Expression of connective tissue growth factor induced by parathyroid hormone via MAPK signaling pathway in human renal proximal tubular cells / 中华肾脏病杂志

ABSTRACT

Objective To evaluate the effect of parathyroid hormone (PTH) on the expression of connective tissue growth factor (CTGF) in human renal tubular epithelial cells, and to explore the role of MAPK signaling pathway. Methods Real time RT-PCR, Western blot, and reporter gene assay were employed to detect PTH-induced CTGF expression in HK-2 cells. Inhibitors (PD98059 and U0126) of MAPK signaling pathway were used to confirm involved signal pathway. Results HK-2 cells had basic expression level of CTGF mRNA and protein, which were increased significantly after treatment with PTH. The luciferase activity was up-regulated to a higher level as compared with control group after treatment with 10-10 mol/L PTH for 12 h [(1.8884±0.0780) vs (0.9891±0.0300) A, P<0.01]. Moreover, a small amount of p-ERK1/2 was detected in normal HK-2 cells, but it was increased significantly in response to PTH activation, most remarkably when treated with 10-10 mol/L PTH for 30 min. Inhibitors of MAPK signaling pathway, PD98059 and U0126, noticeably inhibited the expression of CTGF mRNA and protein as well as gene promoters in HK-2 cells. Conclusion PTH can induce higher expression of CTGF in HK-2 cells probably via MAPK signaling pathway.