Huang C, Zhang G F, Han J, Liao G J, Zou B G
Department of Orthopedic Surgery, Yan Tai Shan Hospital, Shandong, China.
J Biol Regul Homeost Agents. 2016 Apr-Jun;30(2):565-9.
This study was carried out to explore the age-related changes of bone marrow mesenchymal stem cells (BMMSCs) in mice as well as the influence of autophagy on the age-related changes of BMMSCs. BMMSCs aging-associated protein acetylation P53, P21 and P16 expressions in young and senile mice, protein expression of telomerase reverse transcriptase (TERT) as well as reactive oxygen species (ROS) level were detected and compared; the expression of BMMSCs autophagy associated gene, autophagy related protein molecule and LC3 molecule were detected; the influence of differently concentrated rapamycin and 3-MA on BMMSCs autophagy level was observed to select effective concentrations; the influence of rapamycin and 3-MA on BMMSCs cell cycle-related gene expression, apoptosis related gene expression and ROS level were discussed. Results revealed that the senile BMMSCs group had higher acetylation P53, P21 and P16 expression and fluorescence intensity than the young group, but its TERT expression, Beclin1 and LC3 gene expression and fluorescence intensity were lower than the young group. Both rapamycin and 3-MA inhibited CyclinD1 (CCND1) and CyclinD2 (CCND2) expression. Rapamycin promoted the expression of apoptosis-related genes Caspase3 and Caspase8 in the senile group, while 3-MA inhibited them in both the young and senile groups. It can therefore be concluded that senile BMMSCs have multiple age-related changes, performing as decrease of osteogenic capability and multiplication capacity, increase of acetylation P53, P21 and P16 protein expression, apoptosis and ROS level as well as decrease of telomerase activity. Furthermore, the autophagy level in senile BMMSCs reduced compared with young cells; autophagy activation can decrease ROS level and autophagy suppression improves ROS level; and autophagy regulation affects cell cycle and apoptosis.
本研究旨在探讨小鼠骨髓间充质干细胞（BMMSCs）与年龄相关的变化以及自噬对BMMSCs与年龄相关变化的影响。检测并比较了年轻和老年小鼠中BMMSCs衰老相关蛋白乙酰化P53、P21和P16的表达、端粒酶逆转录酶（TERT）的蛋白表达以及活性氧（ROS）水平；检测了BMMSCs自噬相关基因、自噬相关蛋白分子和LC3分子的表达；观察了不同浓度雷帕霉素和3-甲基腺嘌呤（3-MA）对BMMSCs自噬水平的影响以选择有效浓度；探讨了雷帕霉素和3-MA对BMMSCs细胞周期相关基因表达、凋亡相关基因表达和ROS水平的影响。结果显示，老年BMMSCs组的乙酰化P53、P21和P16表达及荧光强度高于年轻组，但其TERT表达、Beclin1和LC3基因表达及荧光强度低于年轻组。雷帕霉素和3-MA均抑制细胞周期蛋白D1（CCND1）和细胞周期蛋白D2（CCND2）的表达。雷帕霉素促进老年组凋亡相关基因Caspase3和Caspase8的表达，而3-MA在年轻组和老年组中均抑制它们的表达。因此可以得出结论，老年BMMSCs有多种与年龄相关的变化，表现为成骨能力和增殖能力下降、乙酰化P53、P21和P16蛋白表达增加、凋亡和ROS水平升高以及端粒酶活性降低。此外，老年BMMSCs中的自噬水平与年轻细胞相比降低；自噬激活可降低ROS水平，自噬抑制可提高ROS水平；自噬调节影响细胞周期和凋亡。
