Notch2信号参与调控小鼠胚胎心脏主动脉与肺动脉瓣膜的发育  

Notch2 contributes to the development of aortic and pulmonary valves in mouse embryonic heart

作　　者：王佳佳 谢建山 李海荣[1] 景宜馨[1] 杨艳萍[1] Wang Jiajia;Xie Jianshan;Li Hairong;Jing Yixin;Yang Yanping(Department of Histology and Embryology,Shanxi Medical University,Taiyuan 030001,Shanxi Province,China)

机构地区：[1]山西医科大学组织胚胎学教研室,山西省太原市030001

出　　处：《中国组织工程研究》2023年第14期2176-2181,共6页Chinese Journal of Tissue Engineering Research

基　　金：国家自然科学基金(31200899),项目负责人:杨艳萍。

摘　　要：背景:先天性心脏畸形常表现为动脉瓣膜发育异常,其中以主动脉瓣二叶式畸形最常见,但目前对于胚胎主、肺动脉瓣膜的具体发育过程有待阐明。目的:探讨小鼠胚胎心脏流出道的分隔与主、肺动脉瓣膜原基形成及其重塑过程。方法:2月龄SPF级健康ICR小鼠雌鼠16只、雄鼠10只,于每日晚18:00以雌雄2∶1的比例进行合笼,次日6:00发现阴栓者记为妊娠0.5 d。选取胚龄9.5-15 d的小鼠胚胎石蜡包埋连续切片,免疫组织化学染色观察胚龄9.5-15 d的小鼠胚胎心脏Isl1、Nkx2.5、肌球蛋白重链、Ap2α、Sox9、α-平滑肌肌动蛋白、Snail、Jag1、Notch2、Alk3和p-Smad1/5/8的蛋白表达;心脏的三维重建观察流出道心内膜垫和插入垫的变化以及瓣膜的形态。结果与结论:(1)胚龄9.5-10.5 d小鼠胚胎,流出道内皮细胞经过上皮-间充质转化形成心胶质内的间充质细胞,参与形成流出道心内膜垫;胚龄11-11.5 d,咽前Isl1阳性细胞延伸入流出道壁形成插入垫,此过程未发生上皮-间充质转化;Notch2信号参与流出道心内膜垫形成过程但未参与插入垫的形成;(2)胚龄12.5 d,流出道心内膜垫远端融合形成主动脉的左、右冠瓣和肺动脉的左、右半月瓣原基,插入垫形成主动脉的无冠瓣和肺动脉的前半月瓣原基,Notch2信号表达于所有瓣膜原基;胚龄13-15 d,动脉瓣膜原基完成重塑形成细长的瓣膜,Notch2信号在瓣膜的表达逐渐变弱;(3)研究结果提示,流出道插入垫内的间充质细胞来自第二生心区Isl1阳性细胞;Notch2信号可能未参与插入垫的形成,但可能参与流出道心内膜垫的形成以及主、肺动脉瓣膜原基的重塑。BACKGROUND:Abnormalities of the arterial valve leaflets explain part of congenital heart malformations.Among of these,bicuspid aortic valve are the commonest congenital malfo rmations in humans.However,the development process of the aortic and pulmonary valves in embryonic heart remains to be further elucidated.OBJECTIVE:To observe the septation of outflow tra ct and the formation and remodeling of aortic and pulmonary valve anlagen in mouse embryonic heart.METHODS:Healthy ICR mice of 2 months old,SPF grade including 16 females and 10 males,were caged at 18:00 eve ry night at a ratio of 2:1 between females and males.The mice which found vaginal plugs at 6:00 the next day were recorded to be at 0.5 days of pregnancy.The mouse embryos at 9.5-15 days of embryonic age were selected for preparing paraffin-embedded serial sections.Immunohistochemical staining was used to observe the protein expression of lsl1,N kx2.5,myosin heavy chain,Ap2 a,Sox9,a-smooth muscle actin,Snail,Jag1,Notch2,Alk3,and p-Smad1/5/8 in the mouse embryonic heart at 9.5-15 days of embryonic age.Three-dimensional reconstruction of the heart was performed to observe changes in the outflow tract endocardial cushion and inte rcalated cushions as well as valve morphology.RESULTS AND CONCLUSION:During embryonic days 9.5-15,endothelial cells in the outflow tra ct were transfo rmed into mesenchymal cells in the cardiac jelly through epithelial-mesenchymal transfo rmation,which participated in the formation of endocardial cushion in the outflow tra ct.From embryonic days11 to 11.5,lsl1 positive cells in the pharyngeal mesenchyme extended into the outflow tract wall to form intercalated cushions,and epithelial-mesenchymal transfo rmation was not observed during this process.N otch2 signal was involved in the formation of endocardial cushion in the outflow tra ct,but not in the formation of intercalated cushions.At embryonic day 12.5,the distal poles of the bilateral endocardial cushions of the outflow tra ct were fused to form the left and right coronary va

关 键 词：小鼠胚胎 动脉瓣膜 流出道心内膜垫 上皮-间充质转化 NOTCH2 第二生心区 心脏 

分 类 号：R446[医药卫生—诊断学] R496[医药卫生—临床医学] R318