Tumor necrosis factor receptor-associated factor 2 mediates mitochondrial autophagy.

BACKGROUND Tumor necrosis factor (TNF) signaling protects against ischemia/reperfusion-induced cardiomyocyte death, in vitro, ex vivo, and in vivo. TNF-receptor-associated factor 2 (TRAF2), an E3 ubiquitin ligase, coordinates cytoprotective signaling downstream of both TNF receptors, via unclear mechanisms. Noting that TRAF2 is recruited to mitochondria, and that autophagic removal of ubiquitin-tagged damaged mitochondria is cytoprotective, we tested the hypothesis that TRAF2 mediates mitochondrial autophagy. METHODS AND RESULTS TRAF2 localizes to the mitochondria in neonatal rat cardiac myocytes, and TNF treatment transcriptionally upregulates TRAF2 abundance in the mitochondrial subfraction. TRAF2 colocalizes with ubiquitin, p62 adaptor protein, and mitochondria within LC3-bound autophagosomes; and exogenous TRAF2 enhances autophagic removal of mitochondria. TRAF2 knockdown with adenoviral shRNA transduction induces accumulation of depolarized mitochondria in resting neonatal rat cardiac myocytes, as well as in those treated with TNF or uncoupling agent carbonyl cyanide m-chlorophenyl hydrazone, suggesting an essential role for TRAF2 in homeostatic and stress-induced mitochondrial autophagy. TRAF2 also colocalizes and interacts with PARKIN, a previously described E3 ubiquitin ligase and mitophagy effector, on depolarized mitochondria in neonatal rat cardiac myocytes. Exogenous expression of TRAF2, but not its E3 ligase-deficient mutants, is sufficient to partially restore mitophagy in the setting of PARKIN knockdown, suggesting redundancy in their ubiquitin ligase roles. TRAF2 abundance increases in the mitochondrial subfraction of ischemia/reperfusion-modeled hearts; and exogenous TRAF2, but not its E3 ligase-deficient mutants, reduces depolarized mitochondria and rescues cell death in neonatal rat cardiac myocytes subjected to hypoxia/reoxygenation. CONCLUSIONS Taken together, these data indicate an essential role for TRAF2 in concert with PARKIN as a mitophagy effector, which contributes to TRAF2-induced cytoprotective signaling.

[1]  Yingming Zhao,et al.  Site-specific ubiquitination is required for relieving the transcription factor Miz1-mediated suppression on TNF-α–induced JNK activation and inflammation , 2011, Proceedings of the National Academy of Sciences.

[2]  F. Gao,et al.  The Cytoprotective Effects of Tumor Necrosis Factor Are Conveyed Through Tumor Necrosis Factor Receptor–Associated Factor 2 in the Heart , 2010, Circulation. Heart failure.

[3]  T. Mak,et al.  Crucial role for TNF receptor-associated factor 2 (TRAF2) in regulating NFκB2 signaling that contributes to autoimmunity , 2011, Proceedings of the National Academy of Sciences.

[4]  Cheng Luo,et al.  SPHINGOSINE-1-PHOSPHATE: A MISSING COFACTOR FOR THE E3 UBIQUITIN LIGASE TRAF2 , 2010, Nature.

[5]  Atsushi Tanaka,et al.  PINK1 Is Selectively Stabilized on Impaired Mitochondria to Activate Parkin , 2010, PLoS biology.

[6]  D. Kabelitz,et al.  Compartmentalization of TNF receptor 1 signaling: internalized TNF receptosomes as death signaling vesicles. , 2004, Immunity.

[7]  L. Opie,et al.  Pharmacological Preconditioning With Tumor Necrosis Factor-α Activates Signal Transducer and Activator of Transcription-3 at Reperfusion Without Involving Classic Prosurvival Kinases (Akt and Extracellular Signal–Regulated Kinase) , 2005, Circulation.

[8]  Sonya P Lad,et al.  Identification of MAVS splicing variants that interfere with RIGI/MAVS pathway signaling. , 2008, Molecular immunology.

[9]  D. Goeddel,et al.  Early lethality, functional NF-kappaB activation, and increased sensitivity to TNF-induced cell death in TRAF2-deficient mice. , 1997, Immunity.

[10]  Zhijian J. Chen,et al.  Role of the Clathrin Terminal Domain in Regulating Coated Pit Dynamics Revealed by Small Molecule Inhibition , 2011, Cell.

[11]  S. Akira,et al.  Mitochondrial DNA That Escapes from Autophagy Causes Inflammation and Heart Failure , 2012, Nature.

[12]  Sarah L. Brown,et al.  A key role for autophagy and the autophagy gene Atg16l1 in mouse and human intestinal Paneth cells , 2008, Nature.

[13]  R. Youle,et al.  Parkin is recruited selectively to impaired mitochondria and promotes their autophagy , 2008, The Journal of cell biology.

[14]  T. Ueland,et al.  The tumor necrosis factor superfamily in heart failure. , 2006, Future cardiology.

[15]  Z. Ronai,et al.  Ubiquitination and translocation of TRAF2 is required for activation of JNK but not of p38 or NF‐κB , 2004, The EMBO journal.

[16]  D. Mann,et al.  Left Ventricular Remodeling in Transgenic Mice With Cardiac Restricted Overexpression of Tumor Necrosis Factor , 2001, Circulation.

[17]  Joseph A. Hill,et al.  Impaired Autophagosome Clearance Contributes to Cardiomyocyte Death in Ischemia/Reperfusion Injury , 2012, Circulation.

[18]  A. Diwan,et al.  Enhancing lysosome biogenesis attenuates BNIP3-induced cardiomyocyte death , 2011, Autophagy.

[19]  C. Culmsee,et al.  Parkin Mediates Neuroprotection through Activation of IκB Kinase/Nuclear Factor-κB Signaling , 2007, The Journal of Neuroscience.

[20]  Xiaoxue Zhang,et al.  Parkin Protein Deficiency Exacerbates Cardiac Injury and Reduces Survival following Myocardial Infarction*♦ , 2012, The Journal of Biological Chemistry.

[21]  Youngil Lee,et al.  Cyclophilin D is required for mitochondrial removal by autophagy in cardiac cells , 2010, Autophagy.

[22]  P. Lambin,et al.  Autophagy is required during cycling hypoxia to lower production of reactive oxygen species. , 2009, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[23]  Chengqun Huang,et al.  LPS-induced autophagy is mediated by oxidative signaling in cardiomyocytes and is associated with cytoprotection. , 2009, American journal of physiology. Heart and circulatory physiology.

[24]  Xiangmei Zhou,et al.  A role for mitochondria in NLRP3 inflammasome activation , 2011, Nature.

[25]  D. Mann,et al.  Tumor Necrosis Factor- (cid:97) Confers Resistance to Hypoxic Injury in the Adult Mammalian Cardiac Myocyte , 2022 .

[26]  M. Duchen,et al.  Inhibiting mitochondrial permeability transition pore opening at reperfusion protects against ischaemia-reperfusion injury. , 2003, Cardiovascular research.

[27]  D. Mann,et al.  Desmin mediates TNF-α–induced aggregate formation and intercalated disk reorganization in heart failure , 2008, The Journal of cell biology.

[28]  Hong-Bing Shu,et al.  TRADD–TRAF2 and TRADD–FADD Interactions Define Two Distinct TNF Receptor 1 Signal Transduction Pathways , 1996, Cell.

[29]  G. Semenza,et al.  Mitochondrial Autophagy Is an HIF-1-dependent Adaptive Metabolic Response to Hypoxia* , 2008, Journal of Biological Chemistry.

[30]  C. Zechner,et al.  Transcriptional coactivators PGC-1alpha and PGC-lbeta control overlapping programs required for perinatal maturation of the heart. , 2008, Genes & development.

[31]  D. Jewell,et al.  NOD2 stimulation induces autophagy in dendritic cells influencing bacterial handling and antigen presentation , 2010, Nature Medicine.

[32]  D. Mann.  The emerging role of innate immunity in the heart and vascular system: for whom the cell tolls. , 2011, Circulation research.

[33]  R. Takahashi,et al.  PINK1 and Parkin complementarily protect dopaminergic neurons in vertebrates. , 2013, Human molecular genetics.

[34]  Judy H Cho,et al.  Deletion polymorphism upstream of IRGM associated with altered IRGM expression and Crohn's disease , 2008, Nature Genetics.

[35]  D. Goeddel,et al.  TRAF2-mediated activation of NF-kappa B by TNF receptor 2 and CD40 , 1995, Science.

[36]  F. Gao,et al.  Dysferlin Mediates the Cytoprotective Effects of TRAF2 Following Myocardial Ischemia Reperfusion Injury , 2014, Journal of the American Heart Association.

[37]  Chengqun Huang,et al.  Preconditioning Involves Selective Mitophagy Mediated by Parkin and p62/SQSTM1 , 2011, PloS one.

[38]  C. Culmsee,et al.  Parkin mediates neuroprotection through activation of IkappaB kinase/nuclear factor-kappaB signaling. , 2007, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[39]  Å. Gustafsson,et al.  Parkin deficiency results in accumulation of abnormal mitochondria in aging myocytes , 2013, Communicative & integrative biology.

[40]  Zhijian J. Chen,et al.  Identification and characterization of MAVS, a mitochondrial antiviral signaling protein that activates NF-kappaB and IRF 3. , 2005, Cell.

[41]  B. Viollet,et al.  Phosphorylation of ULK1 (hATG1) by AMP-Activated Protein Kinase Connects Energy Sensing to Mitophagy , 2011, Science.

[42]  R. Youle,et al.  Proteasome and p97 mediate mitophagy and degradation of mitofusins induced by Parkin , 2010, The Journal of cell biology.

[43]  H. Nakano,et al.  Tumor Necrosis Factor Receptor-associated Factor (TRAF) 2 Controls Homeostasis of the Colon to Prevent Spontaneous Development of Murine Inflammatory Bowel Disease*♦ , 2011, The Journal of Biological Chemistry.

[44]  T. Mak,et al.  PTEN-inducible kinase 1 (PINK1)/Park6 is indispensable for normal heart function , 2011, Proceedings of the National Academy of Sciences.

[45]  G Baumgarten,et al.  Endogenous tumor necrosis factor protects the adult cardiac myocyte against ischemic-induced apoptosis in a murine model of acute myocardial infarction. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[46]  Vijay G Divakaran,et al.  Tumor Necrosis Factor Receptor–Associated Factor 2 Signaling Provokes Adverse Cardiac Remodeling in the Adult Mammalian Heart , 2013, Circulation. Heart failure.

[47]  Daniel J Klionsky,et al.  Mammalian autophagy: core molecular machinery and signaling regulation. , 2010, Current opinion in cell biology.

[48]  T. Mak,et al.  TRAF2 deficiency results in hyperactivity of certain TNFR1 signals and impairment of CD40-mediated responses. , 1999, Immunity.

[49]  Zhijian J. Chen,et al.  Identification and Characterization of MAVS, a Mitochondrial Antiviral Signaling Protein that Activates NF-κB and IRF3 , 2005, Cell.