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Wu N, Zheng W, Zhou Y, Tian Y, Tang M, Feng X, Ashrafizadeh M, Wang Y, Niu X, Tambuwala M, Wang L, Tergaonkar V, Sethi G, Klionsky D, Huang L, Gu M. Autophagy in aging-related diseases and cancer: Principles, regulatory mechanisms and therapeutic potential. Ageing Res Rev 2024; 100:102428. [PMID: 39038742 DOI: 10.1016/j.arr.2024.102428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/05/2024] [Accepted: 07/15/2024] [Indexed: 07/24/2024]
Abstract
Macroautophagy/autophagy is primarily accountable for the degradation of damaged organelles and toxic macromolecules in the cells. Regarding the essential function of autophagy for preserving cellular homeostasis, changes in, or dysfunction of, autophagy flux can lead to disease development. In the current paper, the complicated function of autophagy in aging-associated pathologies and cancer is evaluated, highlighting the underlying molecular mechanisms that can affect longevity and disease pathogenesis. As a natural biological process, a reduction in autophagy is observed with aging, resulting in an accumulation of cell damage and the development of different diseases, including neurological disorders, cardiovascular diseases, and cancer. The MTOR, AMPK, and ATG proteins demonstrate changes during aging, and they are promising therapeutic targets. Insulin/IGF1, TOR, PKA, AKT/PKB, caloric restriction and mitochondrial respiration are vital for lifespan regulation and can modulate or have an interaction with autophagy. The specific types of autophagy, such as mitophagy that degrades mitochondria, can regulate aging by affecting these organelles and eliminating those mitochondria with genomic mutations. Autophagy and its specific types contribute to the regulation of carcinogenesis and they are able to dually enhance or decrease cancer progression. Cancer hallmarks, including proliferation, metastasis, therapy resistance and immune reactions, are tightly regulated by autophagy, supporting the conclusion that autophagy is a promising target in cancer therapy.
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Affiliation(s)
- Na Wu
- Department of Infectious Diseases, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Wenhui Zheng
- Department of Anesthesiology, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Yundong Zhou
- Department of Thoracic Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo University, Ningbo, Zhejiang 315040, China
| | - Yu Tian
- School of Public Health, Benedictine University, No.5700 College Road, Lisle, IL 60532, USA; Research Center, the Huizhou Central People's Hospital, Guangdong Medical University, Huizhou, Guangdong, China
| | - Min Tang
- Department of Oncology, Chongqing General Hospital, Chongqing University, Chongqing 401120, China
| | - Xiaoqiang Feng
- Center of Stem Cell and Regenerative Medicine, Gaozhou People's Hospital, Gaozhou, Guangdong 525200, China
| | - Milad Ashrafizadeh
- Department of Radiation Oncology, Shandong Provincial Key Laboratory of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, Shandong 250000, China; Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Yuzhuo Wang
- Department of Urologic Sciences and Vancouver Prostate Centre, University of British Columbia, Vancouver, BC V6H3Z6, Canada
| | - Xiaojia Niu
- Department of Urologic Sciences and Vancouver Prostate Centre, University of British Columbia, Vancouver, BC V6H3Z6, Canada
| | - Murtaza Tambuwala
- Lincoln Medical School, University of Lincoln, Brayford Pool Campus, Lincoln LN6 7TS, UK
| | - Lingzhi Wang
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive, Singapore 117600, Singapore
| | - Vinay Tergaonkar
- Laboratory of NF-κB Signalling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A⁎STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive, Singapore 117600, Singapore; NUS Centre for Cancer Research (N2CR), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore.
| | - Daniel Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
| | - Li Huang
- Center of Stem Cell and Regenerative Medicine, Gaozhou People's Hospital, Gaozhou, Guangdong 525200, China.
| | - Ming Gu
- Department of Breast Surgery, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China.
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2
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Bensalem J, Teong XT, Hattersley KJ, Hein LK, Fourrier C, Liu K, Hutchison AT, Heilbronn LK, Sargeant TJ. Basal autophagic flux measured in blood correlates positively with age in adults at increased risk of type 2 diabetes. GeroScience 2023; 45:3549-3560. [PMID: 37498479 PMCID: PMC10643809 DOI: 10.1007/s11357-023-00884-5] [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: 05/24/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023] Open
Abstract
Preclinical data show that autophagy delays age-related disease. It has been postulated that age-related disease is-at least in part-caused by an age-related decline in autophagy. However, autophagic flux has never been measured in humans across a spectrum of aging in a physiologically relevant context. To address this critical gap in knowledge, the objective of this cross-sectional observational study was to measure basal autophagic flux in whole blood taken from people at elevated risk of developing type 2 diabetes and correlate it with chronological age. During this study, 119 people were recruited and five people were excluded during sample analysis such that 114 people were included in the final analysis. Basal autophagic flux measured in blood and correlations with parameters such as age, body weight, fat mass, AUSDRISK score, blood pressure, glycated hemoglobin HbA1c, blood glucose and insulin, blood lipids, high-sensitivity C-reactive protein, plasma protein carbonylation, and plasma β-hexosaminidase activity were analysed. Despite general consensus in the literature that autophagy decreases with age, we found that basal autophagic flux increased with age in this human cohort. This is the first study to report measurement of basal autophagic flux in a human cohort and its correlation with age. This increase in basal autophagy could represent a stress response to age-related damage. These data are significant not only for their novelty but also because they will inform future clinical studies and show that measurement of basal autophagic flux in a human cohort is feasible.
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Affiliation(s)
- Julien Bensalem
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Xiao Tong Teong
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Kathryn J Hattersley
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Leanne K Hein
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Célia Fourrier
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Kai Liu
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Amy T Hutchison
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Leonie K Heilbronn
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Timothy J Sargeant
- Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
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3
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Sebti S, Zou Z, Shiloh MU. BECN1 F121A mutation increases autophagic flux in aged mice and improves aging phenotypes in an organ-dependent manner. Autophagy 2023; 19:957-965. [PMID: 35993269 PMCID: PMC9980460 DOI: 10.1080/15548627.2022.2111852] [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: 02/03/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 01/18/2023] Open
Abstract
Macroautophagy/autophagy is necessary for lifespan extension in multiple model organisms and autophagy dysfunction impacts age-related phenotypes and diseases. Introduction of an F121A mutation into the essential autophagy protein BECN1 constitutively increases basal autophagy in young mice and reduces cardiac and renal age-related changes in longer lived Becn1F121A mutant mice. However, both autophagic and lysosomal activities decline with age. Thus, whether autophagic flux is maintained during aging and whether it is enhanced in Becn1F121A mice is unknown. Here, we demonstrate that old wild-type mice maintained functional autophagic flux in heart, kidney and skeletal muscle but not liver, and old Becn1F121A mice had increased autophagic flux in those same organs compared to wild type. In parallel, Becn1F121A mice were not protected against age-associated hepatic phenotypes but demonstrated reduced skeletal muscle fiber atrophy. These findings identify an organ-specific role for the ability of autophagy to impact organ aging phenotypes.
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Affiliation(s)
- Salwa Sebti
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zhongju Zou
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Michael U. Shiloh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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4
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Transcriptional regulation of autophagy in aging. CURRENT OPINION IN PHYSIOLOGY 2022. [DOI: 10.1016/j.cophys.2022.100591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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5
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Akkoc Y, Gozuacik D. Autophagy and Hepatic Tumor Microenvironment Associated Dormancy. J Gastrointest Cancer 2021; 52:1277-1293. [PMID: 34921672 DOI: 10.1007/s12029-021-00774-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2021] [Indexed: 02/08/2023]
Abstract
The goal of successful cancer treatment is targeting the eradication of cancer cells. Although surgical removal of the primary tumors and several rounds of chemo- and radiotherapy reduce the disease burden, in some cases, asymptomatic dormant cancer cells may still exist in the body. Dormant cells arise from the disseminated tumor cells (DTCs) from the primary lesion. DTCs escape from immune system and cancer therapy and reside at the secondary organ without showing no sign of proliferation. However, under some conditions. dormant cells can be re-activated and enter a proliferative state even after decades. As a stress response mechanism, autophagy may help the adaptation of DTCs at this futile foreign microenvironment and may control the survival and re-activation of dormant cells. Studies indicate that hepatic microenvironment serves a favorable condition for cancer cell dormancy. Although, no direct study was pointing out the role of autophagy in liver-assisted dormancy, involvement of autophagy in both liver microenvironment, health, and disease conditions has been indicated. Therefore, in this review article, we will summarize cancer dormancy and discuss the role and importance of autophagy and hepatic microenvironment in this context.
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Affiliation(s)
- Yunus Akkoc
- Koç University Research Centre for Translational Medicine (KUTTAM), Istanbul, 34010, Turkey.
| | - Devrim Gozuacik
- Koç University Research Centre for Translational Medicine (KUTTAM), Istanbul, 34010, Turkey.,Koç University School of Medicine, Istanbul, 34010, Turkey
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6
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Kaushik S, Tasset I, Arias E, Pampliega O, Wong E, Martinez-Vicente M, Cuervo AM. Autophagy and the hallmarks of aging. Ageing Res Rev 2021; 72:101468. [PMID: 34563704 DOI: 10.1016/j.arr.2021.101468] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/12/2021] [Accepted: 09/20/2021] [Indexed: 12/13/2022]
Abstract
Autophagy, an essential cellular process that mediates degradation of proteins and organelles in lysosomes, has been tightly linked to cellular quality control for its role as part of the proteostasis network. The current interest in identifying the cellular and molecular determinants of aging, has highlighted the important contribution of malfunctioning of autophagy with age to the loss of proteostasis that characterizes all old organisms. However, the diversity of cellular functions of the different types of autophagy and the often reciprocal interactions of autophagy with other determinants of aging, is placing autophagy at the center of the aging process. In this work, we summarize evidence for the contribution of autophagy to health- and lifespan and provide examples of the bidirectional interplay between autophagic pathways and several of the so-called hallmarks of aging. This central role of autophagy in aging, and the dependence on autophagy of many geroprotective interventions, has motivated a search for direct modulators of autophagy that could be used to slow aging and extend healthspan. Here, we review some of those ongoing therapeutic efforts and comment on the potential of targeting autophagy in aging.
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7
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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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8
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Corbet GA, Wheeler JR, Parker R, Weskamp K. TDP43 ribonucleoprotein granules: physiologic function to pathologic aggregates. RNA Biol 2021; 18:128-138. [PMID: 34412568 DOI: 10.1080/15476286.2021.1963099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Ribonucleoprotein (RNP) assemblies are ubiquitous in eukaryotic cells and have functions throughout RNA transcription, splicing, and stability. Of the RNA-binding proteins that form RNPs, TAR DNA-binding protein of 43 kD (TDP43) is of particular interest due to its essential nature and its association with disease. TDP43 plays critical roles in RNA metabolism, many of which require its recruitment to RNP granules such as stress granules, myo-granules, and neuronal transport granules. Moreover, the presence of cytoplasmic TDP43-positive inclusions is a pathological hallmark of several neurodegenerative diseases. Despite the pervasiveness of TDP43 aggregates, TDP43 mutations are exceedingly rare, suggesting that aggregation may be linked to dysregulation of TDP43 function. Oligomerization is a part of normal TDP43 function; thus, it is of interest to understand what triggers the irreversible aggregation that is seen in disease. Herein, we examine TDP43 functions, particularly in RNP granules, and the mechanisms which may explain pathological TDP43 aggregation.
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Affiliation(s)
- Giulia Ada Corbet
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | | | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Department of Chemistry, Howard Hughes Medical Institute, Chevy Chase, MD, USA
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9
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Cao X, Jin X, Liu B. The involvement of stress granules in aging and aging-associated diseases. Aging Cell 2020; 19:e13136. [PMID: 32170904 PMCID: PMC7189987 DOI: 10.1111/acel.13136] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Stress granules (SGs) are nonmembrane assemblies formed in cells in response to stress conditions. SGs mainly contain untranslated mRNA and a variety of proteins. RNAs and scaffold proteins with intrinsically disordered regions or RNA-binding domains are essential for the assembly of SGs, and multivalent macromolecular interactions among these components are thought to be the driving forces for SG assembly. The SG assembly process includes regulation through post-translational modification and involvement of the cytoskeletal system. During aging, many intracellular bioprocesses become disrupted by factors such as cellular environmental changes, mitochondrial dysfunction, and decline in the protein quality control system. Such changes could lead to the formation of aberrant SGs, as well as alterations in their maintenance, disassembly, and clearance. These aberrant SGs might in turn promote aging and aging-associated diseases. In this paper, we first review the latest progress on the molecular mechanisms underlying SG assembly and SG functioning under stress conditions. Then, we provide a detailed discussion of the relevance of SGs to aging and aging-associated diseases.
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Affiliation(s)
- Xiuling Cao
- State Key Laboratory of Subtropical Silviculture School of Forestry and Biotechnology Zhejiang A&F University Hangzhou China
| | - Xuejiao Jin
- State Key Laboratory of Subtropical Silviculture School of Forestry and Biotechnology Zhejiang A&F University Hangzhou China
| | - Beidong Liu
- State Key Laboratory of Subtropical Silviculture School of Forestry and Biotechnology Zhejiang A&F University Hangzhou China
- Department of Chemistry and Molecular Biology University of Gothenburg Goteborg Sweden
- Center for Large‐scale Cell‐based Screening Faculty of Science University of Gothenburg Goteborg Sweden
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10
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Buford TW, Manini TM, Kairalla JA, McDermott MM, Vaz Fragoso CA, Chen H, Fielding RA, King AC, Newman AB, Tranah GJ. Mitochondrial DNA Sequence Variants Associated With Blood Pressure Among 2 Cohorts of Older Adults. J Am Heart Assoc 2019; 7:e010009. [PMID: 30371200 PMCID: PMC6222953 DOI: 10.1161/jaha.118.010009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Background Age‐related changes in blood pressure are associated with a variety of poor health outcomes. Genetic factors are proposed contributors to age‐related increases in blood pressure, but few genetic loci have been identified. We examined the role of mitochondrial genomic variation in blood pressure by sequencing the mitochondrial genome. Methods and Results Mitochondrial DNA (mtDNA) data from 1755 participants from the LIFE (Lifestyle Interventions and Independence for Elders) studies and 788 participants from the Health ABC (Health, Aging, and Body Composition) study were evaluated using replication analysis followed by meta‐analysis. Participants were aged ≥69 years, of diverse racial backgrounds, and assessed for systolic blood pressure (SBP), diastolic blood pressure, and mean arterial pressure. After meta‐analysis across the LIFE and Health ABC studies, statistically significant associations of mtDNA variants with higher SBP (m.3197T>C, 16S rRNA; P=0.0005) and mean arterial pressure (m.15924A>G, t‐RNA‐thr; P=0.004) were identified in white participants. Among black participants, statistically significant associations with higher SBP (m.93A>G, HVII; m.16183A>C, HVI; both P=0.0001) and mean arterial pressure (m.16172T>C, HVI; m.16183A>C, HVI; m.16189T>C, HVI; m.12705C>T; all P's<0.0004) were observed. Significant pooled effects on SBP were observed across all transfer RNA regions (P=0.0056) in white participants. The individual and aggregate variant results are statistically significant after multiple comparisons adjustment for the number of mtDNA variants and mitochondrial regions examined. Conclusions These results suggest that mtDNA‐encoded variants are associated with variation in SBP and mean arterial pressure among older adults. These results may help identify mitochondrial activities to explain differences in blood pressure in older adults and generate new hypotheses surrounding mtDNA variation and the regulation of blood pressure. Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifiers: NCT01072500 and NCT00116194.
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Affiliation(s)
- Thomas W Buford
- 1 Department of Medicine University of Alabama at Birmingham AL
| | - Todd M Manini
- 2 Department of Aging and Geriatric Research University of Florida Gainesville FL
| | - John A Kairalla
- 3 Department of Biostatistics University of Florida Gainesville FL
| | - Mary M McDermott
- 4 Department of Medicine and Preventive Medicine Northwestern University Feinberg School of Medicine Chicago IL
| | | | - Haiying Chen
- 7 Department of Biostatistical Sciences Wake Forest School of Medicine Winston-Salem NC
| | - Roger A Fielding
- 8 Jean Mayer USDA Human Nutrition Research Center on Aging Tufts University Boston MA
| | - Abby C King
- 9 Department of Health Research and Policy and Stanford Prevention Research Center Stanford University Stanford CA
| | - Anne B Newman
- 10 Department of Epidemiology University of Pittsburgh PA
| | - Gregory J Tranah
- 11 California Pacific Medical Center Research Institute, San Francisco San Francisco CA
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11
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Li Y, Ruan DY, Jia CC, Zheng J, Wang GY, Zhao H, Yang Q, Liu W, Yi SH, Li H, Wang GS, Yang Y, Chen GH, Zhang Q. Aging aggravates hepatic ischemia-reperfusion injury in mice by impairing mitophagy with the involvement of the EIF2α-parkin pathway. Aging (Albany NY) 2019; 10:1902-1920. [PMID: 30089704 PMCID: PMC6128434 DOI: 10.18632/aging.101511] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 07/28/2018] [Indexed: 02/07/2023]
Abstract
Hepatic ischemia-reperfusion (I/R) injury fundamentally influences the performance of aged liver grafts. The significance of mitophagy in the age dependence of sensitivity to I/R injury remains poorly understood. Here, we show that aging aggravated hepatic I/R injury with decreased mitophagy in mice. The enhancement of mitophagy resulted in significant protection against hepatic I/R injury. Parkin, an E3 ubiquitin ligase, was found depleted by I/R in aged livers. In oxygen-glucose deprivation reperfusion (OGD-Rep.)-treated L02 cells, parkin silencing impaired mitophagy and aggravated cell damage through a relative large mitochondrial membrane potential transition. The phosphorylation of the endoplasmic reticulum stress response protein EIF2α, which was also reduced in the aged liver, induced parkin expression both in vivo and vitro. Forty-six hepatic biopsy specimens from liver graft were collected 2 hours after complete revascularization, followed by immunohistochemical analyses. Parkin expression was negatively correlated to donor age and the peak level of aspartate aminotransferase within first week after liver transplantation. Our translational study demonstrates that aging aggravated hepatic I/R injury by impairing the age-dependent mitophagy function via an insufficient parkin expression and identifies a new strategy to evaluate the capacity of an aged liver graft in the process of I/R through the parkin expression.
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Affiliation(s)
- Yang Li
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China.,Guangdong Key laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China
| | - Dan-Yun Ruan
- Department of Medical Oncology, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China
| | - Chang-Chang Jia
- Department of Biotherapy, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China.,Guangdong Key laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China
| | - Jun Zheng
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China.,Guangdong Key laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China
| | - Guo-Ying Wang
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Hui Zhao
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Qing Yang
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Wei Liu
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China.,Guangdong Key laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China
| | - Shu-Hong Yi
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Hua Li
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Gen-Shu Wang
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Yang Yang
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Gui-Hua Chen
- Department of Liver Surgery and Liver Transplantation, Guangzhou Clinical Research and Translation Center for Liver Disease, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Qi Zhang
- Department of Biotherapy, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China.,Guangdong Key laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong 510630, China
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12
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Tang Z, Hu B, Zang F, Wang J, Zhang X, Chen H. Nrf2 drives oxidative stress-induced autophagy in nucleus pulposus cells via a Keap1/Nrf2/p62 feedback loop to protect intervertebral disc from degeneration. Cell Death Dis 2019; 10:510. [PMID: 31263165 PMCID: PMC6602960 DOI: 10.1038/s41419-019-1701-3] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 12/19/2022]
Abstract
Intervertebral disc (IVD) degeneration is known to aggravate with age and oxidative stress is implicated in the pathogenesis of many age-related diseases. Nuclear factor (erythroid-derived-2)-like 2 (Nrf2) can confer adaptive protection against oxidative and proteotoxic stress in cells. In this study, we assessed whether Nrf2 can protect against oxidative stress in nucleus pulposus (NP) cells. In addition, we investigated Nrf2 expression in NP tissue samples from patients with different degrees of IVD degeneration and a mouse model of aging and IVD degeneration and the influence of H2O2-induced oxidative stress on autophagic pathways in NP cells. Autophagy was assessed by measuring levels of autophagy-related protein (ATG) family members and the autophagic markers, p62 and LC3. We found that expression of Nrf2 progressively decreased in human NP tissue samples of patients with increasing degrees of IVD degeneration. Nrf2 deficiency leads to the degeneration of IVDs during aging. Nrf2 knockout also aggravates IVD degeneration and reduces autophagic gene expression in an induced mouse model of IVD degeneration. The detrimental effects of H2O2-induced oxidative stress were increased in autophagy-deficient cells via reduced expression of Atg7 and the Keap1–Nrf2–p62 autophagy pathway. Taken together, these results suggest that excessive oxidative stress causes the upregulation of autophagy, and autophagy acts as an antioxidant feedback response activated by a Keap1-Nrf2-p62 feedback loop in IVD degeneration.
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Affiliation(s)
- Zehan Tang
- Department of Spinal Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Bo Hu
- Department of Spinal Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Fazhi Zang
- Department of Spinal Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Jianxi Wang
- Department of Spinal Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Xingda Zhang
- Department of Spinal Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Huajiang Chen
- Department of Spinal Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China.
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13
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Sampaio-Marques B, Ludovico P. Linking cellular proteostasis to yeast longevity. FEMS Yeast Res 2019; 18:4970764. [PMID: 29800380 DOI: 10.1093/femsyr/foy043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/12/2018] [Indexed: 12/19/2022] Open
Abstract
Proteostasis is a cellular housekeeping process that refers to the healthy maintenance of the cellular proteome that governs the fate of proteins from synthesis to degradation. Perturbations of proteostasis might result in protein dysfunction with consequent deleterious effects that can culminate in cell death. To deal with the loss of proteostasis, cells are supplied with a highly sophisticated and interconnected network that integrates as major players the molecular chaperones and the protein degradation pathways. It is well recognized that the ability of cells to maintain proteostasis declines during ageing, although the precise mechanisms are still elusive. Indeed, genetic or pharmacological enhancement of the proteostasis network has been shown to extend lifespan in a variety of ageing models. Therefore, an improved understanding of the interventions/mechanisms that contribute to cellular protein quality control will have a huge impact on the ageing field. This mini-review centers on the current knowledge about the major pathways that contribute for the maintenance of Saccharomyces cerevisiae proteostasis, with particular emphasis on the developments that highlight the multidimensional nature of the proteostasis network in the maintenance of proteostasis, as well as the age-dependent changes on this network.
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Affiliation(s)
- Belém Sampaio-Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Paula Ludovico
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
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14
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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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15
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Chi HC, Tsai CY, Tsai MM, Yeh CT, Lin KH. Molecular functions and clinical impact of thyroid hormone-triggered autophagy in liver-related diseases. J Biomed Sci 2019; 26:24. [PMID: 30849993 PMCID: PMC6407245 DOI: 10.1186/s12929-019-0517-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 02/26/2019] [Indexed: 02/07/2023] Open
Abstract
The liver is controlled by several metabolic hormones, including thyroid hormone, and characteristically displays high lysosomal activity as well as metabolic stress-triggered autophagy, which is stringently regulated by the levels of hormones and metabolites. Hepatic autophagy provides energy through catabolism of glucose, amino acids and free fatty acids for starved cells, facilitating the generation of new macromolecules and maintenance of the quantity and quality of cellular organelles, such as mitochondria. Dysregulation of autophagy and defective mitochondrial homeostasis contribute to hepatocyte injury and liver-related diseases, such as non-alcoholic fatty liver disease (NAFLD) and liver cancer. Thyroid hormones (TH) mediate several critical physiological processes including organ development, cell differentiation, metabolism and cell growth and maintenance. Accumulating evidence has revealed dysregulation of cellular TH activity as the underlying cause of several liver-related diseases, including alcoholic or non-alcoholic fatty liver disease and liver cancer. Data from epidemiologic, animal and clinical studies collectively support preventive functions of THs in liver-related diseases, highlighting the therapeutic potential of TH analogs. Elucidation of the molecular mechanisms and downstream targets of TH should thus facilitate the development of therapeutic strategies for a number of major public health issues. Here, we have reviewed recent studies focusing on the involvement of THs in hepatic homeostasis through induction of autophagy and their implications in liver-related diseases. Additionally, the potential underlying molecular pathways and therapeutic applications of THs in NAFLD and HCC are discussed.
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Affiliation(s)
- Hsiang-Cheng Chi
- Radiation Biology Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Chung-Ying Tsai
- Kidney Research Center and Department of Nephrology, Chang Gung Immunology Consortium, Chang Gung Memorial Hospital, Taoyuan, 333, Taiwan
| | - Ming-Ming Tsai
- Department of Nursing, Chang-Gung University of Science and Technology, Taoyuan, Taiwan, 333.,Department of General Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan, 613.,Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology , Taoyuan, Taiwan
| | - Chau-Ting Yeh
- Liver Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan, 333
| | - Kwang-Huei Lin
- Liver Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan, 333. .,Department of Biochemistry, College of Medicine, Chang-Gung University, 259 Wen-Hwa 1 Road, Taoyuan, 333, Taiwan, Republic of China. .,Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology , Taoyuan, Taiwan.
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16
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Abstract
The autophagic machinery is a well-conserved degradation system in eukaryotes from yeast to mammals. Autophagy has been thought of as a nonselective degradation process in which cytoplasmic proteins and organelles are degraded by fusion with lysosome. Recent studies have revealed selective forms of autophagy, such as mitochondria-specific autophagy, termed "mitophagy". Research over the past decade has revealed that autophagy in cardiomyocytes plays a protective role, not only during hemodynamic stress but in homeostasis during aging. Hemodynamic stress and aging induce mitochondrial damage, leading to increased oxidative stress and decreased ATP production. Damaged mitochondria are generally degraded through mitophagy, which might be the main protective function of autophagy in the heart. Complete digestion of mitochondrial DNA through mitophagy is important to avoid inflammatory responses that can induce heart failure. A polyamine, spermidine, is reported to bring about an extension of lifespan and to protect the heart from age-related cardiac dysfunction, both of which are mediated through induction of autophagy. Therefore, appropriate induction of autophagy could be a novel therapeutic target for cardiovascular diseases, including heart failure. However, precise evaluation of autophagic activity in the human heart is difficult at this time, but exploitation of the novel technique of autophagy evaluation is expected for both drug discovery and clinical application.
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Affiliation(s)
- Osamu Yamaguchi
- Department of Cardiology, Pulmonology, Hypertension & Nephrology, Ehime University Graduate School of Medicine
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17
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Xu J, Jiao K, Liu X, Sun Q, Wang K, Xu H, Zhang S, Wu Y, Wu L, Liu D, Wang W, Liu H. Omi/HtrA2 Participates in Age-Related Autophagic Deficiency in Rat Liver. Aging Dis 2018; 9:1031-1042. [PMID: 30574416 PMCID: PMC6284766 DOI: 10.14336/ad.2018.0221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 02/21/2018] [Indexed: 12/16/2022] Open
Abstract
Liver is a vital organ with many important functions, and the maintenance of normal hepatic function is necessary for health. As an essential mechanism for maintaining cellular homeostasis, autophagy plays an important role in ensuring normal organ function. Studies have indicated that the degeneration of hepatic function is associated with autophagic deficiency in aging liver. However, the underlying mechanisms still remain unclear. The serine protease Omi/HtrA2 belongs to the HtrA family and promotes apoptosis through either the caspase-dependent or caspase-independent pathway. Mice lacking Omi/HtrA2 exhibited progeria symptoms (premature aging), which were similar to the characteristics of autophagic insufficiency. In this study, we demonstrated that both the protein level of Omi/HtrA2 in liver and hepatic function were reduced as rats aged, and there was a positive correlation between them. Furthermore, several autophagy-related proteins (LC3II/I, Beclin-1 and LAMP2) in rat liver were decreased significantly with the increasing of age. Finally, inhibition of Omi/HtrA2 resulted in reduced autophagy and hepatic dysfunction. In conclusion, these results suggest that Omi/HtrA2 participates in age-related autophagic deficiency in rat liver. This study may offer a novel insight into the mechanism involved in liver aging.
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Affiliation(s)
- Jiahui Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Kun Jiao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Xin Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Qi Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Ke Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Haibo Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Shangyue Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Ye Wu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Linguo Wu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Dan Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Wen Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Huirong Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
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18
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Vaz Fragoso CA, Manini TM, Kairalla JA, Buford TW, Hsu FC, Gill TM, Kritchevsky SB, McDermott MM, Sanders JL, Cummings SR, Tranah GJ. Mitochondrial DNA variants and pulmonary function in older persons. Exp Gerontol 2018; 115:96-103. [PMID: 30508565 DOI: 10.1016/j.exger.2018.11.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 11/01/2018] [Accepted: 11/28/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND We provide the first examination of mitochondrial DNA (mtDNA) variants and pulmonary function in older persons. METHODS Cross-sectional associations between mtDNA variants and pulmonary function were evaluated as a combined p-values meta-analysis, using data from two independent cohorts of older persons. The latter included white and black participants, aged ≥70 years, from the Lifestyle Interventions and Independence for Elders study (LIFE) (N = 1247) and the Health, Aging and Body Composition study (Health ABC) (N = 731), respectively. Pulmonary function included the forced expiratory volume in one-second as a Z-score (FEV1z) and the maximal inspiratory pressure (MIP) in cm of water. RESULTS In black participants, significant associations were found between mtDNA variants and MIP: m.7146A > G, COI (p = 3E-5); m.7389 T > C, COI (p = 2E-4); m.15301G > A, CYB (p = 9E-5); m.16265A > G, HV1 (p = 9E-5); meta-analytical p-values <0.0002. Importantly, these mtDNA variants were unique to black participants and were not present in white participants. Moreover, in black participants, aggregate genetic effects on MIP were observed across mutations in oxidative phosphorylation complex IV (p = 0.004), complex V (p = 0.0007), and hypervariable (p = 0.003) regions. The individual and aggregate variant results were significant after adjustment for multiple comparisons. Otherwise, no significant associations were detected for MIP in whites or for FEV1z in whites or blacks. CONCLUSIONS We have shown that mtDNA variants of African origin are cross-sectionally associated with MIP, a measure of respiratory muscle strength. Thus, our results establish the rationale for longitudinal studies to evaluate whether mtDNA variants of African origin identify those at risk of subsequently developing a respiratory muscle impairment (lower MIP values).
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Affiliation(s)
- Carlos A Vaz Fragoso
- Yale School of Medicine, Department of Medicine, New Haven, CT, United States of America; Veterans Affairs Connecticut Healthcare System, Department of Medicine, West Haven, CT, United States of America.
| | - Todd M Manini
- University of Florida, Department of Aging and Geriatric Research, Gainesville, FL, United States of America
| | - John A Kairalla
- University of Florida, Department of Biostatistics, Gainesville, FL, United States of America
| | - Thomas W Buford
- University of Alabama at Birmingham, Department of Medicine, Birmingham, AL, United States of America
| | - Fang-Chi Hsu
- Wake Forest School of Medicine, Department of Biostatistical Sciences, Winston-Salem, NC, United States of America
| | - Thomas M Gill
- Yale School of Medicine, Department of Medicine, New Haven, CT, United States of America
| | - Stephen B Kritchevsky
- Wake Forest School of Medicine, Sticht Center for Healthy Aging and Alzheimer's Prevention, Winston-Salem, NC, United States of America
| | - Mary M McDermott
- Northwestern University, Feinberg School of Medicine, Chicago, IL, United States of America
| | - Jason L Sanders
- Massachusetts General Hospital, Department of Medicine, Boston, MA, United States of America
| | - Steven R Cummings
- California Pacific Medical Center Research Institute, San Francisco, CA, United States of America
| | - Gregory J Tranah
- California Pacific Medical Center Research Institute, San Francisco, CA, United States of America
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19
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Manini TM, Buford TW, Kairalla JA, McDermott MM, Vaz Fragoso CA, Fielding RA, Hsu FC, Johannsen N, Kritchevsky S, Harris TB, Newman AB, Cummings SR, King AC, Pahor M, Santanasto AJ, Tranah GJ. Meta-analysis identifies mitochondrial DNA sequence variants associated with walking speed. GeroScience 2018; 40:497-511. [PMID: 30338417 DOI: 10.1007/s11357-018-0043-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/06/2018] [Indexed: 12/25/2022] Open
Abstract
Declines in walking speed are associated with a variety of poor health outcomes including disability, comorbidity, and mortality. While genetic factors are putative contributors to variability in walking, few genetic loci have been identified for this trait. We examined the role of mitochondrial genomic variation on walking speed by sequencing the entire mitochondrial DNA (mtDNA). Data were meta-analyzed from 1758 Lifestyle Interventions and Independence for Elders (LIFE) Study and replication data from 730 Health, Aging, and Body Composition (HABC) Study participants with baseline walking speed information. Participants were 69+ years old of diverse racial backgrounds (African, European, and other race/ethnic groups) and had a wide range of mean walking speeds [4-6 m (0.78-1.09 m/s) and 400 m (0.83-1.24 m/s)]. Meta-analysis across studies and racial groups showed that m.12705C>T, ND5 variant was significantly associated (p < 0.0001) with walking speed at both short and long distances. Replication and meta-analysis also identified statistically significant walking speed associations (p < 0.0001) between the m.5460.G>A, ND2 and m.309C>CT, HV2 variants at short and long distances, respectively. All results remained statistically significant after multiple comparisons adjustment for 499 mtDNA variants. The m.12705C>T variant can be traced to the beginnings of human global migration and that cells carrying this variant display altered tRNA expression. Significant pooled effects related to stopping during the long-distance walk test were observed across OXPHOS complexes I (p = 0.0017) and III (p = 0.0048). These results suggest that mtDNA-encoded variants are associated with differences in walking speed among older adults, potentially identifying those at risk of developing mobility impairments.
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Affiliation(s)
- Todd M Manini
- Department of Aging and Geriatric Research, University of Florida, 2004 Mowry Rd., Gainesville, FL, 32611, USA.
| | - Thomas W Buford
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - John A Kairalla
- Department of Biostatistics, University of Florida, Gainesville, FL, USA
| | - Mary M McDermott
- General Internal Medicine and Geriatrics and Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Carlos A Vaz Fragoso
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Roger A Fielding
- Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Fang-Chi Hsu
- The Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Neil Johannsen
- Preventive Medicine Department, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Stephen Kritchevsky
- Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Tamara B Harris
- Intramural Research Program, Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Bethesda, MD, USA
| | - Anne B Newman
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Steven R Cummings
- California Pacific Medical Center Research Institute, San Francisco, CA, 94107, USA
| | - Abby C King
- Department of Health Research and Policy - Epidemiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Marco Pahor
- Department of Aging and Geriatric Research, University of Florida, 2004 Mowry Rd., Gainesville, FL, 32611, USA
| | - Adam J Santanasto
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Gregory J Tranah
- California Pacific Medical Center Research Institute, San Francisco, CA, 94107, USA.
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20
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McCormick JJ, VanDusseldorp TA, Ulrich CG, Lanphere RL, Dokladny K, Mosely PL, Mermier CM. The effect of aging on the autophagic and heat shock response in human peripheral blood mononuclear cells. Physiol Int 2018; 105:247-256. [PMID: 30269563 DOI: 10.1556/2060.105.2018.3.20] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Autophagy is a lysosome degradation pathway through which damaged organelles and macromolecules are degraded within the cell. A decrease in activity of the autophagic process has been linked to several age-associated pathologies, including triglyceride accumulation, mitochondrial dysfunction, muscle degeneration, and cardiac malfunction. Here, we examined the differences in the autophagic response using autophagy-inducer rapamycin (Rapa) in peripheral blood mononuclear cells (PBMCs) from young (21.8 ± 1.9 years) and old (64.0 ± 3.7 years) individuals. Furthermore, we tested the interplay between the heat shock response and autophagy systems. Our results showed a significant increase in LC3-II protein expression in response to Rapa treatment in young but not in old individuals. This was associated with a decreased response in MAP1LC3B mRNA levels, but not SQSTM1/p62. Furthermore, HSPA1A mRNA was upregulated only in young individuals, despite no differences in HSP70 protein expression. The combined findings suggest a suppressed autophagic response following Rapa treatment in older individuals.
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Affiliation(s)
- J J McCormick
- 1 Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
| | - T A VanDusseldorp
- 1 Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA.,2 Department of Exercise Science and Sport Management, Kennesaw State University , Kennesaw, GA, USA
| | - C G Ulrich
- 1 Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
| | - R L Lanphere
- 3 Department of Kinesiology & Health Promotion, University of Kentucky , Lexington, KY, USA
| | - K Dokladny
- 4 Department of Internal Medicine, University of New Mexico , Albuquerque, NM, USA
| | - P L Mosely
- 5 Departments of Medicine and Biomedical Informatics, University of Arkansas for Medical Sciences , Little Rock, AR, USA
| | - C M Mermier
- 1 Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
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21
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Caprara G. Diet and longevity: The effects of traditional eating habits on human lifespan extension. MEDITERRANEAN JOURNAL OF NUTRITION AND METABOLISM 2018. [DOI: 10.3233/mnm-180225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Since the dawn of time human beings have been trying to improve the quality of the existence and extend their lifespan. Genetic, environmental, behavioral and dietary factors influence the pathways that regulate aging and life expectancy, thus rendering longevity a very complex phenomenon. Although a long-lived elixir has not yet been found, physicians and scientists agree that nutrition has a major impact on the overall mortality and morbidity, hence becoming the subject of a widespread scientific research. This review describes, analyzes and compares the effects of different types of diets in reducing the onset of typical Western countries non-communicable diseases (NCDs) (cardiovascular diseases, tumors, chronic respiratory diseases, diabetes, etc.), thus increasing the average lifespan. It will first depict the most relevant characteristics, nutraceutical properties and effects on the populations of the Mediterranean, Japanese, Vegetarian and New Nordic Diet. Finally, it will describe the impact of different dietary restrictions in modulating the genetic pathways that regulate metabolism and aging. Overall, this work reinforces the evidence that specific eating habits, in addition to healthy and active lifestyles, are crucial to increase people’s health span and to achieve an optimal longevity.
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Affiliation(s)
- Greta Caprara
- Department of Experimental Oncology, European Institute of Oncology (IEO), Via Adamello 16, 20139 Milan, Italy
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22
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23
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Hansen M, Rubinsztein DC, Walker DW. Autophagy as a promoter of longevity: insights from model organisms. Nat Rev Mol Cell Biol 2018; 19:579-593. [PMID: 30006559 DOI: 10.1038/s41580-018-0033-y] [Citation(s) in RCA: 463] [Impact Index Per Article: 77.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Autophagy is a conserved process that catabolizes intracellular components to maintain energy homeostasis and to protect cells against stress. Autophagy has crucial roles during development and disease, and evidence accumulated over the past decade indicates that autophagy also has a direct role in modulating ageing. In particular, elegant studies using yeasts, worms, flies and mice have demonstrated a broad requirement for autophagy-related genes in the lifespan extension observed in a number of conserved longevity paradigms. Moreover, several new and interesting concepts relevant to autophagy and its role in modulating longevity have emerged. First, select tissues may require or benefit from autophagy activation in longevity paradigms, as tissue-specific overexpression of single autophagy genes is sufficient to extend lifespan. Second, selective types of autophagy may be crucial for longevity by specifically targeting dysfunctional cellular components and preventing their accumulation. And third, autophagy can influence organismal health and ageing even non-cell autonomously, and thus, autophagy stimulation in select tissues can have beneficial, systemic effects on lifespan. Understanding these mechanisms will be important for the development of approaches to improve human healthspan that are based on the modulation of autophagy.
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Affiliation(s)
- Malene Hansen
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging and Regeneration, La Jolla, CA, USA.
| | - David C Rubinsztein
- Cambridge Institute for Medical Research, Department of Medical Genetics, Cambridge, UK. .,UK Dementia Research Institute, University of Cambridge, Cambridge, UK.
| | - David W Walker
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA. .,Molecular Biology Institute, University of California, Los Angeles, CA, USA.
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24
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Induction of nuclear factor-κB signal-mediated apoptosis and autophagy by reactive oxygen species is associated with hydrogen peroxide-impaired growth performance of broilers. Animal 2018; 12:2561-2570. [PMID: 29720292 DOI: 10.1017/s1751731118000903] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The oxidative study has always been particularly topical in poultry science. However, little information about the occurrence of cellular apoptosis and autophagy through the reactive oxygen species (ROS) generation in nuclear factor-κB (NF-κB) signal pathway was reported in the liver of broilers exposed to hydrogen peroxide (H2O2). So we investigated the change of growth performance of broilers exposed to H2O2 and further explored the occurrence of apoptosis and autophagy, as well as the expression of NF-κB in these signaling pathways in the liver. A total of 320 1-day-old Arbor Acres male broiler chickens were raised on a basal diet and randomly divided into five treatments which were arranged as non-injected treatment (Control), physiological saline (0.75%) injected treatment (Saline) and H2O2 treatments (H2O2(0.74), H2O2(1.48) and H2O2(2.96)) received an intraperitoneal injection of H2O2 with 0.74, 1.48 and 2.96 mM/kg BW. The results showed that compared to those in the control and saline treatments, 2.96 mM/kg BW H2O2-treated broilers exhibited significantly higher feed/gain ratio at 22 to 42 days and 1 to 42 days, ROS formation, the contents of oxidation products, the mRNA expressions of caspases (3, 6, 8), microtubule-associated protein 1 light chain 3 (LC3)-II/LC3-I, autophagy-related gene 6, Bcl-2 associated X and protein expressions of total caspase-3 and total LC3-II, and significantly lower BW gain at 22 to 42 days and 1 to 42 days, the activities of total superoxide dismutase and glutathione peroxidase, the expression of NF-κB in the liver. Meanwhile, significantly higher feed/gain ratio at 1 to 42 days, ROS formation, the contents of protein carbonyl and malondialdehyde, the mRNA expression of caspase-3 and the protein expressions of total caspase-3 and total LC3-II, as well as significantly lower BW gain at 22 to 42 days and 1 to 42 days were observed in broilers received 1.48 mM/kg BW H2O2 treatment than those in control and saline treatments. These results indicated that oxidative stress induced by H2O2 had a negative effect on histomorphology and redox status in the liver of broilers, which was associated with a decline in growth performance of broilers. This may attribute to apoptosis and autophagy processes triggered by excessive ROS that suppress the NF-κB signaling pathway.
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Li C, White SH, Warren LK, Wohlgemuth SE. Skeletal muscle from aged American Quarter Horses shows impairments in mitochondrial biogenesis and expression of autophagy markers. Exp Gerontol 2018; 102:19-27. [DOI: 10.1016/j.exger.2017.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/27/2017] [Accepted: 11/30/2017] [Indexed: 12/19/2022]
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Kevei É, Pokrzywa W, Hoppe T. Repair or destruction-an intimate liaison between ubiquitin ligases and molecular chaperones in proteostasis. FEBS Lett 2017; 591:2616-2635. [PMID: 28699655 PMCID: PMC5601288 DOI: 10.1002/1873-3468.12750] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/04/2017] [Accepted: 07/06/2017] [Indexed: 12/11/2022]
Abstract
Cellular differentiation, developmental processes, and environmental factors challenge the integrity of the proteome in every eukaryotic cell. The maintenance of protein homeostasis, or proteostasis, involves folding and degradation of damaged proteins, and is essential for cellular function, organismal growth, and viability 1, 2. Misfolded proteins that cannot be refolded by chaperone machineries are degraded by specialized proteolytic systems. A major degradation pathway regulating cellular proteostasis is the ubiquitin (Ub)/proteasome system (UPS), which regulates turnover of damaged proteins that accumulate upon stress and during aging. Despite a large number of structurally unrelated substrates, Ub conjugation is remarkably selective. Substrate selectivity is mainly provided by the group of E3 enzymes. Several observations indicate that numerous E3 Ub ligases intimately collaborate with molecular chaperones to maintain the cellular proteome. In this review, we provide an overview of specialized quality control E3 ligases playing a critical role in the degradation of damaged proteins. The process of substrate recognition and turnover, the type of chaperones they team up with, and the potential pathogeneses associated with their malfunction will be further discussed.
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Affiliation(s)
- Éva Kevei
- School of Biological Sciences, University of Reading, Whiteknights, UK
| | - Wojciech Pokrzywa
- International Institute of Molecular and Cell Biology in Warsaw, Poland
| | - Thorsten Hoppe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Germany
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Chang JT, Kumsta C, Hellman AB, Adams LM, Hansen M. Spatiotemporal regulation of autophagy during Caenorhabditis elegans aging. eLife 2017; 6. [PMID: 28675140 PMCID: PMC5496740 DOI: 10.7554/elife.18459] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 06/04/2017] [Indexed: 12/20/2022] Open
Abstract
Autophagy has been linked to longevity in many species, but the underlying mechanisms are unclear. Using a GFP-tagged and a new tandem-tagged Atg8/LGG-1 reporter, we quantified autophagic vesicles and performed autophagic flux assays in multiple tissues of wild-type Caenorhabditis elegans and long-lived daf-2/insulin/IGF-1 and glp-1/Notch mutants throughout adulthood. Our data are consistent with an age-related decline in autophagic activity in the intestine, body-wall muscle, pharynx, and neurons of wild-type animals. In contrast, daf-2 and glp-1 mutants displayed unique age- and tissue-specific changes in autophagic activity, indicating that the two longevity paradigms have distinct effects on autophagy during aging. Although autophagy appeared active in the intestine of both long-lived mutants, inhibition of intestinal autophagy significantly abrogated lifespan extension only in glp-1 mutants. Collectively, our data suggest that autophagic activity normally decreases with age in C. elegans, whereas daf-2 and glp-1 long-lived mutants regulate autophagy in distinct spatiotemporal-specific manners to extend lifespan. DOI:http://dx.doi.org/10.7554/eLife.18459.001
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Affiliation(s)
- Jessica T Chang
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Caroline Kumsta
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Andrew B Hellman
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Linnea M Adams
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Malene Hansen
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
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Abstract
The concept of macroautophagy was established in 1963, soon after the discovery of lysosomes in rat liver. Over the 50 years since, studies of liver autophagy have produced many important findings. The liver is rich in lysosomes and possesses high levels of metabolic-stress-induced autophagy, which is precisely regulated by concentrations of hormones and amino acids. Liver autophagy provides starved cells with amino acids, glucose and free fatty acids for use in energy production and synthesis of new macromolecules, and also controls the quality and quantity of organelles such as mitochondria. Although the efforts of early investigators contributed markedly to our current knowledge of autophagy, the identification of autophagy-related genes represented a revolutionary breakthrough in our understanding of the physiological roles of autophagy in the liver. A growing body of evidence has shown that liver autophagy contributes to basic hepatic functions, including glycogenolysis, gluconeogenesis and β-oxidation, through selective turnover of specific cargos controlled by a series of transcription factors. In this Review, we outline the history of liver autophagy study, and then describe the roles of autophagy in hepatic metabolism under healthy and disease conditions, including the involvement of autophagy in α1-antitrypsin deficiency, NAFLD, hepatocellular carcinoma and viral hepatitis.
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Affiliation(s)
- Takashi Ueno
- Laboratory of Proteomics and Biomolecular Science, Research Support Center, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8510, Japan
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Go KL, Lee S, Behrns KE, Kim JS. Mitochondrial Damage and Mitophagy in Ischemia/Reperfusion-Induced Liver Injury. MOLECULES, SYSTEMS AND SIGNALING IN LIVER INJURY 2017:183-219. [DOI: 10.1007/978-3-319-58106-4_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Ntsapi C, Loos B. Caloric restriction and the precision-control of autophagy: A strategy for delaying neurodegenerative disease progression. Exp Gerontol 2016; 83:97-111. [DOI: 10.1016/j.exger.2016.07.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 07/18/2016] [Accepted: 07/25/2016] [Indexed: 01/07/2023]
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Telomerase deficiency delays renal recovery in mice after ischemia-reperfusion injury by impairing autophagy. Kidney Int 2015; 88:85-94. [PMID: 25760322 PMCID: PMC4490111 DOI: 10.1038/ki.2015.69] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 01/19/2015] [Accepted: 01/22/2015] [Indexed: 02/07/2023]
Abstract
The aged population suffers increased morbidity and higher mortality in response to episodes of acute kidney injury (AKI). Aging is associated with telomere shortening, and both telomerase reverse transcriptase (TerT) and RNA (TerC) are essential to maintain telomere length. To define a role of telomerase deficiency in susceptibility to AKI, we used ischemia/reperfusion injury in wild type mice or mice with either TerC or TerT deletion. Injury induced similar renal impairment at day 1 in each genotype, as assessed by azotemia, proteinuria, acute tubular injury score and apoptotic tubular epithelial cell index. However, either TerC or TerT knockout significantly delayed recovery compared to wild type mice. Electron microscopy showed increased autophagosome formation in renal tubular epithelial cells in wild type mice but a significant delay of their development in TerC and TerT knockout mice. There were also impeded increases in the expression of the autophagosome marker LC3 II, prolonged accumulation of the autophagosome protein P62, an increase of the cell cycle regulator p16, and greater activation of the mTOR pathway. The mTORC1 inhibitor, rapamycin, partially restored the ischemia/reperfusion-induced autophagy response, without a significant effect on either p16 induction or tubule epithelial cell proliferation. Thus, muting the maintenance of normal telomere length in mice impaired recovery from AKI, due to an increase in tubule cell senescence and impairment of mTOR-mediated autophagy.
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Seglen PO, Luhr M, Mills IG, Sætre F, Szalai P, Engedal N. Macroautophagic cargo sequestration assays. Methods 2015; 75:25-36. [DOI: 10.1016/j.ymeth.2014.12.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 12/17/2014] [Accepted: 12/31/2014] [Indexed: 11/27/2022] Open
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Saez I, Vilchez D. Protein clearance mechanisms and their demise in age-related neurodegenerative diseases. AIMS MOLECULAR SCIENCE 2015. [DOI: 10.3934/molsci.2015.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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34
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The role of protein clearance mechanisms in organismal ageing and age-related diseases. Nat Commun 2014; 5:5659. [DOI: 10.1038/ncomms6659] [Citation(s) in RCA: 442] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 10/24/2014] [Indexed: 12/27/2022] Open
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Katzman SM, Strotmeyer ES, Nalls MA, Zhao Y, Mooney S, Schork N, Newman AB, Harris TB, Yaffe K, Cummings SR, Liu Y, Tranah GJ. Mitochondrial DNA Sequence Variation Associated With Peripheral Nerve Function in the Elderly. J Gerontol A Biol Sci Med Sci 2014; 70:1400-8. [PMID: 25394619 DOI: 10.1093/gerona/glu175] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/19/2014] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Mitochondrial dysfunction is a prominent hallmark of many sensory neuropathies. The purpose of this study was to assess the influence of mitochondrial DNA sequence variation on peripheral nerve function in the population-based Health, Aging, and Body Composition Study. METHODS We investigated the role of common mitochondrial DNA variation (n = 1,580) and complete mitochondrial DNA sequences (n = 138) on peroneal motor nerve conduction velocity and amplitude, average vibration detection threshold, and monofilament sensitivity. RESULTS Nominal associations among common mitochondrial DNA variants and haplogroups were identified but were not statistically significant after adjustment for multiple comparisons. Sequence-based approaches were used to identify aggregate variant associations across the 16S rRNA (weighted-sum, p = 2E-05 and variable threshold, p = 9E-06) for nerve conduction velocity. Several of these rare 16S variants occurred at or near sites with earlier disease associations and are also in close proximity to the peptidyl transferase center, which is the catalytic center of the 16S rRNA CONCLUSIONS: These results suggest that sequence variation related to mitochondrial protein synthesis/assembly is associated with peripheral nerve function and may provide insight into targets for intervention or new clinical strategies to preserve nerve function in late life.
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Affiliation(s)
- Shana M Katzman
- Department of Innovation, Technology, and Alliances, University of California, San Francisco and
| | - Elsa S Strotmeyer
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania and
| | - Michael A Nalls
- Laboratory of Neurogenetics, Intramural Research Program, National Institute on Aging, Bethesda, Maryland and
| | - Yiqiang Zhao
- State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, China and
| | - Sean Mooney
- Department of Bioinformatics, Buck Institute for Research on Aging, Novato, California and
| | - Nik Schork
- Department of Human Biology, J. Craig Venter Institute, La Jolla, California and
| | - Anne B Newman
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania and
| | - Tamara B Harris
- Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, Maryland and
| | - Kristine Yaffe
- Departments of Psychiatry, Neurology, and Epidemiology, University of California, and Department of Geriatric Psychiatry, San Francisco VA Medical Center and
| | - Steven R Cummings
- California Pacific Medical Center Research Institute, San Francisco and
| | - Yongmei Liu
- Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Gregory J Tranah
- California Pacific Medical Center Research Institute, San Francisco and
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Cuervo AM, Macian F. Autophagy and the immune function in aging. Curr Opin Immunol 2014; 29:97-104. [PMID: 24929664 DOI: 10.1016/j.coi.2014.05.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 05/12/2014] [Accepted: 05/14/2014] [Indexed: 02/08/2023]
Abstract
Just when you thought that you had heard it all about autophagy-the conserved cellular process that mediates turnover of cellular constituents in the lysosomes - studies keep coming out highlighting new types of autophagy, new functions for autophagy or even new autophagy-independent roles for the proteins associated with this process. The field of immunology has been riding the autophagic wave since the beginning of its revival; first due to its role in the host defense against pathogens, and more recently through the better understanding of the unique characteristics and functions of different autophagic pathways in immune cells. Here, we describe some of these new functions that are tightening the connection between autophagy and acquired or innate immunity and their malfunctioning with age.
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Affiliation(s)
- Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
| | - Fernando Macian
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA; Institute for Aging Studies, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
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Current understanding of sarcopenia: possible candidates modulating muscle mass. Pflugers Arch 2014; 467:213-29. [PMID: 24797147 DOI: 10.1007/s00424-014-1527-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 04/21/2014] [Accepted: 04/22/2014] [Indexed: 12/17/2022]
Abstract
The world's elderly population is expanding rapidly, and we are now faced with the significant challenge of maintaining or improving physical activity, independence, and quality of life in the elderly. Sarcopenia, the age-related loss of skeletal muscle mass, is characterized by a deterioration of muscle quantity and quality leading to a gradual slowing of movement, a decline in strength and power, increased risk of fall-related injury, and often, frailty. Since sarcopenia is largely attributed to various molecular mediators affecting fiber size, mitochondrial homeostasis, and apoptosis, the mechanisms responsible for these deleterious changes present numerous therapeutic targets for drug discovery. Muscle loss has been linked with several proteolytic systems, including the ubuiquitin-proteasome, lysosome-autophagy, and tumor necrosis factor (TNF)-α/nuclear factor-kappaB (NF-κB) systems. Although many factors are considered to regulate age-dependent muscle loss, this gentle atrophy is not affected by factors known to enhance rapid atrophy (denervation, hindlimb suspension, etc.). In addition, defects in Akt-mammalian target of rapamycin (mTOR) and serum response factor (SRF)-dependent signaling have been found in sarcopenic muscle. Intriguingly, more recent studies indicated an apparent functional defect in autophagy- and myostatin-dependent signaling in sarcopenic muscle. In this review, we summarize the current understanding of the adaptation of many regulators in sarcopenia.
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Pyo JO, Yoo SM, Ahn HH, Nah J, Hong SH, Kam TI, Jung S, Jung YK. Overexpression of Atg5 in mice activates autophagy and extends lifespan. Nat Commun 2014; 4:2300. [PMID: 23939249 PMCID: PMC3753544 DOI: 10.1038/ncomms3300] [Citation(s) in RCA: 500] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 07/12/2013] [Indexed: 01/06/2023] Open
Abstract
Autophagy has been implicated in the ageing process, but whether autophagy activation extends lifespan in mammals is unknown. Here we show that ubiquitous overexpression of Atg5, a protein essential for autophagosome formation, extends median lifespan of mice by 17.2%. We demonstrate that moderate overexpression of Atg5 in mice enhances autophagy, and that Atg5 transgenic mice showed anti-ageing phenotypes, including leanness, increased insulin sensitivity and improved motor function. Furthermore, mouse embryonic fibroblasts cultured from Atg5 transgenic mice are more tolerant to oxidative damage and cell death induced by oxidative stress, and this tolerance was reversible by treatment with an autophagy inhibitor. Our observations suggest that the leanness and lifespan extension in Atg5 transgenic mice may be the result of increased autophagic activity. Changes in autophagy have been shown to modulate lifespan in lower organisms. Here, Pyo et al. show that mice globally overexpressing the autophagy protein Atg5 live longer and are leaner than normal mice, providing the first evidence that increased autophagy extends lifespan in mammals.
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Affiliation(s)
- Jong-Ok Pyo
- Global Research Laboratory, School of Biological Sciences/Bio-MAX Institute, Seoul National University, Seoul 151-747, Korea
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The interplay between autophagy and mitochondrial dysfunction in oxidative stress-induced cardiac aging and pathology. J Mol Cell Cardiol 2014; 71:62-70. [PMID: 24650874 DOI: 10.1016/j.yjmcc.2014.03.007] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 03/08/2014] [Accepted: 03/10/2014] [Indexed: 12/19/2022]
Abstract
Aging is accompanied by a progressive increase in the incidence and prevalence of cardiovascular disease (CVD). Prolonged exposure to cardiovascular risk factors, together with intrinsic age-dependent declines in cardiac functionality, increases the vulnerability of the heart to both endogenous and exogenous stressors, ultimately enhancing the susceptibility to developing CVD in late life. Both increased levels of oxidative damage and the accumulation of dysfunctional mitochondria have been observed in a wide range of cardiac diseases, which may therefore represent a common ground upon which many aspects of CVD develop. In this review, we summarize the current knowledge on the mechanisms whereby oxidative stress arising from mitochondrial dysfunction is involved in the process of cardiac aging and in the pathogenesis of CVD highly prevalent in late life (e.g., heart failure and ischemic heart disease). Special emphasis is placed on recent evidence about the role played by alterations in cellular quality control systems, in particular autophagy/mitophagy and mitochondrial dynamics (fusion and fission), and their interconnections in the context of age-related CVD. Cardioprotective interventions acting through the modulation of mitochondrial autophagy (calorie restriction, calorie restriction mimetics, and the gasotransmitter hydrogen sulfide) are also presented. This article is part of a Special Issue entitled "Protein Quality Control, the Ubiquitin Proteasome System, and Autophagy".
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Gohlke S, Mishto M, Textoris-Taube K, Keller C, Giannini C, Vasuri F, Capizzi E, D’Errico-Grigioni A, Kloetzel PM, Dahlmann B. Molecular alterations in proteasomes of rat liver during aging result in altered proteolytic activities. AGE (DORDRECHT, NETHERLANDS) 2014; 36:57-72. [PMID: 23690132 PMCID: PMC3889881 DOI: 10.1007/s11357-013-9543-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 05/08/2013] [Indexed: 06/02/2023]
Abstract
Aging induces alterations of tissue protein homoeostasis. To investigate one of the major systems catalysing intracellular protein degradation we have purified 20S proteasomes from rat liver of young (2 months) and aged (23 months) animals and separated them into three subpopulations containing different types of intermediate proteasomes with standard- and immuno-subunits. The smallest subpopulation ΙΙΙ and the major subpopulation Ι comprised proteasomes containing immuno-subunits β1i and β5i beside small amounts of standard-subunits, whereas proteasomes of subpopulation ΙΙ contained only β5i beside standard-subunits. In favour of a relative increase of the major subpopulation Ι, subpopulation ΙΙ and ΙΙΙ were reduced for about 55 % and 80 %, respectively, in aged rats. Furthermore, in all three 20S proteasome subpopulations from aged animals standard-active site subunits were replaced by immuno-subunits. Overall, this transformation resulted in a relative increase of immuno-subunit-containing proteasomes, paralleled by reduced activity towards short fluorogenic peptide substrates. However, depending on the substrate their hydrolysing activity of long polypeptide substrates was significantly higher or unchanged. Furthermore, our data revealed an altered MHC class I antigen-processing efficiency of 20S proteasomes from liver of aged rats. We therefore suggest that the age-related intramolecular alteration of hepatic proteasomes modifies its cleavage preferences without a general decrease of its activity. Such modifications could have implications on protein homeostasis as well as on MHC class I antigen presentation as part of the immunosenescence process.
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Affiliation(s)
- Sabrina Gohlke
- />Institute of Biochemistry, Charité-Universitätsmedizin Berlin, CCM, CharitéCrossOver, Charitéplatz 1, 10117 Berlin, Germany
| | - Michele Mishto
- />Institute of Biochemistry, Charité-Universitätsmedizin Berlin, CCM, CharitéCrossOver, Charitéplatz 1, 10117 Berlin, Germany
- />Centro Interdipartimentale di Ricerca sul Cancro “Giorgio Prodi”, University of Bologna, Bologna, Italy
| | - Kathrin Textoris-Taube
- />Institute of Biochemistry, Charité-Universitätsmedizin Berlin, CCM, CharitéCrossOver, Charitéplatz 1, 10117 Berlin, Germany
| | - Christin Keller
- />Institute of Biochemistry, Charité-Universitätsmedizin Berlin, CCM, CharitéCrossOver, Charitéplatz 1, 10117 Berlin, Germany
| | - Carolin Giannini
- />Institute of Biochemistry, Charité-Universitätsmedizin Berlin, CCM, CharitéCrossOver, Charitéplatz 1, 10117 Berlin, Germany
| | - Francesco Vasuri
- />“F. Addarii” Institute of Oncology and Transplant Pathology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Elisa Capizzi
- />“F. Addarii” Institute of Oncology and Transplant Pathology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Antonia D’Errico-Grigioni
- />“F. Addarii” Institute of Oncology and Transplant Pathology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Peter-Michael Kloetzel
- />Institute of Biochemistry, Charité-Universitätsmedizin Berlin, CCM, CharitéCrossOver, Charitéplatz 1, 10117 Berlin, Germany
| | - Burkhardt Dahlmann
- />Institute of Biochemistry, Charité-Universitätsmedizin Berlin, CCM, CharitéCrossOver, Charitéplatz 1, 10117 Berlin, Germany
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Wang CH, Wu SB, Wu YT, Wei YH. Oxidative stress response elicited by mitochondrial dysfunction: implication in the pathophysiology of aging. Exp Biol Med (Maywood) 2013; 238:450-60. [PMID: 23856898 DOI: 10.1177/1535370213493069] [Citation(s) in RCA: 225] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Under normal physiological conditions, reactive oxygen species (ROS) serve as 'redox messengers' in the regulation of intracellular signalling, whereas excess ROS may induce irreversible damage to cellular components and lead to cell death by promoting the intrinsic apoptotic pathway through mitochondria. In the aging process, accumulation of mitochondria DNA mutations, impairment of oxidative phosphorylation as well as an imbalance in the expression of antioxidant enzymes result in further overproduction of ROS. This mitochondrial dysfunction-elicited ROS production axis forms a vicious cycle, which is the basis of mitochondrial free radical theory of aging. In addition, several lines of evidence have emerged recently to demonstrate that ROS play crucial roles in the regulation of cellular metabolism, antioxidant defence and posttranslational modification of proteins. We first discuss the oxidative stress responses, including metabolites redistribution and alteration of the acetylation status of proteins, in human cells with mitochondrial dysfunction and in aging. On the other hand, autophagy and mitophagy eliminate defective mitochondria and serve as a scavenger and apoptosis defender of cells in response to oxidative stress during aging. These scenarios mediate the restoration or adaptation of cells to respond to aging and age-related disorders for survival. In the natural course of aging, the homeostasis in the network of oxidative stress responses is disturbed by a progressive increase in the intracellular level of the ROS generated by defective mitochondria. Caloric restriction, which is generally thought to promote longevity, has been reported to enhance the efficiency of this network and provide multiple benefits to tissue cells. In this review, we emphasize the positive and integrative roles of mild oxidative stress elicited by mitochondria in the regulation of adaptation, anti-aging and scavenging pathway beyond their roles in the vicious cycle of mitochondrial dysfunction in the aging process.
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Affiliation(s)
- Chih-Hao Wang
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
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42
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Abstract
Constitutive autophagy is important for the control of the quality of proteins and organelles to maintain cell function. Damaged proteins and organelles accumulate in aged organs. The level of autophagic activity decreases with aging. Autophagic activity is regulated by many factors, such as the insulin receptor-signaling pathway, the TOR pathway, Sirt1, and caloric restriction. Autophagy-related genes are known to be essential for the lifespan extension of flies, nematodes, and mice. The inhibition of autophagy decreases the lifespan, and on the other hand, the induction of autophagy can prolong the lifespan. Pharmacological intervention to extend the lifespan has demonstrated a crucial role for autophagy. Heart failure is an age-related disease, as the incidence increases with age. The autophagic activity of the heart decreases during aging. Cardiac-specific autophagy-deficient mice have shown no obvious phenotype up to 10 weeks of age. However, these mice began to die after the age of 6 months, with a significant increase in the left ventricular dimensions and a decrease in the fractional shortening of the left ventricle compared with control mice. This indicates that continuous constitutive autophagy during aging has a crucial role in maintaining cardiac structure and function.
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Pallauf K, Rimbach G. Autophagy, polyphenols and healthy ageing. Ageing Res Rev 2013; 12:237-52. [PMID: 22504405 DOI: 10.1016/j.arr.2012.03.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/22/2012] [Accepted: 03/30/2012] [Indexed: 01/25/2023]
Abstract
Autophagy is a lysosomal degradation process that evolved as a starvation response in lower eukaryotes and has gained numerous functions in higher organisms. In animals, autophagy works as a central process in cellular quality control by removing waste or excess proteins and organelles. Impaired autophagy and the age-related decline of this pathway favour the pathogenesis of many diseases that occur especially at higher age such as neurodegenerative diseases and cancer. Caloric restriction (CR) promotes longevity and healthy ageing. Currently, the contributing role of autophagy in the context of CR-induced health benefits is being unravelled. Furthermore recent studies imply that the advantages from polyphenol consumption may be also connected to autophagy induction. In this review, the literature on autophagy regulation by (dietary) polyphenols such as resveratrol, catechin, quercetin, silibinin and curcumin is discussed with a focus on the underlying molecular mechanisms. Special attention is paid to the implications of age-related autophagy decline for diseases and the possibility of dietary countermeasures.
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Bildirici I, Longtine MS, Chen B, Nelson DM. Survival by self-destruction: a role for autophagy in the placenta? Placenta 2012; 33:591-8. [PMID: 22652048 PMCID: PMC3389146 DOI: 10.1016/j.placenta.2012.04.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 04/17/2012] [Accepted: 04/17/2012] [Indexed: 12/20/2022]
Abstract
Autophagy is a burgeoning area of research from yeast to humans. Although previously described as a death pathway, autophagy is now considered an important survival phenomenon in response to environmental stressors to which most organs are exposed. Despite an ever expanding literature in non-placental cells, studies of autophagy in the placenta are lagging. We review the regulation of autophagy, summarize available placental studies of autophagy, and highlight potential areas for future research. We believe that such studies will yield novel insights into how placentas protect the survival of the species by "self-eating".
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Affiliation(s)
- I Bildirici
- Department of Obstetrics and Gynecology, Acibadem University School of Medicine, Istanbul, Turkey.
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Yamaguchi O, Taneike M, Otsu K. Cooperation between proteolytic systems in cardiomyocyte recycling. Cardiovasc Res 2012; 96:46-52. [DOI: 10.1093/cvr/cvs236] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sakuma K, Yamaguchi A. Sarcopenia and cachexia: the adaptations of negative regulators of skeletal muscle mass. J Cachexia Sarcopenia Muscle 2012; 3:77-94. [PMID: 22476916 PMCID: PMC3374017 DOI: 10.1007/s13539-011-0052-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 11/08/2011] [Indexed: 12/25/2022] Open
Abstract
Recent advances in our understanding of the biology of muscle, and how anabolic and catabolic stimuli interact to control muscle mass and function, have led to new interest in the pharmacological treatment of muscle wasting. Loss of muscle occurs as a consequence of several chronic diseases (cachexia) as well as normal aging (sarcopenia). Although many negative regulators [Atrogin-1, muscle ring finger-1, nuclear factor-kappaB (NF-κB), myostatin, etc.] have been proposed to enhance protein degradation during both sarcopenia and cachexia, the adaptation of mediators markedly differs among these conditions. Sarcopenic and cachectic muscles have been demonstrated to be abundant in myostatin- and apoptosis-linked molecules. The ubiquitin-proteasome system (UPS) is activated during many different types of cachexia (cancer cachexia, cardiac heart failure, chronic obstructive pulmonary disease), but not many mediators of the UPS change during sarcopenia. NF-κB signaling is activated in cachectic, but not in sarcopenic, muscle. Some studies have indicated a change of autophagic signaling during both sarcopenia and cachexia, but the adaptation remains to be elucidated. This review provides an overview of the adaptive changes in negative regulators of muscle mass in both sarcopenia and cachexia.
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Affiliation(s)
- Kunihiro Sakuma
- Research Center for Physical Fitness, Sports and Health, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku-cho, Toyohashi, 441-8580, Japan,
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Tranah GJ, Lam ET, Katzman SM, Nalls MA, Zhao Y, Evans DS, Yokoyama JS, Pawlikowska L, Kwok PY, Mooney S, Kritchevsky S, Goodpaster BH, Newman AB, Harris TB, Manini TM, Cummings SR. Mitochondrial DNA sequence variation is associated with free-living activity energy expenditure in the elderly. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1691-700. [PMID: 22659402 DOI: 10.1016/j.bbabio.2012.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 05/19/2012] [Accepted: 05/24/2012] [Indexed: 01/11/2023]
Abstract
The decline in activity energy expenditure underlies a range of age-associated pathological conditions, neuromuscular and neurological impairments, disability, and mortality. The majority (90%) of the energy needs of the human body are met by mitochondrial oxidative phosphorylation (OXPHOS). OXPHOS is dependent on the coordinated expression and interaction of genes encoded in the nuclear and mitochondrial genomes. We examined the role of mitochondrial genomic variation in free-living activity energy expenditure (AEE) and physical activity levels (PAL) by sequencing the entire (~16.5 kilobases) mtDNA from 138 Health, Aging, and Body Composition Study participants. Among the common mtDNA variants, the hypervariable region 2 m.185G>A variant was significantly associated with AEE (p=0.001) and PAL (p=0.0005) after adjustment for multiple comparisons. Several unique nonsynonymous variants were identified in the extremes of AEE with some occurring at highly conserved sites predicted to affect protein structure and function. Of interest is the p.T194M, CytB substitution in the lower extreme of AEE occurring at a residue in the Qi site of complex III. Among participants with low activity levels, the burden of singleton variants was 30% higher across the entire mtDNA and OXPHOS complex I when compared to those having moderate to high activity levels. A significant pooled variant association across the hypervariable 2 region was observed for AEE and PAL. These results suggest that mtDNA variation is associated with free-living AEE in older persons and may generate new hypotheses by which specific mtDNA complexes, genes, and variants may contribute to the maintenance of activity levels in late life.
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Affiliation(s)
- Gregory J Tranah
- California Pacific Medical Center Research Institute, San Francisco, San Francisco, CA 94107, USA.
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Rezzani R, Stacchiotti A, Rodella LF. Morphological and biochemical studies on aging and autophagy. Ageing Res Rev 2012; 11:10-31. [PMID: 21939784 DOI: 10.1016/j.arr.2011.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/05/2011] [Accepted: 09/08/2011] [Indexed: 12/11/2022]
Abstract
To maintain health in the elderly is a crucial objective for modern medicine that involves both basic and clinical researches. Autophagy is a fundamental auto-cannibalizing process that preserves cellular homeostasis and, if altered, either by excess or defect, greatly changes cell fate and can result in incapacitating human diseases. Efficient autophagy may prolong lifespan, but unfortunately this process becomes less efficient with age. The present review is focused on the close relationship between autophagy and age-related disorders in different tissues/organs and in transgenic animal models. In particular, it comments on the up to date literature on mechanisms responsible for age-related impairment of autophagy. Moreover, before discussing about these mechanisms, it is necessary to describe the metabolic autophagic regulation of autophagy and the proteins involved in this process. At the end, these data would summarize the autophagic link with aging process, as important tools in the future biogerontology scenario.
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Tranah GJ, Nalls MA, Katzman SM, Yokoyama JS, Lam ET, Zhao Y, Mooney S, Thomas F, Newman AB, Liu Y, Cummings SR, Harris TB, Yaffe K. Mitochondrial DNA sequence variation associated with dementia and cognitive function in the elderly. J Alzheimers Dis 2012; 32:357-72. [PMID: 22785396 PMCID: PMC4156011 DOI: 10.3233/jad-2012-120466] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mitochondrial dysfunction is a prominent hallmark of Alzheimer's disease (AD). Mitochondrial DNA (mtDNA) damage may be a major cause of abnormal reactive oxidative species production in AD or increased neuronal susceptibility to oxidative injury during aging. The purpose of this study was to assess the influence of mtDNA sequence variation on clinically significant cognitive impairment and dementia risk in the population-based Health, Aging, and Body Composition (Health ABC) Study. We first investigated the role of common mtDNA haplogroups and individual variants on dementia risk and 8-year change on the Modified Mini-Mental State Examination (3MS) and Digit Symbol Substitution Test (DSST) among 1,631 participants of European genetic ancestry. Participants were free of dementia at baseline and incidence was determined in 273 cases from hospital and medication records over 10-12 follow-up years. Participants from haplogroup T had a statistically significant increased risk of developing dementia (OR = 1.86, 95% CI = 1.23, 2.82, p = 0.0008) and haplogroup J participants experienced a statistically significant 8-year decline in 3MS (β = -0.14, 95% CI = -0.27, -0.03, p = 0.0006), both compared with common haplogroup H. The m.15244A>G, p.G166G, CytB variant was associated with a significant decline in DSST score (β = -0.58, 95% CI -0.89, -0.28, p = 0.00019) and the m.14178T>C, p.I166V, ND6 variant was associated with a significant decline in 3MS score (β = -0.87, 95% CI -1.31, -3.86, p = 0.00012). Finally, we sequenced the complete ~16.5 kb mtDNA from 135 Health ABC participants and identified several highly conserved and potentially functional nonsynonymous variants unique to 22 dementia cases and aggregate sequence variation across the hypervariable 2-3 regions that influences 3MS and DSST scores.
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Affiliation(s)
- Gregory J Tranah
- California Pacific Medical Center Research Institute, San Francisco, CA, USA.
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Wang JH, Ahn IS, Fischer TD, Byeon JI, Dunn WA, Behrns KE, Leeuwenburgh C, Kim JS. Autophagy suppresses age-dependent ischemia and reperfusion injury in livers of mice. Gastroenterology 2011; 141:2188-2199.e6. [PMID: 21854730 PMCID: PMC3221865 DOI: 10.1053/j.gastro.2011.08.005] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 07/31/2011] [Accepted: 08/08/2011] [Indexed: 01/05/2023]
Abstract
BACKGROUND & AIMS As life expectancy increases, there are greater numbers of patients with liver diseases who require surgery or transplantation. Livers of older patients have significantly less reparative capacity following ischemia and reperfusion (I/R) injury, which occurs during these operations. There are no strategies to reduce the age-dependent I/R injury. We investigated the role of autophagy in the age dependence of sensitivity to I/R injury. METHODS Hepatocytes and livers from 3- and 26-month-old mice were subjected to in vitro and in vivo I/R, respectively. We analyzed changes in autophagy-related proteins (Atg). Mitochondrial dysfunction was visualized using confocal and intravital multi-photon microscopy of isolated hepatocytes and livers from anesthetized mice, respectively. RESULTS Immunoblot, autophagic flux, genetic, and imaging analyses all associated the increase in sensitivity to I/R injury with age with decreased autophagy and subsequent mitochondrial dysfunction due to calpain-mediated loss of Atg4B. Overexpression of either Atg4B or Beclin-1 recovered Atg4B, increased autophagy, blocked the onset of the mitochondrial permeability transition, and suppressed cell death after I/R in old hepatocytes. Coimmunoprecipitation analysis of hepatocytes and Atg3-knockout cells showed an interaction between Beclin-1 and Atg3, a protein required for autophagosome formation. Intravital multi-photon imaging revealed that overexpression of Beclin-1 or Atg4B attenuated autophagic defects and mitochondrial dysfunction in livers of older mice after I/R. CONCLUSIONS Loss of Atg4B in livers of old mice increases their sensitivity to I/R injury. Increasing autophagy might ameliorate liver damage and restore mitochondrial function after I/R.
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Affiliation(s)
- Jin-Hee Wang
- Department of Surgery, Division of Biology of Aging, University of Florida, Gainesville, Florida, USA
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