Figure 4. Glycolysis is impaired in PKM2 knockdown ECs.

(A) Extracellular acidification rate (ECAR) of HUVECs with si-control/scrambled RNA (siC) versus siPKM2 in the absence and presence of oligomycin (Oligo) demonstrating basal and maximal glycolytic rate, respectively (n = 8). (B) Relative abundance of glycolysis intermediates in HUVECs with siC versus siPKM2 were quantified by mass spectrometry after 24 hours of incubation (n = 3). (C) Pyruvate kinase activity of HUVECs with siC versus siPKM2 (n = 6). (D) PDH activity estimated by incorporation of [U-¹³C] glucose–derived carbons into M+2 citrate, αKG, and aspartate in HUVECs with siC versus siPKM2 (n = 3). (E) Pyruvate carboxylase (PC) activity estimated by incorporation of [U-¹³C] glucose–derived carbons into M+5 citrate (n = 3). (F) Relative abundance of TCA cycle intermediates in HUVECs with siC versus siPKM2 were quantified by mass spectrometry after 24 hours of incubation (n = 3). (G) Oxygen consumption rate (OCR) of HUVECs with siC versus siPKM2 was measured by Seahorse (n = 8). All data are mean ± SD. *P < 0.05, **P < 0.01, by 2-tailed Student’s t test.