School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
J Biol Chem. 2024 Feb;300(2):105620. doi: 10.1016/j.jbc.2023.105620. Epub 2024 Jan 3.
Sterile alpha and HEAT/armadillo motif-containing protein (SARM1) was recently described as a NAD-consuming enzyme and has previously been shown to regulate immune responses in macrophages. Neuronal SARM1 is known to contribute to axon degeneration due to its NADase activity. However, how SARM1 affects macrophage metabolism has not been explored. Here, we show that macrophages from Sarm1 mice display elevated NAD concentrations and lower cyclic ADP-ribose, a known product of SARM1-dependent NAD catabolism. Further, SARM1-deficient macrophages showed an increase in the reserve capacity of oxidative phosphorylation and glycolysis compared to WT cells. Stimulation of macrophages to a proinflammatory state by lipopolysaccharide (LPS) revealed that SARM1 restricts the ability of macrophages to upregulate glycolysis and limits the expression of the proinflammatory gene interleukin (Il) 1b, but boosts expression of anti-inflammatory Il10. In contrast, we show macrophages lacking SARM1 induced to an anti-inflammatory state by IL-4 stimulation display increased oxidative phosphorylation and glycolysis, and reduced expression of the anti-inflammatory gene, Fizz1. Overall, these data show that SARM1 fine-tunes immune gene transcription in macrophages via consumption of NAD and altered macrophage metabolism.
无菌α和 HEAT/盔甲状蛋白(SARM1)最近被描述为一种消耗 NAD 的酶,先前已被证明可调节巨噬细胞中的免疫反应。已知神经元 SARM1 通过其 NADase 活性导致轴突退化。然而,SARM1 如何影响巨噬细胞代谢尚未得到探索。在这里,我们表明 Sarm1 小鼠的巨噬细胞显示 NAD 浓度升高,而循环 ADP-核糖(SARM1 依赖性 NAD 分解代谢的已知产物)降低。此外,与 WT 细胞相比,缺乏 SARM1 的巨噬细胞的氧化磷酸化和糖酵解储备能力增加。用脂多糖(LPS)刺激巨噬细胞使其呈促炎状态表明,SARM1 限制了巨噬细胞上调糖酵解的能力,并限制了促炎基因白细胞介素(IL)1b 的表达,但会促进抗炎基因 Il10 的表达。相比之下,我们表明,通过 IL-4 刺激诱导至抗炎状态的缺乏 SARM1 的巨噬细胞显示出氧化磷酸化和糖酵解增加,以及抗炎基因 Fizz1 的表达减少。总体而言,这些数据表明,SARM1 通过消耗 NAD 和改变巨噬细胞代谢来微调巨噬细胞中的免疫基因转录。