title: Cathepsin B release from rodent intestine mucosa due to mechanical injury results in extracellular matrix damage in early post-traumatic phases.
abstract: An in vivo model was used to investigate the role of cathepsins in mouse intestine after mechanical manipulation. Inspection of different intestine segments by immunofluorescence microscopy provided evidence for a local release of cathepsin B from cells of individual gut sections shortly after traumatic injury. Densitometry of immunoblots ruled out alterations in cathepsin B expression levels. Because similar results were obtained with both mouse and rat intestine trauma models, we were interested in identifying potential targets of released cathepsin B in early post-traumatic phases. Immunoblotting revealed initial declines followed by an increase in protein levels of claudin-1 and E-cadherin, indicating that tight junctions and cell-cell adhesions were only transiently compromised by surgical trauma. Apical aminopeptidase N and dipeptidyl peptidase IV were only slightly affected, whereas basolateral low-density lipoprotein receptors were strongly up-regulated in response to trauma. As potential targets of cathepsin B released from injured cells, we identified collagen IV and laminin of the basement membrane that was damaged during initial post-traumatic stages. Because increased collagen IV expression was observed in the intestine of cathepsin B-deficient animals, we propose a direct role of cathepsin B in that it contributes to acute post-traumatic extracellular matrix damage and may thereby facilitate onset of post-operative ileus.
authors.affiliation: School of Engineering and Science, Jacobs University Bremen, Campus Ring 6, D-28759 Bremen, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Vreemann
authors.forename: Hong
authors.initials: H
authors.lastname: Qu
authors.forename: Kristina
authors.initials: K
authors.lastname: Mayer
authors.forename: Louise Bjorkholt
authors.initials: LB
authors.lastname: Andersen
authors.forename: M Irina
authors.initials: MI
authors.lastname: Stefana
authors.forename: Sven
authors.initials: S
authors.lastname: Wehner
authors.forename: Mariola
authors.initials: M
authors.lastname: Lysson
authors.forename: Anca M
authors.initials: AM
authors.lastname: Farcas
authors.forename: Christoph
authors.initials: C
authors.lastname: Peters
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinheckel
authors.forename: Jörg
authors.initials: J
authors.lastname: Kalff
authors.forename: Klaudia
authors.initials: K
authors.lastname: Brix