小鼠心脏发育中组蛋白乙酰化酶GCN5和PCAF的时空表达特征

SPATIOTEMPORAL EXPRESSION PATTERNS OF HISTONE ACETYLTRANSFERASES GCN5 AND PCAF DURING MOUSE HEART DEVELOPMENT

目的研究组蛋白乙酰化酶氨合成通用控制蛋白5(general control nonderepressible-5 GCN5)和p300/CREB结合蛋白相关因子(p300/CREB binding protein-associated factor PCAF)在小鼠心脏发育过程中的时空表达规律。方法选取胎龄7.5-18d、出生1d和3月成年昆明小鼠正常心脏,利用免疫组织化学法和RT-PCR或Western blot技术半定量检测GCN5和PCAF在小鼠心脏发育过程中的时空表达变化。结果1.GCN5在E7.5-E9.5心脏原基中不表达;E10.5后心内膜垫及室间隔膜部和房室瓣相对强表达,心肌组织弱表达。GCN5 mRNA在E10.5-E11.5出现高峰表达,E12.5-E15.5表达水平下降,E16.5至成年鼠期表达极低。2.PCAF在E7.5-E9.5心脏原基中广泛弱表达;E10.5后心肌膜较强表达,心内膜、房室瓣和小梁网较弱表达,室间隔肌部弱表达,室间隔膜部极弱表达;PCAF蛋白在E10.5已有相对高表达,E11.5达到表达高峰,此后表达逐渐降低,在E13.5-E15.5和E16.5-生后1d仔鼠期出现两个表达平台期,成年鼠期心脏中表达最低。结论GCN5和PCAF在发育心脏中存在不同表达分布和变化规律,表明二者均参与了心脏的发生发育过程,且二者可能与心脏的特定结构发育密切相关。

Objective To study the spatiotemporal expression patterns of histone acetyltransferases general control nonderepressible-5 （GCN5） and p300/CREB binding protein-associated factor （PCAF） during heart development in mice. Methods The normal mouse hearts from E7.5-E18 and neonatal 1 day as well as 3 months were included in this study. Immunohistochemistry was used to observe the temporal and spacial expression of GCN5 and PCAF. RT-PCR technique was used to detect the timed mRNA expressions of GCN5 semi-quantitatively. Western blot was performed to assess the dynamic changes of PCAF proteins semi-quantitatively. Results 1. No expression was detected in heart anlages at E7.5-E9.5; GCN5 was showed weak expressions in myocardium and relatively strong expressions in endocardiac cushions and membranous interventricular septum and atrioventricular valves after E10. 5. GCN5 mRNA showed expression at E10. 5-E11. 5, decreasing expression at E12. 5-E15.5 and extremely low expression after E16.5. 2. Widespread and weak expressions of PCAF in heart anlages were detected at E7.5-E9.5; PCAF showed relatively strong expressions in myocardium, relatively weak expressions in endocardium and atrioventricular valves as well as trabeculae, weak expressions in muscular interventricular septum and extremely weak expressions in membranous interventricular septum after E10. 5. PCAF proteins showed relatively high expression at E10. 5, peak expression at E11. 5 and gradually decreasing expression in the subsequent developmental stages. There are two expression platforms at E13.5-E15.5 and E16.5-postnatal day 1, respectively. At 3 months in the adult mouse heart, the lowest expressions of PCAF were detected. Conclusion There are different distributions and dynamic expression variants of GCN5 and PCAF, indicating that both of them participate in cardiogenesis and may be closely related to Specific structure development of the heart respectively.