心脏α肌动蛋白基因在胚胎心脏发育中的时空表达  

Spatial expression of cardiac alpha-actin during heart development in embryos

作　　者：刘芳[1] 陈树宝[1] 刘晓青[2] 张文竹[3] 

机构地区：[1]上海第二医科大学附属新华医院儿内科,200092 [2]上海第二医科大学附属新华医院儿研所,200092 [3]上海第二医科大学附属新华医院病理科,200092

出　　处：《中华儿科杂志》2005年第10期772-776,共5页Chinese Journal of Pediatrics

基　　金：上海市科学技术发展基金(01JC14024)

摘　　要：目的了解心脏α肌动蛋白(cardiac alpha-actin, CAA)基因在胚胎心脏发育过程中的时空表达规律,探讨其与心脏畸形发生的关系.方法用电刺激方法制备鸡胚心脏畸形模型.用实时荧光定量PCR方法检测胚胎发育不同阶段CAA基因表达量的动态变化;用免疫组化方法检测CAA蛋白在胚胎不同发育时期表达部位的变化.结果 (1)CAA基因在胚胎发育早期即开始表达,以后表达量逐渐增加至稳定.CAA主要局限在心脏部位表达,并随着心肌结构的发育成熟表达逐步增强;在肝脏、脑、胃等器官中不表达或微量表达.(2)心脏神经嵴被破坏的实验组胚胎在胚龄第2～7天,CAA基因相对表达量明显低于正常对照组胚胎相对应时期(P= 0.013).实验组心脏组织在第7、9、15天时CAA基因表达量也明显低于正常对照组(P=0.029).结论 CAA基因与心脏发育密切相关.CAA基因表达受到心脏神经嵴细胞调控,剔除心脏神经嵴后其表达减少,影响了心肌细胞的成熟和分化,可能是导致心脏畸形发生的一个重要因素.Objective Conotruncal defects （CTD） is a common type of cyanotic congenital heart defects. It was shown that CTD might be produced by ablation of cardiac neural crest during early stage embryos in experimental studies. There were many kinds of genes involved and cardiac alpha-actin （CAA） was one of them. The purpose of this study was to investigate the spatial expression of CAA gene during embryonic heart development, and to explore its role in the pathogenesis of congenital heart defects. Methods Experimental chicken embryos were subjected to cardiac neural crest ablation by using electric stimulation at 36 - 40 hr incubation stage. The embryos and organs of experimental and normal control groups during different developing periods were taken out, RNA was extracted by Trizol, and then reverse transcription was done. The dynamic changes of CAA mRNA expression at different development stages of embryos were assayed by fluorescent real-time PCR. The embryos and tissues at different stages were taken out, and paraffin sections were made. The localizations of CAA antibody expression in the developmental embryos were detected by immunohistochemical analysis （peroxidase-DAB coloration）. Results （1） The expression of CAA gene was detected at early embryo development, and increased subsequently to a stable level. Its expression was mainly limited to heart site, and could be increased along with the maturation of the cardiac muscle. There was no expression or little trace expression in liver, brain, and stomach. （2） There was a significantly low level of CAA gene expression on days 2-7 of chicken embryos whose cardiac neural crest were ablated in comparison with normal controls （P =0. 013）. The level of CAA gene expression was also down-regulated on days 7, 9 and 15 of embryonic cardiac tissues （ P = 0. 029 ）. Conclusion CAA gene is closely associated with heart development, its expression was adjusted by cardiac neural crest, and its dysfunction may be an important factor leading to congenital

关 键 词：肌动蛋白类 胎儿心脏 胚胎和胎儿发育 动脉干 

分 类 号：R346[医药卫生—基础医学]