Study of the modulation of HIF-1alpha and NF-kB on macrophage glucose metabolism and pro-inflammatory profile

• Grant number: 22/13610-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2023
• Status: Discontinued
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Pedro Manoel Mendes de Moraes Vieira
• Grantee: Guilherme Ribeiro da Silva
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 20/16030-0 - Immunometabolic adaptation of tissue resident macrophages in health and disease, AP.TEM
• Associated scholarship(s): 24/04635-5 - Pentose phosphate pathway and NAPDH-oxidase-derived ROS over the control of inflammasome activation in pro-inflammatory macrophages, BE.EP.MS

Abstract

Pro-inflammatory macrophages, as those activated with LPS and INF-³ (³), are characterized by NF-ºB activation, pro-inflammatory cytokine induction (IL-1, IL-6, IL-12, TNF-±), and nitric oxide (NO) and reactive oxygen species (ROS) production. One source of ROS rapidly activated in phagocytes is NADPH-oxidase, regulated by NF-ºB, which directly controls gp91phox gene expression. M(LPS/³) macrophages acquire a high glycolytic metabolism in order to exert their efector functions. Hypoxia inducible factor-1± (HIF-1±) has a key role on macrophage metabolism. HIF-1± is a cell constitutively expressed-transcription factor, but it is degraded by the proteasome system during normoxia. M(LPS/³) macrophages has HIF-1±-degradation pathway inhibited by mitochondrial ROS (mtROS) production, by reverse electron transport (RET) on the electron transport chain (ETC) even during normoxia. Together with NF-ºB, stabilized HIF-1± induces glucose metabolism associated genes. Pentose phosphate pathway is upregulated in inflammatory macrophages, generating NADPH as substrate for NADPH-oxidase. In this context, mitochondrial glycerol-3-phosphate dehydrogenase enzyme (GPD2) inputs electron into ETC and it has na important role in glycolytic flux maintenance in activated macrophages. However, it is not described wether GPD2 contributes to mtROS production and HIF-1± stabilization in M(LPS/³) macrophages. As glucose metabolism enzimes, PPP and GPD2 are regultaed by NF-ºB and HIF-1±, we hypothesized that NF-ºB and HIF-1± controls glucose metabolism and ROS production in M(LPS/³) macrophages through NADPH-oxidase and GPD2 activity. These two ROS sources would be able to stabilize HIF-1±, to sustain its stabilization, and ensure macrophage efector function. Our preliminar data suggest that HIF-1± binds directly to NF-ºB, optimizing NF-ºB activation. HIF-1±-macrophage deletion reduces expression of gp91phox, Gpd2 and glucose metabolism and PPP related genes. Furthermore, NADPH-oxidase derived ROS is related to HIF-1± stabilization and NF-ºB activation, suggesting na activation feedback in ROS-HIF-1±-NF-ºB axis. Together, the understanding of the mechanisms involved in HIF-1± stabilization in inflammatory macrophages can elucidate the action of these cells in inflammatory contexts.