Endoglin negatively regulates transforming growth factor beta1-induced profibrotic responses in intestinal fibroblasts.
Affiliation
Department of Surgery, St Vincent's University Hospital, Dublin, Ireland.Issue Date
2012-02-01T10:35:25ZMeSH
AdultAged
Aged, 80 and over
Antigens, CD/metabolism/*physiology
Blotting, Western
Cells, Cultured
Crohn Disease/metabolism
Fibroblasts/*metabolism
Humans
Microscopy, Confocal
Middle Aged
Receptors, Cell Surface/metabolism/*physiology
Transforming Growth Factor beta1/*metabolism
Metadata
Show full item recordCitation
Br J Surg. 2010 Jun;97(6):892-901.Journal
The British journal of surgeryDOI
10.1002/bjs.6996PubMed ID
20473999Abstract
BACKGROUND: Fibroblasts isolated from strictures in Crohn's disease (CD) exhibit reduced responsiveness to stimulation with transforming growth factor (TGF) beta1. TGF-beta1, acting through the smad pathway, is critical to fibroblast-mediated intestinal fibrosis. The membrane glycoprotein, endoglin, is a negative regulator of TGF-beta1. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies of patients undergoing intestinal resection for CD strictures or from control patients. Endoglin expression was assessed using confocal microscopy, flow cytometry and western blot. The effect of small interfering (si) RNA-mediated knockdown and plasmid-mediated overexpression of endoglin on fibroblast responsiveness to TGF-beta1 was assessed by examining smad phosphorylation, smad binding element (SBE) promoter activity, connective tissue growth factor (CTGF) expression and ability to contract collagen. RESULTS: Crohn's stricture fibroblasts expressed increased constitutive cell-surface and whole-cell endoglin relative to control cells. Endoglin co-localized with filamentous actin. Fibroblasts treated with siRNA directed against endoglin exhibited enhanced TGF-beta1-mediated smad-3 phosphorylation, and collagen contraction. Cells transfected with an endoglin plasmid did not respond to TGF-beta1 by exhibiting SBE promoter activity or producing CTGF. CONCLUSION: Fibroblasts from strictures in CD express increased constitutive endoglin. Endoglin is a negative regulator of TGF-beta1 signalling in the intestinal fibroblast, modulating smad-3 phosphorylation, SBE promoter activity, CTGF production and collagen contraction.Language
engISSN
1365-2168 (Electronic)0007-1323 (Linking)
ae974a485f413a2113503eed53cd6c53
10.1002/bjs.6996