Kong Wei-Xia, Zhu Heng, Jiang Xiao-Xia, Li Hong, Liu Yuan-Lin, Wu Ying, Zhang Yi, Mao Ning
Department of Cell Biology, Institute of Basic Medical Sciences, Academy of Military Medical Sciences, Beijing 100850, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2010 Aug;18(4):981-5.
This study was purposed to investigate the effect of mitogen-activated protein kinase (MAPK) pathway on the osteoblast differentiation of mouse mesenchymal stem cells (MSCs), MSCs were isolated from mouse compact bone and serially passaged. After being cultured in osteogenic induction medium, the phosphorylation levels of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 were detected by Western blot. The effects of corresponding pathway inhibitors including PD98059, JNK II and SB203580 on alkaline phosphatase (ALP) and calcium accumulation in the osteoblastic differentiation of MSCs were determined by ALP staining and von kossa staining respectively. The results showed that MAPK pathway including ERK, JNK and p38 was activated in differentiation of MSCs into osteoblasts. ALP activity of MSCs increased in the early phase by addition of PD98059 treatment, whereas ALP activity and calcium accumulation were not observed via JNK II treatment. However, SB203580 strongly inhibited the ALP expression and the calcium accumulation. It is concluded that p38 plays a positive role in the osteogenic differentiation of MSCs, and ERK is probably a negative factor at the early phase of differentiation, but the effect of JNK is not essential.
本研究旨在探讨丝裂原活化蛋白激酶（MAPK）信号通路对小鼠间充质干细胞（MSCs）向成骨细胞分化的影响。从小鼠致密骨中分离出MSCs并进行连续传代培养。在成骨诱导培养基中培养后，通过蛋白质免疫印迹法检测细胞外信号调节激酶（ERK）、c-Jun氨基末端激酶（JNK）和p38的磷酸化水平。分别通过碱性磷酸酶（ALP）染色和冯科萨染色法，测定相应通路抑制剂（包括PD98059、JNK II和SB203580）对MSCs成骨分化过程中ALP和钙沉积的影响。结果显示，在MSCs向成骨细胞分化过程中，包括ERK、JNK和p38在内的MAPK信号通路被激活。添加PD98059处理后，MSCs的ALP活性在早期增加，而JNK II处理未观察到ALP活性和钙沉积。然而，SB203580强烈抑制ALP表达和钙沉积。结论：p38在MSCs成骨分化中起积极作用，ERK可能在分化早期起负性作用，但JNK的作用并非必需。
