Fig. 3
Decreased glucose carbon flux and the pentose phosphate pathway. a Schematic representing incorporation of 13C derived from glucose into metabolites of glycolysis and the Krebs cycle. White and black circles are 12C and 13C, respectively. b Decreased labeled but similar total palmitate pools in FASN∆/∆-PyMT MEFs compared with FASNlox/lox-PyMT MEFs. 13C-NMR spectrum showing the central peak (singlet) at 14.17 p.p.m. characteristic of the terminal methyl group (–CH3 or omega-1 carbon) of a fatty acid, and lateral peaks (doublet signal) corresponding to the penultimate –CH2- (or omega-2 carbon) due to 13C–13C coupling. c Isotopolog abundance of glucose-6-P (determined by LC/MS) and lactate (determined by RMN). d Glut1 and Glut4 glucose transporter mRNA levels determined by RT-qPCR, relativized to FASNlox/lox-PyMT values. The experiment was repeated three times. e Total abundance of citrate/isocitrate and % labeling of citrate, aconitate, fumarate, and malate isotopologs in MEFs labeled with [U-13C]glucose (determined by LC/MS) (n = 5 biological replicates), and f % labeling of –CH2 succinate isotopomer (determined by RMN) (n = 5 biological replicates). g Isotopolog abundance of ADP ribose and AMP determined by LC/MS in FASNlox/lox-PyMT and FASN∆/∆-PyMT MEFs (n = 5 biological replicates). Presented data are the mean values ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001; n.s., not statistically significant; Student’s t test
