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Parkinson's disease (PD) is indeed a complex neurodegenerative disorder recognized by the progressive depletion of dopaminergic neurons in the brain, particularly in the substantia nigra region, leading to motor impairments and other symptoms. But at the molecular level, the study about PD still lacks. As the number of cases worldwide continues to increase, it is critical to focus on the cellular and molecular mechanisms of the disease's presentation and neurodegeneration to develop novel therapeutic approaches. At the molecular level, the complexity is more due to the involvement of vacuolar protein sorting 35 (VPS35) and sonic hedgehog (SHH) signaling in PD (directly or indirectly), leading to one of the most prominent hallmarks of the disease, which is an accumulation of α-synuclein. This elevated pathogenesis may result from impaired autophagy due to mutation in the case of VPS35 and impairment in SHH signaling at the molecular level. The traditional understanding of PD is marked by the disruption of dopaminergic neurons and dopaminergic signaling, which exacerbates symptoms of motor function deficits. However, the changes at the molecular level that are being disregarded also impact the overall health of the dopaminergic system. Gaining insight into these two unique mechanisms is essential to determine whether they give neuroprotection or have no effect on the health of neurons. Hence, here we tried to simplify the understanding of the role of VPS35 and SHH signaling to comprehend it in one direction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The objective is to investigate the effects of apelin-13 in models of post-traumatic stress disorder (PTSD). Mature male CD1 mice were subjected to the single prolonged stress method to induce PTSD-related behaviors. These behaviors were then evaluated using the elevated plus maze test, Morris water maze test, and open field test. Hippocampal neural cell death was assessed using propidium iodide labeling. The expression of hippocampal autophagy pathway-associated proteins was determined through immunoblotting analysis, and LC3 levels were also measured via quantitative real-time reverse transcription-PCR. The results demonstrate that administration of apelin-13 suppressed PTSD-induced hippocampal neural cell death and alleviated PTSD-related behaviors in mice. Additionally, PTSD led to an up-regulation of LC3 and FoxO3a, and down-regulation of P62, p-PI3K, p-Akt, and p-FoxO3a in the hippocampus. However, these changes were reversed by apelin-13 treatment. These findings support the hypothesis that apelin-13 prevents the development of PTSD-like behavior and inhibits autophagy of neuronal cells in a mouse model of PTSD. Apelin-13 may hold potential as a therapeutic agent for PTSD in clinical applications., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Aims: Major depressive disorder (MDD) is an enduring and severe mood disorder. Previous studies have indicated that p75NTR is involved in neuronal survival and death. However, the specific mechanism of p75NTR in depression remains unknown. The present study aimed to explore the role and mechanism of p75NTR in depression, and try to provide a new target for the treatment of MDD., Main Methods: The p75NTR knockout and overexpression mice were used to establish a mouse model of depression induced by chronic restraint stress (CRS), and the behavioral effects and potential mechanisms associated with p75NTR knockout/overexpression on CRS-induced depressive mice were investigated by animal behavior, histopathology, immunofluorescence and western blot, respectively., Key Findings: The results demonstrate that p75NTR knockout/overexpression can ameliorate the depressive-like behaviors observed in CRS-induced depressive mice. Furthermore, p75NTR knockout/overexpression safeguards the tissue morphology of the hippocampus, inhibits the mTOR signaling pathway to restore autophagy, and modulates apoptosis-related proteins (Bcl-2 and Bax) to reestablish normal levels of autophagy and apoptosis in hippocampal neurons of depressed mice. Importantly, p75NTR knockout/overexpression can improve synaptic plasticity through protecting the dendritic structure and dendritic spines of hippocampal neurons, and upregulating the expression of hippocampal synaptic-related proteins (PSD95 and SYN1)., Significance: These findings suggest that p75NTR knockout/overexpression can alleviate CRS-induced depression-like behaviors by reinstating autophagy and suppressing apoptosis in hippocampal neurons, and enhancing hippocampal synaptic plasticity via mTOR pathway. These insights may provide potential targets for clinical treatment of depression., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Autophagy serves as a critical regulator of immune responses in sepsis. Macrophages are vital constituents of both innate and adaptive immunity. In this study, we delved into the intricate role of p120-catenin (p120) in orchestrating autophagy in macrophages in response to endotoxin stimulation. Depletion of p120 effectively suppressed LPS-induced autophagy in both J774A.1 macrophages and murine bone marrow-derived macrophages. LPS not only elevated the interaction between p120 and L chain 3 (LC3) I/II but also facilitated the association of p120 with mammalian target of rapamycin (mTOR). p120 depletion in macrophages by small interfering RNA reduced LPS-induced dissociation of mTOR and Unc-51-like kinase 1 (ULK1), leading to an increase in the phosphorylation of ULK1. p120 depletion also enhanced LPS-triggered macrophage apoptosis, as evidenced by increased levels of cleaved caspase 3, 7-aminoactinomycin D staining, and TUNEL assay. Notably, inhibiting autophagy reversed the decrease in apoptosis caused by LPS stimulation in macrophages overexpressing p120. Additionally, the ablation of p120 inhibited autophagy and accentuated apoptosis in alveolar macrophages in LPS-challenged mice. Collectively, our findings strongly suggest that p120 plays a pivotal role in fostering autophagy while concurrently hindering apoptosis in macrophages, achieved through modulation of the mTOR/ULK1 signaling pathway in sepsis. This underscores the potential of targeting macrophage p120 as an innovative therapeutic avenue for treating inflammatory disorders., (Copyright © 2024 by The American Association of Immunologists, Inc.)

Oxidative stress is a critical pathogenic factor for age-related macular degeneration (AMD). Autophagy serves as a mechanism to counteract oxidative stress. LAMTOR1 regulates mTORC1 activity by recruiting or disassembling it on the lysosome under the addition or deprivation of amino acids. This regulation inhibits or enhances autophagy. Our study investigates whether oxidative stress impacts LAMTOR1, thereby adapting to oxidative conditions. We employed oxidative stressors, menadione (VK3) and 4-hydroxynonenal (4-HNE), and observed a reduction of LAMTOR1 in both human and mouse retinal pigment epithelium (RPE) following short-term (1h) and prolonged exposures (24h). Nrf2 overexpression increased both lamtor1 mRNA and LAMTOR1 protein in the RPE. To determine if Nrf2 regulates lamtor1 transcription, we cloned the deletion mutants of the lamtor1 promoter into a luciferase reporter. Although the promoter contained antioxidant response elements, transcriptional activity depended on the interaction between Nrf2 and the constructs containing the transcriptional start site. Moreover, Nrf2-driven transcription was significantly reduced by an inhibitor of histone acetyltransferase, p300. Correspondingly, Nrf2 overexpression increased levels of acetylated histone 3 and p300. The reduction in LAMTOR1 by 4-HNE was reversed by pepstatin A and NH 4 Cl which block lysosomal degradation. 4-HNE increased TFEB nuclear translocation which was reversed by LAMTOR1 overexpression. In vivo, LAMTOR1 levels decreased in the photoreceptor and RPE layers of NaIO 3 -injected mice, compared to PBS-injected controls. In conclusion, oxidative injury reduces LAMTOR1, predominantly through lysosomal degradation although Nrf2-mediated histone acetylation enhances lamtor1 transcription. This study reveals a previously unrecognized regulatory mechanism of lamtor1 by oxidative stress, suggesting a novel role for LAMTOR1 in the pathogenesis of AMD., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, with the non-neovascular or atrophic form being the most common. Current treatment options are limited, emphasizing the urgent need for new therapeutic strategies. Our key finding is that increased levels of AKT2 in the RPE cells impair lysosomal function and trigger secretory autophagy; a non-canonical macroautophagy/autophagy pathway where cellular materials are released via the plasma membrane rather than being degraded by lysosomes. We showed that this process involves a protein complex, AKT2-SYTL1-TRIM16-SNAP23, releasing factors contributing to drusen biogenesis, a clinical hallmark of AMD development. Importantly, SIRT5 can inhibit this pathway, potentially offering a protective effect. Understanding mechanisms by which this non-canonical autophagy pathway promotes extracellular waste accumulation could provide new insights into drusen biogenesis. Future therapies for atrophic AMD could focus on regulating secretory autophagy or manipulating proteins involved in this process.

GJA1/Cx43 (gap junction protein alpha 1) has long been associated with gap junctions-mediated communication between adjacent cells. However, recent data have defied this concept, with studies implicating GJA1 in other biological processes, such as macroautophagy/autophagy regulation, mitochondrial activity and extracellular vesicles biology. In our recent study we unveiled an additional role played by GJA1 in lysosomal trafficking. We demonstrate that GJA1 promotes the exocytosis of damaged lysosomes, through a mechanism that relies on ACTR2/ARP2-ACTR3/ARP3-dependent actin remodeling. Our findings ascribe to GJA1 an important role during pathogen infection and lysosomal storage disorders, favoring the release of dysfunctional lysosomes.

Colorectal cancer (CRC) remains a leading cause of death globally despite the improvements in cancer treatment. Autophagy is an evolutionarily conserved lysosomal-dependent degradation pathway that is critical in maintaining cellular homeostasis. However, in cancer, autophagy may have conflicting functions in preventing early tumour formation versus the maintenance of advanced-stage tumours. Defective autophagy has a broad and dynamic effect not just on cancer cells, but also on the tumour microenvironment which influences tumour progression and response to treatment. To add to the layer of complexity, somatic mutations in CRC including tumour protein p53 (TP53), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), Kirsten rat sarcoma viral oncogene homolog (KRAS), and phosphatase and tensin homolog (PTEN) can render chemoresistance by promoting a pro-survival advantage through autophagy. Recent studies have also reported autophagy-related cell deaths that are distinct from classical autophagy by employing parts of the autophagic machinery, which impacts strategies for autophagy regulation in cancer therapy. This review discusses the molecular processes of autophagy in the evolution of CRC and its role in the tumour microenvironment, as well as prospective therapeutic methods based on autophagy suppression or promotion. It also highlights clinical trials using autophagy modulators for treating CRC, underscoring the importance of autophagy regulation in CRC therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Tripartite motif-containing protein 13 (TRIM13) directly or indirectly participates in autophagy and apoptosis. However, it remains unclear whether TRIM13 participates in chronic obstructive pulmonary disease (COPD) progression. This study aimed to reveal the molecular mechanisms through which TRIM13 regulates alveolar epithelial cell injury in COPD to provide new molecular targets for COPD treatment., Methods: The TRIM13 expression levels were determined in clinical COPD patients and a rat emphysema model. A cigarette smoke-induced model of endoplasmic reticulum stress (ERS) and endoplasmic reticulum autophagy (ER-phagy) was developed using A549 cells, and the effects of TRIM13 gene overexpression/knockdown on ERS, ER-phagy, and cell apoptosis were assessed in these cells., Results: TRIM13 expression was significantly decreased in the lung tissues of COPD patients and rats with emphysema. Moreover, the apoptosis level was significantly increased in the lung tissues of rats with emphysema. TRIM13 gene overexpression reduced the expression levels of ERS-related molecules (GRP78, GRP94, XBP-1, and eIF2a) in the COPD model; it also lowered the ER-phagy level, as evidenced by decreased number of autolysosomes observed by transmission electron microscopy, improved endoplasmic reticulum structure, reduced LC3-II/LC3-I and Beclin1 expression levels, and increased expression level of the autophagy inhibitory molecule Bcl-2. TRIM13 gene knockdown, however, led to opposite results., Conclusion: TRIM13 expression attenuated alveolar epithelial cell injury in COPD by inhibiting ERS-induced ER-phagy., (© 2024. The Author(s).)

Major depressive disorder (MDD) is a common and severe psychiatric disease, which does not only lead to variety of neuropsychiatric symptoms, but unfortunately in a relatively large proportion of cases also to suicide. The pathogenesis of MDD still requires definition. We have previously shown that ceramide is increased in the blood plasma of patients with MDD. In mouse models of MDD, which are induced by treatment with corticosterone or application of chronic unpredictable stress, increased blood plasma ceramide also increased and caused an inhibition of phospholipase D in endothelial cells of the hippocampus and reduced phosphatidic acid levels in the hippocampus. Here, we demonstrated that corticosterone treatment of PC12 cells resulted in reduced cellular autophagy, which is corrected by treatment with phosphatidic acid. In vivo, treatment of mice with corticosterone or chronic unpredictable stress also reduced autophagy in hippocampus neurons. Autophagy was normalized upon i.v. injection of phosphatidic acid in these mouse models of MDD. In an attempt to identify targets of phosphatidic acid in neurons, we demonstrated that corticosterone reduced levels of the ganglioside GM1 in PC-12 cells and the hippocampus of mice, which were normalized by treatment of cells or i.v. injection of mice with phosphatidic acid. GM1 application also normalized autophagy in cultured neurons. Phosphatidic acid and GM1 corrected stress-induced alterations in behavior, i.e., mainly anxiety and anhedonia, in experimental MDD in mice. Our data suggest that phosphatidic acid may regulate via GM1 autophagy in neurons., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s).)

Macroautophagy/autophagy degrades and recycles cellular constituents via the lysosome to maintain cellular homeostasis. Our study identified the endoplasmic reticulum (ER)-resident SIGMAR1 (sigma non-opioid intracellular receptor 1) as a critical regulator of the biosynthesis of Atg8-family proteins that leads to the lipidation that is essential during autophagosome formation. We demonstrate that SIGMAR1 stabilizes MAP1LC3B/LC3B and GABARAP mRNAs, promoting their localized translation proximal to the ER for efficient lipidation. Using single-molecule fluorescence in situ hybridization/smFISH and co-immunoprecipitation, we found that SIGMAR1 directly binds to a conserved region in the 3' UTR of LC3B mRNA, facilitating its translation, efficient lipidation, and proper integration into the phagophore membrane. Cells lacking SIGMAR1 show reduced levels of many Atg8-family proteins and impaired autophagic flux. Our model suggests that SIGMAR1-mediated localized translation of Atg8-family proteins at the ER promotes efficient autophagosome formation, in contrast to recruiting preexisting cytosolic Atg8-family proteins to the lipidation machinery. Elucidating the role of SIGMAR1 in autophagy may provide better therapeutic strategies to prevent or treat autophagy-dependent neurodegenerative diseases, particularly given the highly druggable nature of SIGMAR1.

A recent study in our group reports a new "condensates to VPS41-associated phagic vacuole (VAPVs) conversion pathway" that is essential for macroautophagy/autophagy degradation in plant cells. Here, we compare the autophagy process between plants and other eukaryotic systems and discuss the potential roles of biomolecular condensates and synaptic-soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins in plant autophagy.

Mitochondria are crucial organelles in maintaining cellular homeostasis. They are involved in processes such as energy production, metabolism of lipids and glucose, and cell death regulation. Mitochondrial dysfunction can lead to various health issues such as aging, cancer, neurodegenerative diseases, and chronic liver diseases. While mitophagy is the main process for getting rid of excess or damaged mitochondria, there are additional mechanisms for preserving mitochondrial quality. One such alternative mechanism we have discovered is a hybrid organelle called mitochondrial-lysosome-related-organelle (MLRO), which functions independently of the typical autophagy process. More recently, another type of vesicle called vesicle derived from the inner mitochondrial membrane (VDIM) has been identified to break down the inner mitochondrial membrane without involving the standard autophagy pathway. In this article, we will delve into the similarities and differences between MLRO and VDIM, including their structure, regulation, and relevance to human diseases.

Testosterone is secreted by Leydig cells (LCs), which play an important physiological role in preserving male secondary sex characteristics, protecting male reproductive function, and establishing the blood-testis barrier. Studies have shown that autophagy is particularly active in LCs; however, its involvement in testosterone synthesis in porcine LCs has not been fully explored. Therefore, this experiment aimed to investigate the influence of autophagy on testosterone secretion in porcine LCs and its potential regulatory mechanism. Our results demonstrated that both testicular autophagy and serum testosterone levels increased in piglets during postnatal development from 4 to 18 weeks. In addition, autophagy was found to degrade the Na + /H + exchange regulatory factor 2 (NHERF2), leading to the up-regulation of scavenger receptor class B type 1 (SRB1). This process resulted in increased cholesterol intake and enhanced testosterone production. The observable level of sirtuin 1 (SIRT1) was directly proportional to the level of autophagy. In vitro investigations have shown that SIRT1 can affect the level of autophagy, cholesterol uptake as well as testosterone release. In conclusion, testosterone synthesis during pig development is regulated by SIRT1. SIRT1 mediates the degradation of NHERF2 through autophagy, thereby weakening its negative regulatory effect on the high-density lipoprotein receptor SRB1 in Leydig cells. This process increases cholesterol uptake and enhances testosterone synthesis., Competing Interests: Competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

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. Abbreviation : 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.

Rationale: Major depression has been an area of extensive research during the last decades, for it represents a leading cause of disability and suicide. The stark rise of depression rates influenced by life stressors, economic threats, pandemic era, and resistance to classical treatments, has made the disorder rather challenging. Adult hippocampal neurogenesis and plasticity are particularly sensitive to the dynamic interplay between autophagy and inflammation. In fact, the intricate balance between the two processes contributes to neuronal homeostasis and survival., Objectives: Having demonstrated promising potentials in AMPK activation, a major metabolic sensor and autophagy regulator, empagliflozin (Empa) was investigated for possible antidepressant properties in the reserpine rat model of depression., Results: While the reserpine protocol elicited behavioral, biochemical, and histopathological changes relevant to depression, Empa outstandingly hindered these pathological perturbations. Importantly, hippocampal autophagic response markedly declined with reserpine which disrupted the AMPK/mTOR/Beclin1/LC3B machinery and, conversely, neuro-inflammation prevailed under the influence of the NLRP3 inflammasome together with oxidative/nitrative stress. Consequently, AMPK-mediated neurotrophins secretion obviously deteriorated through PKCζ/NF-κB/BDNF/CREB signal restriction. Empa restored hippocampal monoamines and autophagy/inflammation balance, driven by AMPK activation. By promoting the atypical PKCζ phosphorylation (Thr403) which subsequently phosphorylates NF-κB at Ser311, AMPK successfully reinforced BDNF/CREB signal and hippocampal neuroplasticity. The latter finding was supported by hippocampal CA3 toluidine blue staining to reveal intact neurons., Conclusion: The current study highlights an interesting role for Empa as a regulator of autophagic and inflammatory responses in the pathology of depression. The study also pinpoints an unusual contribution for NF-κB in neurotrophins secretion via AMPK/PKCζ/NF-κB/BDNF/CREB signal transduction. Accordingly, Empa can have special benefits in diabetic patients with depressive symptoms., Limitations: The influence of p-NF-κB (Ser311) on NLRP3 inflammasome assembly and activation has not been investigated, which can represent an interesting point for further research., Competing Interests: Declarations Conflict of interest The authors declared that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024. The Author(s).)

Aging is often accompanied by a decline in proteostasis, manifested as an increased propensity for misfolded protein aggregates, which are prevented by protein quality control systems, such as the ubiquitin-proteasome system (UPS) and macroautophagy/autophagy. Although the role of the UPS and autophagy in slowing age-induced proteostasis decline has been elucidated, limited information is available on how these pathways can be activated in a collaborative manner to delay proteostasis-associated aging. Here, we show that activation of the UPS via the pharmacological inhibition of USP14 (ubiquitin specific peptidase 14) using IU1 improves proteostasis and autophagy decline caused by aging or proteostatic stress in Drosophila and human cells. Treatment with IU1 not only alleviated the aggregation of polyubiquitinated proteins in aging Drosophila flight muscles but also extended the fly lifespan with enhanced locomotive activity via simultaneous activation of the UPS and autophagy. Interestingly, the effect of this drug disappeared when proteasomal activity was inhibited, but was evident upon proteostasis disruption by foxo mutation. Overall, our findings shed light on potential strategies to efficiently ameliorate age-associated pathologies associated with perturbed proteostasis. Abbreviations : AAAs: amino acid analogs; foxo: forkhead box, sub-group O; IFMs: indirect flight muscles; UPS: ubiquitin-proteasome system; USP14: ubiquitin specific peptidase 14.

Macroautophagy/autophagy plays a crucial role in inhibiting viral replication and regulating the host's immune response. The autophagy receptor SQSTM1/p62 (sequestosome 1) restricts viral replication by directing specific viral proteins to phagophores for degradation. In this study, we investigate the reciprocal relationship between Zika virus (ZIKV) and selective autophagy mediated by SQSTM1/p62. We show that NS2B3 protease encoded by ZIKV cleaves human SQSTM1/p62 at arginine 265 (R265). This cleavage also occurs with endogenous SQSTM1 in ZIKV-infected cells. Furthermore, overexpression of SQSTM1 inhibits ZIKV replication in A549 cells, while its absence increases viral titer. We have also shown that SQSTM1 impedes ZIKV replication by interacting with NS3 and NS5 and directing them to autophagic degradation, and that NS2B3-mediated cleavage could potentially alter this antiviral function of SQSTM1. Taken together, our study highlights the role of SQSTM1-mediated selective autophagy in the host's antiviral defense against ZIKV and uncovers potential viral evasion strategies that exploit the host's autophagic machinery to ensure successful infection. Abbreviation: Cas9: CRISPR-associated protein 9; Co-IP: co-immunoprecipitation; CRISPR: clustered regularly interspaced short palindromic repeats; DENV: dengue virus; GFP: green fluorescent protein; IFA: indirect immunofluorescence assay; KIR: KEAP1-interacting region; KO: knockout; LIR: MAP1LC3/LC3-interacting region; mAb: monoclonal antibody; NBR1: NBR1 autophagy cargo receptor; OPTN: optineurin; pAb: polyclonal antibody; PB1: Phox/BEM1 domain; R265A, a SQSTM1 construct with the arginine (R) residue at position 265 replaced with glutamic acid (A); SQSTM1: sequestosome 1; SQSTM1-C, C-terminal fragment of SQSTM1; SQSTM1-N, N-terminal fragment of SQSTM1; SVV: Seneca Valley virus; TAX1BP1: Tax1 binding protein 1; TBD: TRAF6-binding domain; TCID 50 : 50% tissue culture infective dose; UBA: ubiquitin-associated domain; Ub: ubiquitin; WT: wild type; ZIKV: Zika virus; ZZ: ZZ-type zinc finger domain.

Rabies virus causes an estimated 59,000 annual fatalities worldwide and promising therapeutic treatments are necessary to develop. In this study, affinity tag-purification mass spectrometry was employed to delineate RABV glycoprotein and host protein interactions, and PDIA3/ERP57 was identified as a potential inhibitor of RABV infection. PDIA3 restricted RABV infection with follow mechanisms: PDIA3 mediated the degradation of RABV G protein by targeting lysine 332 via the selective macroautophagy/autophagy pathway; The PDIA3 interactor, AP3B1 (adaptor related protein complex 3 subunit beta 1) was indispensable in PDIA3-triggered selective degradation of the G protein; Furthermore, PDIA3 competitively bound with NCAM1/NCAM (neural cell adhesion molecule 1) to block RABV G, hindering viral entry into host cells. PDIA3 190-199 aa residues bound to the RABV G protein were necessary and sufficient to defend against RABV. These results demonstrated the therapeutic potential of biologics that target PDIA3 or utilize PDIA3 190-199 aa peptide to treat clinical rabies. Abbreviation: aa: amino acids; ANXA2: annexin A2; AP-MS: affinity tag purification-mass spectrometry; AP3B1: adaptor related protein complex 3 subunit beta 1; ATP6V1A: ATPase H + transporting V1 subunit A; ATP6V1H: ATPase H + transporting V1 subunit H; BafA1: bafilomycin A1; CHX: cycloheximide; co-IP: co-immunoprecipitation; DDX17: DEAD-box helicase 17; DmERp60: drosophila melanogaster endoplasmic reticulum p60; EBOV: Zaire ebolavirus virus; EV: empty vector; GANAB: glucosidase II alpha subunit; G protein: glycoprotein; GRM2/mGluR2: glutamate metabotropic receptor 2; HsPDIA3: homo sapiens protein disulfide isomerase family A member 3; IAV: influenza virus; ILF2: interleukin enhancer binding factor 2; KO: knockout; MAGT1: magnesium transporter 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MmPDIA3: mus musculus protein disulfide isomerase associated 3; NCAM1/NCAM: neural cell adhesion molecule 1; NGFR/p75NTR: nerve growth factor receptor; NGLY1: N-glycanase 1; OTUD4: OTU deubiquitinase 4; PDI: protein disulfide isomerase; PPIs: protein-protein interactions; RABV: rabies virus; RUVBL2: RuvB like AAA ATPase 2; SCAMP3: secretory carrier membrane protein 3; ScPdi1: S accharomyces cerevisiae s288c protein disulfide isomerase 1; SLC25A6: solute carrier family 25 member 6; SQSTM1/p62: sequestosome 1; VSV: vesicular stomatitis virus.

The commonality between various muscle diseases is the loss of muscle mass, function, and regeneration, which severely restricts mobility and impairs the quality of life. With muscle stem cells (MuSCs) playing a key role in facilitating muscle repair, targeting regulators of muscle regeneration has been shown to be a promising therapeutic approach to repair muscles. However, the underlying molecular mechanisms driving muscle regeneration are complex and poorly understood. Here, we identified a new regulator of muscle regeneration, Deaf1 (Deformed epidermal autoregulatory factor-1) - a transcriptional factor downstream of foxo signaling. We showed that Deaf1 is transcriptionally repressed by FOXOs and that DEAF1 targets to Pik3c3 and Atg16l1 promoter regions and suppresses their expression. Deaf1 depletion therefore induces macroautophagy/autophagy, which in turn blocks MuSC survival and differentiation. In contrast, Deaf1 overexpression inactivates autophagy in MuSCs, leading to increased protein aggregation and cell death. The fact that Deaf1 depletion and its overexpression both lead to defects in muscle regeneration highlights the importance of fine tuning DEAF1-regulated autophagy during muscle regeneration. We further showed that Deaf1 expression is altered in aging and cachectic MuSCs. Manipulation of Deaf1 expression can attenuate muscle atrophy and restore muscle regeneration in aged mice or mice with cachectic cancers. Together, our findings unveil an evolutionarily conserved role for DEAF1 in muscle regeneration, providing insights into the development of new therapeutic strategies against muscle atrophy. Abbreviations : DEAF1: Deformed epidermal autoregulatory factor-1; FOXO: Forkhead box O; MuSC: Muscle Stem Cell; PAX7: Paired box 7; PIK3C3: Phosphatidylinositol 3-kinase catalytic subunit type 3.

Neurodegenerative disorders are typically featured by the occurrence of neuronal inclusions. In the case of Parkinson's disease (PD) these correspond to Lewy bodies (LBs), which are routinely defined as proteinaceous inclusions composed of alpha-synuclein (alpha-syn). In turn, alpha-syn is considered to be the key protein in producing PD and fostering its progression. Recent studies challenged such a concept and emphasized the occurrence of other proteins such as p62 and poly-ubiquitin (Poly-ub) in the composition of LBs, which are also composed of large amounts of tubulo-vesicular structures. All these components, which accumulate within the cytosol of affected neurons in PD, may be the consequence of a dysfunction of major clearing pathways. In fact, autophagy-related systems are constantly impaired in inherited PD and genetic models of PD. The present study was designed to validate whether a pharmacological inhibition of autophagy within catecholamine cells produces cell damage and accumulation of specific proteins and tubulo-vesicular structures. The stoichiometry counts of single proteins, which accumulate within catecholamine neurons was carried out along with the area of tubulo-vesicular structures. In these experimental conditions p62 and Poly-ub accumulation exceeded at large the amounts of alpha-syn. In those areas where Poly-ub and p62 were highly expressed, tubulo-vesicular structures were highly represented compared with surrounding cytosol. The present study confirms new vistas about LBs composition and lends substance to the scenario that autophagy inhibition rather than a single protein dysfunction as key determinant of PD., Competing Interests: Declarations. Conflict of interest: The authors have no competing interests to declare that are relevant to the content of this article., (© 2024. The Author(s).)

Spinal cord injury (SCI) often leads to neurological dysfunction, and neuronal cell death is one of the main causes of neurological dysfunction. After SCI, in addition to necrosis, programmed cell death (PCD) occurs in nerve cells. At first, studies recognized only necrosis, apoptosis, and autophagy. In recent years, researchers have identified new forms of PCD, including pyroptosis, necroptosis, ferroptosis, and cuproptosis. Related studies have confirmed that all of these cell death modes are involved in various phases of SCI and affect the direction of the disease through different mechanisms and pathways. Furthermore, regulating neuronal cell death after SCI through various means has been proven to be beneficial for the recovery of neural function. In recent years, emerging therapies for SCI have also provided new potential methods to restore neural function. Thus, the relationship between SCI and cell death plays an important role in the occurrence and development of SCI. This review summarizes and generalizes the relevant research results on neuronal necrosis, apoptosis, autophagy, pyroptosis, necroptosis, ferroptosis, and cuproptosis after SCI to provide a new understanding of neuronal cell death after SCI and to aid in the treatment of SCI., Competing Interests: Declarations. Ethics Approval and Consent to Participate: Not applicable. Consent to Participate: Not applicable. Consent for Publication: Not applicable. Conflicts of Interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Reticulophagy, which directs the endoplasmic reticulum (ER) to the phagophore for sequestration within an autophagosome and subsequent lysosomal degradation via specific receptors, is essential for ER quality control and is implicated in various diseases. This study utilizes Drosophila to establish an in vivo model for reticulophagy. Starvation-induced reticulophagy is detected across multiple tissues in Drosophila . Whole-body upregulation or downregulation of the expression of reticulophagy receptors, atl and Rtnl1 , negatively affects fly health. Notably, moderate upregulation of reticulophagy in neuronal tissues by overexpressing these receptors reduces age-related degeneration. In a Drosophila Alzheimer model expressing human APP (amyloid beta precursor protein), reticulophagy is compromised. Correcting reticulophagy by enhancing atl and Rtnl1 expression in the neurons promotes APP degradation, significantly reducing neurodegenerative symptoms. However, overexpression of mutated atl and Rtnl1 , which disrupts the interaction of the corresponding proteins with Atg8, does not alleviate these symptoms, emphasizing the importance of receptor functionality. These findings support modulating reticulophagy as a therapeutic strategy for aging and neurodegenerative diseases associated with ER protein accumulation.

Selective macroautophagy/autophagy in metazoans involves the conserved receptors NBR1 and SQSTM1/p62. Both autophagy receptors manage ubiquitinated cargo recognition, while SQSTM1 has an additional, distinct role of facilitating liquid-liquid phase separation (LLPS) during autophagy. Given that plants lack SQSTM1, it is postulated that plant NBR1 may combine activities of both metazoan NBR1 and SQSTM1. However, the precise mechanism by which plant NBR1 recognizes non-ubiquitinated substrates and its ability to undergo LLPS during selective autophagy remain elusive. Here, we implicate both the ZZ-type zinc finger motif and the four-tryptophan domain of Arabidopsis NBR1 (AtNBR1) in the recognition of non-ubiquitinated cargo proteins. Additionally, we reveal that AtNBR1 indeed undergoes LLPS prior to ATG8-mediated autophagosome formation, crucial for heat stress resistance in Arabidopsis. Our findings unveil the dual roles of AtNBR1 in both cargo recognition and LLPS during plant autophagy and advance our understanding of NBR1-mediated autophagy in plants compared to metazoans. Abbreviations : ATG8: autophagy 8; Co-IP: co-immunoprecipitation; EXO70E2: exocyst subunit EXO70 family protein E2; FRAP: fluorescence recovery after photobleaching; FW domain: four-tryptophan domain; GFP: green fluorescent protein; HS: heat stress; LLPS: liquid-liquid phase separation; LIR: LC3-interacting region; NBR1: next to BRCA1 gene 1; PAS: phagophore assembly site; PB1 domain: Phox and Bem1 domain; RFP: red fluorescent protein; ROF1: rotamase FKBP 1; SARs: selective autophagy receptors; UBA domain: ubiquitin-associated domain; Y2H: yeast two-hybrid; ZZ domain: ZZ-type zinc finger motif domain.

Objective: The superficial zone cells in articular cartilage (SFZCs) have been identified as stem/progenitor chondrocytes and promoted cell self-renewal in the osteoarthritis (OA). Several studies emphasized the involvement of senescence and autophagy in OA. Interleukin-1β (IL-1β) is one of the main inflammatory mediators of OA, and whether it induces senescence and autophagy in SFZCs remains unclear. The present study aimed to investigate autophagy flux, mitochondrial function, and intracellular reactive oxygen species (ROS) that resulted in senescence in SFZCs induced by IL-1β., Methods: Using western blotting, reverse transcription-quantitative PCR, immunofluorescence, intracellular ROS detection, mitochondrial staining, and determination of mitochondrial membrane potential, we tested senescence and autophagy markers in SFZCs induced by IL-1β in vitro . The consequences of mitochondrial function and ROS were also studied with IL-1β-induced senescence., Results: IL-1β treatment decreased SFZC proliferation, induced SFZC senescence, and reduced SFZCs' chondrogenic differentiation capacity. Moreover, IL-1β impaired autophagy flux, and the autophagy activator, rapamycin, attenuated the senescence of SFZCs. IL-1β-induced autophagy defect resulted in mitochondrial dysfunction and overproduction of ROS, and autophagy activation notably protected against mitochondrial dysfunction and reduced the levels of ROS. Moreover, antioxidant N-acetylcysteine reversed the senescence of IL-1β in SFZCs., Conclusion: IL-1β promotes autophagy impairment and subsequently results in dysfunctional mitochondria and overproduction of ROS, which finally causes SFZC senescence., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Autophagy is an intracellular recycling process that maintains cellular homeostasis by degrading excess or defective macromolecules and organelles. Chaperone-mediated autophagy (CMA) is a highly selective form of autophagy in which a substrate containing a KFERQ-like motif is recognized by a chaperone protein, delivered to the lysosomal membrane, and then translocated to the lysosome for degradation with the assistance of lysosomal membrane protein 2A. Normal CMA activity is involved in the regulation of cellular proteostasis, metabolism, differentiation, and survival. CMA dysfunction disturbs cellular homeostasis and directly participates in the pathogenesis of human diseases. Previous investigations on CMA in the central nervous system have primarily focus on neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. Recently, mounting evidence suggested that brain injuries involve a wider range of types and severities, making the involvement of CMA in the bidirectional processes of damage and repair even more crucial. In this review, we summarize the basic processes of CMA and its associated regulatory mechanisms and highlight the critical role of CMA in brain injury such as cerebral ischemia, traumatic brain injury, and other specific brain injuries. We also discuss the potential of CMA as a therapeutic target to treat brain injury and provide valuable insights into clinical strategies., Competing Interests: Declarations. Ethics Approval: Not applicable. Consent to Participate: Not applicable. Consent for Publication: Not applicable. Competing Interests: Tha authors declare no competing interests. Research Involving Human Participants and/or Animals: Not applicable., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Aging is a gradual and irreversible physiological process that significantly increases the risks of developing a variety of pathologies, including neurodegenerative, cardiovascular, metabolic, musculoskeletal, and immune system diseases. Mitochondria are the energy-producing organelles, and their proper functioning is crucial for overall cellular health. Over time, mitochondrial function declines causing an increased release of harmful reactive oxygen species (ROS) and DNA, which leads to oxidative stress, inflammation and cellular damage, common features associated with various age-related pathologies. The impairment of mitophagy, the selective removal of damaged or dysfunctional mitochondria by autophagy, is relevant to the development and progression of age-related diseases. The molecular mechanisms that regulates mitophagy levels in aging remain largely uncharacterized. AMBRA1 is an intrinsically disordered scaffold protein with a unique property of regulating the activity of both proliferation and autophagy core machineries. While the role of AMBRA1 during embryonic development and neoplastic transformation has been extensively investigated, its functions in post-mitotic cells of adult tissues have been limited due to the embryonic lethality caused by AMBRA1 deficiency. Recently, a key role of AMBRA1 in selectively regulating mitophagy in post-mitotic cells has emerged. Here we summarize and discuss these results with the aim of providing a comprehensive view of the mitochondrial roles of AMBRA1, and how defective activity of AMBRA1 has been functionally linked to mitophagy alterations observed in age-related degenerative disorders, including muscular dystrophy/sarcopenia, Parkinson diseases, Alzheimer diseases and age-related macular degeneration. Abbreviations: AD: Alzheimer disease; AMD: age-related macular degeneration; AMBRA1: autophagy and beclin 1 regulator 1; APOE4: apolipoprotein E4; ATAD3A: ATPase family AAA domain containing 3A; ATG: autophagy related; BCL2: BCL2 apoptosis regulator; BH3: BCL2-homology-3; BNIP3L/NIX: BCL2 interacting protein 3 like; CDK: cyclin dependent kinase; CHUK/IKKα: component of inhibitor of nuclear factor kappa B kinase complex; CRL2: CUL2-RING ubiquitin ligase; DDB1: damage specific DNA binding protein 1; ER: endoplasmic reticulum; FOXO: forkhead box O; FUNDC1: FUN14 domain containing 1; GBA/β-glucocerebrosidase: glucosylceramidase beta; HUWE1: HECT, UBA and WWE domain containing E3 ubiquitin protein ligase 1; IDR: intrinsically disordered region; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAVS: mitochondrial antiviral signaling protein; MCL1: MCL1 apoptosis regulator, BCL2 family member; MFN2: mitofusin 2; MTOR: mechanistic target of rapamycin kinase; MSA: multiple system atrophy; MYC: MYC proto-oncogene, bHLH transcription factor; NUMA1: nuclear mitotic apparatus protein 1; OMM; mitochondria outer membrane; PD: Parkinson disease; PHB2: prohibitin 2; PINK1: PTEN induced kinase 1; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PTK2/FAK: protein tyrosine kinase 2; ROS: reactive oxygen species; RPE: retinal pigment epithelium; SAD: sporadic AD; SOCS3: suppressor of cytokine signaling 3; SRC, SRC proto-oncogene, non-receptor tyrosine kinase; STAT3: signal transducer and activator of transcription 3; STING1: stimulator of interferon response cGAMP interactor 1; SQSTM1/p62: sequestosome 1; TBK1: TANK binding kinase 1; TGFB/TGFβ: transforming growth factor beta; TOMM: translocase of outer mitochondrial membrane; TRAF6: TNF receptor associated factor 6; TRIM32: tripartite motif containing 32; ULK1: unc-51 like autophagy activating kinase 1.

Alpha-synuclein (α-Syn) is a specific neuronal protein that regulates neurotransmitter release and trafficking of synaptic vesicles. Exosome-associated α-Syn which is specific to the central nervous system (CNS) is involved in the pathogenesis of epilepsy. Therefore, this review aimed to elucidate the possible link between α-Syn and epilepsy, and how it affects the pathophysiology of epilepsy. A neurodegenerative protein such as α-Syn is implicated in the pathogenesis of epilepsy. Evidence from preclinical and clinical studies revealed that upregulation of α-Syn induces progressive neuronal dysfunctions through induction of oxidative stress, neuroinflammation, and inhibition of autophagy in a vicious cycle with subsequent development of severe epilepsy. In addition, accumulation of α-Syn in epilepsy could be secondary to the different cellular alterations including oxidative stress, neuroinflammation, reduction of brain-derived neurotrophic factor (BDNF) and progranulin (PGN), and failure of the autophagy pathway. However, the mechanism of α-Syn-induced-epileptogenesis is not well elucidated. Therefore, α-Syn could be a secondary consequence of epilepsy. Preclinical and clinical studies are warranted to confirm this causal relationship., Competing Interests: Declarations. Ethics Approval and Consent to Participate: Not applicable. Consent for Publication: Not applicable. Conflict of Interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Keloids are a severe form of scarring for which the underlying mechanisms are poorly understood, and treatment options are limited or inconsistent. Although biomechanical forces are potential drivers of keloid scarring, the direct cellular responses to mechanical cues have yet to be defined. The aim of this study was to examine the distinct responses of normal dermal fibroblasts and keloid-derived fibroblasts (KDFs) to changes in extracellular matrix stiffness. When cultured on hydrogels mimicking the elasticity of normal or scarred skin, KDFs displayed greater stiffness-dependent increases in cell spreading, F-actin stress fiber formation, and focal adhesion assembly. Elevated actomyosin contractility in KDFs disrupted the normal mechanical regulation of extracellular matrix deposition and conferred resistance on myosin inhibitors. Transcriptional profiling identified mechanically regulated pathways in normal dermal fibroblasts and KDFs, including the actin cytoskeleton, Hippo signaling, and autophagy. Further analysis of the autophagy pathway revealed that autophagic flux was intact in both fibroblast populations and depended on actomyosin contractility. However, KDFs displayed marked changes in lysosome organization and an increase in lysosomal exocytosis, which was mediated by actomyosin contractility. Together, these findings demonstrate that KDFs possess an intrinsic increase in cytoskeletal tension, which heightens the response to extracellular matrix mechanics and promotes lysosomal exocytosis., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Porcine reproductive and respiratory syndrome virus (PRRSV) is a major swine pathogen, which can survive host antiviral immunity with various mechanisms. PRRSV infection induces macroautophagy/autophagy, facilitating virus replication. MALT1, a central immune regulator, was manipulated by PRRSV to optimize viral infection at different stages of the virus cycle. In this study, the key role of MALT1 in autophagy regulation during PRRSV infection was characterized, enlightening the role of autophagy flux in favor of virus spread and persistent infection. PRRSV-induced autophagy was confirmed to facilitate virus proliferation. Furthermore, autophagic fusion was dynamically regulated during PRRSV infection. Importantly, PRRSV-induced MALT1 facilitated autophagosome-lysosome fusion and autolysosome formation, thus contributing to autophagy flux and virus proliferation. Mechanically, MALT1 regulated autophagy via mediating MTOR-ULK1 and -TFEB signaling and affecting lysosomal homeostasis. MALT1 inhibition by inhibitor Mi-2 or RNAi induced lysosomal membrane permeabilization (LMP), leading to the block of autophagic fusion. Further, MALT1 overexpression alleviated PRRSV-induced LMP via inhibiting ROS generation. In addition, blocking autophagy flux suppressed virus release significantly, indicating that MALT1-maintained complete autophagy flux during PRRSV infection favors successful virus spread and its proliferation. In contrast, autophagosome accumulation upon MALT1 inhibition promoted PRRSV reserve for future virus proliferation once the autophagy flux recovers. Taken together, for the first time, these findings elucidate that MALT1 was utilized by PRRSV to regulate host autophagy flux, to determine the fate of virus for either proliferation or reserve. Abbreviations : 3-MA: 3-methyladenine; BafA1: bafilomycin A 1 ; BFP/mBFP: monomeric blue fluorescent protein; CQ: chloroquine; DMSO: dimethyl sulfoxide; dsRNA: double-stranded RNA; GFP: green fluorescent protein; hpi: hours post infection; IFA: indirect immunofluorescence assay; LAMP1: lysosomal associated membrane protein 1; LGALS3: galectin 3; LLOMe: L-leucyl-L-leucine-methyl ester; LMP: lysosomal membrane permeabilization; mAb: monoclonal antibody; MALT1: MALT1 paracaspase; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; NFKB/NF-κB: nuclear factor kappa B; nsp: nonstructural protein; ORF: open reading frame; pAb: polyclonal antibody; PRRSV: porcine reproductive and respiratory syndrome virus; PRRSV-N: PRRSV nucleocapsid protein; Rapa: rapamycin; RFP: red fluorescent protein; ROS: reactive oxygen species; SBI: SBI-0206965; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; TCID 50 : 50% tissue culture infective dose; TFEB: transcription factor EB; ULK1: unc-51 like autophagy activating kinase 1.

Sepsis, a life-threatening condition resulting from a dysregulated response to pathogen infection, poses a significant challenge in clinical management. Here, we report a novel role for the autophagy receptor NCOA4 in the pathogenesis of sepsis. Activated macrophages and monocytes secrete NCOA4, which acts as a mediator of septic death in mice. Mechanistically, lipopolysaccharide, a major component of the outer membrane of Gram-negative bacteria, induces NCOA4 secretion through autophagy-dependent lysosomal exocytosis mediated by ATG5 and MCOLN1. Moreover, bacterial infection with E. coli or S. enterica leads to passive release of NCOA4 during GSDMD-mediated pyroptosis. Upon release, extracellular NCOA4 triggers the activation of the proinflammatory transcription factor NFKB/NF-κB by promoting the degradation of NFKBIA/IκB molecules. This process is dependent on the pattern recognition receptor AGER, rather than TLR4. In vivo studies employing endotoxemia and polymicrobial sepsis mouse models reveal that a monoclonal neutralizing antibody targeting NCOA4 or AGER delays animal death, protects against organ damage, and attenuates systemic inflammation. Furthermore, elevated plasma NCOA4 levels in septic patients, particularly in non-survivors, correlate positively with the sequential organ failure assessment score and concentrations of lactate and proinflammatory mediators, such as TNF, IL1B, IL6, and HMGB1. These findings demonstrate a previously unrecognized role of extracellular NCOA4 in inflammation, suggesting it as a potential therapeutic target for severe infectious diseases. Abbreviation: BMDMs: bone marrow-derived macrophages; BUN: blood urea nitrogen; CLP: cecal ligation and puncture; ELISA: enzyme-linked immunosorbent assay; LPS: lipopolysaccharide; NO: nitric oxide; SOFA: sequential organ failure assessment.

Macroautophagy/autophagy is a fundamental cellular catabolic process that delivers cytoplasmic components into double-membrane vesicles called autophagosomes, which then fuse with lysosomes and their contents are degraded. Autophagy recycles cytoplasmic components, including misfolded proteins, dysfunctional organelles and even microbial invaders, thereby playing an essential role in development, immunity and cell death. Autophagosome formation is the main step in autophagy, which is governed by a set of ATG (autophagy related) proteins. ATG16L1 interacts with ATG12-ATG5 conjugate to form an ATG12-ATG5-ATG16L1 complex. The complex acts as a ubiquitin-like E3 ligase that catalyzes the lipidation of MAP1LC3/LC3 (microtubule associated protein 1 light chain 3), which is crucial for autophagosome formation. In the present study, we found that ATG16L1 was subject to S -palmitoylation on cysteine 153, which was catalyzed by ZDHHC7 (zinc finger DHHC-type palmitoyltransferase 7). We observed that re-expressing ATG16L1 but not the S -palmitoylation-deficient mutant ATG16L1 C153S rescued a defect in the lipidation of LC3 and the formation of autophagosomes in ATG16L1 -KO (knockout) HeLa cells. Furthermore, increasing ATG16L1 S -palmitoylation by ZDHHC7 expression promoted the production of LC3-II, whereas reducing ATG16L1 S -palmitoylation by ZDHHC7 deletion inhibited the LC3 lipidation process and autophagosome formation. Mechanistically, the addition of a hydrophobic 16-carbon palmitoyl group on Cys153 residue of ATG16L1 enhances the formation of ATG16L1-WIPI2B complex and ATG16L1-RAB33B complex on phagophore, thereby facilitating the LC3 lipidation process and autophagosome formation. In conclusion, S -palmitoylation of ATG16L1 is essential for the lipidation process of LC3 and the formation of autophagosomes. Our research uncovers a new regulatory mechanism of ATG16L1 function in autophagy. Abbreviation : ABE: acyl-biotin exchange; ATG: autophagy related; Baf-A1: bafilomycin A 1 ; 2-BP: 2-bromopalmitate; CCD: coiled-coil domain; co-IP: co-immunoprecipitation; CQ: chloroquine; EBSS: Earle's balanced salt solution; HAM: hydroxylamine; KO: knockout; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; NP-40: Nonidet P-40; PBS: phosphate-buffered saline; PE: phosphatidylethanolamine; PtdIns3K-C1: class III phosphatidylinositol 3-kinase complex I; PTM: post-translational modification; RAB33B: RAB33B, member RAS oncogene family; RB1CC1/FIP200: RB1 inducible coiled-coil 1; SDS: sodium dodecyl sulfate; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscope; WD: tryptophan and aspartic acid; WIPI2B: WD repeat domain, phosphoinositide interacting 2B; WT: wild-type; ZDHHC: zinc finger DHHC-type palmitoyltransferase.

Loss of ovarian homeostasis is associated with ovary dysfunction and female diseases; however, the underlying mechanisms responsible for the establishment of homeostasis and its function in the ovary have not been fully elucidated. Here, we showed that conditional knockout of Rab37 in oocytes impaired macroautophagy/autophagy proficiency in the ovary and interfered with follicular homeostasis and ovary development in mice. Flunarizine treatment upregulated autophagy, thus rescuing the impairment of follicular homeostasis and ovarian dysfunction in rab37 knockout mice by reprogramming of homeostasis. Notably, both the E2F1 and EGR2 transcription factors synergistically activated Rab37 transcription and promoted autophagy. Thus, RAB37-mediated autophagy ensures ovary function by maintaining ovarian homeostasis. Abbreviations: AMH: anti-Mullerian hormone; ATG: autophagy related; BECN1: beclin 1; cKO: conditional knockout; Cre: cyclization recombination enzyme; dpp: days postpartum; E2: estradiol; E2F1: E2F transcription factor 1; EBF1: EBF transcription factor 1; EGR2: early growth response 2; FSH: follicle stimulating hormone; LH: luteinizing hormone; mpp: months postpartum; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; RAB37: RAB37, member RAS oncogene family; SQSTM1: sequestosome 1; TFEB: transcription factor EB; Zp3 : zona pellucida glycoprotein 3.

The Zika virus (ZIKV) outbreaks and its co-relation with microcephaly have become a global health concern. It is primarily transmitted by a mosquito, but can also be transmitted from an infected mother to her fetus causing impairment in brain development, leading to microcephaly. However, the underlying molecular mechanism of ZIKV-induced microcephaly is poorly understood. In this study, we explored the role of ZIKV non-structural protein NS4A and NS4B in ZIKV pathogenesis in a well-characterized primary culture of human fetal neural stem cells (fNSCs). We observed that the co-transfection of NS4A and NS4B altered the neural stem cell fate by arresting proliferation and inducing premature neurogenesis. NS4A + NS4B transfection in fNSCs increased autophagy and dysregulated notch signaling. Further, it also altered the regulation of downstream genes controlling cell proliferation. Additionally, we reported that 3 methyl-adenine (3-MA), a potent autophagy inhibitor, attenuated the deleterious effects of NS4A and NS4B as evidenced by the rescue in Notch1 expression, enhanced proliferation, and reduced premature neurogenesis. Our attempts to understand the mechanism of autophagy induction indicate the involvement of mitochondrial fission and ROS. Collectively, our findings highlight the novel role of NS4A and NS4B in mediating NSC fate alteration through autophagy-mediated notch degradation. The study also helps to advance our understanding of ZIKV-induced neuropathogenesis and suggests autophagy as a potential target for anti-ZIKV therapeutic intervention., Competing Interests: Declarations. Ethical Approval: Strict guidelines of institutional Human ethics and stem cell research committee of NBRC, India in compliance with recommendations of the Indian Council of Medical Research (ICMR) and Department of Biotechnology (DBT), India were followed for isolation of Neural stem cells from aborted human fetus. Consent to Participate: Not applicable. Consent to Publish: Not applicable. Competing Interest: The authors declare no competing interests., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Spautin-1 is a well-known macroautophagy/autophagy inhibitor via suppressing the deubiquitinases USP10 and USP13 and promoting the degradation of the PIK3C3/VPS34-BECN1 complex, while its effect on selective autophagy remains poorly understood. Mitophagy is a selective form of autophagy for removal of damaged and superfluous mitochondria via the autophagy-lysosome pathway. Here, we report a surprising discovery that, while spautin-1 remains as an effective autophagy inhibitor, it promotes PINK1-PRKN-dependent mitophagy induced by mitochondrial damage agents. Mechanistically, spautin-1 facilitates the stabilization and activation of the full-length PINK1 at the outer mitochondrial membrane (OMM) via binding to components of the TOMM complex (TOMM70 and TOMM20), leading to the disruption of the mitochondrial import of PINK1 and prevention of PARL-mediated PINK1 cleavage. Moreover, spautin-1 induces neuronal mitophagy in Caenorhabditis elegans ( C. elegans ) in a PINK-1-PDR-1-dependent manner. Functionally, spautin-1 is capable of improving associative learning capability in an Alzheimer disease (AD) C. elegans model. In summary, we report a novel function of spautin-1 in promoting mitophagy via the PINK1-PRKN pathway. As deficiency of mitophagy is closely implicated in the pathogenesis of neurodegenerative disorders, the pro-mitophagy function of spautin-1 might suggest its therapeutic potential in neurodegenerative disorders such as AD. Abbreviations: AD, Alzheimer disease; ATG, autophagy related; BafA1, bafilomycin A 1 ; CALCOCO2/NDP52, calcium binding and coiled-coil domain 2; CCCP, carbonyl cyanide m-chlorophenyl hydrazone; COX4/COX IV, cytochrome c oxidase subunit 4; EBSS, Earle's balanced salt; ECAR, extracellular acidification rate; GFP, green fluorescent protein; IA, isoamyl alcohol; IMM, inner mitochondrial membrane; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MMP, mitochondrial membrane potential; mtDNA, mitochondrial DNA; nDNA, nuclear DNA; O/A, oligomycin-antimycin; OCR, oxygen consumption rate; OMM, outer mitochondrial membrane; OPTN, optineurin; PARL, presenilin associated rhomboid like; PINK1, PTEN induced kinase 1; PRKN, parkin RBR E3 ubiquitin protein ligase; p-Ser65-Ub, phosphorylation of Ub at Ser65; TIMM23, translocase of inner mitochondrial membrane 23; TOMM, translocase of outer mitochondrial membrane; USP10, ubiquitin specific peptidase 10; USP13, ubiquitin specific peptidase 13; VAL, valinomycin; YFP, yellow fluorescent protein.

Cerebral ischemia-reperfusion (I/R) injury is a complex pathophysiological process involving multiple mechanisms, including apoptosis and autophagy, which can lead to significant neuronal damage. PIEZO1, a stretch-activated ion channel, has recently emerged as a potential regulator of cellular responses to ischemic conditions. However, its role in neuronal cell survival and death during ischemic events is not well elucidated. This study aimed to ascertain the regulatory function of PIEZO1 in neuronal cell apoptosis and autophagy in an in vitro model of hypoxia-reoxygenation and an in vivo model of brain I/R injury. HT22 hippocampal neuronal cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to simulate ischemic conditions, with subsequent reoxygenation. In vitro, PIEZO1 expression was silenced using small interfering RNA (si-RNA) transfection. The effects on cell viability, apoptosis, and autophagy were assessed using CCK-8 assays, PI-Annexin/V staining combined with flow cytometry, and Western blot analysis. Additionally, intracellular Ca 2+ levels in HT22 cells were measured using a Ca 2+ probe. The involvement of the AMPK-mTOR pathway was investigated using rapamycin. For in vivo validation, middle cerebral artery occlusion/reperfusion (MCAO/R) in rats was employed. To determine the neuroprotective role of PIEZO1 silencing, sh-PIEZO1 adeno-associated virus was stereotaxically injected into the cerebral ventricle, and neurological and histological outcomes were assessed using neurological scoring, TTC staining, H&E staining, Nissl staining, and immunofluorescence. In HT22 cells, OGD/R injury notably upregulated PIEZO1 expression and intracellular Ca 2+ levels. Silencing PIEZO1 significantly diminished OGD/R-induced Ca 2+ influx, apoptosis, and autophagy, as indicated by lower levels of pro-apoptotic and autophagy-related proteins and improved cell viability. Additionally, PIEZO1 modulated the AMPK-mTOR signaling pathway, an effect that was counteracted by rapamycin treatment, implying its regulatory role. In vivo, PIEZO1 silencing ameliorated brain I/R injury in MCAO/R rats, demonstrated by improved neurological function scores and reduced neuronal apoptosis and autophagy. However, these neuroprotective effects were reversed through rapamycin treatment. Our findings indicate that PIEZO1 is upregulated following ischemic injury and facilitates Ca 2+ influx, apoptosis, and autophagy via the AMPK-mTOR pathway. Silencing PIEZO1 confers neuroprotection against I/R injury both in vitro and in vivo, highlighting its potential as a therapeutic target for stroke management., Competing Interests: Declarations. Competing Interests: The authors declare no competing interests. Ethical Approval and Consent to Participate: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was approved by Institutional Review Board of Dongying People’s Hospital (DYRMYY-023)., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Autophagy, a crucial mechanism for cellular degradation, is regulated by conserved autophagy-related (ATG) core proteins across species. Impairments in autophagy result in significant developmental and reproductive aberrations in mammals. However, autophagy is thought to be functionally dispensable in Arabidopsis thaliana since most of the ATG mutants lack severe growth and reproductive defects. Here, we challenge this perception by unveiling a role for autophagy in male gametophyte development and fertility in Arabidopsis. A detailed re-assessment of atg5 and atg7 mutants found that reduced autophagy activity in germinated pollen accompanied by partial aberrations in sperm cell biogenesis and pollen tube growth, leading to compromised seed formation. Furthermore, we revealed autophagy modulates the spatial organization of actin filaments via targeted degradation of actin depolymerization factors ADF7 and Profilin2 in pollen grains and tubes through a key receptor, Neighbor of BRCA1 (NBR1). Our findings advance the understanding of the evolutionary conservation and diversification of autophagy in modulating male fertility in plants contrasting to mammals., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Autophagy is a highly conserved 'self-digesting' mechanism used in eukaryotes to degrade and recycle cellular components by enclosing them in a double membrane compartment and delivering them to lytic organelles (lysosomes or vacuoles). Extensive studies in plants have revealed how autophagy is intricately linked to essential aspects of metabolism and growth, in both normal and stress conditions, including cellular and organelle homeostasis, nutrient recycling, development, responses to biotic and abiotic stresses, senescence and cell death. However, knowledge regarding autophagic processes in other photosynthetic organisms remains limited. In this review, we attempt to summarize the current understanding of autophagy in algae from a metabolic, molecular and evolutionary perspective. We focus on the composition and conservation of the autophagy molecular machinery in eukaryotes and discuss the role of autophagy in metabolic regulation, cellular homeostasis and stress adaptation in algae. This article is part of the theme issue 'The evolution of plant metabolism'.

Metabolic homeostasis and the ability to link energy supply to demand are essential requirements for all living cells to grow and proliferate. Key to metabolic homeostasis in all eukaryotes are AMPK and mTORC1, two kinases that sense nutrient levels and function as counteracting regulators of catabolism (AMPK) and anabolism (mTORC1) to control cell survival, growth and proliferation. Discoveries beginning in the early 2000s revealed that AMPK and mTORC1 communicate, or cross-talk, through direct and indirect phosphorylation events to regulate the activities of each other and their shared protein substrate ULK1, the master initiator of autophagy, thereby allowing cellular metabolism to rapidly adapt to energy and nutritional state. More recent reports describe divergent mechanisms of AMPK/mTORC1 cross-talk and the elaborate means by which AMPK and mTORC1 are activated at the lysosome. Here, we provide a comprehensive overview of current understanding in this exciting area and comment on new evidence showing mTORC1 feedback extends to the level of the AMPK isoform, which is particularly pertinent for some cancers where specific AMPK isoforms are implicated in disease pathogenesis., (© 2024 The Author(s).)

Amyotrophic lateral sclerosis (ALS) is a debilitating and fatal paralytic disorder associated with motor neuron death. Mutant superoxide dismutase 1 (SOD1) misfolding and aggregation have been linked to familial ALS, with the accumulation of abnormal wild-type SOD1 species being also observed in postmortem tissue of sporadic ALS cases. Both wild-type and mutated SOD1 are reported to contribute to motoneuron cell death. The autophagic pathway has been shown to be dysregulated in ALS. Recent evidence suggests a dual time-dependent role of autophagy in the progression of the disease. PACER, also called RUBCNL (Rubicon-like), is an enhancer of autophagy and has been found diminished in its levels during ALS pathology in mice and humans. Pacer loss of function disturbs the autophagy process and leads to the accumulation of SOD1 aggregates, as well as sensitizes neurons to death. Therefore, here we investigated if constitutive overexpression of PACER in neurons since early development is beneficial in an in vivo model of ALS. We generated a transgenic mouse model overexpressing human PACER in neurons, which then was crossbred with the mutant SOD1 G93A ALS mouse model. Unexpectedly, PACER/SOD1 G93A double transgenic mice exhibited an earlier disease onset and shorter lifespan than did littermate SOD1 G93A mice. The overexpression of PACER in neurons in vivo and in vitro increased the accumulation of SOD1 aggregates, possibly due to impaired autophagy. These results suggest that similar to Pacer loss-of function, Pacer gain-of function is detrimental to autophagy, increases SOD1 aggregation and worsens ALS pathogenesis. In a wider context, our results indicate the requirement to maintain a fine balance of PACER protein levels to sustain proteostasis., Competing Interests: Declarations Ethics approval and consent to participate All animal procedures described in this study were approved by the Animal Welfare and Ethics Committee of Universidad Mayor (Protocol No. 9/2015 and Protocol No. 2/2020). Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests., (© 2024. The Author(s).)

Mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth and its dysregulation leads to a variety of human diseases. Although NPRL2, an essential component of the GATOR1 complex, is reported to effectively suppress amino acid-induced mTORC1 activation, the regulation of NPRL2 protein stability is unclear. In this study, we show that chaperon-associated ubiquitin ligase CHIP interacts with NPRL2 and promotes its polyubiquitination and proteasomal degradation. Moreover, HSP70 mediates CHIP-induced ubiquitination and degradation of NPRL2. Consistently, overexpression of HSP70 enhances whereas HSP70 depletion inhibits amino acid-induced mTORC1 activation. Accordingly, knockdown of HSP70 promotes basal autophagic flux, and inhibits cell growth and proliferation. Taken together, these results demonstrated that HSP70 is a novel activator of mTORC1 through mediating CHIP-induced ubiquitination and degradation of NPRL2., (© 2024 Federation of American Societies for Experimental Biology.)

Parkinson's disease (PD), a neurodegenerative disorder characterized by impaired motor function, is typically treated with medications and surgery. However, recent studies have validated physical exercise as an effective adjunct therapy, significantly improving both motor and non-motor symptoms in PD patients. Irisin, a myokine, has garnered increasing attention for its beneficial effects on the nervous system. Research has shown that irisin plays a crucial role in regulating metabolic balance, optimizing autophagy, maintaining mitochondrial quality, alleviating oxidative stress and neuroinflammation, and regulating cell death-all processes intricately linked to the pathogenesis of PD. This review examines the mechanisms through which irisin may counteract PD, provides insights into its biological effects, and considers its potential as a target for therapeutic strategies., Competing Interests: Declaration of competing interest There are no financial or personal relationships with any commercial entities or organizations that could be perceived as influencing the study's content, results, interpretation, or conclusions., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Autophagy-dependent ferroptosis and glycolysis play a significant role in tumor development. α-Enolase (ENO1), a glycolytic enzyme, has been demonstrated to function as a crucial modulator in breast cancer (BC). However, the specific mechanism by which ENO1 influences the ferroptosis and glycolysis of BC remains unclear. qRT-PCR, along with western blot analysis was applied to investigate ENO1 and cystatin SN (CST1) expression in BC cells. Glycolysis level was measured by extracellular acidification rate (ECAR), lactate production, glucose consumption, and western blot analysis. Ferroptosis was evaluated by iron and lipid peroxidation assay, DCFH-DA staining, and western blot analysis. Immunofluorescence, together with western blot analysis was adopted for assessing cell autophagy and mTOR signaling pathway. Cell apoptosis and Ki67 level were measured by TUNEL and immunohistochemistry, respectively. ENO1 had abundant existence in BC cell lines. ENO1 silencing inhibited glycolysis but promoted ferroptosis and autophagy. In addition, autophagy inhibitor 3-MA reversed the impacts of ENO1 silencing on glycolysis and ferroptosis. Meanwhile, mTOR activator MHY1485 demonstrated opposing effects on autophagy. Moreover, CST1 could be extensively found in BC cell lines, and its overexpression reversed the effects of ENO1 silencing on glycolysis and ferroptosis. In vivo experiments illustrated that ENO1 deletion suppressed BC tumor growth, increased the apoptosis rate, restrained cell proliferation, and glycolysis, but promoted ferroptosis and autophagy, as well as reducing CST1 and mTOR signaling. To sum up, ENO1 silencing mediated a utophagy-dependent ferroptosis and glycolysis in BC cells by regulating CST1., (© 2024 Wiley Periodicals LLC.)

Acute lung injury (ALI), a multifactorial pathological condition, manifests through heightened inflammatory responses, compromised lung epithelial-endothelial barrier function, and oxidative stress, potentially culminating in respiratory failure and mortality. This study explores the intricate interplay between two crucial cellular mechanisms-extracellular vesicles (EVs) and autophagy-in the context of ALI pathogenesis and potential therapeutic interventions.EVs, bioactive membrane-bound structures secreted by cells, serve as versatile carriers of molecular cargo, facilitating intercellular communication and significantly influencing disease progression. Concurrently, autophagy, an essential intracellular degradation process, maintains cellular homeostasis and has emerged as a promising therapeutic target in ALI and acute respiratory distress syndrome.Our research unveils a fascinating "EV-Autophagy dual-drive pathway," characterized by reciprocal regulation between these two processes. EVs modulate autophagy activation and inhibition, while autophagy influences EV production, creating a dynamic feedback loop. This study posits that precise manipulation of this pathway could revolutionize ALI treatment strategies.By elucidating the mechanisms underlying this cellular crosstalk, we open new avenues for targeted therapies. The potential for engineered EVs to fine-tune autophagy in ALI treatment is explored, alongside innovative concepts such as EV-based vaccines for ALI prevention and management. This research not only deepens our understanding of ALI pathophysiology but also paves the way for novel, more effective therapeutic approaches in critical care medicine., Competing Interests: Declaration of Competing Interest The authors declare that there is no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Chronic pain (CP) affects over 30 % of the global population, imposing significant financial burdens on individuals and society. However, existing treatments for CP offer limited efficacy and troublesome side effects, primarily owing to a lack of knowledge of its precise underlying mechanism. Pathological stimuli disrupt the intricate process of protein folding and endoplasmic reticulum (ER) homeostasis. This disruption leads to the accumulation of misfolded or unfolded proteins in the ER, generating a condition termed ER stress. Emerging data have indicated that ER stress, occurring in the peripheral and central nervous systems, contributes to the development and maintenance of CP. This review aimed to comprehensively explore the intersection of ER stress and CP within the lower and upper nervous systems and highlight the cell-specific contributions of the unfolded protein response in different CP types. We provide a comprehensive synthesis of evidence from animal models, examining neuronal and non-neuronal mechanisms and discuss the damaging ER stress-linked inflammation, autophagy, oxidative stress, and apoptosis, which collectively drive disease progression and contribute to a neurotoxic environment. However, the mechanisms through which ER stress influences the most advanced centre-of-pain projections in the brain remain unclear. Further investigation in this area is crucial to elucidate the relationship between ER stress and CP and facilitate the development of novel therapeutic drugs for this intractable dilemma., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Macroautophagy/autophagy is a conserved pathway allowing the cell to clear and recycle unwanted materials. While decades of research have revealed molecular players and their hierarchical relationships in autophagy, the detailed mechanism by which these molecules function remains largely unknown. In a recent study, Jagan et al. revealed the membrane remodeling ability of two important proteins, MAP1LC3B/LC3B and ATG16L1, in autophagy. LC3B and the ATG12-ATG5-ATG16L1 complex function synergically to induce the formation of phagophore-like membrane cups on membranes both in vitro and in vivo . In addition, the authors showed that the recently characterized C-terminal membrane-binding domain of ATG16L1 is required for the cup formation and the subsequent transition to autophagic vesicles. Together this research provides more insight into the molecular function of LC3B and ATG16L1, as well as a possible mechanism for phagophore biogenesis.

Non-small cell lung cancer (NSCLC) remains the foremost contributor to cancer-related fatalities globally, with limited effective therapeutic modalities. Recent research has shed light on the role of ferroptosis in various types of cancers, offering a potential avenue for improving cancer therapy. Herein, we identified E3 ubiquitin ligase deltex 2 (DTX2) as a potential therapeutic target candidate implicated in promoting NSCLC cell growth by inhibiting ferroptosis. Our investigation revealed a significant upregulation of DTX2 in NSCLC cells and tissues, which was correlated with poor prognosis. Downregulation of DTX2 suppressed NSCLC cell growth both in vitro and in vivo, while its overexpression accelerated cell proliferation. Moreover, knockdown of DTX2 promoted ferroptosis in NSCLC cells, which was mitigated by DTX2 overexpression. Mechanistically, we uncovered that DTX2 binds to nuclear receptor coactivator 4 (NCOA4), facilitating its ubiquitination and degradation via the K48 chain, which subsequently dampens NCOA4-driven ferritinophagy and ferroptosis in NSCLC cells. Notably, DTX2 knockdown promotes cisplatin-induced ferroptosis and overcomes drug resistance of NSCLC cells. These findings underscore the critical role of DTX2 in regulating ferroptosis and NCOA4-mediated ferritinophagy, suggesting its potential as a novel therapeutic target for NSCLC., Competing Interests: Declaration of Competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Autophagy plays an important role in determining stem-cell differentiation. During the osteogenic differentiation of mesenchymal stem cells (MSCs), autophagosome formation is upregulated but the reason is unknown. A long-standing quest in the autophagy field is to find the membrane origin of autophagosomes. In this study, cytoplasmic coat protein complex II (COPII) vesicles, endoplasmic reticulum-derived vesicles responsible for the transport of storage proteins to the Golgi, are demonstrated to be a critical source of osteoblastic autophagosomal membrane. A significant correlation between the number of COPII vesicle and the autophagy level is identified in the rat bone tissues. Disruption of COPII vesicles restrained osteogenesis and decreased the number and size of autophagosomes. SEC31a (an outer coat protein of COPII vesicle) is found to be vital to regulate COPII vesicle-dependent autophagosome formation via interacting with ATG9a of autophagosomal seed vesicles. The interference of Sec31a inhibited autophagosome formation and osteogenesis in vitro and in vivo. These results identified a novel mechanism of autophagosome formation in osteogenic differentiation of stem cells and identified SEC31a as a critical protein that mediates the interplay between COPII and ATG9a vesicles. These findings broaden the understanding of the regulatory mechanism in the osteogenic differentiation of MSCs., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

The regulation of mammalian ovarian development involves the coordinated processes of autophagy and apoptosis. The autophagy-related gene ATG7 plays a pivotal role in mediating crosstalk between these pathways. Despite its recognized importance, the specific function of ATG7 in ovarian follicular granulosa cells remains poorly understood. This study aimed to explore the effects of ATG7 overexpression on apoptosis and autophagy in porcine ovarian follicular granulosa cells and thereby provide insights into the interplay between these fundamental cellular mechanisms. An ATG7 overexpression vector was introduced into cells, followed by assessment of cell proliferation using the CCK-8 assay, quantification of related gene expression via real-time quantitative PCR and western blotting, and evaluation of apoptosis using TUNEL staining. ATG7 exhibited a predominant cytoplasmic localization and additional nuclear expression in porcine ovarian follicular granulosa cells. The transfection efficiency of the vector was initially verified, indicating that its overexpression notably increased expression of ATG7 protein. Further investigations confirmed that overexpression of ATG7 inhibited cell proliferation, stimulated autophagy, and promoted apoptosis in these cells. In summary, overexpression of ATG7 influences the viability of porcine ovarian follicular granulosa cells by regulating the interplay between autophagy and apoptosis. This study not only broadens the understanding of functional regulation of autophagy and apoptosis by ATG7, but also sheds light on the intricate mechanisms governing ovarian follicular atresia., Competing Interests: Declaration of Competing Interest The authors declare that there is no conflict of interest in the manuscript., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Asynchronous nuclear and cytoplasmic maturation in human oocytes is believed to cause morphological anomalies after controlled ovarian hyperstimulation. Vacuolar protein sorting 34 (VPS34) is renowned for its pivotal role in regulating autophagy and endocytic trafficking. To investigate its impact on oocyte development, oocyte-specific knockout mice (ZcKO) are generated, and these mice are completely found infertile, with embryonic development halted at 2- to 4-cell stage. This infertility is related with a disruption on autophagic/mitophagic flux in ZcKO oocytes, leading to subsequent failure of zygotic genome activation (ZGA) in derived 2-cell embryos. The findings further elucidated the regulation of VPS34 on the activity and subcellular translocation of RAS-related GTP-binding protein 7 (RAB7), which is critical not only for the maturation of late endosomes and lysosomes, but also for initiating mitophagy via retrograde trafficking. VPS34 binds directly with RAB7 and facilitates its activity conversion through TBC1 domain family member 5 (TBC1D5). Consistent with the cytoplasmic vacuolation observed in ZcKO oocytes, defects in multiple vesicle trafficking systems are also identified in vacuolated human oocytes. Furthermore, activating VPS34 with corynoxin B (CB) treatment improved oocyte quality in aged mice. Hence, VPS34 activation may represent a novel approach to enhance oocyte quality in human artificial reproduction., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)