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Dermatology (Basel, Switzerland) 2019Autophagy, or self-eating, is an evolutionarily conserved process in which cytosol and organelles are sequestered within double-membrane vesicles that deliver the... (Review)
Review
Autophagy, or self-eating, is an evolutionarily conserved process in which cytosol and organelles are sequestered within double-membrane vesicles that deliver the contents to the lysosome/vacuole for the degradation and recycling of cytoplasmic components in eukaryotes. It is well recognized that autophagy plays an important role in maintaining cellular homeostasis under physiological and pathophysiological con-ditions and the upregulation of autophagy may serve as an adaptive process to provide nutrients and energy when under stresses. Recently, studies have illustrated that autophagy is intricately related to skin diseases. This review provides a brief synopsis of the process of autophagy and aims to elucidate the roles of autophagy in different skin diseases and to highlight the need for increased research in the field.
Topics: Autophagy; Humans; Skin Diseases
PubMed: 31269494
DOI: 10.1159/000500470 -
Medecine Sciences : M/S Mar 2017The retina is a light-sensitive tissue in the vertebrate eye that detects and processes visual images. The eye, including retina, is exposed to a variety of... (Review)
Review
The retina is a light-sensitive tissue in the vertebrate eye that detects and processes visual images. The eye, including retina, is exposed to a variety of environmental insults and stressors, among which genetic mutations and age-associated alterations that impair their function. Autophagy is a catabolic pathway that promotes the degradation and recycling of cellular components under basal and stress conditions. Proteins, lipids, and even whole organelles are engulfed in autophagosomes and delivered to the lysosome for elimination. Research has only begun to examine the role of autophagy in the visual system. Here, we review the main studies that have sought to explain autophagy's importance for visual function.
Topics: Animals; Autophagy; Humans; Photoreceptor Cells, Vertebrate; Retina; Retinal Pigment Epithelium; Vision, Ocular
PubMed: 28367817
DOI: 10.1051/medsci/20173303017 -
Biochemistry. Biokhimiia Jan 2024Autophagy is the process by which cell contents, such as aggregated proteins, dysfunctional organelles, and cell structures are sequestered by autophagosome and... (Review)
Review
Autophagy is the process by which cell contents, such as aggregated proteins, dysfunctional organelles, and cell structures are sequestered by autophagosome and delivered to lysosomes for degradation. As a process that allows the cell to get rid of non-functional components that tend to accumulate with age, autophagy has been associated with many human diseases. In this regard, the search for autophagy activators and the study of their mechanism of action is an important task for treatment of many diseases, as well as for increasing healthy life expectancy. Plants are rich sources of autophagy activators, containing large amounts of polyphenolic compounds in their composition, which can be autophagy activators in their original form, or can be metabolized by the intestinal microbiota to active compounds. This review is devoted to the plant-based autophagy activators with emphasis on the sources of their production, mechanism of action, and application in various diseases. The review also describes companies commercializing natural autophagy activators.
Topics: Humans; Autophagy; Plants; Lysosomes
PubMed: 38467543
DOI: 10.1134/S0006297924010012 -
ELife Sep 2021Removal of damaged organelles via the process of selective autophagy constitutes a major form of cellular quality control. Damaged organelles are recognized by a...
Removal of damaged organelles via the process of selective autophagy constitutes a major form of cellular quality control. Damaged organelles are recognized by a dedicated surveillance machinery, leading to the assembly of an autophagosome around the damaged organelle, prior to fusion with the degradative lysosomal compartment. Lysosomes themselves are also prone to damage and are degraded through the process of lysophagy. While early steps involve recognition of ruptured lysosomal membranes by glycan-binding galectins and ubiquitylation of transmembrane lysosomal proteins, many steps in the process, and their interrelationships, remain poorly understood, including the role and identity of cargo receptors required for completion of lysophagy. Here, we employ quantitative organelle capture and proximity biotinylation proteomics of autophagy adaptors, cargo receptors, and galectins in response to acute lysosomal damage, thereby revealing the landscape of lysosome-associated proteome remodeling during lysophagy. Among the proteins dynamically recruited to damaged lysosomes were ubiquitin-binding autophagic cargo receptors. Using newly developed lysophagic flux reporters including Lyso-Keima, we demonstrate that TAX1BP1, together with its associated kinase TBK1, are both necessary and sufficient to promote lysophagic flux in both HeLa cells and induced neurons (iNeurons). While the related receptor Optineurin (OPTN) can drive damage-dependent lysophagy when overexpressed, cells lacking either OPTN or CALCOCO2 still maintain significant lysophagic flux in HeLa cells. Mechanistically, TAX1BP1-driven lysophagy requires its N-terminal SKICH domain, which binds both TBK1 and the autophagy regulatory factor RB1CC1, and requires upstream ubiquitylation events for efficient recruitment and lysophagic flux. These results identify TAX1BP1 as a central component in the lysophagy pathway and provide a proteomic resource for future studies of the lysophagy process.
Topics: Autophagy; Humans; Lysosomes; Macroautophagy; Protein Binding; Proteomics; Ubiquitin
PubMed: 34585663
DOI: 10.7554/eLife.72328 -
Journal of the American Society of... May 2017Excessive fat intake contributes to the progression of metabolic diseases cellular injury and inflammation, a process termed lipotoxicity. Here, we investigated the...
Excessive fat intake contributes to the progression of metabolic diseases cellular injury and inflammation, a process termed lipotoxicity. Here, we investigated the role of lysosomal dysfunction and impaired autophagic flux in the pathogenesis of lipotoxicity in the kidney. In mice, a high-fat diet (HFD) resulted in an accumulation of phospholipids in enlarged lysosomes within kidney proximal tubular cells (PTCs). In isolated PTCs treated with palmitic acid, autophagic degradation activity progressively stagnated in association with impaired lysosomal acidification and excessive lipid accumulation. Pulse-chase experiments revealed that the accumulated lipids originated from cellular membranes. In mice with induced PTC-specific ablation of autophagy, PTCs of HFD-mice exhibited greater accumulation of ubiquitin-positive protein aggregates normally removed by autophagy than did PTCs of mice fed a normal diet. Furthermore, HFD-mice had no capacity to augment autophagic activity upon another pathologic stress. Autophagy ablation also exaggerated HFD-induced mitochondrial dysfunction and inflammasome activation. Moreover, renal ischemia-reperfusion induced greater injury in HFD-mice than in mice fed a normal diet, and ablation of autophagy further exacerbated this effect. Finally, we detected similarly enhanced phospholipid accumulation in enlarged lysosomes and impaired autophagic flux in the kidneys of obese patients compared with nonobese patients. These findings provide key insights regarding the pathophysiology of lipotoxicity in the kidney and clues to a novel treatment for obesity-related kidney diseases.
Topics: Animals; Autophagy; Diet, High-Fat; Kidney; Kidney Diseases; Lipid Metabolism; Lysosomes; Male; Mice; Palmitic Acid
PubMed: 27932476
DOI: 10.1681/ASN.2016070731 -
Cold Spring Harbor Perspectives in... Aug 2014Autophagy as an immune mechanism controls inflammation and acts as a cell-autonomous defense against intracellular microbes including Mycobacterium tuberculosis. An... (Review)
Review
Autophagy as an immune mechanism controls inflammation and acts as a cell-autonomous defense against intracellular microbes including Mycobacterium tuberculosis. An equally significant role of autophagy is its anti-inflammatory and tissue-sparing function. This combination of antimicrobial and anti-inflammatory actions prevents active disease in animal models. In human populations, genetic links between autophagy, inflammatory bowel disease, and susceptibility to tuberculosis provide further support to these combined roles of autophagy. The autophagic control of M. tuberculosis and prevention of progressive disease provide novel insights into physiological and immune control of tuberculosis. It also offers host-based therapeutic opportunities because autophagy can be pharmacologically modulated.
Topics: Autophagy; Humans; Mycobacterium tuberculosis; Tuberculosis, Pulmonary
PubMed: 25167980
DOI: 10.1101/cshperspect.a018481 -
Frontiers in Cellular and Infection... 2022Autophagy is an immune homeostasis process induced by multiple intracellular and extracellular signals. Inflammation is a protective response to harmful stimuli such as... (Review)
Review
Autophagy is an immune homeostasis process induced by multiple intracellular and extracellular signals. Inflammation is a protective response to harmful stimuli such as pathogen microbial infection and body tissue damage. infection elicits both autophagy and inflammation, and dysregulation of autophagy and inflammation promotes pathology. This review focuses on the interaction between autophagy and inflammation caused by infection, aiming to elaborate on the possible mechanism involved in the interaction.
Topics: Autophagy; Homeostasis; Humans; Inflammation; Porphyromonas gingivalis
PubMed: 35846745
DOI: 10.3389/fcimb.2022.892610 -
Antioxidants & Redox Signaling Mar 2023Autophagy is critical to cellular homeostasis. Emergence of the concept of regulated necrosis, such as necroptosis, ferroptosis, pyroptosis, and mitochondrial... (Review)
Review
Autophagy is critical to cellular homeostasis. Emergence of the concept of regulated necrosis, such as necroptosis, ferroptosis, pyroptosis, and mitochondrial membrane-permeability transition (MPT)-derived necrosis, has revolutionized the research into necrosis. Both altered autophagy and regulated necrosis contribute to major human diseases. Recent studies reveal an intricate interplay between autophagy and regulated necrosis. Understanding the interplay at the molecular level will provide new insights into the pathophysiology of related diseases. Among the three forms of autophagy, macroautophagy is better studied for its crosstalk with regulated necrosis. Macroautophagy seemingly can either antagonize or promote regulated necrosis, depending upon the form of regulated necrosis, the type of cells or stimuli, and other cellular contexts. This review will critically analyze recent advances in the molecular mechanisms governing the intricate dialogues between macroautophagy and main forms of regulated necrosis. The dual roles of autophagy, either pro-survival or pro-death characteristics, intricate the mechanistic relationship between autophagy and regulated necrosis at molecular level in various pathological conditions. Meanwhile, key components of regulated necrosis are also involved in the regulation of autophagy, which further complicates the interrelationship. Resolving the controversies over causation between altered autophagy and a specific form of regulated necrosis requires approaches that are more definitive, where rigorous evaluation of autophagic flux and the development of more reliable and specific methods to quantify each form of necrosis will be essential. The relationship between chaperone-mediated autophagy or microautophagy and regulated necrosis remains largely unstudied. 38, 550-580.
Topics: Humans; Apoptosis; Necrosis; Pyroptosis; Ferroptosis; Autophagy
PubMed: 36053716
DOI: 10.1089/ars.2022.0110 -
Zhejiang Da Xue Xue Bao. Yi Xue Ban =... May 2016Autophagy refers to a catabolic process,in which the damaged organelles or biological macromolecules, such as protein aggregates, are degraded via lysosome. The...
Autophagy refers to a catabolic process,in which the damaged organelles or biological macromolecules, such as protein aggregates, are degraded via lysosome. The completion of autophagy depends on a series of autophagy-related genes (Atgs) and many upstream regulatory molecules. Zinc is an essential trace element, and plays an important role in the process of autophagy as a component of enzymes and structural proteins like zinc transporters or zinc finger protein. The regulation of autophagy is closely associated with the zinc ion homeostasis. In addition, many studies suggest that the protective effects of zinc on cells are likely to be done by autophagy. This review aims to summarize the current research progress and discuss the reciprocal regulation mechanism between zinc and autophagy, which may provide insights into the intricate roles of autophagy in diseases and find novel strategies for treatment and prevention of human diseases.
Topics: Animals; Autophagy; Homeostasis; Humans; Proteins; Zinc
PubMed: 27651198
DOI: 10.3785/j.issn.1008-9292.2019.05.15 -
MBio Aug 2023Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as the causative agent of the recent COVID-19 pandemic, continues representing one of the main health... (Review)
Review
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as the causative agent of the recent COVID-19 pandemic, continues representing one of the main health concerns worldwide. Autophagy, in addition to its role in cellular homeostasis and metabolism, plays an important part for the host antiviral immunity. However, viruses including SARS-CoV-2 have evolved diverse mechanisms to not only overcome autophagy's antiviral pressure but also manipulate its machinery in order to enhance viral replication and propagation. Here, we discuss our current knowledge on the impact that autophagy exerts on SARS-CoV-2 replication, as well as the different counteracting measures that this virus has developed to manipulate autophagy's complex machinery. Some of the elements regarding this interplay may become future therapeutic targets in the fight against SARS-CoV-2.
Topics: Humans; SARS-CoV-2; COVID-19; Pandemics; Antiviral Agents; Autophagy
PubMed: 37436071
DOI: 10.1128/mbio.01020-23