Figure 1. Hyperoxic exposure increases glycolysis in cultured lung ECs.

(A–C, E, and F) Primary LMVECs (A–C, and F) and MFLM-91U cells (E) were exposed to hyperoxia for 24 hours and then cultured in normoxia for 24 hours (refers to O₂). (A) ECAR was measured in cells by the Seahorse XF24 Analyzer. Kinetic ECAR response to glucose (Glc), oligomycin (Oligo), and 2-DG was recorded. Basal glycolysis and glycolytic capacity were calculated after normalization into the number of live cells. n = 32 in air and n = 16 in hyperoxia. (B) Glycolytic rate assay was performed to determine glycolysis-derived proton efflux. n = 32 in air and n = 16 in hyperoxia. (C) Intracellular lactate was measured using the L-lactate Assay kit. n = 7 per group. (D) Schematic figure showing the production of [2,3-¹³C]lactate and [3-¹³C]lactate from [1,2-¹³C]glucose via glycolysis and the PPP, respectively. (E) [2,3-¹³C]lactate was measured by the NMR when cells were incubated with [1,2-¹³C]glucose (20 mM) for 24 hours during air recovery phase. n = 4 per group. (F) Detectable intracellular metabolites during glycolysis were presented. n = 4 in air and n = 6 in hyperoxia. Data are expressed as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 versus air using 1-railed t test (A–C, E, and F).