title: cAMP increases mitochondrial cholesterol transport through the induction of arachidonic acid release inside this organelle in Leydig cells.
abstract: We have investigated the direct effect of arachidonic acid on cholesterol transport in intact cells or isolated mitochondria from steroidogenic cells and the effect of cyclic-AMP on the specific release of this fatty acid inside the mitochondria. We show for the first time that cyclic-AMP can regulate the release of arachidonic acid in a specialized compartment of MA-10 Leydig cells, e.g. the mitochondria, and that the fatty acid induces cholesterol transport through a mechanism different from the classical pathway. Arachidonic acid and arachidonoyl-CoA can stimulate cholesterol transport in isolated mitochondria from nonstimulated cells. The effect of arachidonoyl-CoA is inhibited by the reduction in the expression or in the activity of a mitochondrial thioesterase that uses arachidonoyl-CoA as a substrate to release arachidonic acid. cAMP-induced arachidonic acid accumulation into the mitochondria is also reduced when the mitochondrial thioesterase activity or expression is blocked. This new feature in the regulation of cholesterol transport by arachidonic acid and the release of arachidonic acid in specialized compartment of the cells could offer novel means for understanding the regulation of steroid synthesis but also would be important in other situations such as neuropathological disorders or oncology disorders, where cholesterol transport plays an important role.
authors.affiliation: Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina.
authors.forename: Ana Fernanda
authors.initials: AF
authors.lastname: Castillo
authors.forename: Fabiana
authors.initials: F
authors.lastname: Cornejo Maciel
authors.forename: Rocío
authors.initials: R
authors.lastname: Castilla
authors.forename: Alejandra
authors.initials: A
authors.lastname: Duarte
authors.forename: Paula
authors.initials: P
authors.lastname: Maloberti
authors.forename: Cristina
authors.initials: C
authors.lastname: Paz
authors.forename: Ernesto J
authors.initials: EJ
authors.lastname: Podestá
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D001692:Biological Transport; D002784:Cholesterol / Q000378:metabolism*; D000242:Cyclic AMP / Q000502:physiology*; D005227:Fatty Acids / Q000502:physiology; D007985:Leydig Cells / Q000378:metabolism*; D008297:Male; D051379:Mice; D008928:Mitochondria / Q000378:metabolism* / Q000502:physiology; D015388:Organelles / Q000378:metabolism; D011374:Progesterone / Q000096:biosynthesis; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D005227:Fatty Acids; D016718:Arachidonic Acid; D011374:Progesterone; D002784:Cholesterol; D000242:Cyclic AMP