Carnitine O-palmitoyltransferase 1B (CPT1B) (CPT1B)

Carnitine O-palmitoyltransferase 1B (CPT1B) is the muscle-specific isoform of the rate-limiting enzyme responsible for the transport of long-chain fatty acids into the mitochondria for beta-oxidation [1, 10]. Predominantly expressed in skeletal muscle and heart tissue, CPT1B plays a critical role in maintaining cellular energy homeostasis by regulating the balance between fatty acid and glucose metabolism [1, 2, 7]. In metabolic diseases such as obesity and type 2 diabetes, CPT1B is a therapeutic target because its inhibition can shift the energy substrate preference from fatty acids to glucose, thereby improving insulin sensitivity and glucose tolerance [1, 2, 4]. In the context of cardiovascular disease, modulating CPT1B activity is explored to enhance cardiac efficiency in heart failure, although chronic or excessive inhibition may lead to adverse effects like cardiac hypertrophy and lipotoxicity [3, 13, 15]. Pharmacological agents such as etomoxir and oxfenicine have been developed to target this enzyme, but their clinical application is often limited by safety concerns and a lack of isoform selectivity [1, 12]. Research also suggests potential roles for CPT1B in cancer cell metabolism and neurodegenerative conditions, further expanding its relevance as a clinical target [1, 8].

Other names

CPT1-MCPTI-MM-CPT1Carnitine palmitoyltransferase I muscle isoform

Inhibition of CPT1B activity to decrease the transport of long-chain fatty acids into the mitochondria, thereby reducing fatty acid oxidation and promoting a metabolic shift toward glucose oxidation [1, 4].