Induction of MTHFD2 in Macrophages Inhibits Reactive Oxygen Species–mediated NF-κB Activation and Protects against Inflammatory Responses
Yan Cui, Zihan Li, Lina Ni, Sujun Yu, Xiao Shan, Penghui Hu, Zemin Ji, Weijia Jing, Yanzhao Zhou, Baochen Wang, Hongyuan Dong, Jinxue Zhou, Keliang Xie, Qiujing Yu
Abstract
The one-carbon metabolism enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is critical for cancer cell proliferation and immune cell phenotypes, but whether it can contribute to macrophage inflammatory responses remains unclear. In this study, we show that MTHFD2 was upregulated by LPS in murine macrophages upon activation of the TLR4-MyD88-IKKα/β-NF-κB signaling pathway. MTHFD2 significantly attenuated LPS-induced macrophage proinflammatory cytokine production through its enzymatic activity. Notably, ablation of myeloid MTHFD2 rendered mice more sensitive to septic shock and CCl4-induced acute hepatitis. Mechanistically, MTHFD2 restrained IKKα/β-NF-κB activation and macrophage inflammatory phenotype by scavenging reactive oxygen species through the generation of NADPH. Our study reveals MTHFD2 as a "self-control" mechanism in macrophage-mediated inflammatory responses.