Autophagy reports最新文献

Emerging evidence suggests that the propagation of α-synuclein pathology underlies the progression of Parkinson's disease and supports the hypothesis that transmission of α-synuclein aggregates contributes to dopaminergic degeneration. Autophagy, a cellular degradation process, removes protein aggregates and damaged organelles and aids in α-synuclein clearance. However, fibrillar α-synuclein aggregates may evade and even disrupt autophagy, causing toxic spread. The role of autophagy may be multifaceted in the propagation of α-synuclein: clearing α-synuclein aggregates and damaged organelles (protective) versus the release of α-synuclein aggregates (harmful). Here we review how neuronal and glial autophagy regulate α-synuclein clearance and spreading. We also discuss the need for future research to address the interplay of autophagy and α-synuclein aggregates toward therapeutic development.

The systematic dissection of molecular mechanisms through which aerobic exercise (AE) mitigates neurodegenerative pathologies remains a significant challenge. Alzheimer's disease (AD) is characterized by impaired autophagy-lysosomal flux and the accumulation of amyloid-β (Aβ) and hyperphosphorylated tau. We recently identified the β2-adrenergic receptor (β2-AR) as a key mediator of exercise-induced bene = d sought to dissect its role in regulating distinct proteostatic pathways. We revealed that AE activates β2-AR signaling to promote lysosomal acidification via upregulation of VMA21, an essential assembly factor for the vacuolar ATPase (V-ATPase) proton pump, thereby facilitating Aβ clearance. Concurrently, AE enhanced autophagosome-lysosome fusion through the β2-AR - retinoid X receptor alpha (RXRα) - charged multivesicular body protein 4B (CHMP4B) axis, promoting tau degradation. Critically, pharmacological inhibition of β2-AR fully abolished these effects. Here, we propose an integrated mechanism through which β2-AR activation by AE could coordinate dual autophagy-lysosomal recovery processes and suggest that targeting this pathway offers a promising therapeutic strategy for AD and related proteostatic disorders.

The cardiovascular system, consisting of the heart and blood vessels, ensures delivery of oxygen and nutrient-rich blood throughout the whole body. The major cell types include cardiomyocytes, endothelial cells, and vascular smooth muscle cells. Dramatic consequences, sometimes with a deadly outcome, may arise when the activity of cardiovascular cells is compromised. The cardiomyocytes are terminally differentiated cells and thus do not normally regenerate. To sustain the high energy demand of the beating heart, the cardiomyocytes contain a high amount of energy producing mitochondria. Adaptation to metabolic demands is an integral part of cellular homeostasis and involves autophagy. Autophagy is an evolutionary conserved intracellular degradation pathway of cellular constituents. Mitophagy refers to selective degradation of damaged, and thus potentially harmful, mitochondria through autophagy. Both autophagy and mitophagy are widely implicated in physiological and pathological processes within cardiovascular cells. In this review, we highlight studies applying genetic modifications in mouse models to reveal the impact of autophagy and mitophagy on cardiovascular health and disease.

Upon demonstration that basal macroautophagy plays an essential role in maintaining protein homeostasis in the mammalian CNS, there has been excitement around modulating this form of autophagy as a therapeutic strategy to combat neurodegenerative disease. Nonetheless, the initial genetic studies that spawned this excitement did little to reveal the complex physiology of autophagy regulation in neural cells, or the predicament of compartment-specific events upon which these cells rely. Pursuit of therapeutic strategies further highlighted how this intricacy extends across the different organs of the body, raising question as to how we may harness the power of macroautophagy for good while minimizing the bad. Fortunately, since these early studies, the field has made significant gains toward understanding the molecular, cellular and physiological basis of macroautophagy. Together with technological advances, they have refueled the exploration into how this powerful pathway may provide the much-needed therapeutic advances for these yet untreatable diseases. In this review, we will contextualize the insights gained over the last decade with the traditional and novel strategies that have been explored to combat disease-associated events such as abnormal protein accumulation. In addition, we will discuss key considerations and strategies that can influence how a therapeutic approach might be designed.

Autophagy is a highly conserved cellular pathway for the degradation and recycling of defective intracellular cargo and plays a vital role in the homeostasis of post-mitotic tissues, particularly the nervous system. Autophagosome-lysosome fusion represents the final critical step in macroautophagy with a tightly regulated process mediated by a complex molecular machinery of tethering vesicles for degradation. Since the first reports of human autophagy disorders, the scientific and clinical focus condensed on severe phenotypes with biallelic-truncating genotypes as monogenic models of near-complete autophagy perturbation. Recent reports suggest a much wider disease spectrum with defective autophagy, ranging from neurodevelopmental disorders to neurodegenerative phenotypes with later manifestation due to "milder" genotypes, including Alzheimer's disease (AD), Parkinson's disease (PD), and Amyotrophic Lateral Sclerosis-Frontotemporal Dementia (ALS-FTD). In addition, recent evidence identified molecular connections between physiological autophagy regulation during normal aging and pathophysiological hallmarks of aging-related disorders. These translational observations led to a more comprehensive understanding of autophagy at health and disease, in particular: 1) genetic location and allelism of pathogenic variants ("genomic space"); 2) protein-protein interaction in functional protein complexes ("proteomic space"); 3) metabolic autophagic flux with positive and negative regulators ("metabolomic space"); 4) age-related phenotypic progression over time. Here, we review the autophagosome-lysosome fusion machinery as a key structure both on the molecular level and with regards to the pathogenesis of the autophagy-related disease spectrum. We highlight the clinicopathological signature of disorders in the autophagosome-lysosome fusion machinery, in particular features warranting awareness from clinicians and geneticists to inform adequate diagnosis, surveillance, and patient guidance.

Autophagy is a lysosome-directed recycling program that preserves lung homeostasis yet, when dysregulated, can cause disease. This review organizes current evidence by lung compartment and disease phase, proposing that autophagy polarity is determined by cell identity, micro-niche, and timing along the injury-repair continuum. In chronic obstructive pulmonary disease, epithelial autophagy is initially cytoprotective, but chronic smoke exposure reveals a lysosome bottleneck and stalled flux, while alveolar macrophages show impaired xenophagy and poor acidification. In idiopathic pulmonary fibrosis, autophagy is suppressed in type II epithelial cells and fibroblasts downstream of transforming growth factor beta (TGF-β) and mTORC1, which promotes epithelial stress programs and collagen translation. In acute lung injury and respiratory distress syndrome, timely autophagy activation limits cGAS-STING and NLRP3 signaling, preserves barrier integrity, and supports recovery. In asthma, autophagy supports mucin biogenesis in epithelial cells but is reduced in antigen-presenting cells, while eosinophil and mast cell effector functions rely on autophagy. In infection, xenophagy clears microbes but is actively subverted by bacteria and respiratory viruses. In non-small cell lung cancer (NSCLC), tumor-intrinsic autophagy maintains energy metabolism, redox balance, and enables immune evasion, whereas host autophagy can alternately support antitumor immunity or supply nutrients. We summarize small-molecule modulators, delivery strategies, and flux-aware tools that enable precise, cell- and phase-resolved modulation of autophagy to guide patient selection and improve therapy in respiratory disease.

Skeletal muscle is a heterogeneous tissue composed of fibers with distinct contractile, metabolic, and molecular characteristics. This intrinsic heterogeneity influences how individual fibers respond to physiological stimuli, pathological stress, and cellular remodeling processes such as autophagy. Skeletal muscle autophagy is essential for maintaining proteostasis and organelle quality, particularly in high-demand tissues like skeletal muscle. However, emerging evidence indicates that autophagy is not uniformly regulated across all muscles and fibers within a skeletal muscle. Fast/glycolytic fibers, characterized by faster contractile speed and high glycolytic capacity, exhibit greater autophagic flux potentially driven by activation of energy signals, calcium, and redox-sensitive pathways. In contrast, slow/oxidative fibers, characterized by slow contractile speed and higher oxidative metabolism, show lower inducible autophagy despite elevated basal expression of autophagy-related proteins. These differences are compounded by fiber type - specific organelle architecture, recruitment patterns during activity and disuse, and substrate availability and utilization. Further, pathological conditions such as disuse, chronic disease, and myopathies often induce fiber type alterations as well as changes to organelle content and function that are closely associated with changes in autophagy signaling. Additionally, species and strain variability add another layer of complexity, complicating both the interpretation and translational relevance of autophagy studies in skeletal muscle. This review synthesizes current evidence linking skeletal muscle phenotype to autophagy regulation and highlights the need to consider skeletal muscle heterogeneity as a central variable in skeletal muscle autophagy research. A deeper understanding of skeletal muscle type/fiber-specific autophagy will improve our ability to interpret experimental findings and develop targeted interventions for skeletal muscle dysfunction.

Epithelial and endothelial barriers are essential for tissue homeostasis, protecting the body from environmental insults while regulating selective transport. The integrity of these barriers relies on dynamic intercellular junctions whose composition and organization are constantly remodeled in response to stress and physiological cues. Autophagy and endocytic trafficking are key intracellular pathways that maintain junctional stability and barrier resilience. BECLIN-1 (BECN1), a central regulator of both pathways, coordinates localized membrane dynamics through its interaction with the class III phosphatidylinositol 3-kinase (PtdIns3K) PIK3C3/VPS34. Recent advances reveal that BECN1's dual role in autophagy and endocytic trafficking is crucial for maintaining barriers in diverse tissues, including the gut, skin, and blood-brain barrier. Conversely, BECN1 dysfunction can compromise junctional integrity, driving inflammatory and degenerative diseases. This review summarizes the emerging evidence linking BECN1 to membrane trafficking, stress adaptation, and immune regulation across barrier tissues, highlighting its potential as a therapeutic target for barrier-associated diseases.

The budding yeast Saccharomyces cerevisiae Atg1 complex coordinates the initiation of nonselective autophagy and consists of the Atg1 kinase, Atg13 regulatory subunit, and an S-shaped scaffold formed by Atg17, Atg29, and Atg31. In contrast, the fission yeast Schizosaccharomyces pombe Atg1 complex incorporates Atg101 instead of Atg29 and Atg31 and features a rod-shaped Atg17 scaffold. The timing of this divergence and its impact on the structural evolution of Atg17 remain unclear. Our systematic composition analysis revealed that Atg101 is found in the Atg1 complex of several budding yeast species, including two that contain both Atg29/Atg31 and Atg101. Structural modeling and negative stain EM analysis indicated that budding yeast species with Atg101 exhibit a rod-shaped Atg17. Additionally, we found that the Atg13 HORMA domain of S. pombe may possess a stabilizing cap, suggesting an alternative function for Atg101. Collectively, our findings delineate the potential evolutionary trajectories of the Atg1 complex in yeast. Abbreviations: ATG, autophagy-related; BLAST, basic local alignment search tool; C-Mad2, closed Mad2; EAT, Early Autophagy Targeting/Tethering; EM, electron microscopy; His-MBP, histidine-maltose binding protein; HORMA, Hop1, Rev7, and Mad2; IDR, intrinsically disordered region; O-Mad2, open Mad2; iTOL, Interactive Tree of Life; PAS, phagophore assembly site; PI3K, phosphatidylinositol 3-kinase; PMSF, phenylmethylsulfonyl fluoride; pTM, predicted template modeling; RMSD, root mean square deviation; TOR, target of rapamycin; TORC1, TOR complex 1.

The autophagy-related protein ATG9A is integral to cellular autophagy and lipid mobilization, yet its importance in mammalian physiology remains underexplored. Using a liver-specific conditional Atg9a knockout (Atg9a-cKO) mouse model, we uncovered critical insights into the physiological function of ATG9A in this organ. Atg9a-cKO mice exhibited hepatomegaly, abnormal hepatocyte morphology, mitochondrial fragmentation, and lipid droplet accumulation. Blood chemistry and proteomics analyses revealed elevated serum cholesterol, reduced albumin, and dysregulation of pathways related to lipid metabolism and oxidative stress responses. These findings establish an essential role for ATG9A in maintaining hepatocyte integrity, lipid trafficking, and overall liver health, offering a model for studying autophagy-related hepatic pathologies.