title: Macrophage autophagy and oxidative stress: an ultrastructural and immunoelectron microscopical study.
abstract: The word autophagy broadly refers to the cellular catabolic processes that lead to the removal of damaged cytosolic proteins or cell organelles through lysosomes. Although autophagy is often observed during programmed cell death, it may also serve as a cell survival mechanism. Accumulation of reactive oxygen species within tissues and cells induces various defense mechanisms or programmed cell death. It has been shown that, besides inducing apoptosis, oxidative stress can also induce autophagy. To date, however, the regulation of autophagy in response to oxidative stress remains largely elusive and poorly understood. Therefore, the present study was designed to examine the ratio between oxidative stress and autophagy in macrophages after oxidant exposure (AAPH) and to investigate the ultrastructural localization of beclin-1, a protein essential for autophagy, under basal and stressful conditions. Our data provide evidence that oxidative stress induces autophagy in macrophages. We demonstrate, for the first time by immunoelectron microscopy, the subcellular localization of beclin-1 in autophagic cells.
authors.affiliation: Department of Ecology, Faculty of Mathematical, Physical and Natural Sciences (SMFN), University of Calabria, Cosenza, Italy. idaperrotta@yahoo.it
authors.forename: Ida
authors.initials: I
authors.lastname: Perrotta
authors.forename: Valentina
authors.initials: V
authors.lastname: Carito
authors.forename: Emilio
authors.initials: E
authors.lastname: Russo
authors.forename: Sandro
authors.initials: S
authors.lastname: Tripepi
authors.forename: Saveria
authors.initials: S
authors.lastname: Aquila
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Donato
mesh_terms: D000328:Adult; D000578:Amidines / Q000494:pharmacology; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001343:Autophagy; D000071186:Beclin-1; D006046:Gold / Q000737:chemistry; D006801:Humans; D008264:Macrophages / Q000378:metabolism / Q000648:ultrastructure*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000578:Amidines; D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D008565:Membrane Proteins; D016877:Oxidants; D017382:Reactive Oxygen Species; C046728:2,2'-azobis(2-amidinopropane); D006046:Gold