Fuel the Failing Heart: glucose or fatty acids? Rong Tian, MD, PhD Mitochondria and Metabolism Center University of Washington, Seattle

Fuel the Failing Heart: glucose or fatty acids? Rong Tian, MD, PhD Mitochondria and Metabolism Center University of Washington, Seattle

Metabolic Remodeling: Fatty Acids Carbohydrates PCr/ATP

Glucose vs. fatty acids: Glucose: O2 efficient substrate, 11% saving in P:O C inefficient, 2/3 carbon enters TCA availability to the cardiac myocyte is subjected to insulin regulation Fatty acids: O2 inefficient substrate, requires 11% or more O2 than glucose high availability and C efficient, every carbon is oxidized FAO is dependent on mitochondrial function reactive lipid species Fatty Acids Carbohydrates PCr/ATP

Shifting Substrate Preference to Glucose by overexpressing GLUT1 1 % Oxidation 8 6 carb 4 2 fat WT TG FS% TG

Overexpressing GLUT1 delays the transition to failure and Improves Long-term Survival Post Ascending Aortic Constriction WT WT-AAC Animal Survival GLUT1-TG TG-AAC 1 8 6 4 2 WT-Sham WT-Band TG-Sham TG-Band 3 13 23 33 43 53 63 Days

Glucose is not toxic. A greater than endogenous capacity for glucose utilization is needed to compensate for impaired FAO in the adult heart. PPARα -/- mice whole body knockout x GLUT1 TG mice cardiac specific PPARα -/- GLUT1 TG

Contributions of glucose vs. fatty acids to the oxidative metabolism Baseline High workload

. n i m / g H m 3 m 1 Rate Pressure Product (1 3 mmhg/min) 9 8 7 6 5 4 3 2 1 RPP high workload 25 min. glucose mixed substrates +/+ WT WT -/- PPARα WT -/- -/- TG +/+ GLUT1 TG PPARα -/- GLUT1

[ATP] [ATP] (mm) M m 12 1 8 6 4 +/+ WT WT -/- WT -/- TG +/+ GLUT1 TG PPARα -/- PPARα -/- GLUT1 2 glucose high workload 25 min. mixed substrates

Normalized FAO? Maladaptive: Limited capacity for ATP synthesis use of glucose and use of fatty acids Further facilitates glucose utilization (GLUT1-TG) Adaptive: O 2 demand

Strategies: Enhance FAO via the PPARα mechanisms Cardiac PPARα-TG: cardiomyopathy Pharmacological activation: worse or no effects on cardiac function in hypertrophied heart High fat diet Delays the development of heart failure in certain models while worsens the outcome in others FA uptake >> FAO Mitochondrial FAO Manipulate long-chain fatty acid entry

Targeting Acetyl-CoA Carboxylase (ACC2) to Specifically Increase FAO Lipid synthesis MCD Acetyl CoA Fatty Acids ACS Malonyl CoA Malonyl CoA Acyl CoA CPT1 ACC1 ACC2 β-oxidation TCA Mitochondrion

Cardiac-specific deletion of ACC2 decreases Malonyl-CoA level ACC2 C57 f/wt f/f -/+ -/- Fold Change (from Control) 2. 1.5 1..5 ACC1 mrna. ACC2H -/- ACC2H-/- Heart Gastroc Liver nmol/g dry weight 2.5 2. 1.5 1..5. Malonyl CoA ACC2H -/-

Effects of ACC2 Deletion on Cardiac Metabolism % Oxidation TAG Content Glycogen Content Relative Contribution to Acetyl-CoA (%) 1 Glucose Fatty Acids Other 5 ACC2H-/- TAG (ug/mg) 6 4 2 ACC2H -/- Glucose (µmol/g) 15 1 5 ACC2H -/- MVO 2 MVO 2 /RPP µmol of O 2 /min/g ww ACC2H -/- 1 ACC2H-/- 8 6 4 2 Glucose-Pyruvate Mixed Substrate nmol/g protein Acylcarnitines 8 6 ACC2H -/- 4 2 C3 C4 C5 C8 C14 C16 nmol/mmhgx1 3 /g w.w 3 Glc+pyr mixed substrate 2 1 ACC2H -/- ACC2H -/- ACC2H -/- Fold Change (Relative to Control) 2. 1.5 1..5. Gene Expression glut1 glut4 mcd pdk4 cd36 ppara pparg cpt1b mcad ucp3 pgc1a pgc1b erra tfam Glucose Metabolism Lipid Metabolism Mitochondrial Biogenesis

High Workload Challenge in Isolated Perfused Heart PCr (mm) ATP (mm) 25 2 15 1 5 15 1 5 Phosphocreatine Baseline High Workload ATP ACC2H -/- ACC2H-/- HR (bpm) LVDevP (mmhg) 25 2 15 1 5 5 4 3 2 Cardiac Function High Workload BL 5 1 15 2 Heart Rate ACC2H-/- ACC2H-/- Pi (mm) 1 8 6 4 2 Baseline High Workload Inorganic Phosphate + Baseline High Workload ACC2H-/- EDP (mmhg) 1 25 2 15 1 5 High Workload BL 5 1 15 2 Diastolic Function High Workload BL 5 1 15 2 ACC2H -/-

Aging: Fatty acid metabolism is maintained with normal function and morphology up to 12 months of age Wall Thickness Contribution to Acetyl-CoA (%) 1 8 6 4 2 Substrate Utilization 2mos 12mos 2mos 12mos Fatty Acids Glucose ACC2H -/- LVPW;d (mm) Fractional Shortening (%) 2. 1.5 1..5. 8 6 4 2 2 months 12 months In-vivo Function 2 months 12 months ACC2H -/- ACC2H -/-

Pressure Overload: TAC Function % Contribution to Acetyl-CoA 1 5 Sham TAC Sham TAC ACC2H-/- Fatty Acids Glucose Other FS (%) 8 6 4 2 BL 4wk 8wk Sham TAC ACC2H -/- -Sham ACC2H -/- -TAC 13 C3-Alanine/ 13 C1-Glucose (AU).4.3.2.1. Alanine Sham TAC Sham TAC ACC2H-/- Sham TAC Sham TAC ACC2H-/- Anaplerosis/Citrate Synthase.15.1.5. Anaplerosis Sham TAC Sham TAC ACC2H-/- RPP (mmhgbpm1 3 ) 6 4 2 13 C-C3Lactate/ 13 C-C1Glucose (AU) 1..8.6.4.2. Lactate Sham TAC Sham TAC ACC2H-/- PCr/ATP 2. 1.5 1..5. PCr/ATP Sham TAC Sham TAC ACC2H-/- Fatty Acids PCr/ATP Carbohydrates

Reduced Hypertrophy and Fibrosis in ACC2H-/- 4 weeks Post-TAC Fold Change (from Control) 15 1 5 BNP HW:TL (mg/mm) 1 5 HW/TL Myocyte Area % Fibrosis Cross Sectional Area ( µm 2 ) 1 8 6 4 2 % Fibrosis 5 4 3 2 1 Sham TAC Sham TAC Sham TAC Sham TAC Sham TAC Sham TAC ACC2H-/- ACC2H-/- ACC2H-/- Sham TAC Sham TAC ACC2H-/- Sham -/- Sham Sham -/- Sham TAC -/- TAC TAC -/- TAC

Optimal energy metabolism Capacity: to meet the high energy demand Balance: uptake = utilization Flexibility: able to utilize what is available No one-size-fit-all substrate for the heart

Acknowledgement Ivan Luptak Jie Yan Stephen Kolwicz Jr. Lorena Garcia-Menendez Miranda Nabben Mei Shen Jessica D Agostino Francesco Aiello Yanqiu Xing Liqun Zou Bo Løfgren Biao Lei Georgios Karamanlidis Danos Christodoulou Maengjo Kim Queena Yu Yu-Ying Yang Sung Won Choi Rick M. Mortensen University of Michigan Dan Kelly Washington University, St. Louis Gary Lopaschuk University of Alberta Ronglih Liao Joanne Ingwall Jim Balschi Luigino Nascimben Jun Yoshioka, Richard Lee Brigham and Women s Hospital David Olson Beth Israel Deaconess Med Center Robert Synovec University of Washington