Lipopolysaccharide (LPS) induces matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) in bovine dermal fibroblasts

Abstract

Bovine digital dermatitis (BDD) is one of the most important problems in dairy herds. The exact etiology is unknown but it is believed that bacteria have cardinal roles. Matrix metalloproteinases (MMPs) are a group of enzymes responsible for the degradation of extracellular matrix proteins. The plausible role of these enzymes in the formation of ulcerative lesions in various tissues in humans is widely known. Ulcers on the plantar skin of hind feet are the prominent lesions in early stage of BDD. The main objective of this study was to determine whether MMP-2 and -9 enzymes are enhanced following LPS challenge in bovine dermal fibroblasts. Skin samples were obtained from two Holstein -Friesian cows after slaughtering. Primary bovine dermal fibroblasts were isolated from foot skin and then exposed to 5 g/ml LPS. As result, we found that LPS stimulates the release of MMP-2 and MMP-9 enzymes in bovine dermal fibroblasts. When compared with controls, immunoblots revealed significant increase in MMP-2 (by 56%, P<0.005) and MMP-9 (by 74%, P<0.005) enzymes. Zymographic analyses demonstrated LPS challenge resulted with the release of higher amount of active MMP-2 and 9 enzymes by 37% and 48%, respectively. These data indicate LPS may be an important factor in the pathogenesis of BDD by causing local MMP-2 and MMP-9 enzyme release.