Hypoxia-increased RAGE expression regulates chemotaxis and pro inflammatory cytokines release through nuclear translocation of NF-κ B and HIFI α in THP-1 cells

The potential role of hypoxia in mediating the receptor for advanced glycation end products (RAGE) expression deserves to be confirmed. And the role of RAGE in hypoxia-induced chemotaxis and inflammation is still unclear. In present study, THP-1 cells were pretreated with siRNA to block HIFI cc,NF-kappa B, or RAGE, followed by exposed to hypoxia (combined with H2O2 or SNP), and then RAGE expression, nuclear translocation of HIFI cc and NF-kappa B, release of TNF-alpha and IL-1 beta, as well as expression of MCP-1 and CCR2 were measured. The results revealed that RAGE mRNA and protein in THP-1 cells were significantly increased after exposed into hypoxia atmosphere, especially into the solution containing SNP or H2O2. Moreover, SNP or H2O2 exposure could further amplify hypoxia-induced nuclear translocation of HIF-1 alpha and NF-kappa B. Knockdown HIF-1 alpha or NF-kappa B by siRNAs could reduce hypoxia-and oxidative stress-induced RAGE hyper-expression. And pretreatment THP-1 cells with RAGE siRNA or NF-kappa B siRNA could reduce hypoxia- and oxidative stress-induced expression of MCP-I and CCR2, and release of TNF-alpha and IL-1 beta. Thus, hypoxia not only increases RAGE expression in THP-1 cells by promoting nuclear translocation of NF-kappa B and HIFI alpha, but also regulates chemotaxis and pro-inflammatory cytokines release, which may be partially mediated through upregulation of RAGE expression. (C) 2017 Elsevier Inc. All rights reserved.