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Pollard AE. New concepts in the roles of AMPK in adipocyte stem cell biology. Essays Biochem 2024:EBC20240008. [PMID: 39175418 DOI: 10.1042/ebc20240008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 08/09/2024] [Accepted: 08/13/2024] [Indexed: 08/24/2024]
Abstract
Obesity is a major risk factor for many life-threatening diseases. Adipose tissue dysfunction is emerging as a driving factor in the transition from excess adiposity to comorbidities such as metabolic-associated fatty liver disease, cardiovascular disease, Type 2 diabetes and cancer. However, the transition from healthy adipose expansion to the development of these conditions is poorly understood. Adipose stem cells, residing in the vasculature and stromal regions of subcutaneous and visceral depots, are responsible for the expansion and maintenance of organ function, and are now recognised as key mediators of pathological transformation. Impaired tissue expansion drives inflammation, dysregulation of endocrine function and the deposition of lipids in the liver, muscle and around vital organs, where it is toxic. Contrary to previous hypotheses, it is the promotion of healthy adipose tissue expansion and function, not inhibition of adipogenesis, that presents the most attractive therapeutic strategy in the treatment of metabolic disease. AMP-activated protein kinase, a master regulator of energy homeostasis, has been regarded as one such target, due to its central role in adipose tissue lipid metabolism, and its apparent inhibition of adipogenesis. However, recent studies utilising AMP-activated protein kinase (AMPK)-specific compounds highlight a more subtle, time-dependent role for AMPK in the process of adipogenesis, and in a previously unexplored repression of leptin, independent of adipocyte maturity. In this article, I discuss historic evidence for AMPK-mediated adipogenesis inhibition and the multi-faceted roles for AMPK in adipose tissue.
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Affiliation(s)
- Alice E Pollard
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, U.K
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2
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Rosano C, Karikari TK, Cvejkus R, Bellaver B, Ferreira PCL, Zmuda J, Wheeler V, Pascoal TA, Miljkovic I. Sex differences in Alzheimer's disease blood biomarkers in a Caribbean population of African ancestry: The Tobago Health Study. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2024; 10:e12460. [PMID: 38617114 PMCID: PMC11010267 DOI: 10.1002/trc2.12460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/02/2024] [Accepted: 02/09/2024] [Indexed: 04/16/2024]
Abstract
INTRODUCTION Alzheimer's disease (AD) is increasing in the Caribbean, especially for persons of African ancestry (PAA) and women. However, studies have mostly utilized surveys without AD biomarkers. METHODS In the Tobago Health Study (n = 309; 109 women, mean age 70.3 ± 6.6), we assessed sex differences and risk factors for serum levels of phosphorylated tau-181 (p-tau181), amyloid-beta (Aβ)42/40 ratio, glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL). Blood samples were from 2010 to 2013 for men and from 2019 to 2023 for women. RESULTS Women were more obese, hypertensive, and sedentary but reported less smoking and alcohol use than men (age-adjusted p < 0.04). Compared to men, women had worse levels of AD biomarkers, with higher p-tau181 and lower Aβ42/40, independent of covariates (p < 0.001). In sex-stratified analyses, higher p-tau181 was associated with older age in women and with hypertension in men. GFAP and NfL did not differ by sex. DISCUSSION Women had worse AD biomarkers than men, unexplained by age, cardiometabolic diseases, or lifestyle. Studying risk factors for AD in PAA is warranted, especially for women earlier in life.
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Affiliation(s)
- Caterina Rosano
- Department of EpidemiologySchool of Public HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Thomas K. Karikari
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of Psychiatry and NeurochemistryInstitute of Neuroscience and PhysiologyThe Sahlgrenska AcademyUniversity of GothenburgGothenburgSweden
| | - Ryan Cvejkus
- Department of EpidemiologySchool of Public HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Bruna Bellaver
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | | | - Joseph Zmuda
- Department of EpidemiologySchool of Public HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Victor Wheeler
- Tobago Health Studies OfficeScarboroughTobagoTrinidad and Tobago
| | - Tharick A. Pascoal
- Department of NeurologySchool of MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Iva Miljkovic
- Department of EpidemiologySchool of Public HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
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Agius R, Pace NP, Fava S. Phenotyping obesity: A focus on metabolically healthy obesity and metabolically unhealthy normal weight. Diabetes Metab Res Rev 2024; 40:e3725. [PMID: 37792999 DOI: 10.1002/dmrr.3725] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 07/23/2023] [Accepted: 08/11/2023] [Indexed: 10/06/2023]
Abstract
Over the past 4 decades, research has shown that having a normal body weight does not automatically imply preserved metabolic health and a considerable number of lean individuals harbour metabolic abnormalities typically associated with obesity. Conversely, excess adiposity does not always equate with an abnormal metabolic profile. In fact, evidence exists for the presence of a metabolically unhealthy normal weight (MUHNW) and a metabolically healthy obese (MHO) phenotype. It has become increasingly recognised that different fat depots exert different effects on the metabolic profile of each individual by virtue of their location, structure and function, giving rise to these different body composition phenotypes. Furthermore, other factors have been implicated in the aetiopathogenesis of the body composition phenotypes, including genetics, ethnicity, age and lifestyle/behavioural factors. Even though to date both MHO and MUHNW have been widely investigated and documented in the literature, studies report different outcomes on long-term cardiometabolic morbidity and mortality. Future large-scale, observational and population-based studies are required for better profiling of these phenotypes as well as to further elucidate the pathophysiological role of the adipocyte in the onset of metabolic disorders to allow for better risk stratification and a personalised treatment paradigm.
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Affiliation(s)
- Rachel Agius
- University of Malta Medical School, Msida, Malta
- Mater Dei Hospital, Msida, Malta
| | | | - Stephen Fava
- University of Malta Medical School, Msida, Malta
- Mater Dei Hospital, Msida, Malta
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Miles LA, Bai H, Chakrabarty S, Baik N, Zhang Y, Parmer RJ, Samad F. Overexpression of Plg-R KT protects against adipose dysfunction and dysregulation of glucose homeostasis in diet-induced obese mice. Adipocyte 2023; 12:2252729. [PMID: 37642146 PMCID: PMC10481882 DOI: 10.1080/21623945.2023.2252729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 08/31/2023] Open
Abstract
The plasminogen receptor, Plg-RKT, is a unique cell surface receptor that is broadly expressed in cells and tissues throughout the body. Plg-RKT localizes plasminogen on cell surfaces and promotes its activation to the broad-spectrum serine protease, plasmin. In this study, we show that overexpression of Plg-RKT protects mice from high fat diet (HFD)-induced adipose and metabolic dysfunction. During the first 10 weeks on the HFD, the body weights of mice that overexpressed Plg-RKT (Plg-RKT-OEX) were lower than those of control mice (CagRosaPlgRKT). After 10 weeks on the HFD, CagRosaPlgRKT and Plg-RKT-OEX mice had similar body weights. However, Plg-RKT-OEX mice showed a more metabolically favourable body composition phenotype. Plg-RKT-OEX mice also showed improved glucose tolerance and increased insulin sensitivity. We found that the improved metabolic functions of Plg-RKT-OEX mice were mechanistically associated with increased energy expenditure and activity, decreased proinflammatory adipose macrophages and decreased inflammation, elevated brown fat thermogenesis, and higher expression of adipose PPARγ and adiponectin. These findings suggest that Plg-RKT signalling promotes healthy adipose function via multiple mechanisms to defend against obesity-associated adverse metabolic phenotypes.
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Affiliation(s)
- Lindsey A. Miles
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Hongdong Bai
- Department of Medicine, Veterans Administration San Diego Healthcare System, San Diego, CA, USA
| | - Sagarika Chakrabarty
- Department of Cell Biology, San Diego Biomedical Research Institute, San Diego, CA, USA
| | - Nagyung Baik
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Yuqing Zhang
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Robert J. Parmer
- Department of Medicine, Veterans Administration San Diego Healthcare System, San Diego, CA, USA
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Fahumiya Samad
- Department of Cell Biology, San Diego Biomedical Research Institute, San Diego, CA, USA
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Nutrients, Physical Activity, and Mitochondrial Dysfunction in the Setting of Metabolic Syndrome. Nutrients 2023; 15:nu15051217. [PMID: 36904216 PMCID: PMC10004804 DOI: 10.3390/nu15051217] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/04/2023] Open
Abstract
Metabolic syndrome (MetS) is a cluster of metabolic risk factors for diabetes, coronary heart disease, non-alcoholic fatty liver disease, and some tumors. It includes insulin resistance, visceral adiposity, hypertension, and dyslipidemia. MetS is primarily linked to lipotoxicity, with ectopic fat deposition from fat storage exhaustion, more than obesity per se. Excessive intake of long-chain saturated fatty acid and sugar closely relates to lipotoxicity and MetS through several pathways, including toll-like receptor 4 activation, peroxisome proliferator-activated receptor-gamma regulation (PPARγ), sphingolipids remodeling, and protein kinase C activation. These mechanisms prompt mitochondrial dysfunction, which plays a key role in disrupting the metabolism of fatty acids and proteins and in developing insulin resistance. By contrast, the intake of monounsaturated, polyunsaturated, and medium-chain saturated (low-dose) fatty acids, as well as plant-based proteins and whey protein, favors an improvement in sphingolipid composition and metabolic profile. Along with dietary modification, regular exercises including aerobic, resistance, or combined training can target sphingolipid metabolism and improve mitochondrial function and MetS components. This review aimed to summarize the main dietary and biochemical aspects related to the physiopathology of MetS and its implications for mitochondrial machinery while discussing the potential role of diet and exercise in counteracting this complex clustering of metabolic dysfunctions.
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Straat ME, Jurado-Fasoli L, Ying Z, Nahon KJ, Janssen LG, Boon MR, Grabner GF, Kooijman S, Zimmermann R, Giera M, Rensen PC, Martinez-Tellez B. Cold exposure induces dynamic changes in circulating triacylglycerol species, which is dependent on intracellular lipolysis: A randomized cross-over trial. EBioMedicine 2022; 86:104349. [PMID: 36371986 PMCID: PMC9663865 DOI: 10.1016/j.ebiom.2022.104349] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 10/20/2022] [Accepted: 10/20/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The application of cold exposure has emerged as an approach to enhance whole-body lipid catabolism. The global effect of cold exposure on the lipidome in humans has been reported with mixed results depending on intensity and duration of cold. METHODS This secondary study was based on data from a previous randomized cross-over trial (ClinicalTrials.gov ID: NCT03012113). We performed sequential lipidomic profiling in serum during 120 min cold exposure of human volunteers. Next, the intracellular lipolysis was blocked in mice (eighteen 10-week-old male wild-type mice C57BL/6J) using a small-molecule inhibitor of adipose triglyceride lipase (ATGL; Atglistatin), and mice were exposed to cold for a similar duration. The quantitative lipidomic profiling was assessed in-depth using the Lipidyzer platform. FINDINGS In humans, cold exposure gradually increased circulating free fatty acids reaching a maximum at 60 min, and transiently decreased total triacylglycerols (TAGs) only at 30 min. A broad range of TAG species was initially decreased, in particular unsaturated and polyunsaturated TAG species with ≤5 double bonds, while after 120 min a significant increase was observed for polyunsaturated TAG species with ≥6 double bonds in humans. The mechanistic study in mice revealed that the cold-induced increase in polyunsaturated TAGs was largely prevented by blocking adipose triglyceride lipase. INTERPRETATION We interpret these findings as that cold exposure feeds thermogenic tissues with TAG-derived fatty acids for combustion, resulting in a decrease of circulating TAG species, followed by increased hepatic production of polyunsaturated TAG species induced by liberation of free fatty acids stemming from adipose tissue. FUNDING This work was supported by the Netherlands CardioVascular Research Initiative: 'the Dutch Heart Foundation, Dutch Federation of University Medical Centers, the Netherlands Organisation for Health Research and Development and the Royal Netherlands Academy of Sciences' [CVON2017-20 GENIUS-II] to Patrick C.N. Rensen. Borja Martinez-Tellez is supported by individual postdoctoral grant from the Fundación Alfonso Martin Escudero and by a Maria Zambrano fellowship by the Ministerio de Universidades y la Unión Europea - NextGenerationEU (RR_C_2021_04). Lucas Jurado-Fasoli was supported by an individual pre-doctoral grant from the Spanish Ministry of Education (FPU19/01609) and with an Albert Renold Travel Fellowship from the European Foundation for the Study of Diabetes (EFSD). Martin Giera was partially supported by NWO XOmics project #184.034.019.
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Affiliation(s)
- Maaike E. Straat
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Lucas Jurado-Fasoli
- PROmoting FITness and Health Through Physical Activity Research Group (PROFITH), Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
| | - Zhixiong Ying
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Kimberly J. Nahon
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Laura G.M. Janssen
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Mariëtte R. Boon
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Gernot F. Grabner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Sander Kooijman
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Martin Giera
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, the Netherlands
| | - Patrick C.N. Rensen
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands,Corresponding author. Albinusdreef 2, 2333 ZA, Leiden, the Netherlands.
| | - Borja Martinez-Tellez
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
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Novel Insights in the Physiopathology and Management of Obesity-Related Kidney Disease. Nutrients 2022; 14:nu14193937. [PMID: 36235590 PMCID: PMC9572176 DOI: 10.3390/nu14193937] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 11/30/2022] Open
Abstract
Obesity is recognized as an independent risk factor for the development of kidney disease, which has led to the designation of obesity-related glomerulopathy (ORG). Common renal features observed in this condition include glomerular hypertrophy, glomerulosclerosis, haemodynamic changes and glomerular filtration barrier defects. Additionally, and although less studied, obesity-related kidney disease also involves alterations in renal tubules, including tubule hypertrophy, lipid deposition and tubulointerstitial fibrosis. Although not completely understood, the harmful effects of obesity on the kidney may be mediated by different mechanisms, with alterations in adipose tissue probably playing an important role. An increase in visceral adipose tissue has classically been associated with the development of kidney damage, however, recent studies point to adipose tissue surrounding the kidney, and specifically to the fat within the renal sinus, as potentially involved in the development of ORG. In addition, new strategies for the treatment of patients with obesity-related kidney disease are focusing on the management of obesity. In this regard, some non-invasive options, such as glucagon-like peptide-1 (GLP-1) receptor agonists or sodium–glucose cotransporter-2 (SGLT2) inhibitors, are being considered for application in the clinic, not only for patients with diabetic kidney disease but as a novel pharmacological strategy for patients with ORG. In addition, bariatric surgery stands as one of the most effective options, not only for weight loss but also for the improvement of kidney outcomes in obese patients with chronic kidney disease.
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Pasco JA, Sui SX, West EC, Anderson KB, Rufus-Membere P, Tembo MC, Hyde NK, Williams LJ, Liu ZSJ, Kotowicz MA. Fatty Liver Index and Skeletal Muscle Density. Calcif Tissue Int 2022; 110:649-657. [PMID: 35028685 PMCID: PMC9108103 DOI: 10.1007/s00223-021-00939-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/22/2021] [Indexed: 12/25/2022]
Abstract
Accumulation of fat in the liver and skeletal muscle is associated with obesity and poor health outcomes. Liver steatosis is a characteristic of non-alcoholic fatty liver disease (NAFLD) and myosteatosis, of poor muscle quality in sarcopenia. In this study of 403 men (33-96 years), we investigated associations between the fatty liver index (FLI) and muscle density, as markers of fat accumulation in these organs. We also investigated associations between the FLI and parameters of sarcopenia, including DXA-derived appendicular lean mass (ALM) and handgrip strength by dynamometry. Muscle density was measured using pQCT at the radius and tibia. FLI was calculated from BMI, waist circumference, and levels of triglycerides and gamma-glutamyltransferase. There was a pattern of decreasing muscle density across increasing quartiles of FLI. After adjusting for age and lifestyle, mean radial muscle density in Q4 was 2.1% lower than Q1 (p < 0.001) and mean tibial muscle density was 1.8% lower in Q3 and 3.0% lower in Q4, compared to Q1 (p = 0.022 and < 0.001, respectively). After adjusting for age and sedentary lifestyle, participants in the highest FLI quartile were sixfold more likely to have sarcopenia. In conclusion, our results suggest that fat accumulation in the liver co-exists with fat infiltration into skeletal muscle.
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Affiliation(s)
- Julie A. Pasco
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
- Department of Medicine – Western Health, The University of Melbourne, St Albans, VIC Australia
- Barwon Health, Geelong, VIC Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC Australia
| | - Sophia X. Sui
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Emma C. West
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Kara B. Anderson
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Pamela Rufus-Membere
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Monica C. Tembo
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Natalie K. Hyde
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Lana J. Williams
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Zoe S. J. Liu
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
| | - Mark A. Kotowicz
- Deakin University, IMPACT – Institute for Mental and Physical Health and Clinical Translation, Geelong, VIC Australia
- Department of Medicine – Western Health, The University of Melbourne, St Albans, VIC Australia
- Barwon Health, Geelong, VIC Australia
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Lazzer S, D’Alleva M, Vaccari F, Tringali G, De Micheli R, Sartorio A. Effects of a 3-Week Inpatient Multidisciplinary Body Weight Reduction Program on Body Composition and Physical Capabilities in Adolescents and Adults With Obesity. Front Nutr 2022; 9:840018. [PMID: 35433781 PMCID: PMC9008348 DOI: 10.3389/fnut.2022.840018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/18/2022] [Indexed: 12/04/2022] Open
Abstract
Background The aim of the present study was to examine the short-term changes in body composition and physical capabilities in subjects with obesity during a multidisciplinary inpatient body weight reduction program (BWRP). Methods One hundred thirty-nine adolescents (56 boys and 83 girls; BMI: 37.1 ± 6.5 kg/m2; Fat Mass, FM: 45.3 ± 7.2%) and 71 adults (27 males and 44 females; BMI: 44 ± 4.7 kg/m2; FM: 51.4 ± 4.7%) followed a 3-week inpatient BWRP consisting of regular physical activity, moderate energy restriction, nutritional education and psychological counseling. Before (T0) and after the end of the BWRP (T21), body composition was assessed with an impedancemeter, lower limb muscle power with Margaria Stair Climbing Test (SCT), lower limb functionality with Short Physical Performance Battery (SPPB), and the capacity of performing activity of daily living (ADL) with Physical Performance Test (PPT). Results At T21, obese adolescents showed a 4% reduction in body mass (BM) (p < 0.001), associated with a FM reduction in boys (−10%) and girls (−6%) (p < 0.001) and with a 3% reduction in fat-free mass (FFM) recorded only in boys (p = 0.013). Obese adults showed a 5% BM reduction (p < 0.001), associated with a 2% FFM and 9% FM reduction (p < 0.001) in males, and 7% FM reduction in females (p < 0.001). Regarding physical capabilities, at T21 in obese adolescents, PPT score increased by 4% (p < 0.001), SCT decreased by −5% (boys) and −7% (girls) (p < 0.001), while SPPB score did not change significantly. In obese adults at T21, PPT score increased by 9% (p < 0.001), SCT decreased by −16% (p < 0.001) only in females, and SPPB score increased by 7% (males) and 10% (females) (p < 0.01). Conclusion In conclusion, moderate energy restriction and regular physical activity determine a 4-5% BM reduction during a 3-week inpatient BWRP, improve physical capabilities and induce beneficial changes in body composition in adolescents and adults with obesity. Trial registration This study was approved by the Ethical Committee of the Istituto Auxologico Italiano (Milan, Italy; research code: 01C124; acronym: PRORIPONATFIS). Registered 11 November 2020 - Retrospectively registered.
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Affiliation(s)
- Stefano Lazzer
- Department of Medicine, University of Udine, Udine, Italy
- School of Sport Sciences, University of Udine, Udine, Italy
| | - Mattia D’Alleva
- Department of Medicine, University of Udine, Udine, Italy
- School of Sport Sciences, University of Udine, Udine, Italy
- *Correspondence: Mattia D’Alleva,
| | - Filippo Vaccari
- Department of Medicine, University of Udine, Udine, Italy
- School of Sport Sciences, University of Udine, Udine, Italy
| | - Gabriella Tringali
- Experimental Laboratory for Auxo-Endocrinological Research, Istituto Auxologico Italiano, Scientific Institute for Hospitalization and Care (IRCCS), Piancavallo, Italy
| | - Roberta De Micheli
- Experimental Laboratory for Auxo-Endocrinological Research, Istituto Auxologico Italiano, Scientific Institute for Hospitalization and Care (IRCCS), Piancavallo, Italy
| | - Alessandro Sartorio
- Experimental Laboratory for Auxo-Endocrinological Research, Istituto Auxologico Italiano, Scientific Institute for Hospitalization and Care (IRCCS), Piancavallo, Italy
- Division of Auxology, Istituto Auxologico Italiano, Scientific Institute for Hospitalization and Care (IRCCS), Piancavallo, Italy
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Vesga-Jiménez DJ, Martin C, Barreto GE, Aristizábal-Pachón AF, Pinzón A, González J. Fatty Acids: An Insight into the Pathogenesis of Neurodegenerative Diseases and Therapeutic Potential. Int J Mol Sci 2022; 23:2577. [PMID: 35269720 PMCID: PMC8910658 DOI: 10.3390/ijms23052577] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/12/2022] [Accepted: 01/20/2022] [Indexed: 12/13/2022] Open
Abstract
One of the most common lipids in the human body is palmitic acid (PA), a saturated fatty acid with essential functions in brain cells. PA is used by cells as an energy source, besides being a precursor of signaling molecules and protein tilting across the membrane. Although PA plays physiological functions in the brain, its excessive accumulation leads to detrimental effects on brain cells, causing lipotoxicity. This mechanism involves the activation of toll-like receptors (TLR) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways, with the consequent release of pro-inflammatory cytokines, increased production of reactive oxygen species (ROS), endoplasmic reticulum (ER) stress, and autophagy impairment. Importantly, some of the cellular changes induced by PA lead to an augmented susceptibility to the development of Alzheimer's and Parkinson´s diseases. Considering the complexity of the response to PA and the intrinsic differences of the brain, in this review, we provide an overview of the molecular and cellular effects of PA on different brain cells and their possible relationships with neurodegenerative diseases (NDs). Furthermore, we propose the use of other fatty acids, such as oleic acid or linoleic acid, as potential therapeutic approaches against NDs, as these fatty acids can counteract PA's negative effects on cells.
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Affiliation(s)
- Diego Julián Vesga-Jiménez
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogota 110231, Colombia; (D.J.V.-J.); (A.F.A.-P.)
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA 30329, USA;
| | - Cynthia Martin
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA 30329, USA;
| | - George E. Barreto
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland;
- Health Research Institute, University of Limerick, V94 T9PX Limerick, Ireland
| | - Andrés Felipe Aristizábal-Pachón
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogota 110231, Colombia; (D.J.V.-J.); (A.F.A.-P.)
| | - Andrés Pinzón
- Laboratorio de Bioinformática y Biología de Sistemas, Universidad Nacional de Colombia, Bogota 111321, Colombia;
| | - Janneth González
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogota 110231, Colombia; (D.J.V.-J.); (A.F.A.-P.)
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Gupta A, Shamsi F, Altemose N, Dorlhiac GF, Cypess AM, White AP, Yosef N, Patti ME, Tseng YH, Streets A. Characterization of transcript enrichment and detection bias in single-nucleus RNA-seq for mapping of distinct human adipocyte lineages. Genome Res 2022; 32:242-257. [PMID: 35042723 PMCID: PMC8805720 DOI: 10.1101/gr.275509.121] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 12/10/2021] [Indexed: 02/02/2023]
Abstract
Single-cell RNA sequencing (scRNA-seq) enables molecular characterization of complex biological tissues at high resolution. The requirement of single-cell extraction, however, makes it challenging for profiling tissues such as adipose tissue, for which collection of intact single adipocytes is complicated by their fragile nature. For such tissues, single-nucleus extraction is often much more efficient and therefore single-nucleus RNA sequencing (snRNA-seq) presents an alternative to scRNA-seq. However, nuclear transcripts represent only a fraction of the transcriptome in a single cell, with snRNA-seq marked with inherent transcript enrichment and detection biases. Therefore, snRNA-seq may be inadequate for mapping important transcriptional signatures in adipose tissue. In this study, we compare the transcriptomic landscape of single nuclei isolated from preadipocytes and mature adipocytes across human white and brown adipocyte lineages, with whole-cell transcriptome. We show that snRNA-seq is capable of identifying the broad cell types present in scRNA-seq at all states of adipogenesis. However, we also explore how and why the nuclear transcriptome is biased and limited, as well as how it can be advantageous. We robustly characterize the enrichment of nuclear-localized transcripts and adipogenic regulatory lncRNAs in snRNA-seq, while also providing a detailed understanding for the preferential detection of long genes upon using this technique. To remove such technical detection biases, we propose a normalization strategy for a more accurate comparison of nuclear and cellular data. Finally, we show successful integration of scRNA-seq and snRNA-seq data sets with existing bioinformatic tools. Overall, our results illustrate the applicability of snRNA-seq for the characterization of cellular diversity in the adipose tissue.
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Affiliation(s)
- Anushka Gupta
- University of California at Berkeley-University of California at San Francisco Graduate Program in Bioengineering, Berkeley, California 94720, USA
| | - Farnaz Shamsi
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Nicolas Altemose
- University of California at Berkeley-University of California at San Francisco Graduate Program in Bioengineering, Berkeley, California 94720, USA
| | - Gabriel F Dorlhiac
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, California 94720, USA
| | - Aaron M Cypess
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Andrew P White
- Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Nir Yosef
- Center for Computational Biology, University of California, Berkeley, Berkeley, California 94720, USA
- Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720, USA
- Chan Zuckerberg Biohub, San Francisco, California 94158, USA
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University, Cambridge, Massachusetts 02139, USA
| | | | - Yu-Hua Tseng
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02115, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Aaron Streets
- University of California at Berkeley-University of California at San Francisco Graduate Program in Bioengineering, Berkeley, California 94720, USA
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, California 94720, USA
- Chan Zuckerberg Biohub, San Francisco, California 94158, USA
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12
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Miljkovic I, Vella CA, Allison M. Computed Tomography-Derived Myosteatosis and Metabolic Disorders. Diabetes Metab J 2021; 45:482-491. [PMID: 34352985 PMCID: PMC8369205 DOI: 10.4093/dmj.2020.0277] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 06/01/2021] [Indexed: 12/17/2022] Open
Abstract
The role of ectopic adipose tissue infiltration into skeletal muscle (i.e., myosteatosis) for metabolic disorders has received considerable and increasing attention in the last 10 years. The purpose of this review was to evaluate and summarize existing studies focusing on computed tomography (CT)-derived measures of myosteatosis and metabolic disorders. There is consistent evidence that CT-derived myosteatosis contributes to dysglycemia, insulin resistance, type 2 diabetes mellitus, and inflammation, and, to some extent, dyslipidemia, independent of general obesity, visceral fat, and other relevant risk factors, suggesting that it may serve as a tool for metabolic risk prediction. Identification of which muscles should be examined, and the standardized CT protocols to be employed, are necessary to enhance the applicability of findings from epidemiologic studies of myosteatosis. Additional and longer longitudinal studies are necessary to confirm a role of myosteatosis in the development of type 2 diabetes mellitus, and examine these associations in a variety of muscles across multiple race/ethnic populations. Given the emerging role of myosteatosis in metabolic health, well-designed intervention studies are needed to investigate relevant lifestyle and pharmaceutical approaches.
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Affiliation(s)
- Iva Miljkovic
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chantal A. Vella
- Department of Movement Sciences, College of Education, Health and Human Sciences, University of Idaho, Moscow, ID, USA
| | - Matthew Allison
- Department of Family Medicine and Public Health, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Corresponding author: Matthew Allison https://orcid.org/0000-0003-0777-8272 Department of Family Medicine and Public Health, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA E-mail:
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13
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A high lean body mass is not protecting from type 2 diabetes in the presence of a high body fat mass. DIABETES & METABOLISM 2021; 47:101219. [PMID: 33418084 DOI: 10.1016/j.diabet.2020.101219] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 02/01/2023]
Abstract
AIM Most studies examining the associations between body composition and type 2 diabetes have been cross-sectional with prevalent diabetes diagnosis or they have analyzed only fat or lean body mass. Hence, the combined effect of fat and lean body mass on the risk of developing type 2 diabetes remains unclear. We investigated whether baseline lean and fat body mass taken simultaneously into account are associated with incidence of type 2 diabetes over a 15-year follow-up in older adults. METHODS We studied 704 men (n = 297) and women (n = 407) from the Helsinki Birth Cohort Study (mean age 61 years at baseline) without diabetes at baseline. Bioelectrical impedance analysis was used to derive baseline fat mass index (FMI, fat mass/height2) and lean mass index (LMI, lean mass/height2), dichotomized at sex-specific medians. Incident diabetes was defined as the composite of fasting plasma glucose (FPG) ≥ 7.0 mmol/l, haemoglobin A1c (HbA1C) ≥ 6.5% (48 mmol/mol) or physician-based diagnosis. RESULTS After a median 14.8 (range 12.5-16.8) years of follow-up, 110 incident diabetes cases occurred (15.6%). Participants with high FMI and LMI at baseline had higher composite incidence of type 2 diabetes (P < 0.001), and significantly increased risk of type 2 diabetes after adjustment for potential confounding factors (sex, physical activity, education and body mass index) compared to the other participants. CONCLUSION Contrary to a general belief greater muscle mass is not protective against type 2 diabetes. High LMI accompanied with high FMI seem to predict subsequent development of type 2 diabetes.
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14
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Lind L, Salihovic S, Risérus U, Kullberg J, Johansson L, Ahlström H, Eriksson JW, Oscarsson J. The Plasma Metabolomic Profile is Differently Associated with Liver Fat, Visceral Adipose Tissue, and Pancreatic Fat. J Clin Endocrinol Metab 2021; 106:e118-e129. [PMID: 33123723 PMCID: PMC7765636 DOI: 10.1210/clinem/dgaa693] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 08/21/2020] [Indexed: 12/16/2022]
Abstract
CONTEXT Metabolic differences between ectopic fat depots may provide novel insights to obesity-related diseases. OBJECTIVE To investigate the plasma metabolomic profiles in relation to visceral adipose tissue (VAT) volume and liver and pancreas fat percentages. DESIGN Cross-sectional. SETTING Multicenter at academic research laboratories. PATIENTS Magnetic resonance imaging (MRI) was used to assess VAT volume, the percentage of fat in the liver and pancreas (proton density fat fraction [PDFF]) at baseline in 310 individuals with a body mass index ≥ 25 kg/m2 and with serum triglycerides ≥ 1.7 mmol/l and/or type 2 diabetes screened for inclusion in the 2 effect of omega-3 carboxylic acid on liver fat content studies. INTERVENTION None. MAIN OUTCOME MEASURE Metabolomic profiling with mass spectroscopy enabled the determination of 1063 plasma metabolites. RESULTS Thirty metabolites were associated with VAT volume, 31 with liver PDFF, and 2 with pancreas PDFF when adjusting for age, sex, total body fat mass, and fasting glucose. Liver PDFF and VAT shared 4 metabolites, while the 2 metabolites related to pancreas PDFF were unique. The top metabolites associated with liver PDFF were palmitoyl-palmitoleoyl-GPC (16:0/16:1), dihydrosphingomyelin (d18:0/22:0), and betaine. The addition of these metabolites to the Liver Fat Score improved C-statistics significantly (from 0.776 to 0.861, P = 0.0004), regarding discrimination of liver steatosis. CONCLUSION Liver PDFF and VAT adipose tissue shared several metabolic associations, while those were not shared with pancreatic PDFF, indicating partly distinct metabolic profiles associated with different ectopic fat depots. The addition of 3 metabolites to the Liver Fat Score improved the prediction of liver steatosis.
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Affiliation(s)
- Lars Lind
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Correspondence and Reprint Requests: Lars Lind, MD, Professor, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
| | | | - Ulf Risérus
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden
| | - Joel Kullberg
- Antaros Medical AB, Gothenburg, Sweden
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
| | | | - Håkan Ahlström
- Antaros Medical AB, Gothenburg, Sweden
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
| | - Jan W Eriksson
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Jan Oscarsson
- BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
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15
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Ramírez-Vélez R, Ezzatvar Y, Izquierdo M, García-Hermoso A. Effect of exercise on myosteatosis in adults: a systematic review and meta-analysis. J Appl Physiol (1985) 2020; 130:245-255. [PMID: 33180646 DOI: 10.1152/japplphysiol.00738.2020] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Muscle tissue typically contains only small amounts of adipose tissue, and the excess deposition of adiposity is considered a pathological phenomenon termed myosteatosis. Several studies have assessed the effects of exercise alone on the severity of myosteatosis, and some studies have reported promising results. We performed a systematic review and meta-analysis to investigate the effects of exercise interventions on myosteatosis (i.e., lipid infiltration and muscle radiation attenuation). Studies were identified through a systematic search of three databases and limited to randomized controlled trials (RCTs) focused on evaluating the effect of exercise interventions on lipid infiltration and/or muscle attenuation in adults. Thirteen studies met the inclusion criteria, and 12 were included in the meta-analysis (n = 465, 84.7% women). The volume of lipid infiltration was decreased in the exercise group compared with the control group [Hedges' g = -0.45, 95% confidence interval (CI), -0.74 to -0.16; P = 0.008, I2 = 0%], and the degree of muscle radiation attenuation was increased (Hedges' g = 0.67, 95% CI, 0.22 to 1.13; P = 0.009, I2 = 59.3%). Based on meta-regression analyses, there were no significant effects of mean age at baseline (lipid infiltration, β = -0.008, 95% CI, -0.035 to 0.019; P = 0.495; muscle radiation attenuation, β = -0.013, 95% CI, -0.036 to 0.011; P = 0.248) and intervention duration (lipid infiltration, β = -0.008, 95% CI, -0.028 to 0.010; P = 0.311; muscle radiation attenuation, β = -0.018, 95% CI, -0.050 to 0.014; P = 0.230) on the effect size estimates. Overall, our findings indicate that exercise can significantly improve muscle quality in populations at risk of developing obesity and sarcopenia-related disability.NEW & NOTEWORTHY Muscle tissue typically contains only small amounts of adipose tissue, and the excess deposition of adiposity is considered a pathological phenomenon termed myosteatosis. The volume of lipid infiltration tissue was decreased in the exercise group compared with the control group, and muscle attenuation coefficient was increased. Based on the meta-regression analyses, the mean age at baseline and intervention duration did not affect the effect size estimates for lipid infiltration tissue and muscle radiation attenuation.
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Affiliation(s)
- Robinson Ramírez-Vélez
- Navarrabiomed, Universidad Pública de Navarra-Complejo Hospitalario de Navarra, Instituto de Investigación Sanitaria de Navarra, Pamplona, Spain
| | - Yasmin Ezzatvar
- Exercise Intervention for Health Research Group, Department of Physiotherapy, Universitat de València, Valencia, Spain
| | - Mikel Izquierdo
- Navarrabiomed, Universidad Pública de Navarra-Complejo Hospitalario de Navarra, Instituto de Investigación Sanitaria de Navarra, Pamplona, Spain.,Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable, Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio García-Hermoso
- Navarrabiomed, Universidad Pública de Navarra-Complejo Hospitalario de Navarra, Instituto de Investigación Sanitaria de Navarra, Pamplona, Spain.,Laboratorio de Ciencias de la Actividad Física, el Deporte y la Salud, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Santiago, Chile
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16
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Montalcini T, Pujia A, Donini LM, Frittitta L, Galvano F, Natali A, Pironi L, Porrini M, Riso P, Rivellese AA, Russo D, Scapagnini G, Serafini M, Tagliabue A, De Lorenzo A. A Call to Action: Now Is the Time to Screen Elderly and Treat Osteosarcopenia, a Position Paper of the Italian College of Academic Nutritionists MED/49 (ICAN-49). Nutrients 2020; 12:E2662. [PMID: 32878316 PMCID: PMC7550989 DOI: 10.3390/nu12092662] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/24/2020] [Accepted: 08/28/2020] [Indexed: 02/06/2023] Open
Abstract
Aging is a risk factor for the development of multiple chronic diseases, including cardiovascular disease, cancer and dementia. Life expectancy has increased in certain countries but this phenomenon is associated with a reduction of years of healthy life. Aging is associated with a number of physical and functional changes, especially sarcopenia. Sarcopenia is a clinical condition associated with a decrease in skeletal muscle and muscle strength, however, sarcopenia is a reversible condition. On the basis of the current scientific literature, sarcopenia could more appropriately capture an individual's vulnerability to negative health-related outcomes since it represents an early form of the chronic diseases. Recognition of this clinical condition can improve the management of older individuals in many different clinical settings. Despite the limitations of the indirect methods used to study body composition, the Italian College of the Academic Nutritionists ME/49 recommends that health authorities and health professionals around the world should make a greater effort to diagnose sarcopenia earlier and to manage it more effectively. In line with the development of cancer screening, the use of two diagnostic tools for sarcopenia (BIA and DXA) should be implemented.
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Affiliation(s)
- Tiziana Montalcini
- Department of Clinical and Experiment Medicine, University of Catanzaro Magna Grecia, Viale Europa, 88100 Catanzaro, Italy;
| | - Arturo Pujia
- Department of Clinical and Experiment Medicine, University of Catanzaro Magna Grecia, Viale Europa, 88100 Catanzaro, Italy;
| | - Lorenzo M. Donini
- Department of Experimental Medicine, University of la Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy;
| | - Lucia Frittitta
- Department of Clinical and Experiment Medicine, University of Catania, Via Santa Sofia, 86-95123 Catania, Italy;
| | - Fabio Galvano
- Department of Biomedical and Biotechnology Science, University of Catania, Via Santa Sofia, 86-95123 Catania, Italy;
| | - Andrea Natali
- Department of Clinical and Experiment Medicine, University of Pisa, Lungarno Antonio Pacinotti, 43, 56126 Pisa, Italy;
| | - Loris Pironi
- Department of Medical and Surgical Science, University of Bologna, Via Pupilli, 1, 40136 Bologna, Italy;
| | - Marisa Porrini
- Department of Food, Nutrition and Environment Science, University of Milan, Via Festa del Perdono, 7, 20122 Milano, Italy; (M.P.); (P.R.)
| | - Patrizia Riso
- Department of Food, Nutrition and Environment Science, University of Milan, Via Festa del Perdono, 7, 20122 Milano, Italy; (M.P.); (P.R.)
| | - Angela Albarosa Rivellese
- Department of Clinical and Experiment Medicine, University of Naples Federico II, Corso Umberto I, 40, 80138 Napoli, Italy;
| | - Diego Russo
- Department of Health Science, University of Catanzaro Magna Grecia, Viale Europa, 88100 Catanzaro, Italy;
| | - Giovanni Scapagnini
- Department of Medicine and Health Science, University of Molise, Via F. De Sanctis, 86100 Campobasso, Italy;
| | - Mauro Serafini
- Department of Bioscience and food technology, University of Teramo, Via Renato Balzarini, 1, 64100 Teramo, Italy;
| | - Anna Tagliabue
- Department of Public Health, University of Pavia, Corso Str. Nuova, 65, 27100 Pavia, Italy;
| | - Antonino De Lorenzo
- Biomedicine and Prevention, University of Tor Vergata, Via Montpellier, 1, 00133 Roma, Italy;
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17
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Kalyani RR, Metter EJ, Xue QL, Egan JM, Chia CW, Studenski S, Shaffer NC, Golden S, Al-Sofiani M, Florez H, Ferrucci L. The Relationship of Lean Body Mass With Aging to the Development of Diabetes. J Endocr Soc 2020; 4:bvaa043. [PMID: 32666006 PMCID: PMC7334003 DOI: 10.1210/jendso/bvaa043] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 04/16/2020] [Indexed: 12/22/2022] Open
Abstract
CONTEXT Older adults have the greatest burden of diabetes; however, the contribution of age-related muscle loss to its development remains unclear. OBJECTIVE We assessed the relationship of lean body mass with aging to incident diabetes in community-dwelling adults. DESIGN AND SETTING We studied participants in the Baltimore Longitudinal Study of Aging with median follow-up of 7 years (range 1-16). Cox proportional hazard models with age as the time scale were used. Time-dependent lean body mass measures were updated at each follow-up visit available. PARTICIPANTS Participants included 871 men and 984 women without diabetes who had ≥ 1 assessment of body composition using dual x-ray absorptiometry. MAIN OUTCOMES Incident diabetes, defined as self-reported history and use of glucose-lowering medications; or fasting plasma glucose ≥ 126 mg/dL and 2-hour oral glucose tolerance test glucose ≥ 200 mg/dL either at the same visit or 2 consecutive visits. RESULTS The baseline mean [standard deviation] age was 58.9 [17.3] years. Men and women with a higher percentage of total lean body mass had lower fasting and 2-hour glucose levels, and less prediabetes (all P < 0.01). Among men, comparing highest versus lowest quartiles, percentage of total lean body mass (hazard ratio [HR], 0.46; 95% confidence interval, 0.22-0.97), percentage leg lean mass (HR, 0.38; 0.15-0.96), and lean-to-fat mass ratio (HR, 0.39; 0.17-0.89) were inversely associated with incident diabetes after accounting for race and attenuated after adjustment for height and weight. Conversely, absolute total lean body mass was positively associated with incident diabetes among women, with similar trends in men. No associations were observed with muscle strength or quality. CONCLUSIONS Relatively lower lean body mass with aging is associated with incident diabetes in men and partially related to anthropometrics, but not so in women.
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Affiliation(s)
- Rita R Kalyani
- Division of Endocrinology, Diabetes & Metabolism, The Johns Hopkins University, Baltimore, Maryland
- Center on Aging and Health, The Johns Hopkins University, Baltimore, Maryland
| | - E Jeffrey Metter
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Qian-Li Xue
- Center on Aging and Health, The Johns Hopkins University, Baltimore, Maryland
- Division of Geriatrics, The Johns Hopkins University, Baltimore, Maryland
| | | | - Chee W Chia
- National Institute on Aging, Baltimore, Maryland
| | | | | | - Sherita Golden
- Division of Endocrinology, Diabetes & Metabolism, The Johns Hopkins University, Baltimore, Maryland
- The Welch Center for Prevention, Epidemiology and Clinical Research, The Johns Hopkins University, Baltimore, Maryland
| | - Mohammed Al-Sofiani
- Division of Endocrinology, Diabetes & Metabolism, The Johns Hopkins University, Baltimore, Maryland
- Division of Endocrinology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Hermes Florez
- Division of Geriatrics & Endocrinology, University of Miami Miller School of Medicine, Miami, Florida
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Cheikhi A, Anguiano T, Lasak J, Qian B, Sahu A, Mimiya H, Cohen CC, Wipf P, Ambrosio F, Barchowsky A. Arsenic Stimulates Myoblast Mitochondrial Epidermal Growth Factor Receptor to Impair Myogenesis. Toxicol Sci 2020; 176:162-174. [PMID: 32159786 PMCID: PMC7357174 DOI: 10.1093/toxsci/kfaa031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Arsenic exposure impairs muscle metabolism, maintenance, progenitor cell differentiation, and regeneration following acute injury. Low to moderate arsenic exposures target muscle fiber and progenitor cell mitochondria to epigenetically decrease muscle quality and regeneration. However, the mechanisms for how low levels of arsenic signal for prolonged mitochondrial dysfunction are not known. In this study, arsenic attenuated murine C2C12 myoblasts differentiation and resulted in abnormal undifferentiated myoblast proliferation. Arsenic prolonged ligand-independent phosphorylation of mitochondrially localized epidermal growth factor receptor (EGFR), a major driver of proliferation. Treating cells with a selective EGFR kinase inhibitor, AG-1478, prevented arsenic inhibition of myoblast differentiation. AG-1478 decreased arsenic-induced colocalization of pY845EGFR with mitochondrial cytochrome C oxidase subunit II, as well as arsenic-enhanced mitochondrial membrane potential, reactive oxygen species generation, and cell cycling. All of the arsenic effects on mitochondrial signaling and cell fate were mitigated or reversed by addition of mitochondrially targeted agents that restored mitochondrial integrity and function. Thus, arsenic-driven pathogenesis in skeletal muscle requires sustained mitochondrial EGFR activation that promotes progenitor cell cycling and proliferation at the detriment of proper differentiation. Collectively, these findings suggest that the arsenic-activated mitochondrial EGFR pathway drives pathogenic signaling for impaired myoblast metabolism and function.
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Affiliation(s)
- Amin Cheikhi
- Division of Geriatric Medicine, Department of Medicine
- Department of Environmental and Occupational Health
- Department of Physical Medicine and Rehabilitation
| | | | - Jane Lasak
- Department of Physical Medicine and Rehabilitation
| | - Baoli Qian
- Department of Environmental and Occupational Health
| | - Amrita Sahu
- Department of Physical Medicine and Rehabilitation
| | | | | | | | - Fabrisia Ambrosio
- Department of Environmental and Occupational Health
- Department of Physical Medicine and Rehabilitation
- McGowan Institute for Regenerative Medicine
- Department of Bioengineering
| | - Aaron Barchowsky
- Department of Environmental and Occupational Health
- Department of Bioengineering
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
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19
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Fibroblast Growth Factor 21 and the Adaptive Response to Nutritional Challenges. Int J Mol Sci 2019; 20:ijms20194692. [PMID: 31546675 PMCID: PMC6801670 DOI: 10.3390/ijms20194692] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 02/07/2023] Open
Abstract
The Fibroblast Growth Factor 21 (FGF21) is considered an attractive therapeutic target for obesity and obesity-related disorders due to its beneficial effects in lipid and carbohydrate metabolism. FGF21 response is essential under stressful conditions and its metabolic effects depend on the inducer factor or stress condition. FGF21 seems to be the key signal which communicates and coordinates the metabolic response to reverse different nutritional stresses and restores the metabolic homeostasis. This review is focused on describing individually the FGF21-dependent metabolic response activated by some of the most common nutritional challenges, the signal pathways triggering this response, and the impact of this response on global homeostasis. We consider that this is essential knowledge to identify the potential role of FGF21 in the onset and progression of some of the most prevalent metabolic pathologies and to understand the potential of FGF21 as a target for these diseases. After this review, we conclude that more research is needed to understand the mechanisms underlying the role of FGF21 in macronutrient preference and food intake behavior, but also in β-klotho regulation and the activity of the fibroblast activation protein (FAP) to uncover its therapeutic potential as a way to increase the FGF21 signaling.
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20
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Lyophilized Maqui ( Aristotelia chilensis) Berry Induces Browning in the Subcutaneous White Adipose Tissue and Ameliorates the Insulin Resistance in High Fat Diet-Induced Obese Mice. Antioxidants (Basel) 2019; 8:antiox8090360. [PMID: 31480627 PMCID: PMC6769892 DOI: 10.3390/antiox8090360] [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: 07/01/2019] [Revised: 08/22/2019] [Accepted: 08/23/2019] [Indexed: 12/15/2022] Open
Abstract
Maqui (Aristotelia Chilensis) berry features a unique profile of anthocyanidins that includes high amounts of delphinidin-3-O-sambubioside-5-O-glucoside and delphinidin-3-O-sambubioside and has shown positive effects on fasting glucose and insulin levels in humans and murine models of type 2 diabetes and obesity. The molecular mechanisms underlying the impact of maqui on the onset and development of the obese phenotype and insulin resistance was investigated in high fat diet-induced obese mice supplemented with a lyophilized maqui berry. Maqui-dietary supplemented animals showed better insulin response and decreased weight gain but also a differential expression of genes involved in de novo lipogenesis, fatty acid oxidation, multilocular lipid droplet formation and thermogenesis in subcutaneous white adipose tissue (scWAT). These changes correlated with an increased expression of the carbohydrate response element binding protein b (Chrebpb), the sterol regulatory binding protein 1c (Srebp1c) and Cellular repressor of adenovirus early region 1A-stimulated genes 1 (Creg1) and an improvement in the fibroblast growth factor 21 (FGF21) signaling. Our evidence suggests that maqui dietary supplementation activates the induction of fuel storage and thermogenesis characteristic of a brown-like phenotype in scWAT and counteracts the unhealthy metabolic impact of an HFD. This induction constitutes a putative strategy to prevent/treat diet-induced obesity and its associated comorbidities.
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Abstract
The combination of next generation sequencing (NGS) and automated liquid handling platforms has led to a revolution in single-cell genomic studies. However, many molecules that are critical to understanding the functional roles of cells in a complex tissue or organs, are not directly encoded in the genome, and therefore cannot be profiled with NGS. Lipids, for example, play a critical role in many metabolic processes but cannot be detected by sequencing. Recent developments in quantitative imaging, particularly coherent Raman scattering (CRS) techniques, have produced a suite of tools for studying lipid content in single cells. This article reviews CRS imaging and computational image processing techniques for non-destructive profiling of dynamic changes in lipid composition and spatial distribution at the single-cell level. As quantitative CRS imaging progresses synergistically with microfluidic and microscopic platforms for single-cell genomic analysis, we anticipate that these techniques will bring researchers closer towards combined lipidomic and genomic analysis.
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Affiliation(s)
- Anushka Gupta
- UC Berkeley-UC San Francisco Graduate Program in Bioengineering, University of California, Berkeley Graduate Division, Berkeley, California, USA.
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22
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Butruille L, Marousez L, Pourpe C, Oger F, Lecoutre S, Catheline D, Görs S, Metges CC, Guinez C, Laborie C, Deruelle P, Eeckhoute J, Breton C, Legrand P, Lesage J, Eberlé D. Maternal high-fat diet during suckling programs visceral adiposity and epigenetic regulation of adipose tissue stearoyl-CoA desaturase-1 in offspring. Int J Obes (Lond) 2019; 43:2381-2393. [PMID: 30622312 DOI: 10.1038/s41366-018-0310-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/15/2018] [Accepted: 12/10/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The lactation-suckling period is critical for white adipose tissue (WAT) development. Early postnatal nutrition influences later obesity risk but underlying mechanisms remain elusive. Here, we tested whether altered postnatal nutrition specifically during suckling impacts epigenetic regulation of key metabolic genes in WAT and alter long-term adiposity set point. METHODS We analyzed the effects of maternal high-fat (HF) feeding in rats exclusively during lactation-suckling on breast milk composition and its impact on male offspring visceral epidydimal (eWAT) and subcutaneous inguinal (iWAT) depots during suckling and in adulthood. RESULTS Maternal HF feeding during lactation had no effect on mothers' body weight (BW) or global breast milk composition, but induced qualitative changes in breast milk fatty acid (FA) composition (high n-6/n-3 polyunsaturated FA ratio and low medium-chain FA content). During suckling, HF neonates showed increased BW and mass of both eWAT and iWAT depot but only eWAT displayed an enhanced adipogenic transcriptional signature. In adulthood, HF offspring were predisposed to weight gain and showed increased hyperplastic growth only in eWAT. This specific eWAT expansion was associated with increased expression and activity of stearoyl-CoA desaturase-1 (SCD1), a key enzyme of FA metabolism. SCD1 converts saturated FAs, e.g. palmitate and stearate, to monounsaturated FAs, palmitoleate and oleate, which are the predominant substrates for triglyceride synthesis. Scd1 upregulation in eWAT was associated with reduced DNA methylation in Scd1 promoter surrounding a PPARγ-binding region. Conversely, changes in SCD1 levels and methylation were not observed in iWAT, coherent with a depot-specific programming. CONCLUSIONS Our data reveal that maternal HF feeding during suckling programs long-term eWAT expansion in part by SCD1 epigenetic reprogramming. This programming events occurred with drastic changes in breast milk FA composition, suggesting that dietary FAs are key metabolic programming factors in the early postnatal period.
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Affiliation(s)
- Laura Butruille
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Lucie Marousez
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Charlène Pourpe
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Frédérik Oger
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Simon Lecoutre
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Daniel Catheline
- Laboratoire de Biochimie et Nutrition Humaine INRA 1378, Agrocampus Ouest, 65 rue de Saint Brieuc, 35042, Rennes cedex, France
| | - Solvig Görs
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology, D-18196, Dummerstorf, Germany
| | - Cornelia C Metges
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology, D-18196, Dummerstorf, Germany
| | - Céline Guinez
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Christine Laborie
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Philippe Deruelle
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Jérôme Eeckhoute
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000, Lille, France
| | - Christophe Breton
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Philippe Legrand
- Laboratoire de Biochimie et Nutrition Humaine INRA 1378, Agrocampus Ouest, 65 rue de Saint Brieuc, 35042, Rennes cedex, France
| | - Jean Lesage
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France
| | - Delphine Eberlé
- Univ. Lille, EA4489, Équipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, F-59000, Lille, France.
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23
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Haberka M, Stolarz-Skrzypek K, Biedroń M, Szóstak-Janiak K, Partyka M, Olszanecka-Glinianowicz M, Gąsior Z. Obesity, Visceral Fat, and Hypertension-Related Complications. Metab Syndr Relat Disord 2018; 16:521-529. [PMID: 30183499 DOI: 10.1089/met.2018.0062] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background: Hypertension and obesity are very common and complex cardiovascular (CV) risk factors. Our aim was to provide a comprehensive assessment of associations between visceral fat depots and vascular or cardiac complications of hypertension. Methods: All the consecutive patients (age: 45-80 years old) scheduled for elective coronary angiography in the Department of Cardiology were screened, and 400 patients were included into the study group. All the patients had a comprehensive clinical assessment focused on hypertension and obesity, risk factors, fat depots, and several hypertension-related vascular or cardiac complications. Results: The study group (n = 400; F/M: 140/260; age: 61 ± 7 years) included patients with hypertension (n = 354; 88.5%) and normal blood pressure (n = 46; 11.5%) and individuals with obesity (n = 192; 48%), diabetes (n = 139; 35%), metabolic syndrome (n = 240; 60%), and coronary artery disease (n = 286; 71%). Patients with higher degrees of hypertension (grade 3 vs. 2 vs. 1) showed increased body mass index (BMI) and waist circumference and ultrasound indexes of perivascular, epicardial, and abdominal visceral fat with no differences in age, waist-hip ratio, and subcutaneous fat. Both visceral fat depots: perivascular fat (carotid extra-media thickness) and abdominal visceral fat (intra-abdominal thickness) assessed as single measures and ratios were significantly increased in hypertensive patients with high versus low global CV risk in a hypertension-focused risk model (differences more pronounced in patients ≤60 years old). Visceral fat parameters were not independent, but rather additive to general obesity (BMI), except for visceral abdominal fat depot. Conclusions: Visceral abdominal and perivascular fat depots assessed as ultrasound indexes are associated with complications of hypertension and CV risk indicators, especially in patients with a mild-to-moderate hypertension and in younger patients.
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Affiliation(s)
- Maciej Haberka
- Department of Cardiology, School of Health Sciences, Medical University of Silesia, Katowice, Poland
| | - Katarzyna Stolarz-Skrzypek
- First Department of Cardiology, Interventional Electrocardiology and Hypertension, Jagiellonian University Medical College, Cracow, Poland
| | - Małgorzata Biedroń
- Department of Cardiology, School of Health Sciences, Medical University of Silesia, Katowice, Poland
| | - Karolina Szóstak-Janiak
- Department of Cardiology, School of Health Sciences, Medical University of Silesia, Katowice, Poland
| | | | - Magdalena Olszanecka-Glinianowicz
- Health Promotion and Obesity Management Unit, Department of Pathophysiology, Medical School in Katowice, Medical University of Silesia, Katowice, Poland
| | - Zbigniew Gąsior
- Department of Cardiology, School of Health Sciences, Medical University of Silesia, Katowice, Poland
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24
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Agrawal M, Yeo CR, Shabbir A, Chhay V, Silver DL, Magkos F, Vidal-Puig A, Toh SA. Fat storage-inducing transmembrane protein 2 (FIT2) is less abundant in type 2 diabetes, and regulates triglyceride accumulation and insulin sensitivity in adipocytes. FASEB J 2018; 33:430-440. [PMID: 30020828 DOI: 10.1096/fj.201701321rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fat storage-inducing transmembrane protein 2 (FIT2) aids in partitioning of cellular triacylglycerol into lipid droplets. A genome-wide association study reported FITM2-R3H domain containing like-HNF4A locus to be associated with type 2 diabetes (T2DM) in East Asian populations. Mice with adipose tissue (AT)-specific FIT2 knockout exhibited lipodystrophic features, with reduced AT mass, insulin resistance, and greater inflammation in AT when fed a high-fat diet. The role of FIT2 in regulating human adipocyte function is not known. Here, we found FIT2 protein abundance is lower in subcutaneous and omental AT obtained from patients with T2DM compared with nondiabetic control subjects. Partial loss of FIT2 protein in primary human adipocytes attenuated their lipid storage capacity and induced insulin resistance. After palmitate treatment, triacylglycerol accumulation, insulin-induced Akt (Ser-473) phosphorylation, and insulin-stimulated glucose uptake were significantly reduced in FIT2 knockdown adipocytes compared with control cells. Gene expression of proinflammatory cytokines IL-18 and IL-6 and phosphorylation of the endoplasmic reticulum stress marker inositol-requiring enzyme 1α were greater in FIT2 knockdown adipocytes than in control cells. Our results show for the first time that FIT2 is associated with T2DM in humans and plays an integral role in maintaining metabolically healthy AT function.-Agrawal, M., Yeo, C. R., Shabbir, A., Chhay, V., Silver, D. L., Magkos, F., Vidal-Puig, A., Toh, S.-A. Fat storage-inducing transmembrane protein 2 (FIT2) is less abundant in type 2 diabetes, and regulates triglyceride accumulation and insulin sensitivity in adipocytes.
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Affiliation(s)
- Madhur Agrawal
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Chia Rou Yeo
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Asim Shabbir
- Department of Surgery, National University Hospital, Singapore
| | - Vanna Chhay
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - David L Silver
- Signature Research Program in Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School, Singapore
| | - Faidon Magkos
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Singapore Institute of Clinical Sciences (SICS), Agency for Science, Technology, and Research (A*STAR), Singapore
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom.,Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Sue-Anne Toh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Department of Medicine, National University Health System, Singapore
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25
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The histone demethylase Phf2 acts as a molecular checkpoint to prevent NAFLD progression during obesity. Nat Commun 2018; 9:2092. [PMID: 29844386 PMCID: PMC5974278 DOI: 10.1038/s41467-018-04361-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 04/23/2018] [Indexed: 01/01/2023] Open
Abstract
Aberrant histone methylation profile is reported to correlate with the development and progression of NAFLD during obesity. However, the identification of specific epigenetic modifiers involved in this process remains poorly understood. Here, we identify the histone demethylase Plant Homeodomain Finger 2 (Phf2) as a new transcriptional co-activator of the transcription factor Carbohydrate Responsive Element Binding Protein (ChREBP). By specifically erasing H3K9me2 methyl-marks on the promoter of ChREBP-regulated genes, Phf2 facilitates incorporation of metabolic precursors into mono-unsaturated fatty acids, leading to hepatosteatosis development in the absence of inflammation and insulin resistance. Moreover, the Phf2-mediated activation of the transcription factor NF-E2-related factor 2 (Nrf2) further reroutes glucose fluxes toward the pentose phosphate pathway and glutathione biosynthesis, protecting the liver from oxidative stress and fibrogenesis in response to diet-induced obesity. Overall, our findings establish a downstream epigenetic checkpoint, whereby Phf2, through facilitating H3K9me2 demethylation at specific gene promoters, protects liver from the pathogenesis progression of NAFLD.
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26
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Kotzbeck P, Giordano A, Mondini E, Murano I, Severi I, Venema W, Cecchini MP, Kershaw EE, Barbatelli G, Haemmerle G, Zechner R, Cinti S. Brown adipose tissue whitening leads to brown adipocyte death and adipose tissue inflammation. J Lipid Res 2018; 59:784-794. [PMID: 29599420 DOI: 10.1194/jlr.m079665] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 02/20/2018] [Indexed: 12/11/2022] Open
Abstract
In mammals, white adipose tissue (WAT) stores and releases lipids, whereas brown adipose tissue (BAT) oxidizes lipids to fuel thermogenesis. In obese individuals, WAT undergoes profound changes; it expands, becomes dysfunctional, and develops a low-grade inflammatory state. Importantly, BAT content and activity decline in obese subjects, mainly as a result of the conversion of brown adipocytes to white-like unilocular cells. Here, we show that BAT "whitening" is induced by multiple factors, including high ambient temperature, leptin receptor deficiency, β-adrenergic signaling impairment, and lipase deficiency, each of which is capable of inducing macrophage infiltration, brown adipocyte death, and crown-like structure (CLS) formation. Brown-to-white conversion and increased CLS formation were most marked in BAT from adipose triglyceride lipase (Atgl)-deficient mice, where, according to transmission electron microscopy, whitened brown adipocytes contained enlarged endoplasmic reticulum, cholesterol crystals, and some degenerating mitochondria, and were surrounded by an increased number of collagen fibrils. Gene expression analysis showed that BAT whitening in Atgl-deficient mice was associated to a strong inflammatory response and NLRP3 inflammasome activation. Altogether, the present findings suggest that converted enlarged brown adipocytes are highly prone to death, which, by promoting inflammation in whitened BAT, may contribute to the typical inflammatory state seen in obesity.
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Affiliation(s)
- Petra Kotzbeck
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Antonio Giordano
- Department of Experimental and Clinical Medicine and Center of Obesity, University of Ancona (Politecnica delle Marche)-United Hospitals, Ancona, Italy
| | - Eleonora Mondini
- Department of Experimental and Clinical Medicine and Center of Obesity, University of Ancona (Politecnica delle Marche)-United Hospitals, Ancona, Italy
| | - Incoronata Murano
- Department of Experimental and Clinical Medicine and Center of Obesity, University of Ancona (Politecnica delle Marche)-United Hospitals, Ancona, Italy
| | - Ilenia Severi
- Department of Experimental and Clinical Medicine and Center of Obesity, University of Ancona (Politecnica delle Marche)-United Hospitals, Ancona, Italy
| | - Wiebe Venema
- Department of Experimental and Clinical Medicine and Center of Obesity, University of Ancona (Politecnica delle Marche)-United Hospitals, Ancona, Italy
| | - Maria Paola Cecchini
- Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, Italy
| | - Erin E Kershaw
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Giorgio Barbatelli
- Department of Experimental and Clinical Medicine and Center of Obesity, University of Ancona (Politecnica delle Marche)-United Hospitals, Ancona, Italy
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Saverio Cinti
- Department of Experimental and Clinical Medicine and Center of Obesity, University of Ancona (Politecnica delle Marche)-United Hospitals, Ancona, Italy
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27
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Guglielmi V, Sbraccia P. Obesity phenotypes: depot-differences in adipose tissue and their clinical implications. Eat Weight Disord 2018; 23:3-14. [PMID: 29230714 DOI: 10.1007/s40519-017-0467-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 11/29/2017] [Indexed: 12/17/2022] Open
Abstract
Obesity, defined as excess fat mass, increases risks for multiple chronic diseases, such as type 2 diabetes, cardiovascular disease, and several types of cancer. Beyond adiposity per se, the pattern of fat distribution, android or truncal as compared to gynoid or peripheral, has a profound influence on systemic metabolism and hence risk for obesity complications. Not only factors as genetics, environment, gender, and age account for the apparent compartmentalization of white adipose tissue (WAT) in the body. Indeed, the heterogeneity among different anatomical depots also appears to stem from their intrinsic diversity, including cellular developmental origin, proliferative capacity, glucose and lipid metabolism, insulin sensitivity, cytokine pattern, thermogenic ability, and vascularization. Under the obese condition, these depot-specific differences translate into specific WAT distribution patterns, giving rise to different cardiometabolic consequences. This review summarizes the clinical and mechanistic evidence for the depot-specific differences and the phenotypic characteristics of different WAT depots that link their depot-specific biology to obesity-specific complications.
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Affiliation(s)
- Valeria Guglielmi
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133, Rome, Italy.
- Internal Medicine Unit and Obesity Center, University Hospital Policlinico Tor Vergata, Rome, Italy.
| | - Paolo Sbraccia
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
- Internal Medicine Unit and Obesity Center, University Hospital Policlinico Tor Vergata, Rome, Italy
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28
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Interplay between Obesity-Induced Inflammation and cGMP Signaling in White Adipose Tissue. Cell Rep 2017; 18:225-236. [PMID: 28052251 DOI: 10.1016/j.celrep.2016.12.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 11/15/2016] [Accepted: 12/08/2016] [Indexed: 11/21/2022] Open
Abstract
Current worldwide figures suggest that obesity is pandemic. Understanding the underlying molecular mechanisms would help develop viable anti-obesity therapies. Here, we assess the influence of obesity-induced inflammation on white adipocyte cyclic guanosine monophosphate (cGMP) signaling, which is beneficial for adipocyte differentiation and thermogenesis. We find that murine gonadal and not inguinal fat is prone to obesity-induced inflammation. Correspondingly, the cGMP cascade is dysregulated in gonadal but not in inguinal fat of obese mice. Analysis of two independent human cohorts reveals a defective cGMP pathway only in visceral fat of obese subjects. Congruently, cGMP signaling is dysregulated in tumor necrosis factor α (TNF-α)-treated primary white adipocytes. TNF-α-mediated suppression of sGCβ1 is mediated via NF-κB, whereas PKG is repressed by JNK signaling. Additionally, TNF-α-activated JNK signaling suppresses PPARγ and aP2. Taken together, the intensity of obesity-induced inflammation dictates the amplitude of cGMP signaling dysregulation in white adipocytes through distinct pathways.
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29
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Adipose Tissue Function and Expandability as Determinants of Lipotoxicity and the Metabolic Syndrome. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 960:161-196. [PMID: 28585199 DOI: 10.1007/978-3-319-48382-5_7] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The adipose tissue organ is organised as distinct anatomical depots located all along the body axis and it is constituted of three different types of adipocytes : white, beige and brown which are integrated with vascular, immune, neural and extracellular stroma cells. These distinct adipocytes serve different specialised functions. The main function of white adipocytes is to ensure healthy storage of excess nutrients/energy and its rapid mobilisation to supply the demand of energy imposed by physiological cues in other organs, whereas brown and beige adipocytes are designed for heat production through uncoupling lipid oxidation from energy production. The concert action of the three type of adipocytes/tissues has been reported to ensure an optimal metabolic status in rodents. However, when one or multiple of these adipose depots become dysfunctional as a consequence of sustained lipid/nutrient overload, then insulin resistance and associated metabolic complications ensue. These metabolic alterations negatively affects the adipose tissue functionality and compromises global metabolic homeostasis. Optimising white adipose tissue expandability and its functional metabolic flexibility and/or promoting brown/beige mediated thermogenic activity counteracts obesity and its associated lipotoxic metabolic effects. The development of these therapeutic approaches requires a deep understanding of adipose tissue in all broad aspects. In this chapter we will discuss the characteristics of the different adipose tissue depots with respect to origins and precursors recruitment, plasticity, cellular composition and expandability capacity as well as molecular and metabolic signatures in both physiological and pathophysiological conditions.
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30
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Metabolic dysfunction following weight cycling in male mice. Int J Obes (Lond) 2016; 41:402-411. [PMID: 27840414 PMCID: PMC5344184 DOI: 10.1038/ijo.2016.193] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/30/2016] [Accepted: 09/23/2016] [Indexed: 12/15/2022]
Abstract
Background Combatting over-weight or obesity can lead to large fluctuations in an individual’s body weight, often referred to as weight cycling or “yo-yo” dieting. Current evidence regarding the potentially damaging effects of these changes is conflicting. Methods Here, we assess the metabolic effects of weight cycling in a murine model, comprising three dietary switches to normal or high fat diets at 6 week intervals; male C57BL/6 mice were fed either a control (C) or high fat (F) diet for 6 weeks (n=140/group). C and F groups were then either maintained on their initial diet (CC and FF respectively) or switched to a high fat (CF) or control (FC) diet (n=35/group). For the final 6 week interval, CC and CF groups were returned to the control diet (CCC and CFC groups) while FC and FF groups were placed on a high fat diet (FCF and FFF) (n=28/group). Results For the majority of metabolic outcomes changes aligned with dietary switches; however assessment of neuropeptides and receptors involved in appetite regulation and reward signalling pathways reveal variable patterns of expression. Furthermore, we demonstrate that multiple cycling events leads to a significant increase in internal fat deposition, even when compared to animals maintained on a high fat diet (Internal Fat: FCF: 7.4 ± 0.2g vs. FFF: 5.6 ± 0.2g; p<0.01). Conclusions Increased internal adipose tissue is strongly linked to the development of metabolic syndrome associated conditions such as type 2 diabetes, cardiovascular disease and hypertension. While further work will be required to elucidate the mechanisms underlying the neuronal control of energy homeostasis, these studies provide a causative link between weight cycling and adverse health.
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31
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Miljkovic I, Kuipers AL, Cvejkus R, Bunker CH, Patrick AL, Gordon CL, Zmuda JM. Myosteatosis increases with aging and is associated with incident diabetes in African ancestry men. Obesity (Silver Spring) 2016; 24:476-82. [PMID: 26694517 PMCID: PMC4731257 DOI: 10.1002/oby.21328] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 08/12/2015] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Skeletal muscle fat infiltration (known as myosteatosis) is greater in African compared with European ancestry men and may play an important role in the development of type 2 diabetes (T2D). However, prospective studies examining the magnitude of changes in myosteatosis with aging and their metabolic consequences are sparse. METHODS Longitudinal changes in peripheral quantitative computed tomography measured calf myosteatosis [intermuscular fat (mm(2) ) and skeletal muscle density as a measure of intramuscular fat (mg/cm(3) )] were examined in 1515 Afro-Caribbean men aged 40+ years recruited without regard to their health status. RESULTS During an average of 6.2 years of follow-up, an age-related increase in intermuscular fat and a decrease in skeletal muscle density were observed (all P < 0.0001), which remained significant in those who lost weight, gained weight, or remained weight stable (all P < 0.0001). In addition, muscle density loss accelerated with increasing age (P < 0.0001). Increased intermuscular fat during follow-up was associated with an increased incident risk of T2D independent of factors known to be associated with T2D (odds ratios per 1-SD increase in intermuscular fat = 1.29; 95% CI = 1.08-1.53). CONCLUSIONS Our findings suggest that both inter- and intramuscular fat increase with advancing age and that intermuscular fat contributes to development of T2D among African ancestry men.
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Affiliation(s)
- Iva Miljkovic
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Allison L Kuipers
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ryan Cvejkus
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Clareann H Bunker
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alan L Patrick
- Tobago Health Studies Office, Scarborough, Tobago, Trinidad and Tobago, West Indies
| | | | - Joseph M Zmuda
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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32
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Martínez-García C, Izquierdo-Lahuerta A, Vivas Y, Velasco I, Yeo TK, Chen S, Medina-Gomez G. Renal Lipotoxicity-Associated Inflammation and Insulin Resistance Affects Actin Cytoskeleton Organization in Podocytes. PLoS One 2015; 10:e0142291. [PMID: 26545114 PMCID: PMC4636358 DOI: 10.1371/journal.pone.0142291] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/19/2015] [Indexed: 01/01/2023] Open
Abstract
In the last few decades a change in lifestyle has led to an alarming increase in the prevalence of obesity and obesity-associated complications. Obese patients are at increased risk of developing hypertension, heart disease, insulin resistance (IR), dyslipidemia, type 2 diabetes and renal disease. The excess calories are stored as triglycerides in adipose tissue, but also may accumulate ectopically in other organs, including the kidney, which contributes to the damage through a toxic process named lipotoxicity. Recently, the evidence suggests that renal lipid accumulation leads to glomerular damage and, more specifically, produces dysfunction in podocytes, key cells that compose and maintain the glomerular filtration barrier. Our aim was to analyze the early mechanisms underlying the development of renal disease associated with the process of lipotoxicity in podocytes. Our results show that treatment of podocytes with palmitic acid produced intracellular accumulation of lipid droplets and abnormal glucose and lipid metabolism. This was accompanied by the development of inflammation, oxidative stress and endoplasmic reticulum stress and insulin resistance. We found specific rearrangements of the actin cytoskeleton and slit diaphragm proteins (Nephrin, P-Cadherin, Vimentin) associated with this insulin resistance in palmitic-treated podocytes. We conclude that lipotoxicity accelerates glomerular disease through lipid accumulation and inflammation. Moreover, saturated fatty acids specifically promote insulin resistance by disturbing the cytoarchitecture of podocytes. These data suggest that renal lipid metabolism and cytoskeleton rearrangements may serve as a target for specific therapies aimed at slowing the progression of podocyte failure during metabolic syndrome.
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Affiliation(s)
- Cristina Martínez-García
- Departamento de Ciencias Básicas de la Salud, Área de Bioquímica y Genética Molecular. Universidad Rey Juan Carlos, Avda. de Atenas s/n, Alcorcón, Madrid, Spain
| | - Adriana Izquierdo-Lahuerta
- Departamento de Ciencias Básicas de la Salud, Área de Bioquímica y Genética Molecular. Universidad Rey Juan Carlos, Avda. de Atenas s/n, Alcorcón, Madrid, Spain
| | - Yurena Vivas
- Departamento de Ciencias Básicas de la Salud, Área de Bioquímica y Genética Molecular. Universidad Rey Juan Carlos, Avda. de Atenas s/n, Alcorcón, Madrid, Spain
| | - Ismael Velasco
- Departamento de Ciencias Básicas de la Salud, Área de Bioquímica y Genética Molecular. Universidad Rey Juan Carlos, Avda. de Atenas s/n, Alcorcón, Madrid, Spain
| | - Tet-Kin Yeo
- Division of Nephrology/Hypertension, Northwestern University, Chicago, Illinois, United States of America
| | - Sheldon Chen
- Division of Nephrology/Hypertension, Northwestern University, Chicago, Illinois, United States of America
| | - Gema Medina-Gomez
- Departamento de Ciencias Básicas de la Salud, Área de Bioquímica y Genética Molecular. Universidad Rey Juan Carlos, Avda. de Atenas s/n, Alcorcón, Madrid, Spain
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Miljkovic I, Kuipers AL, Cauley JA, Prasad T, Lee CG, Ensrud KE, Cawthon PM, Hoffman AR, Dam TT, Gordon CL, Zmuda JM. Greater Skeletal Muscle Fat Infiltration Is Associated With Higher All-Cause and Cardiovascular Mortality in Older Men. J Gerontol A Biol Sci Med Sci 2015; 70:1133-40. [PMID: 25838547 DOI: 10.1093/gerona/glv027] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Skeletal muscle fat infiltration (myosteatosis) increases with aging, and has been associated with poor metabolic and musculoskeletal health, independent of overall adiposity. Studies examining the relationship of myosteatosis and mortality among older individuals recruited without regard to their health status are sparse. METHODS We evaluated the association of peripheral computed tomography measured calf myosteatosis (intermuscular fat and muscle density as a measure of intramuscular fat) with mortality in 1,063 community-dwelling older men. Cox proportional hazards models were used to estimate the risk of mortality independent of potential confounders. RESULTS During a mean follow-up of 7.2 years, 317 participants died. After adjustment for potential covariates and additional adjustment for whole body fat, lower skeletal muscle density was associated with increased all-cause mortality and cardiovascular disease mortality (hazard ratio [95% confidence interval] per standard deviation lower skeletal muscle density: 1.24 [1.09-1.41] and 1.46 [1.15-1.86], respectively), and to some extent with noncardiovascular disease mortality (1.18 [1.0-1.38], p = .053). After adjusting for trunk fat in a separate multivariable model, the association between skeletal muscle density and all-cause and cardiovascular disease mortality remained significant (both p < .01), while its association with noncardiovascular disease mortality became of borderline significance (p = .085). No other measures of adiposity, including calf intermuscular fat, were associated with mortality. CONCLUSION Our study reveals an independent association between skeletal muscle density and mortality in a community-based sample of older, predominantly Caucasian men. Further studies are needed to establish if this association is independent of other ectopic fat depots, and to identify the biological mechanisms underlying this relationship.
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Affiliation(s)
- Iva Miljkovic
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania.
| | - Allison L Kuipers
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania
| | - Jane A Cauley
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania
| | - Tanushree Prasad
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania
| | - Christine G Lee
- Research Service, Veterans Affairs Medical Center, Portland, Oregon
| | - Kristine E Ensrud
- Center for Chronic Disease Outcomes Research, Veterans Affairs Medical Center, Minneapolis, Minneapolis
| | | | - Andrew R Hoffman
- Stanford Prevention Research Center, Department of Medicine, School of Medicine, Stanford University, Palo Alto, CA
| | - Thuy-Tien Dam
- Department of Medicine, Columbia University, New York, New York
| | | | - Joseph M Zmuda
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania
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Barbarroja N, Rodriguez-Cuenca S, Nygren H, Camargo A, Pirraco A, Relat J, Cuadrado I, Pellegrinelli V, Medina-Gomez G, Lopez-Pedrera C, Tinahones FJ, Symons JD, Summers SA, Oresic M, Vidal-Puig A. Increased dihydroceramide/ceramide ratio mediated by defective expression of degs1 impairs adipocyte differentiation and function. Diabetes 2015; 64:1180-92. [PMID: 25352638 PMCID: PMC9757540 DOI: 10.2337/db14-0359] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Adipose tissue dysfunction is an important determinant of obesity-associated, lipid-induced metabolic complications. Ceramides are well-known mediators of lipid-induced insulin resistance in peripheral organs such as muscle. DEGS1 is the desaturase catalyzing the last step in the main ceramide biosynthetic pathway. Functional suppression of DEGS1 activity results in substantial changes in ceramide species likely to affect fundamental biological functions such as oxidative stress, cell survival, and proliferation. Here, we show that degs1 expression is specifically decreased in the adipose tissue of obese patients and murine models of genetic and nutritional obesity. Moreover, loss-of-function experiments using pharmacological or genetic ablation of DEGS1 in preadipocytes prevented adipogenesis and decreased lipid accumulation. This was associated with elevated oxidative stress, cellular death, and blockage of the cell cycle. These effects were coupled with increased dihydroceramide content. Finally, we validated in vivo that pharmacological inhibition of DEGS1 impairs adipocyte differentiation. These data identify DEGS1 as a new potential target to restore adipose tissue function and prevent obesity-associated metabolic disturbances.
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Affiliation(s)
- Nuria Barbarroja
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K. Instituto Maimónides de Investigación Biomédica de Córdoba, Reina Sofia University Hospital, Córdoba, Spain
| | - Sergio Rodriguez-Cuenca
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K.
| | - Heli Nygren
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Antonio Camargo
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K. Lipids and Atherosclerosis Research Unit, Instituto Maimónides de Investigación Biomédica de Córdoba, Reina Sofia University Hospital, Córdoba, Spain
| | - Ana Pirraco
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K. Department of Biochemistry (U38-FCT), Faculty of Medicine, University of Porto, Porto, Portugal
| | - Joana Relat
- Departament de Bioquímica i Biologia Molecular, Universitat de Barcelona, Barcelona, Spain
| | - Irene Cuadrado
- Departamento de Farmacología, Universidad Complutense de Madrid, Madrid, Spain
| | - Vanessa Pellegrinelli
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K
| | - Gema Medina-Gomez
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K
| | - Chary Lopez-Pedrera
- Instituto Maimónides de Investigación Biomédica de Córdoba, Reina Sofia University Hospital, Córdoba, Spain
| | - Francisco J Tinahones
- CIBER in Physiopathology of Obesity and Nutrition (CB06/03), Instituto de Salud Carlos III, Madrid, Spain Instituto de Investigación Biomédica de Málaga/Hospital Virgen de la Victoria, Malaga, Spain
| | - J David Symons
- College of Health, University of Utah, Salt Lake City, UT Division of Endocrinology, Metabolism, and Diabetes, University of Utah, Salt Lake City, UT
| | - Scott A Summers
- Program in Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore
| | - Matej Oresic
- VTT Technical Research Centre of Finland, Espoo, Finland Steno Diabetes Center, Gentofte, Denmark
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K. Wellcome Trust Sanger Institute, Hinxton, U.K.
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Delint-Ramirez I, Maldonado Ruiz R, Torre-Villalvazo I, Fuentes-Mera L, Garza Ocañas L, Tovar A, Camacho A. Genetic obesity alters recruitment of TANK-binding kinase 1 and AKT into hypothalamic lipid rafts domains. Neurochem Int 2015; 80:23-32. [DOI: 10.1016/j.neuint.2014.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 10/31/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022]
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Mori MA, Thomou T, Boucher J, Lee KY, Lallukka S, Kim JK, Torriani M, Yki-Järvinen H, Grinspoon SK, Cypess AM, Kahn CR. Altered miRNA processing disrupts brown/white adipocyte determination and associates with lipodystrophy. J Clin Invest 2014; 124:3339-51. [PMID: 24983316 DOI: 10.1172/jci73468] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 05/22/2014] [Indexed: 12/17/2022] Open
Abstract
miRNAs are important regulators of biological processes in many tissues, including the differentiation and function of brown and white adipocytes. The endoribonuclease dicer is a major component of the miRNA-processing pathway, and in adipose tissue, levels of dicer have been shown to decrease with age, increase with caloric restriction, and influence stress resistance. Here, we demonstrated that mice with a fat-specific KO of dicer develop a form of lipodystrophy that is characterized by loss of intra-abdominal and subcutaneous white fat, severe insulin resistance, and enlargement and "whitening" of interscapular brown fat. Additionally, KO of dicer in cultured brown preadipocytes promoted a white adipocyte-like phenotype and reduced expression of several miRNAs. Brown preadipocyte whitening was partially reversed by expression of miR-365, a miRNA known to promote brown fat differentiation; however, introduction of other miRNAs, including miR-346 and miR-362, also contributed to reversal of the loss of the dicer phenotype. Interestingly, fat samples from patients with HIV-related lipodystrophy exhibited a substantial downregulation of dicer mRNA expression. Together, these findings indicate the importance of miRNA processing in white and brown adipose tissue determination and provide a potential link between this process and HIV-related lipodystrophy.
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37
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Crescenzo R, Bianco F, Coppola P, Mazzoli A, Tussellino M, Carotenuto R, Liverini G, Iossa S. Fructose supplementation worsens the deleterious effects of short-term high-fat feeding on hepatic steatosis and lipid metabolism in adult rats. Exp Physiol 2014; 99:1203-13. [PMID: 24972835 DOI: 10.1113/expphysiol.2014.079632] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The purpose of the present study was to examine the short-term effect of high-fat or high-fat-high-fructose feeding on hepatic lipid metabolism and mitochondrial function in adult sedentary rats. Adult male rats were fed a high-fat or high-fat-high-fructose diet for 2 weeks. Body and liver composition, hepatic steatosis, plasma lipid profile and hepatic insulin sensitivity, together with whole-body and hepatic de novo lipogenesis, were assessed. Hepatic mitochondrial mass, functionality, oxidative stress and antioxidant defense were also measured. Rats fed the high-fat-high-fructose diet exhibited significantly higher plasma triglycerides, non-esterified fatty acids, insulin and indexes of hepatic insulin resistance compared with rats fed a low-fat or a high-fat diet. Hepatic triglycerides and ceramide, as well as the degree of steatosis and necrosis, were significantly higher, while liver p-Akt was significantly lower, in rats fed high-fat-high-fructose diet than in rats fed high-fat diet. A significant increase in non-protein respiratory quotient and hepatic fatty acid synthase and stearoyl CoA desaturase activity was found in rats fed the high-fat-high-fructose diet compared with those fed the high-fat diet. Significantly lower mitochondrial oxidative capacity but significantly higher oxidative stress was found in rats fed high-fat and high-fat-high-fructose diets compared with rats fed low-fat diet, while mitochondrial mass significantly increased only in rats fed high-fat-high-fructose diet. In conclusion, short-term consumption of a Western diet, rich in saturated fats and fructose, is more conducive to the development of liver steatosis and deleterious to glucose homeostasis than a high-fat diet.
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Ishikawa K, Yokote K. [Cutting-edge of medicine; dysfunction of adipose tissue and insulin resistance]. ACTA ACUST UNITED AC 2013; 102:2691-8. [PMID: 24400553 DOI: 10.2169/naika.102.2691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ko Ishikawa
- Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
| | - Koutaro Yokote
- Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
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Development of small-molecule inhibitors targeting adipose triglyceride lipase. Nat Chem Biol 2013; 9:785-7. [PMID: 24096302 PMCID: PMC3829776 DOI: 10.1038/nchembio.1359] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 08/29/2013] [Indexed: 01/03/2023]
Abstract
Adipose triglyceride lipase (ATGL) is rate limiting in the mobilization of fatty acids from cellular triglyceride stores. This central role in lipolysis marks ATGL as an interesting pharmacological target as deregulated fatty acid metabolism is closely linked to dyslipidemic and metabolic disorders. Here we report on the development and characterization of a small-molecule inhibitor of ATGL. Atglistatin is selective for ATGL and reduces fatty acid mobilization in vitro and in vivo.
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40
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Karastergiou K, Fried SK. Multiple adipose depots increase cardiovascular risk via local and systemic effects. Curr Atheroscler Rep 2013; 15:361. [PMID: 23982264 PMCID: PMC3997174 DOI: 10.1007/s11883-013-0361-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adipose tissue modifies the development of cardiovascular disease in a complex manner: obesity is a major risk factor, especially when accompanied by a central fat distribution. For that reason the characteristics of visceral adipose tissue have attracted most of the research interest thus far, and measurement of waist circumference is now recommended for everyday clinical practice. However, the direct, causative role of visceral fat in cardiometabolic disease remains to be established. Epidemiological and clinical studies show that accumulation of fat subcutaneously, in the gluteofemoral area, is protective against cardiovascular disease, but the exact molecular mechanisms remain unclear. In the last few years, imaging has allowed the study of smaller fat depots that may interact locally with important tissues: epicardial fat with the myocardium, perivascular fat with the vessel wall and the developing atherosclerotic plaque, and renal sinus fat with the renal artery. Unraveling the heterogeneous fat distribution and metabolic phenotypes in human obesity will facilitate optimal assessment of cardiovascular risk in overweight and obese individuals.
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Affiliation(s)
- Kalypso Karastergiou
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University, School of Medicine, 650 Albany St., EBRC-810, Boston, MA 02118, United States. Tel.: +1 617 638 7123; fax: +1 617 638 7124;
| | - Susan K. Fried
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University, School of Medicine, 650 Albany St., EBRC-810, Boston, MA 02118, United States
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41
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Maki S, Kadokawa H. Increased ectopic fat cells in the longitudinal muscularis layer of the oviduct isthmus in obese Japanese Black cows. Anim Sci J 2013; 85:207-12. [PMID: 23981058 DOI: 10.1111/asj.12110] [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: 01/28/2013] [Accepted: 06/06/2013] [Indexed: 11/29/2022]
Abstract
In obese humans, mesenchymal stem cells differentiate to become ectopic fat cells in muscles. These ectopic fat cells inhibit the contraction of vascular smooth muscles. Stem cells have been recently identified in the human oviduct, a structure important in reproduction. We therefore investigated the number of Oil Red O (ORO)-positive cells in the oviducts of control Japanese Black cows (n = 6; body condition score [BCS], 3.0 on a 5-point scale) compared to those with diet-induced obesity (n = 5; BCS, 4.0). We stained the ampulla and isthmus collected on the second day after ovulation with ORO and then counted the positive cells in each layer in 10 cross-sections of the ampulla or isthmus. The obese group (23.4 ± 3.4 in the 10 sections) had larger numbers of ORO-positive cells in the longitudinal muscularis of the isthmus (P < 0.05) than did the control group (15.0 ± 2.4). ORO-positive cells were also observed in all other layers of the isthmus and ampulla; however, the number of cells in these layers did not differ significantly between obese cows and controls. Whether this observed increase in ORO-positive cells in the oviducts of obese cows affects their reproduction warrants further study.
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Affiliation(s)
- Sachiko Maki
- Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
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42
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Beiroa D, Romero-Picó A, Langa C, Bernabeu C, López M, López-Novoa JM, Nogueiras R, Diéguez C. Heterozygous deficiency of endoglin decreases insulin and hepatic triglyceride levels during high fat diet. PLoS One 2013; 8:e54591. [PMID: 23336009 PMCID: PMC3545959 DOI: 10.1371/journal.pone.0054591] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 12/14/2012] [Indexed: 12/30/2022] Open
Abstract
Endoglin is a transmembrane auxiliary receptor for transforming growth factor-beta (TGF-beta) that is predominantly expressed on proliferating endothelial cells. It plays a wide range of physiological roles but its importance on energy balance or insulin sensitivity has been unexplored. Endoglin deficient mice die during midgestation due to cardiovascular defects. Here we report for first time that heterozygous endoglin deficiency in mice decreases high fat diet-induced hepatic triglyceride content and insulin levels. Importantly, these effects are independent of changes in body weight or adiposity. At molecular level, we failed to detect relevant changes in the insulin signalling pathway at basal levels in liver, muscle or adipose tissues that could explain the insulin-dependent effect. However, we found decreased triglyceride content in the liver of endoglin heterozygous mice fed a high fat diet in comparison to their wild type littermates. Overall, our findings indicate that endoglin is a potentially important physiological mediator of insulin levels and hepatic lipid metabolism.
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Affiliation(s)
- Daniel Beiroa
- Department of Physiology, School of Medicine-CIMUS – Instituto de Investigaciones Sanitarias (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Amparo Romero-Picó
- Department of Physiology, School of Medicine-CIMUS – Instituto de Investigaciones Sanitarias (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Carmen Langa
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Carmelo Bernabeu
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Miguel López
- Department of Physiology, School of Medicine-CIMUS – Instituto de Investigaciones Sanitarias (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - José M. López-Novoa
- Renal and Cardiovascular Physiopathology Unit, Department of Physiology and Pharmacology, University of Salamanca and Instituto de Investigaciones Biomédicas de Salamanca (IBSAL), Campus Miguel de Unamuno, Salamanca, Spain
| | - Ruben Nogueiras
- Department of Physiology, School of Medicine-CIMUS – Instituto de Investigaciones Sanitarias (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Carlos Diéguez
- Department of Physiology, School of Medicine-CIMUS – Instituto de Investigaciones Sanitarias (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
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Piya MK, McTernan PG, Kumar S. Adipokine inflammation and insulin resistance: the role of glucose, lipids and endotoxin. J Endocrinol 2013; 216:T1-T15. [PMID: 23160966 DOI: 10.1530/joe-12-0498] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adipose tissue is an active endocrine organ, and our knowledge of this secretory tissue, in recent years, has led us to completely rethink how our body functions and becomes dysregulated with weight gain. Human adipose tissue appears to act as a multifunctional secretory organ with the capacity to control energy homoeostasis through peripheral and central regulation of energy homoeostasis. It also plays an important role in innate immunity. However, the capability to more than double its original mass to cope with positive energy balance in obesity leads to many pathogenic changes. These changes arise within the adipose tissue as well as inducing secondary detrimental effects on other organs like muscle and liver, including chronic low-grade inflammation mediated by adipocytokines (adipokine inflammation). This inflammation is modulated by dietary factors and nutrients including glucose and lipids, as well as gut bacteria in the form of endotoxin or LPS. The aim of this current review is to consider the impact of nutrients such as glucose and lipids on inflammatory pathways, specifically within adipose tissue. Furthermore, how nutrients such as these can influence adipokine inflammation and consequently insulin resistance directly through their effects on secretion of adipocytokines (TNFα, IL6 and resistin) as well as indirectly through increases in endotoxin is discussed.
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Affiliation(s)
- M K Piya
- Division of Metabolic and Vascular Health, Clinical Sciences Research Laboratories, Warwick Medical School, University Hospital Site, University of Warwick, Coventry CV2 2DX, UK.
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Abstract
Metagenomic studies have truly revolutionised biology and medicine, and changed the way we study genomics. As genome sequencing becomes cheaper it is being applied to study complex metagenomes. 'Metagenome' is the genetic material recovered directly from an environmental sample or niche. By delivering fast, cheap, and large volumes of data Next Generation Sequencing (NGS) platforms have facilitated a deeper understanding of the fundamentals of genomes, gene functions and regulation. Metagenomics, also referred to as environmental or community genomics, has brought about radical changes in our ability to analyse complex microbial communities by direct sampling of their natural habitat paving the way for the creation of innovative new areas for biomedical research. Many metagenomic studies involving the 'human microbiome'have been undertaken to date. Samples from of a number of diverse habitats including different human body sites have been subject to metagenomic examinations. Huge national and international projects with the purpose of elucidating the biogeography of microbial communities living within and on the human body, are well underway. The analysis of human microbiome data has brought about a paradigm shift in our understanding of the role of resident microflora in human health and disease and brings non-traditional areas such as gut ecology to the forefront of personalised medicine. In this chapter we present an overview of the state-of-the-art in current literature and projects pertaining to human microbiome studies.
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Affiliation(s)
- Ramana Madupu
- Genomic Medicine group at the J. Craig Venter Institute, USA
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45
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Masgrau A, Mishellany-Dutour A, Murakami H, Beaufrère AM, Walrand S, Giraudet C, Migné C, Gerbaix M, Metz L, Courteix D, Guillet C, Boirie Y. Time-course changes of muscle protein synthesis associated with obesity-induced lipotoxicity. J Physiol 2012; 590:5199-210. [PMID: 22802586 DOI: 10.1113/jphysiol.2012.238576] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The object of the study was to investigate the sequential changes of protein synthesis in skeletal muscle during establishment of obesity, considering muscle typology. Adult Wistar rats were fed a standard diet for 16 weeks (C; n = 14), or a high-fat, high-sucrose diet for 16 (HF16; n = 14) or 24 weeks (HF24; n = 15). Body composition was measured using a dual-energy X-ray absorptiometry scanner. The fractional synthesis rates (FSRs) of muscle protein fractions were calculated in tibialis anterior (TA) and soleus muscles by incorporation of l-13C-valine in muscle protein. Muscle lipid and mitochondria contents were determined using histochemical analysis. Obesity occurred in an initial phase, from 1 to 16 weeks, with an increase in weight (P < 0.05), fat mass (P < 0.001), muscle mass (P < 0.001) and FSR in TA (actin: 5.3 ± 0.2 vs. 8.8 ± 0.5% day−1, C vs. HF16, P < 0.001) compared with standard diet. The second phase, from 16 to 24 weeks, was associated with a weight stabilization, a decrease in muscle mass (P < 0.05) and a decrease in FSR in TA (mitochondrial: 5.6 ± 0.2 vs. 4.2 ± 0.4% day−1, HF16 vs. HF24, P < 0.01) compared with HF16 group. Muscle lipid content was increased in TA in the second phase of obesity development (P < 0.001). Muscle mass, lipid infiltration and muscle protein synthesis were differently affected, depending on the stage of obesity development and muscle typology. Chronic lipid infiltration in glycolytic muscle is concomitant with a reduction of muscle protein synthesis, suggesting that muscle lipid infiltration in response to a high-fat diet is deleterious for the incorporation of amino acid in skeletal muscle proteins.
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Affiliation(s)
- Aurélie Masgrau
- French National Institute for Agricultural Research (INRA), UMR 1019, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France
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Benhamed F, Denechaud PD, Lemoine M, Robichon C, Moldes M, Bertrand-Michel J, Ratziu V, Serfaty L, Housset C, Capeau J, Girard J, Guillou H, Postic C. The lipogenic transcription factor ChREBP dissociates hepatic steatosis from insulin resistance in mice and humans. J Clin Invest 2012; 122:2176-94. [PMID: 22546860 DOI: 10.1172/jci41636] [Citation(s) in RCA: 295] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 02/15/2012] [Indexed: 12/12/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is associated with all features of the metabolic syndrome. Although deposition of excess triglycerides within liver cells, a hallmark of NAFLD, is associated with a loss of insulin sensitivity, it is not clear which cellular abnormality arises first. We have explored this in mice overexpressing carbohydrate responsive element-binding protein (ChREBP). On a standard diet, mice overexpressing ChREBP remained insulin sensitive, despite increased expression of genes involved in lipogenesis/fatty acid esterification and resultant hepatic steatosis (simple fatty liver). Lipidomic analysis revealed that the steatosis was associated with increased accumulation of monounsaturated fatty acids (MUFAs). In primary cultures of mouse hepatocytes, ChREBP overexpression induced expression of stearoyl-CoA desaturase 1 (Scd1), the enzyme responsible for the conversion of saturated fatty acids (SFAs) into MUFAs. SFA impairment of insulin-responsive Akt phosphorylation was therefore rescued by the elevation of Scd1 levels upon ChREBP overexpression, whereas pharmacological or shRNA-mediated reduction of Scd1 activity decreased the beneficial effect of ChREBP on Akt phosphorylation. Importantly, ChREBP-overexpressing mice fed a high-fat diet showed normal insulin levels and improved insulin signaling and glucose tolerance compared with controls, despite having greater hepatic steatosis. Finally, ChREBP expression in liver biopsies from patients with nonalcoholic steatohepatitis was increased when steatosis was greater than 50% and decreased in the presence of severe insulin resistance. Together, these results demonstrate that increased ChREBP can dissociate hepatic steatosis from insulin resistance, with beneficial effects on both glucose and lipid metabolism.
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Kwon CH, Rhee EJ, Song JU, Kim JT, Kwag HJ, Sung KC. Reduced lung function is independently associated with increased risk of type 2 diabetes in Korean men. Cardiovasc Diabetol 2012; 11:38. [PMID: 22524685 PMCID: PMC3464774 DOI: 10.1186/1475-2840-11-38] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/02/2012] [Indexed: 12/17/2022] Open
Abstract
Background Reduced lung function is associated with incident insulin resistance and diabetes. The aim of this study was to assess the relationship between lung function and incident type 2 diabetes in Korean men. Methods This study included 9,220 men (mean age: 41.4 years) without type 2 diabetes at baseline who were followed for five years. Subjects were divided into four groups according to baseline forced vital capacity (FVC) (% predicted) and forced expiratory volume in one second (FEV1) (% predicted) quartiles. The incidence of type 2 diabetes at follow-up was compared according to FVC and FEV1 quartiles. Results The overall incidence of type 2 diabetes was 2.2%. Reduced lung function was significantly associated with the incidence of type 2 diabetes after adjusting for age, BMI, education, smoking, exercise, alcohol, and HOMA-IR. Both FVC and FEV1 were negatively associated with type 2 diabetes (P < 0.05). In non-obese subjects with BMI < 25, the lowest quartile of FVC and FEV1 had a significantly higher odds ratio for type 2 diabetes compared with the highest quartile after adjusting for age and BMI (2.15 [95% CI 1.02-4.57] and 2.19 [95% CI 1.09-4.42]). Conclusions Reduced lung function is independently associated with the incidence of type 2 diabetes in Korean men.
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Affiliation(s)
- Chang-Hee Kwon
- Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
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