title: Functional relevance of activin A in the intestinal epithelium.
abstract: BACKGROUND
  Activin A modulates inflammation and repair in various tissues. The aim of this study was to characterize the effects of activin A on intestinal epithelial cell function and to evaluate a potential role in intestinal epithelial wound repair and inflammation.
  
  
  METHODS
  The expression of activin A and its receptors ActRI and ActRII in intestinal epithelial IEC-6 cells and in tissues from IBD patients and non-inflamed controls was evaluated using RT-PCR and immunohistochemistry. Functional effects of activin A on intestinal epithelial cell migration and proliferation were assessed using an in vitro wounding model and colorimetric MTT assays.
  
  
  RESULTS
  Expression of the activin betaA subunit and the activin receptors ActRI and ActRII in IEC-6 cells was demonstrated using RT-PCR. Activin A (50 ng/ml) caused a significant, on average 2.8-fold enhancement of epithelial cell migration and a significant on average 4.1-fold inhibition of IEC-6 cell proliferation. Expression of ActRI and ActRII was observed in all intestinal tissues from patients with IBD and in all controls. In contrast, no expression of the activin betaA-subunit was observed in controls, while betaA expression was found in intestinal tissues from IBD patients.
  
  
  CONCLUSIONS
  Activin A may play an important role in the modulation of intestinal epithelial cell function, thus providing a new approach to modulate intestinal wound repair.
authors.affiliation: Department of Hepatology and Gastroenterology, Charité Medical School, Campus Virchow Clinic, Berlin, Germany. axel.dignass@charite.de
authors.forename: A U
authors.initials: AU
authors.lastname: Dignass
authors.forename: S
authors.initials: S
authors.lastname: Jung
authors.forename: J
authors.initials: J
authors.lastname: Harder-d'Heureuse
authors.forename: B
authors.initials: B
authors.lastname: Wiedenmann
mesh_terms: D029404:Activin Receptors / Q000032:analysis / Q000235:genetics; D028341:Activins / Q000235:genetics / Q000502:physiology*; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002455:Cell Division; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D003106:Colon / Q000473:pathology; D005434:Flow Cytometry; D019073:HT29 Cells; D006801:Humans; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000473:pathology; D028322:Inhibin-beta Subunits / Q000235:genetics / Q000502:physiology*; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014945:Wound Healing / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; C422405:activin A; D028341:Activins; D028322:Inhibin-beta Subunits; D029404:Activin Receptors