Induction of matrix metalloproteinases-14 and -2 by cyclical mechanical stretch is mediated by tumor necrosis factor-α in cultured human umbilical vein endothelial cells

Objective: Mechanical forces have profound effects on endothelial cells. This study was undertaken to examine the hypothesis that tumor necrosis factor-α (TNF-α) is a potential mediator of stretch-induced effects on matrix metalloproteinase (MMP). Methods: Human umbilical vein endothelial cells (HUVECs) grown on a flexible membrane base were stretched by vacuum to 20% of maximum elongation, at 60 cycles/min. We used the TNF-α monoclonal antibody and c-Jun N-terminal kinase (JNK) inhibitor, SP600125, to investigate the cyclical stretch-induced expression of MMP-14 and -2 in cultured HUVECs. Results: Cyclical mechanical stretch significantly increased protein synthesis and mRNA expression for MMP-14 and -2 from 2 to 24 h. The increased MMP-14 and-2 proteins after stretch were completely blocked after the addition of TNF-α monoclonal antibody (5 μg/ml) or SP600125 (20 μM) 30 min before stretch. By zymography, MMP-2 expression was induced by cyclical stretch and was attenuated by TNF-α monoclonal antibody and SP600125. Cyclical stretch increased the immunohistochemical labeling of MMP-14 and -2 and significantly increased release of TNF-α into the culture media from 120±2 to 331±2 pg/ml (P