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Jafari M, Macho-González A, Diaz A, Lindenau K, Santiago-Fernández O, Zeng M, Massey AC, de Cabo R, Kaushik S, Cuervo AM. Calorie restriction and calorie-restriction mimetics activate chaperone-mediated autophagy. Proc Natl Acad Sci U S A 2024; 121:e2317945121. [PMID: 38889154 PMCID: PMC11214046 DOI: 10.1073/pnas.2317945121] [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: 10/17/2023] [Accepted: 05/20/2024] [Indexed: 06/20/2024] Open
Abstract
Chaperone-mediated autophagy (CMA) is part of the mammalian cellular proteostasis network that ensures protein quality control, maintenance of proteome homeostasis, and proteome changes required for the adaptation to stress. Loss of proteostasis is one of the hallmarks of aging. CMA decreases with age in multiple rodent tissues and human cell types. A decrease in lysosomal levels of the lysosome-associated membrane protein type 2A (LAMP2A), the CMA receptor, has been identified as a main reason for declined CMA in aging. Here, we report constitutive activation of CMA with calorie restriction (CR), an intervention that extends healthspan, in old rodent livers and in an in vitro model of CR with cultured fibroblasts. We found that CR-mediated upregulation of CMA is due to improved stability of LAMP2A at the lysosome membrane. We also explore the translational value of our observations using calorie-restriction mimetics (CRMs), pharmacologically active substances that reproduce the biochemical and functional effects of CR. We show that acute treatment of old mice with CRMs also robustly activates CMA in several tissues and that this activation is required for the higher resistance to lipid dietary challenges conferred by treatment with CRMs. We conclude that part of the beneficial effects associated with CR/CRMs could be a consequence of the constitutive activation of CMA mediated by these interventions.
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Affiliation(s)
- Maryam Jafari
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Adrián Macho-González
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Antonio Diaz
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Kristen Lindenau
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Olaya Santiago-Fernández
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Mei Zeng
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Ashish C. Massey
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, Baltimore, MD21224
| | - Susmita Kaushik
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, BronxNY10461
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY10461
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY10461
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2
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Maestri A, Garagnani P, Pedrelli M, Hagberg CE, Parini P, Ehrenborg E. Lipid droplets, autophagy, and ageing: A cell-specific tale. Ageing Res Rev 2024; 94:102194. [PMID: 38218464 DOI: 10.1016/j.arr.2024.102194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 12/22/2023] [Accepted: 01/08/2024] [Indexed: 01/15/2024]
Abstract
Lipid droplets are the essential organelle for storing lipids in a cell. Within the variety of the human body, different cells store, utilize and release lipids in different ways, depending on their intrinsic function. However, these differences are not well characterized and, especially in the context of ageing, represent a key factor for cardiometabolic diseases. Whole body lipid homeostasis is a central interest in the field of cardiometabolic diseases. In this review we characterize lipid droplets and their utilization via autophagy and describe their diverse fate in three cells types central in cardiometabolic dysfunctions: adipocytes, hepatocytes, and macrophages.
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Affiliation(s)
- Alice Maestri
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Paolo Garagnani
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy; IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Matteo Pedrelli
- Cardio Metabolic Unit, Department of Laboratory Medicine, and Department of Medicine (Huddinge), Karolinska Institutet, Stockholm, Sweden; Medicine Unit of Endocrinology, Theme Inflammation and Ageing, Karolinska University Hospital, Stockholm, Sweden
| | - Carolina E Hagberg
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Paolo Parini
- Cardio Metabolic Unit, Department of Laboratory Medicine, and Department of Medicine (Huddinge), Karolinska Institutet, Stockholm, Sweden; Medicine Unit of Endocrinology, Theme Inflammation and Ageing, Karolinska University Hospital, Stockholm, Sweden
| | - Ewa Ehrenborg
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
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3
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Immunoexpression Pattern of Autophagy Markers in Developing and Postnatal Kidneys of Dab1−/−(yotari) Mice. Biomolecules 2023; 13:biom13030402. [PMID: 36979337 PMCID: PMC10046325 DOI: 10.3390/biom13030402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 02/17/2023] [Accepted: 02/19/2023] [Indexed: 02/24/2023] Open
Abstract
The purpose of this study was to compare the immunofluorescence patterns of autophagic markers: Light chain 3 beta (LC3B), Glucose regulating protein 78 (GRP78), Heat shock cognate 71 (HSC70) and Lysosomal-associated membrane protein 2A (LAMP2A) in the developing and postnatal kidneys of Dab1−/− (yotari) mice to those of wild-type samples. Embryos were obtained on gestation days 13.5 and 15.5 (E13.5 and E15.5), and adult animals were sacrificed at postnatal days 4, 11 and 14 (P4, P11, and P14). After fixation and dehydration, paraffin-embedded kidney tissues were sectioned and incubated with specific antibodies. Using an immunofluorescence microscope, sections were analyzed. For statistical analysis, a two-way ANOVA test and a Tukey’s multiple comparison test were performed with a probability level of p < 0.05. A significant increase in GRP78 and LAMP2A expression was observed in the renal vesicles and convoluted tubules of yotari in embryonic stages. In postnatal kidneys, all observed proteins showed higher signal intensities in proximal and distal convoluted tubules of yotari, while a higher percentage of LC3B-positive cells was also observed in glomeruli. Our findings suggest that all of the examined autophagic markers play an important role in normal kidney development, as well as the potential importance of these proteins in renal pathology, where they primarily serve a protective function and thus may be used as diagnostic and therapeutic targets.
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Madrigal-Matute J, de Bruijn J, van Kuijk K, Riascos-Bernal DF, Diaz A, Tasset I, Martín-Segura A, Gijbels MJJ, Sander B, Kaushik S, Biessen EAL, Tiano S, Bourdenx M, Krause GJ, McCracken I, Baker AH, Jin H, Sibinga NES, Bravo-Cordero JJ, Macian F, Singh R, Rensen PCN, Berbée JFP, Pasterkamp G, Sluimer JC, Cuervo AM. Protective role of chaperone-mediated autophagy against atherosclerosis. Proc Natl Acad Sci U S A 2022; 119:e2121133119. [PMID: 35363568 PMCID: PMC9168839 DOI: 10.1073/pnas.2121133119] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/14/2022] [Indexed: 12/11/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) contributes to regulation of energy homeostasis by timely degradation of enzymes involved in glucose and lipid metabolism. Here, we report reduced CMA activity in vascular smooth muscle cells and macrophages in murine and human arteries in response to atherosclerotic challenges. We show that in vivo genetic blockage of CMA worsens atherosclerotic pathology through both systemic and cell-autonomous changes in vascular smooth muscle cells and macrophages, the two main cell types involved in atherogenesis. CMA deficiency promotes dedifferentiation of vascular smooth muscle cells and a proinflammatory state in macrophages. Conversely, a genetic mouse model with up-regulated CMA shows lower vulnerability to proatherosclerotic challenges. We propose that CMA could be an attractive therapeutic target against cardiovascular diseases.
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Affiliation(s)
- Julio Madrigal-Matute
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Jenny de Bruijn
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
| | - Kim van Kuijk
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
- Institute of Experimental Medicine and Systems Biology, Faculty of Medicine, RWTH Aachen University, 52074 Aachen, Germany
| | | | - Antonio Diaz
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Inmaculada Tasset
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Adrián Martín-Segura
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Marion J. J. Gijbels
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
- School for Oncology and Developmental Biology (GROW), Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
- Department of Medical Biochemistry, Experimental Vascular Biology, Amsterdam University Medical Centers, University of Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Bianca Sander
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
| | - Susmita Kaushik
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Erik A. L. Biessen
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
- Institute for Molecular Cardiovascular Research, RWTH Aachen University, 52074 Aachen, Germany
| | - Simoni Tiano
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Mathieu Bourdenx
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Gregory J. Krause
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Ian McCracken
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Andrew H. Baker
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Han Jin
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
| | - Nicholas E. S. Sibinga
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Jose Javier Bravo-Cordero
- Division of Hematology and Medical Oncology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Fernando Macian
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Rajat Singh
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Patrick C. N. Rensen
- Section of Endocrinology, Department of Internal Medicine, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Jimmy F. P. Berbée
- Section of Endocrinology, Department of Internal Medicine, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Gerard Pasterkamp
- Experimental Cardiology Laboratory, Department of Cardiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Judith C. Sluimer
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Ana Maria Cuervo
- Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461
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5
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Chaperone-Mediated Autophagy in Neurodegenerative Diseases and Acute Neurological Insults in the Central Nervous System. Cells 2022; 11:cells11071205. [PMID: 35406769 PMCID: PMC8997510 DOI: 10.3390/cells11071205] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/27/2022] [Accepted: 03/30/2022] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an important function that mediates the degradation of intracellular proteins and organelles. Chaperone-mediated autophagy (CMA) degrades selected proteins and has a crucial role in cellular proteostasis under various physiological and pathological conditions. CMA dysfunction leads to the accumulation of toxic protein aggregates in the central nervous system (CNS) and is involved in the pathogenic process of neurodegenerative diseases, including Parkinson’s disease and Alzheimer’s disease. Previous studies have suggested that the activation of CMA to degrade aberrant proteins can provide a neuroprotective effect in the CNS. Recent studies have shown that CMA activity is upregulated in damaged neural tissue following acute neurological insults, such as cerebral infarction, traumatic brain injury, and spinal cord injury. It has been also suggested that various protein degradation mechanisms are important for removing toxic aberrant proteins associated with secondary damage after acute neurological insults in the CNS. Therefore, enhancing the CMA pathway may induce neuroprotective effects not only in neurogenerative diseases but also in acute neurological insults. We herein review current knowledge concerning the biological mechanisms involved in CMA and highlight the role of CMA in neurodegenerative diseases and acute neurological insults. We also discuss the possibility of developing CMA-targeted therapeutic strategies for effective treatments.
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Yuan Z, Wang S, Tan X, Wang D. New Insights into the Mechanisms of Chaperon-Mediated Autophagy and Implications for Kidney Diseases. Cells 2022; 11:cells11030406. [PMID: 35159216 PMCID: PMC8834181 DOI: 10.3390/cells11030406] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 02/04/2023] Open
Abstract
Chaperone-mediated autophagy (CMA) is a separate type of lysosomal proteolysis, characterized by its selectivity of substrate proteins and direct translocation into lysosomes. Recent studies have declared the involvement of CMA in a variety of physiologic and pathologic situations involving the kidney, and it has emerged as a potential target for the treatment of kidney diseases. The role of CMA in kidney diseases is context-dependent and appears reciprocally with macroautophagy. Among the renal resident cells, the proximal tubule exhibits a high basal level of CMA activity, and restoration of CMA alleviates the aging-related tubular alternations. The level of CMA is up-regulated under conditions of oxidative stress, such as in acute kidney injury, while it is declined in chronic kidney disease and aging-related kidney diseases, leading to the accumulation of oxidized substrates. Suppressed CMA leads to the kidney hypertrophy in diabetes mellitus, and the increase of CMA contributes to the progress and chemoresistance in renal cell carcinoma. With the progress on the understanding of the cellular functions and uncovering the clinical scenario, the application of targeting CMA in the treatment of kidney diseases is expected.
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Liao Z, Wang B, Liu W, Xu Q, Hou L, Song J, Guo Q, Li N. Dysfunction of chaperone-mediated autophagy in human diseases. Mol Cell Biochem 2021; 476:1439-1454. [PMID: 33389491 DOI: 10.1007/s11010-020-04006-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 11/24/2020] [Indexed: 12/19/2022]
Abstract
Chaperone-mediated autophagy (CMA), one of the degradation pathways of proteins, is highly selective to substrates that have KFERQ-like motif. In this process, the substrate proteins are first recognized by the chaperone protein, heat shock cognate protein 70 (Hsc70), then delivered to lysosomal membrane surface where the single-span lysosomal receptor, lysosome-associated membrane protein type 2A (LAMP2A) can bind to the substrate proteins to form a 700 kDa protein complex that allows them to translocate into the lysosome lumen to be degraded by the hydrolytic enzymes. This degradation pathway mediated by CMA plays an important role in regulating glucose and lipid metabolism, transcription, DNA reparation, cell cycle, cellular response to stress and consequently, regulating many aging-associated human diseases, such as neurodegeneration, cancer and metabolic disorders. In this review, we provide an overview of current research on the functional roles of CMA primarily from a perspective of understanding and treating human diseases and also discuss its potential applications for diseases.
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Affiliation(s)
- Zhaozhong Liao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Bin Wang
- College of Electronic Information, Micro-Nano Technology College, Qingdao University, Qingdao, China
| | - Wenjing Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Qian Xu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Lin Hou
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Jinlian Song
- Department of Laboratory, The Affiliated Women and Children's Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Qingming Guo
- Biotherapy Center, Clinical Laboratory, Qingdao Central Hospital, The Second Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ning Li
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Qingdao University, Qingdao, China.
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8
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Abstract
Autophagy is an adaptive catabolic process functioning to promote cell survival in the event of inappropriate living conditions such as nutrient shortage and to cope with diverse cytotoxic insults. It is regarded as one of the key survival mechanisms of living organisms. Cells undergo autophagy to accomplish the lysosomal digestion of intracellular materials including damaged proteins, organelles, and foreign bodies, in a bulk, non-selective or a cargo-specific manner. Studies in the past decades have shed light on the association of autophagy pathways with various diseases and also highlighted the therapeutic value of autophagy modulation. Hence, it is crucial to develop effective approaches for monitoring intracellular autophagy dynamics, as a comprehensive account of methodology establishment is far from complete. In this review, we aim to provide an overview of the major current fluorescence-based techniques utilized for visualizing, sensing or measuring autophagic activities in cells or tissues, which are categorized firstly by targets detected and further by the types of fluorescence tools. We will mainly focus on the working mechanisms of these techniques, put emphasis on the insight into their roles in biomedical science and provide perspectives on the challenges and future opportunities in this field.
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Affiliation(s)
- Siyang Ding
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne Victoria 3086, Australia.
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Arias E, Cuervo AM. Pros and Cons of Chaperone-Mediated Autophagy in Cancer Biology. Trends Endocrinol Metab 2020; 31:53-66. [PMID: 31699565 PMCID: PMC7020649 DOI: 10.1016/j.tem.2019.09.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/16/2019] [Accepted: 09/17/2019] [Indexed: 11/18/2022]
Abstract
Autophagy contributes to cellular quality control and energetics through lysosomal breakdown and recycling of essential cellular components. Chaperone-mediated autophagy (CMA) adds to these autophagic functions the ability to timely and selectively degrade single tagged proteins to terminate their cellular function and, in this way, participate in the regulation of multiple cellular processes. Many cancer cells upregulate CMA for protumorigenic and prosurvival purposes. However, growing evidence supports a physiological role for CMA in limiting malignant transformation. Understanding the mechanisms behind this functional switch of CMA from antioncogenic to pro-oncogenic is fundamental for targeting CMA in cancer treatment. We summarize current understanding of CMA functions in cancer biology and discuss the basis for its context-dependent dual role in oncogenesis.
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Affiliation(s)
- Esperanza Arias
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Ana Maria Cuervo
- Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Development and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Abstract
Chaperone-mediated autophagy (CMA) was the first studied process that indicated that degradation of intracellular components by the lysosome can be selective - a concept that is now well accepted for other forms of autophagy. Lysosomes can degrade cellular cytosol in a nonspecific manner but can also discriminate what to target for degradation with the involvement of a degradation tag, a chaperone and a sophisticated mechanism to make the selected proteins cross the lysosomal membrane through a dedicated translocation complex. Recent studies modulating CMA activity in vivo using transgenic mouse models have demonstrated that selectivity confers on CMA the ability to participate in the regulation of multiple cellular functions. Timely degradation of specific cellular proteins by CMA modulates, for example, glucose and lipid metabolism, DNA repair, cellular reprograming and the cellular response to stress. These findings expand the physiological relevance of CMA beyond its originally identified role in protein quality control and reveal that CMA failure with age may aggravate diseases, such as ageing-associated neurodegeneration and cancer.
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Affiliation(s)
- Susmita Kaushik
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA. .,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA. .,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA.
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11
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You Y, Li WZ, Zhang S, Hu B, Li YX, Li HD, Tang HH, Li QW, Guan YY, Liu LX, Bao WL, Shen X. SNX10 mediates alcohol-induced liver injury and steatosis by regulating the activation of chaperone-mediated autophagy. J Hepatol 2018; 69:129-141. [PMID: 29452206 DOI: 10.1016/j.jhep.2018.01.038] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 01/03/2018] [Accepted: 01/30/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Alcoholic liver disease (ALD) is a major cause of morbidity and mortality worldwide. However, the cellular defense mechanisms underlying ALD are not well understood. Recent studies highlighted the involvement of chaperone-mediated autophagy (CMA) in regulating hepatic lipid metabolism. Sorting nexin (SNX)-10 has a regulatory function in endolysosomal trafficking and stabilisation. Here, we investigated the roles of SNX10 in CMA activation and in the pathogenesis of alcohol-induced liver injury and steatosis. METHODS Snx10 knockout (Snx10 KO) mice and their wild-type (WT) littermates fed either the Lieber-DeCarli liquid alcohol diet or a control liquid diet, and primary cultured WT and Snx10 KO hepatocytes stimulated with ethanol, were used as in vivo and in vitro ALD models, respectively. Activation of CMA, liver injury parameters, inflammatory cytokines, oxidative stress and lipid metabolism were measured. RESULTS Compared with WT littermates, Snx10 KO mice exhibited a significant amelioration in ethanol-induced liver injury and hepatic steatosis. Both in vivo and in vitro studies showed that SNX10 deficiency upregulated lysosome-associated membrane protein type 2A (LAMP-2A) expression and CMA activation, which could be reversed by SNX10 overexpression in vitro. LAMP-2A interference confirmed that the upregulation of Nrf2 and AMPK signalling pathways induced by SNX10 deficiency relied on CMA activation. Pull-down assays revealed an interaction between SNX10 and cathepsin A (CTSA), a key enzyme involved in LAMP-2A degradation. Deficiency in SNX10 inhibited CTSA maturation and increased the stability of LAMP-2A, resulting in an increase in CMA activity. CONCLUSIONS SNX10 controls CMA activity by mediating CTSA maturation, and, thus, has an essential role in alcohol-induced liver injury and steatosis. Our results provide evidence for SNX10 as a potential promising therapeutic target for preventing or ameliorating liver injury in ALD. LAY SUMMARY Alcoholic liver disease is a major cause of morbidity and mortality worldwide. Recent studies highlight the involvement of chaperone-mediated autophagy (CMA) in regulating hepatic lipid metabolism. Our study reveals that deficiency of sorting nexin (SNX) 10 increases the stability of LAMP-2A by inhibiting cathepsin A maturation, resulting in the increase of CMA activity and, thus, alleviates alcohol-induced liver injury and steatosis.
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Affiliation(s)
- Yan You
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Wan-Zhen Li
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Sulin Zhang
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Bin Hu
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Yue-Xuan Li
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Hai-Dong Li
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Huan-Huan Tang
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Qian-Wen Li
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Yun-Yun Guan
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Li-Xin Liu
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Wei-Lian Bao
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Xiaoyan Shen
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China.
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12
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Shi R, Guberman M, Kirshenbaum LA. Mitochondrial quality control: The role of mitophagy in aging. Trends Cardiovasc Med 2018; 28:246-260. [DOI: 10.1016/j.tcm.2017.11.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 12/25/2022]
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Tekirdag K, Cuervo AM. Chaperone-mediated autophagy and endosomal microautophagy: Joint by a chaperone. J Biol Chem 2018; 293:5414-5424. [PMID: 29247007 PMCID: PMC5900761 DOI: 10.1074/jbc.r117.818237] [Citation(s) in RCA: 234] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A variety of mechanisms deliver cytosolic materials to the lysosomal compartment for degradation through autophagy. Here, we focus on two autophagic pathways, the chaperone-mediated autophagy and the endosomal microautophagy that rely on the cytosolic chaperone hsc70 for substrate targeting. Although hsc70 participates in the triage of proteins for degradation by different proteolytic systems, the common characteristic shared by these two forms of autophagy is that hsc70 binds directly to a specific five-amino acid motif in the cargo protein for its autophagic targeting. We summarize the current understanding of the molecular machineries behind each of these types of autophagy.
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Affiliation(s)
- Kumsal Tekirdag
- From the Department of Developmental and Molecular Biology, Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Ana Maria Cuervo
- From the Department of Developmental and Molecular Biology, Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, New York 10461
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14
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Macroautophagy and Chaperone-Mediated Autophagy in Heart Failure: The Known and the Unknown. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8602041. [PMID: 29576856 PMCID: PMC5822756 DOI: 10.1155/2018/8602041] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 11/22/2017] [Indexed: 02/04/2023]
Abstract
Cardiac diseases including hypertrophic and ischemic cardiomyopathies are increasingly being reported to accumulate misfolded proteins and damaged organelles. These findings have led to an increasing interest in protein degradation pathways, like autophagy, which are essential not only for normal protein turnover but also in the removal of misfolded and damaged proteins. Emerging evidence suggests a previously unprecedented role for autophagic processes in cardiac physiology and pathology. This review focuses on the major types of autophagic processes, the genes and protein complexes involved, and their regulation. It discusses the key similarities and differences between macroautophagy, chaperone-mediated autophagy, and selective mitophagy structures and functions. The genetic models available to study loss and gain of macroautophagy, mitophagy, and CMA are discussed. It defines the markers of autophagic processes, methods for measuring autophagic activities, and their interpretations. This review then summarizes the major studies of autophagy in the heart and their contribution to cardiac pathology. Some reports suggest macroautophagy imparts cardioprotection from heart failure pathology. Meanwhile, other studies find macroautophagy activation may be detrimental in cardiac pathology. An improved understanding of autophagic processes and their regulation may lead to a new genre of treatments for cardiac diseases.
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15
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Fernández-Fernández MR, Gragera M, Ochoa-Ibarrola L, Quintana-Gallardo L, Valpuesta JM. Hsp70 - a master regulator in protein degradation. FEBS Lett 2017; 591:2648-2660. [PMID: 28696498 DOI: 10.1002/1873-3468.12751] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 12/31/2022]
Abstract
Proteostasis, the controlled balance of protein synthesis, folding, assembly, trafficking and degradation, is a paramount necessity for cell homeostasis. Impaired proteostasis is a hallmark of ageing and of many human diseases. Molecular chaperones are essential for proteostasis in eukaryotic cells, and their function has traditionally been linked to protein folding, assembly and disaggregation. More recent findings suggest that chaperones also contribute to key steps in protein degradation. In particular, Hsp70 has an essential role in substrate degradation through the ubiquitin-proteasome system, as well as through different autophagy pathways. Accumulated knowledge suggests that the fate of an Hsp70 substrate is dictated by the combination of partners (cochaperones and other chaperones) that interact with Hsp70 in a given cell context.
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Affiliation(s)
| | - Marcos Gragera
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
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16
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Zhang J, Johnson JL, He J, Napolitano G, Ramadass M, Rocca C, Kiosses WB, Bucci C, Xin Q, Gavathiotis E, Cuervo AM, Cherqui S, Catz SD. Cystinosin, the small GTPase Rab11, and the Rab7 effector RILP regulate intracellular trafficking of the chaperone-mediated autophagy receptor LAMP2A. J Biol Chem 2017; 292:10328-10346. [PMID: 28465352 DOI: 10.1074/jbc.m116.764076] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 04/28/2017] [Indexed: 12/12/2022] Open
Abstract
The lysosomal storage disease cystinosis, caused by cystinosin deficiency, is characterized by cell malfunction, tissue failure, and progressive renal injury despite cystine-depletion therapies. Cystinosis is associated with defects in chaperone-mediated autophagy (CMA), but the molecular mechanisms are incompletely understood. Here, we show CMA substrate accumulation in cystinotic kidney proximal tubule cells. We also found mislocalization of the CMA lysosomal receptor LAMP2A and impaired substrate translocation into the lysosome caused by defective CMA in cystinosis. The impaired LAMP2A trafficking and localization were rescued either by the expression of wild-type cystinosin or by the disease-associated point mutant CTNS-K280R, which has no cystine transporter activity. Defective LAMP2A trafficking in cystinosis was found to associate with decreased expression of the small GTPase Rab11 and the Rab7 effector RILP. Defective Rab11 trafficking in cystinosis was rescued by treatment with small-molecule CMA activators. RILP expression was restored by up-regulation of the transcription factor EB (TFEB), which was down-regulated in cystinosis. Although LAMP2A expression is independent of TFEB, TFEB up-regulation corrected lysosome distribution and lysosomal LAMP2A localization in Ctns-/- cells but not Rab11 defects. The up-regulation of Rab11, Rab7, or RILP, but not its truncated form RILP-C33, rescued LAMP2A-defective trafficking in cystinosis, whereas dominant-negative Rab11 or Rab7 impaired LAMP2A trafficking. Treatment of cystinotic cells with a CMA activator increased LAMP2A localization at the lysosome and increased cell survival. Altogether, we show that LAMP2A trafficking is regulated by cystinosin, Rab11, and RILP and that CMA up-regulation is a potential clinically relevant mechanism to increase cell survival in cystinosis.
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Affiliation(s)
- Jinzhong Zhang
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Jennifer L Johnson
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Jing He
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Gennaro Napolitano
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Mahalakshmi Ramadass
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Celine Rocca
- the Department of Pediatrics, Division of Genetics, University of California, San Diego, La Jolla, California 92093-0734
| | - William B Kiosses
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Cecilia Bucci
- the Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Monteroni n. 165, 73100 Lecce, Italy, and
| | - Qisheng Xin
- the Departments of Biochemistry and.,Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | | | - Ana María Cuervo
- Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Stephanie Cherqui
- the Department of Pediatrics, Division of Genetics, University of California, San Diego, La Jolla, California 92093-0734
| | - Sergio D Catz
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037,
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17
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18
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Sala G, Marinig D, Arosio A, Ferrarese C. Role of Chaperone-Mediated Autophagy Dysfunctions in the Pathogenesis of Parkinson's Disease. Front Mol Neurosci 2016; 9:157. [PMID: 28066181 PMCID: PMC5179559 DOI: 10.3389/fnmol.2016.00157] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/08/2016] [Indexed: 12/20/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) represents a selective form of autophagy involved in the degradation of specific soluble proteins containing a pentapeptide motif that is recognized by a cytosolic chaperone able to deliver proteins to the lysosomes for degradation. Physiologically, CMA contributes to maintain crucial cellular functions including energetic balance and protein quality control. Dysfunctions in CMA have been associated to the pathogenesis of several neurodegenerative diseases characterized by accumulation and aggregation of proteins identified as CMA substrates. In particular, increasing evidence highlights the existence of a strong relationship between CMA defects and Parkinson’s disease (PD). Several mutations associated with familial forms of PD (SNCA, LRRK2, UCHL1 and DJ-1) have been demonstrated to block or reduce the activity of CMA, the main catabolic pathway for alpha-synuclein (asyn). CMA dysfunctions also leads to a mislocalization and inactivation of the transcription factor MEF2D that plays a key-role in the survival of dopaminergic neurons. Furthermore, reduced levels of CMA markers have been observed in post mortem brain samples from PD patients. The aim of this review article is to provide an organic revision of evidence for the involvement of CMA dysfunctions in the pathogenesis of PD. Updated findings obtained in patient’s specimens will be resumed, and results deriving from in vivo and in vitro studies will be discussed to evidence the current knowledge on the molecular mechanisms underlying CMA alterations in PD. Finally, the possibility of up-regulating CMA pathway as promising neuroprotective strategy will be considered.
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Affiliation(s)
- Gessica Sala
- Laboratory of Neurobiology, School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca Monza, Italy
| | - Daniele Marinig
- Laboratory of Neurobiology, School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-BicoccaMonza, Italy; PhD Program in Neuroscience, University of Milano-BicoccaMonza, Italy
| | - Alessandro Arosio
- Laboratory of Neurobiology, School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca Monza, Italy
| | - Carlo Ferrarese
- Laboratory of Neurobiology, School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-BicoccaMonza, Italy; Department of Neurology, San Gerardo Hospital, University of Milano-BicoccaMonza, Italy
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19
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Xilouri M, Stefanis L. Chaperone mediated autophagy in aging: Starve to prosper. Ageing Res Rev 2016; 32:13-21. [PMID: 27484893 DOI: 10.1016/j.arr.2016.07.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 06/07/2016] [Accepted: 07/04/2016] [Indexed: 10/21/2022]
Abstract
The major lysosomal proteolytic pathways essential for maintaining proper cellular homeostasis are macroautophagy, chaperone-mediated autophagy (CMA) and microautophagy. What differentiates CMA from the other types of autophagy is the fact that it does not involve vesicle formation; the unique feature of this pathway is the selective targeting of substrate proteins containing a CMA-targeting motif and the direct translocation into the lysosomal lumen, through the aid of chaperones/co-chaperones localized both at the cytosol and the lysosomes. CMA operates at basal conditions in most mammalian cell models analyzed so far, but it is mostly activated in response to stressors, such as trophic deprivation or oxidative stress. The activity of CMA has been shown to decline with age and such decline, correlating with accumulation of damaged/oxidized/aggregated proteins, may contribute to tissue dysfunction and, possibly, neurodegeneration. Herein, we review the recent knowledge regarding the molecular components, regulation and physiology of the CMA pathway, the contribution of impaired CMA activity to poor cellular homeostasis and inefficient response to stress during aging, and discuss the therapeutic opportunities offered by the restoration of CMA-dependent proteolysis in age-associated degenerative diseases.
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20
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Luks L, Sacchi S, Pollegioni L, Dietrich DR. Novel insights into renal D-amino acid oxidase accumulation: propiverine changes DAAO localization and peroxisomal size in vivo. Arch Toxicol 2016; 91:427-437. [PMID: 26961980 DOI: 10.1007/s00204-016-1685-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/22/2016] [Indexed: 11/29/2022]
Abstract
Chronic exposure to propiverine, a frequently prescribed pharmaceutical for treatment of overactive bladder and incontinence, provokes massive protein accumulation in the cytosol and nucleus of renal proximal tubule epithelial cells in rats. Previously, the accumulating protein was identified as D-amino acid oxidase (DAAO), a peroxisomal flavoenzyme expressed in kidney, liver and brain. The cellular mechanism of propiverine-induced DAAO accumulation, however, remains unexplained and poorly characterized. Therefore, to further increase the understanding of DAAO accumulation in rat kidney, this study aimed to characterize DAAO accumulations using differential immunofluorescent staining of rat kidney sections as well as in vitro binding analyses and proteasomal activity studies. We demonstrated that propiverine is neither a ligand of DAAO nor an inhibitor of the proteasome in vitro. However, propiverine treatment resulted in a significant decrease of peroxisomal size in rat proximal tubule epithelial cells. Moreover, peroxisomal catalase also accumulated in the cytosol and nuclei of propiverine-treated rats concurrently with DAAO. Taken together, our study indicates that propiverine treatment affects the trafficking and/or degradation of peroxisomal proteins such as DAAO and catalase by a so far unique and unknown mechanism.
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Affiliation(s)
- Lisanne Luks
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78457, Constance, Germany
| | - Silvia Sacchi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy.,The Protein Factory Research Center, Politecnico di Milano and University of Insubria, Milan, Varese, Italy
| | - Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy.,The Protein Factory Research Center, Politecnico di Milano and University of Insubria, Milan, Varese, Italy
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78457, Constance, Germany.
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21
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Shiba H, Yabu T, Sudayama M, Mano N, Arai N, Nakanishi T, Hosono K. Sequential steps of macroautophagy and chaperone-mediated autophagy are involved in the irreversible process of posterior silk gland histolysis during metamorphosis of Bombyx mori. ACTA ACUST UNITED AC 2016; 219:1146-53. [PMID: 26944491 DOI: 10.1242/jeb.130815] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 01/31/2016] [Indexed: 12/19/2022]
Abstract
To elucidate the degradation process of the posterior silk gland during metamorphosis of the silkworm ITALIC! Bombyx mori, tissues collected on the 6th day after entering the 5th instar (V6), prior to spinning (PS), during spinning (SP) and after cocoon formation (CO) were used to analyze macroautophagy, chaperone-mediated autophagy (CMA) and the adenosine triphosphate (ATP)-dependent ubiquitin proteasome. Immediately after entering metamorphosis stage PS, the levels of ATP and phosphorylated p70S6 kinase protein decreased spontaneously and continued to decline at SP, followed by a notable restoration at CO. In contrast, phosphorylated AMP-activated protein kinase α (AMPKα) showed increases at SP and CO. Most of the Atg8 protein was converted to form II at all stages. The levels of ubiquitinated proteins were high at SP and CO, and low at PS. The proteasome activity was high at V6 and PS but low at SP and CO. In the isolated lysosome fractions, levels of Hsc70/Hsp70 protein began to increase at PS and continued to rise at SP and CO. The lysosomal cathepsin B/L activity showed a dramatic increase at CO. Our results clearly demonstrate that macroautophagy occurs before entering the metamorphosis stage and strongly suggest that the CMA pathway may play an important role in the histolysis of the posterior silk gland during metamorphosis.
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Affiliation(s)
- Hajime Shiba
- Department of Applied Biological Science, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Takeshi Yabu
- Department of Applied Biological Science, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Makoto Sudayama
- Department of Applied Biological Science, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Nobuhiro Mano
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Naoto Arai
- Department of Applied Biological Science, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Teruyuki Nakanishi
- Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Kuniaki Hosono
- Department of Applied Biological Science, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
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22
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Patel B, Cuervo AM. Methods to study chaperone-mediated autophagy. Methods 2015; 75:133-40. [PMID: 25595300 PMCID: PMC4355229 DOI: 10.1016/j.ymeth.2015.01.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/30/2014] [Accepted: 01/06/2015] [Indexed: 12/25/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) is a multistep process that involves selective degradation and digestion of a pool of soluble cytosolic proteins in lysosomes. Cytosolic substrates are selectively identified and targeted by chaperones to lysosomes where they are subsequently translocated into the organelle lumen through a dedicated CMA-associated lysosomal membrane receptor/translocation complex. CMA contributes to maintaining a functional proteome, through elimination of altered proteins, and participates in the cellular energetic balance through amino acid recycling. Defective or dysfunctional CMA has been associated with human pathologies such as neurodegeneration, cancer, immunodeficiency or diabetes, increasing the overall interest in methods to monitor this selective autophagic pathway. Here, we describe approaches used to study CMA in different experimental models.
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Affiliation(s)
- Bindi Patel
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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23
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Xilouri M, Stefanis L. Chaperone mediated autophagy to the rescue: A new-fangled target for the treatment of neurodegenerative diseases. Mol Cell Neurosci 2015; 66:29-36. [PMID: 25724482 DOI: 10.1016/j.mcn.2015.01.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/14/2015] [Accepted: 01/24/2015] [Indexed: 12/28/2022] Open
Abstract
One of the main pathways of lysosomal proteolysis is chaperone-mediated autophagy (CMA), which represents a selective mechanism for the degradation of specific soluble proteins within lysosomes. Along with the other two lysosomal pathways, macro- and micro-autophagy, CMA contributes to cellular quality control through the removal of damaged or malfunctioning proteins. The two intrinsic characteristics of CMA are the selective targeting and the direct translocation of substrate proteins into the lysosomal lumen, in a fine-tuned manner through the orchestrated action of a chaperone/co-chaperone complex localized both at the cytosol and the lysosomes. Even though CMA was originally identified as a stress-induced pathway, basal CMA activity is detectable in most cell types analyzed so far, including neurons. Additionally, CMA activity declines with age and this may become a major aggravating factor contributing to neurodegeneration. More specifically, it has been suggested that CMA impairment may underlie the accumulation of misfolded/aggregated proteins, such as alpha-synuclein or LRRK2, whose levels or conformations are critical to Parkinson's disease pathogenesis. On the other hand, CMA induction might accelerate clearance of pathogenic proteins and promote cell survival, suggesting that CMA represents a viable therapeutic target for the treatment of various proteinopathies. In the current review, we provide an overview of the current state of knowledge regarding the role of CMA under physiological and pathological conditions of the nervous system and discuss the implications of these findings for therapeutic interventions for Parkinson's disease and other neurodegenerative disorders. This article is part of Special Issue entitled "Neuronal Protein".
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Affiliation(s)
- Maria Xilouri
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
| | - Leonidas Stefanis
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens, Athens, Greece; Second Department of Neurology, University of Athens Medical School, Athens, Greece
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24
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Bozaykut P, Ozer NK, Karademir B. Regulation of protein turnover by heat shock proteins. Free Radic Biol Med 2014; 77:195-209. [PMID: 25236750 DOI: 10.1016/j.freeradbiomed.2014.08.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 08/11/2014] [Accepted: 08/11/2014] [Indexed: 12/19/2022]
Abstract
Protein turnover reflects the balance between synthesis and degradation of proteins, and it is a crucial process for the maintenance of the cellular protein pool. The folding of proteins, refolding of misfolded proteins, and also degradation of misfolded and damaged proteins are involved in the protein quality control (PQC) system. Correct protein folding and degradation are controlled by many different factors, one of the most important of which is the heat shock protein family. Heat shock proteins (HSPs) are in the class of molecular chaperones, which may prevent the inappropriate interaction of proteins and induce correct folding. On the other hand, these proteins play significant roles in the degradation pathways, including endoplasmic reticulum-associated degradation (ERAD), the ubiquitin-proteasome system, and autophagy. This review focuses on the emerging role of HSPs in the regulation of protein turnover; the effects of HSPs on the degradation machineries ERAD, autophagy, and proteasome; as well as the role of posttranslational modifications in the PQC system.
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Affiliation(s)
- Perinur Bozaykut
- Genetic and Metabolic Diseases Research and Investigation Center, Department of Biochemistry, Faculty of Medicine, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Nesrin Kartal Ozer
- Genetic and Metabolic Diseases Research and Investigation Center, Department of Biochemistry, Faculty of Medicine, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Betul Karademir
- Genetic and Metabolic Diseases Research and Investigation Center, Department of Biochemistry, Faculty of Medicine, Marmara University, 34854 Maltepe, Istanbul, Turkey.
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25
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Schneider JL, Suh Y, Cuervo AM. Deficient chaperone-mediated autophagy in liver leads to metabolic dysregulation. Cell Metab 2014; 20:417-32. [PMID: 25043815 PMCID: PMC4156578 DOI: 10.1016/j.cmet.2014.06.009] [Citation(s) in RCA: 221] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 05/05/2014] [Accepted: 06/03/2014] [Indexed: 12/27/2022]
Abstract
The activity of chaperone-mediated autophagy (CMA), a catabolic pathway for selective degradation of cytosolic proteins in lysosomes, decreases with age, but the consequences of this functional decline in vivo remain unknown. In this work, we have generated a conditional knockout mouse to selectively block CMA in liver. We have found that blockage of CMA causes hepatic glycogen depletion and hepatosteatosis. The liver phenotype is accompanied by reduced peripheral adiposity, increased energy expenditure, and altered glucose homeostasis. Comparative lysosomal proteomics revealed that key enzymes in carbohydrate and lipid metabolism are normally degraded by CMA and that impairment of their regulated degradation contributes to the metabolic abnormalities observed in CMA-defective animals. These findings highlight the involvement of CMA in regulating hepatic metabolism and suggest that the age-related decline in CMA may have a negative impact on the energetic balance in old organisms.
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Affiliation(s)
- Jaime L Schneider
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yousin Suh
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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26
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Carrillo JC, Adenuga MD, Mckee RH. The sub-chronic toxicity of regular White Spirit in rats. Regul Toxicol Pharmacol 2014; 70:222-30. [PMID: 25013991 DOI: 10.1016/j.yrtph.2014.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/06/2014] [Indexed: 11/18/2022]
Abstract
Hydrocarbon solvents are mostly complex substances (UVCB) with carbon numbers in the range of approximately C5-C20. One of the most common types is a C9-C14 aliphatic solvent containing approximately 20% aromatics and commonly known as White Spirit in Europe and mineral spirits in the US. In previous repeated inhalation toxicity studies, White Spirit was reported to cause minimal systemic effects in most animal species with few effects other than male rat-specific kidney changes at levels up to approximately 2000mg/m(3). In the present study male and female rats were exposed to White Spirit vapors, 6h/day, 5days/week for 13weeks at levels of approximately 2000, 4000, or 8000mg/m(3) to assess the potential for effects at higher exposure levels. All of the rats survived the treatment period. In life observations were largely restricted to acute central nervous system (CNS) effects in the high exposure group. Terminal body weights of high exposure groups animals were significantly below control values. Statistically significant differences in the clinical and hematological observations were small and within normal physiological limits. Weights of some organs including liver, spleen and kidneys were elevated, but microscopic examination indicated that the only pathological effects were changes in the kidneys of the male rats, consistent with an α2u-globulin-mediated process, which is gender and species-specific and not relevant to humans. The overall no observed adverse effect level (NOAEC) was 4000mg/m(3).
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Affiliation(s)
- Juan-Carlos Carrillo
- Shell Health, Shell International B.V., P.O. Box 162, 2501 AN The Hague, The Netherlands.
| | - M David Adenuga
- ExxonMobil Biomedical Sciences, Inc., 1545 Route 22 E., Annandale, NJ 08801, USA
| | - Richard H Mckee
- ExxonMobil Biomedical Sciences, Inc., 1545 Route 22 E., Annandale, NJ 08801, USA
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27
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Abstract
Far from now are the days when investigators raced to identify the proteolytic system responsible for the degradation of their favorite protein. Nowadays, it is well accepted that a given protein can be degraded by different systems depending on factors such as cell type, cellular conditions, or functionality of each proteolytic pathway. The realization of this sharing of substrates among pathways has also helped to unveil deeper levels of communication among the different proteolytic systems. Thus, cells often respond to blockage of one degradative mechanism by upregulating any of the other available pathways. In addition, effectors and regulators of one proteolytic system can be degraded by a different proteolytic pathway that exerts, in this way, a regulatory function. In this mini review, we describe the different levels of cross-talk among autophagic pathways and the ubiquitin/proteasome system. We also provide examples of how this proteolytic communication is used for compensatory purposes in different pathological conditions and discuss the possible therapeutic potential of targeting the modulators of the cross-talk among proteolytic pathways.
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Affiliation(s)
- Caroline Park
- Department of Developmental and Molecular Biology, Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA
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28
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Abstract
SIGNIFICANCE Autophagy is a highly conserved eukaryotic cellular recycling process. Through the degradation of cytoplasmic organelles, proteins, and macromolecules, and the recycling of the breakdown products, autophagy plays important roles in cell survival and maintenance. Accordingly, dysfunction of this process contributes to the pathologies of many human diseases. RECENT ADVANCES Extensive research is currently being done to better understand the process of autophagy. In this review, we describe current knowledge of the morphology, molecular mechanism, and regulation of mammalian autophagy. CRITICAL ISSUES At the mechanistic and regulatory levels, there are still many unanswered questions and points of confusion that have yet to be resolved. FUTURE DIRECTIONS Through further research, a more complete and accurate picture of the molecular mechanism and regulation of autophagy will not only strengthen our understanding of this significant cellular process, but will aid in the development of new treatments for human diseases in which autophagy is not functioning properly.
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Affiliation(s)
- Katherine R Parzych
- Department of Molecular, Cellular and Developmental Biology, Life Sciences Institute, University of Michigan , Ann Arbor, Michigan
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29
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The sub-chronic toxicity in rats of isoparaffinic solvents. Regul Toxicol Pharmacol 2013; 67:446-55. [DOI: 10.1016/j.yrtph.2013.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 02/03/2023]
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30
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Abstract
Chaperone-mediated autophagy (CMA) is a lysosomal proteolytic pathway in which cytosolic substrate proteins contain specific chaperone recognition sequences required for degradation and are translocated directly across the lysosomal membrane for destruction. CMA proteolytic activity has a reciprocal relationship with macroautophagy: CMA is most active in cells in which macroautophagy is least active. Normal renal proximal tubular cells have low levels of macroautophagy, but high basal levels of CMA activity. CMA activity is regulated by starvation, growth factors, oxidative stress, lipids, aging, and retinoic acid signaling. The physiological consequences of changes in CMA activity depend on the substrate proteins present in a given cell type. In the proximal tubule, increased CMA results from protein or calorie starvation and from oxidative stress. Overactivity of CMA can be associated with tubular lysosomal pathology and certain cancers. Reduced CMA activity contributes to protein accumulation in renal tubular hypertrophy, but may contribute to oxidative tissue damage in diabetes and aging. Although there are more questions than answers about the role of high basal CMA activity, this remarkable feature of tubular protein metabolism appears to influence a variety of chronic diseases.
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Affiliation(s)
- Harold A Franch
- Research Service, Atlanta Veterans Affairs Medical Center, Decatur, GA; and Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA.
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31
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Hai A, Kizilbash NA. α(2)-µ-Globulin fragment (a2-f) from kidneys of male rats. Bioinformation 2013; 9:145-9. [PMID: 23422892 PMCID: PMC3569602 DOI: 10.6026/97320630009145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 01/11/2013] [Indexed: 11/23/2022] Open
Abstract
The structure of α2-µ-Globulin fragment (A2-f) is not known.α2-µ-Globulin fragment (A2-f) is a 15.5 kDa protein that binds
equimolar amount of fatty acids in male rat kidneys. The expression of this protein has been shown to change in response to druginduced
and genetic hypertension which suggests that it plays an important role in renal fatty acid metabolism under pathological
conditions as well as normal conditions. A2-f has sequence homology with amino acid 28-178 of α2-µ-Globulin (A2U) that is
synthesized pre-dominantly in the male rat liver and is present in the urine. It is believed that unusual structural features permit
A2-f to be targeted to the proximal tubule cell; to escape lysosomal degradation in liver and to enter the cytosol of proximal tubule
cells of the kidneys. Homology modeling has been employed to determine the structural elements of this protein and they have
been compared with the published structure of A2U. Results suggest differences between the structure of A2-f and its precursor
protein A2U.
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Affiliation(s)
- Abdul Hai
- Department of Biochemistry, Faculty of Medicine, Northern Border University, Arar-91431, Saudi Arabia
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32
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Abstract
Cells continuously turn over proteins through cycles of synthesis and degradation in order to maintain a functional proteome and to exert a tight control in the levels of regulatory proteins. Selective degradation of proteins was initially thought to be an exclusive function of the ubiquitin-proteasome system, however, over the years, the contribution of lysosomes to this selective degradation, through the process of autophagy, has become consolidated. In this context, molecular chaperones, classically associated with protein folding, unfolding and assembling have been revealed as important modulators of selectivity during the autophagic process. Here, we review this relatively new role of chaperones in mediating selective autophagy and comment on how alterations of this function can lead to human pathologies associated to proteotoxicity.
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Affiliation(s)
- Susmita Kaushik
- Department of Developmental and Molecular Biology, Institute for Aging Studies, Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, NY, USA.
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33
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Abstract
Autophagy is a self-digesting mechanism responsible for removal of damaged organelles, malformed proteins during biosynthesis, and nonfunctional long-lived proteins by lysosome. Autophagy has been divided into three general types depending on the mechanism by which intracellular materials are delivered into lysosome for degradation that is, microautophagy, chaperone-mediated autophagy (CMA), and macroautophagy. In microautophagy cytoplasm material is sequestered through direct invagination to the lysosomal membrane. Whereas in CMA proteins flagged with pentapeptide motif (KFERQ) were selectively degraded through direct translocation into lysosome. Macroautophagy involves the formation of subcellular double-membrane-bound structures called autophagosomes that contain degradable contents of cytoplasm materials and deliver them into lysosomes for breakdown by lysosomal enzymes. The molecular mechanism of autophagy involves several conserved Atg (autophagy-related) proteins. Systems produce modified complexes Atg8-PE and Atg5-Atg12-Atg16 as autophagy regulators. Autophagy is activated in response to diverse stress and physiological conditions. For example, food deprivation, hyperthermia, and hypoxia are mediated by factors like insulin/IGF-1, m-TOR signaling, FOXO transcription factors, and chaperones. The perturbance in autophagy may lead to several types of cancers, myopathies, and neuromuscular disorders. Several autophagy inducers and inhibitors like 3-methyladenine (3-MA), bafilomycin A1, LY294002 (LY), and Velcade have been used to treat disease is an intense field of study.
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Affiliation(s)
- Mallikarjun Badadani
- Department of Pediatrics, University of California at Irvine, 2501 Hewitt Hall, Irvine, CA 92697, USA
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34
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Comprehensive review on the HSC70 functions, interactions with related molecules and involvement in clinical diseases and therapeutic potential. Pharmacol Ther 2012; 136:354-74. [PMID: 22960394 DOI: 10.1016/j.pharmthera.2012.08.014] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 08/14/2012] [Indexed: 12/28/2022]
Abstract
Heat shock cognate protein 70 (HSC70) is a constitutively expressed molecular chaperone which belongs to the heat shock protein 70 (HSP70) family. HSC70 shares some of the structural and functional similarity with HSP70. HSC70 also has different properties compared with HSP70 and other heat shock family members. HSC70 performs its full functions by the cooperation of co-chaperones. It interacts with many other molecules as well and regulates various cellular functions. It is also involved in various diseases and may become a biomarker for diagnosis and potential therapeutic targets for design, discovery, and development of novel drugs to treat various diseases. In this article, we provide a comprehensive review on HSC70 from the literatures including the basic general information such as classification, structure and cellular location, genetics and function, as well as its protein association and interaction with other proteins. In addition, we also discussed the relationship of HSC70 and related clinical diseases such as cancer, cardiovascular, neurological, hepatic and many other diseases and possible therapeutic potential and highlight the progress and prospects of research in this field. Understanding the functions of HSC70 and its interaction with other molecules will help us to reveal other novel properties of this protein. Scientists may be able to utilize this protein as a biomarker and therapeutic target to make significant advancement in scientific research and clinical setting in the future.
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35
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Huber TB, Edelstein CL, Hartleben B, Inoki K, Jiang M, Koya D, Kume S, Lieberthal W, Pallet N, Quiroga A, Ravichandran K, Susztak K, Yoshida S, Dong Z. Emerging role of autophagy in kidney function, diseases and aging. Autophagy 2012; 8:1009-31. [PMID: 22692002 PMCID: PMC3429540 DOI: 10.4161/auto.19821] [Citation(s) in RCA: 207] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 02/24/2012] [Accepted: 02/27/2012] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a highly conserved process that degrades cellular long-lived proteins and organelles. Accumulating evidence indicates that autophagy plays a critical role in kidney maintenance, diseases and aging. Ischemic, toxic, immunological, and oxidative insults can cause an induction of autophagy in renal epithelial cells modifying the course of various kidney diseases. This review summarizes recent insights on the role of autophagy in kidney physiology and diseases alluding to possible novel intervention strategies for treating specific kidney disorders by modifying autophagy.
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Affiliation(s)
- Tobias B Huber
- Renal Division, University Hospital Freiburg; Freiburg, Germany.
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36
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Kaushik S, Cuervo AM. Chaperone-mediated autophagy: a unique way to enter the lysosome world. Trends Cell Biol 2012; 22:407-17. [PMID: 22748206 DOI: 10.1016/j.tcb.2012.05.006] [Citation(s) in RCA: 595] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 05/27/2012] [Accepted: 05/29/2012] [Indexed: 01/13/2023]
Abstract
All cellular proteins undergo continuous synthesis and degradation. This permanent renewal is necessary to maintain a functional proteome and to allow rapid changes in levels of specific proteins with regulatory purposes. Although for a long time lysosomes were considered unable to contribute to the selective degradation of individual proteins, the discovery of chaperone-mediated autophagy (CMA) changed this notion. Here, we review the characteristics that set CMA apart from other types of lysosomal degradation and the subset of molecules that confer cells the capability to identify individual cytosolic proteins and direct them across the lysosomal membrane for degradation.
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Affiliation(s)
- Susmita Kaushik
- Department of Developmental and Molecular Biology, Institute for Aging Studies, Marion Bessin Liver Research Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Chanin Building 504, Bronx, NY 10461, USA
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37
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Malkus KA, Ischiropoulos H. Regional deficiencies in chaperone-mediated autophagy underlie α-synuclein aggregation and neurodegeneration. Neurobiol Dis 2012; 46:732-44. [PMID: 22426402 DOI: 10.1016/j.nbd.2012.03.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 01/27/2012] [Accepted: 03/01/2012] [Indexed: 01/13/2023] Open
Abstract
In neurodegenerative diseases, it remains unclear why certain brain regions are selectively vulnerable to protein aggregation. In transgenic mice expressing human A53T α-synuclein, the brainstem and spinal cord develop the most prominent α-synuclein inclusions which correlate with age-dependent motor dysfunction. Herein we present the novel finding that this selective aggregation is in part dependent on the inability of chaperone-mediated autophagy (CMA) to effectively degrade α-synuclein in these brain regions. Lysosomal assays revealed that CMA activity was significantly decreased in aggregation-prone regions compared to the remainder of the brain. Previously, CMA activity has been shown to be proportional to levels of the CMA receptor Lamp-2a. Using antibodies, brain tissue from Lamp-2a null mice, enzymatic deglycosylation, and mass spectrometry, we identified Lamp2a as a novel 72kDa glycoprotein in the mouse brain. Examination of Lamp-2a levels revealed differences in expression across brain regions. The brainstem and the spinal cord had a more than three-fold greater levels of Lamp-2a as compared to regions less vulnerable to aggregation and exhibited a selective upregulation of Lamp-2a during development of α-synuclein inclusions. Despite this dynamic response of Lamp-2a, the levels of substrates bound to the brain lysosomes as well as the rates of substrate uptake and degradation were not proportional to the levels of Lamp-2a. These regional differences in CMA activity and Lamp-2a expression were found in both non-transgenic mice as well as A53T α-syn mice. Therefore, these are inherent variations and not a transgene-specific effect. However, differences in CMA activity may render select brain regions vulnerable to homeostatic dysfunction in the presence of stressors such as overexpression of human A53T α-syn. Collectively, the data provide a potential mechanism to explain the dichotomy of vulnerability or resistance that underlies brain regions during aggregate formation in neurodegenerative disease.
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Affiliation(s)
- Kristen A Malkus
- Departments of Pediatrics and Pharmacology, The Children's Hospital of Philadelphia Research Institute and The Perelman School of Medicine at the University of Pennsylvania Philadelphia, Pennsylvania 19104-4318, USA
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38
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Abstract
Cytosolic proteins can be selectively delivered to lysosomes for degradation through a type of autophagy known as chaperone-mediated autophagy (CMA). CMA contributes to intracellular quality control and to the cellular response to stress. Compromised CMA has been described in aging and in different age-related disorders. CMA substrates cross the lysosomal membrane through a translocation complex; consequently, changes in the properties of the lysosomal membrane should have a marked impact on CMA activity. In this work, we have analyzed the impact that dietary intake of lipids has on CMA activity. We have found that chronic exposure to a high-fat diet or acute exposure to a cholesterol-enriched diet both have an inhibitory effect on CMA. Lysosomes from livers of lipid-challenged mice had a marked decrease in the levels of the CMA receptor, the lysosome-associated membrane protein type 2A, because of loss of its stability at the lysosomal membrane. This accelerated degradation of lysosome-associated membrane protein type 2A, also described as the mechanism that determines the decline in CMA activity with age, results from its increased mobilization to specific lipid regions at the lysosomal membrane. Comparative lipidomic analyses revealed qualitative and quantitative changes in the lipid composition of the lysosomal membrane of the lipid-challenged animals that resemble those observed with age. Our findings identify a previously unknown negative impact of high dietary lipid intake on CMA and underscore the importance of diet composition on CMA malfunction in aging.
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39
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Shi R, Weng J, Szelemej P, Kong J. Caspase-Independent Stroke Targets. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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40
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Cuervo AM. Chaperone-mediated autophagy: Dice's 'wild' idea about lysosomal selectivity. Nat Rev Mol Cell Biol 2011; 12:535-41. [PMID: 21750569 DOI: 10.1038/nrm3150] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A little over 1 year ago, we lost a bright scientist and a dear colleague who, in his younger years, proposed the 'heretical' idea that lysosomes could selectively degrade cytosolic proteins. That scientist was J. Fred Dice, and his lifetime's discovery was the degradative pathway that we now know as chaperone-mediated autophagy.
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Affiliation(s)
- Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Marion Bessin Liver Research Center and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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41
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Koga H, Martinez-Vicente M, Macian F, Verkhusha VV, Cuervo AM. A photoconvertible fluorescent reporter to track chaperone-mediated autophagy. Nat Commun 2011; 2:386. [PMID: 21750540 PMCID: PMC3529934 DOI: 10.1038/ncomms1393] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 06/15/2011] [Indexed: 11/22/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) is a selective mechanism for the degradation of soluble proteins in lysosomes. CMA contributes to cellular quality control and is activated as part of the cellular response to different stressors. Defective CMA has been identified in aging and different age-related diseases. Until now, CMA activity could only be measured in vitro upon isolation of lysosomes. Here we report the development of a photoconvertible fluorescent reporter that allows monitoring of CMA activity in living cells. Activation of CMA increases the association of the reporter with lysosomes which are visualized as a change in the intracellular fluorescence. The CMA reporter can be utilized in a broad variety of cells and is suitable for high-content microscopy. Using this reporter, we find that levels of basal and inducible CMA activity are cell-type dependent and we have identified an upregulation of this pathway in response to the catalytic inhibition of the proteasome.
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Affiliation(s)
- Hiroshi Koga
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA
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42
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Koga H, Cuervo AM. Chaperone-mediated autophagy dysfunction in the pathogenesis of neurodegeneration. Neurobiol Dis 2011; 43:29-37. [PMID: 20643207 PMCID: PMC2998583 DOI: 10.1016/j.nbd.2010.07.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 07/02/2010] [Accepted: 07/09/2010] [Indexed: 10/19/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) contributes to selective degradation of individual soluble proteins in lysosomes. Unique to this type of autophagy is the fact that proteins reach the lysosomal lumen for degradation by directly crossing the lysosomal membrane, in contrast with the vesicle-mediated delivery characteristic of the other types of autophagy. These two characteristics--selective targeting and direct translocation of substrates--determine the contribution of CMA to different physiological functions and the type of pathological conditions associated with CMA dysfunction. In this review, we briefly revise recent findings on the molecular mechanisms behind CMA function, and describe the physiological relevance of the selective lysosomal degradation through this pathway. We also comment on the cellular consequences of CMA malfunction and on the connections already established between CMA dysfunction and different human disorders, with special emphasis on neurodegenerative diseases. This article is part of a Special Issue entitled "Autophagy and protein degradation in neurological diseases."
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Affiliation(s)
- Hiroshi Koga
- Department of Developmental and Molecular Biology, Institute for Aging Research, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, USA.
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43
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Kaushik S, Bandyopadhyay U, Sridhar S, Kiffin R, Martinez-Vicente M, Kon M, Orenstein SJ, Wong E, Cuervo AM. Chaperone-mediated autophagy at a glance. J Cell Sci 2011; 124:495-9. [PMID: 21282471 DOI: 10.1242/jcs.073874] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Susmita Kaushik
- Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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44
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Kaminskyy V, Zhivotovsky B. Proteases in autophagy. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1824:44-50. [PMID: 21640203 DOI: 10.1016/j.bbapap.2011.05.013] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 05/13/2011] [Accepted: 05/16/2011] [Indexed: 02/07/2023]
Abstract
Autophagy is a process involved in the proteolytic degradation of cellular macromolecules in lysosomes, which requires the activity of proteases, enzymes that hydrolyse peptide bonds and play a critical role in the initiation and execution of autophagy. Importantly, proteases also inhibit autophagy in certain cases. The initial steps of macroautophagy depend on the proteolytic processing of a particular protein, Atg8, by a cysteine protease, Atg4. This processing step is essential for conjugation of Atg8 with phosphatidylethanolamine and, subsequently, autophagosome formation. Lysosomal hydrolases, known as cathepsins, can be divided into several groups based on the catalitic residue in the active site, namely, cysteine, serine and aspartic cathepsins, which catalyse the cleavage of peptide bonds of autophagy substrates and, together with other factors, dispose of the autophagic flux. Whilst most cathepsins degrade autophagosomal content, some, such as cathepsin L, also degrade lysosomal membrane components, GABARAP-II and LC3-II. In contrast, cathepsin A, a serine protease, is involved in inhibition of chaperon-mediated autophagy through proteolytic processing of LAMP-2A. In addition, other families of calcium-dependent non-lysosomal cysteine proteases, such as calpains, and cysteine aspartate-specific proteases, such as caspases, may cleave autophagy-related proteins, negatively influencing the execution of autophagic processes. Here we discuss the current state of knowledge concerning protein degradation by autophagy and outline the role of proteases in autophagic processes. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.
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Affiliation(s)
- Vitaliy Kaminskyy
- Institute of Environmental Medicine, Division of Toxicology, Karolinska Instituet, Stockholm, Sweden
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45
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Hubbard VM, Valdor R, Macian F, Cuervo AM. Selective autophagy in the maintenance of cellular homeostasis in aging organisms. Biogerontology 2011; 13:21-35. [PMID: 21461872 DOI: 10.1007/s10522-011-9331-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 03/18/2011] [Indexed: 12/15/2022]
Abstract
Altered cellular homeostasis, accumulation of damaged non-functional organelles and presence of protein inclusions are characteristics shared by almost all types of differentiated cells in aged organisms. Cells rely on quality control mechanisms to prevent the occurrence of these events and the subsequent cellular compromise associated with them. What goes wrong in aging cells? Growing evidence supports gradual malfunctioning with age of the cellular quality control systems. In this review, we focus on autophagy, a catabolic process that contributes to the maintenance of cellular homeostasis through the degradation of unwanted and damaged components in lysosomes. We describe recent advances on the molecular characterization of this process, its different variants and the multiplicity of functions attributed to them. Autophagic dysfunction has been identified in severe human disorders, many of which worsen with age. We comment on the contribution of an adequate autophagic function to longevity, and the negative impact on health-span of the age-dependent decline in autophagic function.
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Affiliation(s)
- Vanessa M Hubbard
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA
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46
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Koga H, Kaushik S, Cuervo AM. Protein homeostasis and aging: The importance of exquisite quality control. Ageing Res Rev 2011; 10:205-15. [PMID: 20152936 DOI: 10.1016/j.arr.2010.02.001] [Citation(s) in RCA: 305] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 01/25/2010] [Accepted: 02/01/2010] [Indexed: 01/12/2023]
Abstract
All cells count on precise mechanisms that regulate protein homeostasis to maintain a stable and functional proteome. A progressive deterioration in the ability of cells to preserve the stability of their proteome occurs with age and contributes to the functional loss characteristic of old organisms. Molecular chaperones and the proteolytic systems are responsible for this cellular quality control by assuring continuous renewal of intracellular proteins. When protein damage occurs, such as during cellular stress, the coordinated action of these cellular surveillance systems allows detection and repair of the damaged structures or, in many instances, leads to the complete elimination of the altered proteins from inside cells. Dysfunction of the quality control mechanisms and intracellular accumulation of abnormal proteins in the form of protein inclusions and aggregates occur in almost all tissues of an aged organism. Preservation or enhancement of the activity of these surveillance systems until late in life improves their resistance to stress and is sufficient to slow down aging. In this work, we review recent advances on our understanding of the contribution of chaperones and proteolytic systems to the maintenance of cellular homeostasis, the cellular response to stress and ultimately to longevity.
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Affiliation(s)
- Hiroshi Koga
- Department of Developmental and Molecular Biology, Marion Bessin Liver Research Center, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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47
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Li W, Yang Q, Mao Z. Chaperone-mediated autophagy: machinery, regulation and biological consequences. Cell Mol Life Sci 2011; 68:749-63. [PMID: 20976518 PMCID: PMC11114861 DOI: 10.1007/s00018-010-0565-6] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 10/07/2010] [Accepted: 10/08/2010] [Indexed: 10/18/2022]
Abstract
Degradation of dysfunctional intracellular components in the lysosome system can occur through three different pathways, i.e., macroautophagy, microautophagy and chaperone-mediated autophagy (CMA). In this review, we focus on CMA, a type of autophagy distinct from the other two autophagic pathways owing to its selectivity, saturability and competitivity by which a subset of long-lived cytosolic soluble proteins are directly delivered into the lysosomal lumen via specific receptors. CMA participates in quality control to maintain normal cell functions by clearing "old" proteins and provides energy to cells under nutritional stress. Deregulation of CMA has recently been shown to underlie some diseases, especially neurodegenerative disorders for which the decline with age in the activity of CMA may become a major aggravating factor. Therefore, targeting aberrant alteration in CMA under pathological conditions could serve as a potential therapeutic strategy for treating related diseases.
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Affiliation(s)
- Wenming Li
- Departments of Pharmacology and Neurology, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Qian Yang
- Departments of Pharmacology and Neurology, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Zixu Mao
- Departments of Pharmacology and Neurology, Emory University School of Medicine, Atlanta, GA 30322 USA
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48
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Yabu T, Imamura S, Mohammed MS, Touhata K, Minami T, Terayama M, Yamashita M. Differential gene expression of HSC70/HSP70 in yellowtail cells in response to chaperone-mediated autophagy. FEBS J 2011; 278:673-85. [DOI: 10.1111/j.1742-4658.2010.07989.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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49
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Arias E, Cuervo AM. Chaperone-mediated autophagy in protein quality control. Curr Opin Cell Biol 2010; 23:184-9. [PMID: 21094035 DOI: 10.1016/j.ceb.2010.10.009] [Citation(s) in RCA: 222] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 10/01/2010] [Accepted: 10/21/2010] [Indexed: 10/18/2022]
Abstract
Chaperone-mediated autophagy is a selective mechanism for degradation of soluble cytosolic proteins in lysosomes that distinguishes itself from other autophagic pathways by the selectivity with which CMA substrates are targeted for degradation. The recent molecular dissection of this autophagic pathway and the development of experimental models with compromised CMA have unveiled the important contribution of this pathway to protein quality control. In fact, CMA activation seems to be a common mechanism of cellular defense against proteotoxicity.
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Affiliation(s)
- Esperanza Arias
- Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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50
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Orenstein SJ, Cuervo AM. Chaperone-mediated autophagy: molecular mechanisms and physiological relevance. Semin Cell Dev Biol 2010; 21:719-26. [PMID: 20176123 PMCID: PMC2914824 DOI: 10.1016/j.semcdb.2010.02.005] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 02/07/2010] [Accepted: 02/15/2010] [Indexed: 11/18/2022]
Abstract
Chaperone-mediated autophagy (CMA) is a selective lysosomal pathway for the degradation of cytosolic proteins. We review in this work some of the recent findings on this pathway regarding the molecular mechanisms that contribute to substrate targeting, binding and translocation across the lysosomal membrane. We have placed particular emphasis on the critical role that changes in the lipid composition of the lysosomal membrane play in the regulation of CMA, as well as the modulatory effect of other novel CMA components. In the second part of this review, we describe the physiological relevance of CMA and its role as one of the cellular mechanisms involved in the response to stress. Changes with age in CMA activity and the contribution of failure of CMA to the phenotype of aging and to the pathogenesis of several age-related pathologies are also described.
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Affiliation(s)
- Samantha J. Orenstein
- Department of Developmental and Molecular Biology, Marion Bessin Liver Research Center, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA, 10461
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Marion Bessin Liver Research Center, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA, 10461
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