雪旺细胞移植改善心肌梗死后副交感/交感神经重塑

目的： 对心肌梗死后的心脏进行雪旺细胞（Schwann cells）移植，从而改善心肌梗死的心脏神经的重塑，降低心肌梗死后室性心律失常易感性，以达到雪旺细胞移植治疗心肌梗死后心率失常的目的。方法： 利用结扎Lewis大鼠冠状动脉前降支的方法建立急性大鼠心肌梗死模型，并将心肌梗死的大鼠随机分为细胞移植组（ n=31）和对照组（ n=30）。雪旺细胞取自大鼠坐骨神经，经爬片S100染色鉴定雪旺细胞表面标记物。并将经体外培养扩增后的雪旺细胞（5×106）通过注射的方式移植于心肌梗死周边区，并在细胞移植后的2 周用免疫荧光及免疫组织化学方法检测心肌梗死边缘区副交感、交感神经，动态心电图和程序性电刺激（PES）检测室性心律失常的易感性。 结果： 通过S100染色发现，培养获得的雪旺细胞纯度达到95%以上，在雪旺细胞移植后的2 周，免疫组织化学和免疫荧光结果显示，雪旺细胞移植能够显著改善心肌梗死边缘区副交感/交感神经的比例，并且能够显著降低动态心电图频域检测中低频/高频的比值，同时显著降低了室性心律失常的易感性。结论： 雪旺细胞移植能够有效改善心肌梗死部位副交感/交感神经的比例，从而降低心肌梗死后室性心律失常的发生率。

Remodeling of parasympathetic/sympathetic ratio in the infarcted myocardium after Schwann cell transplantation

Objective: To investigated the feasibility of remodeling nervous system regeneration after myocardial infarction and the efficacy by which it may prevent ventricular arrhythmia following Schwann cells transplantation. Methods: Myocardial infarction was induced by left anterior descending artery ligation in syngenic Lewis rats, then the rats were randomized into cell transplantation group (n=31) and control group (n=30).Schwann cell were isolated from sciatic nerves, and immunohistochemical of S100 was carried out for the identification of Schwann cells. 5×106 Schwann cell were intramyocardially injected into the border zone of infarct region. The density of sympathetic and parasympathetic nerves and growth-associated protein 43 in the infarct region were stained by immunohistochemical method and immunofluorescence at 2 weeks after Schwann cells transplantation. Meanwhile, dynamic electrocardiography and programmed electric stimulation were also performed to detect the susceptibility of ventricular arrhythmias. Results: More than 95% of cells were S-100-positive Schwann cells during the entire culture process. Immunohistochemical and immunofluorescence staining illustrated increases in sympathetic and parasympathetic nerves in both groups. However, Schwann cells transplantation significantly increased the parasympathetic/sympathetic ratio at 2 weeks after cell injection. In addition,the Schwann cells also significantly decreased the low-/high-frequency ratio and susceptibility of programmed electric stimulation-induced ventricular arrhythmia at 2 weeks after cell injection. Conclusion: Transplanted Schwann cells in the infarcted myocardium can alter the ratio of parasympathetic/sympathetic nerve density to normalize irritable myocardium.