缝隙连接蛋白connexin26基因条件性敲除小鼠血管纹超微形态研究

摘要

目的 观察不同年龄缝隙连接蛋白26(Connexin 26,Cx26)基因条件性敲除小鼠血管纹的超微病理形态学改变,探索Cx26突变的致聋机制.方法 将Cx26 loxP/loxP与foxg1-cre转基因小鼠进行杂交,获得Cx26条件基因敲除小鼠模型(Foxg1-Cre cCx26ko条件性敲除小鼠,简称为cCx26ko小鼠),与野生型小鼠(wild type,WT)进行对比.分离出小鼠耳蜗标本,先制作半薄切片定位,再行超薄切片,采用透射电子显微镜(transmission electron microscope,TEM)观察血管纹细胞的超微病理改变.结果 血管纹各种细胞在早期未见异常;出生后120天(postnatal day 120,P120)起细胞内出现溶酶体增多,P180天见巨大吞噬细胞,P360天见色素颗粒.结论 Connexin 26基因条件性敲除小鼠出生后早期血管纹超微形态基本正常.成年转基因动物的血管纹出现超微病理学改变,推测其与细胞异常代谢和衰老有关,这可能是Cx26突变致聋的病理机制之一.%Objective To observe ultrastructural changes in the stria vascularis in Connexin 26 gene knockout mice of different ages. Methods cCx26ko conditional knockout mice (referred as cCx26ko mice) were generated by crossbreeding of Cx26 loxP/loxP and foxgl-cre transgenic mice. Wild mice served as controls. Cochlear specimens were separated from mice. Semithin sections were made for cochlear location, and then ultrathin sections were prepared. Ultrastruc-tural morphology of stria vascularis were examined under a transmission electron microscope (TEM). Results No abnormal ultrastructural morphology was observed in stria vascularis at early ages. From P120, the number of lysosomes increased. Large macrophages and pigment granules appeared after P180 and P360 respectively. Conclusion Abnormal ultrastructural morphology is present in the stria vascularis in adult cCx26ko mice, which may be related to metabolism disturbance and aging.