组织金属蛋白酶抑制因子3重组蛋白诱导小鼠成骨细胞MC3T3-E1凋亡

目的 研究组织金属蛋白酶抑制因子3（TIMP-3）重组蛋白对MC3T3-E1成骨细胞凋亡的影响。方法 细胞存活率和凋亡分别用MTT及ELISA检测。Fas，FasL，Bcl-2，Bax，caspase-3，caspase-8，细胞色素c的表达以及JNK，p38，细胞外信号调节激酶（ERK）1／2的磷酸化水平用Western印迹检测。结果 MTT及ELISA检测提示TIMP-3降低MC3T3-E1细胞存活率，诱导MC3T3-E1细胞凋亡。TIMP-1增加Fas、FasL蛋白表达，对Bax、Bcl-2蛋白表达无影响，但可诱导细胞色素c的释放及caspase-8、caspase-3的活化。TIMP-3促进p38和ERK磷酸化，而PD098059（ERK阻断剂）和SB203580（p38阻断剂）消除p38和ERK的促凋亡作用。结论 TIMP-3诱导MC3T3-E1细胞凋亡的信号途径为凋亡受体Fas介导，并有p38、ERK信号转导途径参与。

Recombinant protein of tissue inhibitor of metalloproteinase-3 induces apoptosis of mouse MC3T3-E1 osteoblasts

Objective To investigate the action of recombinant protein of tissue inhibitor of metalloproteinase-3(TIMP-3)on apoptosis of MC3T3-E1 osteoblasts.Methods Cell survival rate and apoptosis were measured by MTT and ELISA respectively.The expressions of Fas,FasL, Bcl-2,Bax,caspase-3,caspase-8, cytochrome c and phosphorylations of JNK,p38 and extracellular signal-regulated kinase(ERK)1/2 were analysed by Western blotting.Results TIMP-3 reduced survival rate of MC3T3-E1 cells and promoted apoptosis of MC3T3 E1 cells induced by serum deprivation in a dose-dependent manner.TIMP-3 increased expressions of Fas and FasL protein.TIMP-3 increased release of cytochrome c and activities of caspase-3 and caspase-8 in MC3T3-E1 cells. TIMP-3 activated phosphorylation of ERK and p38,while PD098059(ERK inhibitor)and SB203580(p38 inhibitor)abolished the apoptotic activity.Conclusion TIMP-3 can induce apoptosis of MC3T3-E1 cells by regulating Fas and Fasl expressions,and by promoting the release of cytochrome c as well as activation of caspase- 3 and -8,mediated via the ERK and p38 signaling pathway.