Submitted on November 19, 2007
Accepted on June 12, 2008
MCP-1/CCR2 System is Involved in High Glucose-Induced Fibronectin and Type IV Collagen Expression in Cultured Mesangial Cells
Jehyun Park1, Dong-Ryeol Ryu2, Jin-Ji Li3, Dong-Sub Jung1, Seung-Jae Kwak1, Sun Ha Lee1, Tae-Hyun Yoo1, Seung Hyeok Han1, Jung Eun Lee1, Dong Ki Kim1, Sung Jin Moon1, Kunhong Kim4, Dae Suk Han1, and Shin-Wook Kang1*
1 Department of Internal Medicine, College of Medicine, Brain Korea 21, Yonsei University, Seoul, Korea, Republic of
2 Department of Internal Medicine, College of Medicine, Ewha Womans University, Seoul, Korea, Republic of
3 Department of Internal Medicine, College of Medicine, Brain Korea 21, Yonsei University, Seoul, Korea, Republic of; Nephrology and Dialysis Unit, Department of Internal Medicine, The Affiliated Hospital, YanBian University Medical College, JiLin, China
4 Department of Biochemistry and Molecular Biology, College of Medicine, Brain Korea 21, Yonsei University, Seoul, Korea, Republic of
* To whom correspondence should be addressed. E-mail: kswkidney{at}yumc.yonsei.ac.kr.
Monocyte chemoattractant protein-1(MCP-1) is a potent chemokine that plays an important role in the recruitment of macrophages. Although previous studies have demonstrated the importance of MCP-1 in the pathogenesis of diabetic nephropathy(DN) in terms of inflammation, the role of MCP-1 and its receptor(C-C chemokine receptor 2; CCR2) on extracellular matrix(ECM) accumulation under diabetic conditions has been largely unexplored. This study was undertaken to investigate the functional role of the MCP-1/CCR2 system on high glucose-induced ECM(fibronectin and type IV collagen) protein expression in cultured mesangial cells(MCs). Mouse MCs were exposed to medium containing 5.6mM glucose(NG), NG+24.4mM mannitol(NG+M), or 30mM glucose(HG) with or without mutant MCP-1(mMCP-1), CCR2 siRNA, or CCR2 inhibitor(RS102895). To examine the relationship between MCP-1 and TGF-
1, MCs were also treated with TGF-1(2ng/ml) with or without mMCP-1 or CCR2 siRNA. Transient transfection was performed with Lipofectamine 2000 for 24 hours. Cell viability was determined by an MTT assay, mouse and human MCP-1 and TGF-1 levels by ELISA, and CCR2 and ECM protein expression by Western blot. Transfections of mMCP-1 and CCR2 siRNA increased human MCP-1 levels and inhibited CCR2 expression, respectively. HG-induced ECM protein expression and TGF-1 levels were significantly attenuated by mMCP-1, CCR2 siRNA, and RS102895(p<0.05). MCP-1 directly increased ECM protein expression and this increase was inhibited by an anti-TGF-1 antibody. In addition, TGF-1-induced ECM protein expression was significantly abrogated by the inhibition of the MCP-1/CCR2 system(p<0.05). These results suggest that an interaction between the MCP-1/CCR2 system and TGF-1 may contribute to ECM accumulation in DN.
