Txndc5介导雌激素诱导的小鼠前成骨细胞MC3T3-E1增殖加快  

Txndc5 mediates estrogen accelerated proliferation of murine pre-osteoblast MC3T3-E1

作　　者：王乐[1] 卢雅彬[1] 熊霞辉[1] 朱宁[2] 陈梅红[1] 

机构地区：[1]中国医学科学院基础医学研究所 北京协和医学院 基础医学院 生物化学与分子生物学系 医学分子生物学国家重点实验室,北京100005 [2]中国医学科学院基础医学研究所北 京协和医学院 基础医学院 生物化学与分子生物学系 医学分子生物学国家重点实验室,北京100005

出　　处：《基础医学与临床》2012年第7期761-766,共6页Basic and Clinical Medicine

基　　金：国家自然科学基金(30971458;31150005)

摘　　要：目的研究Txndc5基因在小鼠前成骨细胞增殖中的作用。方法用雌激素诱导小鼠前成骨细胞系MC3T3-E1,或在MC3T3-E1细胞中分别用质粒载体过表达Txndc5和用siRNA抑制Txndc5的表达后,Western blot检测Txndc5和细胞周期蛋白水平,荧光实时定量PCR检测Cyclin A的mRNA水平,MTS法和细胞计数法检测细胞增殖速度,流式细胞术检测细胞周期。结果雌激素诱导MC3T3-E1增殖加快时,Txndc5的蛋白水平亦上升。抑制Txndc5的表达阻止雌激素的促细胞增殖作用。过表达Txndc5使MC3T3-E1细胞增殖速度加快,S期细胞比例增加,同步化细胞进入细胞周期18 h时,过表达Txndc5组Cyclin A的表达升高,且S期细胞比例为18.69%±4.08%,而对照组仅为8.15%±3.68%。抑制Txndc5的表达则使MC3T3-E1细胞增殖速度减慢,S期细胞比例减少,Cyclin A的表达下降。抑制Cyclin A的表达减弱Txndc5的促细胞增殖作用。结论 Txndc5通过上调Cyclin A的表达介导雌激素的促前成骨细胞增殖作用。Objective To investigate the role of Txndc5 in murine pre-osteoblast proliferation. Methods Murine pre-osteoblast cell line MC3T3-E1 was treated with estrogen. Txndc5 was either over-expressed by plasmid vector or knocked down by siRNA in MC3T3-E1 cell. The protein level of Txndc5 and Cyclins was evaluated by Western blot. The mRNA level of Cyclin A was measured by quantitative real-time PCR. Cell proliferation rate was deter- mined by MTS assay and cell counting. Cell cycle distribution was revealed by flow cytometry analysis. Results The protein level of Txndc5 was up-regulated in estrogen-induced MC3T3-E1 proliferation. Knockdown of Txndc5 blocked estrogen-induced cell proliferation. Over-expression of Txndc5 accelerated MC3T3-E1 cell proliferation, increased the proportion of cells in S phase. Eighteen hours after the synchronized cells entered cell cycle, the expression of Cyclin A was up-regulated, and the percentage of cells in S phase was 18.69% ±4. 08% in cellsover-expressing Txndc5, which was only 8. 15%±3.68% in control cells. On the other hand, knockdown of Txndc5 inhibited the growth of MC3T3-E1 cells, decreased the proportion of cells in S phase, and down-regulated the expression of Cyclin A. Knockdown of Cyclin A attenuated the cell proliferation-enhancing effect of Txndc5. Conehmions Txndc5 mediates estrogen-accelerated pre-osteoblast proliferation through up-regulation of Cyclin A.

关 键 词：Txndc5 MC3T3-E1细胞 细胞增殖 雌激素 

分 类 号：R363[医药卫生—病理学]