FSTL1在骨髓间充质干细胞保护大鼠心肌缺血再灌注损伤中的作用

Follistatin-like 1-engineered mesenchymal stem cells prevent myocardial ischemic reperfusion injury

目的 研究卵泡抑素样蛋白1（FSTL1）在骨髓间充质干细胞（BM-MSCs）保护心肌缺血/再灌注损伤中的作用.方法 全骨髓贴壁法培养BM-MSCs.构建大鼠心肌缺血再灌注损伤模型,60只Wistar大鼠随机分为4组（每组15只）：心肌缺血再灌注损伤模型假手术组,心肌缺血再灌注模型（IRI）组,心肌缺血再灌注模型注射正常BM-MSCs细胞（IRI＋ MSC）组,心肌缺血再灌注模型注射敲低FSTL1的BM-MSCs细胞（IRI＋ MSC FSTL1 siRNA）组.分析大鼠生存时间,Western印迹法检测大鼠心肌组织FSTL1表达情况.术后7d计算大鼠心肌梗死面积,HE染色检测心肌病理变化,脱氧核糖核苷酸末端转移酶介导的缺口末端标记法（TUNEL）检测细胞凋亡,同时酶联免疫吸附法（ELISA）检测各组血清乳酸脱氢酶（LDH）、磷酸肌酸激酶（CK）、心肌组织丙二醛（MDA）和超氧化物歧化酶（SOD）水平.结果 相较IRI组,IRI＋ MSC组大鼠生存率及存活时间均显著延长,同时外周血及心脏组织中FSTL1蛋白表达明显增高;相较假手术组,IRI组大鼠心肌细胞凋亡率[（29.8±4.5）％比（1.4±0.1）％,P＜0.05]、病理损伤及心肌梗死面积（24.48±4.27比0,P＜0.05）均明显增加,而IRI＋ MSC组大鼠心肌细胞凋亡[（4.2±0.3）％比（29.8±4.5）％,P＜0.05]、病理损伤情况有明显改善,心肌梗死面积也较IRI组大鼠减少（15.12±3.82比24.48±4.27,P＜0.01）,LDH、MDA及CK表达降低,SOD表达增加（P＜0.05）;但是当移植敲低了FSTL1的BM-MSCs后心肌保护作用明显降低（P＜0.05）.结论 间充质干细胞可能通过分泌FSTL1从而减少大鼠心肌梗死面积,进而起到心肌保护的作用.

Objective To investigate the role of follistatin-like protein 1 （FSTL1） on bone marrow mesenchymal stem cells （BM-MSCs）-mediated cardioprotection during myocardial ischemia/reperfusion injury.Methods Rat bone marrow mesenchymal stem cells were isolated by whole bone marrow adherence method in vitro.A total of 60 Wistar rats were randomly divided into 4 groups：control group,ischemic / reperfusion injury （IRI） group,ischemia/reperfusion injury group treated with natural BM-MSCs （IRI ＋ MSC group）,ischemia/reperfusion injury group treated with BM-MSCs which did not contain FSTL1 （IRI ＋ MSC FSTL1 siRNA group）.Survival analysis was used to analyze survival time of rats,besides,expression of FSTL1 was detected by Western blotting.Myocardial pathological changes were detected by Hematoxylin and Eosin （HE） staining.Terminal-deoxynucleoitidyl transferase mediated nick end labeling （TUNEL） and enzyme-linked immunosorbent assay （ELISA） were used to determine the associated biomarkers and apoptosis 7 days after operation.Results Compared with IRI group,rats in IRI ＋ MSC group had a higher survival rate and lived longer.Meanwhile,IRI ＋ MSC group had higher FSTL1 expression in blood and myocardial tissues than IRI group.Control group showed significantly lower apoptosis rate of myocardial cells [（1.4 ± 0.1） % vs （29.8 ± 4.5） %,P 〈 0.05],less histological changes and infarction areas （0 vs 24.48 ± 4.27,P 〈 0.05） than IRI group.Compared with IRI group,IRI ＋ MSC group had an improvement of apoptosis rate [（4.2 ± 0.3） % vs （29.8 ± 4.5） %,P 〈 0.05],less histological injury and infarction areas （15.12 ± 3.82 vs 24.48 ± 4.27,P 〈 0.01）.IRI ＋ MSC group had lower expression of LDH,MDA,CK and higher expression of SOD than IRI group （P 〈 0.05）.However,IRI ＋ MSC FSTL1 siRNA group showed weaker protection of myocardial cells than IRI ＋ MSC group after knockdown of FSTL1 （P 〈 0.05）.Conclusion FSTL1,which was secreted by BM-MSCs,plays a protective role in myocardial IRI.