Autophagy最新文献

{"title":"Urolithin a modulates inter-organellar communication via calcium-dependent mitophagy to promote healthy ageing.","authors":"Antonis Roussos, Katerina Kitopoulou, Fivos Borbolis, Christina Ploumi, Despoina D Gianniou, Zhiquan Li, Haijun He, Eleni Tsakiri, Helena Borland, Ioannis K Kostakis, Martina Samiotaki, Ioannis P Trougakos, Vilhelm A Bohr, Konstantinos Palikaras","doi":"10.1080/15548627.2025.2561073","DOIUrl":"https://doi.org/10.1080/15548627.2025.2561073","url":null,"abstract":"<p><p>Mitochondrial dysfunction and impaired mitophagy are hallmarks of aging and age-related pathologies. Disrupted inter-organellar communication among mitochondria, endoplasmic reticulum (ER), and lysosomes, further contributes to cellular dysfunction. While mitophagy has emerged as a promising target for neuroprotection and geroprotection, its potential to restore age-associated defects in organellar crosstalk remains unclear. Here, we show that mitophagy deficiency deregulates the morphology and homeostasis of mitochondria, ER and lysosomes, mirroring age-related alterations. In contrast, urolithin A (UA), a gut-derived metabolite and potent mitophagy inducer, restores inter-organellar communication via calcium signaling, thereby, promoting mitophagy, healthspan and longevity. Our multi-omic analyses reveal that UA reorganizes ER, mitochondrial and lysosomal networks, linking inter-organellar dynamics to mitochondrial quality control. In <i>C. elegans</i>, UA induces calcium release from the ER, enhances lysosomal activity, and drives DRP-1/DNM1L/DRP1-mediated mitochondrial fission, culminating in efficient mitophagy. Calcium chelation abolishes UA-induced mitophagy, blocking its beneficial impact on muscle function and lifespan, underscoring the critical role of calcium signaling in UA's geroprotective effects. Furthermore, UA-induced calcium elevation activates mitochondrial biogenesis via UNC-43/CAMK2D and SKN-1/NFE2L2/Nrf2 pathways, which are both essential for healthspan and lifespan extension. Similarly, in mammalian cells, UA increases intracellular calcium, enhances mitophagy and mitochondrial metabolism, and mitigates stress-induced senescence in a calcium-dependent manner. Our findings uncover a conserved mechanism by which UA-induced mitophagy restores inter-organellar communication, supporting cellular homeostasis and organismal health.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":""},"PeriodicalIF":14.3,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145056179","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":"Evolutionary diversification of the autophagy initiation complex: reduced Atg101 dependency and changes in Atg9 binding to Atg13.","authors":"Zefeng Lai, Yutaro Hama, Masahide Oku, Sidi Zhang, Yasuyoshi Sakai, Hayashi Yamamoto, Noboru Mizushima","doi":"10.1080/15548627.2025.2559683","DOIUrl":"https://doi.org/10.1080/15548627.2025.2559683","url":null,"abstract":"<p><p>Macroautophagy/autophagy is an evolutionarily conserved process through which cells degrade cytoplasmic substances via autophagosomes. During the initiation of autophagosome formation, the ULK/Atg1 complex serves as a scaffold that recruits and regulates downstream ATG/Atg proteins and ATG9/Atg9-containing vesicles. Despite the essential role of the ULK/Atg1 complex, its components have changed during evolution; the ULK complex in mammals consists of ULK1 (or ULK2), RB1CC1, ATG13, and ATG101, whereas the Atg1 complex in the yeast <i>Saccharomyces cerevisiae</i> lacks Atg101 but instead has Atg29 and Atg31 along with Atg17. In this study, we investigated how such changes have evolved. A BLAST analysis across the major eukaryotic clades revealed that <i>ATG101</i>, which is essential for autophagy in mammals, was lost in some Holomycota lineages after acquisition of <i>ATG29</i> and <i>ATG31</i> by their common ancestor. Additionally, the acquisition of a cap structure in Atg13 preceded the loss of <i>ATG101</i>. However, some Holomycota species have both <i>ATG101</i> and <i>ATG29-ATG31</i>, including <i>Aspergillus oryzae</i> and <i>Komagataella phaffii</i>. Yeast two-hybrid assays showed that ATG101 is required for ATG13-ATG9 interaction in mammals but dispensable in <i>A. oryzae</i>, probably because of a shift in the <i>Ao</i>Atg9-binding site in <i>Ao</i>Atg13. We found an additive effect between <i>atg101</i> and <i>atg31</i> deletions in starvation-induced autophagy in <i>K. phaffii</i>. Furthermore, both <i>Kp</i>Atg101 and <i>Kp</i>Atg31 are involved in Atg1 complex assembly in <i>K. phaffii</i>. These findings suggest that the reduced importance of Atg101 in the Atg13-Atg9 interaction and Atg1 complex assembly enabled the eventual loss of <i>ATG101</i> in some Holomycota species, including <i>S. cerevisiae</i>.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":""},"PeriodicalIF":14.3,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145034787","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":"Microautophagy: definition, classification, and the complexity of the underlying mechanisms.","authors":"Yasuyoshi Sakai, Christian Behrends, Ana Maria Cuervo, Jayanta Debnath, Masanori Izumi, Andreas Jenny, Maurizio Molinari, Shuhei Nakamura, Masahide Oku, Marisa S Otegui, Laura Santambrogio, Han-Ming Shen, Tomohiko Taguchi, Michael Thumm, Takashi Ushimaru, Zhiping Xie, Fulvio Reggiori","doi":"10.1080/15548627.2025.2559687","DOIUrl":"https://doi.org/10.1080/15548627.2025.2559687","url":null,"abstract":"<p><p>Recently, rapid progress in the field of microautophagy (MI-autophagy) revealed the existence of multiple subtypes that differ in both intracellular membrane dynamics and molecular mechanisms. As a result, a single umbrella term \"microautophagy\" has become too vague, even creating some confusion among researchers both within and outside the field. We herein describe different subtypes of MI-autophagic processes and propose a systematic approach for naming them more accurately.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":""},"PeriodicalIF":14.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145031418","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":"KDM4A-induced tumor senescence enhances the efficacy of immunotherapy by inhibiting AGT-PHB1 axis-mediated mitophagy in colorectal cancer.","authors":"Tanxing Cai, Zhenxing Liang, Zhiping Chen, Yang Li, Wei Xiao, Wenfeng Liang, Hao Xie, Huashan Liu, Ziwei Zeng, Xin Yang, Shuanglin Luo, Xiaobin Zheng, Keli Zhong, Liang Huang, Li Xiong, Liang Kang","doi":"10.1080/15548627.2025.2551680","DOIUrl":"https://doi.org/10.1080/15548627.2025.2551680","url":null,"abstract":"<p><p>Immune checkpoint inhibitors (ICIs) can re-active the immune response and induce a complete response in mismatch repair-deficient and microsatellite instability-high (dMMR/MSI-H) colorectal cancer (CRC). However, most CRCs exhibit proficient mismatch repair and microsatellite stable (pMMR/MSS) phenotypes with limited immunotherapy response because of sparse intratumoral CD8⁺ T-lymphocyte infiltration. Cellular senescence has been reported to involve immune cell infiltration through a senescence-associated secretory phenotype (SASP). However, the relationship between CRC cellular senescence and CD8⁺ T-lymphocyte infiltration remains unclear. Through integrated analysis of clinical cohorts and transcriptomic data across mismatch repair (MMR) subtypes, we identified cellular senescence as a hallmark of dMMR tumors, accompanied by elevated expression of KDM4A (lysine demethylase 4A). Clinically, KDM4A^high CDKN2A/p16^high expression correlated with improved CRC patient prognosis. Mechanistically, KDM4A upregulated AGT (angiotensinogen) expression through H3K9me3 demethylation and promoted CRC cellular senescence. Meanwhile, KDM4A-driven senescence suppressed tumor growth and enhanced intratumoral CD8⁺ T-lymphocyte infiltration via enhancing SASP-associated secretion. Furthermore, AGT disrupted PHB1 (prohibitin 1)-mediated basal mitophagy, triggering cytoplasmic mitochondrial DNA (mtDNA) accumulation that activated CGAS-STING1 signaling and enhanced SASP secretion. Crucially, KDM4A overexpression potentiated anti-PDCD1/PD1 efficacy in MSI-H CRC and reversed therapy resistance in MSS CRC. Conclusively, we established a KDM4A-AGT-PHB1 (KAP) grade system that robustly predicts immunotherapy responsiveness in pMMR CRC patients.<b>Abbreviation</b>: AGT: angiotensinogen; BafA: bafilomycin A₁; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; CRC: colorectal cancer; CDKN1A/p21: cyclin dependent kinase inhibitor 1A; CDKN2A/p16: cyclin dependent kinase inhibitor 2A; CHX: cycloheximide; Co-IP: co-immunoprecipitation; dMMR: deficient mismatch repair; EdU: 5-ethynyl-2'-deoxyuridine; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; IL6: interleukin 6; IL8: interleukin 8; IHC: immunohistochemical; KDM4A: lysine demethylase 4A; mtDNA: mitochondrial DNA; MS: mass spectrometry; NFKB/NF-κB: nuclear factor kappa B; PHB1: prohibitin 1; PHB2: prohibitin 2; PINK1: PTEN induced kinase 1; pMMR: proficient mismatch repair; PRKN/parkin: parkin RBR E3 ubiquitin protein ligase; SASP: senescence-associated secretory phenotype; SA-GLB1/β-gal: senescence-associated galactosidase beta 1; TIMM23: translocase of inner mitochondrial membrane 23; TOMM20: translocase of outer mitochondrial membrane 20; TRIM21: tripartite motif containing 21; TUBB/beta-tubulin: tubulin beta class I.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-22"},"PeriodicalIF":14.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145024824","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":"PPA2 activates MTFP1-DNM1L fission signaling to govern mitochondrial proliferation and mitophagy.","authors":"Soumya Ranjan Mishra, Priyadarshini Mishra, Kewal Kumar Mahapatra, Bishnu Prasad Behera, Gajanan Kendre, Moureq Rashed Alotaibi, Vijay Pandey, Birija Sankar Patro, Daniel J Klionsky, Sujit Kumar Bhutia","doi":"10.1080/15548627.2025.2552900","DOIUrl":"10.1080/15548627.2025.2552900","url":null,"abstract":"<p><p>The inorganic pyrophosphatase PPA2, a matrix-localized protein, maintains mitochondrial function. Here, we identified the role of PPA2 in activating mitochondrial fission signaling. We found that PPA2 overexpression promotes mitochondrial fission by upregulating the mitochondrial translocation of phosphorylated DNM1L S616. Moreover, PPA2 interacts with MTFP1, a mitochondrial inner membrane protein, to induce fission signaling; cells knocked down for MTFP1 and overexpressing PPA2 failed to induce DNM1L activation and subsequent mitochondrial fission. Furthermore, in physiological conditions, PPA2 directed mitochondrial fission at the midzone through MFF-DNM1L, leading to mitochondrial proliferation. Interestingly, during mitochondrial stress following CCCP treatment, PPA2 triggers peripheral fission through FIS1 and DNM1L to segregate parts of damaged mitochondria, which is essential for mitophagy. In addition, PPA2 utilized the C-terminal LC3-interacting region (LIR) of MTFP1 for mitophagy-mediated clearance of damaged mitochondria. In conclusion, PPA2 activates mitochondrial fission signaling through MTFP1-DNM1L and is essential in defining the site of mitochondrial fission, leading to mitochondrial proliferation or mitophagy for maintaining mitochondrial homeostasis.<b>Abbreviations:</b> CCCP: carbonyl cyanide m-chlorophenyl hydrazone; Co-IP: co-immunoprecipitation; CQ: chloroquine; IMM: inner mitochondrial membrane; LIR: LC3-interacting region; MLS: mitochondrial localization signal; mtDNA: mitochondrial DNA; OMM: outer mitochondrial membrane; RT: room temperature.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-24"},"PeriodicalIF":14.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982269","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":"LC3 and GABARAP independent autophagy of misfolded procollagen in mouse osteoblasts.","authors":"Elena Makareeva, Shakib Omari, Anna M Roberts-Pilgrim, Laura Gorrell, Bella Radant, Muthulakshmi Sellamani, Edward L Mertz, Basma Khoury, Kenneth Kozloff, Sergey Leikin","doi":"10.1080/15548627.2025.2551478","DOIUrl":"10.1080/15548627.2025.2551478","url":null,"abstract":"<p><p>Bone synthesis should depend on autophagy because over 10% of type I procollagen (PC1) - a heterotrimer of COL1A1 and COL1A2 chains and the precursor of the main bone matrix molecule - is misfolded and rerouted from osteoblast endoplasmic reticulum (ER) to lysosomes. However, osteoblast-specific macroautophagy knockouts in mice have produced only mild bone effects. To reconcile these observations, we compared how hypomorphic expression and a conditional knockout (cKO) of <i>Atg5</i> - encoding a protein required for autophagosome formation - affected <i>Col1a2</i>^G610C/+ versus wild-type <i>Col1a2</i>^+/+ osteoblasts <i>in vivo</i> and <i>in vitro</i>. The Gly610-to-Cys substitution (G610C) in the triple helical region of the COL1A2/proα2(I) chain increases PC1 misfolding, causing its accumulation in the ER, cell stress, and osteoblast malfunction. Because autophagy reroutes misfolded PC1 from the ER to lysosomes, disruption of PC1 autophagy should significantly increase osteoblast malfunction and bone pathology in <i>Col1a2</i>^G610C/+ mice. Nonetheless, the present study revealed only minor effects of the <i>atg5</i> cKO on osteoblast function and bone formation in the <i>Col1a2</i>^G610C/+ mice, like in <i>Col1a2</i>^+/+ controls. The cKO did not reduce the autophagy flux of misfolded G610C or wild-type PC1 in primary osteoblast cultures, even though the LC3 and GABARAP lipidation and therefore autophagosome formation were disrupted. Live-cell imaging in <i>atg5</i> cKO osteoblasts demonstrated that PC1 was efficiently delivered to lysosomes without LC3 via ER exit site (ERES) microautophagy. Taken together, these observations indicate that LC3- and GABARAP-independent ERES microautophagy is the primary pathway of misfolded procollagen degradation in osteoblasts both in culture and <i>in vivo</i>.<b>Abbreviations</b>: ATG5: autophagy related 5; ATG7: autophagy related 7; Baf: bafilomycin A₁; BFA: brefeldin A; BGLAP/Ocn/osteocalcin: bone gamma-carboxyglutamate protein; COL1A1/proα1(I): collagen type I alpha 1 chain; COL1A2/proα2(I): collagen type I alpha 2 chain; cKO: conditional knockout; ER: endoplasmic reticulum; ERES: ER exit site; G610C mutation: COL1A2 p.Gly706Cys replacing Gly in position 610 from the start of the triple helix with Cys; GABARAP: GABA type A receptor-associated protein; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAR: mineral apposition rate; Ob: osteoblast; Oc: osteoclast; OI: osteogenesis imperfecta; PC1: procollagen type I, a heterotrimer of two COL1A1 and one COL1A2 chains, precursor of collagen type I; PDI: protein disulfide isomerase; RB1CC1/FIP200: RB1 inducible coiled-coil 1; SP7/osterix: Sp7 transcription factor; SQSTM1/p62: sequestosome 1; WT: wild type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-16"},"PeriodicalIF":14.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982319","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":"Endothelial F3-mediated autolysosome and lipid metabolism promote resistance to anti-VEGFA therapy in metastatic colorectal cancer.","authors":"Nan Huang, Junxi Ren, Xinyue Deng, Qize Bao, Genjie Huang, Shimeng Zhi, Yuedan Li, Juan Li, Binghui Hu, Dongqiang Zeng, Huiying Sun, Wei Zeng, Min Shi, Wangjun Liao, Jianhua Wu, Na Huang","doi":"10.1080/15548627.2025.2551720","DOIUrl":"https://doi.org/10.1080/15548627.2025.2551720","url":null,"abstract":"<p><p>Patients with metastatic colorectal cancer (mCRC) to the liver exhibit poor survival rates. Chemotherapy combined with anti-vascular therapy has emerged as the standard treatment, but resistance to anti-VEGFA therapy inevitably develops. The metabolic reprogramming of tumor vascular endothelial cells (TECs) plays a crucial, yet still poorly understood, role in the development of therapeutic resistance. We identified lipid-rich and fatty acid oxidation (FAO)-activated proliferating TECs in fatty colorectal cancer liver metastasis (CRLM) that mediate resistance to anti-VEGFA treatment. The TEC-specific F3 protein inhibited the macroautophagy/autophagy-lysosome pathway through the MAPK/JNK-MAPK/ERK-TP53/p53 signaling axis, thereby prevented CPT1A protein degradation and enhanced FAO. F3 was also involved in promoting lipid uptake and lipophagy. This process promoted cellular FAO under conditions of fatty acids and anti-VEGFA stimulation. Targeting FAO proved effective in overcoming resistance to anti-VEGFA treatment. Our findings elucidated the role of lipid metabolism in therapy-resistant TECs in fatty CRLM and provided a theoretical foundation for further research on anti-VEGFA therapy resistance. Moreover, we underscored the potential of combining FAO inhibitors to enhance the efficacy of anti-angiogenic therapy.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-20"},"PeriodicalIF":14.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145024841","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 dictates PHGDH-mediated serine metabolism in a timely manner to support oocyte development.","authors":"Hainan He, Qianqian Zhang, Zhengang Fan, Hongfei Duan, Yu Wang, Bingbing Luo, Qiao Li, Junjie Liu, Delong Li, Shengya Fang, Xia Zhang, Junling Wang, Yi-Liang Miao, Jilong Zhou","doi":"10.1080/15548627.2025.2552907","DOIUrl":"10.1080/15548627.2025.2552907","url":null,"abstract":"<p><p>The metabolic co-dependence of the oocyte and surrounding granulosa cells is crucial for oocyte developmental competence. Previous research has shown that serine-glycine and its key downstream metabolites are significantly involved in the process of oocyte maturation. However, the mechanism of serine metabolism and its influence on oocyte maturation remain unclear. In this study, we demonstrate that the serine metabolism enzyme PHGDH, which mediates <i>de novo</i> serine synthesis, is highly activated in granulosa cells and plays a crucial role in maintaining their metabolic and transcriptional homeostasis. By using our previously reported granulosa cell-oocyte co-culture system, we found that macroautophagy/autophagy regulates oocyte maturation by modulating PHGDH-mediated serine metabolism in a stage-specific manner, and this regulation is mediated by CALCOCO2/NDP52-dependent selective autophagy. Additional experiments indicated that S-adenosylmethionine (SAM) is a potential downstream product of serine metabolism, and that restoring SAM significantly rescues both granulosa cell homeostasis and oocyte quality. At the molecular level, we demonstrated that SAM regulates <i>Igf1</i> expression by altering the H3K4me3 modification level in its promoter region, highlighting a serine-SAM-H3K4me3<i>-Igf1</i> regulatory axis during oocyte maturation. Finally, we demonstrated that oocyte developmental capacity depends on <i>de novo</i> serine synthesis in granulosa cells during germinal vesicle breakdown (GVBD) stage rather than on the exogenous uptake of serine, and that disruption of serine synthesis significantly affects oocyte developmental capacity. Overall, our findings reveal how serine metabolism links granulosa cells and oocytes, provides new targets for predicting oocyte quality, and may help with strategies for early diagnosis or therapeutic intervention in improving reproductive outcomes.<b>Abbreviations</b> aa: amino acid; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; COCs: cumulus-oocyte complexes; CQ: chloroquine; DEG: differentially expressed gene; GV: germinal vesicle; GVBD: germinal vesicle breakdown; IGF1: insulin-like growth factor 1; MII: metaphase II stage of meiosis; OPTN: optineurin; Pb1: first polar body: PHGDH: 3-phosphoglycerate dehydrogenase; ROS: reactive oxygen species; SAM: s-adenosylmethionine; SQSTM1/p62: sequestosome 1; Ub: ubiquitin; WT: wild-type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-20"},"PeriodicalIF":14.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982345","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":"A novel <i>C. elegans</i> model for MAPT/Tau spreading reveals genes critical for endolysosomal integrity and seeded MAPT/Tau aggregation.","authors":"Carl Alexander Sandhof, Nicole Martin, Jessica Tittelmeier, Annabelle Schlueter, Martina Pezzali, David C Schoendorf, Timo Lange, Peter Reinhardt, Janina S Ried, Siwen Liang, Gamze Uzunoglu, Laura Gasparini, Thomas R Jahn, Dagmar E Ehrnhoefer, Carmen Nussbaum-Krammer","doi":"10.1080/15548627.2025.2551676","DOIUrl":"10.1080/15548627.2025.2551676","url":null,"abstract":"<p><p>The spreading of MAPT/Tau pathology is closely associated with the progression of neurodegeneration and cognitive decline in Alzheimer disease and other tauopathies. A key event in this process is the rupture of endolysosomal vesicles following the intercellular transfer of MAPT/Tau aggregates, releasing the transferred MAPT/Tau species into the cytosol where they can promote the aggregation of endogenous MAPT/Tau. However, understanding of the cellular pathways involved in this process remains limited. In this study, we investigated cellular pathways that prevent endolysosomal vesicle rupture. We established a new <i>C. elegans</i> model of MAPT/Tau spreading by introducing an mCherry-labeled, disease-associated aggregation-prone fragment of human MAPT/Tau (F3ΔK281::mCh) into the six touch receptor neurons. F3ΔK281::mCh transgenic animals exhibited significant neurotoxicity and mechanosensory deficits due to the accumulation of this MAPT/Tau fragment. In addition, its intercellular transmission compromised the endolysosomal system in receiving hypodermal cells. Using this model, we conducted an unbiased genome-wide RNAi screen and identified 59 genes critical for maintaining endolysosomal integrity. GO-term analysis revealed an enrichment of genes related to the ESCRT complex, the ubiquitin-proteasome system, mRNA splicing, and fatty acid metabolism. Silencing of selected conserved genes exacerbated seeded MAPT/Tau aggregation in a human induced pluripotent stem cell (hiPSC)-derived cortical neuron model and triggered endolysosomal rupture in HEK293T cells, confirming the crucial role of endolysosomal damage in seeded MAPT/Tau aggregation. Overall, this study discovered novel cellular pathways that safeguard endolysosomal integrity. These findings may guide the development of therapeutics that improve endolysosomal integrity to halt the progression of MAPT/Tau pathology.<b>Abbreviations</b>: AD: Alzheimer disease; ALM: anterior lateral microtubule cell; AVM: anterior ventral microtubule cell; BWM: body wall muscle; <i>C. elegans</i>: <i>Caenorhabditis elegans</i>; DA: dopaminergic; hiPSC: human induced pluripotent stem cell; LGALS3: galectin 3; MAPT/Tau: microtubule associated protein tau; mCh: monomeric Cherry; PD: Parkinson disease; PLM: posterior lateral microtubule cell; PVM: posterior ventral microtubule cell; sfGFP: superfolder green flourescent protein; SNCA: synuclein alpha; nt-cntrl: non-targeting siRNA; rPHFs: recombinant paired helical filaments.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-19"},"PeriodicalIF":14.3,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982263","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":"Reconstitution of autophagic-like membrane tethering reveals that Atg11 can bind and cluster vesicles on cargo mimetics.","authors":"Devika Andhare, Sarah Katzenell, Sarah I Najera, Sylvie C Mauras, Katherine M Bauer, Michael J Ragusa","doi":"10.1080/15548627.2025.2551678","DOIUrl":"10.1080/15548627.2025.2551678","url":null,"abstract":"<p><p>Macroautophagy (hereafter, autophagy) is essential for the degradation of mitochondria from yeast to humans. Mitochondrial autophagy in yeast is initiated when the selective autophagy scaffolding protein Atg11 is recruited to mitochondria through its interaction with the selective autophagy receptor Atg32. This also results in the recruitment of small 30-nm vesicles that fuse to generate the initial phagophore membrane. We demonstrate that Atg11 can bind to autophagic-like membranes in vitro in a curvature-dependent manner in part via a predicted amphipathic helix. Deletion of the amphipathic helix from Atg11 results in a delay in the formation of mitophagy initiation sites in yeast. Furthermore, using a novel biochemical approach, we demonstrate that the interaction between Atg11 and Atg32 results in the tethering of autophagic-like vesicles in clusters to giant unilamellar vesicles containing a lipid composition designed to mimic the outer mitochondrial membrane. We also demonstrate that the N-terminal region of Atg11 is an important mediator of vesicle tethering to cargo mimetics and that clustering of autophagic-like vesicles requires the C-terminal region of Atg11. Taken together, our results reveal that Atg11 clusters into high-order oligomers, can tether autophagic-like membranes and due to its ability to oligomerize can cluster vesicles on the surface of cargo mimetics. This work provides new insight into the mechanisms of protein and membrane clustering by Atg11. Given the increasing importance of protein oligomerization and clustering in autophagy, these results have important implications in the initiation of mitochondrial autophagy.<b>Abbreviations</b> Atg11: autophagy related 11; Atg11-Cterm: C-terminal region of Atg11; Atg11-Nterm: N-terminal region of Atg11; Atg32: autophagy related 32; COV: coefficient of variance; DOPC: 1,2-dioleoyl-sn-glycero-3-phosphocholine; DOPE: 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine; DOPS: 1,2-dioleoyl-sn-glycero-3-phospho-L-serine; FRAP: fluorescence recovery after photobleaching; GLT: GUV and liposome tethering; GUV: giant unilamellar vesicle; MKO: multiple knockout; OMM: outer mitochondrial membrane; PC: phosphatidylcholine; PE: phosphatidylethanolamine; PtdIns: phosphatidylinositol; PtdIns3P: phosphatidylinositol-3-phosphate; RhPE: rhodamine phosphatidylethanolamine; SAR: selective autophagy receptor; SEC: size-exclusion chromatography; SLB: supported lipid bilayers; SMrT: supported membrane templates; YPL: yeast polar lipids.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-20"},"PeriodicalIF":14.3,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144982336","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}