title: Rotenone Induces the Formation of 4-Hydroxynonenal Aggresomes. Role of ROS-Mediated Tubulin Hyperacetylation and Autophagic Flux Disruption.
abstract: Oxidative stress causes cellular damage by (i) altering protein stability, (ii) impairing organelle function, or (iii) triggering the formation of 4-HNE protein aggregates. The catabolic process known as autophagy is an antioxidant cellular response aimed to counteract these stressful conditions. Therefore, autophagy might act as a cytoprotective response by removing impaired organelles and aggregated proteins. In the present study, we sought to understand the role of autophagy in the clearance of 4-HNE protein aggregates in ARPE-19 cells under rotenone exposure. Rotenone induced an overproduction of reactive oxygen species (ROS), which led to an accumulation of 4-HNE inclusions, and an increase in the number of autophagosomes. The latter resulted from a disturbed autophagic flux rather than an activation of the autophagic synthesis pathway. In compliance with this, rotenone treatment induced an increase in LC3-II while upstream autophagy markers such as Beclin- 1, Vsp34 or Atg5-Atg12, were decreased. Rotenone reduced the autophagosome-to-lysosome fusion step by increasing tubulin acetylation levels through a ROS-mediated pathway. Proof of this is the finding that the free radical scavenger, N-acetylcysteine, restored autophagy flux and reduced rotenone-induced tubulin hyperacetylation. Indeed, this dysfunctional autophagic response exacerbates cell death triggered by rotenone, since 3-methyladenine, an autophagy inhibitor, reduced cell mortality, while rapamycin, an inductor of autophagy, caused opposite effects. In summary, we shed new light on the mechanisms involved in the autophagic responses disrupted by oxidative stress, which take place in neurodegenerative diseases such as Huntington or Parkinson diseases, and age-related macular degeneration.
authors.affiliation: Facultad de Medicina y Odontología, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Bonet-Ponce
authors.affiliation: Facultad de Medicina y Odontología, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.|Unidad de Neuropsicofarmacología Traslacional, Complejo Hospitalario Universitario de Albacete, Albacete, Spain.|Grupo de Neurofarmacología, Dpto. Ciencias Médicas. Facultad de Medicina de Albacete, IDINE, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Saez-Atienzar
authors.affiliation: Grupo de Neurofarmacología, Dpto. Ciencias Médicas. Facultad de Medicina de Albacete, IDINE, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: da Casa
authors.affiliation: Facultad de Medicina y Odontología, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Sancho-Pelluz
authors.affiliation: Facultad de Medicina y Odontología, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Barcia
authors.affiliation: Facultad de Medicina y Odontología, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Martinez-Gil
authors.affiliation: Grupo de Neurofarmacología, Dpto. Ciencias Médicas. Facultad de Medicina de Albacete, IDINE, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Nava
authors.affiliation: Grupo de Neurofarmacología, Dpto. Ciencias Médicas. Facultad de Medicina de Albacete, IDINE, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Jordan
authors.affiliation: Facultad de Medicina y Odontología, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Romero
authors.affiliation: Unidad de Neuropsicofarmacología Traslacional, Complejo Hospitalario Universitario de Albacete, Albacete, Spain. mgalindoa@sescam.jccm.es.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Galindo
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000447:Aldehydes / Q000378:metabolism*; D000071182:Autophagosomes / Q000187:drug effects / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects*; D002460:Cell Line; D006801:Humans; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008561:Membrane Fusion / Q000187:drug effects; D008954:Models, Biological; D066329:Protein Aggregates / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012402:Rotenone / Q000494:pharmacology*; D014404:Tubulin / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D066329:Protein Aggregates; D017382:Reactive Oxygen Species; D014404:Tubulin; D012402:Rotenone; C027576:4-hydroxy-2-nonenal
keywords: Autophagy; Mitochondria; Reactive oxygen species; Tubulin