Figure 5.

Enhanced glycolysis in activated monocytes and macrophages is related to SLC7A5-mediated amino acid (AA) influx. (A) Real-time extracellular acidification rate (ECAR), glycolysis, and glycolysis capacity in monocytes stimulated with 100 ng/ml LPS for 24 h in the absence or present of BCH (50 mM). ECAR levels were measured following sequential treatments with glucose (10 mM), oligomycin (2 µM), and 2-DG (50 mM). Glycolysis and glycolysis capacity were calculated by subtracting ECAR after glucose treatment from ECAR before oligomycin and subtracting ECAR after oligomycin from ECAR before 2-DG treatment, respectively. (B) Cellular glycolysis and glycolysis capacity in LPS-stimulated monocytes with or without BCH (50 mM). Monocytes from four different donors were independently tested in at least four technical replicates. (C–F) Real-time ECAR, glycolysis, and glycolysis capacity in macrophages stimulated with 100 ng/ml LPS for 24 h in the absence or presence of BCH (50 mM) or JPH203 (10 µM). ECAR levels were measured as described in (A). Monocyte-derived macrophages from three to five different donors were independently tested in at least four technical replicates. (G) Real-time ECAR and OCR measurement in LPS-stimulated macrophages replenished with 50 µg/ml leucine in XF assay media. Macrophages were stimulated with LPS for 24 h and were incubated in HBSS for 1 h to deplete AAs. ECAR and OCR levels were measured as described in (A). Data are representative of three independent experiments with three different donors. Bar graphs show the mean ± SEM. *p < 0.05 and **p < 0.01 by two tailed paired t-test.