Pioglitazone inhibits connective tissue growth factor expression in advanced atherosclerotic plaques in low-density lipoprotein receptor-deficient mice.
Connective tissue growth factor (CTGF) is expressed in atherosclerotic plaques. It is generally recognized that CTGF contributes to atherosclerosis by stimulating vascular smooth muscle cell (VSMC) proliferation and extracellular matrix production during the development of atherosclerosis. Recent studies indicate that CTGF may also contribute to plaque destabilization as it induces apoptosis and stimulates MMP-2 expression in VSMCs. Thiazolidinediones (TZDs), a new class of insulin sensitizing drugs for type 2 diabetes, inhibit atherosclerosis. However, their effect on CTGF expression in atherosclerotic plaques remains unknown. In this study, male LDL receptor-deficient mice were fed high-fat diet for 4 months to induce the formation of atherosclerotic plaques and then given the high-fat diet with or without pioglitazone for the next 3 months. At the end of the 7-month study, CTGF expression in aortic atherosclerotic lesions was examined. Results showed that CTGF expression was increased in mice fed the high-fat diet by seven-fold as compared to that in mice fed normal chow, but the treatment with pioglitazone significantly inhibited the high-fat diet-induced CTGF expression. To verify these in vivo observations, in vitro studies using human aortic SMC were conducted. Quantitative real-time PCR and Western blot showed that pioglitazone inhibited TGF-beta-stimulated CTGF expression. In conclusion, the present study has demonstrated that pioglitazone inhibits CTGF expression in mouse advanced atherosclerotic plaques and in cultured human SMCs, and hence unveiled a possible mechanism potentially involved in the inhibition of atherosclerosis by TZD.
Game
Bryan A
BA
Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403, United States.
He
Lin
L
Jarido
Veronica
V
Nareika
Alena
A
Jaffa
Ayad A
AA
Lopes-Virella
Maria F
MF
Huang
Yan
Y
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D050197:Atherosclerosis / Q000188:drug therapy*; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor; D004036:Diet, Atherogenic; D004195:Disease Models, Animal; D015536:Down-Regulation; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D017874:Immediate-Early Proteins / Q000187:drug effects* / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000187:drug effects; D000077205:Pioglitazone; D011973:Receptors, LDL / Q000235:genetics; D045162:Thiazolidinediones / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000187:drug effects
C526317:CCN2 protein, human; C526318:CCN2 protein, mouse; D007004:Hypoglycemic Agents; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D011973:Receptors, LDL; D045162:Thiazolidinediones; D016212:Transforming Growth Factor beta; D055513:Connective Tissue Growth Factor; D000077205:Pioglitazone