神经嵴细胞和胰岛因子1阳性细胞与小鼠胚胎心流出道发育的关系

目的 探讨迁移中的细胞视黄酸结合蛋白1(CRABP1)阳性神经嵴细胞、胰岛因子1(ISL-1)、阳性心肌前体细胞与小鼠胚胎心流出道发育的关系.方法 36只胚龄8.5～13d小鼠胚胎心连续石蜡切片,选用抗α-平滑肌肌动蛋白(α-SMA)、抗心肌肌球蛋白重链(MHC)、抗转录因子ISL-1、抗CRABP1和抗磷酸化组蛋白H3(PHH3)抗体,进行免疫组织化学及免疫荧光染色.结果 胚龄8.5～10d,ISL-1阳性心肌前体细胞相继出现在心背系膜、原始咽两侧、头面部、鳃弓核心间充质和心包腔背侧壁间充质,构成心管流出道发育的第二生心区.胚龄11～13d,ISL-1阳性细胞在咽前方聚集,形成特征性锥体形结构,并向升主动脉、肺动脉干及主肺动脉隔延伸.胚龄9d前,神经嵴细胞散在分布于ISL-1阳性细胞之间,流出道远侧端可见少量CRABP1和ISL-1双阳性细胞.胚龄10d,CRABP1阳性神经嵴细胞分布在ISL-1阳性鳃弓核心间充质周围.随着发育,弓动脉等处的神经嵴细胞逐渐失去CRABP1表达,开始表达α-SMA.结论 ISL-1阳性第二生心区是动态结构,胚龄8.5～10d时,在神经嵴细胞配合下,向心管动脉端添加心肌细胞;胚龄11d后,开始向平滑肌方向分化,参与升主动脉、肺动脉干和主肺动脉隔的发育.

Association of neural crest cells and ISL-1 positive cells with the development of the outflow tract of the mouse embryonic heart

P>Objective To explore the relationship between migrating neural crest cells expressing cellular retinoic acid binding protein 1(CRABP1) and islet 1（ISL-1）positive cardiac progenitor cells and the development of the outflow tract (OFT) of the mouse embryonic heart. Methods Serial sections of thirty-six mouse embryonic hearts from embryonic 8.5 days (E8.5d) to E13d were stained immunohistochemically or immunofluorescently with antibodies against α-smooth muscle actin (α-SMA), myosin heavy chain (MHC), ISL-1, CRABP1 and phosphorylated histone H3 (PHH3). Results From E8.5d to E10d, ISL-1 positive cardiac progenitor cells were sequentially detected in the mesenchyme of the dorsal mesocardium, the mesenchyme surrounding the primary pharynx, the craniofacial mesenchyme and core mesenchyme in the branchial arches as well as the splanchnic mesoderm dorsal to the pericardial cavity that constituted second heart field (SHF) for the development of OFT of heart tube. From E11d to E13d, ISL-1 positive cells ventral to the pharynx formed a cone-shaped structure from which ISL-1 positive cells extended towards the developing intrapericardial aorta, pulmonary trunk and aorto-pulmonary septum (AP septum). CRABP1 positive neural crest cells were interspersed among the ISL-1 positive cells at early stages. A few CRABP1 and ISL-1 double-positive cells were found at the distal pole of the OFT. At E10d, CRABP1 positive cells were uniquely distributed surrounding the ISL-1 positive core mesenchyme in branchial arches. Thereafter, the gradual disappearance of CRABP1 expression in the wall of aortic arch and other regions was followed by expression of α-SMA. Conclusion The ISL-1 positive SHF is a dynamic structure where myocardial cells are gradually added to the arterial pole of the heart tube under the cooperation of neural crest cells during E8.d-10d.After E11d, SHF is involved in the development of the smooth muscle cells in the wall