Macrophage Autophagy Plays a Protective Role in Advanced Atherosclerosis

Xianghai Liao, Judith C. Sluimer, Ying-Jan Wang, Manikandan Subramanian, Kristy Brown, J. Scott Pattison, Jeffrey Robbins, Jennifer Martinez, Ira Tabas*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

In advanced atherosclerosis, macrophage apoptosis coupled with defective phagocytic clearance of the apoptotic cells (efferocytosis) promotes plaque necrosis, which precipitates acute atherothrombotic cardiovascular events. Oxidative and endoplasmic reticulum (ER) stress in macrophages are important causes of advanced lesional macrophage apoptosis. We now show that proapoptotic oxidative/ER stress inducers trigger another stress reaction in macrophages, autophagy. Inhibition of autophagy by silencing ATG5 or other autophagy mediators enhances apoptosis and NADPH oxidase-mediated oxidative stress while at the same time rendering the apoptotic cells less well recognized by efferocytes. Most importantly, macrophage ATG5 deficiency in fat-fed Ldlr(-/-) mice increases apoptosis and oxidative stress in advanced lesional macrophages, promotes plaque necrosis, and worsens lesional efferocytosis. These findings reveal a protective process in oxidatively stressed macrophages?relevant to plaque necrosis, suggesting?a mechanism-based strategy to therapeutically suppress atherosclerosis progression and its clinical sequelae.
Original languageEnglish
Pages (from-to)545-553
JournalCell Metabolism
Volume15
Issue number4
DOIs
Publication statusPublished - 4 Apr 2012

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