Figure 4. Kinetic isotope effect minimally affects [3-2H]glucose and [4-2H]glucose metabolism.
A) [3-2H]glucose was titrated with unlabeled glucose and added to H1299 cells expressing mtIDH1-C. Contribution from [3-2H]glucose to lipogenic NADPH (left panel, normalized to contribution at 100% [3-2H]glucose media enrichment) and 2HG (right panel) was measured. Dashed lined (left panel) represents 1:1 contribution of [3-2H]glucose to lipogenic NADPH to enrichment of [3-2H]glucose in media. B) [4-2H]glucose was titrated with unlabeled glucose and added to H1299 cells expressing mtIDH2-M. Labeling from [4-2H]glucose on lactate and malate (left panel); aspartate, citrate, and fumarate (middle panel); and 2HG (right panel) was measured. C) [3-2H]glucose was titrated with unlabeled glucose in HT1080 cells harbouring endogenous IDH1 mutations (R132C/+). Contribution from [3-2H]glucose to lipogenic NADPH (left panel, normalized to contribution at 100% [3-2H]glucose media enrichment) and M1 labeling on 2HG (right panel) was quantified at 0, 25, 50, 75, and 100 percent dilution with unlabeled glucose (left panel) in HT1080 cells cultured with [3-2H]glucose diluted with unlabeled glucose at 0, 25, 50, 75, and 100 percent enrichment. Data presented are shown as mean ± SD of three biological replicates for panels A (right panel), B, and C (right panel). Data represent mean ± 95% confidence interval for at least three biological replicates for panels A (left panel) and C (left panel)