雌二醇对人成骨样细胞基质金属蛋白酶及其抑制因子的作用

The effects of 17 β-estradiol on the expression of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases in human osteoblast-like cells

目的 探讨雌二醇 (E2 )对人成骨样MG 6 3细胞基质金属蛋白酶 (MMP)及基质金属蛋白酶抑制因子 (TIMP)的作用和雌激素缺乏致骨质疏松 (OP)的发病机制。方法 MMP和TIMP用酶联免疫吸附法和免疫印迹法检测 ,mRNA用逆转录聚合酶链反应检测。MMP活性用明胶酶谱法检测。结果 人成骨样MG 6 3细胞在 2 4d的培养中表达MMP 1、MMP 2、TIMP 1和TIMP 2 ,但不表达MMP 3、MMP 8和MMP 9。首次发现E2 抑制MMP 1mRNA和蛋白质表达 ,并呈剂量依赖关系 ;E2 抑制MMP 2活性、增加TIMP 2分泌 ,但不影响MMP 2酶原含量 ,对TIMP 1mRNA及蛋白质表达亦无影响。结论 雌激素不足可通过减弱其对人成骨样细胞MMP 1、MMP 2的抑制作用及对TIMP 2的诱导增强作用 ,促进骨吸收和骨基质分解 ,此可能为雌激素缺乏致OP的重要发病机制。

Objective To characterize the effects of 17 β estradiol(E 2) on the expression of matrix metalloproteinases (MMP) and tissue inhibitors of matrix metalloproteinases (TIMP) in human MG 63 osteoblast like cell line in order to understand the mechanism of estrogen deficient osteoporosis(OP) Methods The expression and activity of MMP and TIMP mRNA and protein under conditions of MG 63 cells with and without treatment of E 2 were measured by reverse transcriptase PCR,ELISA and Western blot, gelatin zymogram respectively Results MMP 1,MMP 2,TIMP 1,TIMP 2 mRNA were expressed during the 24 days of MG 63 cell culture,but not for MMP 3,MMP 8,MMP 9 Treatment with increasing dose of E 2 in MG 63 cells caused a dose dependent decrease in the expression of MMP 1 protein and mRNA E 2 seemed to have no influence on the expression of TIMP 1 mRNA and protein and the levels of proMMP 2,but it did have an effect to inhibit the activity of MMP 2 as well as a positive effect on the levels of TIMP 2 Conclusion Deficiency of E 2 as seen in postmenopausal women might decrease the inhibiting effect on MMP 1 and MMP 2 and reduce the expression of TIMP 2 in human osteoblast,which could lead to increased degradation of bone matrix and bone resorption followed by acceleration of bone loss It is probably the key pathogenesis of estrogen deficient OP