FIGURE 7.

CPT1mt expression and OA reach similar final effects via different mechanisms. Control, the SFA palmitate induces apoptosis in skeletal muscle cells by promoting intracellular TG, DAG, and ceramide accumulation. CPT1mt, CPT1mt expression reduces palmitate-induced apoptosis by increasing mitochondrial oxidation of palmitate and decreasing the production of TG, DAG, and ceramides. OA, preincubation with oleate prevents palmitate-induced apoptosis by promoting mitochondrial LCFA oxidation, secondary to increased CPT1mt expression and phospho-ACC/ACC ratio, and by channeling palmitate toward TG as a result of an enhanced DGAT2 expression. These two mechanisms reduce the availability of palmitate for incorporation into DAG and de novo ceramide synthesis. In conclusion, OA induces palmitate oxidation and storage into TG, whereas CPT1mt expression increases mitochondrial oxidation of palmitate.