Hoxa5基因在先天性膈疝大鼠模型胎肺中的表达

目的 研究Hoxa5基因在先天性膈疝(congenital diaphragmatic hernia,CDH)胎肺中的表达特点以及探讨其在CDH肺发育不良发生机制中的可能作用.方法 采用实时荧光定量PCR(real time quantitative PCR,QPCR)方法检测Hoxa5基因在妊娠第17.5天、19.5天、21.5天的nitrofen诱导CDH大鼠模型胎肺及正常对照大鼠胎肺巾的相对表达量.结果 正常对照组胎肺中Hoxa5 mRNA的表达水平随着胎龄的增加旱下降趋势,其中第21.5天胎肺中Hoxa5 mRNA的表达水平显著下降,与其他二胎龄点相比差异有统计学意义(P＜0.05);CDH组中Hoxa5 mRNA的表达趋势与正常胎肺相似,即随胎龄的增加其表达量下降,其当中第21.5天胎肺中Hoxa5 mRNA的表达水平明显降低,与其他二胎龄点相比差异有统计学意义(P＜0.05).第17.5天与19.5天胎龄CDH组胎肺中Hoxa5 mRNA的表达水平分别与相应对照组相比,差异无统计学意义;而妊娠晚期(第21.5天胎龄)CDH组胎肺中Hoxa5 mRNA的表达水平高于对照组.差异具有统计学意义.结论 正常对照组中第21.5天胎龄时Hoxa5 mRNA的表达水平显著降低,提示Hoxa5 mRNA在孕晚期的低表达是正常肺发育的分子基础之一;而CDH组中第21.5天胎龄时Hoxa5 mRNA的表达水平明显高于对照组,提示Hoxa5在孕晚期CDH胎肺中Hoxa5的高表达可能是CDH肺发育不良形成机制之一.

The Expression of Hoxa5 gene in fetal lungs in rat model of Nitrofen-induced congenital diaphragmatic hernia

Objective To investigate the feature of Hoxa5 gene expression in different development stages of fetal lungs of rats and the role of Hoxa5 in the development of pulmonary hypoplasia with congenital diaphragmatic hernia(CDH).Methods Expression of Hoxa5 mRNA in different development stages(E17.5,E19.5,E21.5)of fetal lungs in rat models of nitrofen-indueed CDH and normal rats was detected by real-time quantitative PCR. Results The expression level of Hoxa5 mRNA kept decreasing during the development of normal lungs at E17.5,E19.5 and E21.5.The Hoxa5 mRNA levels at E21.5 was significantly lower than that of other two gestational ages(P＜0.05).The expression curve of Hoxa5 in the fetal lungs of CDH rats at different development stages was similar to that of normal fetal lungs.There was no significant difference at E17.5 and E19.5 between the CDH group and the control group.The relative quantities of Hoxa5 mRNA in the CDH group was significantly higher than that of the control at E2 1.5(P＜0.05).Conclusions The expression level of Hoxa5 mRNA in normal fetal lungs decreases gradually to a nadir at E21.5,which suggests that lower Hoxa5 mRNA expression at the last stage of gestation may be one of the molecular basis in the morphogenesis of normal lungs.The higher level of Hoxa5 mRNA at E21.5 in CDH group than that in control group suggests that pulmonary hypoplasia in CDH may be caused by increased expression level of Hoxa5 at the last stage of gestation(E21.5).