心源性Nestin阳性干细胞的分离鉴定与治疗心肌梗死的作用机制研究

Nestin在神经干细胞、骨髓间充质干细胞等多种成体干细胞中特异表达，提示Nestin可能是多系祖细胞的共同标志。申请人利用Nestin-GFP小鼠研究发现，Nestin在心脏组织中表达,并初步证实分选得到的GFP阳性细胞具有增殖分化潜能和修复病损组织的能力，提示Nestin阳性细胞可能为治疗心肌梗死的重要种子细胞,但目前对于其发育起源、增殖分化特性以及修复梗死心肌的机制尚不清楚。本项目拟在前期工作基础上，深入研究心源性Nestin阳性细胞的自我更新与分化潜能，利用RNA-Seq等技术系统描述该细胞的表达谱特征，分析其发育起源；建立小鼠心肌梗死模型，观察Nestin阳性细胞修复梗死心肌的作用，并进而利用体内外模型探讨该细胞是否通过直接分化或旁分泌机制修复损伤心肌。该研究不仅有助于阐明Nestin阳性细胞在心脏损伤修复中的作用，也为进一步利用Nestin阳性细胞进行组织替代治疗提供有力依据。

Nestin is specifically expressed in neural stem cells， mesenchymal stem cells and other adult stem cells.This phenomenon suggests that Nestin may be the common marker of multi-lineage progenitor cells. We previously demonstrated that Nestin is distributed in heart tissue using Nestin-GFP mice，and preliminarily confirmed the GFP-positive cells which sorting from research possess the ability of proliferation and differentiation and also with capacity to repair lesions of organizations. This finding explains that Nestin-positive cells may be the important stem cells in the treatment of myocardial infarction.However， the mechanism of their proliferation，developmental origin，differentiation characteristics，and repairing the infarcted myocardium remain unclear now. The project is proposed on the basis of preliminary work. We will depth study the potential capacity of self-renewal and differentiation of Nestin-positive stem cell， systematic describe the expression profile of the cells by using RNA-Seq technology ， and analysis their origins. Then we will establish experimental model of myocardial infarction in mice，observe the effect of Nestin-positive stem cells to repair infarcted myocardium，and thus make use of the model in vitro and in vivo to investigate whether the cells repair injured myocardium by direct differentiation or paracrine mechanisms.The study not only help to clarify the role of Nestin-positive stem cells in repairing infarcted myocardium，but also provide a strong basis for the further use of the Nestin-positive cells in tissue replacement therapy.