Autophagy最新文献

{"title":"ATG2A-WDR45/WIPI4-ATG9A complex-mediated lipid transfer and equilibration during autophagosome formation.","authors":"Yang Wang, Goran Stjepanovic","doi":"10.1080/15548627.2025.2473388","DOIUrl":"https://doi.org/10.1080/15548627.2025.2473388","url":null,"abstract":"<p><p>Macroautophagy/autophagy is a highly conserved cellular process, spanning from yeast to humans, and plays a vital role in maintaining cellular homeostasis. Dysregulation of autophagy has been linked to a wide range of diseases. A hallmark of autophagy is the formation of double-membrane vesicles called autophagosomes. Autophagosome biogenesis requires a large number of phospholipids, with the endoplasmic reticulum (ER) being the main lipid source. The ATG2A-WDR45/WIPI4-ATG9A complex serves as the core machinery responsible for lipid transfer and equilibration during this process. In our recent study, we resolved the cryo-electron microscopy (cryo-EM) structures of the ATG2A-WDR45/WIPI4 and ATG2A-WDR45/WIPI4-ATG9A complexes, providing critical insights into their architecture and function. Additionally, molecular dynamics simulations were employed to investigate the mechanism by which ATG2A mediates lipid extraction from donor membranes. Our findings offer structural and mechanistic insights into the spatially coupled processes of lipid transfer and re-equilibration, which are essential for phagophore membrane expansion.<b>Abbreviation:</b> ATG: autophagy related; ATG2A: autophagy related 2A; ATG2A[NR]: ATG2A N-terminal region; ATG9A: autophagy related 9A; cryo-EM: cryo-electron microscopy; cryo-ET: cryo-electron tomography; ER: endoplasmic reticulum; PtdIns3P: phosphatidylinositol-3-phosphate; <i>Sp</i>Atg2[NR]: <i>Schizosaccharomyces pombe</i> Atg2 N-terminal region; SUVs: small unilamellar vesicles; TGN: trans-Golgi network; TMEM41B: transmembrane protein 41B; VMP1: vacuole membrane protein 1; WDR45/WIPI4: WD repeat domain 45.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kit-mediated autophagy suppression driven by a viral oncoprotein emerges as a crucial survival mechanism in Merkel cell carcinoma.","authors":"Hao Shi, Yajie Yang, Jiwei Gao, Satendra Kumar, Hong Xie, Ziqing Chen, Jiawen Lyu, Harri Sihto, Virve Koljonen, Silvia Vega-Rubin-de-Celis, Vladana Vukojevic, Filip Farnebo, Viveca Björnhagen, Anders Höög, C Christofer Juhlin, Linkiat Lee, Malin Wickström, Jürgen C Becker, John Inge Johnsen, Catharina Larsson, Weng-Onn Lui","doi":"10.1080/15548627.2025.2477385","DOIUrl":"https://doi.org/10.1080/15548627.2025.2477385","url":null,"abstract":"<p><p>The KIT/c-KIT proto-oncogene is frequently over-expressed in Merkel cell carcinoma (MCC), an aggressive skin cancer commonly caused by Merkel cell polyomavirus (MCPyV). Here, we demonstrated that truncated MCPyV-encoded large T-antigen (LT) suppressed macroautophagy/autophagy by stabilizing and sequestering KIT in the paranuclear compartment via binding VPS39. KIT engaged with phosphorylated BECN1, thereby enhancing its association with BCL2 while diminishing its interaction with the PIK3C3 complex. This process ultimately resulted in the suppression of autophagy. Depletion of KIT triggered both autophagy and apoptosis, and decreased LT expression. Conversely, blocking autophagy in KIT-depleted cells restored LT levels and rescued apoptosis. Additionally, stimulating autophagy efficiently increased cell death and inhibited tumor growth of MCC xenografts in mice. These insights into the interplay between MCPyV LT and autophagy regulation reveal important mechanisms by which viral oncoproteins are essential for MCC cell viability. Thus, autophagy-inducing agents represent a therapeutic strategy in advanced MCPyV-associated MCC.<b>Abbreviation</b>: 3-MA, 3-methyladenine; AL, autolysosome; AP, autophagosome; Baf-A1, bafilomycin A₁; BARA, β-α repeated autophagy specific domain; BH3, BCL2 homology 3 domain; CCD, coiled-coil domain; CHX, cycloheximide; Co-IP, co-immunoprecipitation; CQ, chloroquine; CTR, control; DAPI, 4',6-diamidino-2-phenylindole; EBSS, Earle's balanced salt solution; ECD, evolutionarily conserved domain; EEE, three-tyrosine phosphomimetic mutations Y229E Y233E Y352E; ER, endoplasmic reticulum; FFF, three-tyrosine non-phosphomimetic mutations; FFPE, formalin-fixed paraffin-embedded; FL, full-length; GIST, gastrointestinal stromal tumor; IB, immunoblotting; IHC, immunohistochemistry; KIT-HEK293, KIT stably expressing HEK293 cells; KRT20/CK20, keratin 20; LT, large T-antigen; LT339, MCPyV truncated LT antigen; LTco, codon-optimized MCPyV LT antigen; MCC, Merkel cell carcinoma; MCPyV^-, MCPyV-negative; MCPyV, Merkel cell polyomavirus; MCPyV⁺, MCPyV-positive; PARP1, poly(ADP-ribose) polymerase 1; PCI, pan-caspase inhibitor; PI, propidium iodide; PtdIns3K, class III phosphatidylinositol 3-kinase; PtdIns3P, phosphatidylinositol-3-phosphate; RB1, RB transcriptional corepressor 1; RTKs, receptor tyrosine kinases; KITLG/SCF, KIT ligand; sT, small T-antigen; sTco, codon-optimized MCPyV sT antigen; T-B, Tat-BECN1; T-S, Tat-scrambled; TEM, transmission electron microscopy.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-21"},"PeriodicalIF":0.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143665644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The structure-function relationship of ATE1 R-transferase of the autophagic Arg/N-degron pathway.","authors":"Su Bin Kim, Ji Su Lee, Xin Lan, Wei Huang, Derek J Taylor, Yong Tae Kwon, Yi Zhang, Chang Hoon Ji","doi":"10.1080/15548627.2025.2473393","DOIUrl":"https://doi.org/10.1080/15548627.2025.2473393","url":null,"abstract":"<p><p>ATE1 (arginyltransferase 1; EC 2.3.2) transfers the amino acid arginine (Arg) from Arg-tRNA^Arg to the N-terminal (Nt) residues of proteins, such as aspartate (Asp), glutamate (Glu), and oxidized cysteine (Cys). The resulting Nt-Arg acts as an N-degron that regulates the degradation of various biomaterials via the ubiquitin/Ub-proteasome system (UPS) or the autophagy-lysosome system (ALS). In the UPS, Arg/N-degrons are recognized by cognate N-recognins, leading to substrate ubiquitination and proteasomal degradation. In the ALS, the same degrons bind the macroautophagy/autophagy receptor SQSTM1/p62 (sequestosome 1) to facilitate self-polymerization of SQSTM1 associated with cargoes and SQSTM1 interaction with LC3-II on phagophores. A key unresolved question is why only a small subset of proteins acquires Arg/N-degrons, given the rather weak binding affinity of ATE1 for Nt-substrates. In this study, we determined the cryo-EM structures of human ATE1 in complex with Arg-tRNA^Arg and an Nt-Asp peptide. ATE1 harbors two adjacent pockets that each bind an Nt-substrate or Arg-tRNA^Arg, the latter being wrapped by a long, unstructured loop. In the apo state, two ATE1 monomers form a homodimer. ATE1 achieves the selectivity for its peptidyl-ligands through these multivalent interactions, with K_d values in the micro-molar range. These results reveal the structural principle of Nt-arginylation at the crossroads of the UPS and ALS.<b>Abbreviations</b>: ALS: autophagy-lysosome system; Arg: arginine; Asp: aspartate; ATE1: arginyltransferase 1; Cys: cysteine; CysO₂(H): Cys sulfinic acid; Glu: glutamate; Nt: N-terminal; UBR: ubiquitin protein ligase E3 component n-recognin; UPS: ubiquitin-proteasome system; ZZ: ZZ-type zinc finger.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Buddleoside alleviates nonalcoholic steatohepatitis by targeting the AMPK-TFEB signaling pathway.","authors":"Meng Chen, Guowen Liu, Zhiyuan Fang, Wenwen Gao, Yuxiang Song, Lin Lei, Xiliang Du, Xinwei Li","doi":"10.1080/15548627.2025.2466145","DOIUrl":"10.1080/15548627.2025.2466145","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Nonalcoholic steatohepatitis (NASH) is a combination of hepatic steatosis, inflammation, and fibrosis, and it often follows simple hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). However, no pharmacological treatment is currently available for NASH. Given the important role of TFEB (transcription factor EB) in regulating the macroautophagy/autophagy-lysosomal pathway, TFEB is potentially a novel therapeutic target for treatment of NASH, which function can be regulated by AMP-activated protein kinase (AMPK) and MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1). Buddleoside (Bud), a natural flavonoid compound, has recently emerged as a promising drug candidate for liver diseases. Here, we shown that Bud treatment alleviated hepatic steatosis, insulin resistance, inflammation, and fibrosis in mice fed a high-fat and high-cholesterol (HFHC) diet. Notably, Bud activated AMPK, inhibited MTORC1, and enhanced TFEB transcriptional activity as well as autophagic flux &lt;i&gt;in vivo&lt;/i&gt; and &lt;i&gt;in vitro&lt;/i&gt;. Inhibition of AMPK or knockout of hepatic &lt;i&gt;Tfeb&lt;/i&gt; abrogated the alleviation effects of Bud on hepatic steatosis, insulin resistance, inflammation, and fibrosis. Mechanistic investigation revealed that Bud bound to the PRKAB1 subunit via Val81, Arg83, and Ser108 residues and activated AMPK, thereby eliciting phosphorylation of RPTOR (regulatory associated protein of MTOR complex 1) and inhibiting the kinase MTORC1, which activated the TFEB-mediated autophagy-lysosomal pathway and further ameliorated HFHC-induced NASH in mice. Altogether, our results indicate that Bud ameliorates NASH by activating hepatic the AMPK-TFEB axis, suggesting that Bud is a potential therapeutic strategy for NASH.&lt;b&gt;Abbreviations:&lt;/b&gt; ACAC, acetyl-CoA carboxylase; ADaM, allosteric drug and metabolite; AICAR, 5-aminoimidazole-4-carboxamide1-β-D-ribofuranoside; AKT, AKT serine/threonine kinase; ALP, autophagy-lysosomal pathway; AMPK, AMP-activated protein kinase; Bud, buddleoside; CAMKK2, calcium/calmodulin dependent protein kinase kinase 2; CC, compound C; CETSA, cellular thermal shift assay; C&lt;sub&gt;max&lt;/sub&gt;, maximum concentration; CQ, chloroquine; DARTS, drug affinity responsive target stability assay; EIF4EBP1, eukaryotic translation factor 4E binding protein 1; GOT1, glutamic-oxaloacetic transaminase 1; GPT, glutamic-pyruvic transaminase; GSK3B, glycogen synthase kinase 3 beta; GTT, glucose-tolerance test; HFD, high fat diet; HFHC, high-fat and high-cholesterol; HOMA-IR, homeostasis model assessment of insulin resistance; IKBKB, inhibitor of nuclear factor kappa B kinase subunit beta; INSR, insulin receptor; ITT, insulin-tolerance test; LDH, lactate dehydrogenase; STK11, serine/threonine kinase 11; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MTORC1, MTOR complex 1; NAFLD, non-alcoholic fatty liver disease; NASH, non-alcoholic steatohepatitis; ND, normal diet; NFKB, nuclear factor kappa B; PA, palmitic acid; PSR, picrosirius r","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-19"},"PeriodicalIF":0.0,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitochondrial dynamics and quality control regulate proteostasis in neuronal ischemia-reperfusion.","authors":"Garrett M Fogo, Sarita Raghunayakula, Katlynn J Emaus, Francisco J Torres Torres, Gary Shangguan, Joseph M Wider, Maik Hüttemann, Thomas H Sanderson","doi":"10.1080/15548627.2025.2472586","DOIUrl":"10.1080/15548627.2025.2472586","url":null,"abstract":"<p><p>Mitochondrial damage and dysfunction are hallmarks of neuronal injury during cerebral ischemia-reperfusion (I/R). Critical mitochondrial functions including energy production and cell signaling are perturbed during I/R, often exacerbating damage and contributing to secondary injury. The integrity of the mitochondrial proteome is essential for efficient function. Mitochondrial proteostasis is mediated by the cooperative forces of mitophagy and intramitochondrial proteolysis. The aim of this study was to elucidate the patterns of mitochondrial protein dynamics and their key regulators during an <i>in vitro</i> model of neuronal I/R injury. Utilizing the MitoTimer reporter, we quantified mitochondrial protein oxidation and turnover during I/R injury, highlighting a key point at 2 h reoxygenation for aged/oxidized protein turnover. This turnover was found to be mediated by both LONP1-dependent proteolysis and PRKN/parkin-dependent mitophagy. Additionally, the proteostatic response of neuronal mitochondria is influenced by both mitochondrial fusion and fission machinery. Our findings highlight the involvement of both mitophagy and intramitochondrial proteolysis in the response to I/R injury.<b>Abbreviations</b>: cKO: conditional knockout; CLPP: caseinolytic mitochondrial matrix peptidase proteolytic subunit; DIV: days <i>in vitro</i>; DNM1L/DRP1: dynamin 1 like; ETC: electron transport chain; hR: hours after reoxygenation; I/R: ischemia-reperfusion; LONP1: lon peptidase 1, mitochondrial; mtUPR: mitochondrial unfolded protein response; OGD: oxygen glucose deprivation; OGD/R: oxygen glucose deprivation and reoxygenation; OPA1: OPA1 mitochondrial dynamin like GTPase; PINK1: PTEN induced kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; ROI: region of interest; WT: wild-type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-15"},"PeriodicalIF":0.0,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143525500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cleavage of the selective autophagy receptor NBR1 by the PDCoV main protease NSP5 impairs autophagic degradation of the viral envelope protein.","authors":"Ke Li, Dong Chen, Kangli Zhao, Dan Liu, Dongni Kong, Yu Sun, Aohan Guan, Peng Zhou, Hui Jin, Anan Jongkaewwattana, Sizhu Suolang, Dang Wang, Hongbo Zhou, Rui Luo","doi":"10.1080/15548627.2025.2474576","DOIUrl":"10.1080/15548627.2025.2474576","url":null,"abstract":"<p><p>Porcine deltacoronavirus (PDCoV) is an emerging enteropathogenic coronavirus that causes severe diarrhea in neonatal piglets worldwide and presents a significant public health threat due to its potential for cross-species transmission. Selective macroautophagy/autophagy, mediated by autophagy receptors such as NBR1 (NBR1 autophagy cargo receptor), plays a key role in restricting viral infection and modulating the host immune response. In this study, we revealed that overexpression of NBR1 inhibits PDCoV replication, while its knockdown increases viral titers. Further analysis demonstrated that NBR1 interacts with the PDCoV envelope (E) protein independently of ubiquitination, directing it to phagophores for autophagic degradation to limit viral proliferation. To counteract this defense, PDCoV 3C-like protease, encoded by NSP5, cleaves porcine NBR1 at glutamine 353 (Q353), impairing its selective autophagy function and antiviral activity. Additionally, we demonstrated that NSP5 proteases from other coronaviruses including PEDV, TGEV, and SARS-CoV-2 also cleave NBR1 at the same site, suggesting that coronaviruses employ a conserved strategy of NSP5-mediated cleavage of NBR1 to evade host antiviral responses and facilitate infection. Overall, our study underscores the importance of NBR1-mediated selective autophagy in the host's defense against PDCoV and reveals a strategy by which PDCoV evades autophagic mechanisms to promote successful infection.<b>Abbreviation</b>: Cas9: CRISPR-associated protein 9; CC1: coiled-coil 1; Co-IP: co-immunoprecipitation; CRISPR: clustered regularly interspaced short palindromic repeats; GFP: green fluorescent protein; IFA: indirect immunofluorescence assay; KO: knockout; LIR: MAP1LC3/LC3-interacting region; mAb: monoclonal antibody; NBR1: NBR1 autophagy cargo receptor; NBR1-C: C-terminal fragment of NBR1; NBR1-N: N-terminal fragment of NBR1; OPTN: optineurin; pAb: polyclonal antibody; PB1: Phox/BEM1 domain; PDCoV: porcine deltacoronavirus; PEDV: porcine epidemic diarrhea virus; Q353A: a NBR1 construct with the glutamine (Q) residue at position 353 replaced with glutamic acid (A); SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; SQSTM1: sequestosome 1; TCID₅₀: 50% tissue culture infective dose; TGEV: porcine transmissible gastroenteritis virus; UBA: ubiquitin-associated domain; Ub: ubiquitin; WT: wild type; ZZ: ZZ-type zinc finger domain.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-16"},"PeriodicalIF":0.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"To degrade or not to degrade: how phase separation modulates selective autophagy.","authors":"Mariya Licheva, Riccardo Babic, Jeremy Pflaum, Hector Mancilla, Florian Wilfling, Claudine Kraft","doi":"10.1080/15548627.2025.2476025","DOIUrl":"10.1080/15548627.2025.2476025","url":null,"abstract":"<p><p>Selective macroautophagy/autophagy relies on newly formed double-membrane compartments, known as phagophores, to sequester and recycle diverse cellular components, including organelles, biomolecular condensates and protein aggregates, maturing into autophagosomes that fuse with the vacuole/lysosome. Autophagosomes originate at the cargo-vacuole/ER interface, where autophagy factors assemble into the phagophore assembly site (PAS). However, how autophagy proteins organize on the surface of structurally and biophysically different cargoes, and achieve spatial confinement at the PAS to support autophagosome formation remains unclear. Mechanisms governing cargo selection are also poorly understood. In this study, we demonstrate that receptor mobility, driven by low affinity cargo-receptor interactions, is crucial for rendering cellular structures degradable by autophagy. We show that cargo surface mobility, combined with the phase separation of scaffold proteins, drives the formation of early PAS precursors, termed \"initiation hubs\". These hubs dynamically rearrange at the cargo-vacuole/ER interface to promote autophagosome biogenesis, providing new insights into selective autophagy initiation.<b>Abbreviation:</b> Ape1: aminopeptidase I; Atg: autophagy related; Cvt pathway: cytoplasm-to-vacuole targeting pathway; GBP-GFP: GFP binding protein-Green Fluorescent Protein; ENDs: Ede1-dependent endocytic protein deposits; ER: endoplasmic reticulum; PAS: phagophore-assembly site; RB1CC1/FIP200: RB1-inducible coiled-coil 1; SQSTM1/p62: sequestosome 1; ULK1: unc-51 like kinase 1.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143574914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LAMP2-FLOT2 interaction enhances autophagosome-lysosome fusion to protect the septic heart in response to ILC2.","authors":"Rongjiao Shao, Weizhuo Liu, Yuxiao Feng, Xiaoyu Guo, Zhenyu Ren, Xumin Hou, Bin He","doi":"10.1080/15548627.2025.2469207","DOIUrl":"https://doi.org/10.1080/15548627.2025.2469207","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Cardiac dysfunction is a serious complication of sepsis-induced multiorgan failure in intensive care units and is characterized by an uncontrolled immune response to overwhelming infection. Type 2 innate lymphoid cells (ILC2s), as a part of the innate immune system, play a crucial role in the inflammatory process of heterogeneous cardiac disorders. However, the role of ILC2 in regulating sepsis-induced cardiac dysfunction and its underlying mechanism remain unknown. The present study demonstrated that autophagic flux blockage exacerbated inflammatory response and cardiac dysfunction, which was associated with mortality of sepsis. Using a cecal ligation and puncture (CLP) mouse sepsis model, we observed an expansion of ILC2s in the septic heart. Furthermore, IL4 derived from ILC2 mitigated cardiac inflammatory responses and improved cardiac function during sepsis. Additionally, IL4 enhanced LAMP2 (lysosomal associated membrane protein 2) expression through STAT3 (signal transducer and activator of transcription 3) activation to stabilize lysosomal homeostasis and rescue the impaired autophagic flux during sepsis. Notably, LAMP2 was preferentially bound to FLOT2 (flotillin 2) after IL4 exposure, and the interaction enhanced autophagosome-lysosome fusion in cardiac endothelial cells. Loss of FLOT2 reversed the regulatory effects of LAMP2 on autophagy mediated by IL4, leading to autophagosome accumulation and suppressed autophagosome clearance. Conclusively, these findings provide novel insights that ILC2 regulates incomplete autophagic flux to protect septic heart and expand our understanding of immunoregulation for sepsis.&lt;b&gt;Abbreviation&lt;/b&gt;: ACTB: actin beta; ACTN: actinin, alpha; ADGRE1/F4/80: adhesion G protein-coupled receptor E1; ANXA5/annexin V: annexin A5; AO: acridine orange; BECN1/Beclin1: beclin 1, autophagy related; CKM: creatine kinase, muscle; CKB: creatine kinase, brain; CLP: cecal ligation and puncture; CO: cardiac output; CQ: chloroquine; CTS: cathepsin; DAPI: 4'6-diamidino-2-phenylindole; EC: endothelial cell; EF: ejection fraction; ELISA: enzyme-linked immunosorbent assay; FLOT: flotillin; FS: fractional shortening; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GATA3: GATA binding protein 3; GLB1/β-Gal: galactosidase, beta 1; HCMEC: human cardiac microvascular endothelial cell; IL: interleukin; ILC: innate lymphoid cell; IL1RL1/ST2: interleukin 1 receptor-like 1; IL4c: IL4 complex; IL7R/CD127: interleukin 7 receptor; KEGG: Kyoto Encyclopedia of Genes and Genomes; LAMP: lysosomal-associated membrane protein; LDH: lactate dehydrogenase; LMP: lysosome membrane permeabilization; LPS: lipopolysaccharide; LVEDd: left ventricular end-diastole diameter; LVEDV: left ventricular end-diastole volume; LVESd: left ventricular end-systolic diameter; LVESV: left ventricular end-systole volume; MAN: mannosidase alpha; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MS: mass spectrometry; PECAM1/CD31: platelet/endothelial cel","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-23"},"PeriodicalIF":0.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cancer-associated mutations in autophagy-related proteins analyzed in yeast and human cells.","authors":"Yuchen Lei, Louise Uoselis, Dimitra Dialynaki, Ying Yang, Michael Lazarou, Daniel J Klionsky","doi":"10.1080/15548627.2025.2471142","DOIUrl":"10.1080/15548627.2025.2471142","url":null,"abstract":"<p><p>Macroautophagy/autophagy is a conserved process among eukaryotes and is essential to maintain cell homeostasis; the dysregulation of autophagy has been linked with multiple human diseases, including cancer. However, not many studies have focused on the cancer-related mutations in ATG (autophagy related) proteins, which are likely to affect the protein function, influence autophagy activity and further contribute to the progression of the disease. In this study, we focused on the four ATG4 isoforms, which have a higher mutation frequency compared with the other core ATG proteins (i.e. those involved in autophagosome formation). We first studied the mutations in conserved residues and characterized one cancer-associated mutation that significantly impairs protein function and autophagy activity. Extending the study, we determined a region around the mutant residue to be essential for protein function, which had yet to be examined in previous studies. In addition, we created a yeast system expressing the human ATG4B protein to study mutations in the residues that are not conserved from human to yeast. Using this yeast model, we identified six cancer-associated mutations affecting autophagy. The effects of these mutations were further tested in mammalian cells using a quadruple <i>ATG4</i> gene knockout cell line. Our study proves the principle of using human disease-associated mutations to study Atg proteins in yeast and generates a yeast tool that is helpful for a rapid screen of mutations to determine the autophagy phenotype, providing a new perspective in studying autophagy and its relation with cancer.<b>Abbreviations:</b> 4KO: <i>ATG4</i> tetra knockout; ATG: autophagy related; BafA1: bafilomycin A₁; GFP: green fluorescent protein; LC3-II: PE-conjugated form of LC3B; ORF: open reading frame; PE: phosphatidylethanolamine; RFP: red fluorescent protein; SEP: superecliptic pHluorin; Ubl: ubiquitin-like; UCEC: uterine corpus endometrial carcinoma.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-17"},"PeriodicalIF":0.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143525496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Autophagy induced by mechanical stress sensitizes cells to ferroptosis by NCOA4-FTH1 axis.","authors":"Chenyu Luo, Haisheng Liang, Mintao Ji, Caiyong Ye, Yiping Lin, Yuhan Guo, Zhisen Zhang, Yinyin Shu, Xiaoni Jin, Shuangshuang Lu, Wanling Lu, Yazheng Dang, Hong Zhang, Bingyan Li, Guangming Zhou, Zengli Zhang, Lei Chang","doi":"10.1080/15548627.2025.2469129","DOIUrl":"10.1080/15548627.2025.2469129","url":null,"abstract":"<p><p>Ferroptosis is an iron-dependent regulated form of cell death implicated in various diseases, including cancers, with its progression influenced by iron-dependent peroxidation of phospholipids and dysregulation of the redox system. Whereas the extracellular matrix of tumors provides mechanical cues influencing tumor initiation and progression, its impact on ferroptosis and its mechanisms remains largely unexplored. In this study, we reveal that heightened mechanical tension sensitizes cells to ferroptosis, whereas decreased mechanics confers resistance. Mechanistically, reduced mechanical tension reduces intracellular free iron levels by enhancing FTH1 protein expression. Additionally, low mechanics significantly diminishes NCOA4, pivotal in mediating FTH1 phase separation-induced ferritinophagy. Targeting NCOA4 effectively rescues ferroptosis susceptibility under low mechanical tension through modulation of FTH1 phase separation-driven autophagy. In conclusion, our findings demonstrate that mechanics regulates iron metabolism via NCOA4-FTH1 phase separation-mediated autophagy, thereby influencing ferroptosis sensitivity and offering promising therapeutic avenues for future exploration.<b>Abbreviations:</b> ACO1: aconitase 1; ATG5: autophagy related 5; DMSO: dimethyl sulfoxide; EGFP: enhanced green fluorescent protein; FACS: fluorescence-activated cell sorting; FER-1: ferrostatin-1; FTH1: ferritin heavy chain 1; FTL: ferritin light chain; GPX4: glutathione peroxidase 4; IR: ionizing radiation; IREB2: iron responsive element binding protein 2; NCOA4: nuclear receptor coactivator 4; NFE2L2: NFE2 like bZIP transcription factor 2; NOPP: norepinephrine; PBS: phosphate-buffered saline; PI: propidium iodide; RSL3: (1S,3 R)-RSL3; TCGA: The Cancer Genome Atlas; WWTR1: WW domain containing transcription regulator 1; YAP1: Yes1 associated transcriptional regulator.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-20"},"PeriodicalIF":0.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143484983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}