Collagenase-1 (MMP-1), matrilysin-1 (MMP-7), and stromelysin-2 (MMP-10) are expressed by migrating enterocytes during intestinal wound healing

Background: Matrix metalloproteinases (MMPs) play a crucial role in wound healing of the skin, airways, and cornea, but data on MMPs in normal intestinal wound healing is limited. The aim of this study was to clarify the role of collagenase-1 (MMP-1), matrilysin-1 (MMP-7), and stromelysin-2 (MMP-10) in intestinal wound repair and to determine the effect of cytokines on the expression of these MMPs in intestinal epithelial cell lines. Methods: Surgical specimens from patients with ischemic colitis (n = 5) were used as an in vivo model of intestinal re-epithelialization. Fetal ileal explants were used as an ex vivo model. In situ hybridization for MMPs -1, -3, -7, and -10 was performed and immunohistochemical stainings were used to localize MMP-7 and -9 expressing cells. Stainings for cytokeratin and laminin-5 were performed to identify epithelial cells and migrating enterocytes, respectively. Caco-2, HT-29, and WiDr cell lines were treated for 6-48 h with different cytokines (e.g. EGF, KGF, IL-1 , TGF-α, TNF-α, and TGF- 1) and Taqman real-time quantitative RT-PCR was used to investigate their effect on the expression of MMPs-1, -7, and -10. Results: MMP-7, MMP-10, and MMP-1 were expressed by migrating enterocytes bordering intestinal ulcers in 5/5, 3/5, and 3/5 samples, respectively. In the fetal gut model, MMP-1 and MMP-10 were expressed by migrating enterocytes, but matrilysin-1 expression was not detected. Matrilysin-1 was up-regulated by TNF-α and IL-1 , and stromelysin-2 by TNF-α and EGF in Caco-2 and WiDr cell cultures. MMP-1 was up-regulated in Caco-2 cells by TGF-beta, EGF, and IL-1 , but only by EGF in WiDR cells. Conclusions: It is concluded that collagenase-1, stromelysin-2, and matrilysin-1 are involved in intestinal re-epithelialization in vivo and that they are up-regulated by cytokines relevant in wound repair.