Human Bladder Urothelial Cell Structure and Function in Bladder Hypersensation

描述（由申请人提供）：膀胱尿路上皮细胞（BUG）与人类疾病的相关性传统上仅被理解为尿路上皮细胞癌。然而，有令人兴奋的新文献强调了在非肿瘤状态下改变的BUG结构和功能的作用。间质性膀胱炎（IC）和膀胱过度活动症（OAB）这两种高度流行但知之甚少的疾病都可能与膀胱尿路炎的致病性变化有关。这两种疾病的特征是超感觉症状，如尿急，尿频和膀胱疼痛。 我们建议研究膀胱尿路上皮的结构和功能，因为它涉及到IC和OAB的正常和超感觉条件。最近的扫描电子显微镜的膀胱尿路上皮的内腔侧显示IC和控制顶伞细胞（AUC）之间的明显变化。这些变化可能是由于尿斑蛋白表达异常。尿斑蛋白是仅由尿路上皮中的AUC表达的独特蛋白质，并且在AUC膜结构和功能中起作用。在培养物中生长的人IC布克C也具有异常，包括增强的嘌呤能信号传导、改变的某些生长因子（HB-EGF、EGF和APF）的表达和降低的钾电导（由离子通道Kir2.1和BK介导），导致去极化。在膀胱尿路上皮上发现毒蕈碱M2受体为使用抗毒蕈碱药物治疗OAB提供了另一种作用机制。 本研究将检验以下4个假设：1。来自膀胱感觉过敏症患者的AUC具有与尿斑蛋白相关的结构异常。2.膀胱感觉过敏症患者的膀胱尿道炎改变了紧密连接蛋白（ZO-1，occludin）、Kir2.1、BK、M2、HB-EGF、EGF和APF的蛋白表达。3. IC布克中离子通道Kir2.1的电导降低。这种情况可以通过EGF治疗来缓解。APF治疗可使正常布克细胞Kir2.1电导降低。4.在人布克中，BK通道的电导由M2受体调节。OAB和IC布克C的外向钾电流均降低，hSIo cDNA转染可逆转该现象。通过实现这些目标，我们希望了解膀胱感觉过敏症的发病机制，最终可以找到有针对性的治疗方案。

DESCRIPTION (provided by applicant): The relevance of bladder urothelial cells (BUG) to human disease has traditionally been understood only in terms of urothelial cell carcinoma. However, there is exciting new literature highlighting the role of altered BUG structure and function in non-neoplastic states. Two highly prevalent yet poorly understood conditions, interstitial cystitis (IC) and overactive bladder (OAB) may both be associated with pathogenic changes in the bladder urothelium. Both of these conditions are characterized by hypersensory symptoms such as urinary urgency, frequency, and bladder pain. We propose to study the structure and function of the bladder urothelium as it relates to both normal and hypersensory conditions of IC and OAB. Recent scanning electron microscopy of the lumenal side of the bladder urothelium show distinct changes between IC and control apical umbrella cells (AUC). These changes could be due to abnormalities in uroplakins expression. Uroplakins are unique proteins expressed only by the AUC in the urothelium and play a role in AUC membrane structure and function. Human IC BUC grown in culture also had abnormalities including augmented purinergic signaling, altered expression of certain growth factors (HB-EGF, EGF and APF), and decreased potassium conductance (mediated by ion channels Kir2.1 and BK) leading to depolarization. The discovery of muscarinic M2 receptors on the bladder urothelium provides another mechanism of action in the use of antimuscarinics in treatment of OAB. This grant will test the following 4 hypotheses: 1. AUC from patients with bladder hypersensory conditions have structural abnormalities related to uroplakins. 2. The bladder urothelium from patients with bladder hypersensory conditions have altered protein expressions of tight junction proteins (ZO-1, occludin), Kir2.1, BK, M2, HB-EGF, EGF and APF. 3. The conductance of ion channel Kir2.1 is decreased in IC BUC. This can be reversed with HB-EGF treatment. Normal BUC can be made to have decreased Kir2.1 conductance with APF treatment. 4. The conductance of the BK channel is regulated by M2 receptors in human BUC. There is a decreased outward potassium current in OAB and IC BUC which can be reversed by hSIo cDNA transfection. By accomplishing these aims, we hope to develop an understanding of the pathogenesis of hypersensory bladder conditions which ultimately can lead to targeted treatment options.