441 EMBRYONIC SMOOTH MUSCLE INDUCES BLADDER SMOOTH MUSCLE DIFFERENTIATION

Abstract

You have accessJournal of UrologyBladder and Urethra: Anatomy, Physiology and Pharmacology II1 Apr 2010441 EMBRYONIC SMOOTH MUSCLE INDUCES BLADDER SMOOTH MUSCLE DIFFERENTIATION Gregory Tasian, Mei Cao, Gerald Cunha, and Laurence Baskin Gregory TasianGregory Tasian More articles by this author , Mei CaoMei Cao More articles by this author , Gerald CunhaGerald Cunha More articles by this author , and Laurence BaskinLaurence Baskin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.512AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Urothelium-derived signals are necessary to induce smooth muscle differentiation from mesenchyme during murine bladder development. We tested the hypothesis that fetal bladder smooth muscle without urothelium can induce smooth muscle differentiation from bladder mesenchyme. METHODS Fetal intact bladders (IB) were harvested from timed pregnant FVB and transgenic GFP mice at the time points shown below. Bladder mesenchyme (BLM) was isolated by incubating IB in 0.02M EDTA and then removing the urothelium by microdissection. Embryonic day (E) 12 BLM from GFP mice was recombined with E12 BLM, E12 IB, and E16 BLM from FVB mice and incubated overnight on agar at 37°C. The recombined tissues were grafted beneath the kidney capsule of male nude mice, maintained for two weeks, and then were harvested and processed. H&E staining was performed and immunohistochemistry and immunofluoresence staining was used to detect smooth muscle α-actin, uroplakin and GFP. RESULTS At the time of harvest, E12 BLM does not express α-actin; E16 BLM does express α-actin. E12 BLM (GFP) recombined with E12 BLM (FVB) did not survive. E12 BLM (GFP) expressed smooth muscle α-actin when recombined with E12 IB (FVB). The α-actin positive cells derived from E12 BLM (GFP) diffusely migrated through the smooth muscle of the FVB bladder wall. When recombined with E16 BLM (FVB), E12 BLM (GFP) also demonstrated smooth muscle differentiation, as shown by the expression of smooth muscle α-actin; however, these cells did not migrate (see Figure). CONCLUSIONS Urothelium is necessary for initial induction of smooth muscle differentiation from bladder mesenchyme. After smooth muscle has formed, BLM alone can induce further smooth muscle differentiation. This may be due to an intrinsic property of smooth muscle, presence of a diffusible factor within the mesenchyme that induces smooth muscle differentiation, or initiation of signaling pathways by the urothelium prior to its removal that result in mesenchymal smooth muscle differentiation. San Francisco, CA© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e174 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Gregory Tasian More articles by this author Mei Cao More articles by this author Gerald Cunha More articles by this author Laurence Baskin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...