Effects of parathyroid hormone on synthesis and degradation of extracellular matrix in cultured human renal tubular epithelial cells / 中华肾脏病杂志

ABSTRACT

Objective To investigate the effects of parathyroid hormone (PTH) on the synthesis and secretion of collagen Ⅲ and fibronectin (FN), and the expressions of plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) mRNA in cultured human renal tubular epithelial cells (HK-2).Methods HK-2 cells were cultured in DMEM-F12 medium supplemented with 5% FBS. Cells were exposed to different concentrations of PTH (0, 10-12, 10-11, 10-10, 10-9, 10-8 mol/L) for 48 h, or 10-8 mol/L PTH at different time (0, 12, 24, 48, 72 h). The gene expressions of collagen Ⅲ,FN, PAI-1, MMP-1, and TIMP-1 were detected by semi-quantitative RT-PCR. The protein expression of collagen Ⅲ was detected by Western blotting. The level of FN in the supernatant was assayed by enzyme linked immunosorbent assay (ELISA). Results PTH increased gene expressions of collagen Ⅲ, FN, PAI-1 and TIMP-1 in a dose- and time-dependent manner, but decreased MMP-1 gene expression. Then the ratio of MMP-1/TIMP-1 was decreased. PTH increased the collagen Ⅲ protein expression in cultured HK-2 cells and the level of FN in the supernatant of cultured HK-2 cells in a dose- and time-dependent manner. Conclusion PTH can up-regulate PAI-1, TIMP-1 gene expressions, and down-regulate MMP-1 gene expression,resulting in elevation of extracellular matrix (ECM) synthesis and reductim of degradation.