in monocytes/macrophages: contributions to atherosclerosis. Arterioscler. Thromb Vasc Biol 2004; 24: 23.
23. Yu C, Chen J, Lin S, et a1. Human acyl-CoA: cholesterol acyl-transferase-1 is a homotetrameric enzyme in intact cells and in vitro. J Biol Chem l999; 274: 36l39-36145
24. Yang L, Yang J B, Chen J, et al. Enhancement of human ACAT-1 gene expression to promote the macrophage-derived foam cell formation by dexamethasone. Cell Research 2004; 14(4): 315-323
25. Panousis C G, Zuckerman S H. Regulation of cholesterol distribution in macrophage-derived foam cells by interferon-gamma. J Lipid Res 2000; 41: 75-83
26. Yang J B, Duan Z J, Yao W, et a1. Synergistic transcriptional activation of human ACAT-l gene by IFN-gamma and ATRA in THP-l cells. J Biol Chem 200l; 276: 20989-20998
27. He P, Cheng B, WANG Y, et al. Effects of Tumor Necrosis Factor-аon ACAT activity and ACAT-1 gene expression in THP-1 macrophages. J Huazhong University of science and Technology 2007; 27(2): 170-172
28. Wellen K E, and Hotamisligil G S. Obesity-induced inflammatory changes in adipose tissue. J. Clin Invest 2003; 112: 1785-1788.
29. Glass C K, Witztum J L. Atherosclerosis: The Road Ahead. Cell 200l; 104: 503-5l6.
30. Bai Z F, Cheng B, Li C Y, et al. Effects of ligand-activation of peroxisome proliferator activated receptors (PPAR) on expression of ACAT-1 in cultured human monocytes-macrophages. Chinese J Gerontology 2004; 8(24): 717-720.
31. Andrew C L, Christoph J B, Alejan dra G, et al. Differential inhibition of macrophage foam-cell formation and atherosclerosis in mice by PPARα,β/δ, andγ. J. clin Inves 2004; 114(11): 1564-1576.