甲状旁腺素对人肾小管上皮细胞细胞外基质合成与降解的影响

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.

Effects of parathyroid hormone on synthesis and degradation of extracellular matrix in cultured human renal tubular epithelial cells