孕激素对人成骨样细胞膜型基质金属蛋白酶-1表达和明胶酶-A激活的影响

目的研究孕激素对人成骨样细胞MG-63膜型基质金属蛋白酶(MT1-MMP)表达和明胶酶-A激活的影响,探讨孕激素治疗绝经后骨质疏松症(OP)的作用机制.方法MG-63细胞用孕酮干预;半定量逆转录聚合酶链反应、Western杂交和激光共聚焦显微系统免疫荧光法分别检测MT1-MMPmRNA和蛋白质表达;明胶酶-A激活用明胶酶谱和酶联免疫吸附(ELISA)检测.结果观察到孕酮增强MG-63细胞MT1-MMPmRNA表达呈剂量依赖性,其中10-9mol/L孕酮组为对照组的(127±11)%(P＜0.01),10-8mol/L孕酮组为对照组的(171±19)%(P＜0.001).孕酮增强MG-63细胞MT1-MMP蛋白质表达呈剂量依赖关系,其中10-9mol/L孕酮组为对照组的(188±85)%(P＜0.001),10-8mol/L孕酮组为对照组的(233±25)%(P＜0.0001).激光共聚焦显微系统免疫荧光法证实孕酮促进MT1-MMP蛋白质表达增强,MT1-MMP蛋白质表达于细胞膜和细胞质中.孕酮对明胶酶-A激活无影响(P＞0.05),即孕酮诱导的MG-63细胞MT1-MMP表达增强不能增强明胶酶-A的激活.结论MT1-MMP在骨重建过程中起着维持骨形成的关键作用,孕激素可通过诱导人成骨样细胞MT1-MMP表达增强促进骨形成.

The regulation of the expression of membrane type-1 matrix metalloproteinase and gelatinase-A activation by progesterone in human osteoblast-like cells cultures

Objective To characterize the effects of progesterone(P) on the expression of membrane type 1 matrix metalloproteinase (MT1 MMP) and gelatinase A activation in human osteoblast like cell strain MG 63 in order to understand the mechanism of progestin acting on the bone. Methods Semi quantitative RT PCR, Western blot, and confocal immunohistochemistry were used to study the actions of P on the expression of mRNA and protein of the MT1 MMP in cultured MG 63 cells. Zymogram of the gelatin and ELISA were performed to examine the effects of P on the activation of gelatinase A. Results Treatment with increasing dose of P in MG 63 cells caused a dose dependent increase in the expression of MT1 MMP mRNA ( P <0 05) and protein ( P <0 05) , and this was furthermore confirmed by confocal immunohistochemistry. It seemed that P showed no influence on the activation of gelatinase A in MG 63 cells culture ( P >0 05). Conclusions Our studies suggested that P might promote the bone formation by increasing MT1 MMP production in osteoblastic cells and thus played an important role in maintaining the osteogenic activity of osteoblasts and preparing the bone matrix for the subsequent bone cell migration and the deposition of new matrix.