Effect of Endothelin-1 on the Expression of Monocyte Chemoattractant Protein-1 in Cultured Human Proximal Tubular Epithelial Cells / 대한신장학회잡지

ABSTRACT

BACKGROUND: Monocyte chemoattractant protein- 1 (MCP-1) is produced by renal cells and an important mediator for monocyte/macrophage infiltration in various inflammatory renal diseases. In the process of renal disease, endothelin-1 is known to play an active role in cell growth, inflammation and fibrosis. The aim of this study was to investigate whether endothelin-1 regulates MCP-1 expression in cultured human proximal tubular epithelial cells. METHODS: Primary cultured human proximal tubular epithelial cells (PTEC) were incubated with or without various dose of endothelin-1. MCP-1 concentration in PTEC conditioned medium was measured by sandwich ELISA. MCP-1 mRNA expression was analyzed by Northern blotting. The NF-kB or AP-1 activity in response to endothelin-1 was measured by electrophoretic mobility shift assay. RESULTS: Endothelin-1 (10(-7) M) stimulated MCP- 1 production in PTEC, which was significant at 48 hours and various doses of endothelin-1 (10(-8)-10(-6) M) increased MCP-1 production from PTEC in a dose-dependent manner. Northern blot analysis revealed that endothelin-1 stimulated MCP-1 mRNA expression. Endothelin-1 (10(-7) M) stimulated both AP-1 binding activity and NF-kB binding activity up to 8 hour. Supershift analysis showed that p65 and p50 are major NF-kB subunit bound to the DNA probe and that c-Fos and c-Jun are major AP-1 subunit bound to the DNA probe. CONCLUSION: Our results suggest that endothelin- 1 may stimulate MCP-1 expression in proximal tubular epithelial cells through the activation of NF- kB and AP-1 binding activity.