A Non-invasive Method to Assess Hepatic Acetyl-CoA In Vivo Rachel J. Perry, Liang Peng, Gary W. Cline, Kitt Falk Petersen, Gerald I. Shulman  Cell Metabolism  Volume 25, Issue 3, Pages 749-756 (March 2017) DOI: 10.1016/j.cmet.2016.12.017 Copyright © 2017 Elsevier Inc. Terms and Conditions

Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 Synthetic Pathway for β-OHB Production from Acetyl-CoA and Related Hepatic Fluxes BDH1, β-OHB dehydrogenase; CS, citrate synthase; HMGCL, 3-hydroxymethyl-3-methylglutaryl-CoA lyase; HMGCS2, 3-hydroxy-3-methylglutaryl-CoA synthase 2; PC, pyruvate carboxylase; PDH, pyruvate dehydrogenase; PEP, phosphoenolpyruvate; PEPCK, phosphoenolpyruvate carboxykinase; PK, pyruvate kinase. Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 Hepatic Acetyl-CoA Degrades Rapidly after Excision Data are the mean ± SEM of n = 3 per time point. Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 This Study Employed Five Models with a Wide Range of Fasting Plasma Glucose Concentrations and Hepatic Glucose Production Rates (A) Hepatic glucose production (umol/min). (B) Liver acetyl-CoA content. (C) Plasma β-OHB concentration. (D) Whole-body β-OHB turnover. In all panels, data are the mean ± SEM of n = 8 (hyperinsulinemic-euglycemic clamp), n = 6 (HFD), or n =12 (control, HFD-STZ, T1D) rats per group. Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 β-OHB Turnover Strongly Correlates with Hepatic Acetyl-CoA Content (A) β-OHB turnover versus hepatic acetyl-CoA: individual data points. (B) β-OHB turnover versus hepatic acetyl-CoA: group means; data are the mean ± SEM of n = 8 (hyperinsulinemic-euglycemic clamp), n = 6 (HFD), or n = 12 (control, HFD-STZ, T1D) rats per group. (C) Plasma β-OHB versus hepatic acetyl-CoA. Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 5 Both β-OHB Turnover and Hepatic Acetyl-CoA Correlate with Hepatic Glucose Protection (A) HGP versus hepatic acetyl-CoA. (B) HGP versus whole-body β-OHB turnover. Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 6 Hepatic Glucose Production Is Dissociated from Hepatic Acetyl-CoA Content in Rats Infused with Glycerol (A–C) Plasma glycerol (A), glucose (B), and insulin (C). (D) Hepatic glucose production. (E and F) Plasma non-esterified fatty acid (E) and β-OHB concentrations (F). (G) Whole-body β-OHB turnover. (H) Hepatic acetyl-CoA content. Controls are duplicated from Figure 2. n = 12 controls and five glycerol-infused rats. Data are the mean ± SEM. ∗p <0.05, ∗∗p <0.01, ∗∗∗p <0.001, ∗∗∗∗p <0.0001 by a two-tailed paired (A)–(F) or unpaired (G) and (H) Student’s t test. Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 7 Hepatic Glucose Production Is Dissociated from Hepatic Acetyl-CoA Concentrations in the Comparison between the Recently Fed and the Starved States (A and B) Plasma glucose (A) and insulin (B) concentrations. (C) Whole-body glucose turnover. (D and E) Plasma β-OHB concentrations (D) and whole-body β-OHB turnover (E). (F) Hepatic acetyl-CoA. In all panels, data are the mean ± SEM of n = 5 per group. ∗p <0.05, ∗∗p <0.01, ∗∗∗∗p <0.0001 by the two-tailed unpaired Student’s t test. Cell Metabolism 2017 25, 749-756DOI: (10.1016/j.cmet.2016.12.017) Copyright © 2017 Elsevier Inc. Terms and Conditions