Transforming growth factor β signalling and matrix metalloproteinases in the mucosa overlying Crohn’s disease strictures

• Published in: Gut Vol. 58; no. 6; pp. 777 - 789
• Main Authors: Di Sabatino, A, Jackson, C L, Pickard, K M, Buckley, M, Rovedatti, L, Leakey, N A B, Picariello, L, Cazzola, P, Monteleone, G, Tonelli, F, Corazza, G R, MacDonald, T T, Pender, S L
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Society of Gastroenterology 01.06.2009; BMJ Publishing Group
• Subjects: Adult; Aged; Apoptosis; Biological and medical sciences; Blotting, Western - methods; Case-Control Studies; Cells, Cultured; Cellular Senescence; Colon - pathology; Crohn Disease - metabolism; Crohn Disease - pathology; Fibroblasts - metabolism; Fibrosis; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Intestinal Mucosa - metabolism; Intestinal Mucosa - pathology; Matrix Metalloproteinase 12 - analysis; Matrix Metalloproteinase 12 - genetics; Matrix Metalloproteinase 12 - metabolism; Matrix Metalloproteinase 3 - analysis; Matrix Metalloproteinase 3 - genetics; Matrix Metalloproteinase 3 - metabolism; Matrix Metalloproteinases - analysis; Matrix Metalloproteinases - biosynthesis; Medical sciences; Middle Aged; Other diseases. Semiology; Reverse Transcriptase Polymerase Chain Reaction - methods; Signal Transduction - physiology; Smad2 Protein - analysis; Smad2 Protein - genetics; Smad2 Protein - metabolism; Smad3 Protein - analysis; Smad3 Protein - genetics; Smad3 Protein - metabolism; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Tissue Inhibitor of Metalloproteinase-1 - analysis; Tissue Inhibitor of Metalloproteinase-1 - metabolism; Transforming Growth Factor beta - analysis; Transforming Growth Factor beta - genetics; Transforming Growth Factor beta - metabolism; Young Adult; Crohn disease; Transforming growth factor β; Gastroenterology; Stenosis; Digestive diseases; Intestinal disease; Mucosa disease; Signalling; Inflammatory disease
• ISSN: 0017-5749; 1468-3288
• DOI: 10.1136/gut.2008.149096

Background and Aims:In addition to its crucial role in dampening tissue-damaging immune responses in the gut, transforming growth factor β (TGFβ) is a potent profibrogenic agent inducing collagen synthesis and regulating the balance between matrix-degrading matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). TGFβ signalling was investigated by analysis of Smad proteins and MMPs/TIMPs in the mucosa overlying strictures in patients with Crohn’s disease (CD).Methods:Specimens were collected from macroscopically normal mucosa overlying strictured and non-strictured gut of patients with fibrostenosing CD. Isolated myofibroblasts were cultured with anti-TGFβ blocking antibody or TGFβ1. TGFβ transcripts were analysed by quantitative reverse transcription-PCR (RT-PCR). Smad proteins and MMPs were determined by immunoblotting. MMP-12 activity was measured by a real-time MMP-12 activity assay. An in vitro wound-healing scratch assay was used to assess myofibroblast migration.Results:TGFβ transcripts, phosphorylated Smad2–Smad3 (pSmad2–3) and TIMP-1 proteins were higher in mucosa overlying strictures than in mucosa overlying non-strictured areas. In contrast, mucosa overlying strictured gut had lower expression of Smad7, MMP-12 and MMP-3. Myofibroblasts from mucosa overlying strictured gut showed higher TGFβ transcripts, a greater pSmad2–3 response to TGFβ, increased TIMP-1, lower Smad7, increased collagen production and reduced migration ability compared with myofibroblasts from mucosa overlying non-strictured gut. TGFβ blockade increased myofibroblast MMP-12 production and migration, more obviously in myofibroblasts isolated from mucosa overlying non-strictured compared with strictured gut.Conclusions:Changes in TGF-β signalling and MMP production were identified in the mucosa overlying strictures in CD which may give a window into the process of fibrosis.