高脂膳食对小鼠呼吸功能和膈肌纤维的影响及其线粒体机制  

Effect of high‑fat diet on respiratory function and diaphragm fibers in mice and its mitochondrial mechanism

作　　者：李宁[1] 李红鹏 张本炎[2] 张柳 沈继敏[1] 李庆云[1] Li Ning;Li Hongpeng;Zhang Benyan;Zhang Liu;Shen Jimin;Li Qingyun(Department of Respiratory and Critical Care Medicine,Ruijin Hospital,Shanghai Jiaotong University School of Medicine,Shanghai 200025,China;Department of Pathology,Ruijin Hospital,Shanghai Jiaotong University School of Medicine,Shanghai 200025,China)

机构地区：[1]上海交通大学医学院附属瑞金医院呼吸与危重症医学科,上海200025 [2]上海交通大学医学院附属瑞金医院病理科,上海200025

出　　处：《中华医学杂志》2021年第36期2893-2899,共7页National Medical Journal of China

基　　金：国家自然科学基金(81770084、81670081);上海市卫生健康委员会项目(202040112);国家重点研发计划(2018YFC1311900)。

摘　　要：目的探讨高脂膳食(HFD)对小鼠呼吸功能的影响及其线粒体机制。方法将20只4周龄健康雄性C57BL/6小鼠采用简单随机分组分为两组,每组10只,分别以正常膳食(NFD)和HFD饲养16周,每两周称重1次。干预结束后,采用小动物全身容积描记仪测量小鼠呼吸参数,检测血清及膈肌组织脂质指标,将膈肌组织染色后观察膈肌组织形态、肌纤维表型和线粒体超微结构,采用实时荧光定量PCR和免疫印迹检测肌球蛋白重链(MHC)线粒体动力学相关基因和蛋白表达情况。结果NFD和HFD小鼠基线体重分别为(19.17±0.59)和(19.12±0.64)g,差异无统计学意义(P=0.857)。饲养16周后,HFD组小鼠体重为(41.28±2.21)g,高于NFD组[(27.14±0.53)g,P<0.001]。HFD组小鼠吸气峰流速、潮气量和分钟通气量分别为(5.72±0.64)ml/s、(0.23±0.04)ml和(97.49±21.68)ml,均低于NFD组[分别为(7.70±1.52)ml/s、(0.31±0.07)ml和(129.99±28.87)ml](均P<0.05),增强呼吸间歇为1.16±0.07,高于NFD组(0.98±0.09,P<0.001)。HFD组小鼠膈肌甘油三酯含量为(20.43±6.36)mmol/mg,高于NFD组[(11.62±1.78)mmol/mg,P=0.003],膈肌纤维内出现脂滴沉积。HFD组小鼠膈肌MHC⁃Ⅰ型肌纤维占比为13.33%±2.95%,低于NFD组(19.20%±1.23%,P=0.034)。电镜下可见NFD组小鼠膈肌线粒体成行排列,结构清晰;HFD组小鼠膈肌线粒体出现肿胀、嵴断裂和空泡。HFD组小鼠膈肌线粒体融合蛋白2表达水平为0.61±0.16,低于NFD组(1.28±0.03,P<0.001);线粒体动力相关蛋白1和线粒体分裂蛋白1表达水平分别为1.18±0.06和0.91±0.11,均高于NFD组(分别为0.61±0.07和0.60±0.04,均P<0.001)。结论HFD损伤小鼠呼吸功能,其机制与膈肌MHC⁃Ⅰ型肌纤维占比下降及线粒体动力学失衡相关。Objective To investigate the effect of high‐fat diet(HFD)on respiratory function and its mitochondrial mechanism in mice.Methods Twenty 4‐week‐old healthy male C57BL/6 mice were divided by simple random grouping into two groups,10 mice for each group.Mice were raised with normal diet(NFD)and HFD for 16 weeks,respectively,and weighed once every two weeks.At the end of the intervention,respiratory parameters were measured by whole‐body plethysomography,serum and diaphragm tissue lipid species were measured,diaphragm tissue was stained to observe diaphragmmatic morphology,muscle fiber phenotype and mitochondrial ultrastructure.Real‐time fluorescence quantitative PCR and immunoblotting were used to detect myosin heavy chain(MHC)and mitochondrial dynamics‐related genes and protein expression.Results The baseline body weights of NFD and HFD mice were(19.17±0.59)and(19.12±0.64)g,respectively,with no statistically significant differences(P=0.857).After 16 weeks of feeding,the body weight of mice in the HFD group was(41.28±2.21)g,which was higher than NFD group[(27.14±0.53)g,P<0.001].The peak inspiratory flow rate,tidal volume and minute ventilation of mice in the HFD group were(5.72±0.64)ml/s,(0.23±0.04)ml and(97.49±21.68)ml,respectively,which were lower than NFD group[(7.70±1.52)ml/s,(0.31±0.07)ml and(129.99±28.87)ml,respectively,all P values<0.05].Penh value was 1.16±0.07,which was higher than NFD group(0.98±0.09,P<0.001).The diaphragmatic triglyceride content of mice in the HFD group was(20.43±6.36)mmol/mg,which was higher than NFD group[(11.62±1.78)mmol/mg](P=0.003),and lipid droplets were deposited in the diaphragm fibers.The percentage of MHC-Ⅰmuscle fibers in the diaphragm of mice in the HFD group was 13.33%±2.95%,which was lower than NFD group(19.20%±1.23%,P=0.034).The mitochondria of the diaphragm in the NFD group were arranged in rows with clear structures,while in the HFD group showed swelling,cristae breakage and vacuoles.The relative expression level of mitochondrial fusion prot

关 键 词：膳食脂肪类 小鼠 肥胖 呼吸肌 呼吸功能不全 线粒体 肌 

分 类 号：R151[医药卫生—营养与食品卫生学]