脂肪干细胞对心肌梗死大鼠心肌组织中miR-423-5p及PI3K/AKT通路的影响

Effects of adipose stem cells on miR-423-5p and PI3K/AKT pathways in myocardial tissue of rats with myocardial infarction

目的探讨脂肪干细胞(ADSCs)对心肌梗死模型大鼠心肌组织中miR-423-5p、PI3K、AKT的影响。方法将实验大鼠随机分为对照组、心梗模型组(模型组)、心梗模型+rADSCs组(干预组),每组6只。对照组大鼠麻醉后仅开胸后缝合,模型组、干预组大鼠麻醉后结扎前降支,干预组在缝合前心脏原位注射大鼠脂肪干细胞(10^(6)个细胞/只)。观测并称量各组大鼠心脏质量,用HE染色及Masson染色观察心肌组织病理变化,实时荧光定量PCR检测miR-423-5p、PI3K、AKT的mRNA表达情况,Western blot方法检测AKT、p-AKT、PI3K、p-PI3K的蛋白表达。结果与对照组相比,模型组、干预组大鼠的心脏组织质量显著升高,其中模型组与对照组间差异有统计学意义(P<0.05);病理结果显示模型组大鼠心肌细胞排列紊乱,细胞变性坏死严重,胶原纤维沉淀,可见明显的炎性浸润,干预组的大鼠心肌细胞的坏死情况、炎性浸润、胶原纤维沉淀较模型组明显降低;与对照组相比,模型组大鼠心肌组织中PI3K、AKT、miR-423-5p的mRNA表达水平和p-PI3K、p-AKT的蛋白表达水平显著升高(P<0.05);干预组中以上指标的表达水平较模型组显著降低(P<0.05)。结论大鼠脂肪干细胞可以降低心梗模型大鼠心肌组织损伤和纤维化,改善梗死后的心功能。其内在调控机制可能为分泌miR-423-5p,抑制PI3K、AKT的转录水平和蛋白磷酸化水平,发挥保护和治疗心肌梗死的作用。

Objective To investigate the effects of adipose mesenchymal stem cells on miR-423-5p,PI3K,and AKT in myocardial tissue of myocardial infarction model rats.Methods The rats were randomly divided into 3 group:control group,MI model group(MI),MI+adipose-derived stem cells(MI+rADSCs)intervention group,with 6 rats in each group.After anesthesia,the rats in control group were opening the chest and suture,the rats in MI model group and MI+rADSCs group was ligatured anterior descending branch.10^(6)adipose stem cells(adscs)were injected in rats'heart of the MI+rADSCs group before suture.Heart's weight was measured,and the pathological changes were observed by HE staining and Masson staining.Real-time quantitative PCR was used to detect the mRNA expression of miR-423-5p,PI3K and Akt.Western blot was used to detect the protein expression of Akt,p-AKT,PI3K and p-PI3K.Results Compared with the control group,the cardiac tissue mass of the MI model group and the MI+rADSCs group was significantly increased,and the difference between the MI group and the control group was statistically significant(P<0.05).The pathological results showed that the arangement of myocardial cells was disordered,the degeneration and necrosis of myocardial cells were serious,the collagen fibers were precipitated,and obvious inflammatory infiltration was found in the myocardial cells of the MI group.Compared with the MI group,the myocardial necrosis,inflammatory infiltration and cllagen deposition in the MI+rADSCs group were significantly lower than those.Compared with the control group,the mRNA expression levels of PI3K,AKT,Mir-423-5p and the protein expression levels of p-PI3K,p-AKT in myocardial tissue of the MI group were significantly higher(P<0.05).The expression level of the above indexes in the MI+rADSCs group was significantly lower than that in the MI group(P<0.05).Conclusion Adipose-derived stem cells can reduce myocardial injury and fibrosis,and improve cardiac function after myocardial infarction.The mechanism may be that miR-423-5p can inhibit the transcription and protein phosphorylation of PI3K and Akt,and protect and treat myocardial infarction.