Pax-8基因在心脏发育中蛋白表达下调

目的：观察Pax-8基因在ALK3基因敲除小鼠心脏中的蛋白表达情况,探讨Pax-8基因在心脏发育中的作用。方法：基因芯片（microarray）和定量逆转录-聚合酶链反应测定ALK3基因的下游基因,免疫组化法检测13.5 d小鼠胚胎心脏特异性ALK3基因敲除小鼠胚胎中Pax-8蛋白的表达,连续病理切片及HE染色观察刚出生的Pax-8基因敲除小鼠的心脏形态。结果：在心脏特异的ALK3基因敲除小鼠中,转录因子Pax-8基因mRNA的表达水平上被下调7.1倍。免疫组化结果显示：13.5 d小鼠胚胎心脏特异性ALK3基因敲除的纯合子小鼠Pax-8基因在蛋白水平与杂合子相比也明显下调。Pax-8基因敲除小鼠纯合子有明显的室间隔和左心室肥厚,心脏呈球形。结论：Pax-8基因是ALK3基因的下游基因,与心脏发育有密切关系。

Down-regulated protein expression level of Pax-8 gene during heart development in mice

Objective： To investigate the level of Pax-8 protein expression in the conditional ALK3 kockout mice heart and study the role of Pax-8 gene in the cardiac development. Methods： The microarray and real time quantitative RT-PCR were used to investigate the downstream genes of ALK3. Immunohistochemical technology was used to detect the level of Pax-8 protein expression in the 13.5 d heart derived from a-MHC Cre＋/-,ALK3 F/- and a-MHC Cre＋/-, ALK3 F/＋ mice. To study the contribution of Pax-8 gene in the cardiac development,the heart derived from pax-8 kockout mice was overviewed using consecutive pathological section and HE staining method. Results：The level of Pax-8 mRNA expression was down-regulated 7.1 fold in the embryonic heart （11.5 days） of a-MHC Cre＋/-, ALK3 F/-. The level of Pax-8 protein expression was also remarkably down-regulated in the embryonic heart （13.5 days） of a-MHC Cre＋/-,ALK3 F/-. The heart of pax-8 KO-/-mice became spheroidal,the left ventricle enlarged, left ventricular wall and interventricular septum thickened, papillary muscles in the left ventricle enlarged. Conclusion： Pax-8 gene is the cardiac-specific ALK3 downstream gene. Pax-8 may play important roles in the cardiac development.