title: Role of MutS homolog 2 (MSH2) in intestinal myofibroblast proliferation during Crohn's disease stricture formation.
abstract: Tissue remodeling and mesenchymal cell accumulation accompanies chronic inflammatory disorders involving joints, lung, vasculature, and bowel. Chronic inflammation may alter DNA-mismatch repair (MMR) systems in mesenchymal cells, but is not defined in Crohn's disease (CD) and its associated intestinal remodeling and stricture formation. We determined whether DNA-MMR alteration plays a role in the pathogenesis of CD tissue remodeling. Control and CD bowel tissues were used to generate primary cultures of muscularis mucosa myofibroblasts, which were assessed directly or following stimulation with TNF-alpha/LPS or H2O2. MutS homolog (MSH)2, MSH3, and MSH6 expression in tissues and myofibroblasts was determined. Immunohistochemical staining revealed an increased expression of MSH2 in CD muscularis mucosa and submucosal tissues compared with controls or uninvolved CD tissue, and MSH2 expression was increased in CD myofibroblasts compared with control cells. TNF-alpha/LPS and H2O2 further enhanced MSH2 expression in both control and CD cells, which were decreased by simvastatin. There were no significant changes in MSH3 and MSH6 expression. Proliferating cell nuclear antigen and Ki67 staining of CD tissue revealed increased proliferation in the muscularis mucosa and submucosa of chronically inflamed tissues, and enhanced proliferation was seen in CD myofibroblasts compared with controls. Simvastatin reversed the effects of inflammatory stress on the DNA-MMR and inhibited proliferation of control and CD myofibroblasts. Gene silencing with MSH2 siRNA selectively decreased CD myofibroblast proliferation. These data demonstrate a potential role for MSH2 in the pathogenesis of nonneoplastic mesenchymal cell accumulation and intestinal remodeling in CD chronic inflammation.
authors.affiliation: Department of Medicine, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Floer
authors.forename: David G
authors.initials: DG
authors.lastname: Binion
authors.forename: Victoria M
authors.initials: VM
authors.lastname: Nelson
authors.forename: Sharon
authors.initials: S
authors.lastname: Manley
authors.forename: Michael
authors.initials: M
authors.lastname: Wellner
authors.forename: Saba
authors.initials: S
authors.lastname: Sadeghi
authors.forename: Behnaz
authors.initials: B
authors.lastname: Behmaram
authors.forename: Chloe
authors.initials: C
authors.lastname: Sewell
authors.forename: Mary F
authors.initials: MF
authors.lastname: Otterson
authors.forename: Torsten
authors.initials: T
authors.lastname: Kucharzik
authors.forename: Parvaneh
authors.initials: P
authors.lastname: Rafiee
mesh_terms: D000328:Adult; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003424:Crohn Disease / Q000150:complications / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D005455:Fluorescent Antibody Technique; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology; D007150:Immunohistochemistry; D007415:Intestinal Obstruction / Q000201:enzymology / Q000209:etiology* / Q000235:genetics / Q000473:pathology; D007422:Intestines / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D051718:MutS Homolog 2 Protein / Q000235:genetics / Q000378:metabolism*; D000074081:MutS Homolog 3 Protein; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D019821:Simvastatin / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008070:Lipopolysaccharides; C078444:MSH3 protein, human; D000074081:MutS Homolog 3 Protein; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; D019821:Simvastatin; D006861:Hydrogen Peroxide; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein; D013936:Thymidine