Regulation and Function of Uroplankin Genes

尿板蛋白基因的调控和功能

• 批准号: 7468458
• 负责人: Tung-Tien Sun
• 金额: $ 28.14万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7468458
• 关键词: Ablation; Address; Affect; Apical; Area; Bacteria; Binding Proteins; Bladder; Bladder Diseases; Caliber; Cell Surface Proteins; Cells; Cessation of life; Cytoplasmic Protein; Defect; Disease; Employee Strikes; Etiology; Genes; Glycocalyx; Glycoproteins; Grant; Hydronephrosis; Hyperactive behavior; Interstitial Cystitis; Knock-out; Lead; Light; Lip structure; Malignant neoplasm of urinary bladder; Mediating; Membrane; Membrane Proteins; Molecular; Mus; Neonatal; Pathogenesis; Permeability; Play; Proteins; Regulation; Role; Signal Transduction; Structure; Surface; Testing; UPK2 gene; Urinary tract infection; Urination; Urologic Diseases; Urothelium; Vesico-Ureteral Reflux; design; human PHEMX protein; member; particle; receptor; two-dimensional

The apical surface of mammalian urothelium is almost completely covered by rigid-looking urothelial plaques consisting of 16 nm uroplakin particles that are hexagonally packed into two-dimensional crystals. Highly purified urothelial plaques are comprised of four major uroplakins (UP), i.e., uroplakin Ia (27 kDa), Ib (28 kDa), II (15 kDa) and III (47 kDa). The two tetraspanin members UPIa and UPIb interact preferentially with the two single transmembrane-domained uroplakins II and III, respectively, forming two uroplakin pairs consisting of UPIa/II and UPIb/III. During the last grant period, we genetically ablated mouse genes encoding for uroplakins II and III. Mice deficient in these two major urothelial differentiation products have a grossly abnormal urothelium lacking typical umbrella cells; have abnormally small urothelial plaques; and suffer from vesicoureteral reflux, hydronephrosis and, in some cases, neonatal death. These results indicate that uroplakins are integral subunits of the urothelial plaques which contribute to the permeability barrier function, and that urothelial defects may play a role in certain urinary tract diseases. Little is known, however, about how uroplakin defects may affect urothelial and bladder function as a whole, how uroplakins interact with cytoplasmic and other membrane-associated proteins, and how surface-accessible are the uroplakin receptors to the uropathogenic bacteria. The proposed studies in this Project will attempt to answer some of these questions, by studying how the ablation of uroptakin genes affects the permeability barrier and micturition functions of the bladder (Aim 1); how uroplakins interact with some cytoplasmic proteins that may play a role in mediating uroplaldn:cytosketetal interaction and signal transduction (Aim 2); and how accessible uroplakin molecules are on the apical surface of urothelial umbrella cells, and whether there are other uroplakin-associated cell surface proteins that may be related to the urotheliat 'glycocalyx' coating that has been hypothesized to play a key role in several bladder diseases (Aim 3). Results from this Project will shed light on the structure, function and regulation of urothelial plaques, and will have major implications on the molecular etiology and pathogenesis of several important bladder diseases including interstitial cystitis, urinary tract infection and bladder cancer formation.

哺乳动物尿路上皮的顶端表面几乎完全被看起来坚硬的尿路上皮斑块所覆盖，该斑块由16 nm的尿路蛋白颗粒组成，这些颗粒被六角形填充成二维晶体。高纯度的尿路上皮斑块主要由4种主要的尿路蛋白组成，即尿路蛋白Ia(27 KDa)、尿路蛋白Ib(28 KDa)、尿路上皮蛋白II(15 KDa)和尿路上皮蛋白III(47 KDa)。两个Tetraspanin成员UPIA和UPIb分别优先与两个单一跨膜结构域的Uroplakin II和III相互作用，形成两个Uroplakin对 UPIA/II和UPIb/III。在上一个授权期内，我们从基因上切割了编码UPIA/II和UPIb/III的小鼠的尿路上皮细胞。缺乏这两种主要尿路上皮分化产物的小鼠有严重的异常尿路上皮缺乏典型的伞状细胞；有异常小的尿路上皮斑块；并遭受膀胱输尿管反流、肾积水，在某些情况下，新生儿死亡。这些结果表明，尿路上皮细胞因子是尿路上皮细胞斑块的组成部分，具有通透性屏障功能，尿路上皮细胞缺陷可能在某些尿路疾病中起一定作用。然而，关于尿路蛋白缺陷如何影响尿路上皮和膀胱整体功能，以及尿路蛋白如何与尿路上皮和膀胱功能相互作用，人们知之甚少。 细胞质和其他膜相关蛋白，以及尿路致病细菌如何在表面接触到尿路蛋白受体。本项目中拟议的研究将试图通过以下研究来回答其中一些问题：去除尿路蛋白基因如何影响膀胱的通透性屏障和排尿功能(目标1)；尿路蛋白如何与一些可能在介导尿路蛋白中发挥作用的细胞质蛋白相互作用：细胞酮相互作用和信号转导(目标2)；以及尿路上皮伞细胞的顶面如何可获得尿路蛋白分子，以及是否存在其他与尿路蛋白相关的尿路蛋白分子。 细胞表面蛋白，可能与尿路结石‘糖萼’涂层有关 假定在几种膀胱疾病中起关键作用(目标3)。本项目的研究结果将揭示尿路上皮斑块的结构、功能和调控机制，并将对间质性膀胱炎、尿路感染和膀胱癌形成等几种重要膀胱疾病的分子病因学和发病机制具有重要意义。