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目的探讨小鼠胚胎心神经嵴细胞的形成、分布模式及其在心血管系统发育过程中的作用。方法选用抗细胞视黄酸结合蛋白1(CRABP1)、抗α-平滑肌肌动蛋白(α-SMA)、抗心肌肌球蛋白重链(MHC)、抗胰岛因子1(Isl-1)抗体,对45只胚龄8～12d小鼠胚胎连续切片进行免疫组织化学染色。结果胚龄8d,CRABP1在神经褶的外胚层未见阳性表达。胚龄8.5～9d,在心管与鳃弓水平,神经褶开始出现CRABP1阳性细胞,且有部分细胞从神经褶背侧分离进入邻近间充质。胚龄10d,神经管两侧间充质内的CRABP1阳性细胞迁移至鳃弓、弓动脉壁内皮周围以及流出道心胶质内。胚龄11～12d,弓动脉内皮周围、流出道心内膜垫内CRABP1表达明显下降,但弓动脉管壁α-SMA阳性平滑肌细胞数量增加。主肺动脉隔及其分隔形成的升主动脉和肺动脉干管壁内均可见Isl-1阳性细胞,但未见CRABP1表达。结论小鼠胚胎CRABP1阳性神经嵴细胞形成的时间窗限定在胚龄8.5～9d。胚龄10d后,CRABP1阳性神经嵴细胞经过迁移,参与弓动脉中膜平滑肌和流出道心内膜垫的形成。CRABP1不能用于标记迁移后的神经嵴细胞。
Objective To investigate the formation and distribution patterns of mouse embryonic neural crest cells and their roles in the development of cardiovascular system. Methods Anti-CRABP1, α-SMA, MHC, and Isl-1 were used in this study. 45 embryos of 8 ~ 12d mouse embryos serial sections for immunohistochemical staining. Results There was no positive expression of CRABP1 in the ectoderm of nerve fold on the 8th day after embryo implantation. The embryo age ranged from 8.5 to 9 days. CRABP1 positive cells began to appear in the nerve plexus at the level of the cardiac tube and gill arch, and some cells separated from the dorsal side of the nerve fold into the adjacent mesenchyme. After 10 days of embryo implantation, CRABP1 positive cells within the mesenchyme of neural tube migrated to the gill arch, the periphery of the artery wall of the arch and the outflow tract glia. The number of α-SMA positive smooth muscle cells in the artery wall of the aortic arch increased after embryo age from 11 to 12 days, and the expression of CRABP1 in the endocardial cushion of the outflow tract decreased obviously. Isl-1 positive cells were seen in the main pulmonary artery septum and the ascending aorta and pulmonary artery wall, but no CRABP1 expression. Conclusion The time window of formation of CRABP1 positive neural crest cells in mouse embryos is limited to 8.5-9 days embryo age. After 10 days of embryonic age, the CRABP1 positive neural crest cells migrated and participated in the formation of medial malleolus in the middle cerebral artery and outflow tract. CRABP1 can not be used to mark migratory neural crest cells.