Institute of Cell Biology, Faculty of Medicine, University of Ljubljana.
Eur J Histochem. 2021 Mar 24;65(2):3242. doi: 10.4081/ejh.2021.3242.
The urothelium, an epithelium of the urinary bladder, primarily functions as blood-urine permeability barrier. The urothelium has a very slow turn-over under normal conditions but is capable of extremely fast response to injury. During regeneration urothelium either restores normal function or undergoes altered differentiation pathways, the latter being the cause of several bladder diseases. In this review, we describe the structure of the apical plasma membrane that enables barrier function, the role of urothelium specific proteins uroplakins and the machinery for polarized membrane transports in terminally differentiated superficial umbrella cells. We address key markers, such as keratins, cancer stem cell markers, retinoic acid signalling pathway proteins and transient receptor potential channels and purinergic receptors that drive normal and altered differentiation in bladder cancer and bladder pain syndrome. Finally, we discuss uncertainties regarding research, diagnosis and treatment of bladder pain syndrome. Throughout the review, we emphasise the contribution of immunohistochemistry in advancing our understanding of processes in normal and diseased bladder as well as the most promising possibilities for improved bladder cancer and bladder pain syndrome management.
尿路上皮是膀胱的上皮组织，主要起到血-尿屏障的作用。在正常情况下，尿路上皮的更新速度非常缓慢，但它能够对损伤做出极其迅速的反应。在再生过程中，尿路上皮要么恢复正常功能，要么经历不同的分化途径，后者是几种膀胱疾病的病因。在这篇综述中，我们描述了能够实现屏障功能的顶端质膜的结构、尿路上皮特异性蛋白尿路上皮磷蛋白和极性膜转运机制在终末分化的表面伞细胞中的作用。我们讨论了一些关键标志物，如角蛋白、癌症干细胞标志物、视黄酸信号通路蛋白、瞬时受体电位通道和嘌呤能受体，这些标志物在膀胱癌和膀胱疼痛综合征的正常和异常分化中起驱动作用。最后，我们讨论了有关膀胱疼痛综合征的研究、诊断和治疗的不确定性。在整篇综述中，我们强调了免疫组织化学在深入了解正常和患病膀胱的过程中的贡献，以及改善膀胱癌和膀胱疼痛综合征管理的最有前途的可能性。
