Heme oxygenase-1-dependent and -independent regulation of angiogenic genes expression: effect of cobalt protoporphyrin and cobalt chloride on VEGF and IL-8 synthesis in human microvascular endothelial cells.
Induction of heme oxygenase-1 (HO-1) expression can be achieved by stimulation with cobalt protoporphyrin (CoPPIX) or cobalt chloride (CoCl2). HO-1 has been recently implicated in regulation of angiogenesis and CoCl2 is known to potently activate hypoxia inducible factor-1 (HIF-1) transcription factor, a key regulator of angiogenic response in hypoxia. Here we determined the effect of CoPPIX and CoCl2 on the expression of vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8), the two major angiogenic mediators, in human microvascular endothelial cells (HMEC-1). CoPPIX induced HO-1 expression and strongly enhanced VEGF and IL-8 synthesis, through the activation of VEGF and IL-8 promoters. Inhibition of HO activity by SnPPIX decreased VEGF production, while, interestingly, it did not affect IL-8. CoCl2 activated hypoxia-responsive element (HRE) and consequently VEGF generation via the enhancement of production of reactive oxygen species (ROS). On the other hand, CoCl2 did not influence IL-8 expression, while CoPPIX did not induce ROS elevation neither it affected HRE activity in VEGF promoter. Our data show that although both CoCl2 and CoPPIX induce HO-1, the influence of CoCl2 on VEGF does not involve HO-1 and is HIF-1-dependent, while the effect of CoPPIX does not involve HIF-1 but relies on HO-1.
Loboda
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A
Department of Medical Biotechnology, Faculty of Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland.
Jazwa
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A
Wegiel
B
B
Jozkowicz
A
A
Dulak
J
J
D002478:Cells, Cultured; D003035:Cobalt / Q000494:pharmacology*; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis*; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics*; D011524:Protoporphyrins / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
D016209:Interleukin-8; D011524:Protoporphyrins; D042461:Vascular Endothelial Growth Factor A; D003035:Cobalt; C007095:cobaltiprotoporphyrin; D051547:Heme Oxygenase-1; C018021:cobaltous chloride