钠-氢交换蛋白mRNA在人胎儿两个发育阶段中的组织特异性表达  

Tissue-specific expression of Na^+-H^+ exchanger isoforms at two developmental stages of human fetus

作　　者：林万敏[1] 陈献华[1] 徐容[2] 刘璇[1] 徐平[1] 

机构地区：[1]复旦大学生命科学学院脑研究中心 [2]华东师范大学生命科学学院,上海200062

出　　处：《生理学报》2003年第1期79-82,共4页Acta Physiologica Sinica

摘　　要：钠 氢交换蛋白 (Na+ H+ exchangers ,NHE)至少包含 6个不同的亚型 ,生长因子可激活其表达。目前 ,对在发育过程中NHE的表达了解甚少。本文利用RT PCR观察了 4种NHE亚型的mRNA在人胎儿的两个不同发育阶段 (11周、16周 )在不同组织中的表达 ,以研究它们的发育调控。结果显示 ,NHE1mRNA在两种胎龄的多种组织中均有表达。和 16周胚胎相比 ,11周的胚胎的NHE1mRNA的表达较弱 ,并且表现出明显的组织差异。据此推测 ,NHE1的管家 (house keeping)功能可能至少在 11周就开始形成 ,而最迟在 16周已基本建立 ;NHE2和NHE3mRNA在 11周和16周的胚胎组织中的特异性表达呈现相反的变化趋势及组织分布上的重叠 ,后者与NHE2和NHE3在成人组织中的分布及功能的重叠的特点相吻合 ;NHE5mRNA的表达在 11周的胚胎组织中比较普遍 ,而在 16周的胚胎组织中则局限在小脑组织中。本研究表明 ,在人胚胎发育的 11～ 16周期间 ,NHE的组织特异性表达表现出时间依赖性的调控 ,而在不迟于胚胎发育的第 16周 ,具有“管家功能”Na + H + exchangers (NHE) are major membrane proteins that have been identified as signal transduction mediators in the regulation of cell differentiation and important membrane ion transporters in the regulation of the intercellular pH and the cell volume NHE are composed of at least six isoforms and activated in growth factor regulated cell differentiation. However, little is known about the differential regulation of NHE expression in the development. In the present study, we studied developmental regulation of the expression of NHE isoforms in human fetal tissues by comparing the expression of various isoforms between two developmental stages, i e , week 11 (11 W) and week 16 (16 W). The results demonstrated that NHE1 transcripts were expressed ubiquitously. In comparison to the expression at 16 W, the level of NHE1 transcripts was low and varied significantly in a tissue specific pattern at 11 W, suggesting that the 'house keeping' function of MHE1 occurs at 11 W or earlier and becomes well established at least as early as at 16 W. The tissue specifically restricted expression of NHE2 and NHE3 was regulated at 11 W and 16 W in an opposite tendency, supporting the overlapping relationship between NHE2 and NHE3 in the tissue distribution as reported in adults. NHE5 expression was relatively ubiquitous at 11 W and became restricted in the cerebellum at 16 W, suggesting that the restrictive expression of NHE5 in the brain occurs later than that of other isoforms. The present study demonstrates a space time dependent regulation of the tissue specific expression pattern of NHE isoforms during human development between 11 W and 16 W. The results also suggest that at 16 W or earlier the expression pattern of developing tissues becomes similar to that of adult tissues. The observed developmental regulation of NHE expression provides a molecular basis for further study of the function and regulation of NHE gene during development.

关 键 词：生理学 基因表达 RT-PCR Na^+-H^+交换蛋白 

分 类 号：R321[医药卫生—人体解剖和组织胚胎学]