大鼠胚胎发育期NBC1 在胰腺的表达与定位

目的:探讨碳酸氢钠协同转运载体(NBC1)在大鼠胰腺胚胎发育期不同阶段核酸、蛋白水平的动态变化以及在腺泡和β细胞的定位表达。方法:采用高密度寡核苷酸芯片对孕12.5 d(E12.5)、E15.5、E18.5、新生和成年胰腺进行基因转录水平分析,用RT-PCR和Western blot分别验证了NBC1核酸和蛋白在E15.5、E18.5、新生和成年时期胰腺中的表达情况,用Double fluorescence immunohistochemistry分析了NBC1在E18.5、新生和成年时期胰腺腺泡和β细胞的定位表达。结果:在大鼠胰腺胚胎发育过程中,NBC1核酸、蛋白在E18.5时特异高表达,新生下降直至成年最低;在腺泡基底侧膜和β细胞膜有强烈的阳性信号,且在成年胰腺中β细胞膜阳性信号较腺泡基底侧膜强。NBC1的表达变化与其功能近似基因的表达趋势相反,而与其协同发挥作用的基因及胰腺特异基因的表达趋势一致。结论:NBC1在胰腺发育过程中不仅与结构形成而且与功能发挥相关。

Expression and Localization of NBC1 during Rat Embryonic PancreaticDevelopment

Objective: To investigate the differential expression of electrogenic Na+/HCO3-cotransporter NBC1(SLC4A4) and its localization on the acinar and βcells in the rat embryonic pancreas of different developmental stages.Methods: The expression patterns of embryonic day 12.5(E12.5),E15.5,E18.5,newborn and adult rat were detected using the GeneChip RAE 230A.The expression level of NBC1 at embryonic day E15.5,E18.5,newborn and adult rat was detected by RT-PCR and Western blot analysis.The localization of NBC1 on acinar and βcells at E18.5,newborn and adult rat was identified by Double fluorescence immunohistochemistry.Results: During rat embryonic pancreas development,the mRNA and protein of NBC1 had its highest expression level at E18.5,then it decreased dramatically at adult rat which had the lowest expression.Strong positive signal of NBC1 protein was observed in the basolateral plasma membrane of acinar cells and the plasma membrane of βcells although positive staining was more weaker at acinar cells and more stronger at βcells in the adult rat.The expression tendency of adult rat specific genes and the genes cooperated with NBC1 were consistent with the expression profile of NBC1.By contrast,the expression level of the gene whose function was similar with that of NBC1 was opposite to the expression pattern of NBC1.Conclusions: NBC1 might not only play important roles in pancreatic embryonic development but has some connection with the pancreatic function.