IL-1β通过加重脂质诱导的内质网应激导致人系膜细胞损伤

IL-1β induces human mesangial cell injury via exacerbating lipid-induced endoplasmic reticulum stress

目的:探讨白细胞介素1β(IL-1β)加重脂质诱导的内质网应激(ERS)而导致人肾小球系膜细胞(HMCs)损伤的分子机制。方法:将HMCs分为对照组、高脂组(LDL)、IL-1β+高脂组(IL-1β+LDL)及4-苯基丁酸(4-PBA)干预组(4-PBA+IL-1β+LDL)。油红O染色检测HMCs胞内脂质沉积;real-time PCR检测葡萄糖调节蛋白78(GRP78)、蛋白激酶R样内质网激酶(PERK)和α-平滑肌肌动蛋白(α-SMA)mRNA水平;免疫细胞化学分析GRP78蛋白水平;Western blotting检测NF-κB p65水平;ELISA法测定细胞培养上清IL-6和TGF-β1含量。结果:与LDL组相比,IL-1β+LDL组胞内脂质沉积、GRP78 mRNA与蛋白水平、PERK mRNA水平、NF-κB p65水平及IL-6分泌量均显著增高(均P<0.05);4-PBA可减少胞内脂质沉积,降低GRP78 mRNA与蛋白及PERK mRNA水平,抑制NF-κB p65的表达,减少IL-6的分泌(均P<0.05 vs IL-1β+LDL组)。与LDL组相比,IL-1β+LDL组α-SMA mRNA表达增高(P<0.05),4-PBA可显著降低其表达(P<0.05 vs IL-1β+LDL组)。结论:IL-1β可加重脂质诱导的ERS,从而导致细胞损伤。

AIM： To investigate the molecular mechanism that interleukin-1 beta（IL-1β） exacerbates lipidinduced endoplasmic reticulum stress（ERS） and the injury of human mesangial cells（HMCs）.METHODS： HMCs were cultured and divided into control group,low-density lipoprotein（LDL） group,IL-1β ＋ LDL group and 4-phenyl butyric acid（4-PBA） ＋ IL-1β ＋ LDL group.Oil red O staining was used to evaluate the accumulation of lipid droplet in the cells.The mRNA levels of glucose-regulated protein 78（GRP78）,protein kinase R-like endoplasmic reticulum kinase（PERK） and α-smooth muscle actin（α-SMA） were examined by real-time PCR.Immunocytochemistry was used to observe GRP78 expression.The protein level of NF-κB p65 was measured by Western blotting.The releases of IL-6 and TGF-β1 in the culture supernatants of HMCs were detected by ELISA.RESULTS： Compared with LDL group,the intracellular lipid accumulation,the mRNA levels of GRP78 and PERK,the protein expression of GRP78 and NF-κB p65,and the release of IL6 were significantly increased in IL-1β ＋ LDL group.Dramatically reduced intracellular lipid accumulation,down-regulated GRP78 and PERK mRNA expression,decreased protein levels of GRP78 and NF-κB p65,and suppressed IL-6 release were observed in 4-PBA ＋ IL-1β ＋ LDL group as compared with IL-1β ＋ LDL group.The mRNA level of α-SMA was higher in IL-1β ＋ LDL group than that in LDL group,and that in 4-PBA ＋ IL-1β ＋ LDL group was significantly depressed.CONCLUSION： IL-1β exacerbates lipid-induced ERS,thus promoting the injury of HMCs.