近日，国际著名杂志Circulation Research在线报道了胚胎干细胞来源的exosome可以促进心梗后修复。
结果详细步骤：
第一步：
1、首先鉴定mES（鼠胚胎干细胞）可以分泌exosome。电镜、Nano以及western。exosome提取采用超离方法，然后用生理盐水重悬备用。
2、证实exosome具有功能。可以减缓H9C2细胞对缺氧的死亡；可以减缓胚胎成纤维细胞对H2O2的死亡；可以增加HUVEC的成管。
第二步：
1、行MI手术，心梗边缘区注射exosome，4周后心超、心梗面积等各项指标均明显改善。
2、组织切片的免疫组化等检查，证实exosome可以促进血管新生（毛细血管密度）和心肌细胞增殖。
第三步：
Exosome促进心肌前体细胞的存活及增殖。
第四步：
基因芯片证实exosome中含有差异表达的miRNA，聚焦在miRNA290.然后证实miRNA290的确有作用。最后略带一点miR294的机制，AKT磷酸化。
原文来源：Khan M, Nickoloff E, Abramova T et.al. Embryonic stem cell-derived exosomes promote endogenous repair mechanisms and enhance cardiac function following myocardial infarction.Circ Res. 2015 Jun 19;117(1):52-64.
RATIONALE: Embryonic stem cells (ESCs) hold great promise for cardiac regeneration but are susceptible to various concerns. Recently, salutary effects of stem cells have been connected to exosome secretion. ESCs have the ability to produce exosomes however their effect in the context of the heart is unknown.
OBJECTIVE: Determine the effect of ESC-derived exosome for the repair of ischemic myocardium and whether c-kit+ CPCs function can be enhanced with ESC exosomes Methods and Results: This study demonstrates that mouse ESC derived exosomes (mES Ex) possess ability to augment function in infarcted hearts. mES Ex enhanced neovascularization, cardiomyocyte survival and reduced fibrosis post infarctionconsistent with resurgence of cardiac proliferative response. Importantly, mES Ex augmented cardiac progenitor cell (CPC) survival, proliferation and cardiac commitment concurrent with increased c-kit+ CPCs in vivo 8 weeks after in vivo transfer along with formation of bonafide new cardiomyocytes in the ischemic heart. miRNA array revealed significant enrichment of miR290-295 cluster and particularly miR-294 in ESC exosomes. The underlying basis for the beneficial effect of mES Ex was tied to delivery of ESC specific miR-294 to CPCs promoting increased survival, cell cycle progression and proliferation.
CONCLUSIONS: mES Ex provide a novel cell free system that utilizes the immense regenerative power of ES cells while avoiding the risks associated with direct ES or ES derived cell transplantation and risk of teratomas. ESC exosomes possess cardiac regeneration ability and modulate both cardiomyocyte and CPC based repair programs in the heart.
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