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Holmannova D, Borsky P, Parova H, Stverakova T, Vosmik M, Hruska L, Fiala Z, Borska L. Non-Genomic Hallmarks of Aging-The Review. Int J Mol Sci 2023; 24:15468. [PMID: 37895144 PMCID: PMC10607657 DOI: 10.3390/ijms242015468] [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: 10/08/2023] [Revised: 10/19/2023] [Accepted: 10/21/2023] [Indexed: 10/29/2023] Open
Abstract
Aging is a natural, gradual, and inevitable process associated with a series of changes at the molecular, cellular, and tissue levels that can lead to an increased risk of many diseases, including cancer. The most significant changes at the genomic level (DNA damage, telomere shortening, epigenetic changes) and non-genomic changes are referred to as hallmarks of aging. The hallmarks of aging and cancer are intertwined. Many studies have focused on genomic hallmarks, but non-genomic hallmarks are also important and may additionally cause genomic damage and increase the expression of genomic hallmarks. Understanding the non-genomic hallmarks of aging and cancer, and how they are intertwined, may lead to the development of approaches that could influence these hallmarks and thus function not only to slow aging but also to prevent cancer. In this review, we focus on non-genomic changes. We discuss cell senescence, disruption of proteostasis, deregualation of nutrient sensing, dysregulation of immune system function, intercellular communication, mitochondrial dysfunction, stem cell exhaustion and dysbiosis.
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Affiliation(s)
- Drahomira Holmannova
- Institute of Preventive Medicine, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (D.H.); (Z.F.); (L.B.)
| | - Pavel Borsky
- Institute of Preventive Medicine, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (D.H.); (Z.F.); (L.B.)
| | - Helena Parova
- Department of Clinical Biochemistry and Diagnostics, University Hospital, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (H.P.); (T.S.)
| | - Tereza Stverakova
- Department of Clinical Biochemistry and Diagnostics, University Hospital, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (H.P.); (T.S.)
| | - Milan Vosmik
- Department of Oncology and Radiotherapy, University Hospital, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (M.V.); (L.H.)
| | - Libor Hruska
- Department of Oncology and Radiotherapy, University Hospital, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (M.V.); (L.H.)
| | - Zdenek Fiala
- Institute of Preventive Medicine, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (D.H.); (Z.F.); (L.B.)
| | - Lenka Borska
- Institute of Preventive Medicine, Faculty of Medicine in Hradec Kralove, Charles University, 500 03 Hradec Kralove, Czech Republic; (D.H.); (Z.F.); (L.B.)
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Choi YJ, Yun SH, Yu J, Mun Y, Lee W, Park CJ, Han BW, Lee BH. Chaperone-mediated autophagy dysregulation during aging impairs hepatic fatty acid oxidation via accumulation of NCoR1. Mol Metab 2023; 76:101784. [PMID: 37524243 PMCID: PMC10448198 DOI: 10.1016/j.molmet.2023.101784] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/21/2023] [Accepted: 07/27/2023] [Indexed: 08/02/2023] Open
Abstract
OBJECTIVE Alterations in lipid metabolism are associated with aging and age-related diseases. Chaperone-mediated autophagy (CMA) is a lysosome-dependent process involved in specific protein degradation. Heat shock cognate 71 kDa protein (Hsc70) recognizes cytosolic proteins with KFERQ motif and allows them to enter the lysosome via lysosome-associated membrane glycoprotein 2 isoform A (LAMP2A). CMA deficiency is associated with dysregulated lipid metabolism in the liver. In this study, we examined the effect of CMA on lipid metabolism in the aged liver. METHODS 12-week-old and 88-week-old mice were employed to assess the effect of aging on hepatic CMA activity. We generated CMA-deficient mouse primary hepatocytes using siRNA for Lamp2a and liver-specific LAMP2A knockdown mice via adeno-associated viruses expressing short hairpin RNAs to investigate the influence of CMA on lipid metabolism. RESULTS We noted aging-induced progression toward fatty liver and a decrease in LAMP2A levels in total protein and lysosomes. The expression of genes associated with fatty acid oxidation was markedly downregulated in the aged liver, as verified in CMA-deficient mouse primary hepatocytes. In addition, the aged liver accumulated nuclear receptor corepressor 1 (NCoR1), a negative regulator of peroxisome proliferator-activated receptor α (PPARα). We found that Hsc70 binds to NCoR1 via the KFERQ motif. Lamp2a siRNA treatment accumulated NCoR1 and decreased the fatty acid oxidation rate. Pharmacological activation of CMA by AR7 treatment increased LAMP2A expression, leading to NCoR1 degradation. A liver-specific LAMP2A knockdown via adeno-associated viruses expressing short hairpin RNAs caused NCoR1 accumulation, inactivated PPARα, downregulated the expression of fatty acid oxidation-related genes and significantly increased liver triglyceride levels. CONCLUSIONS Our results elucidated a novel PPARα regulatory mechanism involving CMA-mediated NCoR1 degradation during aging. These findings demonstrate that CMA dysregulation is crucial for the progression of aging-related fatty liver diseases.
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Affiliation(s)
- You-Jin Choi
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Sung Ho Yun
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jihyeon Yu
- Division of Life Science, Korea Polar Research Institute, Incheon 21990, Republic of Korea
| | - Yewon Mun
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Wonseok Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Cheon Jun Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Byung Woo Han
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Byung-Hoon Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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Fernandes SA, Demetriades C. The Multifaceted Role of Nutrient Sensing and mTORC1 Signaling in Physiology and Aging. FRONTIERS IN AGING 2021; 2:707372. [PMID: 35822019 PMCID: PMC9261424 DOI: 10.3389/fragi.2021.707372] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 08/12/2021] [Indexed: 01/10/2023]
Abstract
The mechanistic Target of Rapamycin (mTOR) is a growth-related kinase that, in the context of the mTOR complex 1 (mTORC1), touches upon most fundamental cellular processes. Consequently, its activity is a critical determinant for cellular and organismal physiology, while its dysregulation is commonly linked to human aging and age-related disease. Presumably the most important stimulus that regulates mTORC1 activity is nutrient sufficiency, whereby amino acids play a predominant role. In fact, mTORC1 functions as a molecular sensor for amino acids, linking the cellular demand to the nutritional supply. Notably, dietary restriction (DR), a nutritional regimen that has been shown to extend lifespan and improve healthspan in a broad spectrum of organisms, works via limiting nutrient uptake and changes in mTORC1 activity. Furthermore, pharmacological inhibition of mTORC1, using rapamycin or its analogs (rapalogs), can mimic the pro-longevity effects of DR. Conversely, nutritional amino acid overload has been tightly linked to aging and diseases, such as cancer, type 2 diabetes and obesity. Similar effects can also be recapitulated by mutations in upstream mTORC1 regulators, thus establishing a tight connection between mTORC1 signaling and aging. Although the role of growth factor signaling upstream of mTORC1 in aging has been investigated extensively, the involvement of signaling components participating in the nutrient sensing branch is less well understood. In this review, we provide a comprehensive overview of the molecular and cellular mechanisms that signal nutrient availability to mTORC1, and summarize the role that nutrients, nutrient sensors, and other components of the nutrient sensing machinery play in cellular and organismal aging.
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Affiliation(s)
- Stephanie A. Fernandes
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- *Correspondence: Constantinos Demetriades,
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Sakai M, Ohnishi K, Masuda M, Ohminami H, Yamanaka-Okumura H, Hara T, Taketani Y. Isorhamnetin, a 3'-methoxylated flavonol, enhances the lysosomal proteolysis in J774.1 murine macrophages in a TFEB-independent manner. Biosci Biotechnol Biochem 2020; 84:1221-1231. [PMID: 32046625 DOI: 10.1080/09168451.2020.1727309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/04/2020] [Indexed: 10/25/2022]
Abstract
Lysosome is the principal organelle for the ultimate degradation of cellular macromolecules, which are delivered through endocytosis, phagocytosis, and autophagy. The lysosomal functions have been found to be impaired by fatty foods and aging, and more importantly, the lysosomal dysfunction in macrophages has been reported as a risk of atherosclerosis development. In this study, we searched for dietary polyphenols which possess the activity for enhancing the lysosomal degradation in J774.1, a murine macrophage-like cell line. Screening test utilizing DQ-BSA digestion identified isorhamnetin (3'-O-methylquercetin) as an active compound. Interestingly, structural comparison to inactive flavonols revealed that the chemical structure of the B-ring moiety in isorhamnetin is the primary determinant of its lysosome-enhancing activity. Unexpectedly isorhamnetin failed to inhibit mTORC1-TFEB signaling, a master regulator of lysosomal biogenesis and function. Our data suggested that the other molecular mechanism might be critical for the regulation of lysosomes in macrophages.Abbreviations: ANOVA: analysis of variance; ApoE: apolipoprotein E; ATP6V0D2: ATPase H+ transporting V0 subunit d2; BAF: bafilomycin A1; BODIPY: boron dipyrromethene; BSA: bovine serum albumin; CTSD: cathepsin D; CTSF: cathepsin F; DMEM: Dulbecco's modified eagle medium; DMSO: dimethyl sulfoxide; EGCG: epigallocatechin-3-gallate; FBS: fetal bovine serum; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HPLC: high-performance liquid chromatography; LAMP1: lysosomal-associated membrane protein 1; LAMP2A: lysosomal-associated membrane protein 2A; LC-MS/MS: liquid chromatography tandem mass spectrometry; MITF: microphthalmia-associated transcription factor; MRM: multiple reaction monitoring; mTORC1: mechanistic target of rapamycin complex 1; PBS: phosphate-buffered saline; PPARγ: peroxisome proliferator-activated receptor γ; RT-qPCR: reverse transcription quantitative polymerase chain reaction; SDS: sodium dodecyl sulfate; SNARE: soluble N-ethylmaleimide-sensitive-factor attachment protein receptor; TBS: Tris-buffered saline; TFA: trifluoroacetic acid; TFE3: transcription factor binding to IGHM enhancer 3; TFEB: transcriptional factor EB; TFEC: transcription factor EC; V-ATPase: vacuolar-type proton ATPase.
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Affiliation(s)
- Maiko Sakai
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kohta Ohnishi
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Masashi Masuda
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Hirokazu Ohminami
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Hisami Yamanaka-Okumura
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Taichi Hara
- Laboratory of Food and Life Science, Faculty of Human Sciences, Waseda University, Saitama, Japan
| | - Yutaka Taketani
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
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Tan KT, Ang STJ, Tsai SY. Sarcopenia: Tilting the Balance of Protein Homeostasis. Proteomics 2019; 20:e1800411. [PMID: 31722440 DOI: 10.1002/pmic.201800411] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 11/04/2019] [Indexed: 12/14/2022]
Abstract
Sarcopenia, defined as age-associated decline of muscle mass and function, is a risk factor for mortality and disability, and comorbid with several chronic diseases such as type II diabetes and cardiovascular diseases. Clinical trials showed that nutritional supplements had positive effects on muscle mass, but not on muscle function and strength, demonstrating our limited understanding of the molecular events involved in the ageing muscle. Protein homeostasis, the equilibrium between protein synthesis and degradation, is proposed as the major mechanism underlying the development of sarcopenia. As the key central regulator of protein homeostasis, the mammalian target of rapamycin (mTOR) is proposed to be essential for muscle hypertrophy. Paradoxically, sustained activation of mTOR complex 1 (mTORC1) is associated with a loss of sensitivity to extracellular signaling in the elderly. It is not understood why sustained mTORC1 activity, which should induce muscle hypertrophy, instead results in muscle atrophy. Here, recent findings on the implications of disrupting protein homeostasis on muscle physiology and sarcopenia development in the context of mTOR/protein kinase B (AKT) signaling are reviewed. Understanding the role of these molecular mechanisms during the ageing process will contribute towards the development of targeted therapies that will improve protein metabolism and reduce sarcopenia.
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Affiliation(s)
- Kuan Ting Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Seok-Ting Jamie Ang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
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Robert G, Jacquel A, Auberger P. Chaperone-Mediated Autophagy and Its Emerging Role in Hematological Malignancies. Cells 2019; 8:cells8101260. [PMID: 31623164 PMCID: PMC6830112 DOI: 10.3390/cells8101260] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/04/2019] [Accepted: 10/11/2019] [Indexed: 12/19/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) ensures the selective degradation of cellular proteins endowed with a KFERQ-like motif by lysosomes. It is estimated that 30% of all cellular proteins can be directed to the lysosome for CMA degradation, but only a few substrates have been formally identified so far. Mechanistically, the KFERQ-like motifs present in substrate proteins are recognized by the molecular chaperone Hsc70c (Heat shock cognate 71 kDa protein cytosolic), also known as HSPA8, and directed to LAMP2A, which acts as the CMA receptor at the lysosomal surface. Following linearization, the protein substrate is next transported to the lumen of the lysosomes, where it is degraded by resident proteases, mainly cathepsins and eventually recycled to sustain cellular homeostasis. CMA is induced by different stress conditions, including energy deprivation that also activates macro-autophagy (MA), that may make it difficult to decipher the relative impact of both pathways on cellular homeostasis. Besides common inducing triggers, CMA and MA might be induced as compensatory mechanisms when either mechanism is altered, as it is the often the case in different pathological settings. Therefore, CMA activation can compensate for alterations of MA and vice versa. In this context, these compensatory mechanisms, when occurring, may be targeted for therapeutic purposes. Both processes have received particular attention from scientists and clinicians, since modulation of MA and CMA may have a profound impact on cellular proteostasis, metabolism, death, differentiation, and survival and, as such, could be targeted for therapeutic intervention in degenerative and immune diseases, as well as in cancer, including hematopoietic malignancies. The role of MA in cancer initiation and progression is now well established, but whether and how CMA is involved in tumorigenesis has been only sparsely explored. In the present review, we encompass the description of the mechanisms involved in CMA, its function in the physiology and pathogenesis of hematopoietic cells, its emerging role in cancer initiation and development, and, finally, the potential therapeutic opportunity to target CMA or CMA-mediated compensatory mechanisms in hematological malignancies.
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Affiliation(s)
- Guillaume Robert
- Mediterranean Center for Molecular Medicine ,Université Nice Côte d'Azur, C3M/Inserm1065, 06100 Nice, France.
| | - Arnaud Jacquel
- Mediterranean Center for Molecular Medicine ,Université Nice Côte d'Azur, C3M/Inserm1065, 06100 Nice, France
| | - Patrick Auberger
- Mediterranean Center for Molecular Medicine ,Université Nice Côte d'Azur, C3M/Inserm1065, 06100 Nice, France.
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Loeffler DA. Influence of Normal Aging on Brain Autophagy: A Complex Scenario. Front Aging Neurosci 2019; 11:49. [PMID: 30914945 PMCID: PMC6421305 DOI: 10.3389/fnagi.2019.00049] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/19/2019] [Indexed: 12/12/2022] Open
Abstract
Misfolded proteins are pathological findings in some chronic neurodegenerative disorders including Alzheimer's, Parkinson's, and Huntington's diseases. Aging is a major risk factor for these disorders, suggesting that the mechanisms responsible for clearing misfolded proteins from the brain, the ubiquitin-proteasome system and the autophagy-lysosomal pathway, may decline with age. Although autophagic mechanisms have been found to decrease with age in many experimental models, whether they do so in the brain is unclear. This review examines the literature with regard to age-associated changes in macroautophagy and chaperone-mediated autophagy (CMA) in the central nervous system (CNS). Beclin 1, LC3-II, and the LC3-II/LC3-I ratio have frequently been used to examine changes in macroautophagic activity, while lamp2a and HSPA8 (also known as hsc70) have been used to measure CMA activity. Three gene expression analyses found evidence for an age-related downregulation of macroautophagy in human brain, but no published studies were found of age-related changes in CMA in human brain, although cerebrospinal fluid concentrations of HSPA8 were reported to decrease with age. Most studies of age-related changes in brain autophagy in experimental animals have found age-related declines in macroautophagy, and macroautophagy is necessary for normal lifespan in Caenorhabditis elegans, Drosophila, and mice. However, the few studies of age-related changes in brain CMA in experimental animals have produced conflicting results. Investigations of the influence of aging on macroautophagy in experimental animals in systems other than the CNS have generally found an age-related decrease in Beclin 1, but conflicting results for LC3-II and the LC3-II/LC3-I ratio, while CMA decreases with age in most models. CONCLUSION: while indirect evidence suggests that brain autophagy may decrease with normal aging, this issue has not been investigated sufficiently, particularly in human brain. Measuring autophagic activity in the brain can be challenging because of differences in basal autophagic activity between experimental models, and the inability to include lysosomal inhibitors when measuring the LC3-II/LC3-I ratio in postmortem specimens. If autophagy does decrease in the brain with aging, then pharmacological interventions and/or lifestyle alterations to slow this decline could reduce the risk of developing age-related neurodegenerative disorders.
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Affiliation(s)
- David A Loeffler
- Beaumont Research Institute, Department of Neurology, Beaumont Health, Royal Oak, MI, United States
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Ni J, Wu Z, Stoka V, Meng J, Hayashi Y, Peters C, Qing H, Turk V, Nakanishi H. Increased expression and altered subcellular distribution of cathepsin B in microglia induce cognitive impairment through oxidative stress and inflammatory response in mice. Aging Cell 2019; 18:e12856. [PMID: 30575263 PMCID: PMC6351837 DOI: 10.1111/acel.12856] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 07/02/2018] [Accepted: 09/02/2018] [Indexed: 11/30/2022] Open
Abstract
During normal aging, innate immunity progresses to a chronic state. However, how oxidative stress and chronic neuroinflammation arise during aging remains unclear. In this study, we found that genetic ablation of cathepsin B (CatB) in mice significantly reduced the generation of reactive oxygen species (ROS) and neuroinflammation and improved cognitive impairment during aging. In cultured microglia, pharmacological inhibition of CatB significantly reduced the generation of mitochondria‐derived ROS and proinflammatory mediators induced by L‐leucyl‐L‐leucine methyl ester (LLOMe), a lysosome‐destabilizing agent. In the CatB‐overexpressing microglia after treatment with LLOMe, which mimicked the aged microglia, CatB leaked in the cytosol is responsible for the degradation of the mitochondrial transcription factor A (TFAM), resulting in the increased generation of mitochondria‐derived ROS and proinflammatory mediators through impaired mtDNA biosynthesis. Furthermore, intralateral ventricle injection of LLOMe‐treated CatB‐overexpressing microglia induced cognitive impairment in middle‐aged mice. These results suggest that the increase and leakage of CatB in microglia during aging are responsible for the increased generation of mitochondria‐derived ROS and proinflammatory mediators, culminating in memory impairment.
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Affiliation(s)
- Junjun Ni
- Department of Aging Science and Pharmacology, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Zhou Wu
- Department of Aging Science and Pharmacology, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Veronika Stoka
- Department of Biochemistry and Molecular and Structural Biology; J. Stefan Institute; Ljubljana Slovenia
| | - Jie Meng
- Department of Aging Science and Pharmacology, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Yoshinori Hayashi
- Department of Aging Science and Pharmacology, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Christoph Peters
- Institute für Molekulare Medizin und Zellforshung; Albert-Ludwigs-Universität Freiburg; Freiburg Germany
| | - Hong Qing
- Beijing Key Laboratory of Separation and Analysis in Biomedical and Pharmaceuticals, Department of Biomedical Engineering, School of Life Science; Beijing Institute of Technology; Beijing China
| | - Vito Turk
- Department of Biochemistry and Molecular and Structural Biology; J. Stefan Institute; Ljubljana Slovenia
| | - Hiroshi Nakanishi
- Department of Aging Science and Pharmacology, Faculty of Dental Science; Kyushu University; Fukuoka Japan
- Department of Pharmacology, Faculty of Pharmacy; Yasuda Women’s University; Hiroshima Japan
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LAMP2 expression dictates azacytidine response and prognosis in MDS/AML. Leukemia 2019; 33:1501-1513. [PMID: 30607021 DOI: 10.1038/s41375-018-0336-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 11/21/2018] [Accepted: 11/28/2018] [Indexed: 12/31/2022]
Abstract
Chaperone-mediated autophagy (CMA) is a highly selective form of autophagy. During CMA, the HSC70 chaperone carries target proteins endowed with a KFERQ-like motif to the lysosomal receptor LAMP2A, which then translocate them into lysosomes for degradation. In the present study, we scrutinized the mechanisms underlying the response and resistance to Azacytidine (Aza) in MDS/AML cell lines and bone marrow CD34+ blasts from MDS/AML patients. In engineered Aza-resistant MDS cell lines and some AML cell lines, we identified a profound defect in CMA linked to the absence of LAMP2A. LAMP2 deficiency was responsible for Aza resistance and hypersensitivity to lysosome and autophagy inhibitors. Accordingly, gain of function of LAMP2 in deficient cells or loss of function in LAMP2-expressing cells rendered them sensitive or resistant to Aza, respectively. A strict correlation was observed between the absence of LAMP2, resistance to Aza and sensitivity to lysosome inhibitors. Low levels of LAMP2 expression in CD34+ blasts from MDS/AML patients correlated with lack of sensitivity to Aza and were predictive of poor overall survival. We propose that CD34+/LAMP2Low patients at diagnosis or who become CD34+/LAMP2Low during the course of treatment with Aza might benefit from a lysosome inhibitor already used in the clinic.
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Loeffler DA, Klaver AC, Coffey MP, Aasly JO. Cerebrospinal Fluid Concentration of Key Autophagy Protein Lamp2 Changes Little During Normal Aging. Front Aging Neurosci 2018; 10:130. [PMID: 29867441 PMCID: PMC5952035 DOI: 10.3389/fnagi.2018.00130] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/17/2018] [Indexed: 12/27/2022] Open
Abstract
Autophagy removes both functional and damaged intracellular macromolecules from cells via lysosomal degradation. Three autophagic mechanisms, namely macroautophagy, chaperone-mediated autophagy (CMA), and microautophagy, have been described in mammals. Studies in experimental systems have found macroautophagy and CMA to decrease with normal aging, despite the fact that oxidative stress, which can activate both processes, increases with normal aging. Whether autophagic mechanisms decrease in the human brain during normal aging is unclear. The primary objective of this study was to examine the association of a major autophagy protein, lysosome-associated membrane glycoprotein (lamp2), with age in cerebrospinal fluid (CSF) samples from healthy subjects. Lamp2 consists of three isoforms, lamp2a, 2b and 2c, all of which participate in autophagy. Lamp2's CSF concentration decreases in Parkinson's disease (PD) and increases in Alzheimer's disease (AD), but whether its CSF concentration changes during normal aging has not been investigated. Our secondary objectives were to examine the associations of lamp2's CSF concentration with CSF levels of the molecular chaperone heat shock 70-kDa protein (HSPA8), which interacts with lamp2a in CMA, and oxidative stress markers 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-isoprostane (8-ISO) and Total Antioxidant Capacity (TAC) in healthy subjects. We found lamp2's observed associations with these variables to be weak, with all Kendall's tau-b absolute values ≤0.20. These results suggest that CSF lamp2 concentration changes little during normal aging and does not appear to be associated with HSPA8 or oxidative stress. Further studies are indicated to determine the relationship between CSF lamp2 concentration and brain autophagic processes.
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Affiliation(s)
- David A Loeffler
- Department of Neurology, Beaumont Hospital-Royal Oak, Beaumont Health, Royal Oak, MI, United States
| | - Andrea C Klaver
- Department of Neurology, Beaumont Hospital-Royal Oak, Beaumont Health, Royal Oak, MI, United States
| | - Mary P Coffey
- Department of Biostatistics, Beaumont Hospital-Royal Oak, Beaumont Health, Royal Oak, MI, United States
| | - Jan O Aasly
- Department of Neurology, St. Olav's Hospital, Trondheim, Norway
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Li L, Wang W, Zhang R, Liu J, Yu J, Wu X, Xu Y, Ma M, Huang J. High expression of LAMP2 predicts poor prognosis in patients with esophageal squamous cell carcinoma. Cancer Biomark 2018; 19:305-311. [PMID: 28453465 DOI: 10.3233/cbm-160469] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND LAMP2 is one of the major protein components of lysosome. In addition to the expression on the lysosomal membrane, LAMP2 has also been found relocalizing to the cell surface of some highly metastatic tumor cells. OBJECTIVE The aim of this study was to detect the expression levels of LAMP2 and discuss its roles in esophageal squamous cell carcinoma (ESCC). METHODS Six hundred and ten tissue samples of ESCC were collected to construct tissue microarrays, which were stained by immunohistochemistry. RESULTS After immunohistochemical staining, 596 patients including 460 men and 136 women were analyzed. The LAMP2 expression levels were significantly different based on degrees of histological differentiation (χ2= 108.906, P< 0.001). The similar results were also observed in TNM stages (χ2= 23.835, P< 0.01). LAMP2 expression levels negatively correlated with degrees of histological differentiation (P< 0.01). Logistic regression analysis showed that the LAMP2 expression levels were correlated with the degrees of histological differentiation (OR=𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑡𝑖𝑎𝑡𝑖𝑜𝑛 0.452, P< 0.001) and TNM stages (OR=𝑇𝑁𝑀 1.482, P= 0.42). Besides, Kaplan-Meier survival curves indicated that patients with higher expression of LAMP2 exhibited poor prognosis (P< 0.05). CONCLUSIONS Our results demonstrated that LAMP2 expression levels correlated with tumor histological differentiation and TNM stages. High expression of LAMP2 predicts poor prognosis in patients with ESCC.
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Affiliation(s)
- Lei Li
- Department of Pathology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Wei Wang
- Department of Pathology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Renya Zhang
- Department of Pathology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Jianli Liu
- Department of Pathology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Juan Yu
- Department of Pathology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Xiaoxiao Wu
- Department of Pathology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Ying Xu
- Department of Pathology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Ming Ma
- Thoracic Surgery, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Jian Huang
- Central Laboratory, Affiliated Hospital of Jining Medical University, Jining, Shandong, China
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12
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Zhang Y, Huang J, Yang X, Sun X, Xu Q, Wang B, Zhong P, Wei Z. Altered Expression of TXNIP in the peripheral leukocytes of patients with coronary atherosclerotic heart disease. Medicine (Baltimore) 2017; 96:e9108. [PMID: 29245343 PMCID: PMC5728958 DOI: 10.1097/md.0000000000009108] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Coronary atherosclerotic heart disease (CAD) is mainly caused by atherosclerosis, an inflammatory disease characterized by plaque formation in arteries. Reactive oxygen species caused structural damage and dysfunction of arterial endothelial cells. Thioredoxin-interacting protein (TXNIP) is the endogenous inhibitor and regulator of thioredoxin, a major cellular antioxidant and antiapoptotic system. In order to explore the role of TXNIP in the occurrence and development of CAD, we detected the TXNIP expression and discussed its molecular mechanisms in CAD. METHODS The mRNA levels of TXNIP gene in peripheral leucocytes were detected in CAD and healthy controls (CTR) by quantitative real-time polymerase chain reaction. And TXNIP proteins were detected by western blotting. RESULTS TXNIP gene expression levels in patients with unstable angina pectoris (UAP, n = 96) were significantly increased compared with those of CTR (n = 192, P < .05). However, the situation is different in acute myocardial infarction (n = 96, P > .05). Logistic regression analysis showed that TXNIP levels were significantly positive correlated with UAP (OR = 1.728, P < .05). CONCLUSIONS TXNIP gene expression in the peripheral leucocytes was increased in patients with UAP, indicating that TXNIP in circulating leucocytes may be involved in the pathogenesis of UAP.
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Affiliation(s)
- Yujing Zhang
- Department of Cardiology, Jining No. 1 People's Hospital
| | - Jian Huang
- Central Laboratory, Affiliated Hospital of Jining Medical University
| | - Xinglin Yang
- Department of Traditional Chinese Medicine, Jining No. 1 People's Hospital, Shandong, China
| | - Xiaofei Sun
- Department of Cardiology, Jining No. 1 People's Hospital
| | - Qincheng Xu
- Department of Cardiology, Jining No. 1 People's Hospital
| | - Baokui Wang
- Department of Cardiology, Jining No. 1 People's Hospital
| | - Peng Zhong
- Department of Cardiology, Jining No. 1 People's Hospital
| | - Zixiu Wei
- Department of Cardiology, Jining No. 1 People's Hospital
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Mejías-Peña Y, Estébanez B, Rodriguez-Miguelez P, Fernandez-Gonzalo R, Almar M, de Paz JA, González-Gallego J, Cuevas MJ. Impact of resistance training on the autophagy-inflammation-apoptosis crosstalk in elderly subjects. Aging (Albany NY) 2017; 9:408-418. [PMID: 28160545 PMCID: PMC5361672 DOI: 10.18632/aging.101167] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/25/2017] [Indexed: 12/13/2022]
Abstract
Aging is associated with a decline in autophagy and a state of low-grade inflammation which further affects apoptosis and autophagy. Importantly, these alterations could reverse with regular physical activity. This study assessed the effects of a resistance exercise training program on autophagy, NLRP3 inflammasome, and apoptosis in peripheral blood mononuclear cells (PBMCs) from old subjects. Twenty-six healthy women and men (age, 69.6±1.5 yr) were randomized to a training (TG) or a control (CG) group. TG performed an 8-week resistance training program, while CG followed their daily routines. Protein expression of beclin-1, Atg12, Atg16 and LAMP-2 increased following the training program, while expression of p62/SQSTM1 and phosphorylation of ULK-1 at Ser757 were significantly lower. Resistance exercise also induced a decrease in NLRP3 expression and in the caspase-1/procaspase-1 ratio. Expression of Bcl-2 and Bcl-xL, as well as the Bad/BcL-2 ratio were reduced, and there was a significant decrease in the protein content of caspase-3. The results obtained seem to indicate that 8-week resistance training stimulates autophagy, prevents NLRP3 inflammasome activation, and reduces apoptosis in PBMCs from elderly subjects. These data could have a significant impact in prevention and rehabilitation programs currently employed in elderly population.
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Affiliation(s)
| | | | - Paula Rodriguez-Miguelez
- Division of Clinical Translational Science, Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, GA, USA
| | - Rodrigo Fernandez-Gonzalo
- Radiobiology Unit, Laboratory of Molecular and Cellular Biology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
| | - Mar Almar
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
| | - José A de Paz
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
| | | | - María J Cuevas
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
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Miller JW, Bagheri S, Vavvas DG. Advances in Age-related Macular Degeneration Understanding and Therapy. ACTA ACUST UNITED AC 2017; 10:119-130. [PMID: 29142592 PMCID: PMC5683729 DOI: 10.17925/usor.2017.10.02.119] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
While the development of anti-vascular endothelial growth factor (anti-VEGF) as a therapy for neovascular age-related macular degeneration (AMD) was a great success, the pathologic processes underlying dry AMD that eventually leads to photoreceptor dysfunction, death, and vision loss remain elusive to date, with a lack of effective therapies and increasing prevalence of the disease. There is an overwhelming need to improve the classification system of AMD, to increase our understanding of cell death mechanisms involved in both neovascular and non-neovascular AMD, and to develop better biomarkers and clinical endpoints to eventually be able to identify better therapeutic targets—especially early in the disease process. There is no doubt that it is a matter of time before progress will be made and better therapies will be developed for non-neovascular AMD.
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Affiliation(s)
- Joan W Miller
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, US
| | - Saghar Bagheri
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, US
| | - Demetrios G Vavvas
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, US
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15
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Mejías-Peña Y, Rodriguez-Miguelez P, Fernandez-Gonzalo R, Martínez-Flórez S, Almar M, de Paz JA, Cuevas MJ, González-Gallego J. Effects of aerobic training on markers of autophagy in the elderly. AGE (DORDRECHT, NETHERLANDS) 2016; 38:33. [PMID: 26940016 PMCID: PMC5005904 DOI: 10.1007/s11357-016-9897-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 02/23/2016] [Indexed: 05/16/2023]
Abstract
Autophagy is a molecular process essential for the maintenance of cellular homeostasis, which appears to (i) decline with age and (ii) respond to physical exercise. In addition, recent evidence suggests a crosstalk between autophagy and toll-like receptor (TLR)-associated inflammatory responses. This study assessed the effects of aerobic exercise training on autophagy and TLR signaling in older subjects. Twenty-nine healthy women and men (age, 69.7 ± 1.0 year) were randomized to a training (TG) or a control (CG) group. TG performed an 8-week aerobic training program, while CG followed their daily routines. Peripheral blood mononuclear cells were isolated from blood samples obtained before and after the intervention, and protein levels of protein 1 light chain 3 (LC3), sequestosome 1 (p62/SQSTM1), beclin-1, phosphorylated unc-51-like kinase (ULK-1), ubiquitin-like autophagy-related (Atg)12, Atg16, and lysosome-associated membrane protein (LAMP)-2 were measured. TLR2 and TLR4 signaling pathways were also analyzed. Peak oxygen uptake increased in TG after the intervention. Protein expression of beclin-1, Atg12, Atg16, and the LC3II/I ratio increased following the training program (p < 0.05), while expression of p62/SQSTM1 and phosphorylation of ULK-1 at Ser(757) were lower (p < 0.05). Protein content of TLR2, TLR4, myeloid differentiation primary response gen 88 (MyD88), and TIR domain-containing adaptor-inducing interferon (TRIF) were not significantly modified by exercise. The current data indicate that aerobic exercise training induces alterations in multiple markers of autophagy, which seem to be unrelated to changes in TLR2 and TLR4 signaling pathways. These results expand knowledge on exercise-induced autophagy adaptations in humans and suggest that the exercise type employed may be a key factor explaining the potential relationship between autophagy and TLR pathways.
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Affiliation(s)
- Yubisay Mejías-Peña
- Institute of Biomedicine (IBIOMED), University of León, Campus Vegazana s/n, 24071, León, Spain
| | - Paula Rodriguez-Miguelez
- Divisions of Clinical and Translational Sciences, Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, USA
| | | | - Susana Martínez-Flórez
- Institute of Biomedicine (IBIOMED), University of León, Campus Vegazana s/n, 24071, León, Spain
| | - Mar Almar
- Institute of Biomedicine (IBIOMED), University of León, Campus Vegazana s/n, 24071, León, Spain
| | - José A de Paz
- Institute of Biomedicine (IBIOMED), University of León, Campus Vegazana s/n, 24071, León, Spain
| | - María J Cuevas
- Institute of Biomedicine (IBIOMED), University of León, Campus Vegazana s/n, 24071, León, Spain
| | - Javier González-Gallego
- Institute of Biomedicine (IBIOMED), University of León, Campus Vegazana s/n, 24071, León, Spain.
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Murphy KE, Gysbers AM, Abbott SK, Spiro AS, Furuta A, Cooper A, Garner B, Kabuta T, Halliday GM. Lysosomal-associated membrane protein 2 isoforms are differentially affected in early Parkinson's disease. Mov Disord 2015; 30:1639-47. [DOI: 10.1002/mds.26141] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 01/09/2023] Open
Affiliation(s)
- Karen E. Murphy
- Neuroscience Research Australia; Sydney Australia
- School of Medical Sciences, Faculty of Medicine, The University of New South Wales; Sydney Australia
| | | | - Sarah K. Abbott
- Illawarra Health and Medical Research Institute; Wollongong Australia
- School of Biological Sciences, Faculty of Science, Medicine and Health, University of Wollongong; Wollongong Australia
| | - Adena S. Spiro
- Illawarra Health and Medical Research Institute; Wollongong Australia
- School of Biological Sciences, Faculty of Science, Medicine and Health, University of Wollongong; Wollongong Australia
| | - Akiko Furuta
- Department of Degenerative Neurological Diseases; National Institute of Neuroscience, National Center of Neurology and Psychiatry; Kodaira Tokyo Japan
| | - Antony Cooper
- The Garvan Institute of Medical Research; Sydney Australia
- St Vincent's Clinical School, Faculty of Medicine, and School of Biotechnology and Biomolecular Sciences, Faculty of Science, The University of New South Wales; Sydney Australia
| | - Brett Garner
- Illawarra Health and Medical Research Institute; Wollongong Australia
- School of Biological Sciences, Faculty of Science, Medicine and Health, University of Wollongong; Wollongong Australia
| | - Tomohiro Kabuta
- Department of Degenerative Neurological Diseases; National Institute of Neuroscience, National Center of Neurology and Psychiatry; Kodaira Tokyo Japan
| | - Glenda M. Halliday
- Neuroscience Research Australia; Sydney Australia
- School of Medical Sciences, Faculty of Medicine, The University of New South Wales; Sydney Australia
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Chaperone-mediated autophagy: dedicated saviour and unfortunate victim in the neurodegeneration arena. Biochem Soc Trans 2014; 41:1483-8. [PMID: 24256241 DOI: 10.1042/bst20130126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The importance of cellular quality-control systems in the maintenance of neuronal homoeostasis and in the defence against neurodegeneration is well recognized. Chaperones and proteolytic systems, the main components of these cellular surveillance mechanisms, are key in the fight against the proteotoxicity that is often associated with severe neurodegenerative diseases. However, in recent years, a new theme has emerged which suggests that components of protein quality-control pathways are often targets of the toxic effects of pathogenic proteins and that their failure to function properly contributes to pathogenesis and disease progression. In the present mini-review, we describe this dual role as 'saviour' and 'victim' in the context of neurodegeneration for chaperone-mediated autophagy, a cellular pathway involved in the selective degradation of cytosolic proteins in lysosomes.
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Kan L, Mutso AA, McGuire TL, Apkarian AV, Kessler JA. Opioid signaling in mast cells regulates injury responses associated with heterotopic ossification. Inflamm Res 2013; 63:207-15. [PMID: 24327087 DOI: 10.1007/s00011-013-0690-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/18/2013] [Accepted: 11/20/2013] [Indexed: 10/25/2022] Open
Abstract
INTRODUCTION Previous studies found that neuron specific enolase promoter (Nse-BMP4) transgenic mice have increased expression of the nociceptive mediator, substance P and exaggerated local injury responses associated with heterotopic ossification (HO). It is of interest great to know the pain responses in these mice and how the opioid signaling is involved in the downstream events such as mast cell (MC) activation. MATERIALS AND METHODS This study utilized a transgenic mouse model of HO in which BMP4 is expressed under the control of the Nse-BMP4. The tactile sensitivity and the cold sensitivity of the mice were measured in a classic inflammatory pain model (carrageenan solution injected into the plantar surface of the left hind paw). The MC activation and the expression profiles of different components in the opioid signaling were demonstrated through routine histology and immunohistochemistry and Western blotting, in the superficial and deep muscle injury models. RESULTS We found that the pain responses in these mice were paradoxically attenuated or unchanged, and we also found increased expression of both Methionine Enkephalin (Met-Enk), and the μ-opioid receptor (MOR). Met-Enk and MOR both co-localized within activated MCs in limb tissues. Further, Nse-BMP4;MOR(-/-) double mutant mice showed attenuated MC activation and had a significant reduction in HO formation in response to injuries. CONCLUSIONS These observations suggest that opioid signaling may play a key role in MC activation and the downstream inflammatory responses associated with HO. In addition to providing insight into the role of MC activation and associated injury responses in HO, these findings suggest opioid signaling as a potential therapeutic target in HO and possibly others disorders involving MC activation.
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Affiliation(s)
- Lixin Kan
- Department of Neurology, Northwestern University, Ward Building 10-233, 303 East Chicago Avenue, Chicago, IL, 60611-3008, USA,
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What is the evidence for antibodies to LAMP-2 in the pathogenesis of ANCA associated small vessel vasculitis? Curr Opin Rheumatol 2013; 25:26-34. [PMID: 23169102 DOI: 10.1097/bor.0b013e32835b4f8f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE OF REVIEW This review critically analyses the data implicating antibodies to lysosome associated membrane protein-2 (hLAMP-2) in ANCA-associated vasculitis (AAV). It addresses recent controversies over prevalence of anti-hLAMP-2 antibodies as well as their potential for diagnosis and monitoring disease activity. RECENT FINDINGS Anti-hLAMP-2 antibodies were first described in the 1990s and have become the focus of intense clinical interest in the past 4 years. This followed the demonstration of their very high prevalence in untreated patients presenting with AAV but absence when patients were in remission. The data also demonstrated molecular mimicry between hLAMP-2 and the bacterial protein FimH. The same group later confirmed the original findings and showed the anti-hLAMP-2 autoantibodies have different kinetics to those recognising myeloperoxidase and proteinase-3 and are less likely to be detectable when the disease is in remission. By contrast, a different group reported a lower prevalence of anti-hLAMP-2 antibodies in AAV and questioned their relevance to pathogenesis. Critical analysis of these studies suggests that the differences are largely attributable to selection criteria of the AAV patients studied and the assays used. SUMMARY Anti-hLAMP-2 antibodies are frequently found in AAV but attempts to define their consequences have been frustrated by lack of generally available assays for them.
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