IL-1β诱导内质网应激增加人软骨细胞凋亡

IL-1β induced endoplasmic reticulum stress increases the apoptosis of human chondrocyte

目的分析炎性因子(IL-1β与TNF-α)对内质网应激(ERS)的影响以及与骨关节软骨细胞凋亡的关系,探讨相关分子机制。方法收集正常与OA患者骨关节软骨组织各20例,RT-PCR法检测软骨组织中炎性因子IL-1β、TNF-α及ERS相关因子GRP78、CHOP的mRNA水平。Western blot法检测体外培养软骨细胞中GRP78、CHOP、ATF4和caspase-3表达,TUNEL法检测细胞凋亡。结果与对照组相比,OA患者骨关节软骨组织中IL-1β、TNF-α与GRP78、CHOP的mRNA表达水平均显著上调(P<0.01),IL-1β与GRP78、CHOP的高表达呈显著正相关(P<0.05)。体外实验表明,IL-1β(2 ng/L)作用下,软骨细胞GRP78、CHOP、ATF4表达水平及细胞凋亡水平较对照组均显著增高(P<0.01);TNF-α作用下,GRP78、caspase-3表达水平及细胞凋亡水平较对照组显著上调(P<0.01)。结论 2 ng/L及更高浓度的IL-1β可激活ATF4-CHOP介导的ERS反应而诱导软骨细胞凋亡。

Objective To analyze the effects of inflammation factors （IL-1β, TNF-α） on endoplasmic reticulum stress （ERS） and the association with osteoarticular chondrocyte apoptosis. Methods Osteoarticular cartilage tissues were collected from control and OA patients. RT-PCR was performed to measure the mRNA level of IL-1β, TNF-α, GRP78 and CHOP in cartilaginous tissues. Western blot was used to evaluate the expression of GRP78, CHOP, ATF4 and caspase-3 in chondrocytes. The apoptosis of chondrocyte was analyzed by TUNEL. Results Compared with control, mRNA level of IL-1β, TNF-α, GRP78 and CHOP in OA was significantly higher （P 〈 0. 01 ）, while the high expression of IL- 1β was positively correlated to GRP78 and CHOP （ P 〈0. 05 ）. In vitro, GRP78, CHOP, ATF4 expression and chondrocyte apoptosis significantly increased in response to the treatment of IL-1β （2 ng/L） （P 〈 0. 01 ）. In addition, the expression of GRP78, caspase-3 and chondrocyte apoptosis were significantly higher after incubation with TNF-α （P 〈 0. 01 ）. Conclusions 2 ng/L and higher dosage of IL- 1β triggered ATF4-CHOP-mediated ERS to induce chondrocyte apoptosis.