中文摘要：

目的探讨新型机械激活离子通道蛋白Piezol是否参与调控关节软骨损伤患者软骨细胞的过度凋亡及Piezol介导的细胞凋亡是否以经典丝裂原激活的蛋白激酶（MAPK）信号通路细胞外反应激酶（ERK）1／2为下游信号通路启动细胞凋亡。方法体外培养关节软骨损伤患者退变软骨细胞，利用多通道细胞牵张应力加载系统FX-4000T处理软骨细胞，根据预实验结果分成0、2、12、24、48h牵张应力组和相应的抑制剂红玫瑰毛蜘蛛来源刮刀样机械敏感毒剂4型（GsMTx4）组。实时聚合酶链反应（RT—PCR）检测不同力学条件刺激下各组细胞的Piezol和ERKl／2的表达量，以及抗凋亡基因B细胞淋巴瘤／白血病-2（Bax／Bcl．2）及凋亡效应蛋白（caspase）．3的表达量。免疫荧光定位Piezol蛋白及ERKl／2在软骨细胞的表达位置。检测各分组的凋亡情况。结果RT—PCR结果显示PizeolmRNA在退变软骨中有少量表达，12h表达量增加，24h表达量达到峰值，但48h表达量下降。GsMTx4处理后的各组表达均下降。ERK1／2、Bax／Bcl-2、caspase-3的表达也出现相同趋势，2h加力组早期细胞凋亡率开始增加（0．1981比0．0214，P=0．0137），12h加力组晚期凋亡率开始增加，24h]J1]力组的晚期细胞凋亡率最高，但48h加力组凋亡率比24h加力组有所降低（0．4971比0．7431，q=0．0359）。Piezol蛋白可以在细胞核和细胞质表达，ERK1／2在细胞质表达较多。结论机械敏感性离子通道Piezol参与骨性关节损伤的软骨细胞晚期凋亡过程，且通过MAPK／ERKl／2的经典MAPK信号通路启动细胞的凋亡过程。

英文摘要：

Objective To invstigate the mechanism of new mechanically-activated cation channel protein （ Piezol ） can cause the apoptosis of the human chondrocytes under compressive loading, using a Flexercell unit by activating classical Mitogen-activated protein kinase （MAPK） signal pathyway （ERK1/2）. Methods Primary human chondrocytes were isolated,cultured,and then subjected to the static compressive loading for 0,2,12,24,48 h, respectively. The expressions of Piezol and the ERKI/2 were assessed by reverse transcription-polymerase chain reaction（PT-PCR） , as well as the apoptosis gene B cell lymphoma/leukemia-2 （ Bcl-2 ） Bel-associated X protein （ Bax）. In addition, Piezol inhibitor, Grammostola spatulata mechanotoxin 4 （GsMTx4）, was used to block Piezol, served as a positive control. The immunofluorescence was used to locate the expression of Piezol protein and ERK1/2. AnnexinV-PI was used to detect the apoptosis of chondrocytes. Results The expression of the Piezol in chondrocytesis was weak, the 12 h group was significant increased（0. 198 1 vs 0. 021 4,P 〈0. 05）, the 24 h group was the highest expression while the expression of the 48 h group was lower than the 24 h group, as well as the ERK1/2, Bcl-2 and caspase3. The result of AV-PI had shown that the 2 h group had increased early stage of apoptosis. The 12 h group had increased late stage of apoptosis, and the 24 h group＇s apoptotic rate was the highest, while the apoptotic rate of the 48 h group was lower than the 24 h group（0. 497 1 vs 0. 743 1 ,q = 0. 035 9）. The GsMTx4 could inhibit the late stage of apoptosis, and the location of the Piezol was expressed in the nucleus and cytoplasm of the chondrocytes. Conclusions Piezol plays an important role in the apoptosis of the human chondrocyte through the classic MAPK/ERK1/2 signal pathway.