Authors: Yuko Yamamoto Tomohiro Osanai Fumie Nishizaki Takanori Sukekawa Kei Izumiyama Shigeki Sagara Ken Okumura
Publish Date: 2012/01/11
Volume: 27, Issue: 6, Pages: 624-633
Abstract
Matrix metalloproteinase MMP9 plays an important role in cardiovascular events However the mechanisms underlying in vivo activation of MMP9 are largely unknown We investigated the secretion and activation of MMP9 under a celltocell interaction and the effects of hypoxia and cytokine Human umbilical vein endothelial cell HUVEC and THP1 human monocyte cell line were cultured individually or cocultured under normoxic and hypoxic conditions In a coculture of HUVEC and THP1 proMMP9 secretion was increased twofold compared with individual culture of HUVEC and THP1 whereas MMP2 secretion was unchanged The increase in proMMP9 secretion was suppressed by antiadhesion molecule antibodies and mitogenactivated protein kinase inhibitors PD98059 MAPK/ERK kinase1 inhibitor and SP600125 Jun Nterminal kinase inhibitor ProMMP9 secretion was increased by tumor necrosis factor TNFα at 50 ng/ml P 005 but was not activated under normoxic 20 conditions ProMMP9 in coculture was activated under hypoxic 1 conditions and was potentiated by TNFα both P 005 To further investigate the mechanism of hypoxiainduced MMP9 activation heat shock protein Hsp90 which was suggested to be related to MMP9 activation was measured by Western blot analysis The ratio of Hsp90 to glyceraldehyde3phosphate dehydrogenase was increased in hypoxic 1 coculture conditions with TNFα P 005 Treatment with geldanamycin and 17DMAG Hsp90 inhibitor suppressed the active form of MMP9 Celltocell interaction between endothelial cells and monocytes promotes proMMP9 synthesis and secretion Hypoxia and inflammation are suggested to play an important role in activating proMMP9 presumably via Hsp90
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