Restoring mitochondrial function in the treatment of children born with congenital heart defects Steve Black, PhD Co-Director, Cardiovascular Discovery Institute & Mitochondrial Bioenergetics Core Chief, Pulmonary Vascular Disease Program Vascular Biology Center Georgia Regents University

R. Furchgott L. Ignarro F. Murad The cells we study

Developed by Reddy et al in Jeffery Fineman’s lab at UCSF Vascular graft (shunt) is placed between aorta and pulmonary artery in fetal lamb Shunt in place during fetal-newborn transition Model of early alterations that happen in children in with CHD Ovine Model of a Congenital Heart Defect with Increased Pulmonary Blood Flow Copyright ©1995 American Heart Association Circulation 1995;92:

4- Week -Old Shunt and Twin Control Lamb

There is a Progressive Loss of Endothelial Function in Shunt Lambs Am J Physiol Lung Cell Mol Physiol Nov;295(5):L NO generation

Mitochondria The organelle that releases energy in the cell. The powerhouse of the cell Mitochondria produce ATP using energy stored in food molecules Attenuation of mitochondrial function now being investigated in CV disease

Evidence of Mitochondrial Dysfunction in Shunt lambs Am J Physiol Lung Cell Mol Physiol 294: L46-L LactatePyruvateLactate: Pyruvate (µmols/gww)(µmols/gww) Ratio Control : 1 Shunt * * : 1* Data is mean + SE; N=5; *P<0.05 vs Control. gww= gram wet weight.

“Carnitine Shuttle” Endothelial cells burn fatty acids rather than glucose for 70% of their energy ATP

Can Determine Carnitine levels by HPLC Free Carnitines ( LC + ALC) Total Carnitines ACYL Carnitines GOOD BAD

Our Results: Total CarnitinesFree CarnitineL-carnitineAcylcarnitine (nmol/gww)(nmol/gww)(nmol/gww) (% total) Control % Shunt * * %* Data is mean + SE; N=5; *P<0.05 vs Control. gww= gram wet weight. Earlier Report : A case report with pulmonary hypertension Carnitine Palmitoyltransferase II Deficiency: A Clinical, Biochemical, and Molecular Review : Ellen Sigauke, Dinesh Rakheja, Kimberly Kitson and Michael J. Bennett ACYL-Carnitines But what about kids with CHD? Am J Physiol Lung Cell Mol Physiol 294: L46-L

Pre-operatively, patients with increased PBF have an increased acyl:free Carnitine Ratio *

Surgery increases free carnitine levels in children with VSD **

Studies from Ames lab have shown that supplementing aged rats with ALCAR improved mitochondrial energy metabolism and improves memory. Other studies have reported L-carnitine blunts oxidative stress related tissue damage in aging rats A large clinical trial has shown that L-carnitine reduces ventricular dilation in patients with acute anterior myocardial infarction. Smaller studies have indicated L-carnitine can improve endothelial function in patients with essential hypertension and diabetes. It has been used for >50yrs to treat various inborn errors of metabolism with no apparent side-effects Why Focus on L-carnitine Supplementation?

L-carnitine Supplementation Preserves Endothelial Function in Shunt lambs Sharma S et al Pediatr Res (1):39-47

Conclusions  Increased PBF induces mitochondrial dysfunction  The mitochondrial dysfunction is due, at least in part, to a disruption of the carnitine shuttle  L-carnitine supplementation preserves NO signaling & endothelial function in Shunt lambs  L-carnitine may have clinical utility in children with CHD and increased PBF  Obtained FDA approval & pilot clinical trial will start in Spring 2014

Acknowledgements All the tremendous efforts of my lab & administrative staff Jeffery Fineman Peter Oishi Angela Amburso Aida Field-Ridley UCSF UNC Cam Patterson Sohrab Fratz DHZ-Munich

Acknowledgements The Money!

Never surrender!!!