中文摘要：

目的 研究P38丝裂原激活的蛋白激酶（P38MAPK）信号通路在压力调控骨髓间充质干细胞（BMSCs）膜片成软骨响应中作用.方法 将含有抗坏血酸培养基构建的兔BMSCs细胞膜片分为空白对照组和加压组（静态液压加载装置给予细胞膜片120 kPa、1 h/d、连续4d的压力刺激）,采用Western blot及real time-PCR检测P38MAPK信号通路的表达,real time-PCR技术检测成软骨基因的表达.结果 兔BMSCs传代后细胞生长状态稳定,呈梭形；成骨诱导后,茜素红染色可观察到矿化结节,碱性磷酸酶活性染色呈阳性,成脂诱导后油红O染色细胞内出现红色脂滴；Western blot结果显示,与对照组（0.165 ±0.035）比较,压力刺激下兔BMSCs细胞膜片中P38MAPK蛋白表达量（0.820 ±0.108）显著升高（P＜0.05）,同时real time-PCR结果表明：加压组兔BMSCs细胞膜片中P38MAPK的mRNA表达量（0.651 ±0.105）高于对照组（0.166±0.046） （P ＜0.05）,且成软骨基因（Sox-9、Aggrecan及Col-Ⅱ）的mRNA表达量（3.323±0.729、0.901±0.162、1.151±0.105）也明显高于对照组（0.541±0.121、0.335±0.094、0.466±0.158）（P＜0.05）.结论 P38MAPK信号通路在压力调控BMSCs膜片成软骨响应中起正调节作用.

英文摘要：

Objective To investigate the role of the 1＇38 mitogen activated protein kinases （P38MAPK） signal pathway in the mechanical pressure regulated chondrogenesis of bone marrow mesenchymal stem cell（BMSC） sheets. Methods The rabbit BMSCs sheets obtained after being cultured by standard medium with Vitamin C were divided into control group and pressure group. The rabbits BMSCs sheets in the latter group were treated with 120 KPa hydrostatic pressure for 1 h/day with 4 consecutive days,then the P38MAPK protein and gene expressions were examined by Western blot and real time-PCR, respectively. Real time-PCR was also used to measure the chondrogenic gene expressions in BMSCs sheets. Results The subcultured rabbit BMSCs grew well with typical shuttle shape. The mineralized nodules were observed with alizarin Bordeaux staining and the cells were positive to alkaline phosphates staining while the red lipid droplet existed in adipose cells with oil red O staining after adipose induction. In addtition,Western blot confirmed the higher protein expression of P38MAPK in rabbit BMSCs sheets in the pressure group（0. 820 ±0. 108） than that of the control group（0. 165 ±0. 035） （P 〈0.05）. Furthermore,the Real Time-PCR showed us that the pressure increased the mRNA expression of P38MAPK in rabbit BMSCs sheets（0. 651 ± 0. 105 ） when comparing withthe control ones（0. 166 ± 0. 046）, and the mRNA levels of chondrogenic genes（ Sox-9, Aggrecan and Col- II ） in rabbit BMSCs sheets in the pressure group （ 3. 323 ± 0. 729,0. 901 ± 0. 162,1. 151 ± 0. 105 ） were significantly higher than those of the control group （0. 541 ± 0. 121,0. 335 ± 0. 094,0. 466 ± 0. 158 ） （ P 〈 0. 05 ）. Conclusions The P38MAPK signal pathway plays a positive role in the mechanical pressure regulated chondrogenesis of BMSCs sheets.