自然衰老小鼠骨髓间充质干细胞增龄性改变的研究

Age-related changes of bone marrow mesenchymal stem cells of aged mice

目的:探讨自然衰老小鼠骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMMSCs)在衰老过程中生物学特点的改变。方法:分离、培养年轻(2月龄)、年老(16月龄)C57/BL6J小鼠的BMMSCs,经干细胞表面分子鉴定后,Western Blot检测2组BMMSCs的Tert、Acetyl-P53蛋白表达水平;氧化应激活性氧(ROS)试剂盒检测ROS表达水平;流式细胞仪检测并比较两组细胞的增殖、凋亡状态。结果:年轻、年老小鼠BMMSCs阳性表达Sca-1,阴性表达CD34、CD45,符合间充质干细胞表达特性;年老小鼠BMMSCs Tert蛋白表达水平明显低于年轻组(P<0.05),Acetyl-P53蛋白表达水平明显高于年轻组(P<0.05);年老细胞ROS表达水平明显高于年轻组;年老细胞的增殖能力明显低于年轻组(P<0.05),而凋亡水平则明显高于年轻组(P<0.05)。结论:年老小鼠BMMSCs出现增龄性变化,这些变化可能在骨衰老中起着重要作用。

AIM： To investigate the biological changes of bone marrow mesenchymal stem cells （BMMSCs） of mice during aging. METHODS： BMMSCs were isolated and cultured from 2 month（young） and 16 month（aged） old mice respectively. BMMSCs were identified with MSC-related monoclonal antibodies by flow cytometric analysis. The expression of Tert and Acetyl-P53 protein in BMMSCs were tested by Western Blot. ROS level was determined by ROS kit. Flow cytometry was performed to compare the proliferation ability and apoptosis between the young and the aged BMMSCs. RESULTS： Positive expression of stem cell antigen Sca-1 and negative expression of CD34 and CD45 were identified in BMMSCs of the young and the aged mice. Aged BMMSCs exhibited an increase of Acetyl-P53 expression（P 〈 0.05） and a decrease of Tert expression （P 〈 0. 05） as compared with young BMMSCs. Cellular ROS level of aged BMMSCs was higher than that of young BMMSCs. Aged BMMSCs showed reduced proliferation ability（P 〈0.05） and increased apoptosis（P 〈0.05） than young BMMSCs. CONCLUSION： Aged BMMSCs demonstrated aging changes which may play an important role in bone aging.