Rho-kinase mediates TNF-α-induced MCP-1 expression via p38 MAPK signaling pathway in mesangial cells.
Macrophage accumulation has been implicated in the pathogenesis of inflammatory glomerular disease. Monocyte chemoattractant protein-1 (MCP-1) plays a central role in recruiting monocytes to the glomeruli. Tumor necrosis factor-α (TNF-α) has been shown to induce MCP-1 expression in mesangial cells, although the precise mechanisms remain unclear. We previously demonstrated that RhoA and its effector, Rho-kinase (Rho-associated coiled-coil containing protein kinase, ROCK), are involved in the pathogenesis of diabetic nephropathy. However, its role in MCP-1 induction by TNF-α has not been elucidated. In the present study, we investigated whether the Rho/Rho-kinase signaling pathway regulates the TNF-α-mediated induction of MCP-1 in mesangial cells. Exposure of mouse mesangial cells (MES-13) to TNF-α resulted in an increase of MCP-1 expression (by RT-PCR) and secretion into the medium (by ELISA). Pull down and Western blot analysis revealed that TNF-α activated RhoA and Rho-kinase. Based on these observations, we speculated that the Rho/Rho-kinase signaling pathway may be involved in MCP-1 induction by TNF-α. In agreement with this concept, Y-27632, a specific Rho-kinase inhibitor, attenuated TNF-α-mediated induction of MCP-1. We demonstrated that Y-27632 inhibited TNF-α-mediated monocyte migration and attenuated TNF-α-mediated p38 MAPK activation. Based on these data we infer that Y-27632 inhibits TNF-α-induced MCP-1 expression, secretion and function through inhibition of Rho-kinase and p38 MAPK activity. Our study suggests that Rho/Rho-kinase is an important therapeutic target of monocyte recruitment and accumulation within the glomerulus in inflammatory renal disease.
Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.
Keiichiro
K
Matoba
Daiji
D
Kawanami
Sho
S
Ishizawa
Yasushi
Y
Kanazawa
Tamotsu
T
Yokota
Kazunori
K
Utsunomiya
D000577:Amides / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D018932:Chemokine CCL2 / Q000378:metabolism*; D002633:Chemotaxis; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005921:Glomerulonephritis / Q000378:metabolism; D050527:Mesangial Cells / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D000577:Amides; D018932:Chemokine CCL2; D004791:Enzyme Inhibitors; D011725:Pyridines; D014409:Tumor Necrosis Factor-alpha; C108830:Y 27632; D054460:rho-Associated Kinases; D048051:p38 Mitogen-Activated Protein Kinases