Inhibition of carnitine palymitoyltransferase1b induces cardiac hypertrophy and mortality in mice

• Published in: Diabetes, obesity & metabolism Vol. 16; no. 8; pp. 757 - 760
• Main Authors: Haynie, K. R., Vandanmagsar, B., Wicks, S. E., Zhang, J., Mynatt, R. L.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.2014; Wiley Subscription Services, Inc
• Subjects: Animals; cardiac hypertrophy; Cardiomegaly - chemically induced; Cardiomegaly - enzymology; Cardiomegaly - pathology; Cardiomegaly - physiopathology; Carnitine O-Palmitoyltransferase - antagonists & inhibitors; Carnitine O-Palmitoyltransferase - genetics; Carnitine O-Palmitoyltransferase - metabolism; Carnitine palmitoyltransferase; Chimera; Crosses, Genetic; Diabetes mellitus; Drugs, Investigational - adverse effects; Enzyme Inhibitors - adverse effects; fatty acid oxidation; Female; Glucose tolerance; Heart - drug effects; Heart - physiopathology; Hypertrophy; Hypoglycemic Agents - adverse effects; Insulin; Insulin Resistance; Isoforms; Male; Mice, Inbred C57BL; Mice, Knockout; Mortality; Muscle, Skeletal - drug effects; Muscle, Skeletal - enzymology; Muscle, Skeletal - physiopathology; Musculoskeletal system; Myocardium - enzymology; Myocardium - pathology; observational study; Organ Size - drug effects; Palmitoyltransferase; Protein Isoforms - antagonists & inhibitors; Protein Isoforms - genetics; Protein Isoforms - metabolism; Rodents; Seizures; Seizures - chemically induced; Seizures - enzymology; Seizures - pathology; Seizures - physiopathology; Skeletal muscle; Survival Analysis; carnitine palmitoyltransferase; fatty acid oxidation; cardiac hypertrophy; observational study
• ISSN: 1462-8902; 1463-1326; 1463-1326
• DOI: 10.1111/dom.12248

Recent reports suggest that short‐term pharmacological carnitine palmitoyltransferase 1 (Cpt1) inhibition improves skeletal muscle glucose tolerance and insulin sensitivity. Although this appears promising for the treatment of diabetes, these Cpt1 inhibitors are not specific to skeletal muscle and target multiple Cpt1 isoforms. To assess the effects of inhibiting the Cpt1b isoform we generated mice with a heart‐ and skeletal muscle‐specific deletion of the Cpt1b, Cpt1bHM−/−. These mice seem to develop normally with similar bodyweights as control mice. However, premature mortality was observed by 15 weeks of age in the Cpt1bHM−/− mice. The hearts of Cpt1bHM−/− mice were four times the size of controls. Cpt1bHM−/− mice were also subject to stress‐induced seizures that accompanied an increased risk for premature mortality. Our data suggests that prolonged Cpt1b inhibition poses severe cardiac risk and emphasizes that attempts to improve insulin sensitivity by targeting Cpt1 with current inhibitors is not viable.