Autophagy最新文献

{"title":"A surge in endogenous spermidine is essential for rapamycin-induced autophagy and longevity.","authors":"Sebastian J Hofer, Ioanna Daskalaki, Mahmoud Abdellatif, Ulrich Stelzl, Simon Sedej, Nektarios Tavernarakis, Guido Kroemer, Frank Madeo","doi":"10.1080/15548627.2024.2396793","DOIUrl":"10.1080/15548627.2024.2396793","url":null,"abstract":"<p><p>Acute nutrient deprivation (fasting) causes an immediate increase in spermidine biosynthesis in yeast, flies, mice and humans, as corroborated in four independent clinical studies. This fasting-induced surge in spermidine constitutes the critical first step of a phylogenetically conserved biochemical cascade that leads to spermidine-dependent hypusination of EIF5A (eukaryotic translation initiation factor 5A), which favors the translation of the pro-macroautophagic/autophagic TFEB (transcription factor EB), and hence an increase in autophagic flux. We observed that genetic or pharmacological inhibition of the spermidine increase by inhibition of ODC1 (ornithine decarboxylase 1) prevents the pro-autophagic and antiaging effects of fasting in yeast, nematodes, flies and mice. Moreover, knockout or knockdown of the enzymes required for EIF5A hypusination abolish fasting-mediated autophagy enhancement and longevity extension in these organisms. Of note, autophagy and longevity induced by rapamycin obey the same rule, meaning that they are tied to an increase in spermidine synthesis. These findings indicate that spermidine is not only a \"caloric restriction mimetic\" in the sense that its supplementation mimics the beneficial effects of nutrient deprivation on organismal health but that it is also an obligatory downstream effector of the antiaging effects of fasting and rapamycin.<b>Abbreviation</b>: EIF5A: eukaryotic translation initiation factor 5A; IGF1: insulin like growth factor 1; MTOR: mechanistic target of rapamycin kinase; ODC1: ornithine decarboxylase 1; TFEB: transcription factor EB.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142115909","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":"USP8 promotes intracellular infection by enhancing ESCRT-mediated membrane repair, limiting xenophagy, and reducing oxidative stress.","authors":"Pallavi Chandra, Jennifer A Philips","doi":"10.1080/15548627.2024.2395134","DOIUrl":"10.1080/15548627.2024.2395134","url":null,"abstract":"<p><p>The host ESCRT-machinery repairs damaged endolysosomal membranes. If damage persists, selective macroautophagy/autophagy clears the damaged compartment. <i>Mycobacterium tuberculosis</i> (Mtb) is an intracellular pathogen that damages the phagosomal membrane and targets ESCRT-mediated repair as part of its virulence program. The E3 ubiquitin ligases PRKN and SMURF1 promote autophagic capture of damaged, Mtb-containing phagosomes. Because ubiquitination is a reversible process, we anticipated that host deubiquitinases (DUBs) would also be involved. Here, we screened all predicted mouse DUBs for their role in ubiquitin targeting and control of intracellular Mtb. We show that USP8 (ubiquitin specific peptidase 8) colocalizes with intracellular Mtb, recognizes phagosomal membrane damage, and is required for ESCRT-dependent membrane repair. Furthermore, we show that USP8 regulates the NFE2L2/NRF2-dependent antioxidant signature. Taken together, our study demonstrates a central role of USP8 in promoting Mtb intracellular growth by promoting phagosomal membrane repair, limiting ubiquitin-driven selective autophagy, and reducing oxidative stress.<b>Abbreviation:</b> BMDMs: bone marrow-derived macrophages; CFUs: colony-forming units; DUB: deubiquitinase; ESCRT: endosomal sorting complexes required for transport; LLOMe: L-leucyl-L-leucine methyl ester; MFI: mean fluorescence intensity; MOI: multiplicity of infection; Mtb: <i>Mycobacterium tuberculosis</i>; NFE2L2/NRF2: nuclear factor, erythroid derived 2, like 2; PMA: phorbol 12-myristate 13-acetate; ROS: reactive oxygen species; USP8: ubiquitin specific peptidase 8.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142047647","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":"Impaired degradation of PLCG1 by chaperone-mediated autophagy promotes cellular senescence and intervertebral disc degeneration.","authors":"Zhangrong Cheng, Weikang Gan, Qian Xiang, Kangcheng Zhao, Haiyang Gao, Yuhang Chen, Pengzhi Shi, Anran Zhang, Gaocai Li, Yu Song, Xiaobo Feng, Cao Yang, Yukun Zhang","doi":"10.1080/15548627.2024.2395797","DOIUrl":"10.1080/15548627.2024.2395797","url":null,"abstract":"<p><p>Defects in chaperone-mediated autophagy (CMA) are associated with cellular senescence, but the mechanism remains poorly understood. Here, we found that CMA inhibition induced cellular senescence in a calcium-dependent manner and identified its role in TNF-induced senescence of nucleus pulposus cells (NPC) and intervertebral disc degeneration. Based on structural and functional proteomic screens, PLCG1 (phospholipase C gamma 1) was predicted as a potential substrate for CMA deficiency to affect calcium homeostasis. We further confirmed that PLCG1 was a key mediator of CMA in the regulation of intracellular calcium flux. Aberrant accumulation of PLCG1 caused by CMA blockage resulted in calcium overload, thereby inducing NPC senescence. Immunoassays on human specimens showed that reduced LAMP2A, the rate-limiting protein of CMA, or increased PLCG1 was associated with disc senescence, and the TNF-induced disc degeneration in rats was inhibited by overexpression of <i>Lamp2a</i> or knockdown of <i>Plcg1</i>. Because CMA dysregulation, calcium overload, and cellular senescence are common features of disc degeneration and other age-related degenerative diseases, the discovery of actionable molecular targets that can link these perturbations may have therapeutic value.<b>Abbreviation:</b> ATRA: all-trans-retinoic acid; BrdU: bromodeoxyuridine; CDKN1A/p21: cyclin dependent kinase inhibitor 1A; CDKN2A/p16-INK4A: cyclin dependent kinase inhibitor 2A; CMA: chaperone-mediated autophagy; DHI: disc height index; ER: endoplasmic reticulum; IP: immunoprecipitation; IP3: inositol 1,4,5-trisphosphate; ITPR/IP3R: inositol 1,4,5-trisphosphate receptor; IVD: intervertebral disc; IVDD: intervertebral disc degeneration; KD: knockdown; KO: knockout; Leu: leupeptin; MRI: magnetic resonance imaging; MS: mass spectrometry; N/L: NH₄Cl and leupeptin; NP: nucleus pulposus; NPC: nucleus pulposus cells; PI: protease inhibitors; PLC: phospholipase C; PLCG1: phospholipase C gamma 1; ROS: reactive oxygen species; RT-qPCR: real-time quantitative reverse transcription PCR; SA-GLB1/β-gal: senescence-associated galactosidase beta 1; SASP: senescence-associated secretory phenotype; STV: starvation; TMT: tandem mass tag; TNF: tumor necrosis factor; TP53: tumor protein p53; UPS: ubiquitin-proteasome system.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142115911","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":"TRIM21-mediated ubiquitination of SQSTM1/p62 abolishes its Ser403 phosphorylation and enhances palmitic acid cytotoxicity.","authors":"Peng Yang, Shenglan Gao, Jianliang Shen, Tong Liu, Kevin Lu, Xinlu Han, Jun Wang, Hong-Min Ni, Wen-Xing Ding, Hong Li, Ji-An Pan, Kesong Peng, Wei-Xing Zong","doi":"10.1080/15548627.2024.2394308","DOIUrl":"10.1080/15548627.2024.2394308","url":null,"abstract":"<p><p>Long-chain free fatty acids (FFAs) accumulation and oxidative toxicity is a major cause for several pathological conditions. The mechanisms underlying FFA cytotoxicity remain elusive. Here we show that palmitic acid (PA), the most abundant FFA in the circulation, induces S403 phosphorylation of SQSTM1/p62 (sequestosome 1) and its aggregation, which sequesters KEAP1 and activates the non-canonical SQSTM1-KEAP1-NFE2L2 antioxidant pathway. The PA-induced SQSTM1 S403 phosphorylation and aggregation are dependent on SQSTM1 K7-D69 hydrogen bond formation and dimerization in the Phox and Bem1 (PB1) domain, which facilitates the recruitment of TBK1 that phosphorylates SQSTM1 S403. The ubiquitin E3 ligase TRIM21 ubiquitinates SQSTM1 at the K7 residue and abolishes the PB1 dimerization, S403 phosphorylation, and SQSTM1 aggregation. TRIM21 is oxidized at C92, C111, and C114 to form disulfide bonds that lead to its oligomerization and decreased E3 activity. Mutagenizing the three C residues to S (3CS) abolishes TRIM21 oligomerization and increases its E3 activity. TRIM21 ablation leads to decreased SQSTM1 K7 ubiquitination, hence elevated SQSTM1 S403 phosphorylation and aggregation, which confers protection against PA-induced oxidative stress and cytotoxicity. Therefore, TRIM21 is a negative regulator of SQSTM1 phosphorylation, aggregation, and the antioxidant sequestration function. TRIM21 is oxidized to reduce its E3 activity that helps enhance the SQSTM1-KEAP1-NFE2L2 antioxidant pathway. Inhibition of TRIM21 May be a viable strategy to protect tissues from lipotoxicity resulting from long-chain FFAs.<b>Abbreviations:</b> ER: endoplasmic reticulum; FFA: free fatty acid; HMOX1/HO-1: heme oxygenase 1; IB: immunoblotting; IF: immunofluorescence; IP: immunoprecipitation; KEAP1: kelch like ECH associated protein 1; MASH: metabolic dysfunction-associated steatohepatitis; MEF: mouse embryonic fibroblast; NFE2L2/Nrf2: NFE2 like BZIP transcription factor 2; PA: palmitic acid; PB1: Phox and Bem 1; ROS: reactive oxygen species; SLD: steatotic liver disease; SQSTM1: sequestosome 1; TBK1: TANK-binding kinase 1; TRIM21: tripartite motif containing 21.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142019834","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":"BIN1 deficiency enhances ULK3-dependent autophagic flux and reduces dendritic size in mouse hippocampal neurons.","authors":"Yuxi Jin, Lin Zhao, Yanli Zhang, Tingzhen Chen, Huili Shi, Huaiqing Sun, Shixin Ding, Sijia Chen, Haifeng Cao, Guannan Zhang, Qian Li, Junying Gao, Ming Xiao, Chengyu Sheng","doi":"10.1080/15548627.2024.2393932","DOIUrl":"10.1080/15548627.2024.2393932","url":null,"abstract":"<p><p>Genome-wide association studies identified variants around the <i>BIN1</i> (bridging integrator 1) gene locus as prominent risk factors for late-onset Alzheimer disease. In the present study, we decreased the expression of BIN1 in mouse hippocampal neurons to investigate its neuronal function. <i>Bin1</i> knockdown via RNAi reduced the dendritic arbor size in primary cultured hippocampal neurons as well as in mature Cornu Ammonis 1 excitatory neurons. The AAV-mediated <i>Bin1</i> RNAi knockdown also generated a significant regional volume loss around the injection sites at the organ level, as revealed by 7-Tesla structural magnetic resonance imaging, and an impaired spatial reference memory performance in the Barnes maze test. Unexpectedly, <i>Bin1</i> knockdown led to concurrent activation of both macroautophagy/autophagy and MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1). Autophagy inhibition with the lysosome inhibitor chloroquine effectively mitigated the <i>Bin1</i> knockdown-induced dendritic regression. The subsequent molecular studydemonstrated that increased expression of ULK3 (unc-51 like kinase 3), which is MTOR-insensitive, supported autophagosome formation in BIN1 deficiency. Reducing ULK3 activity with SU6668, a receptor tyrosine kinase inhibitor, or decreasing neuronal ULK3 expression through AAV-mediated RNAi, significantly attenuated <i>Bin1</i> knockdown-induced hippocampal volume loss and spatial memory decline. In Alzheimer disease patients, the major neuronal isoform of BIN1 is specifically reduced. Our work suggests this reduction is probably an important molecular event that increases the autophagy level, which might subsequently promote brain atrophy and cognitive impairment through reducing dendritic structures, and ULK3 is a potential interventional target for relieving these detrimental effects.<b>Abbreviations</b>: AV: adeno-associated virus; Aβ: amyloid-β; ACTB: actin, beta; AD: Alzheimer disease; Aduk: Another Drosophila Unc-51-like kinase; AKT1: thymoma viral proto-oncogene 1; AMPK: AMP-activated protein kinase; AP: autophagosome; BafA1: bafilomycin A₁; BDNF: brain derived neurotrophic factor; BIN1: bridging integrator 1; BIN1-iso1: BIN1, isoform 1; CA1: cornu Ammonis 1; CA3: cornu Ammonis 3; CLAP: clathrin and adapter binding; CQ: chloroquine; DMEM: Dulbecco's modified Eagle medium; EGFP: enhanced green fluorescent protein; GWAS: genome-wide association study; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MRI: magnetic resonance imaging; MTOR; mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; PET: positron emission tomography; qRT-PCR: real-time quantitative reverse transcription PCR; ROS: reactive oxygen species; RPS6KB1: ribosomal protein S6 kinase B1; TFEB: transcription factor EB; ULK1: unc-51 like kinase 1; ULK3: unc-51 like kinase 3.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142019885","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":"Phosphorylation of the selective autophagy receptor TAX1BP1 by TBK1 and IKBKE/IKKi promotes ATG8-family protein-dependent clearance of MAVS aggregates.","authors":"Jesse White, Young Bong Choi, Jiawen Zhang, Mai Tram Vo, Chaoxia He, Kashif Shaikh, Edward W Harhaj","doi":"10.1080/15548627.2024.2394306","DOIUrl":"10.1080/15548627.2024.2394306","url":null,"abstract":"<p><p>TAX1BP1 is a selective macroautophagy/autophagy receptor that inhibits NFKB and RIGI-like receptor (RLR) signaling to prevent excessive inflammation and maintain homeostasis. Selective autophagy receptors such as SQSTM1/p62 and OPTN are phosphorylated by the kinase TBK1 to stimulate their selective autophagy function. However, it is unknown if TAX1BP1 is regulated by TBK1 or other kinases under basal conditions or during RNA virus infection. Here, we found that TBK1 and IKBKE/IKKi function redundantly to phosphorylate TAX1BP1 and regulate its autophagic turnover through canonical macroautophagy. TAX1BP1 phosphorylation promotes its localization to lysosomes, resulting in its degradation. Additionally, we found that during vesicular stomatitis virus infection, TAX1BP1 is targeted to lysosomes in an ATG8-family protein-independent manner. Furthermore, TAX1BP1 plays a critical role in the clearance of MAVS aggregates, and phosphorylation of TAX1BP1 controls its MAVS aggrephagy function. Together, our data support a model whereby TBK1 and IKBKE license TAX1BP1-selective autophagy function to inhibit MAVS and RLR signaling.<b>Abbreviations:</b> ATG: autophagy related; BafA1: bafilomycin A1; CALCOCO2: calcium binding and coiled-coil domain 2; GFP: green fluorescent protein; IFA: indirect immunofluorescence assay; IFN: interferon; IκB: inhibitor of nuclear factor kappa B; IKK: IκB kinase; IRF: interferon regulatory factor; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAVS: mitochondrial antiviral signaling protein; MEF: mouse embryonic fibroblast; MOI: multiplicity of infection; IKBKG/NEMO: inhibitor of nuclear factor kappa B kinase regulatory subunit gamma; NFKB: nuclear factor kappa B; OPTN: optineurin; Poly(I:C): polyinosinic-polycytidylic acid; RB1CC1/FIP200: RB1 inducible coiled-coil 1; RIGI: RNA sensor RIG-I; RLR: RIGI-like receptor; SDD-AGE: semi-denaturing detergent-agarose gel electrophoresis; SeV: Sendai virus; SLR: SQSTM1-like receptor; SQSTM1: sequestosome 1; TAX1BP1: Tax1 binding protein 1; TBK1: TANK binding kinase 1; TNF: tumor necrosis factor; TRAF: TNF receptor associated factor; VSV: vesicular stomatitis virus; ZnF: zinc finger.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142082830","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":"Artificial targeting of autophagy components to mitochondria reveals both conventional and unconventional mitophagy pathways.","authors":"Katharina C Lorentzen, Alan R Prescott, Ian G Ganley","doi":"10.1080/15548627.2024.2395149","DOIUrl":"10.1080/15548627.2024.2395149","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Macroautophagy/autophagy enables lysosomal degradation of a diverse array of intracellular material. This process is essential for normal cellular function and its dysregulation is implicated in many diseases. Given this, there is much interest in understanding autophagic mechanisms of action in order to determine how it can be best targeted therapeutically. In mitophagy, the selective degradation of mitochondria via autophagy, mitochondria first need to be primed with signals that allow the recruitment of the core autophagy machinery to drive the local formation of an autophagosome around the target mitochondrion. To determine how the recruitment of different core autophagy components can drive mitophagy, we took advantage of the &lt;i&gt;mito&lt;/i&gt;-QC mitophagy assay (an outer mitochondrial membrane-localized tandem mCherry-GFP tag). By tagging autophagy proteins with an anti-mCherry (or anti-GFP) nanobody, we could recruit them to mitochondria and simultaneously monitor levels of mitophagy. We found that targeting ULK1, ATG16L1 and the different Atg8-family proteins was sufficient to induce mitophagy. Mitochondrial recruitment of ULK1 and the Atg8-family proteins induced a conventional mitophagy pathway, requiring RB1CC1/FIP200, PIK3C3/VPS34 activity and ATG5. Surprisingly, the mitophagy pathway upon recruitment of ATG16L1 proceeded independently of ATG5, although it still required RB1CC1 and PIK3C3/VPS34 activity. In this latter pathway, mitochondria were alternatively delivered to lysosomes via uptake into early endosomes.&lt;b&gt;Abbreviation:&lt;/b&gt; aGFP: anti-GFP nanobody; amCh: anti-mCherry nanobody; ATG: autophagy related; ATG16L1: autophagy related 16 like 1; AUTAC/AUTOTAC: autophagy-targeting chimera; BafA1: bafilomycin A&lt;sub&gt;1&lt;/sub&gt;; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CCCP: carbonyl cyanide m-chlorophenylhydrazone; COX4/COX IV: cytochrome c oxidase subunit 4; DFP: deferiprone; DMSO: dimethyl sulfoxide; GABARAP: GABA type A receptor-associated protein; GABARAPL1: GABA type A receptor associated protein like 1; HSPD1/HSP60: heat shock protein family D (Hsp60) member 1; HRP: horseradish peroxidase; HTRA2/OMI: HtrA serine peptidase 2; IB: immunoblotting; IF: immunofluorescence; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MEF: mouse embryonic fibroblast; NBR1: NBR1 autophagy cargo receptor; OMM: outer mitochondrial membrane; OPA1: OPA1 mitochondrial dynamin like GTPase; OPTN: optineurin; (D)PBS: (Dulbecco's) phosphate-buffered saline; PD: Parkinson disease; PFA: paraformaldehyde; POI: protein of interest; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; RAB: RAB, member RAS oncogene family; RB1CC1/FIP200: RB1 inducible coiled-coil 1; SQSTM1: sequestosome 1; TAX1BP1: Tax1 binding protein 1; ULK: unc-51 like autophagy activating kinase 1; VPS: vacuolar protein sorting; WIPI: WD","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037993","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":"Myotubularin 2 interacts with SEC23A and negatively regulates autophagy at ER exit sites in Arabidopsis.","authors":"Xinjing Li, Jing Zheng, Jing Su, Lin Wang, Lin Luan, Taotao Wang, Fang Bai, Qing Zhong, Qingqiu Gong","doi":"10.1080/15548627.2024.2394302","DOIUrl":"10.1080/15548627.2024.2394302","url":null,"abstract":"<p><p>Starvation- or stress-induced phosphatidylinositol 3-phosphate (PtdIns3P/PI3P) production at the endoplasmic reticulum (ER) subdomains organizes phagophore assembly and autophagosome formation. Coat protein complex II (COPII) vesicles budding from ER exit site (ERES) also contribute to autophagosome formation. Whether any PtdIns3P phosphatase functions at ERES to inhibit macroautophagy/autophagy is unknown. Here we report Myotubularin 2 (MTM2) of Arabidopsis as a PtdIns3P phosphatase that localizes to ERES and negatively regulates autophagy. MTM2 binds PtdIns3P with its PH-GRAM domain <i>in vitro</i> and acts toward PtdIns3P <i>in vivo</i>. Transiently expressed MTM2 colocalizes with ATG14b, a subunit of the phosphatidylinositol 3-kinase (PtdIns3K) complex, and overexpression of MTM2 blocks autophagic flux and causes over-accumulation of ATG18a, ATG5, and ATG8a. The <i>mtm2</i> mutant has higher levels of autophagy and is more tolerant to starvation, whereas <i>MTM2</i> overexpression leads to reduced autophagy and sensitivity to starvation. The phenotypes of <i>mtm2</i> are suppressed by <i>ATG2</i> mutation, suggesting that MTM2 acts upstream of ATG2. Importantly, MTM2 does not affect the endosomal functions of PtdIns3P. Instead, MTM2 specifically colocalizes with COPII coat proteins and is cradled by the ERES-defining protein SEC16. MTM2 interacts with SEC23A with its phosphatase domain and inhibits COPII-mediated protein secretion. Finally, a role for MTM2 in salt stress response is uncovered. <i>mtm2</i> resembles the halophyte <i>Thellungiella salsuginea</i> in its efficient vacuolar compartmentation of Na⁺, maintenance of chloroplast integrity, and timely regulation of autophagy-related genes. Our findings reveal a balance between PtdIns3P synthesis and turnover in autophagosome formation, and provide a new link between autophagy and COPII function.<b>Abbreviations</b>: ATG: autophagy related; BFA: brefeldin A; BiFC: bimolecular fluorescence complementation; CHX: cycloheximide; ConA: concanamycin A; COPII: coat protein complex II; ER: endoplasmic reticulum; ERES: ER exit site; MS: Murashige and Skoog; MTM: myotubularin; MVB: multivesicular body; PAS: phagophore assembly site; PI: phosphoinositide; TEM: transmission electron microscopy; WT: wild-type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037994","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":"Macrophage autophagy protects against acute kidney injury by inhibiting renal inflammation through the degradation of TARM1.","authors":"Xiao-Rong Huang, Lin Ye, Ning An, Chun-Yu Wu, Hong-Luan Wu, Hui-Yuan Li, Yan-Heng Huang, Qiao-Ru Ye, Ming-Dong Liu, La-Wei Yang, Jian-Xing Liu, Ji-Xin Tang, Qing-Jun Pan, Peng Wang, Lin Sun, Yin Xia, Hui-Yao Lan, Chen Yang, Hua-Feng Liu","doi":"10.1080/15548627.2024.2393926","DOIUrl":"10.1080/15548627.2024.2393926","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Macroautophagy/autophagy activation in renal tubular epithelial cells protects against acute kidney injury (AKI). However, the role of immune cell autophagy, such as that involving macrophages, in AKI remains unclear. In this study, we discovered that macrophage autophagy was an adaptive response during AKI as mice with macrophage-specific autophagy deficiency (&lt;i&gt;atg5&lt;/i&gt;&lt;sup&gt;-/-&lt;/sup&gt;) exhibited higher serum creatinine, more severe renal tubule injury, increased infiltration of ADGRE1/F4/80&lt;sup&gt;+&lt;/sup&gt; macrophages, and elevated expression of inflammatory factors compared to WT mice during AKI induced by either LPS or unilateral ischemia-reperfusion. This was further supported by adoptive transfer of &lt;i&gt;atg5&lt;/i&gt;&lt;sup&gt;-/-&lt;/sup&gt; macrophages, but not WT macrophages, to cause more severe AKI in clodronate liposomes-induced macrophage depletion mice. Similar results were also obtained in vitro that bone marrow-derived macrophages (BMDMs) lacking &lt;i&gt;Atg5&lt;/i&gt; largely increased pro-inflammatory cytokine expression in response to LPS and IFNG. Mechanistically, we uncovered that &lt;i&gt;atg5&lt;/i&gt; deletion significantly upregulated the protein expression of TARM1 (T cell-interacting, activating receptor on myeloid cells 1), whereas inhibition of TARM1 suppressed LPS- and IFNG-induced inflammatory responses in &lt;i&gt;atg5&lt;/i&gt;&lt;sup&gt;-/-&lt;/sup&gt; RAW 264.7 macrophages. The E3 ubiquitin ligases MARCHF1 and MARCHF8 ubiquitinated TARM1 and promoted its degradation in an autophagy-dependent manner, whereas silencing or mutation of the functional domains of MARCHF1 and MARCHF8 abolished TARM1 degradation. Furthermore, we found that ubiquitinated TARM1 was internalized from plasma membrane into endosomes, and then recruited by the ubiquitin-binding autophagy receptors TAX1BP1 and SQSTM1 into the autophagy-lysosome pathway for degradation. In conclusion, macrophage autophagy protects against AKI by inhibiting renal inflammation through the MARCHF1- and MARCHF8-mediated degradation of TARM1.&lt;b&gt;Abbreviations:&lt;/b&gt; AKI, acute kidney injury; ATG, autophagy related; Baf, bafilomycin A&lt;sub&gt;1&lt;/sub&gt;; BMDMs, bone marrow-derived macrophages; CCL2/MCP-1, C-C motif chemokine ligand 2; CHX, cycloheximide; CQ, chloroquine; IFNG, interferon gamma; IL, interleukin; IR, ischemia-reperfusion; MAP1LC3/LC3, microtubule-associated protein 1 light chain 3; LPS, lipopolysaccharide; MARCHF, membrane associated ring-CH-type finger; NC, negative control; NFKB, nuclear factor of kappa light polypeptide gene enhancer in B cells; NLRP3, NLR family, pyrin domain containing 3; NOS2, nitric oxide synthase 2, inducible; Rap, rapamycin; Wort, wortmannin; RT-qPCR, real-time quantitative polymerase chain reaction; Scr, serum creatinine; SEM, standard error of mean; siRNA, small interfering RNA; SYK, spleen tyrosine kinase; TARM1, T cell-interacting, activating receptor on myeloid cells 1; TAX1BP1, Tax1 (human T cell leukemia virus type I) binding protein 1; TECs, tubule epithelial cells; TNF, tumor necrosis fact","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142082828","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":"<i>Mir221-</i> and <i>Mir222</i>-enriched adsc-exosomes mitigate PM exposure-exacerbated cardiac ischemia-reperfusion injury through the modulation of the BNIP3-MAP1LC3B-BBC3/PUMA pathway.","authors":"Tzu-Lin Lee, Wen-Chi Shen, Ya-Chun Chen, Tsai-Chun Lai, Shu-Rung Lin, Shu-Wha Lin, I-Shing Yu, Yen-Hsiu Yeh, Tsai-Kun Li, I-Ta Lee, Chiang-Wen Lee, Yuh-Lien Chen","doi":"10.1080/15548627.2024.2395799","DOIUrl":"https://doi.org/10.1080/15548627.2024.2395799","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Epidemiology has shown a strong relationship between fine particulate matter (PM) exposure and cardiovascular disease. However, it remains unknown whether PM aggravates myocardial ischemia-reperfusion (I/R) injury, and the related mechanisms are unclear. Our previous study has shown that adipose stem cell-derived exosomes (ADSC-Exos) contain high levels of &lt;i&gt;Mir221&lt;/i&gt; and &lt;i&gt;Mir222&lt;/i&gt;. The present study investigated the effects of PM exposure on I/R-induced cardiac injury through mitophagy and apoptosis, as well as the potential role of &lt;i&gt;Mir221&lt;/i&gt; and &lt;i&gt;Mir222&lt;/i&gt; in ADSC-Exos. Wild-type, &lt;i&gt;mir221-&lt;/i&gt; and &lt;i&gt;mir222-&lt;/i&gt;knockout (KO), and &lt;i&gt;Mir221-&lt;/i&gt; and &lt;i&gt;Mir222-&lt;/i&gt;overexpressing transgenic (TG) mice were intratracheally injected with PM (10 mg/kg). After 24 h, mice underwent left coronary artery ligation for 30 min, followed by 3 h of reperfusion (I/R). H9c2 cardiomyocytes were cultured under 1% O&lt;sub&gt;2&lt;/sub&gt; for 6 h, then reoxygenated for 12 h (hypoxia-reoxygenation [H/R]). PM aggravated I/R (or H/R) cardiac injury by increasing ROS levels and causing mitochondrial dysfunction, which increased the expression of mitochondrial fission-related proteins (DNM1L/Drp1 and MFF) and mitophagy-related proteins (BNIP3 and MAP1LC3B/LC3B) &lt;i&gt;in vivo&lt;/i&gt; and &lt;i&gt;in vitro&lt;/i&gt;. Treatment with ADSC-Exos or &lt;i&gt;Mir221-&lt;/i&gt; and &lt;i&gt;Mir222-&lt;/i&gt;mimics significantly reduced PM+I/R-induced cardiac injury. Importantly, ADSC-Exos contain &lt;i&gt;Mir221&lt;/i&gt; and &lt;i&gt;Mir222&lt;/i&gt;, which directly targets BNIP3, MAP1LC3B/LC3B, and BBC3/PUMA, decreasing their expression and ultimately reducing cardiomyocyte mitophagy and apoptosis. The present data showed that ADSC-Exos treatment regulated mitophagy and apoptosis through the &lt;i&gt;Mir221&lt;/i&gt; and &lt;i&gt;Mir222&lt;/i&gt;-BNIP3-MAP1LC3B-BBC3/PUMA pathway and significantly reduced the cardiac damage caused by PM+I/R. The present study revealed the novel therapeutic potential of ADSC-Exos in alleviating PM-induced exacerbation of myocardial I/R injury.&lt;b&gt;Abbreviation:&lt;/b&gt; ADSC-Exos: adipose-derived stem cell exosomes; AL: autolysosome; ATP: adenosine triphosphate; BBC3/PUMA: BCL2 binding component 3; BNIP3: BCL2/adenovirus E1B interacting protein 3; CASP3: caspase 3; CASP9: caspase 9; CDKN1B/p27: cyclin dependent kinase inhibitor 1B; CVD: cardiovascular disease; DCFH-DA: 2',7'-dichlorodihydrofluorescein diacetate; DHE: dihydroethidium; DNM1L/Drp1: dynamin 1-like; EF: ejection fraction; FS: fractional shortening; H/R: hypoxia-reoxygenation; I/R: ischemia-reperfusion; LDH: lactate dehydrogenase; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MFF: mitochondrial fission factor; miRNA: microRNA; NAC: N-acetylcysteine; OCR: oxygen consumption rate; PIK3C3/Vps34: phosphatidylinositol 3-kinase catalytic subunit type 3; PM: particulate matter; PRKAA1/AMPK: protein kinase AMP-activated catalytic subunit alpha 1; ROS: reactive oxygen species; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TRP53/p53: tran","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142156930","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}