微小RNA-10a对大鼠心肌缺血再灌注后脑钠肽的影响

Effect of microRNA-10a on expression of brain natriuretic peptide after myocardial ischemia reperfusion in rats

目的 观察大鼠缺血再灌注后组蛋白去乙酰化酶2基因（HDAC2） mRNA、脑钠肽（BNP）的表达,并用微小RNA（miRNA,miR）-10a激动剂（agomirs）对其干预,探讨其与心肌重塑的关系.方法 45只雄性Wistar大鼠随机分为假手术组（A组,n=15）和缺血再灌注组（n=30）,通过结扎左冠状动脉前降支（LAD）制作缺血再灌注模型.模型制作成功24 h后,心肌梗死组再随机分为缺血再灌注对照组（B组,n=15）和miR-10a agomirs干预组（C组,n=15）.miR-10a agomirs干预组予以尾静脉注射miR-10a agomirs（80 mg/kg）,A组和B组给以阴性对照试剂尾静脉注射,每周1次,持续4周.利用实时定量聚合酶链反应（Real-time PCR）法检测缺血再灌注区HDAC2 mRNA的表达,Western blot法测定BNP蛋白的含量.结果 miR-10a agomirs干预4周后,A、B、C3组心肌HDAC2mRNA相对表达量[HDAC2mRNA/甘油醛-3-磷酸脱氢酶（GAPDH） mRNA]分别为6.58±0.23×10-5、14.29±2.16×10-5、10.11±1.55 ×10-5.左心重量指数分别为2.10±0.26、2.61±0.11、2.41±0.12.A组缺血再灌注区心肌中HDAC2 mRNA的表达,BNP蛋白含量,左心重量指数与B、C组比较显著降低,差异有统计学意义（P＜0.05）;B组与C组比较,缺血再灌注区心肌中HDAC2 mRNA的表达,BNP蛋白含量,左心室重量指数显著升高,差异有统计学意义（P＜0.05）.结论 miR-10a可能通过抑制HDAC2 mRNA的表达来抑制BNP的产生,从而改善大鼠缺血再灌注后心肌重塑.

Objective To investigate the effect of microRNA （miRNA,miR）-10a on the expression of brain natriuretic peptide （BNP） in ventricular remodeling after myocardial ischemia reperfusion injury in rats.Methods Forty-five male Wistar rats were randomly divided into sham operation group A （sham operation group,n =15） and myocardial ischemia reperfusion group （n =30）.Rats in myocardial ischemia reperfusion group were inflicted by ligating the left anterior descending coronary of rats.After 24 h,30 survived rats were randomly divided into group B （myocardial ischemia reperfusion group,n =15） and group C （miR-10a group,n =15）.Rats in group C were treated with miR-10a agomirs （80 mg/kg body weight） by tail intravenous injection for 4 weeks,and those in group A and group B were treated with negative control reagents.The expression of histone deacetylase 2 （HDAC2） mRNA was detected by Real-time PCR method respectively.The content of BNP was examined by Western blotting.Results After 4 weeks,the relative expression of HDAC2 mRNA in groups A,B and C was 6.58 ± 0.23 × 10-5,14.29±2.16 × 10-5,and 10.11 ± 1.55 × 10-5 respectively.Left ventricular mass index was 2.10 ± 0.26,2.61 ± 0.11,and 2.41 ±0.12 respectively in groups A,B and C.As compared with group B and group C,the expression of HDAC2 mRNA and BNP in the myocardial ischemia reperfusion zone and left ventricular mass index in group A were significantly increased （P 〈 0.05）.The expression of HDAC2 mRNA and BNP in the myocardial ischemia reperfusion zone and left ventricular mass index in group C were significantly higher than those in group B （P 〈 0.05）.Conelusion miR-10a may improve ventricular remodeling after myocardial ischemia reperfusion in rats via inhibiting the expression of HDAC2 mRNA.