摘要
目的探讨急性呼吸窘迫综合征(ARDS)中内质网应激(ERs)诱导的铁死亡机制。方法为了确定LPS对小鼠毛细血管肺泡上皮细胞(MLE12细胞)氧化应激和Fe 2+水平的影响,用LPS(0、1、2、5μg/ml)处理细胞24 h。将MLE12细胞分为对照(Con)组、脱铁抑制剂(Fer-1)组、LPS组和LPS+Fer-1组以验证铁死亡在脂多糖(LPS)诱导的细胞死亡中的作用。LPS+Fer-1组用10μmol/L Fer-1预处理6 h,随后将细胞暴露于5μg/ml LPS 24 h;Con组用融媒DMSO处理24 h,Fer-1组用10μmol/L Fer-1预处理6 h,随后用DMSO处理24 h;LPS组将细胞暴露于5μg/ml LPS 24 h。将MLE12细胞分为Con+载体(Vector)组、Con+序列相似性家族134成员B(FAM134B)组、LPS+Vector组、LPS+FAM134B组,细胞用Vector或FAM134B过表达质粒转染48 h后,暴露或不暴露于5μg/ml LPS 24 h。使用CCK-8法测定细胞活力;测量不同组的丙二醛(MDA)、谷胱甘肽和铁的水平,以及铁死亡标志物[环加氧酶2(PTGS2)、谷胱甘肽过氧化物酶4(GPX4)]和ERs标志物[葡萄糖调节蛋白78(GRP78)、活化转录因子4(ATF4)和C/EBP同源蛋白(CHOP)]的蛋白水平;为了进一步证实体外细胞实验结果,将40只小鼠随机分成Con+Vector组、Con+FAM134B组、LPS+Vector组、LPS+FAM134B组,每组10只,在LPS+Vector组、LPS+FAM134B组小鼠中建立LPS诱导的脓毒症模型,并通过免疫荧光染色和蛋白质印迹评估肺组织中GPX4和ERs水平。结果LPS处理的MLE12细胞中PTGS2和MDA水平以剂量依赖性增加,GPX4和谷胱甘肽(GSH)水平剂量依赖性降低;与LPS组相比,LPS+Fer-1组细胞活力、GPX4和GSH水平增加(P<0.05),PTGS2蛋白水平和MDA水平降低(P<0.05);与LPS+Vector组相比,LPS+FAM134B组细胞活力增加(P<0.05),MDA水平和PTGS2蛋白水平降低(P<0.05),GPX4和GSH水平增加(P<0.05);动物实验中,与LPS+Vector组相比,LPS+FAM134B组小鼠肺组织中4-HNE、ATF4和CHOP表达水平降低(P<0.05),GPX4、FAM134B表达水平增加(P<0.05)。结论LPS以剂量依赖的方式诱导MLE12细胞铁死亡和ERs通过激活内质网自噬相关FAM134B受体有助于抑制ERs,并减轻细胞铁死亡。
Objective To explore the mechanism of ferroptosis induced by endoplasmic reticulum stress(ERs)in acute respiratory distress syndrome(ARDS).Methods In order to determine the effects of LPS on oxidative stress and Fe 2+level of mouse capillary alveolar epithelial cells(MLE12 cells),the cells were treated with LPS(0,1,2,5μg/ml)for 24 h.To verify the role of ferroptosis in lipopolysaccharide(LPS)-induced cell death,MLE12 cells were divided into control(Con)group,iron removal inhibitor(Fer-1)group,LPS group and LPS+Fer-1 group.LPS+Fer-1 group was pretreated with 10μmol/L Fer-1 for 6 h,then the cells were exposed to 5μg/ml LPS for 24 h.Con group was treated with solvent DMSO for 24 h.Fer-1 group was pretreated with 10μmol/L Fer-1 for 6 h,and then treated with DMSO for 24 h.The cells in LPS group were exposed to 5μg/ml LPS for 24 h.The MLE12 cells were divided into three groups:Con+Vector group,Con+sequence similarity family 134 member B(FAM134B)group,LPS+Vector group and LPS+FAM134B group.After transfected with vector or FAM134B overexpression plasmid for 48 h,the cells were exposed or not exposed to 5μg/ml LPS for 24 h.Cell viability was measured by CCK-8.The levels of malondialdehyde(MDA),glutathione and iron,the protein levels of ferroptosis markers[cyclooxygenase 2(PTGS2),glutathione peroxidase 4(GPX4)]and ERs markers[glucose regulatory protein 78(GRP78),activated transcription factor 4(ATF4)and C/EBP homologous protein(CHOP)]were measured in different groups.In order to further confirm the results of in vitro cell experiments,40 mice were randomly divided into Con+Vector group,Con+FAM134B group,LPS+Vector group and LPS+FAM134B group,with 10 mice in each group.LPS-induced sepsis models were established in LPS+Vector group and LPS+FAM134B group,and the levels of GPX4 and ERs in lung tissue were evaluated by immunofluorescence staining and protein blot.Results LPS treatment increased the levels of PTGS2 and MDA,and decreased the levels of GPX4 and GSH in MLE12 cells in a dose-dependent manner.Compared with LPS group,the cell viability,GPX4 and GSH levels in LPS+Fer-1 group increased significantly(P<0.05),while the PTGS2 protein level and MDA level decreased significantly(P<0.05).Compared with LPS+Vector group,LPS+FAM134B group significantly increased cell viability(P<0.05),decreased PTGS2 protein level(P<0.05)and increased GPX4 level(P<0.05).At the same time,the level of MDA in LPS+FAM134B group was lower than that in LPS+Vector group(P<0.05),and the level of GSH was higher than that in LPS+Vector group(P<0.05).In animal experiment,compared with LPS+Vector group,the expression levels of 4-HNE,ATF4 and CHOP in lung tissue of LPS+FAM134B group decreased significantly(P<0.05),and the expression levels of GPX4,FAM134B group increased significantly(P<0.05).Conclusion LPS induces ferroptosis and ERs in MLE12 cells in a dose-dependent manner.Activating the endoplasmic reticulum autophagy associated FAM134B receptor helps to inhibit ERs and alleviate cell ferroptosis.
作者
金子琦
唐波
吴章宏
肖宝
刘斌
钟扬
胡霞
Jin Ziqi;Tang Bo;Wu Zhanghong;Xiao Bao;Liu Bin;Zhong Yang;Hu Xia(Dept of Emergency Department,Changsha First Hospital(Changsha Hospital Affiliated to Xiangya Hospital,Central South University),Changsha 410008;Dept of Critical Care Medicine,Hunan Provincial Brain Hospital(Hunan Second People′s Hospital),Changsha 410007)
出处
《安徽医科大学学报》
CAS
北大核心
2024年第3期491-499,共9页
Acta Universitatis Medicinalis Anhui
基金
湖南省自然科学基金(编号:2021JJ70322)。
关键词
内质网应激
急性呼吸窘迫综合征
脂多糖
肺泡上皮细胞
铁死亡
内质网自噬
endoplasmic reticulum stress
acute respiratory distress syndrome
lipopolysaccharide
alveolar epithelial cells
ferroptosis
endoplasmic reticulum autophagy
