沉默FSTL1减少衣霉素诱导软骨细胞内质网应激及细胞凋亡

FSTL1 silence reduces tunicamycin-induced endoplasmic reticulum stress and apoptosis in chondrocytes

目的探讨沉默卵泡抑素样蛋白1(FSTL1)对衣霉素诱导软骨细胞内质网应激(ERS)及细胞凋亡的影响。方法取兔膝关节软骨,收集并培养软骨细胞,将细胞分为对照组、衣霉素组、衣霉素+siRNA-FSTL1组和衣霉素+siRNA-NC组;MTT法检测细胞增殖;流式细胞计量术检测细胞凋亡;实时荧光定量PCR检测细胞中FSTL1、Bcl-2和Bax mRNA含量;Western blot检测细胞中PERK、p-PERK、GRP78、ATF4、CHOP、Cal、e IF2α和p-e IF2α蛋白表达。结果与衣霉素组和衣霉素+siRNA-NC组相比,衣霉素+siRNA-FSTL1组细胞增殖能力显著提高(P<0.05),细胞凋亡率降低(P<0.05);细胞中FSTL1和Bax mRNA相对表达量均降低,而Bcl-2 mRNA相对表达量均升高(P<0.05);细胞中PERK和e IF2α蛋白相对表达量均升高,而p-PERK、GRP78、ATF4、CHOP、Cal和p-e IF2α蛋白相对表达量均降低(P<0.05)。结论特异性沉默软骨细胞中FSTL1可有效减少ERS及细胞凋亡,其机制可能与抑制PERK信号通路有关。

Objective To investigate the effects of specific silencing of follistatin-like protein 1（ FSTL1） on tunicamycin-induced endoplasmic reticulum stress and apoptosis in chondrocytes. Methods Rabbit knee articular cartilage was collected. Chondrocytes were harvested and cultured. The cells were divided into control group,tunicamycin group,tunicamycin ＋ siRNA-FSTL1 group and tunicamycin ＋ siRNA-NC group. The cell proliferation was detected by MTT assay. Cell apoptosis was detected by flow cytometry. The expression of FSTL1,Bcl-2 and Bax genes was detected by real-time fluorescence quantitative polymerase chain reaction. The expression of PERK,p-PERK,GRP78,ATF4,CHOP,Cal,e IF2α and p-e IF2α protein was detected by Western blot. Results Compared with the tunicamycin group and tunicamycin＋siRNA-NC group,the cell proliferation abilities in tunicamycin＋siRNA-FSTL1 group were significantly increased（ P〈0. 05）,the apoptotic rate was decreased（ P〈0. 05）,the relative expression level of FSTL1 and Bax mRNA was decreased,while the relative expression level of Bcl-2 mRNA was increased（ P〈0. 05）,the relative expression levels of PERK and e IF2α proteins were increased,whilethe relative expression levels of p-PERK,GRP78,ATF4,CHOP,Cal and p-e IF2α proteins were decreased（ P〈0. 05）. Conclusions Specific silencing of FSTL1 in chondrocytes may effectively reduce ERS and apoptosis. The mechanism is related to inhibition of PERK signal pathway.