Regulation of Matrix Metalloproteinase 2 by AMP-Dependent Kinase

Abstract

Purpose: : Metalloproteinase (MMP) 2 is a gelatinase that degrades a broad range of collagens, elastin and fibronectin. MMP2 plays an important role in angiogenesis; however, the mechanisms regulating MMP2 activity are not fully understood.AMP-dependent Kinase (AMPK) is a primary sensor of cellular energy change. AMPK regulates energy homeostasis by switching off ATP-consuming biosynthetic pathways and protects cells from metabolic or nutritional stress. Recently, AMPK was reported to stimulate angiogenesis. We investigated whether AMPK regulates the activity of MMP2.

Methods: : AMPK wild type (WT) and AMPK1-/-2-/- (KO) mouse embryonic fibroblasts (MEFs) were grown in Dulbecco’s modified Eagle’s medium / F12 with 10% heat inactivated fetal bovine serum. After culture for 24 hours in serum-free medium, MEFs were stimulated with interleukin-1β (IL1-β, 0.5-20 ng/ml) or tumor necrosis factor (TNF, 1-200 ng/ml). After 24 hours, media was evaluated by gelatin zymography normalized by protein concentration of cell extracts. Results of zymography were quantified using Image J software for relative area measurements. Data are expressed as a percent of the area obtained from the untreated control group.

Results: : In WT MEFs, both IL1-β (1 and 5 ng/ml) and TNF (5 and 10 ng/ml) significantly increased the activity of MMP2 in a dose-dependent manner (135%, p<0.05; 158%, p<0.01; 121%, p<0.05; 133%, p<0.01 respectively).Compared to the WT MEFs, MMP2 activity in KO MEFs was significantly lower when stimulated by IL-1β (5 ng/ml) (158% in WT vs 113% in KO, p<0.05) and further decreased after TNF (5 ng/ml) stimulation (121% in WT vs 88% in KO, p<0.05).

Conclusions: : AMPK appears to increase activity of MMP2 following stimulation with inflammatory cytokines.

Keywords: extracellular matrix