FIG. 8.

Schematic representation of the role of fatty acid import into the mitochondria in the regulation of mitochondrial steroid production. The import of fatty acids into the mitochondria under wild-type conditions has been proposed to occur through VDAC and CPT1a, whereas cholesterol has been proposed to be imported via VDAC and TSPO. Upon inhibition of CPT1a via etomoxir, a decrease in fatty acid import is observed with an increase in imported cholesterol, which can be observed via an increased steroid production. Increasing fatty acid import through the use of metformin results in a decrease in the amount of cholesterol imported, which is determined via a decrease in steroid production.