Laboratory Study of Acyl-CoA Dehydrogenase

Mitochondrial fatty acid oxidation (FAO) plays a pivotal role in energy homeostasis of the heart, skeletal muscle, and liver during fasting, increased energy demand, and catabolic stress. Patients with long-chain FAO defects (LCFAODs) lack specific enzymes linked to mitochondrial β-oxidation, causing non-ketotic hypoglycemia, cardiomyopathy, arrhythmias, sudden death, and liver disease during fasting or catabolic states or recurrent attacks of rhabdomyolysis during stress or prolonged exercise. Management of LCFAODs by current measures remains nonspecific, limited to avoiding prolonged fasting by providing diets low in fat but high in carbohydrates and proteins, and doses of medium-chain triglyceride (MCT) oil or triheptanoin (C7).

Medical Genetics researchers at Children’s Hospital of Pittsburgh of UPMC have previously reported that the mitochondrial trifunctional protein (TFP) lies at the interface between FAO and the mitochondrial electron transfer chain (ETC). Through its physical interaction with complex I in mitochondria supercomplexes, it forms a potential metabolic channel for reducing equivalents to pass from FAO to the ETC. Using a series of functional assays developed here, investigators are studying the balance of mitochondrial energy metabolism in different types of cells deficient in TFP (HEK293, mice deficient in TFP cells, and human cell lines). Cellular models of FAO defects provide an ideal opportunity to examine pathophysiology and test the metabolic effects of potential therapeutic agents. These experiments could improve our understanding of the role TFP plays at the center of an energy metabolon, allowing development of strategies to stabilize deficient pathways, and assess new therapies.

Principal Investigator

Areeg El-Gharbawy, MD