利尿钠肽对小鼠耳蜗血管纹边缘细胞的调节作用

Meniere's disease is a common disease which can seriously impact on the patient's quality of life. Due to lack of effective treatment options, this disease has become an important clinical problem that needs to be urgently solved. Meniere's disease is an idiopathic inner ear disease, characterized by its clinical manifestations such as vertigo, deafness, tinnitus, and ear fullness. The underlying pathological feature of Meniere's disease is endolymphatic hydrops. Although the exact etiology of this disease is still unclear, imbalance of the ionic environment within the endolymphatic system and the excessive secretion of the marginal cells are thought to be the main causes. The present results of the research indicate that atrialnatriuretic peptide (ANP) and natriuretic peptide, C-Type(CNP) may play an important role in regulating the endolymph homeostasis. The objective of the current project is to understand the regulatory role of natriuretic peptides(NPs) in the stria marginal cells and the endolymph homeostasis. A special technology will be applied to obtain the freshly isolated mouse stria vascularis and western blot, real-time RT-PCR and patch-clamp technique will be utilized to determine the effect of ANP on mRNA and protein expression levels of three different subunits of ENaC and the effect of CNP on mRNA and protein expression levels of IsK channel subunit and to examine the influence of ANP on ENaC and CNP on IsK channel currents in mouse strial marginal cells. These studies will provide novel insights into the pathogenic mechanisms of Meniere's disease and may lead to new therapies for this disease by specifically modulating the NPs signaling.

梅尼埃病严重影响患者的生活质量，且缺乏彻底而无副作用的治疗手段，已成为耳科临床迫切需要解决的难题。梅尼埃病是以膜迷路积水为基本病理改变，以发作性眩晕、耳聋、耳鸣和耳胀满感为临床特征的特发性内耳疾病。其确切病因不清，主要认为它是由内淋巴离子环境和容量失衡引起的，血管纹边缘细胞分泌过度是其主要病因之一。从现有的研究结果可推测房利尿钠肽(ANP)和C型利尿钠肽(CNP)可能对内淋巴稳态起重要调节作用。本课题将应用特殊的急性分离内耳血管纹的技术、分子生物学技术和膜片钳技术，首次检测ANP对血管纹的ENaC三种亚基mRNA和蛋白质表达量的影响以及CNP对血管纹的IsK通道亚基mRNA和蛋白质表达量的影响；首次研究ANP对边缘细胞的ENaC电流的影响及CNP对边缘细胞的IsK通道电流的影响，以研究NP对血管纹边缘细胞及内淋巴稳态的调节作用。本课题可能为发现调节NP信号通路治疗梅尼埃病的新方法打下基础。

梅尼埃病是以膜迷路积水为基本病理改变，以发作性眩晕、耳聋、耳鸣和耳胀满感为临床特征的特发性内耳疾病。其确切病因不清，主要认为它是由内淋巴离子环境和容量失衡引起的，血管纹边缘细胞分泌过度是其主要病因之一。房利尿钠肽(ANP)和C型利尿钠肽(CNP)存在于耳蜗血管纹，它们可能参与了相关的水电解质平衡。本课题应用特殊的急性分离内耳血管纹的技术、分子生物学技术和膜片钳技术，首次检测ANP对血管纹的ENaC三种亚基mRNA和蛋白质表达量的影响以及CNP对血管纹的IsK通道亚基mRNA和蛋白质表达量的影响；首次研究ANP对边缘细胞的ENaC电流的影响及CNP对边缘细胞的IsK通道电流的影响，以研究NP对血管纹边缘细胞及内淋巴稳态的调节作用。从现有的研究可推测房利尿钠肽(ANP)和C型利尿钠肽(CNP)可能对内淋巴稳态起重要调节作用。本课题还研究了LPS致炎症性膜迷路积水小鼠耳蜗血管纹血迷路屏障通透性的组织病理学改变，以及血迷路屏障中紧密连接相关蛋白ZO-1及Occludin等的表达，发现紧密连接相关蛋白表达下降导致血迷路屏障通透性增强可能是引起膜迷路积水的原因之一。