Activated macrophages switch from oxidative phosphorylation to aerobic glycolysis, similar to the Warburg effect, presenting a potential therapeutic target in inflammatory disease. The endogenous metabolite itaconate has been reported to regulate macrophage function, but its precise mechanism is not clear. Here, we show that 4-octyl itaconate (4-OI, a cell-permeable itaconate derivative) directly alkylates cysteine residue 22 on the glycolytic enzyme GAPDH and decreases its enzyme activity. Glycolytic flux analysis by U13C glucose tracing provides evidence that 4-OI blocks glycolytic flux at GAPDH. 4-OI thereby downregulates aerobic glycolysis in activated macrophages, which is required for its anti-inflammatory effects. The anti-inflammatory effects of 4-OI are replicated by heptelidic acid, 2-DG and reversed by increasing wild-type (but not C22A mutant) GAPDH expression. 4-OI protects against lipopolysaccharide-induced lethality in vivo and inhibits cytokine release. These findings show that 4-OI has anti-inflammatory effects by targeting GAPDH to decrease aerobic glycolysis in macrophages.

中文翻译：

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衣康酸4-辛酯通过靶向GAPDH发挥抗炎作用，从而抑制有氧糖酵解。

活化的巨噬细胞从氧化磷酸化转变为有氧糖酵解，类似于Warburg效应，为炎症性疾病提供了潜在的治疗靶标。据报道内康代谢衣康酸可调节巨噬细胞功能，但其确切机制尚不清楚。在这里，我们显示了衣康酸4-辛基酯（4-OI，可渗透细胞的衣康酸酯衍生物）直接将糖酵解酶GAPDH上的半胱氨酸残基22烷基化，并降低了其酶活性。通过U13C葡萄糖追踪进行的糖酵解通量分析提供了证据，表明4-OI在GAPDH处阻断了糖酵解通量。因此4-OI下调活化巨噬细胞中的有氧糖酵解，这是其抗炎作用所必需的。庚二酸可复制4-OI的抗炎作用，2-DG，并通过增加野生型（但不是C22A突变体）GAPDH表达而逆转。4-OI可防止体内脂多糖诱导的致死性并抑制细胞因子的释放。这些发现表明4-OI通过靶向GAPDH以减少巨噬细胞中的需氧糖酵解而具有抗炎作用。