Hypoxia enhances secretion of matrix metalloproteinases in bovine dermal fibroblasts: An in vitro approach to bovine digital dermatitis

Abstract

Dermal fibroblasts are of great importance in skin homeostasis. They are responsible for the synthesis and remodelling of extracellular proteins by the way of synthesis of some specific kind of Matrix Metalloproteinases (MMPs). Imbalance between MMPs and their tissue inhibitors (TIMPs) are known to involve ulcerative wounds in many tissues, including skin. In veterinary medicine, bovine digital dermatitis (BDD) is an ulcerative skin disorder of dairy cattle. To date, Koch's postulate has not yet been fulfilled for the pathogenesis. In present study, we tested in vitro role of hypoxia if it evokes a response in MMP-1, MMP-2 and MMP-13 enzymes and their inhibitors in bovine dermal fibroblasts. Dermal fibroblasts were exposed to hypoxia in various time periods (6, 12 and 24 h). Immunoblotting revealed 6-, 12- and 24-h hypoxia, which resulted in 43.5%, 75% and 65% increase in MMP-1, 76%, 61% and 55% increase in MMP-2 and 80%, 78% and 55% increase in MMP-13 enzymes levels, respectively. We observed slight increases in TIMP-1 and TIMP-2 enzymes, but differences between treatment and control groups did not show any statistical significance. Our findings indicate that hypoxia induces MMP-1, MMP-2 and MMP-13 enzymes and may contribute to pathogenesis of BDD through in the development of in vivo lesions.