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Uribe-Carretero E, Rey V, Fuentes JM, Tamargo-Gómez I. Lysosomal Dysfunction: Connecting the Dots in the Landscape of Human Diseases. BIOLOGY 2024; 13:34. [PMID: 38248465 PMCID: PMC10813815 DOI: 10.3390/biology13010034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/23/2024]
Abstract
Lysosomes are the main organelles responsible for the degradation of macromolecules in eukaryotic cells. Beyond their fundamental role in degradation, lysosomes are involved in different physiological processes such as autophagy, nutrient sensing, and intracellular signaling. In some circumstances, lysosomal abnormalities underlie several human pathologies with different etiologies known as known as lysosomal storage disorders (LSDs). These disorders can result from deficiencies in primary lysosomal enzymes, dysfunction of lysosomal enzyme activators, alterations in modifiers that impact lysosomal function, or changes in membrane-associated proteins, among other factors. The clinical phenotype observed in affected patients hinges on the type and location of the accumulating substrate, influenced by genetic mutations and residual enzyme activity. In this context, the scientific community is dedicated to exploring potential therapeutic approaches, striving not only to extend lifespan but also to enhance the overall quality of life for individuals afflicted with LSDs. This review provides insights into lysosomal dysfunction from a molecular perspective, particularly in the context of human diseases, and highlights recent advancements and breakthroughs in this field.
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Affiliation(s)
- Elisabet Uribe-Carretero
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, 10003 Caceres, Spain; (E.U.-C.)
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativa, Instituto de Salud Carlos III (CIBER-CIBERNED-ISCIII), 28029 Madrid, Spain
- Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), 10003 Caceres, Spain
| | - Verónica Rey
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Jose Manuel Fuentes
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, 10003 Caceres, Spain; (E.U.-C.)
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativa, Instituto de Salud Carlos III (CIBER-CIBERNED-ISCIII), 28029 Madrid, Spain
- Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), 10003 Caceres, Spain
| | - Isaac Tamargo-Gómez
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
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Tooze SA, Zhang W, Lazzeri G, Gahlot D, Thukral L, Covino R, Nishimura T. Membrane association of the ATG8 conjugation machinery emerges as a key regulatory feature for autophagosome biogenesis. FEBS Lett 2024; 598:107-113. [PMID: 37259601 PMCID: PMC10952647 DOI: 10.1002/1873-3468.14676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/10/2023] [Accepted: 05/10/2023] [Indexed: 06/02/2023]
Abstract
Autophagy is a highly conserved intracellular pathway that is essential for survival in all eukaryotes. In healthy cells, autophagy is used to remove damaged intracellular components, which can be as simple as unfolded proteins or as complex as whole mitochondria. Once the damaged component is captured, the autophagosome engulfs it and closes, isolating the content from the cytoplasm. The autophagosome then fuses with the late endosome and/or lysosome to deliver its content to the lysosome for degradation. Formation of the autophagosome, sequestration or capture of content, and closure all require the ATG proteins, which constitute the essential core autophagy protein machinery. This brief 'nutshell' will highlight recent data revealing the importance of small membrane-associated domains in the ATG proteins. In particular, recent findings from two parallel studies reveal the unexpected key role of α-helical structures in the ATG8 conjugation machinery and ATG8s. These studies illustrate how unique membrane association modules can control the formation of autophagosomes.
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Affiliation(s)
- Sharon A. Tooze
- Molecular Cell Biology of Autophagy LaboratoryThe Francis Crick InstituteLondonUK
| | - Wenxin Zhang
- Molecular Cell Biology of Autophagy LaboratoryThe Francis Crick InstituteLondonUK
| | | | - Deepanshi Gahlot
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative Research (AcSIR)GhaziabadIndia
| | - Lipi Thukral
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative Research (AcSIR)GhaziabadIndia
| | | | - Taki Nishimura
- PRESTO, Japan Science and Technology AgencyTokyoJapan
- Department of Biochemistry and Molecular Biology, Graduate School of MedicineThe University of TokyoJapan
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Yu Q, Li C, Niu Q, Wang J, Che Z, Lei K, Ren H, Ma B, Ren Y, Luo P, Fan Z, Zhang H, Liu Z, Tipoe GL, Xiao J. Hepatic COX1 loss leads to impaired autophagic flux and exacerbates nonalcoholic steatohepatitis. Acta Pharm Sin B 2023. [DOI: 10.1016/j.apsb.2023.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
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Tanaka Y, Kusumoto SY, Honma Y, Takeya K, Eto M. Overexpression of progranulin increases pathological protein accumulation by suppressing autophagic flux. Biochem Biophys Res Commun 2022; 611:78-84. [PMID: 35483222 DOI: 10.1016/j.bbrc.2022.04.064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/13/2022] [Indexed: 01/01/2023]
Abstract
Progranulin (PGRN) haploinsufficiency from autosomal dominant mutations in the PGRN gene causes frontotemporal lobar degeneration, which is characterized by cytoplasmic inclusions predominantly containing TDP-43 (FTLD-TDP). PGRN supplementation for patients with a PGRN gene mutation has recently been proposed as a therapeutic strategy to suppress FTLD-TDP. However, it currently remains unclear whether excessive amounts of PGRN are beneficial or harmful. We herein report the effects of PGRN overexpression on autophagic flux in a cultured cell model. PGRN overexpression increased the level of an autophagosome marker without promoting autophagosome formation and decreased the signal intensity of an autolysosome marker, indicating the suppression of autophagic flux due to reductions in the formation of autolysosomes. Assessments of lysosome numbers and biogenesis using LysoTracker and cells stably expressing TFEB-GFP, respectively, indicated that PGRN overexpression increased the lysosome numbers without lysosomal biogenesis. These results suggest that PGRN overexpression suppressed autophagic flux by inhibiting autophagosome-lysosome fusion. Moreover, PGRN overexpression enhanced polyglutamine aggregation and aggregate-prone TDP-43 accumulation, indicating that the suppression of autophagic flux by excessive amounts of PGRN worsens the pathology of neurodegenerative diseases.
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Affiliation(s)
- Yoshinori Tanaka
- Biochemistry Unit, Faculty of Veterinary Medicine, Okayama University of Science, Imabari-shi, Ehime, Japan.
| | - Shun-Ya Kusumoto
- Biochemistry Unit, Faculty of Veterinary Medicine, Okayama University of Science, Imabari-shi, Ehime, Japan
| | - Yuki Honma
- Biochemistry Unit, Faculty of Veterinary Medicine, Okayama University of Science, Imabari-shi, Ehime, Japan
| | - Kosuke Takeya
- Biochemistry Unit, Faculty of Veterinary Medicine, Okayama University of Science, Imabari-shi, Ehime, Japan
| | - Masumi Eto
- Biochemistry Unit, Faculty of Veterinary Medicine, Okayama University of Science, Imabari-shi, Ehime, Japan
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Ding H, Ge G, Tseng Y, Ma Y, Zhang J, Liu J. Hepatic autophagy fluctuates during the development of non-alcoholic fatty liver disease. Ann Hepatol 2021; 19:516-522. [PMID: 32553647 DOI: 10.1016/j.aohep.2020.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 02/04/2023]
Abstract
INTRODUCTION AND OBJECTIVES Autophagy has emerged as a critical regulatory pathway in non-alcoholic fatty liver disease (NAFLD). However, the variability of hepatic autophagy during NAFLD development remains controversial. This study aimed to elucidate the dynamics of hepatic autophagy and its underlying mechanism during NAFLD development both in vivo and in vitro. MATERIALS AND METHODS Autophagy markers were evaluated in the livers of mice fed a high fat diet or a methionine-choline-deficient diet and in HepG2 cells treated with palmitic acid (PA) by western blotting. Intrahepatic and intracellular triacylglycerol levels were assessed using biochemical quantification and lipid staining. Autophagic flux was monitored using an LC3 turnover assay and tandem mRFP-GFP-LC3 fluorescence analysis. RESULTS Hepatic autophagy was enhanced in early stages but blocked at later stages of NAFLD development both in vivo and in vitro. Analysis of autophagic flux revealed that both autophagic synthesis and degradation were initially activated and progressively inhibited afterwards. The activation of mammalian target of rapamycin complex 1 (mTORC1), a central regulator of autophagy, was found to be negatively correlated with autophagic synthesis; moreover, pharmacological inhibition of mTORC1 by rapamycin alleviated hepatic steatosis through recovery of autophagic flux in hepatocytes with prolonged PA treatment. CONCLUSIONS Hepatic autophagy fluctuates during the development of NAFLD in which mTORC1 signalling plays a critical regulatory role, suggesting a therapeutic potential of autophagy modulation by targeting the mTORC1 signalling pathway in NAFLD.
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Affiliation(s)
- Hao Ding
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Ge Ge
- Department of Dermatology, Air Force Medical Center, Beijing, China; China Medical University, Shenyang, China
| | - Yujen Tseng
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Yanyun Ma
- Human Phenome Institute, Fudan University, Shanghai, 201203, China; Six-sector Industrial Research Institute, Fudan University, Shanghai, 200433, China; Ministry of Education Key Laboratory of Contemporary Anthropology, Department of Anthropology and Human Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jun Zhang
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Jie Liu
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai, China.
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The Autophagy Machinery in Human-Parasitic Protists; Diverse Functions for Universally Conserved Proteins. Cells 2021; 10:cells10051258. [PMID: 34069694 PMCID: PMC8161075 DOI: 10.3390/cells10051258] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/31/2022] Open
Abstract
Autophagy is a eukaryotic cellular machinery that is able to degrade large intracellular components, including organelles, and plays a pivotal role in cellular homeostasis. Target materials are enclosed by a double membrane vesicle called autophagosome, whose formation is coordinated by autophagy-related proteins (ATGs). Studies of yeast and Metazoa have identified approximately 40 ATGs. Genome projects for unicellular eukaryotes revealed that some ATGs are conserved in all eukaryotic supergroups but others have arisen or were lost during evolution in some specific lineages. In spite of an apparent reduction in the ATG molecular machinery found in parasitic protists, it has become clear that ATGs play an important role in stage differentiation or organelle maintenance, sometimes with an original function that is unrelated to canonical degradative autophagy. In this review, we aim to briefly summarize the current state of knowledge in parasitic protists, in the light of the latest important findings from more canonical model organisms. Determining the roles of ATGs and the diversity of their functions in various lineages is an important challenge for understanding the evolutionary background of autophagy.
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Claude-Taupin A, Morel E. Phosphoinositides: Functions in autophagy-related stress responses. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158903. [PMID: 33578048 DOI: 10.1016/j.bbalip.2021.158903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/29/2021] [Accepted: 02/06/2021] [Indexed: 01/02/2023]
Abstract
Phosphoinositides are key lipids in eukaryotes, regulating organelles' identity and function. Their synthesis and turnover require specific phosphorylation/dephosphorylation events that are ensured by dedicated lipid kinases and phosphatases, which modulate the structure of the inositol ring by adding or removing phosphates on positions 3, 4 or 5. Beside their implication in intracellular signalization and cytoskeleton dynamics, phosphoinositides are essential for vesicular transport along intracellular trafficking routes, by providing molecular scaffolds to membrane related events such as budding, fission or fusion. Robust and detailed literature demonstrated that some members of the phosphoinositides family are crucial for the autophagy pathway, acting as fine tuners and regulators. In this review, we discuss the known functions of phosphoinositides in autophagy canonical processes, such as during autophagosome formation, as well as the importance of phosphoinositides in organelle-based processes directly connected to the autophagic machinery, such as endosomal dynamics, ciliogenesis and innate immunity.
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Affiliation(s)
- Aurore Claude-Taupin
- Institut Necker Enfants-Malades (INEM), INSERM U1151-CNRS UMR 8253, Université de Paris, Paris, France
| | - Etienne Morel
- Institut Necker Enfants-Malades (INEM), INSERM U1151-CNRS UMR 8253, Université de Paris, Paris, France.
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Abstract
Autophagy requires the formation of membrane vesicles, known as autophagosomes, that engulf cellular cargoes and subsequently recruit lysosomal hydrolases for the degradation of their contents. A number of autophagy-related proteins act to mediate the de novo biogenesis of autophagosomes and vesicular trafficking events that are required for autophagy. Of these proteins, ATG16L1 is a key player that has important functions at various stages of autophagy. Numerous recent studies have begun to unravel novel activities of ATG16L1, including interactions with proteins and lipids, and how these mediate its role during autophagy and autophagy-related processes. Various domains have been identified within ATG16L1 that mediate its functions in recognising single and double membranes and activating subsequent autophagy-related enzymatic activities required for the recruitment of lysosomes. These recent findings, as well as the historical discovery of ATG16L1, pathological relevance, unresolved questions and contradictory observations, will be discussed here.
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Affiliation(s)
- Noor Gammoh
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK
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Tan S, Yang S, Chen G, Zhu L, Sun Z, Chen S. Trehalose alleviates apoptosis by protecting the autophagy-lysosomal system in alveolar macrophages during human silicosis. Life Sci 2020; 257:118043. [PMID: 32621922 DOI: 10.1016/j.lfs.2020.118043] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/12/2020] [Accepted: 06/29/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Alveolar macrophages (AMs) are the primary targets of silicosis. Blockade of autophagy may aggravate the apoptosis of AMs. Trehalose (Tre), a transcription factor EB (TFEB) activator, may impact the autophagy-lysosomal system in AMs during silicosis. However, the mechanism by which Tre acts upon AMs in silicosis is unknown. METHODS We collected AMs from twenty male workers exposed to silica and divided them into observer and silicosis patient groups. AMs from the two groups were then exposed to Tre. Western blot was used to measure the expression of autophagy-associated proteins. Lysosomal-associated membrane protein 1 (LAMP1) expression was observed using immunofluorescence and western blot. Apoptosis of the AMs was detected by TUNEL assay and western blot. RESULTS Tre induced localization of TFEB to the nucleus in the AMs of both groups. After Tre exposure, LAMP1 levels increased and LC3 levels decreased in the AMs of both groups, suggesting that Tre may increase the function of the autophagy-lysosomal system. The LC3-II/I ratio in the Tre-exposed AMs was lower than in the AMs not exposed to Tre. The LC3-II/I ratio in AMs subjected to Tre plus Bafilomycin (Baf) was higher than the ratio in cells exposed to Tre or Baf individually. Additionally, p62 levels decreased after Tre stimulation in the AMs of both groups. This indicates that Tre may accelerate the process of autophagic degradation. We also found decreased levels of cleaved caspase-3 after Tre treatment in the AMs of both groups. However, p-mTOR (Ser2448) and p-mTOR (Ser2481) levels did not change significantly after Tre treatment, suggesting that the mTOR signaling pathway was not affected by Tre treatment. CONCLUSION Our findings suggest that the restoration of autophagy-lysosomal function by Tre may be a potential protective strategy against silicosis.
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Affiliation(s)
- Shiyi Tan
- School of Medicine, Hunan Normal University, Changsha, Hunan Province 410013, PR China; Key Laboratory of Molecular Epidemiology of Hunan Province, Hunan Normal University Changsha, Hunan Province 410013, PR China
| | - Shang Yang
- School of Medicine, Hunan Normal University, Changsha, Hunan Province 410013, PR China; Key Laboratory of Molecular Epidemiology of Hunan Province, Hunan Normal University Changsha, Hunan Province 410013, PR China
| | - Gang Chen
- Department of Pneumoconiosis, Beidaihe Sanitarium for China Coal Miners, Qinhuangdao, Hebei Province 066104, PR China
| | - Li Zhu
- Department of Pneumoconiosis, Beidaihe Sanitarium for China Coal Miners, Qinhuangdao, Hebei Province 066104, PR China
| | - Zhiqian Sun
- Department of Pneumoconiosis, Beidaihe Sanitarium for China Coal Miners, Qinhuangdao, Hebei Province 066104, PR China
| | - Shi Chen
- School of Medicine, Hunan Normal University, Changsha, Hunan Province 410013, PR China.
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