Metabolite

Cell biology

Biology

Glycolysis

Pentose phosphate pathway

Oxidase test

Small molecule

Pentose

Metabolism

Biochemistry

Phosphate

Computational biology

Genetics

Immune system

NAD+ kinase

Nicotinamide adenine dinucleotide phosphate

Oxidative phosphorylation

Enzyme

Dehydrogenase

Respiratory burst

Chemistry

Fermentation

Glucose-6-phosphate dehydrogenase

Nature Chemical Biology

Glucose is catabolized by two fundamental pathways, glycolysis to make ATP and the oxidative pentose phosphate pathway to make reduced nicotinamide adenine dinucleotide phosphate (NADPH). The first step of the oxidative pentose phosphate pathway is catalyzed by the enzyme glucose-6-phosphate dehydrogenase (G6PD). Here we develop metabolite reporter and deuterium tracer assays to monitor cellular G6PD activity. Using these, we show that the most widely cited G6PD antagonist, dehydroepiandosterone, does not robustly inhibit G6PD in cells. We then identify a small molecule (G6PDi-1) that more effectively inhibits G6PD. Across a range of cultured cells, G6PDi-1 depletes NADPH most strongly in lymphocytes. In T cells but not macrophages, G6PDi-1 markedly decreases inflammatory cytokine production. In neutrophils, it suppresses respiratory burst. Thus, we provide a cell-active small molecule tool for oxidative pentose phosphate pathway inhibition, and use it to identify G6PD as a pharmacological target for modulating immune response. Identification of an improved glucose-6-phosphate dehydrogenase (G6PD) inhibitor G6PDi-1 blocks G6PD activity more robustly than the widely cited antagonist DHEA. G6PDi-1 treatment blocks T cell cytokine production and neutrophil oxidative burst.

A small molecule G6PD inhibitor reveals immune dependence on pentose phosphate pathway