TFEB activation in macrophages attenuates postmyocardial infarction ventricular dysfunction independently of ATG5-mediated autophagy

Ali Javaheri, Geetika Bajpai, Antonino Picataggi, Smrithi Mani, Layla Foroughi, Hosannah Evie, Attila Kovacs, Carla J. Weinheimer, Krzystztof Hyrc, Qingli Xiao, Andrea Ballabio, Jin-Moo Lee, Scot J. Matkovich, Babak Razani, Joel D. Schilling, Kory J. Lavine, and Abhinav Diwan. JCI Insight, Volume 4, Issue 21, 1 November 2019, Article number e127312 Read More

Abstract

Lysosomes are at the epicenter of cellular processes critical for inflammasome activation in macrophages. Inflammasome activation and IL-1β secretion are implicated in myocardial infarction (MI) and resultant heart failure; however, little is known about how macrophage lysosomes regulate these processes. In mice subjected to cardiac ischemia/reperfusion (IR) injury and humans with ischemic cardiomyopathy, we observed evidence of lysosomal impairment in macrophages. Inducible macrophage-specific overexpression of transcription factor EB (TFEB), a master regulator of lysosome biogenesis (M-TFEB), attenuated postinfarction remodeling, decreased abundance of proinflammatory macrophages, and reduced levels of myocardial IL-1β compared with controls. Surprisingly, neither inflammasome suppression nor M-TFEB mediated attenuation of postinfarction myocardial dysfunction required intact ATG5-dependent macroautophagy (hereafter termed “autophagy”). RNA-seq of flow-sorted macrophages postinfarction revealed that M-TFEB upregulated key targets involved in lysosomal lipid metabolism. Specifically, inhibition of the TFEB target, lysosomal acid lipase, in vivo abrogated the beneficial effect of M-TFEB on postinfarction ventricular function. Thus, TFEB reprograms macrophage lysosomal lipid metabolism to attenuate remodeling after IR, suggesting an alternative paradigm whereby lysosome function affects inflammation. © 2019 American Society for Clinical Investigation. All rights reserved.

Full Text

.

Posted on January 21, 2020
Posted in: HPAN, Lysosome, Neurodegeneration, Neurogenetics & Transcriptomics, Publications Authors: ,