title: Apoptotic cells subjected to cold/warming exposure disorganize apoptotic microtubule network and undergo secondary necrosis.
abstract: Apoptotic microtubule network (AMN) is organized during apoptosis, forming a cortical structure beneath the plasma membrane which plays a critical role in preserving cell morphology and plasma membrane integrity. The aim of this study was to examine the effect of cold/warming exposure on apoptotic microtubules and plasma membrane integrity during the execution phase of apoptosis. We demonstrated in camptothecin-induced apoptotic H460 cells that cold/warming exposure disorganized apoptotic microtubules and allowed the access of active caspases to the cellular cortex and the cleavage of essential proteins in the preservation of plasma membrane permeability. Cleavage of cellular cortex and plasma membrane proteins, such as α-spectrin, paxilin, focal adhesion kinase and calcium ATPase pump (PMCA-4) involved in cell calcium extrusion resulted in increased plasma permeability and calcium overload leading apoptotic cells to secondary necrosis. The essential role of caspase-mediated cleavage in this process was demonstrated because the addition of the pan-caspase inhibitor z-VAD during cold/warming exposure that induces AMN depolymerization avoided the cleavage of cortical and plasma membrane proteins and prevented apoptotic cells to undergo secondary necrosis. Likewise, apoptotic microtubules stabilization by taxol during cold/warming exposure also prevented cellular cortex and plasma membrane protein cleavage and secondary necrosis. Furthermore, microtubules stabilization or caspase inhibition during cold/warming exposure was also critical for proper phosphatidylserine externalization and apoptotic cell clearance by macrophages. These results indicate that cold/warming exposure of apoptotic cells induces secondary necrosis which can be prevented by both, microtubule stabilization or caspase inhibition.
authors.affiliation: Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Carretera de Utrera Km 1, 41013, Seville, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Oropesa-Ávila
authors.forename: Alejandro
authors.initials: A
authors.lastname: Fernández-Vega
authors.forename: Mario
authors.initials: M
authors.lastname: de la Mata
authors.forename: Juan
authors.initials: J
authors.lastname: Garrido-Maraver
authors.forename: David
authors.initials: D
authors.lastname: Cotán
authors.forename: Marina Villanueva
authors.initials: MV
authors.lastname: Paz
authors.forename: Ana Delgado
authors.initials: AD
authors.lastname: Pavón
authors.forename: Mario D
authors.initials: MD
authors.lastname: Cordero
authors.forename: Elizabet
authors.initials: E
authors.lastname: Alcocer-Gómez
authors.forename: Isabel
authors.initials: I
authors.lastname: de Lavera
authors.forename: Rafael
authors.initials: R
authors.lastname: Lema
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Zaderenko
authors.forename: José A
authors.initials: JA
authors.lastname: Sánchez-Alcázar
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D002166:Camptothecin / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D003080:Cold Temperature; D006358:Hot Temperature; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000648:ultrastructure*; D009336:Necrosis; D009842:Oligopeptides / Q000494:pharmacology; D017239:Paclitaxel / Q000494:pharmacology; D010718:Phosphatidylserines / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D008565:Membrane Proteins; D009842:Oligopeptides; D010718:Phosphatidylserines; C517629:benzyloxycarbonyl-valyl-alanyl-aspartic acid; D020169:Caspases; D017239:Paclitaxel; D002118:Calcium; D002166:Camptothecin