Autophagic Punctum

Autophagy is impaired in cardiac ischemia-reperfusion injury

Volume 8, Issue 9   September 2012
Pages 1394 - 1396
http://dx.doi.org/10.4161/auto.21036
Keywords: BECN1, LAMP2, autophagic flux, cell death, ischemia-reperfusion, reactive oxygen species
Authors: Xiucui Ma, Haiyan Liu, Sarah R. Foyil, Rebecca J. Godar, Carla J. Weinheimer and Abhinav Diwan

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Abstract:
Accumulating evidence attests to a prosurvival role for autophagy under stress, by facilitating removal of damaged proteins and organelles and recycling basic building blocks, which can be utilized for energy generation and targeted macromolecular synthesis to shore up cellular defenses. These observations are difficult to reconcile with the dichotomous prosurvival and death-inducing roles ascribed to macroautophagy in cardiac ischemia and reperfusion injury, respectively. A careful reexamination of ‘flux’ through the macroautophagy pathway reveals that autophagosome clearance is markedly impaired with reperfusion (reoxygenation) in cardiomyocytes following an ischemic (hypoxic) insult, resulting from reactive oxygen species (ROS)-mediated decline in LAMP2 and increase in BECN1 abundance. This results in impaired autophagy that is ‘ineffective’ in protecting against cell death with ischemia-reperfusion injury. Restoration of autophagosome clearance and by inference, ‘adequate’ autophagy, attenuates reoxygenation-induced cell death.

Autophagic Punctum to:
X Ma, H Liu, SR Foyil, RJ Godar, CJ Weinheimer, JA Hill, et al. Impaired Autophagosome Clearance Contributes to Cardiomyocyte Death in Ischemia-Reperfusion Injury. Circulation 2012; 125: 3170-81
PMID: 22592897 DOI: 10.1161/CIRCULATIONAHA.111.041814

Received: June 5, 2012; Accepted: June 6, 2012; Published Online: August 14, 2012

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