title: Disruption of the Hedgehog signaling pathway in inflammatory bowel disease fosters chronic intestinal inflammation.
abstract: Hedgehog (Hh) signaling is essential for intestinal homeostasis and has been associated with inflammation and tissue repair. We hypothesized that Hh signaling could affect the inflammatory process in inflammatory bowel disease (IBD). For this purpose, colon specimens from the inflamed and non-inflamed mucosa of 15 patients with Crohn's disease (CD), 15 with ulcerative colitis, and 15 controls were analyzed by immunohistochemistry and real-time PCR. The production and modulation of cytokines were measured by ELISA from culture explants. Apoptosis was assessed by TUNEL and caspase-3 activity assays. Chemotaxis was evaluated using a transwell system. Primary human intestinal and skin fibroblasts were used for analyzing migration and BrdU incorporation. Hh proteins were generally expressed at the superficial epithelium, and a marked reduction was observed in CD. In the lamina propria, Gli-1 predominantly co-localized with vimentin- and alpha-smooth muscle actin-positive cells, with lower levels observed in CD. In colon explants, Hh stimulation resulted in reduction, while blockade increased, TNF α, IL-17, and TGF β levels. Apoptotic rates were higher in inflamed samples, and they increased after Hh blockade. Levels of Gli-1 mRNA were negatively correlated with caspase-3 activity. Hh blockade increased chemoattraction of monocytes. Primary fibroblasts incorporated more BrdU, but migrated less after Hh blockade. These results suggest that Hh signaling provides a negative feedback to the lamina propria, down-regulating inflammatory cytokines, and inhibiting leukocyte migration and fibroblast proliferation, while favoring fibroblast migration. Therefore, Hh signaling is strongly implicated in the pathogenesis of intestinal inflammation, and it may represent a novel therapeutic target for IBD.
authors.affiliation: Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Buongusto
authors.affiliation: Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bernardazzi
authors.affiliation: Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil.
authors.forename: Agnes N
authors.initials: AN
authors.lastname: Yoshimoto
authors.affiliation: Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil.
authors.forename: Hayandra F
authors.initials: HF
authors.lastname: Nanini
authors.affiliation: Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil.
authors.forename: Raquel L
authors.initials: RL
authors.lastname: Coutinho
authors.affiliation: Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil.
authors.forename: Antonio Jose V
authors.initials: AJV
authors.lastname: Carneiro
authors.affiliation: Laboratório de Imunologia Celular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil.
authors.forename: Morgana T
authors.initials: MT
authors.lastname: Castelo-Branco
authors.affiliation: Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil. heitor.souza@gmail.com.|D'Or Institute for Research and Education (IDOR), Rio de Janeiro, 22281-100, Brazil. heitor.souza@gmail.com.
authors.forename: Heitor S
authors.identifier: http://orcid.org/0000-0002-3647-7324
authors.initials: HS
authors.lastname: de Souza
mesh_terms: D000328:Adult; D003106:Colon / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D053823:Hedgehog Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000473:pathology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D055815:Young Adult
chemical_list: D053823:Hedgehog Proteins
keywords: Crohn’s disease; Epithelial cell apoptosis; Hedgehog signaling pathway; Inflammatory bowel disease