490 GATA-6 AND NF-κB SYNERGISTICALLY UPREGULATES CPI-17 GENE EXPRESSION IN OBSTRUCTION-INDUCED MURINE BLADDER SMOOTH MUSCLE HYPERTROPHY

Abstract

You have accessJournal of UrologyBladder and Urethra: Anatomy, Physiology and Pharmacology II1 Apr 2012490 GATA-6 AND NF-κB SYNERGISTICALLY UPREGULATES CPI-17 GENE EXPRESSION IN OBSTRUCTION-INDUCED MURINE BLADDER SMOOTH MUSCLE HYPERTROPHY Ettickan Boopathi, Joseph Hypolite, Stephen Zderic, Alan Wein, and Samuel Chacko Ettickan BoopathiEttickan Boopathi Glenolden, PA More articles by this author , Joseph HypoliteJoseph Hypolite Glenolden, PA More articles by this author , Stephen ZdericStephen Zderic Philadelphia, PA More articles by this author , Alan WeinAlan Wein Philadelphia, PA More articles by this author , and Samuel ChackoSamuel Chacko Glenolden, PA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.560AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Partial Bladder Outlet Obstruction (PBOO) has long been considered the key factor in the mechanism through which benign prostatic hyperplasia causes urinary bladder symptoms and it is associated with detrusor smooth muscle (DSM) remodeling, including hypertrophy, altered bladder contractility that eventually leads to bladder dysfunction. Protein kinase C (PKC) signaling via the proteins involved in Ca2+-sensitization pathway plays an important role in smooth muscle contraction to maintain MLC20 in the phosphorylated state. CPI-17, a member of calcium sanitization pathway has been shown to be upregulated in PBOO-induced DSM hypertrophy in the rabbit bladder smooth muscle. In this study, we provide the molecular mechanisms that mediates the upregulation of CPI-17 gene expression in PBOO-induced hypertrophic DSM. METHODS Bladder smooth muscle from control mice and those subjected to 2 weeks of partial bladder outlet obstruction were used for PCR, western blotting, immunohistochemistry, promoter pull down, and ChIP assay. Bladder smooth muscle strips from control and NF-κB knockout mice, which show a downregulation of CPI-17, were used for force measurements. Mouse bladder primary smooth muscle cells were used for transfection with GATA-6, NF-κB cDNA and CPI-17 promoter construct. RESULTS We identified an enhancer element in the promoter of CPI-17 gene that recruits the transcription factor GATA-6 and NF-κB. Furthermore, we demonstrate that CPI-17 expression level directly correlates with the NF-κB and GATA-6 abundance level in murine bladder smooth muscle following PBOO. Overexpression of GATA-6 and NF-κB in murine bladder primary smooth muscle cells synergistically upregulates the CPI-17 gene expression. Importantly, silencing of GATA-6 and NF-κB gene expression down-regulates CPI-17 expression. DSM strips from NF-κB knockout mouse generates lower force in response to PKC agonists PDBu compared to control. CONCLUSIONS These results confirm that both GATA-6 and NF-κB are required for CPI-17 gene expression and their synergetic action on CPI-17 promoter results in increased CPI-17 gene transcription. In addition, NF-κB is essential for PKC-mediated signaling in murine DSM contraction. The aberrant expression of GATA-6 and NF-κB and their synergetic transcriptional activation contributes to overexpression of CPI-17 in obstruction-induced DSM hypertrophy. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e200-e201 Peer Review Report Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ettickan Boopathi Glenolden, PA More articles by this author Joseph Hypolite Glenolden, PA More articles by this author Stephen Zderic Philadelphia, PA More articles by this author Alan Wein Philadelphia, PA More articles by this author Samuel Chacko Glenolden, PA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...