484 BLADDER OVERDISTENSION STIMULATES UROTHELIAL PROLIFERATION WITHOUT APOPTOSIS

Abstract

You have accessJournal of UrologyPediatrics: Neuropathic Bladder/Reconstruction1 Apr 2013484 BLADDER OVERDISTENSION STIMULATES UROTHELIAL PROLIFERATION WITHOUT APOPTOSIS Christina B Ching, Heidi A Stephany, Mariana M Cajaiba, Stacy T Tanaka, John C Thomas, John C Pope, Mark C Adams, John W Brock, and Douglass B Clayton Christina B ChingChristina B Ching Nashville, TN More articles by this author , Heidi A StephanyHeidi A Stephany Nashville, TN More articles by this author , Mariana M CajaibaMariana M Cajaiba Nashville, TN More articles by this author , Stacy T TanakaStacy T Tanaka Nashville, TN More articles by this author , John C ThomasJohn C Thomas Nashville, TN More articles by this author , John C PopeJohn C Pope Nashville, TN More articles by this author , Mark C AdamsMark C Adams Nashville, TN More articles by this author , John W BrockJohn W Brock Nashville, TN More articles by this author , and Douglass B ClaytonDouglass B Clayton Nashville, TN More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.1876AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We have previously shown that bladder overdistension causes hypoxic and ischemic bladder injury. Interested in restorative responses of the bladder, we hypothesized that bladder overdistension would stimulate cell regeneration. METHODS Female C57/Bl6 mice were ovariectomized at 6 weeks. Two experimental mice groups underwent bladder overdistension via catheterization and 0.9% saline infusion at 60cmH20 for 90 minutes under isoflurane general anesthesia. One group (acute distension group) was sacrificed immediately after a single distension (time=0), and at 3 hours (t=3), 6 hours (t=6), and 24 hours (t=24) after recovery. Another group (chronic distension group) underwent a single, daily distension for 5 consecutive days and were then sacrificed. Age-matched ovariectomized controls underwent general anesthesia only for these time points. Bladder tissue was harvested and stained for H&E. Immunohistochemistry was performed for caspase-3 (apoptotic indicator) and Ki-67 (proliferative indicator). In a separate chronic group, Bromodeoxyuridine (BRDU) (proliferative indicator) was injected intraperitoneally 2 hours before sacrifice. Urothelial proliferation was quantified by counting percentage positively staining cells at 400x power. RESULTS Specific histologic differences were observed in experimental groups versus controls. H&E in the acute group demonstrated immediate suburothelial hemorrhage (t=0) and increasing inflammation with time recovery (t=24). Transmural inflammation was observed in the chronic group. Ki-67 staining showed significant urothelial proliferation. At t=24, up to 92% of total urothelial cells were proliferating; in the chronic group, up to 60% were proliferating. In controls, t=0, and t=3, proliferation was seen in only up to 2%. FIGURE 1. Urothelial BRDU staining in the additional chronic group was increased as compared to controls (up to 15% vs. 1%). Caspase-3 staining showed no evidence of urothelial apoptosis in any group. CONCLUSIONS Bladder overdistension results in urothelial proliferation that begins 24 hours after injury. Evidence of apoptosis was not present. Characterizing the balance between urothelial cell death and proliferation can ultimately help understand the deleterious effects of bladder overdistension. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e199 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Christina B Ching Nashville, TN More articles by this author Heidi A Stephany Nashville, TN More articles by this author Mariana M Cajaiba Nashville, TN More articles by this author Stacy T Tanaka Nashville, TN More articles by this author John C Thomas Nashville, TN More articles by this author John C Pope Nashville, TN More articles by this author Mark C Adams Nashville, TN More articles by this author John W Brock Nashville, TN More articles by this author Douglass B Clayton Nashville, TN More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...