miR-328表达对心肌梗死小鼠心脏损伤的影响及其分子机制

Effect of miR-328 expression on heart injury of myocardial infarction mice and the molecular mechanism

目的观察微小RNA-328(miR-328)对心肌梗死(MI)小鼠心脏损伤的影响,并探讨其可能的分子机制。方法选择C57B/L小鼠125只,随机分为对照组、模型组、空病毒组、miR-328组、antimiR-328组,每组25只。除对照组外均建立MI模型,空病毒组、miR-328组及antimiR-328组分别用微量注射器吸取50μL腺病毒载体溶液、载有miR-328的腺病毒溶液及载有抑制miR-328的腺病毒溶液。各组于处理后24 h、1周、2周,采用实时荧光定量PCR法检测梗死心肌组织miR-328表达。各组于处理后24 h,TTC染色后计算心肌梗死率;于处理后1周,采用经胸超声检查计算左心室射血分数(LVEF),实时荧光定量PCR法和Westernblotting法分别检测L型钙离子通道β亚基(CaV2)mRNA及蛋白表达,并分析梗死心肌组织miR-328与CaV2 mRNA表达的关系。结果梗死心肌组织miR-328表达:处理后24 h、1周,对照组、antimiR-328组<模型组、空病毒组<miR-328组(P均<0.05);处理后2周,anti miR-328组<对照组、模型组、空病毒组<miR-328组(P均<0.05)。心肌梗死率:对照组、antimiR-328组<模型组、空病毒组<miR-328组(P均<0.05)。LVEF、梗死心肌组织CaV2 mRNA及蛋白表达:对照组、antimiR-328组>模型组、空病毒组>miR-328组(P均<0.05)。梗死心肌组织miR-328与CaV2 mRNA相对表达量呈负相关关系(r=-0.775,P<0.05)。结论MI小鼠梗死心肌组织miR-328表达升高,miR-328可加重MI小鼠心肌损伤、导致心功能降低,其机制可能与负性调控CaV2表达有关。

Objective To investigate the effect of microRNA-328(miR-328)on heart injury of myocardial infarc⁃tion(MI)mice and the underlying molecular mechanism.Methods Totally 125 male C57B/L mice were randomly di⁃vided into five groups:sham group,myocardial infarction group(MI group),myocardial infarction+adenovirus vector group(MI+vector group),myocardial infarction+microRNA-328 transfection group(miR-328 group),and myocardial infarction+miR-328 antisense inhibitor group(anti miR-328 group),with 25 mice in each group.MI models were estab⁃lished except for the sham group.The MI+vector group,miR-328 group and anti miR-328 group were treated with 50μL of adenovirus vector solution,adenovirus solution containing miR-328,and adenovirus solution containing anti miR-328.Expression of miR-328 in the myocardial infarction tissues was detected by real-time fluorescent quantitative PCR at 24 h,1 week,2 weeks after treatment.The myocardial infarction rate of mice was calculated after TTC staining at 24 h after treatment.At 1 week after treatment,transthoracic ultrasound was used to calculate the left ventricular ejection fraction(LVEF),real-time fluorescent quantitative PCR and Western blotting were used to detect the mRNA and protein expres⁃sion levels of CaV2.The relationship between miR-328 and CaV2 mRNA expression in myocardial infarction tissue was de⁃tected by Pearson correlation analysis.Results MiR-328 expression in the myocardial infarction tissues was in the fol⁃lowing order:at 24 h and 1 week after treatment,sham group and anti miR-328 group<MI group,MI+vector group<miR-328 group(all P<0.05);at 2 weeks after treatment,anti miR-328 group<sham group,MI group and MI+vector group < miR-328 group(all P<0. 05). The myocardial infarction rate of mice in each group was in the following order: sham group and anti miR-328 group < MI group,MI+ vector group < miR-328 group(all P <0. 05). The LVEF and expres⁃ sion levels of CaV2 mRNA and protein in the myocardial infarction tissues were as follows:sham group and anti miR-328 group > MI group,MI+ vector group >miR-328 group(all P<0. 05). Moreover,a negative correlation was found between miR-328 and CaV2 mRNA expression in the myocardial infarction tissues(r = -0. 775,P<0. 05). Conclusion The ex⁃ pression of miR-328 increases in the infarcted myocardial tissues of mice,and miR-328 aggravates myocardial injury and reduces cardiac function in MI mice;the mechanism may be related to the negative regulation of CaV2 expression.