摘要
目的探讨微小RNA-499(miR-499)调节α型和β型肌球蛋白重链(α-MHC、β-MHC)基因轴在脓毒症心功能障碍(SMD)中的作用机制及意义。方法将60只健康成年雄性SD大鼠按随机数字法分为磷酸盐缓冲液(PBS)对照组(PBS组)、脂多糖(LPS)致SMD模型组(LPS组)、miR-499激动剂预处理组(agomir+LPS组)和miR-499抑制剂预处理组(antagomir+LPS组),每组15只。采用腹腔注射LPS 10 mg/kg制备SMD大鼠模型;PBS组腹腔注射等量PBS。两个预处理组分别于制模前连续3 d经尾静脉注射agomir 30 mg/kg或antagomir 80 mg/kg,每日1次;PBS组和LPS组不给予预处理。注射LPS 5 h后检测超声心动图,并记录相关指标;在注射LPS 6 h后取左心房血和心肌组织,采用实时定量聚合酶链反应(qPCR)检测血浆和心肌组织中miR-499的表达量;采用蛋白质免疫印迹试验(Western blotting)检测心肌组织中α-MHC、β-MHC的蛋白表达;采用电化学发光仪测定血浆心力衰竭标志物N末端脑钠肽前体(NT-proBNP)水平。结果与PBS组比较,LPS刺激后大鼠出现精神萎靡,血浆和心肌组织中miR-499表达下调,且心肌组织中α-MHC表达显著下调、β-MHC表达显著上调,超声心动图结果显示左室射血分数(LVEF)、左室短轴缩短率(LVFS)、心排血量(CO)、每搏量(SV)和心率(HR)分别下降了49.1%、59.2%、48.8%、39.4%、15.9%,且血浆NT-proBNP水平显著升高,表明LPS能诱导大鼠心功能障碍。与LPS组相比,给予agomir预处理过表达miR-499后,超声心动图显示大鼠心功能改善,表现为LVEF、LVFS显著升高〔LVEF:0.662±0.020比0.323±0.024,LVFS:(36.16±1.43)%比(20.20±1.32)%,均P<0.01〕;同时大鼠心肌组织中β-MHC/α-MHC失调被逆转,β-MHC蛋白表达显著下调(β-MHC/GAPDH:0.74±0.04比2.97±0.34,P<0.01),α-MHC的蛋白表达显著上调(α-MHC/GAPDH:1.59±0.05比0.74±0.14,P<0.01),且血浆NT-proBNP水平明显下降(ng/L:114.49±6.85比334.13±4.36,P<0.01)。而给予antagomir预处理抑制miR-499表达后,超声心
Objective To investigate the role and mechanism of microRNA-499(miR-499)regulatingα-myosin heavy chain(α-MHC)and β-myosin heavy chain(β-MHC)gene axis in septic myocardial dysfunction(SMD)and its significance.Methods Sixty healthy adult male Sprague-Dawley(SD)rats were divided into phosphate buffered saline(PBS)control group(PBS group),lipopolysaccharide(LPS)induced SMD model group(LPS group),miR-499 agonist pretreatment group(agomir+LPS group),and miR-499 inhibitor pretreatment group(antagomir+LPS group)by random number table,with 15 rats in each group.SMD rat model was reproduced by intraperitoneal injection of LPS 10 mg/kg.The PBS group was intraperitoneally injected with the same amount of PBS.The two pretreatment groups were injected with agomir 30 mg/kg or antagomir 80 mg/kg through the caudal vein for 3 days,once a day.PBS group and LPS group were not pretreated.Echocardiography was detected 5 hours after LPS injection,and relevant indexes were recorded.The expression of miR-499 in plasma and myocardial tissue was detected by real-time quantitative polymerase chain reaction(qPCR).Western blotting was used to detect the protein expressions of α-MHC and β-MHC in myocardial tissue.Plasma N-terminal pro-brain natriuretic peptide(NT-proBNP),a marker of heart failure,was measured by electrochemiluminescence.Results Compared with the PBS group,the rats in LPS group were depressed.Additionally,LPS down-regulated the level of miR-499 in plasma and myocardial tissue,decreasedα-MHC expression in myocardial tissue and up-regulated the expression ofβ-MHC.Echocardiography showed that left ventricular ejection fraction(LVEF),left ventricle fractional shortening(LVFS),cardiac output(CO),stroke volume(SV)and heart rate(HR)decreased by 49.1%,59.2%,48.8%,39.4%and 15.9%,respectively,and the level of plasma NT-proBNP increased significantly in LPS group,indicating that LPS could induce cardiac dysfunction in rats.Compared with the LPS group,after pretreatment with agomir to overexpress the miR-499,LVEF and LVFS were sig
作者
杨永丽
李泽山
叶红兵
刘海珍
Yang Yongli;Li Zeshan;Ye Hongbing;Liu Haizhen(Department of Critical Care Medicine,Hubei NO.3 People's Hospital of Jianghan University,Wuhan 430033,Hubei,China;Department of Internal Medicine,Jiayu Hospital of Traditional Chinese Medicine(Jiayu Branch of Hubei NO.3 People's Hospital of Jianghan University),Jiayu 437200,Hubei,China;Department of Cardiovascular Medicine,Hubei NO.3 People's Hospital of Jianghan University,Wuhan 430033,Hubei,China)
出处
《中华危重病急救医学》
CAS
CSCD
北大核心
2022年第1期54-58,共5页
Chinese Critical Care Medicine
基金
湖北省卫生健康科研基金资助项目(WJ2021F130)。
