内质网应激相关凋亡信号在肥胖小鼠盆底肌损伤中的作用

Role of endoplasmic reticulum stress-associated apoptotic signaling in pelvic floor muscle injury in obese mice

目的:探究内质网应激(ERS)相关凋亡信号在肥胖小鼠盆底肌损伤中的作用。方法:自公共基因芯片数据库(GEO)下载数据集GSE6766,使用GEO2R在线分析工具和R软件筛选棕榈酸(PA)处理小鼠成肌细胞C2C12后的差异表达基因(DEGs),并对DEGs进行基因本体论(GO)富集分析和京都基因与基因组百科全书(KEGG)信号通路分析。高脂饮食喂养20周后取小鼠盆底肌,通过固定包埋切片及层黏连蛋白染色,统计小鼠盆底肌肌纤维横截面积;通过蛋白印迹法检测小鼠盆底肌组织内质网应激相关凋亡蛋白CHOP蛋白的表达水平。使用不同浓度(0、250、500、750μmol/L)的PA处理小鼠成肌细胞C2C12肌管24 h后提取细胞蛋白及总RNA,RT-qPCR法检测小鼠C2C12肌管中ERS信号通路蛋白GRP78及CHOP的mRNA表达水平,蛋白印迹法检测CHOP蛋白的表达水平。结果:PA处理C2C12肌管后的DEGs分析显示相关基因及通路富集在内质网应激相关信号通路。高脂饮食诱导小鼠盆底肌萎缩及CHOP蛋白表达增加。PA处理的C2C12细胞中内质网应激相关基因及蛋白表达增加。结论:内质网应激相关凋亡参与了高脂饮食诱导的肥胖小鼠中盆底肌损伤过程。

Objective:To investigate the role of endoplasmic reticulum stress(ERS)-related apoptotic signal-ing in pelvic floor muscle injury in obese mice.Methods:The dataset GSE6766 was downloaded from the public gene microarray database(GEO),and the differentially expressed genes(DEGs)after palmitic acid(PA)treatment of mouse myogenic cells with C2C12 were screened using the GEO2R online analysis tool and R software,and the DEGs were subjected to Gene Ontology(GO)enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway analysis.The cross-sectional area of pelvic floor muscle fibers was counted by fixation of embedded sections and lam-inin staining after 20 weeks of high-fat diet feeding,and the expression level of CHOP protein,an ERS-related apoptotic protein,was measured by protein blotting.The mRNA expression levels of ERS signaling pathway proteins GRP78 and CHOP in mouse C2C12 myotubes were detected by RT-qPCR.The expression level of CHOP protein was detected by protein blotting.Results:Analysis of DEGs after PA treatment of C2C12 myotubes showed related genes and pathways enriched in ERS-re-lated signaling.High-fat diet induced pelvic floor muscle atrophy and increased CHOP protein expres-sion in mice.Increased expression of ERS-related genes and proteins in PA-treated C2C12 cells were found.Conclusion:Endoplasmic reticulum stress apoptosis is involved in high-fat diet-induced pelvic floor muscle injury in obese mice.