Pentose phosphate pathway and NAPDH-oxidase-derived ROS over the control of inflammasome activation in pro-inflammatory macrophages

• Grant number: 24/04635-5
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: August 22, 2024
• End date: February 21, 2025
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Pedro Manoel Mendes de Moraes Vieira
• Grantee: Guilherme Ribeiro da Silva
• Supervisor: Charles Evavold
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Massachusetts General Hospital, United States
• Associated to the scholarship: 22/13610-0 - Study of the modulation of HIF-1alpha and NF-kB on macrophage glucose metabolism and pro-inflammatory profile, BP.MS

Abstract

The recognition of bacterial components by macrophages triggers the production of inflammatory mediators, such as hydrogen peroxide (ROS), and cytokines, including TNF-a, IL-6, and IL-1b. This profile can be induced in macrophages activated with LPS plus IFN-a (M(LPS/y)) and depends on glucose metabolism and stabilization of hypoxia inducible factor-1a (HIF-1a). Glucose is necessary for NADPH production via pentose phosphate pathway (PPP), and NADPH is the substrate for ROS production by NADPH-oxidase complex (NOX). Beyond that, M(LPS/y) macrophages produce mitochondrial ROS (mtROS) as consequence of metabolic rewiring. Both NOX-derived ROS and mtROS have signaling functions and are involved in cytokine production. For example, mtROS may control inflammasome activation, which enables IL-1b maturation and release through Gasdermin D (GSDMD) pores at plasma membrane. GSDMD oligomerization depends on inflammasome activation and mtROS. However, whether other sources of ROS control these processes in M(LPS/y) macrophages are not well understood. Our data indicates that HIF-1a controls glucose flux through PPP, which controls ROS production via NOX and IL-1b gene expression. Thus, we hypothesized that NOX-derived ROS, beyond controlling Il-1b levels, controls inflammasome activation in M(LPS/y) macrophages. To test our hypothesis, PPP NAPDH-generating enzymes and gp91phox subunit of NOX will be depleted in macrophages, and markers of inflammasome activation will be measured.