Mfn2通过抑制内质网应激减轻椎间盘退变大鼠髓核细胞凋亡

Mfn2 Reduces Apoptosis of Nucleus Pulposus Cells in Rats with Intervertebral Disc Degeneration by Inhibiting Endoplasmic Reticulum Stress

目的研究Mfn2对椎间盘退变大鼠髓核细胞内质网应激及细胞凋亡的作用及机制。方法离体培养正常大鼠NP细胞为control组,离体培养椎间盘退变大鼠NP细胞分为model组、OE-Mfn2组、OE-NC组及4-PBA组。Western blot法检测Mfn2、PERK、p-PERK、eIF2α、p-eIF2α、ATF4、CHOP、GRP78、Bcl-2、Bax、caspase-3的蛋白水平;qRT-PCR检测Mfn2、PERK、eIF2α、ATF4mRNA水平;免疫共沉淀实验验证Mfn2与PERK互作关系;MTT检测细胞活力;流式细胞术检测细胞凋亡率。结果Mfn2可特异性结合PERK;与model组比较,OE-Mfn2组Mfn2、Bcl-2水平及细胞活力增加(P<0.05),PERK、p-PERK、eIF2α、p-eIF2α、ATF4、CHOP、GRP78、Bax、caspase-3水平及凋亡率降低(P<0.05)。结论Mfn2可通过降低ERS抑制椎间盘退变大鼠NP细胞凋亡。

Objective To study the effect and mechanism of Mfn2 on endoplasmic reticulum stress and apoptosis of nucleus pulposus cells in rats with intervertebral disc degeneration.Methods The NP cells of normal rats were cultured in vitro into control group.The NP cells were divided into model group,OE-Mfn2 group,OE-NC group and 4-PBA group.The protein levels of Mfn2,PERK,p-PERK,eIF2α,p-eIF2α,ATF4,CHOP,GRP78,Bcl-2,Bax and caspase-3 were detected by Western blot.The mRNA levels of Mfn2,PERK,eIF2αand ATF4 were detected by qRT-PCR.CO-IP was used to verify the interaction between Mfn2 and PERK.Cell viability was measured by MTT assay.Apoptosis rate was measured by flow cytometry.Results Mfn2 can specifically bind to PERK.Compared with model group,the levels of Mfn2,Bcl-2 and cell viability increased in OE-Mfn2 group(P<0.05),while the levels of PERK,p-PERK,eIF2α,p-eIF2α,ATF4,CHOP,GRP78,Bax,caspase-3 and apoptosis rate decreased in OE-Mfn2 group(P<0.05).Conclusion Mfn2 can inhibit the apoptosis of NP cells in rats with intervertebral disc degeneration by reducing ERS.