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Da W, Chen Q, Shen B. The current insights of mitochondrial hormesis in the occurrence and treatment of bone and cartilage degeneration. Biol Res 2024; 57:37. [PMID: 38824571 PMCID: PMC11143644 DOI: 10.1186/s40659-024-00494-1] [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: 07/31/2023] [Accepted: 04/03/2024] [Indexed: 06/03/2024] Open
Abstract
It is widely acknowledged that aging, mitochondrial dysfunction, and cellular phenotypic abnormalities are intricately associated with the degeneration of bone and cartilage. Consequently, gaining a comprehensive understanding of the regulatory patterns governing mitochondrial function and its underlying mechanisms holds promise for mitigating the progression of osteoarthritis, intervertebral disc degeneration, and osteoporosis. Mitochondrial hormesis, referred to as mitohormesis, represents a cellular adaptive stress response mechanism wherein mitochondria restore homeostasis and augment resistance capabilities against stimuli by generating reactive oxygen species (ROS), orchestrating unfolded protein reactions (UPRmt), inducing mitochondrial-derived peptides (MDP), instigating mitochondrial dynamic changes, and activating mitophagy, all prompted by low doses of stressors. The varying nature, intensity, and duration of stimulus sources elicit divergent degrees of mitochondrial stress responses, subsequently activating one or more signaling pathways to initiate mitohormesis. This review focuses specifically on the effector molecules and regulatory networks associated with mitohormesis, while also scrutinizing extant mechanisms of mitochondrial dysfunction contributing to bone and cartilage degeneration through oxidative stress damage. Additionally, it underscores the potential of mechanical stimulation, intermittent dietary restrictions, hypoxic preconditioning, and low-dose toxic compounds to trigger mitohormesis, thereby alleviating bone and cartilage degeneration.
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Affiliation(s)
- Wacili Da
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Quan Chen
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Bin Shen
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
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Gettings SM, Timbury W, Dmochowska A, Sharma R, McGonigle R, MacKenzie LE, Miquelard-Garnier G, Bourbia N. Polyethylene terephthalate (PET) micro- and nanoplastic particles affect the mitochondrial efficiency of human brain vascular pericytes without inducing oxidative stress. NANOIMPACT 2024; 34:100508. [PMID: 38663501 DOI: 10.1016/j.impact.2024.100508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 04/28/2024]
Abstract
The objective of this investigation was to evaluate the influence of micro- and nanoplastic particles composed of polyethylene terephthalate (PET), a significant contributor to plastic pollution, on human brain vascular pericytes. Specifically, we delved into their impact on mitochondrial functionality, oxidative stress, and the expression of genes associated with oxidative stress, ferroptosis and mitochondrial functions. Our findings demonstrate that the exposure of a monoculture of human brain vascular pericytes to PET particles in vitro at a concentration of 50 μg/ml for a duration of 3, 6 and 10 days did not elicit oxidative stress. Notably, we observed a reduction in various aspects of mitochondrial respiration, including maximal respiration, spare respiratory capacity, and ATP production in pericytes subjected to PET particles for 3 days, with a mitochondrial function recovery at 6 and 10 days. Furthermore, there were no statistically significant alterations in mitochondrial DNA copy number, or in the expression of genes linked to oxidative stress and ferroptosis, but an increase of the expression of the gene mitochondrial transcription factor A (TFAM) was noted at 3 days exposure. These outcomes suggest that, at a concentration of 50 μg/ml, PET particles do not induce oxidative stress in human brain vascular pericytes. Instead, at 3 days exposure, PET exposure impairs mitochondrial functions, but this is recovered at 6-day exposure. This seems to indicate a potential mitochondrial hormesis response (mitohormesis) is incited, involving the gene TFAM. Further investigations are warranted to explore the stages of mitohormesis and the potential consequences of plastics on the integrity of the blood-brain barrier and intercellular interactions. This research contributes to our comprehension of the potential repercussions of nanoplastic pollution on human health and underscores the imperative need for ongoing examinations into the exposure to plastic particles.
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Affiliation(s)
- Sean M Gettings
- UK Health Security Agency, Radiation Effects Department, Radiation Protection Science Division, Harwell Science Campus, Didcot, Oxfordshire OX11 0RQ, UK
| | - William Timbury
- UK Health Security Agency, Radiation Effects Department, Radiation Protection Science Division, Harwell Science Campus, Didcot, Oxfordshire OX11 0RQ, UK
| | - Anna Dmochowska
- Laboratoire PIMM, CNRS, Arts et Métiers Institute of Technology, Cnam, HESAM Universite, 75013 Paris, France
| | - Riddhi Sharma
- UK Health Security Agency, Radiation Effects Department, Radiation Protection Science Division, Harwell Science Campus, Didcot, Oxfordshire OX11 0RQ, UK
| | - Rebecca McGonigle
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1RD, UK
| | - Lewis E MacKenzie
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1RD, UK
| | - Guillaume Miquelard-Garnier
- Laboratoire PIMM, CNRS, Arts et Métiers Institute of Technology, Cnam, HESAM Universite, 75013 Paris, France
| | - Nora Bourbia
- UK Health Security Agency, Radiation Effects Department, Radiation Protection Science Division, Harwell Science Campus, Didcot, Oxfordshire OX11 0RQ, UK.
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Casanova A, Wevers A, Navarro-Ledesma S, Pruimboom L. Mitochondria: It is all about energy. Front Physiol 2023; 14:1114231. [PMID: 37179826 PMCID: PMC10167337 DOI: 10.3389/fphys.2023.1114231] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 03/29/2023] [Indexed: 05/15/2023] Open
Abstract
Mitochondria play a key role in both health and disease. Their function is not limited to energy production but serves multiple mechanisms varying from iron and calcium homeostasis to the production of hormones and neurotransmitters, such as melatonin. They enable and influence communication at all physical levels through interaction with other organelles, the nucleus, and the outside environment. The literature suggests crosstalk mechanisms between mitochondria and circadian clocks, the gut microbiota, and the immune system. They might even be the hub supporting and integrating activity across all these domains. Hence, they might be the (missing) link in both health and disease. Mitochondrial dysfunction is related to metabolic syndrome, neuronal diseases, cancer, cardiovascular and infectious diseases, and inflammatory disorders. In this regard, diseases such as cancer, Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), chronic fatigue syndrome (CFS), and chronic pain are discussed. This review focuses on understanding the mitochondrial mechanisms of action that allow for the maintenance of mitochondrial health and the pathways toward dysregulated mechanisms. Although mitochondria have allowed us to adapt to changes over the course of evolution, in turn, evolution has shaped mitochondria. Each evolution-based intervention influences mitochondria in its own way. The use of physiological stress triggers tolerance to the stressor, achieving adaptability and resistance. This review describes strategies that could recover mitochondrial functioning in multiple diseases, providing a comprehensive, root-cause-focused, integrative approach to recovering health and treating people suffering from chronic diseases.
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Affiliation(s)
- Amaloha Casanova
- Department of Physiotherapy, University of Granada, Granada, Spain
- Faculty of Health Sciences, Melilla, Spain
- PNI Europe, The Hague, Netherlands
- Chair of Clinical Psychoneuroimmunology, University of Granada and PNI Europe, Granada, Spain
| | - Anne Wevers
- Department of Physiotherapy, University of Granada, Granada, Spain
- Faculty of Health Sciences, Melilla, Spain
- PNI Europe, The Hague, Netherlands
- Chair of Clinical Psychoneuroimmunology, University of Granada and PNI Europe, Granada, Spain
| | - Santiago Navarro-Ledesma
- Department of Physiotherapy, University of Granada, Granada, Spain
- Faculty of Health Sciences, Melilla, Spain
- PNI Europe, The Hague, Netherlands
- Chair of Clinical Psychoneuroimmunology, University of Granada and PNI Europe, Granada, Spain
| | - Leo Pruimboom
- PNI Europe, The Hague, Netherlands
- Chair of Clinical Psychoneuroimmunology, University of Granada and PNI Europe, Granada, Spain
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Lee DH, Lee IK. Can lipophilic pollutants in adipose tissue explain weight change-related risk in type 2 diabetes mellitus? J Diabetes Investig 2023; 14:528-530. [PMID: 36722694 PMCID: PMC10034949 DOI: 10.1111/jdi.13976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 02/02/2023] Open
Affiliation(s)
- Duk-Hee Lee
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - In-Kyu Lee
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Daegu, Korea
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Pagano G, Brouziotis AA, Lyons D, Čarapar I, Oral R, Tez S, Thomas PJ, Tommasi F, Libralato G, Guida M, Trifuoggi M. Hormetic Effects of Cerium, Lanthanum and Their Combination at Sub-micromolar Concentrations in Sea Urchin Sperm. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2023; 110:65. [PMID: 36922429 PMCID: PMC10017572 DOI: 10.1007/s00128-023-03701-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Rare earth elements (REEs) cerium (Ce) and lanthanum (La) and their combination were tested across a concentration range, from toxic (10-4 to 10-5 M) to lower concentrations (10-6 to 10-8 M) for their effects on sea urchin (Sphaerechinus granularis) sperm. A significantly decreased fertilization rate (FR) was found for sperm exposed to 10-5 M Ce, La and their combination, opposed to a significant increase of FR following 10-7 and 10-8 M REE sperm exposure. The offspring of REE-exposed sperm showed significantly increased developmental defects following sperm exposure to 10-5 M REEs vs. untreated controls, while exposure to 10-7 and 10-8 M REEs resulted in significantly decreased rates of developmental defects. Both of observed effects-on sperm fertilization success and on offspring quality-were closely exerted by Ce or La or their combination.
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Affiliation(s)
- Giovanni Pagano
- Department of Chemical Sciences, Federico II Naples University, I-80126, Naples, Italy.
| | - Antonios Apostolos Brouziotis
- Department of Chemical Sciences, Federico II Naples University, I-80126, Naples, Italy
- Department of Biology, Federico II Naples University, I-80126, Naples, Italy
| | - Daniel Lyons
- Center for Marine Research, Ruđer Bošković Institute, HR-52210, Rovinj, Croatia
| | - Ivana Čarapar
- Center for Marine Research, Ruđer Bošković Institute, HR-52210, Rovinj, Croatia
| | - Rahime Oral
- Faculty of Fisheries, Ege University, Bornova, TR-35100, İzmir, Turkey
| | - Serkan Tez
- Faculty of Fisheries, Ege University, Bornova, TR-35100, İzmir, Turkey
| | - Philippe J Thomas
- Environment and Climate Change Canada, Science & Technology Branch, National Wildlife Research Center, Carleton University, K1A 0H3, Ottawa, ON, Canada
| | - Franca Tommasi
- Department of Biology, "Aldo Moro" Bari University, I-70125, Bari, Italy
| | - Giovanni Libralato
- Department of Biology, Federico II Naples University, I-80126, Naples, Italy
| | - Marco Guida
- Department of Biology, Federico II Naples University, I-80126, Naples, Italy
| | - Marco Trifuoggi
- Department of Chemical Sciences, Federico II Naples University, I-80126, Naples, Italy
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Kim SA, Lee H, Park SM, Kim MJ, Lee YM, Yoon YR, Lee HK, Moon HB, Lee IK, Lee DH. Effect of Low-Dose Persistent Organic Pollutants on Mitochondrial Function: Human and in Vitro Evidence. Diabetes Metab J 2022; 46:592-604. [PMID: 35081303 PMCID: PMC9353568 DOI: 10.4093/dmj.2021.0132] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/20/2021] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Chronic exposure to low-dose persistent organic pollutants (POPs) can induce mitochondrial dysfunction. This study evaluated the association between serum POP concentrations and oxygen consumption rate (OCR) as a marker of mitochondrial function in humans and in vitro cells. METHODS Serum concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in 323 adults. The OCRs of platelets and peripheral blood mononuclear cells (PBMCs) were assessed in 20 mL of fresh blood using a Seahorse XF analyzer. Additionally, the in vitro effects of Arochlor-1254, β-hexachlorocyclohexane, and p,p´-dichlorodiphenyltrichloroethane at concentrations of 0.1 pM to 100 nM were evaluated in human platelets, human PBMCs, and Jurkat T-cells. RESULTS The association between serum POP concentrations and OCR differed depending on the cell type. As serum OCP concentrations increased, basal platelet OCR levels decreased significantly; according to the OCP quintiles of summary measure, they were 8.6, 9.6, 8.2, 8.0, and 7.1 pmol/min/μg (P trend=0.005). Notably, the basal PBMC OCR levels decreased remarkably as the serum PCB concentration increased. PBMC OCR levels were 46.5, 34.3, 29.1, 16.5, and 13.1 pmol/min/μg according to the PCB quintiles of summary measure (P trend <0.001), and this inverse association was consistently observed in all subgroups stratified by age, sex, obesity, type 2 diabetes mellitus, and hypertension, respectively. In vitro experimental studies have also demonstrated that chronic exposure to low-dose POPs could decrease OCR levels. CONCLUSION The findings from human and in vitro studies suggest that chronic exposure to low-dose POPs can induce mitochondrial dysfunction by impairing oxidative phosphorylation.
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Affiliation(s)
- Se-A Kim
- Department of Biomedical Science, Graduate School, Kyungpook National University, Daegu, Korea
| | - Hoyul Lee
- Bio-Medical Research Institute, Kyungpook National University Hospital, Daegu, Korea
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Daegu, Korea
| | - Sung-Mi Park
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Daegu, Korea
| | - Mi-Jin Kim
- Research Institute of Aging and Metabolism, Kyungpook National University, Daegu,
Korea
| | - Yu-Mi Lee
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Young-Ran Yoon
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, Kyungpook National University, Daegu, Korea
- Department of Biomedical Science, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Hyun-Kyung Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan, Korea
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan, Korea
| | - In-Kyu Lee
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Daegu, Korea
- Research Institute of Aging and Metabolism, Kyungpook National University, Daegu,
Korea
- Department of Internal Medicine, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Duk-Hee Lee
- Department of Biomedical Science, Graduate School, Kyungpook National University, Daegu, Korea
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
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Type 2 Diabetes Induced by Changes in Proteomic Profiling of Zebrafish Chronically Exposed to a Mixture of Organochlorine Pesticides at Low Concentrations. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19094991. [PMID: 35564385 PMCID: PMC9100612 DOI: 10.3390/ijerph19094991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/07/2022] [Accepted: 04/15/2022] [Indexed: 02/04/2023]
Abstract
Effect of organochlorine pesticides (OCPs) mixtures on development of type 2 diabetes mellitus (T2DM) and the underlying mechanism, especially at protein levels, are largely unknown. We exposed a mixture of five OCPs to zebrafish at concentrations of 0, 0.05, 0.25, 2.5, and 25 μg/L for 12 weeks. Differentially expressed proteins (DEPs) were quantitatively identified in female zebrafish livers, and its functional study was conducted. The significantly high glucose and low insulin levels were observed only at 0.05 μg/L, linking to the different pattern of DEPs than other concentrations. A total of 1082 proteins was quantified, of which 321 proteins formed 6 clusters in protein dynamics analysis. The enriched pathways in cluster 3 showing distinct pattern of DEPs could explain the nonlinear response at 0.05 μg/L, indicating that OCP mixtures adversely affected proteins associated with mitochondrial function and energy metabolism. We proposed a feasible mechanism that decrease in expression of aldehyde dehydrogenase led to abnormal accumulation of aldehydes, reducing expression of glyceraldehyde 3-phosphate dehydrogenase, and resulting in disruption of glucose homeostasis. Our findings help to better understand the causality of T2DM by exposure to OCP mixtures and to identify biomarkers in the protein expression level.
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Lee DH. Can Environmental Pollutants Be a Factor Linking Obesity and COVID-19? J Korean Med Sci 2021; 36:e305. [PMID: 34751012 PMCID: PMC8575764 DOI: 10.3346/jkms.2021.36.e305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/12/2021] [Indexed: 11/20/2022] Open
Affiliation(s)
- Duk-Hee Lee
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Korea.
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Agathokleous E, Calabrese EJ. Environmental toxicology and ecotoxicology: How clean is clean? Rethinking dose-response analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 746:138769. [PMID: 32389333 DOI: 10.1016/j.scitotenv.2020.138769] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 05/17/2023]
Abstract
Global agendas for sustaining clean environments target remediation of multimedia contaminants, but how clean is clean? Environmental Toxicology and Ecotoxicology focus on issues concerning "clean". However, the models used to assess the effects of environmental multimedia on individual living organisms and communities or populations in Environmental Toxicology and Ecotoxicology may fail to provide reliable estimates for risk assessment and optimize health. Recent developments in low-dose effects research provide a novel means in Environmental Toxicology and Ecotoxicology to improve the quality of hazard and risk assessment.
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Affiliation(s)
- Evgenios Agathokleous
- Institute of Ecology, School of Applied Meteorology, Nanjing University of Information Science and Technology (NUIST), Ningliu Rd. 219, Nanjing, Jiangsu 210044, China.
| | - Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003, USA
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Lee D, Jacobs DR, Lind L, Lind PM. Lipophilic Environmental Chemical Mixtures Released During Weight‐Loss: The Need to Consider Dynamics. Bioessays 2020; 42:e1900237. [DOI: 10.1002/bies.201900237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/06/2020] [Indexed: 12/25/2022]
Affiliation(s)
- Duk‐Hee Lee
- Department of Preventive MedicineSchool of MedicineKyungpook National University Daegu 41944 Korea
| | - David R Jacobs
- Division of Epidemiology and Community HealthSchool of Public HealthUniversity of Minnesota Minneapolis Minnesota 55454 USA
| | - Lars Lind
- Department of Medical SciencesCardiovascular EpidemiologyUppsala University Uppsala 75237 Sweden
| | - P. Monica Lind
- Department of Medical SciencesOccupational and Environmental MedicineUppsala University Uppsala 75185 Sweden
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Lee YM, Park SH, Lee DH. Intensive weight loss and cognition: The dynamics of persistent organic pollutants in adipose tissue can explain the unexpected results from the Action for Health in Diabetes (Look AHEAD) study. Alzheimers Dement 2020; 16:696-703. [PMID: 32096335 DOI: 10.1002/alz.12065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/03/2019] [Accepted: 12/05/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The aim of this paper is to propose a new hypothesis for the role of lipophilic chemical mixtures stored in adipose tissue in the development of dementia. Specifically, we present how the dynamics of these chemicals can explain the unexpected findings from the Action for Health in Diabetes (Look AHEAD) study, which failed to show long-term benefits of intentional weight loss on cognition, despite substantial improvements in many known risk factors for dementia. Moreover, we discuss how the role of obesity in the risk of dementia can change depending on the dynamics of these chemicals in adipose tissue. NEW HYPOTHESIS Human adipose tissue is widely contaminated with various neurotoxic chemicals. Typical examples are persistent organic pollutants (POPs), strong lipophilic chemicals with long half-lives. Both unintentional and intentional weight loss increases the release of POPs from adipocytes into the circulation. As POPs in the blood can easily reach the brain, the intentional weight-loss group of the Look AHEAD study may have experienced an unappreciated and long-term disadvantage on their cognition. Additionally, POPs may be involved in the link between obesity and dementia, as dysfunctional hypertrophic adipocytes enhance the release of POPs from adipocytes to the circulation through uncontrolled lipolysis. In contrast, metabolically healthy obese people may have a low risk of dementia because the safe storage of POPs in adipose tissue would decrease the amount of POPs reaching the brain. MAJOR CHALLENGES FOR THE HYPOTHESIS In human studies, there are practical difficulties involved with measuring POPs in the blood, including high costs and complex assays. As the serum concentrations of POPs are continuously affected by weight loss and gain, prospective studies may require serial measurements of POPs. In in-vitro and in-vivo experimental studies, how to simulate the exposure dose, duration, and mixture patterns in humans would be critical. LINKAGE TO OTHER MAJOR THEORIES Even though POPs are direct neurotoxins at a high dosage, low-dose POPs are mitochondrial toxins. Therefore, chronic exposure to low-dose POPs is linked to known key interrelated mechanisms in the pathogenesis of dementia, such as mitochondrial dysfunction and neuroinflammation.
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Affiliation(s)
- Yu-Mi Lee
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Sun-Hee Park
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Republic of Korea
| | - Duk-Hee Lee
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
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