MCT2 mediates concentration-dependent inhibition of glutamine metabolism by MOG

Abstract

α-Ketoglutarate (αKG) is a key node in many important metabolic pathways. The αKG analogue N -oxalylglycine (NOG) and its cell-permeable pro-drug dimethyloxalylglycine (DMOG) are extensively used to inhibit αKG-dependent dioxygenases. However, whether NOG interference with other αKG-dependent processes contributes to its mode of action remains poorly understood. Here we show that, in aqueous solutions, DMOG is rapidly hydrolysed to yield methyloxalylglycine (MOG). MOG elicits cytotoxicity in a manner that depends on its transport by monocarboxylate transporter 2 (MCT2) and is associated with decreased glutamine-derived TCA-cycle flux, suppressed mitochondrial respiration and decreased ATP production. MCT2-facilitated entry of MOG into cells leads to sufficiently high concentrations of NOG to inhibit multiple enzymes in glutamine metabolism, including glutamate dehydrogenase (GDH). These findings reveal that MCT2 dictates the mode of action of NOG by determining its intracellular concentration, and have important implications for the use of (D)MOG in studying αKG-dependent signalling and metabolism.

Serine and 1-carbon metabolism are required for HIF-mediated protection against retinopathy of prematurity

“…The liver selectivity of DMOG is likely a consequence of DMOG's instability and inability to survive intact after a first pass through the liver. In cell culture, DMOG is rapidly hydrolyzed to either n-oxalylglycine or methyl oxalylglycine (31). To prove that DMOG does not enter plasma, we used LC-MS/MS to analyze plasma from animals treated with either DMOG or RXD injected i.p.…”

Modeling succinate dehydrogenase loss disorders in C. elegans through effects on hypoxia-inducible factor

“…elegans , we studied egg-laying behavior in the presence of dimethyloxalylglycine (DMOG), a cell-permeable succinate analog. DMOG is the prodrug of N-oxalylglycine (NOG), which is known to inhibit 2-ketoglutarate-dependent dioxygenases but is unable to permeate cell membranes [35]. Previous studies have shown that mammalian cells treated with DMOG show an increase in transcription of HIF-1-responsive genes [36].…”

The mechanism and role of intracellular α-ketoglutarate reduction in hepatic stellate cell activation

“…Although it has been reported some channel proteins and metabolic enzymes including IDH1, IDH2, BCAT1, OGDH, GDH, SLC1A4, SLC1A5, GLUL, and GLA were involved in the metabolism of α-ketoglutarate in many cell types [9,[23][24][25][26][27][28][29][30][31], the mechanism of intracellular α-ketoglutarate regulation during HSC activation has not been previously reported. The main metabolic sources of intracellular α-ketoglutarate including glucose and glutamine were kept sufficient in the cell culture medium in our research [32,33], while the expression of channel proteins and metabolic enzymes mentioned above were investigated during HSC activation.…”