Original Contribution Lipid oxidation and autophagy in yeast Ingrid Kiššová a,b , Maïka Deffieu a , Victor Samokhvalov a,1 , Gisèle Velours a , Jean-Jacques Bessoule c , Stéphen Manon a , Nadine Camougrand a, ⁎ a UMR5095 CNRS, Université de Bordeaux 2, 1 Rue Camille Saint-Saëns, F-33077 Bordeaux Cedex, France b Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynska Dolina CH-1, 84215 Bratislava, Slovak Republic c UMR5200 CNRS, Université de Bordeaux 2, 176 Rue Léo Saignat, F-33076 Bordeaux Cedex, France Received 16 May 2006; revised 2 August 2006; accepted 11 August 2006 Available online 16 August 2006 Abstract Autophagy, a process involved in the degradation and the recycling of long-lived proteins and organelles to survive nitrogen starvation, is generally non-selective. However, recent data suggest that selective forms of autophagy exist, that are able to specifically target several organelles, including mitochondria. Conversely, mitochondrial alterations could trigger autophagy. Such a selective form of autophagy might be involved in the elimination of damaged mitochondria. We reported previously that, mitochondria were early targets of rapamycin-induced autophagy. Here we report that rapamycin-induced autophagy is accompanied by the early production of reactive oxygen species and by the early oxidation of mitochondrial lipid. Inhibition of these oxidative effects by resveratrol largely impaired autophagy of both cytosolic proteins and mitochondria, and delayed subsequent cell death. These results support a role of mitochondrial oxidation events in the activation of autophagy. © 2006 Elsevier Inc. All rights reserved. Keywords: Autophagy; Mitochondria; Resveratrol; Yeast Autophagy is a general intracellular degradation process playing a crucial role in survival to nitrogen starvation in yeast [1,2 for reviews], plants [3, for review], cultured animal cells [4, for review] and in the whole animals [5,6]. It has been particularly well characterized in the yeast Saccharomyces cerevisiae, from genetic screens based on the sensitivity to nitrogen starvation [1,2,7 for reviews]. The main process of autophagy is known as macroautophagy. It involves the formation of double-membrane vesicles, named autophago- somes that engulf and deliver cytosolic material to the vacuoles. A similar process occurs in mammalian cells, where autophagosomes fuse with lysosomes, then forming autolysosomes [4]. Although macroautophagy is generally a non-selective process (i.e. engulfed material can virtually be anything and is randomly sequestered), selective processes have been described for the degradation of peroxisomes (pexophagy) in the methylotrophic yeasts Pichia pastoris [8], Hansenula polymorpha [9] and in Saccharomyces cerevisiae [10, for review] and in mammals [11, for review]. Besides macroautophagy, another form of autophagy, called micro- autophagy, involves the direct engulfment of portions of the cytoplasm by invaginations of the vacuole, by a molecular mechanism that remains unclear. Like macroautophagy, microautophagy is generally non-selective. However, a particular form of microautophagy, piecemeal microautophagy of the nucleus (PMN), has been described in S.cerevisiae [12]. Also, the existence of a selective form of microautophagy of the peroxisomes (micropexophagy) has been reported in yeasts [13]. Free Radical Biology & Medicine 41 (2006) 1655 – 1661 www.elsevier.com/locate/freeradbiomed Abbreviations: ALP, alkaline phosphatase; CL, cardiolipin (diphosphatidyl- glycerol); ctrl, control; C 16:0 , palmitic acid; C 16:1 , palmitoleic acid; C 18:0 , stearic acid; C 18:1 , oleic acid; C 18:2 , linoleic acid; mtGFP, mitochondria-targeted green fluorescent protein; NAC, N- acetylcysteine; PA, phosphatidic acid; PC, phosphatidylcholine; PE, phosphatidylethanolamine; PG, phosphatidylglycerol; PI, phosphatidylinositol; PMN, piecemeal microautophagy of the nucleus; PS, phosphatidylserine; rapa, rapamycin; resv, resveratrol; ROS, reactive oxygen species; TBARS, thiobarbituric-reactive species; YNB, yeast nitrogen base medium; YPD, yeast extract peptone dextrose medium. ⁎ Corresponding author. E-mail address: n.camougrand@ibgc.u-bordeaux2.fr (N. Camougrand). 1 Present address: The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8. 0891-5849/$ - see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.freeradbiomed.2006.08.012