title: MicroRNA 29 targets nuclear factor-κB-repressing factor and Claudin 1 to increase intestinal permeability.
abstract: OBJECTIVE
  Some patients with irritable bowel syndrome with diarrhea (IBS-D) have intestinal hyperpermeability, which contributes to their diarrhea and abdominal pain. MicroRNA 29 (MIR29) regulates intestinal permeability in patients with IBS-D. We investigated and searched for targets of MIR29 and investigated the effects of disrupting Mir29 in mice.
  
  
  METHODS
  We investigated expression MIR29A and B in intestinal biopsies collected during endoscopy from patients with IBS (n = 183) and without IBS (controls) (n = 36). Levels were correlated with disease phenotype. We also generated and studied Mir29(-/-) mice, in which expression of Mir29a and b, but not c, is lost. Colitis was induced by administration of 2,4,6-trinitrobenzenesulfonic acid; intestinal tissues were collected and permeability was assessed. Microarray analysis was performed using tissues from Mir29(-/-) mice. Changes in levels of target genes were measured in human colonic epithelial cells and small intestinal epithelial cells after knockdown of MIR29 with anti-MIRs.
  
  
  RESULTS
  Intestinal tissues from patients with IBS-D (but not IBS with constipation or controls) had increased levels of MIR29A and B, but reduced levels of Claudin-1 (CLDN1) and nuclear factor-κB-repressing factor (NKRF). Induction of colitis and water avoidance stress increased levels of Mir29a and Mir29b and intestinal permeability in wild-type mice; these increased intestinal permeability in colons of far fewer Mir29(-/-) mice. In microarray and knockdown experiments, MIR29A and B were found to reduce levels of NKRF and CLDN1 messenger RNA, and alter levels of other messenger RNAs that regulate intestinal permeability.
  
  
  CONCLUSIONS
  Based on experiments in knockout mice and analyses of intestinal tissue samples from patients with IBS-D, MIR29 targets and reduces expression of CLDN1 and NKRF to increase intestinal permeability. Strategies to block MIR29 might be developed to restore intestinal permeability in patients with IBS-D.
authors.affiliation: Department of Medicine, University of Texas Medical Branch, Galveston, Texas; Department of Veteran Affairs, Cincinnati VA Medical Center, Cincinnati, Ohio.
authors.forename: QiQi
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio.
authors.forename: Stefan
authors.initials: S
authors.lastname: Costinean
authors.affiliation: Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio.
authors.forename: Carlo M
authors.initials: CM
authors.lastname: Croce
authors.affiliation: Department of Medicine, University of Texas Medical Branch, Galveston, Texas.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Brasier
authors.affiliation: Department of Medicine, University of Texas Medical Branch, Galveston, Texas.
authors.forename: Shehzad
authors.initials: S
authors.lastname: Merwat
authors.affiliation: Department of Medicine, University of Texas Medical Branch, Galveston, Texas.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Larson
authors.affiliation: Department of Medicine, University of Texas Medical Branch, Galveston, Texas.
authors.forename: Sarpreet
authors.initials: S
authors.lastname: Basra
authors.affiliation: Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana. Electronic address: gverne@tulane.edu.
authors.forename: G Nicholas
authors.initials: GN
authors.lastname: Verne
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D002460:Cell Line; D062445:Claudin-1 / Q000235:genetics / Q000378:metabolism*; D003092:Colitis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D003106:Colon / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D015536:Down-Regulation; D055785:Gene Knockdown Techniques; D020022:Genetic Predisposition to Disease; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010539:Permeability; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014302:Trinitrobenzenesulfonic Acid
chemical_list: C568108:CLDN1 protein, human; D062445:Claudin-1; C568113:Cldn1 protein, mouse; C547014:MIRN29 microRNA, mouse; C532045:MIRN29a microRNA, human; D035683:MicroRNAs; C111027:NKRF protein, human; C522199:NKRF protein, mouse; D012333:RNA, Messenger; D012097:Repressor Proteins; D014302:Trinitrobenzenesulfonic Acid
keywords: Gene Regulation; Intestinal Barrier Function; Mouse Model; mRNA Processing