神经嵴细胞和胰岛因子-1阳性细胞与小鼠胚胎心动脉端的发育

Distribution patterns of neural crest cells and ISL-1 positive cells during the development of arterial pole of the mouse embryonic heart

目的：探讨神经嵴细胞和胰岛因子-1（ISL-1）阳性细胞与小鼠胚胎心动脉端发育的关系。方法：胚龄8～12d小鼠胚胎心连续石蜡切片，进行免疫组织化学检测。结果：α-平滑肌肌动蛋白（α-SMA）、心肌肌球蛋白重链（MHC）、转录因子ISL-1、激活蛋白-2α（AP-2α）的表达胚龄8d，AP-2α阳性神经嵴细胞主要表达于神经褶外胚层。胚龄9～11d，AP-2α阳性神经嵴细胞在前肠两侧沿弓动脉逐渐迁移至流出道头端心内膜垫，并形成主肺动脉隔雏形。胚龄8～10d，ISL-1阳性细胞分布于前肠及神经沟两侧中胚层，构成第2生心区，向流出道添加心肌细胞。胚龄10-11d，ISL-1阳性细胞在前肠腹侧正中间充质中聚集、与AP-2α阳性细胞共同参与主肺动脉隔形成。心包腔背侧脏壁中胚层及鳃弓核心间充质的ISL-1阳性细胞与流出道u-SMA或MHC阳性心肌相延续。胚龄12d，主肺动脉隔及流出道心内膜垫失去AP-2α及ISL-1阳性表达，转变为u-SMA阳性表达结构。结论：AP-2α阳性心神经嵴细胞和第2生心区来源的ISL-1阳性心前体细胞共同参与了小鼠心动脉端的形态发生。胚龄8～10d，ISL-1阳性细胞分化为流出道心肌细胞。胚龄10～12d，ISL-1阳性心前体细胞与AP-2α阳性细胞共同参与了主肺动脉隔的形成和流出道的分隔。

Objective： To investigate the distribution patterns of neural crest cells and ISL-1 positive cells during the development of arterial pole of mouse embryonic heart. Methods： Serial sections of mouse embryos from embryonic day（ED） 8 to El） 12 were stained immunohistochemically with antibodies against α-SMA, MHC, AP-2a and ISL-1. Results： At ED 8, AP-2a positive crest cells were mainly distributed in the ectoderm of neural fold. At ED 9-11, migration of AP-2a positive crest cells was detected along the aortic arch arteries towards the endocardial cushion and the arterial pole of the outflow tract of the embryonic heart to take part in the formation of the aorto-pulmonary septum （AP septum）. At ED 8-ED 10, ISL-1 positive cells were found in the mesoderm on both sides of neural groove to form the second heart field and add cardiocytes to the outflow tract. At ED 10-11, ISL-1 posi- tive cells were found to cooperate with AP-2α positive cells in the mesenchyme ventral to the foregut endoderm to participate in the formation of AP septurr The positive cells of ISL-1 were distributed in the dorsal splanchnic mesoderm of the pericardial cavity and core mesenchyme in the branchial arches were continuous with α-SMA or MHC positive myocardium of the outflow tract. At ED 12, AP septum and endocardial cushion of outflow tract lost the expression of AP-2a and ISL1, and began showing expression of α-SMA. Conclusion： AP-2α positive cardiac neural crest cells, together with 1SL-1 positive cardiac progenitors that come from the second heart field, participate in the morphogenesis of arterial pole of mouse embryonic heart. At ED 8-ED 10, ISL-1 positive cells differentiate into cardiocytes of the outflow tract. At ED 10-ED 12, ISL-1 positive cardiac progenitors and AP-2α positive Cells participate in the formation of AP septum and the separation of outflow tract.