Fig 4.

Schematic representation of lipolytic mechanism. Under normal condition, triglycerides (TAGs), stored within the lipid droplets, are mobilized in response to energy demands. TAG hydrolysis consists of a series of interrelated reactions. The primary intracellular lipase is the adipose triglyceride lipase (ATGL), which is activated through the interaction with ABHD5. ATGL promotes the release of the first fatty acid (FA) from TAGs, producing diacylglycerols (DAGs). The second lipase is the hormone-sensitive lipase (HSL), which leads to DAGs conversion into monoacylglycerols (MAGs). The lipolytic cascade culminates with the monoglyceride lipase (MGL) activity, which induces third FA and glycerol release. FAs are then delivered to mitochondria to produce energy through β-oxidation. In CDS condition, ABHD5 mutations cause a decrease of ATGL function, determining a defect of lipolytic pathway and a decrease of mitochondrial energy production. Supplementation of MCT oil provides medium-chain fatty acids containing 6 to 12 carbon atoms, which diffuse into the cells and enter directly the mitochondria, where they supply fuel to produce energy.