12月9日，Circulation Research（影响因子11.019）在线发表了中国科学院上海生命科学研究院营养科学研究所心脏发育与再生实验室的研究论文：“Endocardium Contributes to Cardiac Fat”。该研究利用遗传谱系示踪技术揭示心脏心内膜细胞形成心肌内脂肪，为部分脂肪过多的心肌病的研究提供了理论基础和新的思路。   

上海南方模式生物的研究人员构建了能够特异性标记胚胎期心内膜细胞的工具小鼠。利用该小鼠，周斌研究员及其课题组对胚胎期心内膜进行示踪,发现大约40%的成体心脏内脂肪来源于胚胎期被标记的心内膜细胞。研究人员利用标记出生后内皮细胞的工具小鼠研究发现，正常发育过程中，小鼠出生后的心内膜不再参与形成心脏内脂肪。在发生心肌梗塞后，成体心内膜细胞也不再参与形成心脏内脂肪细胞。由此可以推测心内膜细胞可能通过内皮间充质化过程形成间充质细胞，间充质细胞继而发育成为脂肪。进一步对心内膜细胞进行了单克隆示踪分析。绝大多数的心内膜细胞只具有单一潜能，即只能分化为冠状血管或脂肪细胞，少数具有双向潜能，既能分化为冠状血管，也能分化为脂肪细胞。此外，研究还探索了心脏内脂肪的其它来源，对心肌细胞和心外膜细胞进行了示踪，发现心外膜细胞也可以参与形成部分心脏内脂肪细胞。 

原文链接：Endocardium Contributes to Cardiac Fat

http://circres.ahajournals.org/content/early/2015/12/09/CIRCRESAHA.115.307202.abstract

Abstract
Rationale: Unraveling the developmental origin of cardiac fat could offer important implications for treatment of cardiovascular disease. The recent identification of the mesothelial source of epicardial fat tissues reveals a heterogeneous origin of adipocytes in the adult heart. However, the developmental origin of adipocytes inside the heart, namely intramyocardial adipocytes, remains largely unknown.
Objective: To trace the developmental origin of intramyocardial adipocytes.
Methods and Results: In this study, we identified that the majority of intramyocardial adipocytes were restricted to myocardial regions in close proximity to the endocardium. Using a genetic lineage tracing model of endocardial cells, we found that Nfatc1+ endocardial cells contributed to a substantial number of intramyocardial adipocytes. Despite the capability of the endocardium to generate coronary vascular endothelial cells surrounding the intramyocardial adipocytes, results from our lineage tracing analyses showed that intramyocardial adipocytes were not derived from coronary vessels. Nevertheless, the endocardium of the postnatal heart did not contribute to intramyocardial adipocytes during homeostasis or after myocardial infarction.
Conclusions: Our in vivo fate-mapping studies demonstrated that the developing endocardium, but not the vascular endothelial cells, gives rise to intramyocardial adipocytes in the adult heart.