Autophagy induced by DAMPs facilitates the inflammation response in lungs undergoing ischemia-reperfusion injury through promoting TRAF6 ubiquitination.
Lung ischemia-reperfusion (I/R) injury remains one of the most common complications after various cardiopulmonary surgeries. The inflammation response triggered by the released damage-associated molecular patterns (DAMPs) aggravates lung tissue damage. However, little is known about the role of autophagy in the pathogenesis of lung I/R injury. Here, we report that a variety of inflammation-related and autophagy-associated genes are rapidly upregulated, which facilitate the inflammation response in a minipig lung I/R injury model. Left lung I/R injury triggered inflammatory cytokine production and activated the autophagy flux as evidenced in crude lung tissues and alveolar macrophages. This was associated with the release of DAMPs, such as high mobility group protein B1 (HMGB1) and heat shock protein 60 (HSP60). Indeed, treatment with recombinant HMGB1 or HSP60 induced autophagy in alveolar macrophages, whereas autophagy inhibition by knockdown of ATG7 or BECN1 markedly reduced DAMP-triggered production of inflammatory cytokines including IL-1β, TNF and IL12 in alveolar macrophages. This appeared to be because of decreased activation of MAPK and NF-κB signaling. Furthermore, knockdown of ATG7 or BECN1 inhibited Lys63 (K63)-linked ubiquitination of TNF receptor-associated factor 6 (TRAF6) in DAMP-treated alveolar macrophages. Consistently, treatment with 3-MA inhibited K63-linked ubiquitination of TRAF6 in I/R-injured lung tissues in vivo. Collectively, these results indicate that autophagy triggered by DAMPs during lung I/R injury amplifies the inflammatory response through enhancing K63-linked ubiquitination of TRAF6 and activation of the downstream MAPK and NF-κB signaling.
National Key Laboratory of Medical Immunology and Institute of Immunology, Second Military Medical University, Shanghai 200433, China.
Xingguang
X
Liu
Key Laboratory of Arrhythmias of the Ministry of Education of China & Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
Hao
H
Cao
Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.
Jian
J
Li
Key Laboratory of Arrhythmias of the Ministry of Education of China & Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
Bo
B
Wang
Department of Hematology, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou 510010, China.
Peng
P
Zhang
School of Medicine and Public Health, University of Newcastle, Callaghan, NSW 2308, Australia.
Xu
X
Dong Zhang
Key Laboratory of Arrhythmias of the Ministry of Education of China & Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
Zhongmin
Z
Liu
Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.
Hongbin
H
Yuan
Key Laboratory of Arrhythmias of the Ministry of Education of China & Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
Zhenzhen
Z
Zhan
D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects; D000071186:Beclin-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002478:Cells, Cultured; D018834:Chaperonin 60 / Q000235:genetics / Q000378:metabolism; D024243:HMGB1 Protein / Q000235:genetics / Q000378:metabolism; D007249:Inflammation; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008168:Lung / Q000378:metabolism / Q000473:pathology*; D016676:Macrophages, Alveolar / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology*; D015398:Signal Transduction / Q000187:drug effects; D013552:Swine; D048029:TNF Receptor-Associated Factor 6 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination / Q000187:drug effects
D000071186:Beclin-1; D018834:Chaperonin 60; D024243:HMGB1 Protein; D015850:Interleukin-6; D048029:TNF Receptor-Associated Factor 6; D014409:Tumor Necrosis Factor-alpha; C025946:3-methyladenine; D000225:Adenine