Epinephrine-induced MMP expression is different between skeletal fibroblasts and myoblasts

Skeletal fibroblasts and myoblasts are among the cell types currently being considered in cell therapy for ischaemic heart disease. To investigate whether the expression of the tissue-remodelling proteolytic enzymes matrix metalloproteinases (MMPs) and the cellular energy regulator AMP-activated protein kinase (AMPK) is comparable between the two cell lines in response to epinephrine treatment, mouse skeletal fibroblasts (NOR-10) and myoblasts (C2C12) were treated with or without a low (11 nmol.l(-1)) or high (55 nmol.l(-1)) dose of epinephrine for 2 or 6h. Cellular MMP-3 expression was increased by the high-dose epinephrine at both treatment periods in both cell lines. Cellular MMP-2 and MMP-13 expressions were amplified by the 2- or 6-h epinephrine incubation in fibroblasts. However, in myoblasts, such an increase was only seen at the longer treatment time. An elevated AMPK alpha expression was observed after a 2-h presence of epinephrine in both cell lines, which matches temporally with the early increased cellular MMP-2 and MMP-13 expression in fibroblasts. Activity of secreted MMP-2 increased only after 6-h epinephrine treatment in both cell types. Our data suggest that skeletal fibroblasts respond earlier to epinephrine application in terms of endogenous synthesis of the proteolytic and the energy homeostasis enzymes, whereas such response occurs later and to a milder dose of the beta adrenergic agonist in myoblasts. Copyright (C) 2011 John Wiley & Sons, Ltd.