Pentose Phosphate Shunt Modulates Reactive Oxygen Species and Nitric Oxide Production Controlling Trypanosoma cruzi in Macrophages

• Published in: Frontiers in immunology Vol. 9; p. 202
• Main Authors: Koo, Sue-Jie, Szczesny, Bartosz, Wan, Xianxiu, Putluri, Nagireddy, Garg, Nisha Jain
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 16-02-2018
• Subjects: Animals; Chagas Cardiomyopathy - immunology; Chagas Cardiomyopathy - parasitology; Disease Models, Animal; Host-Parasite Interactions - immunology; Humans; Immunology; Interferon-gamma - immunology; macrophages; Macrophages - immunology; Macrophages - parasitology; metabolism; Mice; Mice, Knockout; NADPH; Nitric Oxide - immunology; Nitric Oxide - metabolism; Pentose Phosphate Pathway - immunology; peroxisome proliferator-activated receptors; PPAR alpha - genetics; PPAR alpha - immunology; Primary Cell Culture; RAW 264.7 Cells; reactive oxygen species; Reactive Oxygen Species - immunology; Reactive Oxygen Species - metabolism; Trypanosoma cruzi; Trypanosoma cruzi - immunology; Up-Regulation; NADPH; macrophages; peroxisome proliferator-activated receptors; reactive oxygen species; metabolism; pentose phosphate pathway; Trypanosoma cruzi
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2018.00202

Metabolism provides substrates for reactive oxygen species (ROS) and nitric oxide (NO) generation, which are a part of the macrophage (Mφ) anti-microbial response. Mφs infected with
(
) produce insufficient levels of oxidative species and lower levels of glycolysis compared to classical Mφs. How Mφs fail to elicit a potent ROS/NO response during infection and its link to glycolysis is unknown. Herein, we evaluated for ROS, NO, and cytokine production in the presence of metabolic modulators of glycolysis and the Krebs cycle. Metabolic status was analyzed by Seahorse Flux Analyzer and mass spectrometry and validated by RNAi.
infection of RAW264.7 or bone marrow-derived Mφs elicited a substantial increase in peroxisome proliferator-activated receptor (PPAR)-α expression and pro-inflammatory cytokine release, and moderate levels of ROS/NO by 18 h. Interferon (IFN)-γ addition enhanced the
-induced ROS/NO release and shut down mitochondrial respiration to the levels noted in classical Mφs. Inhibition of PPAR-α attenuated the ROS/NO response and was insufficient for complete metabolic shift. Deprivation of glucose and inhibition of pyruvate transport showed that Krebs cycle and glycolysis support ROS/NO generation in
 + IFN-γ stimulated Mφs. Metabolic profiling and RNAi studies showed that glycolysis-pentose phosphate pathway (PPP) at 6-phosphogluconate dehydrogenase was essential for ROS/NO response and control of parasite replication in Mφ. We conclude that IFN-γ, but not inhibition of PPAR-α, supports metabolic upregulation of glycolytic-PPP for eliciting potent ROS/NO response in
infected Mφs. Chemical analogs enhancing the glucose-PPP will be beneficial in controlling
replication and dissemination by Mφs.