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Asthana P, Wong HLX. Preventing obesity, insulin resistance and type 2 diabetes by targeting MT1-MMP. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167081. [PMID: 38367902 DOI: 10.1016/j.bbadis.2024.167081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/19/2024]
Abstract
Obesity is one of the predominant risk factors for type 2 diabetes. Despite all the modern advances in medicine, an effective drug treatment for obesity without overt side effects has not yet been found. The discovery of growth and differentiation factor 15 (GDF15), an appetite-regulating hormone, created hopes for the treatment of obesity. However, an insufficient understanding of the physiological regulation of GDF15 has been a major obstacle to mitigating GDF15-centric treatment of obesity. Our recent studies revealed how a series of proteolytic events predominantly mediated by membrane-type 1 matrix metalloproteinase (MT1-MMP/MMP14), a key cell-surface metalloproteinase involved in extracellular remodeling, contribute to the pathogenesis of metabolic disorders, including obesity and diabetes. The MT1-MMP-mediated cleavage of the GDNF family receptor-α-like (GFRAL), a key neuronal receptor of GDF15, controls the satiety center in the hindbrain, thereby regulating non-homeostatic appetite and bodyweight changes. Furthermore, increased activation of MT1-MMP does not only lead to increased risk of obesity, but also causes age-associated insulin resistance by cleaving Insulin Receptor in major metabolic tissues. Importantly, inhibition of MT1-MMP effectively protects against obesity and diabetes, revealing the therapeutic potential of targeting MT1-MMP for the management of metabolic disorders.
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Affiliation(s)
- Pallavi Asthana
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong
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2
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Rhea EM, Banks WA, Raber J. Insulin Resistance in Peripheral Tissues and the Brain: A Tale of Two Sites. Biomedicines 2022; 10:1582. [PMID: 35884888 PMCID: PMC9312939 DOI: 10.3390/biomedicines10071582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 12/12/2022] Open
Abstract
The concept of insulin resistance has been around since a few decades after the discovery of insulin itself. To allude to the classic Charles Dicken's novel published 62 years before the discovery of insulin, in some ways, this is the best of times, as the concept of insulin resistance has expanded to include the brain, with the realization that insulin has a life beyond the regulation of glucose. In other ways, it is the worst of times as insulin resistance is implicated in devastating diseases, including diabetes mellitus, obesity, and Alzheimer's disease (AD) that affect the brain. Peripheral insulin resistance affects nearly a quarter of the United States population in adults over age 20. More recently, it has been implicated in AD, with the degree of brain insulin resistance correlating with cognitive decline. This has led to the investigation of brain or central nervous system (CNS) insulin resistance and the question of the relation between CNS and peripheral insulin resistance. While both may involve dysregulated insulin signaling, the two conditions are not identical and not always interlinked. In this review, we compare and contrast the similarities and differences between peripheral and CNS insulin resistance. We also discuss how an apolipoprotein involved in insulin signaling and related to AD, apolipoprotein E (apoE), has distinct pools in the periphery and CNS and can indirectly affect each system. As these systems are both separated but also linked via the blood-brain barrier (BBB), we discuss the role of the BBB in mediating some of the connections between insulin resistance in the brain and in the peripheral tissues.
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Affiliation(s)
- Elizabeth M. Rhea
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA 98195, USA; (E.M.R.); (W.A.B.)
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - William A. Banks
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA 98195, USA; (E.M.R.); (W.A.B.)
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA
- Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR 97239, USA
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3
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Ou MY, Zhang H, Tan PC, Zhou SB, Li QF. Adipose tissue aging: mechanisms and therapeutic implications. Cell Death Dis 2022; 13:300. [PMID: 35379822 PMCID: PMC8980023 DOI: 10.1038/s41419-022-04752-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/03/2022] [Accepted: 03/18/2022] [Indexed: 01/10/2023]
Abstract
Adipose tissue, which is the crucial energy reservoir and endocrine organ for the maintenance of systemic glucose, lipid, and energy homeostasis, undergoes significant changes during aging. These changes cause physiological declines and age-related disease in the elderly population. Here, we review the age-related changes in adipose tissue at multiple levels and highlight the underlying mechanisms regulating the aging process. We also discuss the pathogenic pathways of age-related fat dysfunctions and their systemic negative consequences, such as dyslipidemia, chronic general inflammation, insulin resistance, and type 2 diabetes (T2D). Age-related changes in adipose tissue involve redistribution of deposits and composition, in parallel with the functional decline of adipocyte progenitors and accumulation of senescent cells. Multiple pathogenic pathways induce defective adipogenesis, inflammation, aberrant adipocytokine production, and insulin resistance, leading to adipose tissue dysfunction. Changes in gene expression and extracellular signaling molecules regulate the aging process of adipose tissue through various pathways. In addition, adipose tissue aging impacts other organs that are infiltrated by lipids, which leads to systemic inflammation, metabolic system disruption, and aging process acceleration. Moreover, studies have indicated that adipose aging is an early onset event in aging and a potential target to extend lifespan. Together, we suggest that adipose tissue plays a key role in the aging process and is a therapeutic target for the treatment of age-related disease, which deserves further study to advance relevant knowledge.
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Affiliation(s)
- Min-Yi Ou
- Department of Plastic & Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200011, Shanghai, China
| | - Hao Zhang
- Department of Plastic & Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200011, Shanghai, China
| | - Poh-Ching Tan
- Department of Plastic & Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200011, Shanghai, China
| | - Shuang-Bai Zhou
- Department of Plastic & Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200011, Shanghai, China.
| | - Qing-Feng Li
- Department of Plastic & Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200011, Shanghai, China.
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Iizuka Y, Kim H, Nakasatomi M, Matsumoto A, Shimizu J. Phenotypic and genotypic changes in obesity and type 2 diabetes of male KK mice with aging. Exp Anim 2021; 71:71-81. [PMID: 34588391 PMCID: PMC8828408 DOI: 10.1538/expanim.21-0109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Research into the prevention and treatment of age-related metabolic diseases are important in the present-day situation of the aging population. We propose that an elderly diabetic mouse model may be useful to such research as it exhibits deterioration of glucose and lipid metabolism. Although the KK mouse strain is commonly used as a model of moderate obesity and type 2 diabetes, the utility of this strain as an elderly obese and diabetic model mouse for research into aging remains unclear. The present study aimed to investigate age-related changes of glucose and lipid metabolism in male KK mice fed a standard chow diet. We demonstrate that 40 weeks KK mice exhibit age-related dysfunctions, such as development of insulin resistance associated with pancreatic islet hypertrophy and decreased lipolysis in white adipose tissue (WAT) compared with 15 weeks KK mice. However, aging does not appear to cause mitochondrial dysfunction of brown adipose tissue. Unexpectedly, hyperglycemia, potential glucose uptake in insulin-sensitive organs, hepatic lipid accumulation, hypertrophy of adipocytes, and inflammation in epididymal WAT did not worsen but rather compensated in 40 weeks KK mice. Our data indicate that the use of male KK mice as an elderly obese and diabetic mouse model has some limitations and in order to represent a useful elderly obese and diabetic animal model, it may be necessary to induce deterioration of glucose and lipid metabolism in KK mice through breeding with high-sucrose or high-fat diets.
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Affiliation(s)
- Yuzuru Iizuka
- Department of Microbiology and Immunology, Tokyo Women's Medical University School of Medicine
| | - Hyounju Kim
- Department of Health and Dietetics, Faculty of Health and Medical Science, Teikyo Heisei University
| | - Maki Nakasatomi
- Department of Clinical Dietetics & Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University
| | - Akiyo Matsumoto
- Department of Clinical Dietetics & Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University
| | - Jun Shimizu
- Department of Clinical Dietetics & Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University
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Moringa protein drink increases testosterone and anabolic status of men with hyperlipidemia: A randomized controlled study. TURKISH JOURNAL OF KINESIOLOGY 2021. [DOI: 10.31459/turkjkin.851832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Lu CH, Teng SW, Wu CZ, Hsieh CH, Chang JB, Chen YL, Liang YJ, Hsieh PS, Pei D, Lin JD. The roles of first phase, second phase insulin secretion, insulin resistance, and glucose effectiveness of having prediabetes in nonobese old Chinese women. Medicine (Baltimore) 2020; 99:e19562. [PMID: 32195965 PMCID: PMC7220224 DOI: 10.1097/md.0000000000019562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It has been established that prediabetes can causes significant comorbidities, particularly in the elderly. The deterioration of glucose metabolism are generally considered to be results of the impairment of the 4 factors: first, second insulin secretion (FPIS, SPIS, respectively), glucose effectiveness (GE), and insulin resistance. In this study, we enrolled older women to investigate their relationships with prediabetes.Five thousand four hundred eighty-two nonobese, nondiabetic women were included. They were divided into normal glucose tolerance and prediabetes groups. Receiver operating characteristic curve was performed to investigate the effects on whether to have prediabetes for each factors. Two models were built: Model 1: FPIS + SPIS, and Model 2: model 1 + GE. The area under the receiver operating characteristic (aROC) curve was used to determine the predictive power of these models.The aROC curve of GE was significantly higher than the diagonal line followed by SPIS and FPIS accordingly. The aROC curve of Model 1 (0.611) was not different from GE. However, Model 2 improved significantly up to 0.663. Based on this model, an equation was built (-0.003 × GE - 212.6 × SPIS - 17.9 × insulin resistance + 4.8). If the calculated value is equal or higher than 0 (≥0), then the subject has higher chance to have prediabetes (sensitivity = 0.607, specificity = 0.635).Among the 4 factors, GE is the most important contributor for prediabetes in older women. By building a model composed of FPIS, SPIS, and GE, the aROC curve increased significantly. The equation built from this model could predict prediabetes precisely.
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Affiliation(s)
- Chieh-Hua Lu
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Tri-Service General Hospital, National Defense Medical Center
- Department of Medical Research, NDMC, Taipei
| | - Sen-Wen Teng
- Department of Obstetrics and Gynecology, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City
| | - Chung-Ze Wu
- Division of Endocrinology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University
| | - Chang-Hsun Hsieh
- Division of Endocrinology and Metabolism, Department of Internal Medicine
| | - Jin-Biou Chang
- Department of Pathology, National Defense Medical Center, Division of Clinical Pathology, Tri-Service General Hospital, R.O.C
| | - Yen-Lin Chen
- Department of Pathology, Cardinal Tien Hospital, School of Medicine
| | - Yao-Jen Liang
- Associate Dean of College of Science and Engineering, Director of Graduate Institute of Applied Science and Engineering, Department and Institute of Life-Science, Fu-Jen Catholic University, New Taipei City
| | - Po-Shiuan Hsieh
- Department of Medical Research, NDMC, Taipei
- Department of Physiology and Biophysics
- Institute of Preventive Medicine, National Defense Medical Center, Taipei
| | - Dee Pei
- Department of Internal Medicine, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Jiunn-Diann Lin
- Division of Endocrinology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University
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Consitt LA, Dudley C, Saxena G. Impact of Endurance and Resistance Training on Skeletal Muscle Glucose Metabolism in Older Adults. Nutrients 2019; 11:nu11112636. [PMID: 31684154 PMCID: PMC6893763 DOI: 10.3390/nu11112636] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/14/2019] [Accepted: 10/18/2019] [Indexed: 12/20/2022] Open
Abstract
Aging is associated with insulin resistance and the development of type 2 diabetes. While this process is multifaceted, age-related changes to skeletal muscle are expected to contribute to impaired glucose metabolism. Some of these changes include sarcopenia, impaired insulin signaling, and imbalances in glucose utilization. Endurance and resistance exercise training have been endorsed as interventions to improve glucose tolerance and whole-body insulin sensitivity in the elderly. While both types of exercise generally increase insulin sensitivity in older adults, the metabolic pathways through which this occurs can differ and can be dependent on preexisting conditions including obesity and type 2 diabetes. In this review, we will first highlight age-related changes to skeletal muscle which can contribute to insulin resistance, followed by a comparison of endurance and resistance training adaptations to insulin-stimulated glucose metabolism in older adults.
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Affiliation(s)
- Leslie A Consitt
- Department of Biomedical Sciences, Ohio University, Athens, OH 45701, USA.
- Ohio Musculoskeletal and Neurological Institute, Ohio University, Athens, OH 45701, USA.
- Diabetes Institute, Ohio University, Athens, OH 45701, USA.
| | - Courtney Dudley
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Gunjan Saxena
- Department of Biomedical Sciences, Ohio University, Athens, OH 45701, USA.
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Bonzón-Kulichenko E, Moltó E, Pintado C, Fernández A, Arribas C, Schwudke D, Gallardo N, Shevchenko A, Andrés A. Changes in Visceral Adipose Tissue Plasma Membrane Lipid Composition in Old Rats Are Associated With Adipocyte Hypertrophy With Aging. J Gerontol A Biol Sci Med Sci 2019; 73:1139-1146. [PMID: 29668887 DOI: 10.1093/gerona/gly081] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 04/13/2018] [Indexed: 12/17/2022] Open
Abstract
Increased adiposity, through adipocyte hypertrophy, and/or hyperplasia, characterizes aging and obesity. Both are leptin-resistant states, associated with disturbed lipid metabolism, reduced insulin sensitivity and inflammation. Nevertheless, fat tissue dysfunction appears earlier in obesity than in normal aging. In contrast, lipodystrophy is accompanied by diabetes, and improving the fat cell capacity to expand rescues the diabetic phenotype. Fat tissue dysfunction is extensively studied in the diet-induced obesity, but remains relatively neglected in the aging-associated obesity. In the Wistar rat, as occurs in humans, early or middle aging is accompanied by an increase in adiposity. Using this experimental model, we describe the molecular mechanisms contributing to the white adipose tissue (WAT) hypertrophy. WAT from middle-old age rats is characterized by decreased basal lipogenesis and lipolysis, increased esterification, as demonstrated by the higher TAG and cholesterol content in visceral WAT, and the maintenance of total ceramide levels within normal values. In addition, we describe alterations in the adipose tissue plasma membrane lipid composition, as increased total ether-phosphatidylcholine, sphingomyelin, and free cholesterol levels that favor an enlarged fat cell size with aging. All these metabolic changes may be regarded as a survival advantage that prevents the aged rats from becoming overtly diabetic.
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Affiliation(s)
- Elena Bonzón-Kulichenko
- Área de Bioquímica, Facultad de Ciencias y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Eduardo Moltó
- Área de Bioquímica, Facultad de Ciencias Medioambientales y Bioquímica, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Toledo, Spain
| | - Cristina Pintado
- Área de Bioquímica, Facultad de Ciencias Medioambientales y Bioquímica, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Toledo, Spain
| | - Alejandro Fernández
- Área de Bioquímica, Facultad de Ciencias y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Carmen Arribas
- Área de Bioquímica, Facultad de Ciencias Medioambientales y Bioquímica, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Toledo, Spain
| | - Dominik Schwudke
- Division of Bioanalytical Chemistry, Priority Area Infections, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Germany
| | - Nilda Gallardo
- Área de Bioquímica, Facultad de Ciencias y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Antonio Andrés
- Área de Bioquímica, Facultad de Ciencias y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain
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9
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Iizuka Y, Kim H, Hirako S, Chiba K, Wada M, Matsumoto A. Benefits of combination low-dose pioglitazone plus fish oil on aged type 2 diabetes mice. J Food Drug Anal 2018; 26:1265-1274. [PMID: 30249325 PMCID: PMC9298570 DOI: 10.1016/j.jfda.2018.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 05/18/2018] [Accepted: 05/25/2018] [Indexed: 01/05/2023] Open
Abstract
The elderly patients with type 2 diabetes suffer more adverse drug events than young adults due to pharmacokinetic and pharmacodynamic changes associated with aging. Reducing the risks of these medication-related problems are equally important for the clinical care of older type 2 diabetes patients. Pioglitazone is used for treating type 2 diabetes as an oral antidiabetic drug. Despite pioglitazone is used helpful insulin sensitizers, the accumulation of subcutaneous fat is considered a major adverse effect of pioglitazone therapy. We investigated to reduce the adverse effect of pioglitazone by combination with fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in aged diabetic KK mice. The accumulation of subcutaneous fat associated with high-dose pioglitazone is reduced by fish oil, suppressing lipogenesis and stimulating fatty acid β-oxidation in the liver. Our data suggest that adding fish oil to low-dose pioglitazone results in anti-diabetic efficacy similar to that of the high-dose without concomitant body weight gain.
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Sierra Rojas JX, García-San Frutos M, Horrillo D, Lauzurica N, Oliveros E, Carrascosa JM, Fernández-Agulló T, Ros M. Differential Development of Inflammation and Insulin Resistance in Different Adipose Tissue Depots Along Aging in Wistar Rats: Effects of Caloric Restriction. J Gerontol A Biol Sci Med Sci 2015; 71:310-22. [DOI: 10.1093/gerona/glv117] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 02/14/2015] [Indexed: 01/06/2023] Open
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11
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Salamanca A, Bárcena B, Arribas C, Fernández-Agulló T, Martínez C, Carrascosa JM, Ros M, Andrés A, Gallardo N. Aging impairs the hepatic subcellular distribution of ChREBP in response to fasting/feeding in rats: Implications on hepatic steatosis. Exp Gerontol 2015; 69:9-19. [DOI: 10.1016/j.exger.2015.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/08/2015] [Accepted: 05/19/2015] [Indexed: 12/27/2022]
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12
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Amengual-Cladera E, Lladó I, Proenza AM, Gianotti M. Sex dimorphism in the onset of the white adipose tissue insulin sensitivity impairment associated with age. Biochimie 2014; 106:75-80. [DOI: 10.1016/j.biochi.2014.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 08/05/2014] [Indexed: 11/16/2022]
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Ghosh AK, Garg SK, Mau T, O'Brien M, Liu J, Yung R. Elevated Endoplasmic Reticulum Stress Response Contributes to Adipose Tissue Inflammation in Aging. J Gerontol A Biol Sci Med Sci 2014; 70:1320-9. [PMID: 25324219 DOI: 10.1093/gerona/glu186] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/08/2014] [Indexed: 12/18/2022] Open
Abstract
Adipose tissue inflammation has been linked to age-related metabolic diseases. However, the underlying mechanisms are poorly understood. Adipose tissue inflammation and insulin resistance in diet associated obesity has been correlated with aberrant endoplasmic reticulum (ER) stress. This study was undertaken to test our hypothesis that increased ER stress response contributes to age-associated adipose tissue inflammation. We found elevated ER stress response in adipose tissue of old (18-20 months) compared to young (4-6 months) mice. Elevated ER stress markers BIP (GRP78), CHOP, cleaved-ATF-6, phospho-IRE1α, and XBP-1 were observed in old compared to young adipose tissue stromal cells. Additionally, old adipose tissue stromal cells were more sensitive to an ER stress inducer, thapsigargin. Similar experiments with adipose tissue macrophages showed elevated Chop and Bip expression in old adipose tissue macrophages when induced with thapsigargin. Treatment of chemical chaperone 4-phenyle-butyric acid alleviated ER stress in adipose tissue stromal cells and adipose tissue macrophages and attenuated the production of IL-6 and MCP-1 by adipose tissue stromal cells, and TNF-α by adipose tissue macrophages from both young and old mice. Finally, old mice fed with 4-phenyle-butyric acid have reduced expression of ER stress and inflammatory cytokine genes. Our data suggests that an exaggerated ER stress response in aging adipose tissue contributes to age-associated inflammation that can be mitigated by treatment with chemical chaperones.
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Affiliation(s)
- Amiya Kumar Ghosh
- Division of Geriatrics and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor
| | - Sanjay Kumar Garg
- Division of Geriatrics and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor
| | - Theresa Mau
- Division of Geriatrics and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor
| | - Martin O'Brien
- Division of Geriatrics and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor
| | - Jianhua Liu
- Division of Geriatrics and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor
| | - Raymond Yung
- Division of Geriatrics and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor. Geriatric Research, Education and Clinical Care Center (GRECC), VA Ann Arbor Health System, Michigan.
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14
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She M, Hou H, Wang Z, Zhang C, Laudon M, Yin W. Melatonin rescues 3T3-L1 adipocytes from FFA-induced insulin resistance by inhibiting phosphorylation of IRS-1 on Ser307. Biochimie 2014; 103:126-30. [PMID: 24846082 DOI: 10.1016/j.biochi.2014.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 05/04/2014] [Indexed: 11/18/2022]
Abstract
Melatonin is biosynthesized in the pineal gland and secreted into the bloodstream. Evidences indicate a role of melatonin in the regulation of glucose metabolism. The objective of this study was to investigate the effect of melatonin on insulin sensitivity in insulin resistant adipocytes. Following a preincubation with melatonin or vehicle for 30 min, insulin resistant cells of 3T3-L1 adipocytes were induced by palmitic acids (300 μM, 6 h). Our results showed that palmitic acids inhibited both the basal and insulin-stimulated uptake of [(3)H]-2-Deoxyglucose, down-regulated the levels of IRS-1 and GLUT-4. However, compared to the vehicle group, melatonin pre-treatment increased significantly the uptake of [(3)H]-2-Deoxyglucose as well as the level of GLUT-4, and decreased phosphorylated IRS-1 (Ser307) although total IRS-1 did not change significantly. These data suggest that palmitic acids impair insulin signal via down-regulating the expressions of IRS-1 and GLUT-4; whereas melatonin can ameliorate insulin sensitivity by inhibiting Ser307 phosphorylation in IRS-1 and increasing GLUT-4 expressions in insulin resistant 3T3-L1 adipocytes. We conclude that melatonin regulates the insulin sensitivity and glucose homeostasis via inhibiting Ser-phosphorylation and improving function of IRS-1.
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Affiliation(s)
- Meihua She
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, University of South China, Hengyang, China; Department of Biochemistry and Molecular Biology, University of South China, Hengyang, China
| | - Hongjie Hou
- Department of Biochemistry and Molecular Biology, University of South China, Hengyang, China
| | - Zongbao Wang
- Department of Laboratory Animal Science, University of South China, Hengyang, China
| | - Chi Zhang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, University of South China, Hengyang, China
| | - Moshe Laudon
- Drug Discovery, Neurim Pharmaceuticals Ltd., Tel-Aviv, Israel
| | - Weidong Yin
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, University of South China, Hengyang, China; Department of Biochemistry and Molecular Biology, University of South China, Hengyang, China.
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15
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Johari SM, Shahar S. Metabolic syndrome: The association of obesity and unhealthy lifestyle among Malaysian elderly people. Arch Gerontol Geriatr 2014; 59:360-6. [PMID: 24882592 DOI: 10.1016/j.archger.2014.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 04/08/2014] [Accepted: 04/24/2014] [Indexed: 11/30/2022]
Abstract
The aim of this study is to investigate the prevalence of metabolic syndrome (MetS) and its predictors among Malaysian elderly. A total of 343 elderly aged ≥ 60 years residing low cost flats in an urban area in the central of Malaysia were invited to participate in health screening in community centers. Subjects were interviewed to obtain socio demography, health status and behavior data. Anthropometric measurements were also measured. A total of 30 ml fasting blood was taken to determine fasting serum lipid, glucose level and oxidative stress. MetS was classified according to The International Diabetes Federation (IDF) criteria. The prevalence of MetS was 43.4%. More women (48.1%) were affected than men (36.3%) (p<0.05). Being obese or overweight was the strongest predictor for MetS in men and women (p<0.05, both gender). High carbohydrate intake increased risk of MetS in men by 2.8 folds. In women, higher fat free mass index, physical inactivity and good appetite increased risk of MetS by 3.9, 2.1 and 2.3 folds respectively. MetS affected almost half of Malaysian elderly being investigated, especially women, and is associated with obesity and unhealthy lifestyle. It is essential to develop preventive and intervention strategies to curb undesirable consequences associated with MetS.
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Affiliation(s)
- Sa'ida Munira Johari
- Dietetic Program, School of Healthcare Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Suzana Shahar
- Dietetic Program, School of Healthcare Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
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Zanuto R, Siqueira-Filho MA, Caperuto LC, Bacurau RFP, Hirata E, Peliciari-Garcia RA, do Amaral FG, Marçal AC, Ribeiro LM, Camporez JPG, Carpinelli AR, Bordin S, Cipolla-Neto J, Carvalho CRO. Melatonin improves insulin sensitivity independently of weight loss in old obese rats. J Pineal Res 2013; 55:156-65. [PMID: 23565768 DOI: 10.1111/jpi.12056] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/22/2013] [Indexed: 12/29/2022]
Abstract
In aged rats, insulin signaling pathway (ISP) is impaired in tissues that play a pivotal role in glucose homeostasis, such as liver, skeletal muscle, and adipose tissue. Moreover, the aging process is also associated with obesity and reduction in melatonin synthesis from the pineal gland and other organs. The aim of the present work was to evaluate, in male old obese Wistar rats, the effect of melatonin supplementation in the ISP, analyzing the total protein amount and the phosphorylated status (immunoprecipitation and immunoblotting) of the insulin cascade components in the rat hypothalamus, liver, skeletal muscle, and periepididymal adipose tissue. Melatonin was administered in the drinking water for 8- and 12 wk during the night period. Food and water intake and fasting blood glucose remained unchanged. The insulin sensitivity presented a 2.1-fold increase both after 8- and 12 wk of melatonin supplementation. Animals supplemented with melatonin for 12 wk also presented a reduction in body mass. The acute insulin-induced phosphorylation of the analyzed ISP proteins increased 1.3- and 2.3-fold after 8- and 12 wk of melatonin supplementation. The total protein content of the insulin receptor (IR) and the IR substrates (IRS-1, 2) remained unchanged in all investigated tissues, except for the 2-fold increase in the total amount of IRS-1 in the periepididymal adipose tissue. Therefore, the known age-related melatonin synthesis reduction may also be involved in the development of insulin resistance and the adequate supplementation could be an important alternative for the prevention of insulin signaling impairment in aged organisms.
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Affiliation(s)
- Ricardo Zanuto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences-I, University of São Paulo USP, São Paulo, SP, Brazil
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17
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García-Salcedo JJ, Recio-Vega R, Serrano-Gallardo LB, Calderón-Salinas V. Homeostasis model assessment in elderly adults without diabetes mellitus. J Am Geriatr Soc 2013; 61:1228-9. [PMID: 23855857 DOI: 10.1111/jgs.12342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Sardinha FLC, Fernandes FS, Tavares do Carmo MG, Herrera E. Sex-dependent nutritional programming: fish oil intake during early pregnancy in rats reduces age-dependent insulin resistance in male, but not female, offspring. Am J Physiol Regul Integr Comp Physiol 2013; 304:R313-20. [DOI: 10.1152/ajpregu.00392.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Prenatal and early postnatal nutritional status may predispose offspring to impaired glucose tolerance and changes in insulin sensitivity in adult life. The long-term consequences of changes in maternal dietary fatty acid composition were determined in rats. From day 1 until day 12 of pregnancy, rats were given isocaloric diets containing 9% nonvitamin fat based on soybean, olive, fish (FO), linseed, or palm oil. Thereafter, they were maintained on the standard diet; offspring were studied at different ages. Body weight at 4, 8, and 12 mo and lumbar adipose tissue and liver weights at 12 mo did not differ between females on the different diets, whereas in males the corresponding values were all lower in the offspring from the FO group compared with the other dietary groups. Plasma glucose concentrations (both basal and after an oral glucose load) did not change with sex or dietary group, but plasma insulin concentrations were lower in females than in males and, in males, were lowest in the FO group. Similar relations were found with both the homeostasis model assessment of insulin resistance and insulin sensitivity index. In conclusion, the intake of more n–3 fatty acids (FO diet) during early pregnancy reduced both fat accretion and age-related decline in insulin sensitivity in male offspring but not in females. It is proposed that the lower adiposity caused by the increased n–3 fatty acids during the intrauterine life was responsible of the lower insulin resistance in male offspring.
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Affiliation(s)
- Fatima L. C. Sardinha
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; and
| | - Flavia S. Fernandes
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; and
| | - Maria G. Tavares do Carmo
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; and
| | - Emilio Herrera
- Faculty of Pharmacy, University of San Pablo-CEU, Madrid, Spain
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De Solís AJ, Fernández-Agulló T, García-SanFrutos M, Pérez-Pardo P, Bogónez E, Andrés A, Ros M, Carrascosa JM. Impairment of skeletal muscle insulin action with aging in Wistar rats: Role of leptin and caloric restriction. Mech Ageing Dev 2012; 133:306-16. [DOI: 10.1016/j.mad.2012.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 02/13/2012] [Accepted: 03/06/2012] [Indexed: 01/04/2023]
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20
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Nadal-Casellas A, Proenza AM, Lladó I, Gianotti M. Sex-dependent differences in rat hepatic lipid accumulation and insulin sensitivity in response to diet-induced obesity. Biochem Cell Biol 2012; 90:164-72. [PMID: 22235846 DOI: 10.1139/o11-069] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Ectopic deposition of lipids in liver and other extrahepatic tissues alters their function and occurs once adipose tissue fat storage capacity is exceeded. We investigated sexual dimorphism in the effects of dietary obesity on the liver insulin signaling pathway, as well as its connection to differences in hepatic fat accumulation. Ten-week-old Wistar rats of both sexes were fed a standard diet or a high-fat diet for 26 weeks. Insulin, adipokine levels, and glucose tolerance were measured. Lipid content, PPARα mRNA expression and protein levels of insulin receptor subunit β (IRβ), IR substrate 2 (IRS-2), Ser/Thr kinase A (Akt), and pyruvate dehydrogenase kinase isozyme 4 (PDK4) were measured in liver. In control rats, serum parameters and hepatic levels of IRβ, IRS-2, and Akt proteins pointed to a profile of better insulin sensitivity in females. In response to dietary treatment, female rats exhibited a greater increase in body mass and adiposity and lower liver fat accumulation than males, but maintained better glucose tolerance. The reduced insulin signaling capacity in the liver of obese female rats seems to prevent lipid accumulation and probably lipotoxicity-associated hepatic disorders.
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Affiliation(s)
- Antònia Nadal-Casellas
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Cra. Valldemossa km 7.5. E-07122 Palma de Mallorca, Spain
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21
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Avenatti R. The intersection of inflammation, insulin resistance and ageing: implications for the study of molecular signalling pathways in horses. COMPARATIVE EXERCISE PHYSIOLOGY 2012. [DOI: 10.3920/cep12018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Inflammation-associated insulin resistance contributes to chronic disease in humans and other long-lived species, such as horses. Insulin resistance arises due to an imbalance among molecular signalling mediators in response to pro-inflammatory cytokines in the aged and obese. The mammalian heat shock protein response has received much attention as an avenue for attenuating inflammatory mediator signalling and for contributing to preservation and restoration of insulin signalling in metabolically important tissues. Data on heat shock proteins and inflammatory signalling mediators in untrained and aged horses are lacking, and horses represent an untapped resource for studying the mediator imbalance contributing to insulin resistance in a comparative model.
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Affiliation(s)
- R.C. Avenatti
- Rutgers Equine Science Center, Rutgers, the State University of New Jersey, 57 U.S. Highway 1, New Brunswick, NJ 08850, USA
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22
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Billaud M, Ross JA, Greyson MA, Bruce AC, Seaman SA, Heberlein KR, Han J, Best AK, Peirce SM, Isakson BE. A new method for in vivo visualization of vessel remodeling using a near-infrared dye. Microcirculation 2011; 18:163-71. [PMID: 21418375 DOI: 10.1111/j.1549-8719.2011.00085.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Vascular obstructive events can be partially compensated for by remodeling processes that increase vessel diameter and collateral tortuosity. However, methods for visualizing remodeling events in vivo and with temporal comparisons from the same animal remain elusive. METHODS Using a novel infrared conjugated polyethylene glycol dye, we investigated the possibility of intravital vascular imaging of the mouse ear before and after ligation of the primary feeder artery. For comparison, we used two different mouse models known to have impaired vascular remodeling after ligation (i.e., aged and PAI-1(-/-) mice). The results obtained with the infrared dye were confirmed using immunofluorescence labeling of the ear microvasculature with confocal microscopy. RESULTS After ligation, increases in vessel diameter (between 10% and 60%) and tortuosity (approximately 15%) were observed in C57Bl/6 mice using both the infrared dye and the immunofluorescence technique. However, aged C57Bl/6 and PAI-1(-/-) mice did not show vascular remodeling following ligation. CONCLUSIONS Vascular remodeling can be visualized and accurately quantified using a new infrared dye in vivo. This analysis technique could be generally employed for quantitative investigations of changes in vascular remodeling.
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Affiliation(s)
- Marie Billaud
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
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23
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Horrillo D, Sierra J, Arribas C, García-San Frutos M, Carrascosa JM, Lauzurica N, Fernández-Agulló T, Ros M. Age-associated development of inflammation in Wistar rats: Effects of caloric restriction. Arch Physiol Biochem 2011; 117:140-50. [PMID: 21635187 DOI: 10.3109/13813455.2011.577435] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
CONTEXT Insulin resistance and type 2 Diabetes have been associated to a low grade of inflammation and their prevalence increase with ageing. OBJECTIVE To analyse the development of inflammation in adipose tissue, liver, muscle and hypothalamus during ageing and the effects of caloric restriction. MATERIALS AND METHODS We have analysed the expression of inflammatory cytokines (TNFα, IL1-β, IL-12B and IL-6), proteins involved in macrophage recruitment (MCP-1, CCR2), TLR4 and macrophage markers (CD11c, CD11b and arginase1). Immunohistochemistry of macrophages has also been performed. RESULTS All studied tissues present signs of inflammation during ageing, but with different pattern and intensity. Caloric restriction decreases the expression of most of inflammatory markers. DISCUSSION AND CONCLUSIONS These data indicate a role of adiposity in the development of inflammation and insulin resistance during ageing. Dietetic intervention could be a useful tool to ameliorate the development of inflammation and insulin resistance associated with ageing.
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Affiliation(s)
- Daniel Horrillo
- Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, 28922, Madrid, Spain
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Gómez-Pérez Y, Gianotti M, Proenza AM, Lladó I. Age-Related Decline of Skeletal Muscle Insulin Sensitivity in Rats: Effect of Sex and Muscle Type. Rejuvenation Res 2011; 14:153-61. [DOI: 10.1089/rej.2010.1107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Yolanda Gómez-Pérez
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| | - Magdalena Gianotti
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| | - Ana M. Proenza
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| | - Isabel Lladó
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
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Allard JB, Duan C. Comparative endocrinology of aging and longevity regulation. Front Endocrinol (Lausanne) 2011; 2:75. [PMID: 22654825 PMCID: PMC3356063 DOI: 10.3389/fendo.2011.00075] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 10/28/2011] [Indexed: 01/06/2023] Open
Abstract
Hormones regulate growth, development, metabolism, and other complex processes in multicellular animals. For many years it has been suggested that hormones may also influence the rate of the aging process. Aging is a multifactorial process that causes biological systems to break down and cease to function in adult organisms as time passes, eventually leading to death. The exact underlying causes of the aging process remain a topic for debate, and clues that may shed light on these causes are eagerly sought after. In the last two decades, gene mutations that result in delayed aging and extended longevity have been discovered, and many of the affected genes have been components of endocrine signaling pathways. In this review we summarize the current knowledge on the roles of endocrine signaling in the regulation of aging and longevity in various animals. We begin by discussing the notion that conserved systems, including endocrine signaling pathways, "regulate" the aging process. Findings from the major model organisms: worms, flies, and rodents, are then outlined. Unique lessons from studies of non-traditional models: bees, salmon, and naked mole rats, are also discussed. Finally, we summarize the endocrinology of aging in humans, including changes in hormone levels with age, and the involvement of hormones in aging-related diseases. The most well studied and widely conserved endocrine pathway that affects aging is the insulin/insulin-like growth factor system. Mutations in genes of this pathway increase the lifespan of worms, flies, and mice. Population genetic evidence also suggests this pathway's involvement in human aging. Other hormones including steroids have been linked to aging only in a subset of the models studied. Because of the value of comparative studies, it is suggested that the aging field could benefit from adoption of additional model organisms.
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Affiliation(s)
- John B. Allard
- Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MI, USA
| | - Cunming Duan
- Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MI, USA
- *Correspondence: Cunming Duan, Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Natural Science Building, Ann Arbor, MI 48109, USA. e-mail:
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