Localization of P2X receptor subtypes 2, 3 and 7 in human urinary bladder

Abstract

BackgroundVoiding dysfunctions are a common problem that has a severe negative impact on the quality of life. Today there is a need for new drug targets for these conditions. The role of ATP receptors in bladder physiology has been studied for some time, primarily in animal models. The aim of this work is to investigate the localization of the ATP receptors P2X2, P2X3 and P2X7 and their colocalization with vimentin and actin in the human urinary bladder.MethodsImmunohistochemical analysis was conducted on full-thickness bladder tissues from fundus and trigonum collected from 15 patients undergoing open radical cystectomy due to chronic cystitis, bladder cancer or locally advanced prostate cancer. Colocalization analyses were performed between the three different P2X subtypes and the structural proteins vimentin and actin. Specimens were examined using epifluorescence microscopy and correlation coefficients were calculated for each costaining as well as the mean distance from the laminin positive basal side of the urothelium to the vimentin positive cells located in the suburothelium.ResultsP2X2 was expressed in vimentin positive cells located in the suburothelium. Less distinct labelling of P2X2 was also observed in actin positive smooth muscle cells and in the urothelium. P2X3 was expressed in vimentin positive cells surrounding the smooth muscle, and in vimentin positive cells located in the suburothelium. Weaker P2X3 labelling was seen in the urothelium. P2X7 was expressed in the smooth muscle cells and the urothelium. In the suburothelium, cells double positive for P2X2 and vimentin where located closer to the urothelium while cells double positive for P2X3 and vimentin where located further from the urothelium.ConclusionThe results from this study demonstrate that there is a significant difference in the expression of the purinergic P2X2, P2X3 and P2X7 receptors in the different histological layers of the human urinary bladder.

Is electrolyte transfer across the urothelium important?: ICI‐RS 2015

“…Vial and Evans demonstrated P2X2, P2X4, and P2X7 on mouse bladder urothelium, moreover all P2Xs were found to be expressed in feline bladder urothelium . P2X1, P2X2, P2X3, P2X6, and P2X7 are expressed on human urothelial cells . The potential involvement of P2X receptor/channels in ion transport in the context of urine modification is unknown; however, it is known that P2X receptors on umbrella cells may contribute to apical membrane insertion triggered by Ca 2+ ‐influx .…”

Molecular Structure and Regulation of P2X Receptors With a Special Emphasis on the Role of P2X2in the Auditory System

“…P2X 2 receptors are widely expressed in both the central and peripheral nervous system, as well as in the pituitary gland (Lynch et al, ), oocytes, and human urinary bladder cells, (Svennersten et al, ). P2X 2 receptors exhibit moderate permeability to calcium ions, with permeability lower than that of P2X 1 and P2X 4 , but higher than that of P2X 3 .…”

“…To further distinguish the P2 receptors, the subclasses have been divided into families of metabotropic (P2Y, P2U, and P2T) and ionotropic receptors (P2X and P2Z). The family of P2X receptors consists of cation‐permeable ligand‐gated ion channels that open upon ATP binding and are found in multiple species ranging from the eukaryote green algae Osterococcus tauri to humans (Fountain et al, ; Tran et al, ; Sánchez‐Nogueiro et al, ; Okura et al, ; Svennersten et al, ; Xiao et al, ). There are seven distinct types of P2X subunits, P2X 1 to P2X 7 (North, ; Aschrafi et al, ; Saul et al, ).…”

Micromechanical stimulation chips for studying mechanotransduction in micturition

“…Recently, the expression of purinergic receptors has been mapped in different regions and cells, such as the ICC-like cells, in the bladder. [2] Activation of these receptors leads, via a series of events, to an increase in intracellular [Ca 2+ ] which in turn regulates many cellular processes. The increase in [Ca 2+ ] can be measured in real time using Ca 2+ binding dyes.…”