体液因子及其相关miRNA与慢性阻塞性肺疾病合并外周骨骼肌功能障碍的关系

Relationship between Humoral Factors and Their Related miRNA and COPD Combined with PSMD

目的分析体液因子〔肌细胞增强因子2(MEF2)A、胰岛素样生长因子1(IGF-1)、组蛋白去乙酰化酶(HDAC)4、血清应答因子(SRF)〕及其相关miRNA与慢性阻塞性肺疾病(COPD)合并外周骨骼肌功能障碍(PSMD)的关系。方法本实验时间为2021年12月至2022年9月。将11只健康雄性C57BL/6小鼠随机分为对照组(n=6)与模型组(n=5)。对照组小鼠自由进食和饮水,不做任何处理,模型组小鼠采用烟熏法构建COPD合并PSMD模型。观察小鼠大体情况,检测小鼠肺功能指标〔包括50毫秒用力呼气容积(FEV_(50))/用力肺活量(FVC)、每分通气量(MV)、气道阻力(AR)、动态肺顺应性(Cdyn)、吸气峰流量(PIF)、呼气峰流量(PEF)〕,采用HE染色检测小鼠胸大肌组织肌纤维数量、肌纤维总面积、横切肌纤维平均面积,采用Western blot法检测小鼠胸大肌组织中MEF2A、IGF-1、HDAC4、SRF表达水平,预测Mef2a、Igf-1、Hdac4、Srf基因的miRNA,采用qPCR法检测小鼠mmu-miR-466I-3p、mmu-miR-705表达水平。结果干预过程中,模型组小鼠逐渐出现食欲不振,毛发逐渐失去光泽且颜色发黄,精神萎靡,活动量明显减少,部分小鼠出现了打喷嚏症状;且烟熏时小鼠喜欢扎堆,倦怠蜷缩,出汗明显,腹部胀大,呼吸急促,出现点头运动甚至张口呼吸。干预2、3、4、5、6个月时,模型组小鼠体质量小于对照组(P<0.05)。模型组小鼠FEV_(50)/FVC低于对照组,MV、Cdyn小于对照组,AR大于对照组,PIF、PEF慢于对照组(P<0.05)。模型组小鼠胸大肌组织肌纤维数量少于对照组,肌纤维总面积、横切肌纤维平均面积小于对照组(P<0.05)。对照组和模型组小鼠胸大肌组织中MEF2A、HDAC4、SRF表达水平比较,差异无统计学意义(P>0.05);模型组小鼠胸大肌组织中IGF-1表达水平高于对照组(P<0.05)。没有预测到任何关于Igf-1基因的miRNA,Mef2a、Srf基因共同受mmu-miR-466l-3p调控,Mef2a、Hdac4基因共同受mmu-miR-705调控。对照组和模型组小鼠mmu-miR-466I-3p、mmu-miR-705表达水平比较,差异无统计学意义(P>0.05)。结论IGF-1与COPD合并PSMD可能有关,而MEF2A、SRF、HDAC4与COPD合并PSMD可能无关,且调控Mef2a、Hdac4、Srf基因的mmu-miR-466I-3、mmu-miR-705与COPD合并PSMD可能无关。

Objective To analyze the relationship between humoral factors[myocyte enhancement factor 2(MEF2)A,insulin-like growth factor 1(IGF-1),histone deacetylase(HDAC)4,serum response factor(SRF)]and their related miRNA and chronic obstructive pulmonary disease(COPD)combined with peripheral skeletal muscle dysfunction(PSMD).Methods This experiment was conducted from December 2021 to September 2022.Eleven healthy male C57BL/6 mice were randomly divided into control group(n=6)and model group(n=5).Mice in the control group ate and drank freely without any treatment,and mice in the model group were smoked to construct COPD combined with PSMD model.The general condition of the mice was observed,and the pulmonary function indexes[including forced expiratory volume in 50 millisecond(FEV_(50))/forced vital capacity(FVC),minute ventilation volume(MV),airway resistance(AR),dynamic lung compliance(Cdyn),peak inspiratory flow(PIF),peak expiratory flow(PEF)]of the mice were detected.HE staining was used to detect the number of muscle fibers,the total area of muscle fibers and the average area of cross-cut muscle fibers in pectoralis major muscle tissue of mice.Western blot was used to detect the expression levels of MEF2A,IGF-1,HDAC4 and SRF in pectoralis major muscle tissue of mice.The miRNA of Mef2a,Igf-1,Hdac4 and Srf genes was predicted,and the expression levels of mmu-miR-466I-3p and mmu-miR-705 of mice were detected by qPCR.Results During the intervention process,the mice in the model group gradually showed loss of appetite,hair gradually lost luster and yellow color,listless spirit,activity decreased significantly,and some mice showed symptoms of sneezing;and when smoking,mice liked to huddle together,were tired and curled up,sweated obviously,their stomachs suelled,their breathing became rapid,and they nodded or even opened their mouths to breathe.At 2,3,4,5 and 6 months of intervention,the body mass of mice in model group was less than that in control group(P<0.05).FEV_(50)/FVC,MV and Cdyn in model group were lower than those in control group,RI was higher than that in control group,PIF and PEF were slower than those in control group(P<0.05).The number of muscle fibers in pectoralis major muscle tissue in the model group was less than that in the control group,the total area of muscle fibers and the average area of cross-cut muscle fibers were smaller than those in the control group(P<0.05).There was no significant difference in the expression levels of MEF2A,HDAC4 and SRF in pectoralis major muscle tissue between control group and model group(P>0.05).The expression level of IGF-1 in pectoralis major muscle tissue in the model group was higher than that in the control group(P<0.05).No miRNA related to Igf-1 gene was predicted,Mef2a and Srf genes were jointly regulated by mmu-miR-466l-3p,and Mef2a and Hdac4 genes were jointly regulated by mmu-miR-705.There was no significant difference in the expression levels of mmu-miR-466I-3p and mmu-miR-705 between control group and model group(P>0.05).Conclusion IGF-1 may be associated with COPD combined with PSMD,while MEF2A,SRF,HDAC4 may be unrelated to COPD combined with PSMD,and mmu-miR-466I-3 and mmu-miR-705,which regulate Mef2a,Hdac4,and Srf genes,may be unrelated to COPD combined with PSMD.