Return
Tricarboxylic Acid (TCA) Cycle Enzyme Alpha-Ketoglutarate Dehydrogenase (KGDH) as a Nexus for the Regulation of Macrophage Polarization
M
R
DOI:10.1002/jcb.70104.png)
Abstract
En 中文
Macrophage metabolism has been increasingly studied in recent years for its potential as a therapeutic target across multiple pathologies. In this article, we propose that the tricarboxylic acid (TCA) cycle enzyme alpha-ketoglutarate (KG) dehydrogenase (KGDH) serves as a nexus for regulating macrophage polarization toward pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes. This is achieved through modulation of mitochondrial hydrogen peroxide (mtH2O2) and the availability of the TCA cycle metabolites KG and succinate, which are important immunomodulatory molecules. We discuss the evidence showing KGDH is a potent source of mtH2O2 in various cell types and how it could use this reactive oxygen species (ROS) to modulate signaling pathways involved in macrophage differentiation. Coupled to this, we describe emerging evidence showing that KG and succinate exert opposite signaling effects in macrophages, with the former metabolite inducing an anti-inflammatory phenotype and the latter (succinate) promoting inflammation. This occurs through the regulation of dioxygenases involved in hypoxic signaling and epigenetic programming and the activation of G-protein coupled receptor 91 (GPR91) by succinate. Importantly, we contend that regulating KGDH influences the availability of these two metabolites, which, along with controlling mtH2O2 availability, helps control macrophage polarization. Collectively, increased mtH2O2 generation and succinate are known to induce a pro-inflammatory phenotype, whereas low mtH2O2 and high KG have the opposite effect. This suggests that KGDH is a key regulator of macrophage polarization by controlling the availabilities of these immunomodulatory metabolites.
AI Summary
Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.
Journal
IF:
2.8
Papers:
1.1W
Citations:
2.0W
