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Subramanian N, Wiik A, Rullman E, Melin M, Lundberg TR, Flanagan J, Holmberg M, Dekanski A, Dhejne C, Arver S, Gustafsson T, Laurencikiene J, Andersson DP. Adipokine secretion and lipolysis following gender-affirming treatment in transgender individuals. J Endocrinol Invest 2024:10.1007/s40618-024-02323-4. [PMID: 38460092 DOI: 10.1007/s40618-024-02323-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 01/28/2024] [Indexed: 03/11/2024]
Abstract
BACKGROUND The organ-specific effects of gender-affirming sex hormone treatment (GAHT) in transgender women (TW) and transgender men (TM) are insufficiently explored. This study investigated the effects of GAHT on adipose tissue function. METHODS In a single-center interventional prospective study, 32 adults undergoing GAHT, 15 TW and 17 TM, were examined with anthropometry and abdominal subcutaneous adipose tissue biopsies obtained before initiation of treatment, 1 month after endogenous sex hormone inhibition and three and 11 months after initiated GAHT. Fat cell size, basal/stimulated lipolysis and cytokine secretion in adipose tissue were analyzed. RESULTS TW displayed an increase in complement component 3a and retinol-binding protein 4 (RBP4) secretion after sex hormone inhibition, which returned to baseline following estradiol treatment. No changes in lipolysis were seen in TW. TM showed downregulation of RBP4 after treatment, but no changes in basal lipolysis. In TM, the estrogen suppression led to higher noradrenaline stimulated (NA) lipolysis that was normalized following testosterone treatment. At 11 months, the ratio of NA/basal lipolysis was lower compared to baseline. There were no significant changes in fat cell size in either TW or TM. CONCLUSION In TW, gonadal hormone suppression results in transient changes in cytokines and in TM there are some changes in NA-stimulated lipolysis following testosterone treatment. However, despite the known metabolic effects of sex hormones, the overall effects of GAHT on adipose tissue function are small and likely have limited clinical relevance, but larger studies with longer follow-up are needed to confirm these findings. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02518009, Retrospectively registered 7 August 2015.
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Affiliation(s)
- N Subramanian
- Lipid Laboratory, Department of Medicine Huddinge (H7), Karolinska Institutet, C2:94, Karolinska University Hospital Huddinge, 141 86, Huddinge, Sweden
| | - A Wiik
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - E Rullman
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - M Melin
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
- Department of Cardiology, Heart and Vascular Center, Karolinska University Hospital, Stockholm, Sweden
| | - T R Lundberg
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - J Flanagan
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - M Holmberg
- Lipid Laboratory, Department of Medicine Huddinge (H7), Karolinska Institutet, C2:94, Karolinska University Hospital Huddinge, 141 86, Huddinge, Sweden
- ANOVA, Andrology, Sexual Medicine and Transgender Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - A Dekanski
- Lipid Laboratory, Department of Medicine Huddinge (H7), Karolinska Institutet, C2:94, Karolinska University Hospital Huddinge, 141 86, Huddinge, Sweden
| | - C Dhejne
- ANOVA, Andrology, Sexual Medicine and Transgender Medicine, Karolinska University Hospital, Stockholm, Sweden
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - S Arver
- ANOVA, Andrology, Sexual Medicine and Transgender Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - T Gustafsson
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - J Laurencikiene
- Lipid Laboratory, Department of Medicine Huddinge (H7), Karolinska Institutet, C2:94, Karolinska University Hospital Huddinge, 141 86, Huddinge, Sweden
| | - D P Andersson
- Lipid Laboratory, Department of Medicine Huddinge (H7), Karolinska Institutet, C2:94, Karolinska University Hospital Huddinge, 141 86, Huddinge, Sweden.
- Department of Endocrinology, Karolinska University Hospital Huddinge, Stockholm, Sweden.
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Dabas J, Shunmukha Priya S, Alawani A, Budhrani P. What could be the reasons for not losing weight even after following a weight loss program? JOURNAL OF HEALTH, POPULATION, AND NUTRITION 2024; 43:37. [PMID: 38429842 PMCID: PMC10908186 DOI: 10.1186/s41043-024-00516-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/28/2024] [Indexed: 03/03/2024]
Abstract
INTRODUCTION Approximately four million people worldwide die annually because of obesity. Weight loss is commonly recommended as a first-line therapy in overweight and obese patients. Although many individuals attempt to lose weight, not everyone achieves optimal success. Few studies point out that weight loss eventually slows down, stagnates or reverses in 85% of the cases. RESEARCH QUESTION What could be the reasons for not losing weight even after following a weight loss program? METHODS A scoping review of the literature was performed using weight loss-related search terms such as 'Obesity,' 'Overweight,' 'Lifestyle,' 'weight loss,' 'Basal Metabolism,' 'physical activity,' 'adherence,' 'energy balance,' 'Sleep' and 'adaptations. The search involved reference tracking and database and web searches (PUBMED, Science Direct, Elsevier, Web of Science and Google Scholar). Original articles and review papers on weight loss involving human participants and adults aged > 18 years were selected. Approximately 231 articles were reviewed, and 185 were included based on the inclusion criteria. DESIGN Scoping review. RESULTS In this review, the factors associated with not losing weight have broadly been divided into five categories. Studies highlighting each subfactor were critically reviewed and discussed. A wide degree of interindividual variability in weight loss is common in studies even after controlling for variables such as adherence, sex, physical activity and baseline weight. In addition to these variables, variations in factors such as previous weight loss attempts, sleep habits, meal timings and medications can play a crucial role in upregulating or downregulating the association between energy deficit and weight loss results. CONCLUSION This review identifies and clarifies the role of several factors that may hinder weight loss after the exploration of existing evidence. Judging the effectiveness of respective lifestyle interventions by simply observing the 'general behavior of the groups' is not always applicable in clinical practice. Each individual must be monitored and advised as per their requirements and challenges.
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Affiliation(s)
- Jyoti Dabas
- Institute of Nutrition and Fitness Sciences, Platinum Square, 4th floor, Office, 403, Opp. WNS, Sakore Nagar, Viman Nagar, Pune, Maharashtra, 411014, India
| | - S Shunmukha Priya
- Institute of Nutrition and Fitness Sciences, Platinum Square, 4th floor, Office, 403, Opp. WNS, Sakore Nagar, Viman Nagar, Pune, Maharashtra, 411014, India.
| | - Akshay Alawani
- Institute of Nutrition and Fitness Sciences, Platinum Square, 4th floor, Office, 403, Opp. WNS, Sakore Nagar, Viman Nagar, Pune, Maharashtra, 411014, India
| | - Praveen Budhrani
- Institute of Nutrition and Fitness Sciences, Platinum Square, 4th floor, Office, 403, Opp. WNS, Sakore Nagar, Viman Nagar, Pune, Maharashtra, 411014, India
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Shah R, Zhong J, Massier L, Tanriverdi K, Hwang SJ, Haessler J, Nayor M, Zhao S, Perry AS, Wilkins JT, Shadyab AH, Manson JE, Martin L, Levy D, Kooperberg C, Freedman JE, Rydén M, Murthy VL. Targeted Proteomics Reveals Functional Targets for Early Diabetes Susceptibility in Young Adults. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2024; 17:e004192. [PMID: 38323454 PMCID: PMC10940209 DOI: 10.1161/circgen.123.004192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 11/05/2023] [Indexed: 02/08/2024]
Abstract
BACKGROUND The circulating proteome may encode early pathways of diabetes susceptibility in young adults for surveillance and intervention. Here, we define proteomic correlates of tissue phenotypes and diabetes in young adults. METHODS We used penalized models and principal components analysis to generate parsimonious proteomic signatures of diabetes susceptibility based on phenotypes and on diabetes diagnosis across 184 proteins in >2000 young adults in the CARDIA (Coronary Artery Risk Development in Young Adults study; mean age, 32 years; 44% women; 43% Black; mean body mass index, 25.6±4.9 kg/m2), with validation against diabetes in >1800 individuals in the FHS (Framingham Heart Study) and WHI (Women's Health Initiative). RESULTS In 184 proteins in >2000 young adults in CARDIA, we identified 2 proteotypes of diabetes susceptibility-a proinflammatory fat proteotype (visceral fat, liver fat, inflammatory biomarkers) and a muscularity proteotype (muscle mass), linked to diabetes in CARDIA and WHI/FHS. These proteotypes specified broad mechanisms of early diabetes pathogenesis, including transorgan communication, hepatic and skeletal muscle stress responses, vascular inflammation and hemostasis, fibrosis, and renal injury. Using human adipose tissue single cell/nuclear RNA-seq, we demonstrate expression at transcriptional level for implicated proteins across adipocytes and nonadipocyte cell types (eg, fibroadipogenic precursors, immune and vascular cells). Using functional assays in human adipose tissue, we demonstrate the association of expression of genes encoding these implicated proteins with adipose tissue metabolism, inflammation, and insulin resistance. CONCLUSIONS A multifaceted discovery effort uniting proteomics, underlying clinical susceptibility phenotypes, and tissue expression patterns may uncover potentially novel functional biomarkers of early diabetes susceptibility in young adults for future mechanistic evaluation.
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Affiliation(s)
- Ravi Shah
- Vanderbilt Translational & Clinical Cardiovascular Research Center, Vanderbilt Univ, Nashville, TN
| | - Jiawei Zhong
- Dept of Medicine (H7), Karolinska Institutet, Stockholm, Sweden
| | - Lucas Massier
- Dept of Medicine (H7), Karolinska Institutet, Stockholm, Sweden
| | - Kahraman Tanriverdi
- Vanderbilt Translational & Clinical Cardiovascular Research Center, Vanderbilt Univ, Nashville, TN
| | - Shih-Jen Hwang
- Population Sciences Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | | | - Matthew Nayor
- Sections of Preventive Medicine & Epidemiology & Cardiovascular Medicine, Dept of Medicine, Dept of Epidemiology, Boston University Schools of Medicine & Public Health, Boston, MA & Framingham Heart Study, Framingham, MA
| | | | - Andrew S. Perry
- Vanderbilt Translational & Clinical Cardiovascular Research Center, Vanderbilt Univ, Nashville, TN
| | | | - Aladdin H. Shadyab
- Herbert Wertheim School of Public Health & Human Longevity Science, Univ of California, San Diego, La Jolla, CA
| | - JoAnn E. Manson
- Dept of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Lisa Martin
- George Washington Univ School of Medicine & Health Sciences
| | - Daniel Levy
- Population Sciences Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | | | - Jane E. Freedman
- Vanderbilt Translational & Clinical Cardiovascular Research Center, Vanderbilt Univ, Nashville, TN
| | - Mikael Rydén
- Dept of Medicine (H7), Karolinska Institutet, Stockholm, Sweden
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Subramanian N, Hofwimmer K, Tavira B, Massier L, Andersson DP, Arner P, Laurencikiene J. Adipose tissue specific CCL18 associates with cardiometabolic diseases in non-obese individuals implicating CD4 + T cells. Cardiovasc Diabetol 2023; 22:84. [PMID: 37046242 PMCID: PMC10099890 DOI: 10.1186/s12933-023-01803-w] [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: 01/24/2023] [Accepted: 03/16/2023] [Indexed: 04/14/2023] Open
Abstract
AIM Obesity is linked to cardiometabolic diseases, however non-obese individuals are also at risk for type 2 diabetes (T2D) and cardiovascular disease (CVD). White adipose tissue (WAT) is known to play a role in both T2D and CVD, but the contribution of WAT inflammatory status especially in non-obese patients with cardiometabolic diseases is less understood. Therefore, we aimed to find associations between WAT inflammatory status and cardiometabolic diseases in non-obese individuals. METHODS In a population-based cohort containing non-obese healthy (n = 17), T2D (n = 16), CVD (n = 18), T2D + CVD (n = 19) individuals, seventeen different cytokines were measured in WAT and in circulation. In addition, 13-color flow cytometry profiling was employed to phenotype the immune cells. Human T cell line (Jurkat T cells) was stimulated by rCCL18, and conditioned media (CM) was added to the in vitro cultures of human adipocytes. Lipolysis was measured by glycerol release. Blocking antibodies against IFN-γ and TGF-β were used in vitro to prove a role for these cytokines in CCL18-T-cell-adipocyte lipolysis regulation axis. RESULTS In CVD, T2D and CVD + T2D groups, CCL18 and CD4+ T cells were upregulated significantly compared to healthy controls. WAT CCL18 secretion correlated with the amounts of WAT CD4+ T cells, which also highly expressed CCL18 receptors suggesting that WAT CD4+ T cells are responders to this chemokine. While direct addition of rCCL18 to mature adipocytes did not alter the adipocyte lipolysis, CM from CCL18-treated T cells increased glycerol release in in vitro cultures of adipocytes. IFN-γ and TGF-β secretion was significantly induced in CM obtained from T cells treated with CCL18. Blocking these cytokines in CM, prevented CM-induced upregulation of adipocyte lipolysis. CONCLUSION We suggest that in T2D and CVD, increased production of CCL18 recruits and activates CD4+ T cells to secrete IFN-γ and TGF-β. This, in turn, promotes adipocyte lipolysis - a possible risk factor for cardiometabolic diseases.
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Affiliation(s)
- Narmadha Subramanian
- Lipid laboratory, Unit of Endocrinology, Dept. of Medicine Huddinge, Karolinska Institutet, Stockholm, 141 86, Sweden
| | - Kaisa Hofwimmer
- Lipid laboratory, Unit of Endocrinology, Dept. of Medicine Huddinge, Karolinska Institutet, Stockholm, 141 86, Sweden
| | - Beatriz Tavira
- Lipid laboratory, Unit of Endocrinology, Dept. of Medicine Huddinge, Karolinska Institutet, Stockholm, 141 86, Sweden
| | - Lucas Massier
- Lipid laboratory, Unit of Endocrinology, Dept. of Medicine Huddinge, Karolinska Institutet, Stockholm, 141 86, Sweden
| | - Daniel P Andersson
- Lipid laboratory, Unit of Endocrinology, Dept. of Medicine Huddinge, Karolinska Institutet, Stockholm, 141 86, Sweden
| | - Peter Arner
- Lipid laboratory, Unit of Endocrinology, Dept. of Medicine Huddinge, Karolinska Institutet, Stockholm, 141 86, Sweden
| | - Jurga Laurencikiene
- Lipid laboratory, Unit of Endocrinology, Dept. of Medicine Huddinge, Karolinska Institutet, Stockholm, 141 86, Sweden.
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Rydén M, Andersson DP, Kotopouli MI, Stenberg E, Näslund E, Thorell A, Sørensen TIA, Arner P. Lipolysis defect in people with obesity who undergo metabolic surgery. J Intern Med 2022; 292:667-678. [PMID: 35670497 PMCID: PMC9540545 DOI: 10.1111/joim.13527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Cross-sectional studies demonstrate that catecholamine stimulation of fat cell lipolysis is blunted in obesity. We investigated whether this defect persists after substantial weight loss has been induced by metabolic surgery, and whether it is related to the outcome. DESIGN/METHODS Patients with obesity not able to successfully reduce body weight by conventional means (n = 126) were investigated before and 5 years after Roux-en-Y gastric bypass surgery (RYGB). They were compared with propensity-score matched subjects selected from a control group (n = 1017), and with the entire group after adjustment for age, sex, body mass index (BMI), fat cell volume and other clinical parameters. Catecholamine-stimulated lipolysis (glycerol release) was investigated in isolated fat cells using noradrenaline (natural hormone) or isoprenaline (synthetic beta-adrenoceptor agonist). RESULTS Following RYGB, BMI was reduced from 39.9 (37.5-43.5) (median and interquartile range) to 29.5 (26.7-31.9) kg/m2 (p < 0.0001). The post-RYGB patients had about 50% lower lipolysis rates compared with the matched and total series of controls (p < 0.0005). Nordrenaline activation of lipolysis at baseline was associated with the RYGB effect; those with high lipolysis activation (upper tertile) lost 30%-45% more in body weight, BMI or fat mass than those with low (bottom tertile) initial lipolysis activation (p < 0.0007). CONCLUSION Patients with obesity requiring metabolic surgery have impaired ability of catecholamines to stimulate lipolysis, which remains despite long-term normalization of body weight by RYGB. Furthermore, preoperative variations in the ability of catecholamines to activate lipolysis may predict the long-term reduction in body weight and fat mass.
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Affiliation(s)
- Mikael Rydén
- Department of Medicine (H7), Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Daniel P Andersson
- Department of Medicine (H7), Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Maria I Kotopouli
- Division of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Erik Stenberg
- Department of Surgery, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Erik Näslund
- Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Anders Thorell
- Department of Clinical Sciences, Danderyds Hospital, Karolinska Institutet, Stockholm, Sweden.,Department of Surgery, Ersta Hospital, Stockholm, Sweden
| | - Thorkild I A Sørensen
- Novo Nordisk Foundation Centre for Basic Metabolic Research and Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Arner
- Department of Medicine (H7), Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
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Ye RZ, Richard G, Gévry N, Tchernof A, Carpentier AC. Fat Cell Size: Measurement Methods, Pathophysiological Origins, and Relationships With Metabolic Dysregulations. Endocr Rev 2022; 43:35-60. [PMID: 34100954 PMCID: PMC8755996 DOI: 10.1210/endrev/bnab018] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Indexed: 11/19/2022]
Abstract
The obesity pandemic increasingly causes morbidity and mortality from type 2 diabetes, cardiovascular diseases and many other chronic diseases. Fat cell size (FCS) predicts numerous obesity-related complications such as lipid dysmetabolism, ectopic fat accumulation, insulin resistance, and cardiovascular disorders. Nevertheless, the scarcity of systematic literature reviews on this subject is compounded by the use of different methods by which FCS measurements are determined and reported. In this paper, we provide a systematic review of the current literature on the relationship between adipocyte hypertrophy and obesity-related glucose and lipid dysmetabolism, ectopic fat accumulation, and cardiovascular disorders. We also review the numerous mechanistic origins of adipocyte hypertrophy and its relationship with metabolic dysregulation, including changes in adipogenesis, cell senescence, collagen deposition, systemic inflammation, adipokine secretion, and energy balance. To quantify the effect of different FCS measurement methods, we performed statistical analyses across published data while controlling for body mass index, age, and sex.
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Affiliation(s)
- Run Zhou Ye
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Gabriel Richard
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Nicolas Gévry
- Department of Biology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - André Tchernof
- Québec Heart and Lung Research Institute, Laval University, Québec, Québec, Canada
| | - André C Carpentier
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
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A longitudinal study of the antilipolytic effect of insulin in women following bariatric surgery. Int J Obes (Lond) 2021; 45:2675-2678. [PMID: 34321614 PMCID: PMC8606310 DOI: 10.1038/s41366-021-00914-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/08/2022]
Abstract
Insulin resistance of glucose utilization is fully restored following BMI normalization after bariatric surgery. We investigated if this also pertains to insulin-induced effects on fatty acid handling. Forty-three women with obesity (OB) were investigated before and 2 years after Roux-en-Y gastric by-pass when BMI was <30 kg/m2 (PO) and compared with 26 never obese women (NO). The Adipo-IR index was used as measure of insulin antilipolytic sensitivity. Changes (delta) in circulating glycerol and fatty acid levels during hyperinsulinemic euglycemic clamp represented the insulin maximum antilipolytic effect. Overall fatty acid utilization was reflected by delta fatty acids minus 3 × delta glycerol. Adipo-IR was higher in OB than in NO and PO (p < 0.0001), the latter two groups having similar values. Insulin lowered glycerol levels by about 70% in all groups, but delta glycerol was 30% larger in PO than in NO (p = 0.04). Delta adds and adds utilization were similar in all groups. We conclude that women with obesity, whose BMI is normalized after bariatric surgery, have improved maximum in vivo antilipolytic effect of insulin above expected in absolute but not relative terms as regards glycerol changes, while the handling of circulating fatty acids is changed to the normal state.
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LRIG proteins regulate lipid metabolism via BMP signaling and affect the risk of type 2 diabetes. Commun Biol 2021; 4:90. [PMID: 33469151 PMCID: PMC7815736 DOI: 10.1038/s42003-020-01613-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 12/17/2020] [Indexed: 02/06/2023] Open
Abstract
Leucine-rich repeats and immunoglobulin-like domains (LRIG) proteins have been implicated as regulators of growth factor signaling; however, the possible redundancy among mammalian LRIG1, LRIG2, and LRIG3 has hindered detailed elucidation of their physiological functions. Here, we show that Lrig-null mouse embryonic fibroblasts (MEFs) are deficient in adipogenesis and bone morphogenetic protein (BMP) signaling. In contrast, transforming growth factor-beta (TGF-β) and receptor tyrosine kinase (RTK) signaling appeared unaltered in Lrig-null cells. The BMP signaling defect was rescued by ectopic expression of LRIG1 or LRIG3 but not by expression of LRIG2. Caenorhabditis elegans with mutant LRIG/sma-10 variants also exhibited a lipid storage defect. Human LRIG1 variants were strongly associated with increased body mass index (BMI) yet protected against type 2 diabetes; these effects were likely mediated by altered adipocyte morphology. These results demonstrate that LRIG proteins function as evolutionarily conserved regulators of lipid metabolism and BMP signaling and have implications for human disease.
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Grapov D, Fiehn O, Campbell C, Chandler CJ, Burnett DJ, Souza EC, Casazza GA, Keim NL, Hunter GR, Fernandez JR, Garvey WT, Hoppel CL, Harper M, Newman JW, Adams SH. Impact of a weight loss and fitness intervention on exercise-associated plasma oxylipin patterns in obese, insulin-resistant, sedentary women. Physiol Rep 2020; 8:e14547. [PMID: 32869956 PMCID: PMC7460071 DOI: 10.14814/phy2.14547] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/26/2020] [Accepted: 07/27/2020] [Indexed: 12/18/2022] Open
Abstract
Very little is known about how metabolic health status, insulin resistance or metabolic challenges modulate the endocannabinoid (eCB) or polyunsaturated fatty acid (PUFA)-derived oxylipin (OxL) lipid classes. To address these questions, plasma eCB and OxL concentrations were determined at rest, 10 and 20 min during an acute exercise bout (30 min total, ~45% of preintervention V̇O2peak , ~63 W), and following 20 min recovery in overnight-fasted sedentary, obese, insulin-resistant women under controlled diet conditions. We hypothesized that increased fitness and insulin sensitivity following a ~14-week training and weight loss intervention would lead to significant changes in lipid signatures using an identical acute exercise protocol to preintervention. In the first 10 min of exercise, concentrations of a suite of OxL diols and hydroxyeicosatetraenoic acid (HETE) metabolites dropped significantly. There was no increase in 12,13-DiHOME, previously reported to increase with exercise and proposed to activate muscle fatty acid uptake and tissue metabolism. Following weight loss intervention, exercise-associated reductions were more pronounced for several linoleate and alpha-linolenate metabolites including DiHOMEs, DiHODEs, KODEs, and EpODEs, and fasting concentrations of 9,10-DiHODE, 12,13-DiHODE, and 9,10-DiHOME were reduced. These findings suggest that improved metabolic health modifies soluble epoxide hydrolase, cytochrome P450 epoxygenase (CYP), and lipoxygenase (LOX) systems. Acute exercise led to reductions for most eCB metabolites, with no evidence for concentration increases even at recovery. It is proposed that during submaximal aerobic exercise, nonoxidative fates of long-chain saturated, monounsaturated, and PUFAs are attenuated in tissues that are important contributors to the blood OxL and eCB pools.
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Affiliation(s)
| | - Oliver Fiehn
- West Coast Metabolomics CenterUniversity of CaliforniaDavisCAUSA
| | - Caitlin Campbell
- United States Department of Agriculture‐Agricultural Research Service Western Human Nutrition Research CenterDavisCAUSA
| | - Carol J. Chandler
- United States Department of Agriculture‐Agricultural Research Service Western Human Nutrition Research CenterDavisCAUSA
| | - Dustin J. Burnett
- United States Department of Agriculture‐Agricultural Research Service Western Human Nutrition Research CenterDavisCAUSA
| | - Elaine C. Souza
- United States Department of Agriculture‐Agricultural Research Service Western Human Nutrition Research CenterDavisCAUSA
| | | | - Nancy L. Keim
- United States Department of Agriculture‐Agricultural Research Service Western Human Nutrition Research CenterDavisCAUSA
- Department of NutritionUniversity of CaliforniaDavisCAUSA
| | - Gary R. Hunter
- Department of Nutrition SciencesUniversity of AlabamaBirminghamALUSA
- Human Studies DepartmentUniversity of AlabamaBirminghamALUSA
| | - Jose R. Fernandez
- Department of Nutrition SciencesUniversity of AlabamaBirminghamALUSA
| | - W. Timothy Garvey
- Department of Nutrition SciencesUniversity of AlabamaBirminghamALUSA
| | - Charles L. Hoppel
- Pharmacology DepartmentCase Western Reserve UniversityClevelandOHUSA
| | - Mary‐Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, and Ottawa Institute of Systems BiologyUniversity of OttawaOttawaONCanada
| | - John W. Newman
- United States Department of Agriculture‐Agricultural Research Service Western Human Nutrition Research CenterDavisCAUSA
- Department of NutritionUniversity of CaliforniaDavisCAUSA
| | - Sean H. Adams
- Arkansas Children’s Nutrition CenterLittle RockARUSA
- Department of PediatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
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Kulyté A, Lundbäck V, Lindgren CM, Luan J, Lotta LA, Langenberg C, Arner P, Strawbridge RJ, Dahlman I. Genome-wide association study of adipocyte lipolysis in the GENetics of adipocyte lipolysis (GENiAL) cohort. Mol Metab 2020; 34:85-96. [PMID: 32180562 PMCID: PMC7021539 DOI: 10.1016/j.molmet.2020.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/25/2019] [Accepted: 01/15/2020] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Lipolysis, hydrolysis of triglycerides to fatty acids in adipocytes, is tightly regulated, poorly understood, and, if perturbed, can lead to metabolic diseases including obesity and type 2 diabetes. The goal of this study was to identify the genetic regulators of lipolysis and elucidate their molecular mechanisms. METHODS Adipocytes from abdominal subcutaneous adipose tissue biopsies were isolated and were incubated without (spontaneous lipolysis) or with a catecholamine (stimulated lipolysis) to analyze lipolysis. DNA was extracted and genome-wide genotyping and imputation conducted. After quality control, 939 samples with genetic and lipolysis data were available. Genome-wide association studies of spontaneous and stimulated lipolysis were conducted. Subsequent in vitro gene expression analyses were used to identify candidate genes and explore their regulation of adipose tissue biology. RESULTS One locus on chromosome 19 demonstrated genome-wide significance with spontaneous lipolysis. 60 loci showed suggestive associations with spontaneous or stimulated lipolysis, of which many influenced both traits. In the chromosome 19 locus, only HIF3A was expressed in the adipocytes and displayed genotype-dependent gene expression. HIF3A knockdown in vitro increased lipolysis and the expression of key lipolysis-regulating genes. CONCLUSIONS In conclusion, we identified a genetic regulator of spontaneous lipolysis and provided evidence of HIF3A as a novel key regulator of lipolysis in subcutaneous adipocytes as the mechanism through which the locus influences adipose tissue biology.
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Affiliation(s)
- Agné Kulyté
- Lipid laboratory, Department of Medicine Huddinge, Karolinska Institute, Stockholm, Sweden
| | - Veroniqa Lundbäck
- Lipid laboratory, Department of Medicine Huddinge, Karolinska Institute, Stockholm, Sweden
| | - Cecilia M Lindgren
- Big Data Institute at the Li Ka Shing Center for Health Information and Discovery, University of Oxford, Oxford, UK; Wellcome Center for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK; National Institute for Health Research Oxford Biomedical Research Center, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
| | - Jian'an Luan
- MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Luca A Lotta
- MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | | | - Peter Arner
- Lipid laboratory, Department of Medicine Huddinge, Karolinska Institute, Stockholm, Sweden
| | - Rona J Strawbridge
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK; Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden; Health Data Research UK, UK
| | - Ingrid Dahlman
- Lipid laboratory, Department of Medicine Huddinge, Karolinska Institute, Stockholm, Sweden.
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11
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Rydén M, Gao H, Arner P. Influence of Aging and Menstrual Status on Subcutaneous Fat Cell Lipolysis. J Clin Endocrinol Metab 2020; 105:5648098. [PMID: 31784744 DOI: 10.1210/clinem/dgz245] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/28/2019] [Indexed: 12/11/2022]
Abstract
CONTEXT Aging is accompanied by inhibited fat cell mobilization of fatty acids through lipolysis, which may contribute to decreased energy expenditure in elderly subjects. However, the influence of menstrual status is unknown. OBJECTIVE To investigate the role of menstrual status on changes in lipolysis induced by aging. DESIGN A longitudinal investigation with a mean 13-year interval. SETTING Ambulatory study at a clinical academic unit. PARTICIPANTS Eighty-two continuously recruited women between 24 and 62 years of age and with body mass index 21 to 48 kg/m2 at first examination. Twenty-nine women continued to have normal menstruation, 42 developed irregular menstruation/menopause, and 11 had a perimenstrual/menopausal phenotype already at the first examination. MAIN OUTCOME MEASURE Lipolysis measured as glycerol release from isolated subcutaneous fat cells incubated in vitro. RESULTS On average, body weight/body fat mass levels did not change over time. In all 3 groups, aging was associated with a similar decrease in spontaneous (basal) and catecholamine-stimulated lipolysis. The latter was due to decreased signal transduction through stimulatory beta adrenoceptors and increased alpha-2-adrenoceptor-mediated antilipolytic effects. Gene microarray data from adipose tissue at baseline and follow-up (n = 53) showed that a limited set of lipolysis-linked genes, including phosphodiesterase-3B, were altered over time, but this was independent of menstrual status. Fat cell size also decreased during aging, but this could not explain the decrease in lipolysis. CONCLUSIONS In women, the rate of fat cell lipolysis decreases during aging due to multiple alterations in spontaneous (basal) and catecholamine-induced lipolysis. This is independent of changes in menstrual status or fat cell size.
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Affiliation(s)
- Mikael Rydén
- Department of Medicine (H7), Karolinska Institutet at Karolinska University Hospital-Huddinge, Stockholm, Sweden
| | - Hui Gao
- Department of Medicine (H7), Karolinska Institutet at Karolinska University Hospital-Huddinge, Stockholm, Sweden
| | - Peter Arner
- Department of Medicine (H7), Karolinska Institutet at Karolinska University Hospital-Huddinge, Stockholm, Sweden
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12
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Short-Term Caloric Restriction Attenuates Obesity-Induced Pro-Inflammatory Response in Male Rhesus Macaques. Nutrients 2020; 12:nu12020511. [PMID: 32085416 PMCID: PMC7071433 DOI: 10.3390/nu12020511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/14/2020] [Accepted: 02/14/2020] [Indexed: 12/12/2022] Open
Abstract
White adipose tissue (WAT) hypertrophy is an essential hallmark of obesity and is associated with the activation of resident immune cells. While the benefits of caloric restriction (CR) on health span are generally accepted, its effects on WAT physiology are not well understood. We previously demonstrated that short-term CR reverses obesity in male rhesus macaques exposed to a high-fat Western-style diet (WSD). Here, we analyzed subcutaneous WAT biopsies collected from this cohort of animals before and after WSD and following CR. This analysis showed that WSD induced adipocyte hypertrophy and inhibited β-adrenergic-simulated lipolysis. CR reversed adipocyte hypertrophy, but WAT remained insensitive to β-adrenergic agonist stimulation. Whole-genome transcriptional analysis revealed that β3-adrenergic receptor and de novo lipogenesis genes were downregulated by WSD and remained downregulated after CR. In contrast, WSD-induced pro-inflammatory gene expression was effectively reversed by CR. Furthermore, peripheral blood monocytes isolated during the CR period exhibited a significant reduction in the production of pro-inflammatory cytokines compared to those obtained after WSD. Collectively, this study demonstrates that short-term CR eliminates an obesity-induced pro-inflammatory response in WAT and peripheral monocytes.
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13
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Rydén M, Petrus P, Andersson DP, Medina-Gómez G, Escasany E, Corrales Cordón P, Dahlman I, Kulyté A, Arner P. Insulin action is severely impaired in adipocytes of apparently healthy overweight and obese subjects. J Intern Med 2019; 285:578-588. [PMID: 30758089 DOI: 10.1111/joim.12887] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Many overweight/obese subjects appear metabolically healthy with normal in vivo insulin sensitivity. Still, they have increased long-term risk of developing type 2 diabetes. We hypothesized that adipose tissue dysfunction involving decreased insulin action in adipocytes is present in apparently healthy overweight/obese subjects. DESIGN/METHODS Subjects with normal metabolic health according to Adult Treatment Panel-III or Framingham risk score criteria were subdivided into 67 lean, 32 overweight and 37 obese according to body mass index. They were compared with 200 obese individuals with metabolic syndrome. Insulin sensitivity and maximum action on inhibition of lipolysis and stimulation of lipogenesis was determined in subcutaneous adipocytes. Gene expression was determined by micro-array and qPCR. DNA methylation was assessed by array, pyrosequencing and reporter assays. RESULTS Compared with lean, adipocytes in overweight/obese displayed marked reductions in insulin sensitivity in both antilipolysis and lipogenesis as well as an attenuated maximum lipogenic response. Among these, only antilipolysis sensitivity correlated with whole-body insulin sensitivity. These differences were already evident in the overweight state, were only slightly worse in the unhealthy obese state and were not related to fat cell size. Adipose tissue analyses linked this to reduced expression of the insulin signalling protein AKT2, which associated with increased methylation at regulatory sites in the AKT2 promoter. CONCLUSIONS Apparently healthy subjects have severely disturbed adipocyte insulin signalling already in the overweight state which involves epigenetic dysregulation of AKT2. This may constitute an early defect in insulin action that appears even upon modest increases in fat mass.
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Affiliation(s)
- M Rydén
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - P Petrus
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - D P Andersson
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - G Medina-Gómez
- Departamento de Ciencias Básicas de la Salud, Área Bioquímica y Biología Molecular, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Madrid, Spain
| | - E Escasany
- Departamento de Ciencias Básicas de la Salud, Área Bioquímica y Biología Molecular, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Madrid, Spain
| | - P Corrales Cordón
- Departamento de Ciencias Básicas de la Salud, Área Bioquímica y Biología Molecular, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Madrid, Spain
| | - I Dahlman
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - A Kulyté
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - P Arner
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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14
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Kerr AG, Sinha I, Dadvar S, Arner P, Dahlman I. Epigenetic regulation of diabetogenic adipose morphology. Mol Metab 2019; 25:159-167. [PMID: 31031182 PMCID: PMC6600120 DOI: 10.1016/j.molmet.2019.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 04/13/2019] [Indexed: 12/17/2022] Open
Abstract
Objective Hypertrophic white adipose tissue (WAT) morphology is associated with insulin resistance and type 2 diabetes. The mechanisms governing hyperplastic versus hypertrophic WAT expansion are poorly understood. We assessed if epigenetic modifications in adipocytes are associated with hypertrophic adipose morphology. A subset of genes with differentially methylated CpG-sites (DMS) in the promoters was taken forward for functional evaluation. Methods The study included 126 women who underwent abdominal subcutaneous biopsy to determine adipose morphology. Global transcriptome profiling was performed on WAT from 113 of the women, and CpG methylome profiling on isolated adipocytes from 78 women. Small interfering RNAs (siRNA) knockdown in human mesenchymal stem cells (hMSCs) was used to assess influence of specific genes on lipid storage. Results A higher proportion of CpG-sites were methylated in hypertrophic compared to hyperplastic WAT. Methylation at 35,138 CpG-sites was found to correlate to adipose morphology. 2,102 of these CpG-sites were also differentially methylated in T2D; 98% showed directionally consistent change in methylation in WAT hypertrophy and T2D. We identified 2,508 DMS in 638 adipose morphology-associated genes where methylation correlated with gene expression. These genes were over-represented in gene sets relevant to WAT hypertrophy, such as insulin resistance, lipolysis, extracellular matrix organization, and innate immunity. siRNA knockdown of ADH1B, AZGP1, C14orf180, GYG2, HADH, PRKAR2B, PFKFB3, and AQP7 influenced lipid storage and metabolism. Conclusion CpG methylation could be influential in determining adipose morphology and thereby constitute a novel antidiabetic target. We identified C14orf180 as a novel regulator of adipocyte lipid storage and possibly differentiation. Hypertrophic adipose morphology display a distinct adipocyte CpG-methylome profile. Adipose hypertrophy and type 2 diabetes display strong overlap in CpG-methylome profile. C14orf180 is a novel regulator of adipocyte lipid storage and possibly adipogenesis.
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Affiliation(s)
- A G Kerr
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - I Sinha
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - S Dadvar
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - P Arner
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - I Dahlman
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden.
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15
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Peos JJ, Norton LE, Helms ER, Galpin AJ, Fournier P. Intermittent Dieting: Theoretical Considerations for the Athlete. Sports (Basel) 2019; 7:sports7010022. [PMID: 30654501 PMCID: PMC6359485 DOI: 10.3390/sports7010022] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/05/2019] [Accepted: 01/11/2019] [Indexed: 12/28/2022] Open
Abstract
Athletes utilise numerous strategies to reduce body weight or body fat prior to competition. The traditional approach requires continuous energy restriction (CER) for the entire weight loss phase (typically days to weeks). However, there is some suggestion that intermittent energy restriction (IER), which involves alternating periods of energy restriction with periods of greater energy intake (referred to as ‘refeeds’ or ‘diet breaks’) may result in superior weight loss outcomes than CER. This may be due to refeed periods causing transitory restoration of energy balance. Some studies indicate that intermittent periods of energy balance during energy restriction attenuate some of the adaptive responses that resist the continuation of weight and fat loss. While IER—like CER—is known to effectively reduce body fat in non-athletes, evidence for effectiveness of IER in athletic populations is lacking. This review provides theoretical considerations for successful body composition adjustment using IER, with discussion of how the limited existing evidence can be cautiously applied in athlete practice.
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Affiliation(s)
- Jackson James Peos
- The University of Western Australia (UWA), The School of Human Sciences, Crawley Campus, WA 6009, USA.
| | | | - Eric Russell Helms
- Auckland University of Technology, Sports Performance Institute New Zealand (SPRINZ) at AUT Millennium, Auckland 0632, New Zealand.
| | - Andrew Jacob Galpin
- California State University, Biochemistry and Molecular Exercise Physiology Laboratory, Centre for Sport Performance, Fullerton, CA 92831, USA.
| | - Paul Fournier
- The University of Western Australia (UWA), The School of Human Sciences, Crawley Campus, WA 6009, USA.
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16
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Arner P, Andersson DP, Bäckdahl J, Dahlman I, Rydén M. Weight Gain and Impaired Glucose Metabolism in Women Are Predicted by Inefficient Subcutaneous Fat Cell Lipolysis. Cell Metab 2018; 28:45-54.e3. [PMID: 29861390 DOI: 10.1016/j.cmet.2018.05.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/13/2018] [Accepted: 05/03/2018] [Indexed: 12/14/2022]
Abstract
Adipocyte mobilization of fatty acids (lipolysis) is instrumental for energy expenditure. Lipolysis displays both spontaneous (basal) and hormone-stimulated activity. It is unknown if lipolysis is important for future body weight gain and associated disturbed glucose metabolism, and this was presently investigated in subcutaneous adipocytes from two female cohorts before and after ≥10-year follow-up. High basal and low stimulated lipolysis at baseline predicted future weight gain (odds ratios ≥4.6) as well as development of insulin resistance and impaired fasting glucose/type 2 diabetes (odds ratios ≥3.2). At baseline, weight gainers displayed lower adipose expression of several established lipolysis-regulating genes. Thus, inefficient lipolysis (high basal/low stimulated) involving altered gene expression is linked to future weight gain and impaired glucose metabolism and may constitute a treatment target. Finally, low stimulated lipolysis could be accurately estimated in vivo by simple clinical/biochemical measures and may be used to identify risk individuals for intensified preventive measures.
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Affiliation(s)
- Peter Arner
- Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm 141 86, Sweden.
| | - Daniel P Andersson
- Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm 141 86, Sweden
| | - Jesper Bäckdahl
- Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm 141 86, Sweden
| | - Ingrid Dahlman
- Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm 141 86, Sweden
| | - Mikael Rydén
- Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm 141 86, Sweden.
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17
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Lundbäck V, Kulyte A, Strawbridge RJ, Ryden M, Arner P, Marcus C, Dahlman I. FAM13A and POM121C are candidate genes for fasting insulin: functional follow-up analysis of a genome-wide association study. Diabetologia 2018; 61:1112-1123. [PMID: 29487953 PMCID: PMC6448992 DOI: 10.1007/s00125-018-4572-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/20/2017] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS By genome-wide association meta-analysis, 17 genetic loci associated with fasting serum insulin (FSI), a marker of systemic insulin resistance, have been identified. To define potential culprit genes in these loci, in a cross-sectional study we analysed white adipose tissue (WAT) expression of 120 genes in these loci in relation to systemic and adipose tissue variables, and functionally evaluated genes demonstrating genotype-specific expression in WAT (eQTLs). METHODS Abdominal subcutaneous adipose tissue biopsies were obtained from 114 women. Basal lipolytic activity was measured as glycerol release from adipose tissue explants. Adipocytes were isolated and insulin-stimulated incorporation of radiolabelled glucose into lipids was used to quantify adipocyte insulin sensitivity. Small interfering RNA-mediated knockout in human mesenchymal stem cells was used for functional evaluation of genes. RESULTS Adipose expression of 48 of the studied candidate genes associated significantly with FSI, whereas expression of 24, 17 and 2 genes, respectively, associated with adipocyte insulin sensitivity, lipolysis and/or WAT morphology (i.e. fat cell size relative to total body fat mass). Four genetic loci contained eQTLs. In one chromosome 4 locus (rs3822072), the FSI-increasing allele associated with lower FAM13A expression and FAM13A expression associated with a beneficial metabolic profile including decreased WAT lipolysis (regression coefficient, R = -0.50, p = 5.6 × 10-7). Knockdown of FAM13A increased lipolysis by ~1.5-fold and the expression of LIPE (encoding hormone-sensitive lipase, a rate-limiting enzyme in lipolysis). At the chromosome 7 locus (rs1167800), the FSI-increasing allele associated with lower POM121C expression. Consistent with an insulin-sensitising function, POM121C expression associated with systemic insulin sensitivity (R = -0.22, p = 2.0 × 10-2), adipocyte insulin sensitivity (R = 0.28, p = 3.4 × 10-3) and adipose hyperplasia (R = -0.29, p = 2.6 × 10-2). POM121C knockdown decreased expression of all adipocyte-specific markers by 25-50%, suggesting that POM121C is necessary for adipogenesis. CONCLUSIONS/INTERPRETATION Gene expression and adipocyte functional studies support the notion that FAM13A and POM121C control adipocyte lipolysis and adipogenesis, respectively, and might thereby be involved in genetic control of systemic insulin sensitivity.
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Affiliation(s)
- Veroniqa Lundbäck
- Department of Clinical Science, Intervention and Technology, Division of Paediatrics, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Agne Kulyte
- Department of Medicine, Huddinge, Karolinska Institutet, C2:94, SE-141 86, Stockholm, Sweden
| | - Rona J Strawbridge
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Department of Medicine, Solna, Karolinska Institute, Stockholm, Sweden
| | - Mikael Ryden
- Department of Medicine, Huddinge, Karolinska Institutet, C2:94, SE-141 86, Stockholm, Sweden
| | - Peter Arner
- Department of Medicine, Huddinge, Karolinska Institutet, C2:94, SE-141 86, Stockholm, Sweden
| | - Claude Marcus
- Department of Clinical Science, Intervention and Technology, Division of Paediatrics, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Ingrid Dahlman
- Department of Medicine, Huddinge, Karolinska Institutet, C2:94, SE-141 86, Stockholm, Sweden.
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18
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Small KS, Todorčević M, Civelek M, El-Sayed Moustafa JS, Wang X, Simon MM, Fernandez-Tajes J, Mahajan A, Horikoshi M, Hugill A, Glastonbury CA, Quaye L, Neville MJ, Sethi S, Yon M, Pan C, Che N, Viñuela A, Tsai PC, Nag A, Buil A, Thorleifsson G, Raghavan A, Ding Q, Morris AP, Bell JT, Thorsteinsdottir U, Stefansson K, Laakso M, Dahlman I, Arner P, Gloyn AL, Musunuru K, Lusis AJ, Cox R, Karpe F, McCarthy MI. Regulatory variants at KLF14 influence type 2 diabetes risk via a female-specific effect on adipocyte size and body composition. Nat Genet 2018; 50:572-580. [PMID: 29632379 PMCID: PMC5935235 DOI: 10.1038/s41588-018-0088-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 02/15/2018] [Indexed: 12/30/2022]
Abstract
Individual risk of type 2 diabetes (T2D) is modified by perturbations to the mass, distribution and function of adipose tissue. To investigate the mechanisms underlying these associations, we explored the molecular, cellular and whole-body effects of T2D-associated alleles near KLF14. We show that KLF14 diabetes-risk alleles act in adipose tissue to reduce KLF14 expression and modulate, in trans, the expression of 385 genes. We demonstrate, in human cellular studies, that reduced KLF14 expression increases pre-adipocyte proliferation but disrupts lipogenesis, and in mice, that adipose tissue-specific deletion of Klf14 partially recapitulates the human phenotype of insulin resistance, dyslipidemia and T2D. We show that carriers of the KLF14 T2D risk allele shift body fat from gynoid stores to abdominal stores and display a marked increase in adipocyte cell size, and that these effects on fat distribution, and the T2D association, are female specific. The metabolic risk associated with variation at this imprinted locus depends on the sex both of the subject and of the parent from whom the risk allele derives.
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Affiliation(s)
- Kerrin S. Small
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK,Corresponding authors: Correspondence should be addressed to K.S.S. () or M.I.M ()
| | - Marijana Todorčević
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Mete Civelek
- Center for Public Health Genomics, Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA,Department of Medicine, University of California, Los Angeles, California, USA
| | | | - Xiao Wang
- Cardiovascular Institute, Department of Medicine, Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michelle M. Simon
- Biocomputing, Medical Research Council Harwell Institute, Oxford, UK
| | | | - Anubha Mahajan
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Momoko Horikoshi
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Alison Hugill
- Genetics of type 2 diabetes, Medical Research Council Harwell Institute, Oxford, UK
| | - Craig A. Glastonbury
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Lydia Quaye
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Matt J. Neville
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK,Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Siddharth Sethi
- Biocomputing, Medical Research Council Harwell Institute, Oxford, UK
| | - Marianne Yon
- Genetics of type 2 diabetes, Medical Research Council Harwell Institute, Oxford, UK
| | - Calvin Pan
- Department of Human Genetics, University of California, Los Angeles, California, USA
| | - Nam Che
- Department of Medicine, University of California, Los Angeles, California, USA
| | - Ana Viñuela
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Pei-Chien Tsai
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Abhishek Nag
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Alfonso Buil
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | | | | | - Qiurong Ding
- CAS Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, PR China
| | - Andrew P. Morris
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK,Department of Biostatistics, University of Liverpool, Liverpool, UK
| | - Jordana T. Bell
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Unnur Thorsteinsdottir
- deCODE Genetics, Reykjavik, Iceland,Faculty of Medicine, University of Iceland, Reykjavik Iceland
| | - Kari Stefansson
- deCODE Genetics, Reykjavik, Iceland,Faculty of Medicine, University of Iceland, Reykjavik Iceland
| | - Markku Laakso
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Ingrid Dahlman
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Peter Arner
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Anna L. Gloyn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK,Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Kiran Musunuru
- Cardiovascular Institute, Department of Medicine, Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Aldons J. Lusis
- Department of Medicine, University of California, Los Angeles, California, USA,Department of Human Genetics, University of California, Los Angeles, California, USA,Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Roger Cox
- Genetics of type 2 diabetes, Medical Research Council Harwell Institute, Oxford, UK
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK,Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Mark I. McCarthy
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK,Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK,Corresponding authors: Correspondence should be addressed to K.S.S. () or M.I.M ()
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19
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Long Non-Coding RNAs Associated with Metabolic Traits in Human White Adipose Tissue. EBioMedicine 2018; 30:248-260. [PMID: 29580841 PMCID: PMC5952343 DOI: 10.1016/j.ebiom.2018.03.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 12/25/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) belong to a recently discovered class of molecules proposed to regulate various cellular processes. Here, we systematically analyzed their expression in human subcutaneous white adipose tissue (WAT) and found that a limited set was differentially expressed in obesity and/or the insulin resistant state. Two lncRNAs herein termed adipocyte-specific metabolic related lncRNAs, ASMER-1 and ASMER-2 were enriched in adipocytes and regulated by both obesity and insulin resistance. Knockdown of either ASMER-1 or ASMER-2 by antisense oligonucleotides in in vitro differentiated human adipocytes revealed that both genes regulated adipogenesis, lipid mobilization and adiponectin secretion. The observed effects could be attributed to crosstalk between ASMERs and genes within the master regulatory pathways for adipocyte function including PPARG and INSR. Altogether, our data demonstrate that lncRNAs are modulators of the metabolic and secretory functions in human fat cells and provide an emerging link between WAT and common metabolic conditions.
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Dahlman I, Ryden M, Arner P. Family history of diabetes is associated with enhanced adipose lipolysis: Evidence for the implication of epigenetic factors. DIABETES & METABOLISM 2018; 44:155-159. [DOI: 10.1016/j.diabet.2017.10.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 10/13/2017] [Accepted: 10/17/2017] [Indexed: 01/06/2023]
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Yan H, Pierce JR, Myers KB, Dubose KD, Dubis GS, Tanner CJ, Hickner RC. Exercise Effects on Adipose Tissue Postprandial Lipolysis and Blood Flow in Children. Med Sci Sports Exerc 2018; 50:1249-1257. [PMID: 29381651 DOI: 10.1249/mss.0000000000001566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Poor suppression of lipolysis and blunted increase in blood flow after meal ingestion in obese adults may indicate resistance to the antilipolytic action of insulin. Exercise may be used to normalize lipolytic responses to food intake by increasing insulin sensitivity. PURPOSE To determine if acute bouts of aerobic exercise and/or excise training alter lipolytic and blood flow responses to food intake in lean (LN) and obese (OB) children. METHODS Sixty-five children (9-11 yr) were randomized into acute exercise (EX: 16 LN and 28 OB) or control (CON: 9 LN and 12 OB) groups that exercised (EX), or rested (CON) between standardized breakfast and lunch. Microdialysis probes were inserted into the subcutaneous abdominal adipose tissue to monitor interstitial glycerol (lipolysis) and blood flow. Changes in interstitial glycerol and nutritive flow were calculated from dialysate samples before and after each meal. A subgroup (OB = 15 and LN = 9) from the acute exercise group underwent 16 wk of aerobic exercise training. RESULTS Poor suppression of lipolysis and a blunted increase in adipose tissue nutritive blood flow in response to breakfast was associated with BMI percentile (r = 0.3, P < 0.05). These responses were normalized at lunch in the OB in the EX (P < 0.05), but not in OB in the CON. Sixteen weeks of exercise training did not improve meal-induced blood flow and marginally altered the antilipolytic response to the two meals (P = 0.06). CONCLUSIONS Daily bouts of acute aerobic exercise should be used to improve the antilipolytic and nutritive blood flow response to a subsequent meal in obese children.
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Affiliation(s)
- Huimin Yan
- Human Performance Laboratory, East Carolina University, Greenville, NC.,East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC.,Center for Health Disparities, East Carolina University, Greenville, NC.,Department of Kinesiology, East Carolina University, Greenville, NC.,Department of Exercise and Health Sciences, University of Massachusetts Boston, Boston, MA
| | - Joseph R Pierce
- Human Performance Laboratory, East Carolina University, Greenville, NC.,Department of Kinesiology, East Carolina University, Greenville, NC
| | - Kimberly B Myers
- Department of Nutrition Science, East Carolina University, Greenville, NC
| | - Katrina D Dubose
- Department of Kinesiology, East Carolina University, Greenville, NC
| | - Gabriel S Dubis
- Human Performance Laboratory, East Carolina University, Greenville, NC.,East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC.,Department of Kinesiology, East Carolina University, Greenville, NC
| | - Charles J Tanner
- Human Performance Laboratory, East Carolina University, Greenville, NC.,East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC.,Department of Kinesiology, East Carolina University, Greenville, NC
| | - Robert C Hickner
- Human Performance Laboratory, East Carolina University, Greenville, NC.,East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC.,Center for Health Disparities, East Carolina University, Greenville, NC.,Department of Kinesiology, East Carolina University, Greenville, NC.,Department of Physiology, East Carolina University, Greenville, NC.,Discipline of Biokinetics, Exercise, and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal, Westville, SOUTH AFRICA.,Department of Nutrition, Food and Exercise Sciences, College of Human Sciences, Florida State University, Tallahassee, FL
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22
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Abstract
OBJECTIVE Although white adipose tissue mass and distribution correlates with cardiovascular disease, the fat cell-specific perturbations underlying this association are not known. We determined the relationship between adipocyte size and lipid metabolism with cardiovascular risk. DESIGN/SUBJECTS Adipocyte size as well as spontaneous (basal) and hormone-stimulated effects on adipocyte lipid metabolism (lipolysis and lipogenesis) were investigated in abdominal subcutaneous adipose tissue of 304 men and 775 women. Subjects were classified into five categories according to Adult Treatment Panel III (ATPIII) metabolic syndrome criteria. RESULTS Adipocyte size increased with increasing ATPIII score (P < 0.0001). For lipolysis, there was a gradual increase in basal and catecholamine-stimulated lipolysis and a decrease in insulin-mediated inhibition of stimulated lipolysis with ATPIII (P < 0.0001). In contrast, the lipolytic action of atrial natriuretic peptide was similar between ATPIII classes. Basal and insulin-stimulated lipogenesis decreased with increasing score (P < 0.0001). Circulating free fatty acid levels were 50% higher in the top risk category (4-5) compared with the lowest score (P < 0.0001). Fat cell size correlated positively with increasing ATPIII score and lipolysis but negatively with lipogenesis. All these differences were independent of age, sex and body weight status (P < 0.0001 to 0.02 after correction). When all functional measures were put together, maximum insulin-stimulated lipogenesis, insulin-antilipolytic sensitivity and basal lipolysis together explained about 20% in the variation of ATPIII in score. CONCLUSIONS Independently of sex, age and body weight status, a high cardiovascular risk score associates with increased circulating free fatty acid levels and hormone-specific alterations of lipolysis/lipogenesis in enlarged subcutaneous fat cells.
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Affiliation(s)
- M Rydén
- Department of Medicine (H7), C2-94, Karolinska Institutet at Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - P Arner
- Department of Medicine (H7), C2-94, Karolinska Institutet at Karolinska University Hospital, Huddinge, Stockholm, Sweden
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Epigenetic Regulation of PLIN 1 in Obese Women and its Relation to Lipolysis. Sci Rep 2017; 7:10152. [PMID: 28860604 PMCID: PMC5578955 DOI: 10.1038/s41598-017-09232-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 07/17/2017] [Indexed: 02/08/2023] Open
Abstract
Increased adipocyte lipolysis links obesity to insulin resistance. The lipid droplet coating-protein Perilipin participates in regulation of lipolysis and is implicated in obesity. In the present study we investigate epigenetic regulation of the PLIN1 gene by correlating PLIN1 CpG methylation to gene expression and lipolysis, and functionally evaluating PLIN1 promoter methylation. PLIN1 CpG methylation in adipocytes and gene expression in white adipose tissue (WAT) was quantified in two cohorts by array. Basal lipolysis in WAT explants and adipocytes was quantified by measuring glycerol release. CpG-methylation of the PLIN1 promoter in adipocytes from obese women was higher as compared to never-obese women. PLIN1 promoter methylation was inversely correlated with PLIN1 mRNA expression and the lipolytic activity. Human mesenchymal stem cells (hMSCs) differentiated in vitro into adipocytes and harboring methylated PLIN1 promoter displayed decreased reporter gene activity as compared to hMSCs harboring unmethylated promoter. Treatment of hMSCs differentiated in vitro into adipocytes with a DNA methyltransferase inhibitor increased levels of PLIN1 mRNA and protein. In conclusion, the PLIN1 gene is epigenetically regulated and promoter methylation is inversely correlated with basal lipolysis in women suggesting that epigenetic regulation of PLIN1 is important for increased adipocyte lipolysis in insulin resistance states.
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Marcondes RR, Maliqueo M, Fornes R, Benrick A, Hu M, Ivarsson N, Carlström M, Cushman SW, Stenkula KG, Maciel GAR, Stener-Victorin E. Exercise differentially affects metabolic functions and white adipose tissue in female letrozole- and dihydrotestosterone-induced mouse models of polycystic ovary syndrome. Mol Cell Endocrinol 2017; 448:66-76. [PMID: 28344042 DOI: 10.1016/j.mce.2017.03.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/22/2017] [Accepted: 03/23/2017] [Indexed: 12/11/2022]
Abstract
Here we hypothesized that exercise in dihydrotestosterone (DHT) or letrozole (LET)-induced polycystic ovary syndrome mouse models improves impaired insulin and glucose metabolism, adipose tissue morphology, and expression of genes related to adipogenesis, lipid metabolism, Notch pathway and browning in inguinal and mesenteric fat. DHT-exposed mice had increased body weight, increased number of large mesenteric adipocytes. LET-exposed mice displayed increased body weight and fat mass, decreased insulin sensitivity, increased frequency of small adipocytes and increased expression of genes related to lipolysis in mesenteric fat. In both models, exercise decreased fat mass and inguinal and mesenteric adipose tissue expression of Notch pathway genes, and restored altered mesenteric adipocytes morphology. In conclusion, exercise restored mesenteric adipocytes morphology in DHT- and LET-exposed mice, and insulin sensitivity and mesenteric expression of lipolysis-related genes in LET-exposed mice. Benefits could be explained by downregulation of Notch, and modulation of browning and lipolysis pathways in the adipose tissue.
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Affiliation(s)
- Rodrigo R Marcondes
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; Disciplina de Ginecologia, Laboratório de Ginecologia Estrutural e Molecular (LIM 58), Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Manuel Maliqueo
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; Endocrinology and Metabolism Laboratory, Department of Medicine, West Division, University of Chile, Santiago, Chile
| | - Romina Fornes
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Anna Benrick
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; School of Health and Education, University of Skövde, Skövde, Sweden
| | - Min Hu
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Niklas Ivarsson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Mattias Carlström
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Samuel W Cushman
- Experimental Diabetes, Metabolism, and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, USA
| | - Karin G Stenkula
- Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Gustavo A R Maciel
- Disciplina de Ginecologia, Laboratório de Ginecologia Estrutural e Molecular (LIM 58), Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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Dahlman I, Belarbi Y, Laurencikiene J, Pettersson AM, Arner P, Kulyté A. Comprehensive functional screening of miRNAs involved in fat cell insulin sensitivity among women. Am J Physiol Endocrinol Metab 2017; 312:E482-E494. [PMID: 28270439 DOI: 10.1152/ajpendo.00251.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 01/18/2017] [Accepted: 02/22/2017] [Indexed: 01/12/2023]
Abstract
The key pathological link between obesity and type 2 diabetes is insulin resistance, but the molecular mechanisms are not entirely identified. micro-RNAs (miRNA) are dysregulated in obesity and may contribute to insulin resistance. Our objective was to detect and functionally investigate miRNAs linked to insulin sensitivity in human subcutaneous white adipose tissue (scWAT). Subjects were selected based on the insulin-stimulated lipogenesis response of subcutaneous adipocytes. Global miRNA profiling was performed in abdominal scWAT of 18 obese insulin-resistance (OIR), 21 obese insulin-sensitive (OIS), and 9 lean women. miRNAs demonstrating differential expression between OIR and OIS women were overexpressed in human in vitro-differentiated adipocytes followed by assessment of lipogenesis and identification of miRNA targets by measuring mRNA/protein expression and 3'-untranslated region analysis. Eleven miRNAs displayed differential expression between OIR and OIS states. Overexpression of miR-143-3p and miR-652-3p increased insulin-stimulated lipogenesis in human in vitro differentiated adipocytes and directly or indirectly affected several genes/proteins involved in insulin signaling at transcriptional or posttranscriptional levels. Adipose expression of miR-143-3p and miR-652-3p was positively associated with insulin-stimulated lipogenesis in scWAT independent of body mass index. In conclusion, miR-143-3p and miR-652-3p are linked to scWAT insulin resistance independent of obesity and influence insulin-stimulated lipogenesis by interacting at different steps with insulin-signaling pathways.
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Affiliation(s)
- Ingrid Dahlman
- Lipid Laboratory, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Yasmina Belarbi
- Lipid Laboratory, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Jurga Laurencikiene
- Lipid Laboratory, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Annie M Pettersson
- Lipid Laboratory, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Peter Arner
- Lipid Laboratory, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Agné Kulyté
- Lipid Laboratory, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
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Kulyté A, Ehrlund A, Arner P, Dahlman I. Global transcriptome profiling identifies KLF15 and SLC25A10 as modifiers of adipocytes insulin sensitivity in obese women. PLoS One 2017; 12:e0178485. [PMID: 28570579 PMCID: PMC5453532 DOI: 10.1371/journal.pone.0178485] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/12/2017] [Indexed: 12/15/2022] Open
Abstract
Although the mechanisms linking obesity to insulin resistance (IR) and type 2 diabetes (T2D) are not entirely understood, it is likely that alterations of adipose tissue function are involved. The aim of this study was to identify new genes controlling insulin sensitivity in adipocytes from obese women with either insulin resistant (OIR) or sensitive (OIS) adipocytes. Insulin sensitivity was first determined by measuring lipogenesis in isolated adipocytes from abdominal subcutaneous white adipose tissue (WAT) in a large observational study. Lipogenesis was measured under conditions where glucose transport was the rate limiting step and reflects in vivo insulin sensitivity. We then performed microarray-based transcriptome profiling on subcutaneous WAT specimen from a subgroup of 9 lean, 21 OIS and 18 obese OIR women. We could identify 432 genes that were differentially expressed between the OIR and OIS group (FDR ≤5%). These genes are enriched in pathways related to glucose and amino acid metabolism, cellular respiration, and insulin signaling, and include genes such as SLC2A4, AKT2, as well as genes coding for enzymes in the mitochondria respiratory chain. Two IR-associated genes, KLF15 encoding a transcription factor and SLC25A10 encoding a dicarboxylate carrier, were selected for functional evaluation in adipocytes differentiated in vitro. Knockdown of KLF15 and SLC25A10 using siRNA inhibited insulin-stimulated lipogenesis in adipocytes. Transcriptome profiling of siRNA-treated cells suggested that KLF15 might control insulin sensitivity by influencing expression of PPARG, PXMP2, AQP7, LPL and genes in the mitochondrial respiratory chain. Knockdown of SLC25A10 had only modest impact on the transcriptome, suggesting that it might directly influence insulin sensitivity in adipocytes independently of transcription due to its important role in fatty acid synthesis. In summary, this study identifies novel genes associated with insulin sensitivity in adipocytes in women independently of obesity. KFL15 and SLC25A10 are inhibitors of insulin-stimulated lipogenesis under conditions when glucose transport is the rate limiting step.
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Affiliation(s)
- Agné Kulyté
- Lipid laboratory, Department of Medicine H7, Karolinska Institutet, Stockholm, Sweden
| | - Anna Ehrlund
- Lipid laboratory, Department of Medicine H7, Karolinska Institutet, Stockholm, Sweden
| | - Peter Arner
- Lipid laboratory, Department of Medicine H7, Karolinska Institutet, Stockholm, Sweden
| | - Ingrid Dahlman
- Lipid laboratory, Department of Medicine H7, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
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Giles ED, Steig AJ, Jackman MR, Higgins JA, Johnson GC, Lindstrom RC, MacLean PS. Exercise Decreases Lipogenic Gene Expression in Adipose Tissue and Alters Adipocyte Cellularity during Weight Regain After Weight Loss. Front Physiol 2016; 7:32. [PMID: 26903882 PMCID: PMC4748045 DOI: 10.3389/fphys.2016.00032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 01/25/2016] [Indexed: 12/15/2022] Open
Abstract
Exercise is a potent strategy to facilitate long-term weight maintenance. In addition to increasing energy expenditure and reducing appetite, exercise also favors the oxidation of dietary fat, which likely helps prevent weight re-gain. It is unclear whether this exercise-induced metabolic shift is due to changes in energy balance, or whether exercise imparts additional adaptations in the periphery that limit the storage and favor the oxidation of dietary fat. To answer this question, adipose tissue lipid metabolism and related gene expression were studied in obese rats following weight loss and during the first day of relapse to obesity. Mature, obese rats were weight-reduced for 2 weeks with or without daily treadmill exercise (EX). Rats were weight maintained for 6 weeks, followed by relapse on: (a) ad libitum low fat diet (LFD), (b) ad libitum LFD plus EX, or (c) a provision of LFD to match the positive energy imbalance of exercised, relapsing animals. 24 h retention of dietary- and de novo-derived fat were assessed directly using 14C palmitate/oleate and 3H20, respectively. Exercise decreased the size, but increased the number of adipocytes in both retroperitoneal (RP) and subcutaneous (SC) adipose depots, and prevented the relapse-induced increase in adipocyte size. Further, exercise decreased the expression of genes involved in lipid uptake (CD36 and LPL), de novo lipogenesis (FAS, ACC1), and triacylglycerol synthesis (MGAT and DGAT) in RP adipose during relapse following weight loss. This was consistent with the metabolic data, whereby exercise reduced retention of de novo-derived fat even when controlling for the positive energy imbalance. The decreased trafficking of dietary fat to adipose tissue with exercise was explained by reduced energy intake which attenuated energy imbalance during refeeding. Despite having decreased expression of lipogenic genes, the net retention of de novo-derived lipid was higher in both the RP and SC adipose of exercising animals compared to their energy gap-matched controls. Our interpretation of this data is that much of this lipid is being made by the liver and subsequently trafficked to adipose tissue storage. Together, these concerted effects may explain the beneficial effects of exercise on preventing weight regain following weight loss.
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Affiliation(s)
- Erin D Giles
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical CampusAurora, CO, USA; Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Colorado Anschutz Medical CampusAurora, CO, USA
| | - Amy J Steig
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical CampusAurora, CO, USA; Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Colorado Anschutz Medical CampusAurora, CO, USA
| | - Matthew R Jackman
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical CampusAurora, CO, USA; Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Colorado Anschutz Medical CampusAurora, CO, USA
| | - Janine A Higgins
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical CampusAurora, CO, USA; Department of Pediatrics, University of Colorado Anschutz Medical CampusAurora, CO, USA
| | - Ginger C Johnson
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical CampusAurora, CO, USA; Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Colorado Anschutz Medical CampusAurora, CO, USA
| | - Rachel C Lindstrom
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical CampusAurora, CO, USA; Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Colorado Anschutz Medical CampusAurora, CO, USA
| | - Paul S MacLean
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical CampusAurora, CO, USA; Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Colorado Anschutz Medical CampusAurora, CO, USA
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Dahlman I, Rydén M, Brodin D, Grallert H, Strawbridge RJ, Arner P. Numerous Genes in Loci Associated With Body Fat Distribution Are Linked to Adipose Function. Diabetes 2016; 65:433-7. [PMID: 26798124 DOI: 10.2337/db15-0828] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Central fat accumulation is a strong risk factor for type 2 diabetes. Genome-wide association studies have identified numerous loci associated with body fat distribution. The objectives of the current study are to examine whether genes in genetic loci linked to fat distribution can be linked to fat cell size and number (morphology) and/or adipose tissue function. We show, in a cohort of 114 women, that almost half of the 96 genes in these loci are indeed associated with abdominal subcutaneous adipose tissue parameters. Thus, adipose mRNA expression of the genes is strongly related to adipose morphology, catecholamine-induced lipid mobilization (lipolysis), or insulin-stimulated lipid synthesis in adipocytes (lipogenesis). In conclusion, the genetic influence on body fat distribution could be mediated via several specific alterations in adipose tissue morphology and function, which in turn may influence the development of type 2 diabetes.
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Affiliation(s)
- Ingrid Dahlman
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Mikael Rydén
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - David Brodin
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Harald Grallert
- German Center for Diabetes Research (DZD), Neuherberg, Germany Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Rona J Strawbridge
- Cardiovascular Genetics and Genomics Group, Atherosclerosis Research Unit, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
| | - Peter Arner
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
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Karbiener M, Glantschnig C, Pisani DF, Laurencikiene J, Dahlman I, Herzig S, Amri EZ, Scheideler M. Mesoderm-specific transcript (MEST) is a negative regulator of human adipocyte differentiation. Int J Obes (Lond) 2015; 39:1733-41. [PMID: 26119994 PMCID: PMC4625608 DOI: 10.1038/ijo.2015.121] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 06/09/2015] [Accepted: 06/22/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND A growing body of evidence suggests that many downstream pathologies of obesity are amplified or even initiated by molecular changes within the white adipose tissue (WAT). Such changes are the result of an excessive expansion of individual white adipocytes and could potentially be ameliorated via an increase in de novo adipocyte recruitment (adipogenesis). Mesoderm-specific transcript (MEST) is a protein with a putative yet unidentified enzymatic function and has previously been shown to correlate with adiposity and adipocyte size in mouse. OBJECTIVES This study analysed WAT samples and employed a cell model of adipogenesis to characterise MEST expression and function in human. METHODS AND RESULTS MEST mRNA and protein levels increased during adipocyte differentiation of human multipotent adipose-derived stem cells. Further, obese individuals displayed significantly higher MEST levels in WAT compared with normal-weight subjects, and MEST was significantly correlated with adipocyte volume. In striking contrast to previous mouse studies, knockdown of MEST enhanced human adipocyte differentiation, most likely via a significant promotion of peroxisome proliferator-activated receptor signalling, glycolysis and fatty acid biosynthesis pathways at early stages. Correspondingly, overexpression of MEST impaired adipogenesis. We further found that silencing of MEST fully substitutes for the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) as an inducer of adipogenesis. Accordingly, phosphorylation of the pro-adipogenic transcription factors cyclic AMP responsive element binding protein (CREB) and activating transcription factor 1 (ATF1) were highly increased on MEST knockdown. CONCLUSIONS Although we found a similar association between MEST and adiposity as previously described for mouse, our functional analyses suggest that MEST acts as an inhibitor of human adipogenesis, contrary to previous murine studies. We have further established a novel link between MEST and CREB/ATF1 that could be of general relevance in regulation of metabolism, in particular obesity-associated diseases.
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Affiliation(s)
- M Karbiener
- Department of Phoniatrics, ENT University Hospital, Medical University Graz, Graz, Austria
| | - C Glantschnig
- Institute for Diabetes and Cancer (IDC), Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Heidelberg University Hospital, Heidelberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - D F Pisani
- Université Nice Sophia Antipolis, iBV, UMR, Nice, France
- CNRS, iBV, UMR, Nice, France
- Inserm, iBV, Nice, France
| | - J Laurencikiene
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - I Dahlman
- Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - S Herzig
- Institute for Diabetes and Cancer (IDC), Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Heidelberg University Hospital, Heidelberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - E-Z Amri
- Université Nice Sophia Antipolis, iBV, UMR, Nice, France
- CNRS, iBV, UMR, Nice, France
- Inserm, iBV, Nice, France
| | - M Scheideler
- Institute for Diabetes and Cancer (IDC), Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Heidelberg University Hospital, Heidelberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
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30
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Arner P, Sinha I, Thorell A, Rydén M, Dahlman-Wright K, Dahlman I. The epigenetic signature of subcutaneous fat cells is linked to altered expression of genes implicated in lipid metabolism in obese women. Clin Epigenetics 2015; 7:93. [PMID: 26351548 PMCID: PMC4562340 DOI: 10.1186/s13148-015-0126-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/27/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Obesity is associated with changes in fat cell gene expression and metabolism. What drives these changes is not well understood. We aimed to explore fat cell epigenetics, i.e., DNA methylation, as one mediator of gene regulation, in obese women. The global DNA methylome for abdominal subcutaneous fat cells was compared between 15 obese case (BMI 41.4 ± 4.4 kg/m(2), mean ± SD) and 14 never-obese control women (BMI 25.2 ± 2.5 kg/m(2)). Global array-based transcriptome analysis was analyzed for subcutaneous white adipose tissue (WAT) from 11 obese and 9 never-obese women. Limma was used for statistical analysis. RESULTS We identified 5529 differentially methylated DNA sites (DMS) for 2223 differentially expressed genes between obese cases and never-obese controls (false discovery rate <5 %). The 5529 DMS displayed a median difference in beta value of 0.09 (range 0.01 to 0.40) between groups. DMS were under-represented in CpG islands and in promoter regions, and over-represented in open sea-regions and gene bodies. The 2223 differentially expressed genes with DMS were over-represented in key fat cell pathways: 31 of 130 (25 %) genes linked to "adipogenesis" (adjusted P = 1.66 × 10(-11)), 31 of 163 (19 %) genes linked to "insulin signaling" (adjusted P = 1.91 × 10(-9)), and 18 of 67 (27 %) of genes linked to "lipolysis" (P = 6.1 × 10(-5)). In most cases, gene expression and DMS displayed reciprocal changes in obese women. Furthermore, among 99 candidate genes in genetic loci associated with body fat distribution in genome-wide association studies (GWAS); 22 genes displayed differential expression accompanied by DMS in obese versus never-obese women (P = 0.0002), supporting the notion that a significant proportion of gene loci linked to fat distribution are epigenetically regulated. CONCLUSIONS Subcutaneous WAT from obese women is characterized by congruent changes in DNA methylation and expression of genes linked to generation, distribution, and metabolic function of fat cells. These alterations may contribute to obesity-associated metabolic disturbances such as insulin resistance in women.
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Affiliation(s)
- Peter Arner
- Lipid laboratory, Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, S-141 86 Sweden
| | - Indranil Sinha
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, S-141 83 Sweden
| | - Anders Thorell
- Department of Clinical Sciences, Danderyds Hospital, Karolinska Institutet, Stockholm, Sweden ; Department of Surgery, Ersta Hospital, Stockholm, Sweden
| | - Mikael Rydén
- Lipid laboratory, Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, S-141 86 Sweden
| | - Karin Dahlman-Wright
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, S-141 83 Sweden ; SciLifeLab, Science for Life Laboratory, S-171 65 Solna, Sweden
| | - Ingrid Dahlman
- Lipid laboratory, Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, S-141 86 Sweden
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Hartig SM, Bader DA, Abadie KV, Motamed M, Hamilton MP, Long W, York B, Mueller M, Wagner M, Trauner M, Chan L, Bajaj M, Moore DD, Mancini MA, McGuire SE. Ubc9 Impairs Activation of the Brown Fat Energy Metabolism Program in Human White Adipocytes. Mol Endocrinol 2015; 29:1320-33. [PMID: 26192107 DOI: 10.1210/me.2015-1084] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Insulin resistance and type 2 diabetes mellitus (T2DM) result from an inability to efficiently store and catabolize surplus energy in adipose tissue. Subcutaneous adipocytes protect against insulin resistance and T2DM by coupling differentiation with the induction of brown fat gene programs for efficient energy metabolism. Mechanisms that disrupt these programs in adipocytes are currently poorly defined, but represent therapeutic targets for the treatment of T2DM. To gain insight into these mechanisms, we performed a high-throughput microscopy screen that identified ubiquitin carrier protein 9 (Ubc9) as a negative regulator of energy storage in human sc adipocytes. Ubc9 depletion enhanced energy storage and induced the brown fat gene program in human sc adipocytes. Induction of adipocyte differentiation resulted in decreased Ubc9 expression commensurate with increased brown fat gene expression. Thiazolidinedione treatment reduced the interaction between Ubc9 and peroxisome proliferator-activated receptor (PPAR)γ, suggesting a mechanism by which Ubc9 represses PPARγ activity. In support of this hypothesis, Ubc9 overexpression remodeled energy metabolism in human sc adipocytes by selectively inhibiting brown adipocyte-specific function. Further, Ubc9 overexpression decreased uncoupling protein 1 expression by disrupting PPARγ binding at a critical uncoupling protein 1 enhancer region. Last, Ubc9 is significantly elevated in sc adipose tissue isolated from mouse models of insulin resistance as well as diabetic and insulin-resistant humans. Taken together, our findings demonstrate a critical role for Ubc9 in the regulation of sc adipocyte energy homeostasis.
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Affiliation(s)
- Sean M Hartig
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - David A Bader
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Kathleen V Abadie
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Massoud Motamed
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Mark P Hamilton
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Weiwen Long
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Brian York
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Michaela Mueller
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Martin Wagner
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Michael Trauner
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Lawrence Chan
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Mandeep Bajaj
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - David D Moore
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Michael A Mancini
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Sean E McGuire
- Department of Molecular and Cellular Biology (S.M.H., D.A.B., K.V.A., M.Mo., M.P.H., W.L., B.Y., L.C., D.D.M., M.A.M., S.E.M.), Baylor College of Medicine, Houston, Texas 77030; Department of Biochemistry and Molecular Biology (W.L.), Wright State University Boonshoft School of Medicine, Dayton, Ohio 45435; Hans Popper Laboratory of Molecular Hepatology (M.Mu., M.T.), Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Laboratory of Experimental Hepatology (M.W.), Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Diabetes and Endocrinology Research Center (L.C., M.B.), Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, and the Baylor St Luke's Medical Center, Houston, Texas 77030; and Division of Radiation Oncology (S.E.M.), The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
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The fat cell epigenetic signature in post-obese women is characterized by global hypomethylation and differential DNA methylation of adipogenesis genes. Int J Obes (Lond) 2015; 39:910-9. [PMID: 25783037 DOI: 10.1038/ijo.2015.31] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 02/16/2015] [Accepted: 02/22/2015] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES Obese subjects have increased number of enlarged fat cells that are reduced in size but not in number in post-obesity. We performed DNA methylation profiling in fat cells with the aim of identifying differentially methylated DNA sites (DMS) linked to adipose hyperplasia (many small fat cells) in post-obesity. SUBJECTS/METHODS Genome-wide DNA methylation was analyzed in abdominal subcutaneous fat cells from 16 women examined 2 years after gastric bypass surgery at a post-obese state (body mass index (BMI) 26±2 kg m(-2), mean±s.d.) and from 14 never-obese women (BMI 25±2 kg m(-2)). Gene expression was analyzed in subcutaneous adipose tissue from nine women in each group. In a secondary analysis, we examined DNA methylation and expression of adipogenesis genes in 15 and 11 obese women, respectively. RESULTS The average degree of DNA methylation of all analyzed CpG sites was lower in fat cells from post-obese as compared with never-obese women (P=0.014). A total of 8504 CpG sites were differentially methylated in fat cells from post-obese versus never-obese women (false discovery rate 1%). DMS were under-represented in CpG islands and surrounding shores. The 8504 DMS mapped to 3717 unique genes; these genes were over-represented in cell differentiation pathways. Notably, 27% of the genes linked to adipogenesis (that is, 35 of 130) displayed DMS (adjusted P=10(-8)) in post-obese versus never-obese women. Next, we explored DNA methylation and expression of genes linked to adipogenesis in more detail in adipose tissue samples. DMS annotated to adipogenesis genes were not accompanied by differential gene expression in post-obese compared with never-obese women. In contrast, adipogenesis genes displayed differential DNA methylation accompanied by altered expression in obese women. CONCLUSIONS Global CpG hypomethylation and over-representation of DMS in adipogenesis genes in fat cells may contribute to adipose hyperplasia in post-obese women.
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MacLean PS, Higgins JA, Giles ED, Sherk VD, Jackman MR. The role for adipose tissue in weight regain after weight loss. Obes Rev 2015; 16 Suppl 1:45-54. [PMID: 25614203 PMCID: PMC4371661 DOI: 10.1111/obr.12255] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Weight regain after weight loss is a substantial challenge in obesity therapeutics. Dieting leads to significant adaptations in the homeostatic system that controls body weight, which promotes overeating and the relapse to obesity. In this review, we focus specifically on the adaptations in white adipose tissues that contribute to the biological drive to regain weight after weight loss. Weight loss leads to a reduction in size of adipocytes and this decline in size alters their metabolic and inflammatory characteristics in a manner that facilitates the clearance and storage of ingested energy. We present the hypothesis whereby the long-term signals reflecting stored energy and short-term signals reflecting nutrient availability are derived from the cellularity characteristics of adipose tissues. These signals are received and integrated in the hypothalamus and hindbrain and an energy gap between appetite and metabolic requirements emerges and promotes a positive energy imbalance and weight regain. In this paradigm, the cellularity and metabolic characteristics of adipose tissues after energy-restricted weight loss could explain the persistence of a biological drive to regain weight during both weight maintenance and the dynamic period of weight regain.
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Affiliation(s)
- P S MacLean
- Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, Anschutz Health and Wellness Center, University of Colorado School of Medicine, Aurora, Colorado USA
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Kulyté A, Belarbi Y, Lorente-Cebrián S, Bambace C, Arner E, Daub CO, Hedén P, Rydén M, Mejhert N, Arner P. Additive effects of microRNAs and transcription factors on CCL2 production in human white adipose tissue. Diabetes 2014; 63:1248-58. [PMID: 24379347 DOI: 10.2337/db13-0702] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Adipose tissue inflammation is present in insulin-resistant conditions. We recently proposed a network of microRNAs (miRNAs) and transcription factors (TFs) regulating the production of the proinflammatory chemokine (C-C motif) ligand-2 (CCL2) in adipose tissue. We presently extended and further validated this network and investigated if the circuits controlling CCL2 can interact in human adipocytes and macrophages. The updated subnetwork predicted that miR-126/-193b/-92a control CCL2 production by several TFs, including v-ets erythroblastosis virus E26 oncogene homolog 1 (avian) (ETS1), MYC-associated factor X (MAX), and specificity protein 12 (SP1). This was confirmed in human adipocytes by the observation that gene silencing of ETS1, MAX, or SP1 attenuated CCL2 production. Combined gene silencing of ETS1 and MAX resulted in an additive reduction in CCL2 production. Moreover, overexpression of miR-126/-193b/-92a in different pairwise combinations reduced CCL2 secretion more efficiently than either miRNA alone. However, although effects on CCL2 secretion by co-overexpression of miR-92a/-193b and miR-92a/-126 were additive in adipocytes, the combination of miR-126/-193b was primarily additive in macrophages. Signals for miR-92a and -193b converged on the nuclear factor-κB pathway. In conclusion, TF and miRNA-mediated regulation of CCL2 production is additive and partly relayed by cell-specific networks in human adipose tissue that may be important for the development of insulin resistance/type 2 diabetes.
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Affiliation(s)
- Agné Kulyté
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
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Archer A, Laurencikiene J, Ahmed O, Steffensen KR, Parini P, Gustafsson JÅ, Korach-André M. Skeletal muscle as a target of LXR agonist after long-term treatment: focus on lipid homeostasis. Am J Physiol Endocrinol Metab 2014; 306:E494-502. [PMID: 24368671 DOI: 10.1152/ajpendo.00410.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The liver X receptors (LXR)α and LXRβ are transcription factors belonging to the nuclear receptor family, which play a central role in metabolic homeostasis, being master regulators of key target genes in the glucose and lipid pathways. Wild-type (WT), LXRα(-/-), and LXRβ(-/-) mice were fed a chow diet with (treated) or without (control) the synthetic dual LXR agonist GW3965 for 5 wk. GW3965 raised intrahepatic triglyceride (TG) level but, surprisingly, reduced serum TG level through the activation of serum lipase activity. The serum TG reduction was associated with a repression of both catecholamine-stimulated lipolysis and relative glucose incorporation into lipid in isolated adipocytes through activation of LXRβ. We also demonstrated that LXRα is required for basal (nonstimulated) adipocyte metabolism, whereas LXRβ acts as a repressor of lipolysis. On the contrary, in skeletal muscle (SM), the lipogenic and cholesterol transporter LXR target genes were markedly induced in WT and LXRα(-/-) mice and to a lesser extent in LXRβ(-/-) mice following treatment with GW3965. Moreover, TG content was reduced in SM of LXRβ(-/-) mice, associated with increased expression of the main TG-lipase genes Hsl and Atgl. Energy expenditure was increased, and a switch from glucose to lipid oxidation was observed. In conclusion, we provide evidence that LXR might be an essential regulator of the lipid balance between tissues to ensure appropriate control of the flux of fuel. Importantly, we show that, after chronic treatment with GW3965, SM becomes the target tissue for LXR activation, as opposed to liver, in acute treatment.
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Affiliation(s)
- Amena Archer
- Department of Biosciences and Nutrition and Center for Biosciences at NOVUM, Karolinska Institute, Huddinge, Sweden
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Kulyté A, Lorente-Cebrián S, Gao H, Mejhert N, Agustsson T, Arner P, Rydén M, Dahlman I. MicroRNA profiling links miR-378 to enhanced adipocyte lipolysis in human cancer cachexia. Am J Physiol Endocrinol Metab 2014; 306:E267-74. [PMID: 24326420 DOI: 10.1152/ajpendo.00249.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cancer cachexia is associated with pronounced adipose tissue loss due to, at least in part, increased fat cell lipolysis. MicroRNAs (miRNAs) have recently been implicated in controlling several aspects of adipocyte function. To gain insight into the possible impact of miRNAs on adipose lipolysis in cancer cachexia, global miRNA expression was explored in abdominal subcutaneous adipose tissue from gastrointestinal cancer patients with (n = 10) or without (n = 11) cachexia. Effects of miRNA overexpression or inhibition on lipolysis were determined in human in vitro differentiated adipocytes. Out of 116 miRNAs present in adipose tissue, five displayed distinct cachexia-associated expression according to both microarray and RT-qPCR. Four (miR-483-5p/-23a/-744/-99b) were downregulated, whereas one (miR-378) was significantly upregulated in cachexia. Adipose expression of miR-378 associated strongly and positively with catecholamine-stimulated lipolysis in adipocytes. This correlation is most probably causal because overexpression of miR-378 in human adipocytes increased catecholamine-stimulated lipolysis. In addition, inhibition of miR-378 expression attenuated stimulated lipolysis and reduced the expression of LIPE, PLIN1, and PNPLA2, a set of genes encoding key lipolytic regulators. Taken together, increased miR-378 expression could play an etiological role in cancer cachexia-associated adipose tissue loss via effects on adipocyte lipolysis.
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Affiliation(s)
- Agné Kulyté
- Lipid Laboratory, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
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Jiang LQ, Franck N, Egan B, Sjögren RJO, Katayama M, Duque-Guimaraes D, Arner P, Zierath JR, Krook A. Autocrine role of interleukin-13 on skeletal muscle glucose metabolism in type 2 diabetic patients involves microRNA let-7. Am J Physiol Endocrinol Metab 2013; 305:E1359-66. [PMID: 24105413 DOI: 10.1152/ajpendo.00236.2013] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Low-grade inflammation associated with type 2 diabetes (T2DM) is postulated to exacerbate insulin resistance. We report that serum levels, as well as IL-13 secreted from cultured skeletal muscle, are reduced in T2DM vs. normal glucose-tolerant (NGT) subjects. IL-13 exposure increases skeletal muscle glucose uptake, oxidation, and glycogen synthesis via an Akt-dependent mechanism. Expression of microRNA let-7a and let-7d, which are direct translational repressors of the IL-13 gene, was increased in skeletal muscle from T2DM patients. Overexpression of let-7a and let-7d in cultured myotubes reduced IL-13 secretion. Furthermore, basal glycogen synthesis was reduced in cultured myotubes exposed to an IL-13-neutralizing antibody. Thus, IL-13 is synthesized and released by skeletal muscle through a mechanism involving let-7, and this effect is attenuated in skeletal muscle from insulin-resistant T2DM patients. In conclusion, IL-13 plays an autocrine role in skeletal muscle to increase glucose uptake and metabolism, suggesting a role in glucose homeostasis in metabolic disease.
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Affiliation(s)
- Lake Q Jiang
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
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Company JM, Roberts MD, Toedebusch RG, Cruthirds CL, Booth FW. Sudden decrease in physical activity evokes adipocyte hyperplasia in 70- to 77-day-old rats but not 49- to 56-day-old rats. Am J Physiol Regul Integr Comp Physiol 2013; 305:R1465-78. [PMID: 24089381 DOI: 10.1152/ajpregu.00139.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cessation of physical activity in rodents and humans initiates obesogenic mechanisms. The overall purpose of the current study was to determine how the cessation of daily physical activity in rats at 49-56 days of age and at 70-77 days of age via wheel lock (WL) affects adipose tissue characteristics. Male Wistar rats began voluntary running at 28 days old and were either killed at 49-56 days old or at 70-77 days old. Two cohorts of rats always had wheel access (RUN), a second two cohorts of rats had wheel access restricted during the last 7 days (7d-WL), and a third two cohorts of rats did not have access to a voluntary running wheel after the first 6 days of (SED). We observed more robust changes with WL in the 70- to 77-day-old rats. Compared with RUN rats, 7d-WL rats exhibited greater rates of gain in fat mass and percent body fat, increased adipocyte number, higher percentage of small adipocytes, and greater cyclin A1 mRNA in epididymal and perirenal adipose tissue. In contrast, 49- to 56-day-old rats had no change in most of the same characteristics. There was no increase in inflammatory mRNA expression in either cohort with WL. These findings suggest that adipose tissue in 70- to 77-day-old rats is more protected from WL than 49- to 56-day-old rats and responds by expansion via hyperplasia.
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Affiliation(s)
- Joseph M Company
- Department of Biomedical Science, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
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Mejhert N, Wilfling F, Esteve D, Galitzky J, Pellegrinelli V, Kolditz CI, Viguerie N, Tordjman J, Näslund E, Trayhurn P, Lacasa D, Dahlman I, Stich V, Lång P, Langin D, Bouloumié A, Clément K, Rydén M. Semaphorin 3C is a novel adipokine linked to extracellular matrix composition. Diabetologia 2013; 56:1792-801. [PMID: 23666167 DOI: 10.1007/s00125-013-2931-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 04/18/2013] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS Alterations in white adipose tissue (WAT) function, including changes in protein (adipokine) secretion and extracellular matrix (ECM) composition, promote an insulin-resistant state. We set out to identify novel adipokines regulated by body fat mass in human subcutaneous WAT with potential roles in adipose function. METHODS Adipose transcriptome data and secretome profiles from conditions with increased/decreased WAT mass were combined. WAT donors were predominantly women. In vitro effects were assessed using recombinant protein. Results were confirmed by quantitative PCR/ELISA, metabolic assays and immunochemistry in human WAT and adipocytes. RESULTS We identified a hitherto uncharacterised adipokine, semaphorin 3C (SEMA3C), the expression of which correlated significantly with body weight, insulin resistance (HOMA of insulin resistance [HOMAIR], and the rate constant for the insulin tolerance test [KITT]) and adipose tissue morphology (hypertrophy vs hyperplasia). SEMA3C was primarily found in mature adipocytes and had no direct effect on human adipocyte differentiation, lipolysis, glucose transport or the expression of β-oxidation genes. This could in part be explained by the significant downregulation of its cognate receptors during adipogenesis. In contrast, in pre-adipocytes, SEMA3C increased the production/secretion of several ECM components (fibronectin, elastin and collagen I) and matricellular factors (connective tissue growth factor, IL6 and transforming growth factor-β1). Furthermore, the expression of SEMA3C in human WAT correlated positively with the degree of fibrosis in WAT. CONCLUSIONS/INTERPRETATION SEMA3C is a novel adipokine regulated by weight changes. The correlation with WAT hypertrophy and fibrosis in vivo, as well as its effects on ECM production in human pre-adipocytes in vitro, together suggest that SEMA3C constitutes an adipocyte-derived paracrine signal that influences ECM composition and may play a pathophysiological role in human WAT.
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Affiliation(s)
- N Mejhert
- Department of Medicine, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden.
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Rydén M, Andersson DP, Bernard S, Spalding K, Arner P. Adipocyte triglyceride turnover and lipolysis in lean and overweight subjects. J Lipid Res 2013; 54:2909-13. [PMID: 23899442 DOI: 10.1194/jlr.m040345] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human obesity is associated with decreased triglyceride turnover and impaired lipolysis in adipocytes. We determined whether such defects also occur in subjects with only moderate increase in fat mass. Human abdominal subcutaneous adipose tissue was investigated in healthy, nonobese subjects [body mass index (BMI) > 17 kg/m(2) and BMI < 30 kg/m(2)]. Triglyceride age, reflecting lipid turnover, was examined in 41 subjects by assessing the incorporation of atmospheric (14)C into adipose lipids. Adipocyte lipolysis was examined as the ability of lipolytic agents to stimulate glycerol release in 333 subjects. Adipocyte triglyceride age was markedly increased in overweight (BMI ≥ 25 kg/m(2)) compared with lean subjects (P = 0.017) with triglyceride T1/2 of 14 and 9 months, respectively (P = 0.04). Triglyceride age correlated positively with BMI (P = 0.002) but not with adipocyte volume (P = 0.2). Noradrenaline-, isoprenaline- or dibutyryl cyclic AMP-induced lipolysis was inversely correlated with triglyceride age (P < 0.01) and BMI (P < 0.0001) independently of basal lipolysis, gender, and nicotine use. Current, but not the highest or lowest BMI in adult life, correlated significantly (inversely) with lipolysis. In conclusion, adipocyte triglyceride turnover and lipolytic activity are decreased in overweight subjects and reflect the current BMI status. These changes may confer an increased risk for early development and/or maintenance of excess body fat.
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Affiliation(s)
- Mikael Rydén
- Department of Medicine Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
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41
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Jenkins NT, Padilla J, Rector RS, Laughlin MH. Influence of regular physical activity and caloric restriction on β-adrenergic and natriuretic peptide receptor expression in retroperitoneal adipose tissue of OLETF rats. Exp Physiol 2013; 98:1576-84. [PMID: 23833052 DOI: 10.1113/expphysiol.2013.074658] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The mechanisms underlying exercise-induced increases in adipose tissue blood flow and lipolysis involve both β-adrenergic receptor (βAR)- and natriuretic peptide receptor (NPR)-dependent processes. We hypothesized that daily wheel running (RUN) would increase the expression of NPR1, NPR2, βAR2 and βAR3 in retroperitoneal (RP) and epididymal (EPI) adipose tissues of obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Four-week-old OLETF rats were assigned to sedentary (SED, n = 6), calorie-restricted (CR, n = 8; fed 70% of SED) or RUN groups (n = 8). Rats were killed at 40 weeks of age. By design, body weight and adiposity were similar between RUN and CR animals, but each was lower than SED (P < 0.01). Compared with SED, RP depots of RUN rats exhibited 1.7- to 3.2-fold greater NPR1, NPR2, βAR2 and βAR3 mRNA levels (all P < 0.05). There were no differences between CR and SED in the expression of these genes in RP adipose tissues, and there were no differences in gene expression among groups in EPI adipose tissues. At the protein level, βAR2 and βAR3 were elevated in RUN and CR groups relative to the SED group in RP adipose tissues. In order to gain insight into the mechanisms underlying the activity-induced increases in NPR and βAR mRNAs, RP adipose tissue explants from Wistar rats were treated with atrial natriuretic peptide (ANP), adrenaline and/or S-nitroso-N-acetyl-dl-penicillamine (SNAP; a nitric oxide donor) in organ culture experiments. SNAP synergistically enhanced adrenaline- and ANP-stimulated increases in NPR2 and βAR2 mRNA levels. Our data suggest that physical activity-induced increases in nitric oxide interact with adrenaline and ANP to trigger the induction of NPR and βAR mRNAs in the RP adipose tissue depot of the OLETF rat.
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Affiliation(s)
- Nathan T Jenkins
- N. T. Jenkins: Department of Kinesiology, 115M Ramsey Center, 330 River Rd, University of Georgia, Athens, GA, 30605, USA.
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Bambace C, Dahlman I, Arner P, Kulyté A. NPC1 in human white adipose tissue and obesity. BMC Endocr Disord 2013; 13:5. [PMID: 23360456 PMCID: PMC3566954 DOI: 10.1186/1472-6823-13-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 01/24/2013] [Indexed: 11/19/2022] Open
Abstract
UNLABELLED BACKGROUND Genetic studies have implicated the NPC1 gene (Niemann Pick type C1) in susceptibility to obesity. METHODS To assess the potential function of NPC1 in obesity, we determined its expression in abdominal white adipose tissue (WAT) in relation to obesity. NPC1 mRNA was measured by RT-qPCR in lean and obese individuals, paired samples of subcutaneous (sc) and omental (om) WAT, before and after weight loss, in isolated adipocytes and intact adipose pieces, and in primary adipocyte cultures during adipocyte differentiation. NPC1 protein was examined in isolated adipocytes. RESULTS NPC1 mRNA was significantly increased in obese individuals in scWAT and omWAT and downregulated by weight loss. NPC1 mRNA was enriched in isolated fat cells of WAT, in scWAT versus omWAT but not modified during adipocyte differentiation. NPC1 protein mirrored expression of mRNA in lean and obese individuals. CONCLUSIONS NPC1 is highly expressed in human WAT adipocytes with increased levels in obese. These results suggest that NPC1 may play a role in adipocyte processes underlying obesity.
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Affiliation(s)
- Clara Bambace
- Department of Medicine Huddinge, Lipid Laboratory, Karolinska Institutet, 141 86, Stockholm, Sweden
| | - Ingrid Dahlman
- Department of Medicine Huddinge, Lipid Laboratory, Karolinska Institutet, 141 86, Stockholm, Sweden
| | - Peter Arner
- Department of Medicine Huddinge, Lipid Laboratory, Karolinska Institutet, 141 86, Stockholm, Sweden
| | - Agné Kulyté
- Department of Medicine Huddinge, Lipid Laboratory, Karolinska Institutet, 141 86, Stockholm, Sweden
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Moisa SS, Nozdrachev AD. One-time injection of calcitonin induces glucose intolerance in children with the first degree obesity. Health (London) 2013. [DOI: 10.4236/health.2013.56a1002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Arner E, Mejhert N, Kulyté A, Balwierz PJ, Pachkov M, Cormont M, Lorente-Cebrián S, Ehrlund A, Laurencikiene J, Hedén P, Dahlman-Wright K, Tanti JF, Hayashizaki Y, Rydén M, Dahlman I, van Nimwegen E, Daub CO, Arner P. Adipose tissue microRNAs as regulators of CCL2 production in human obesity. Diabetes 2012; 61:1986-93. [PMID: 22688341 PMCID: PMC3402332 DOI: 10.2337/db11-1508] [Citation(s) in RCA: 229] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In obesity, white adipose tissue (WAT) inflammation is linked to insulin resistance. Increased adipocyte chemokine (C-C motif) ligand 2 (CCL2) secretion may initiate adipose inflammation by attracting the migration of inflammatory cells into the tissue. Using an unbiased approach, we identified adipose microRNAs (miRNAs) that are dysregulated in human obesity and assessed their possible role in controlling CCL2 production. In subcutaneous WAT obtained from 56 subjects, 11 miRNAs were present in all subjects and downregulated in obesity. Of these, 10 affected adipocyte CCL2 secretion in vitro and for 2 miRNAs (miR-126 and miR-193b), regulatory circuits were defined. While miR-126 bound directly to the 3'-untranslated region of CCL2 mRNA, miR-193b regulated CCL2 production indirectly through a network of transcription factors, many of which have been identified in other inflammatory conditions. In addition, overexpression of miR-193b and miR-126 in a human monocyte/macrophage cell line attenuated CCL2 production. The levels of the two miRNAs in subcutaneous WAT were significantly associated with CCL2 secretion (miR-193b) and expression of integrin, α-X, an inflammatory macrophage marker (miR-193b and miR-126). Taken together, our data suggest that miRNAs may be important regulators of adipose inflammation through their effects on CCL2 release from human adipocytes and macrophages.
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Affiliation(s)
- Erik Arner
- RIKEN Omics Science Center, RIKEN Yokohama Institute, Yokohama, Kanagawa, Japan
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Niklas Mejhert
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Agné Kulyté
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Piotr J. Balwierz
- Biozentrum, University of Basel, and Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Mikhail Pachkov
- Biozentrum, University of Basel, and Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Mireille Cormont
- INSERM U895, Mediterranean Center of Molecular Medicine, Team 7 Molecular and Cellular Physiopathology of Obesity and Diabetes, Nice, France
- Faculty of Medicine, University of Nice Sophia-Antipolis, Nice, France
| | - Silvia Lorente-Cebrián
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Anna Ehrlund
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Jurga Laurencikiene
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | | | - Karin Dahlman-Wright
- Department of Biosciences and Nutrition, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Jean-François Tanti
- INSERM U895, Mediterranean Center of Molecular Medicine, Team 7 Molecular and Cellular Physiopathology of Obesity and Diabetes, Nice, France
- Faculty of Medicine, University of Nice Sophia-Antipolis, Nice, France
| | | | - Mikael Rydén
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Ingrid Dahlman
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Erik van Nimwegen
- Biozentrum, University of Basel, and Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Carsten O. Daub
- RIKEN Omics Science Center, RIKEN Yokohama Institute, Yokohama, Kanagawa, Japan
- Corresponding authors: Peter Arner (experimental and clinical correspondence), , and Carsten O. Daub (computational correspondence),
| | - Peter Arner
- Department of Medicine, Huddinge, Lipid Laboratory, Karolinska Institutet, Stockholm, Sweden
- Corresponding authors: Peter Arner (experimental and clinical correspondence), , and Carsten O. Daub (computational correspondence),
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Abstract
Hypocaloric diet is a key component of the weight-reducing treatment of obesity and obesity-related disorders. Hypocaloric diets and the associated weight reduction promote improvement of metabolic profile of obese individuals. Among the mechanisms that underlie this beneficial metabolic outcome, the diet-induced modifications of morphological and functional characteristics of human adipose tissue (AT) are believed to have an important role. Prospective studies of hypocaloric weight-reducing dietary intervention demonstrate effects on adipocyte metabolism, namely lipolysis and lipogenesis, and associated changes of the adipocyte size. The endocrine function of AT, which involves cytokine and adipokine production by adipocytes, as well as by cells of stromavascular fraction, is also regulated by dietary intervention. Related inflammatory status of AT is modulated also as a consequence of the changes in recruitment of immune cells, mainly macrophages, in AT. Here, we give an overview of metabolic and endocrine modifications in human AT induced by a variety of hypocaloric diets.
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Thompson D, Karpe F, Lafontan M, Frayn K. Physical activity and exercise in the regulation of human adipose tissue physiology. Physiol Rev 2012; 92:157-91. [PMID: 22298655 DOI: 10.1152/physrev.00012.2011] [Citation(s) in RCA: 204] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Physical activity and exercise are key components of energy expenditure and therefore of energy balance. Changes in energy balance alter fat mass. It is therefore reasonable to ask: What are the links between physical activity and adipose tissue function? There are many complexities. Physical activity is a multifaceted behavior of which exercise is just one component. Physical activity influences adipose tissue both acutely and in the longer term. A single bout of exercise stimulates adipose tissue blood flow and fat mobilization, resulting in delivery of fatty acids to skeletal muscles at a rate well-matched to metabolic requirements, except perhaps in vigorous intensity exercise. The stimuli include adrenergic and other circulating factors. There is a period following an exercise bout when fatty acids are directed away from adipose tissue to other tissues such as skeletal muscle, reducing dietary fat storage in adipose. With chronic exercise (training), there are changes in adipose tissue physiology, particularly an enhanced fat mobilization during acute exercise. It is difficult, however, to distinguish chronic "structural" changes from those associated with the last exercise bout. In addition, it is difficult to distinguish between the effects of training per se and negative energy balance. Epidemiological observations support the idea that physically active people have relatively low fat mass, and intervention studies tend to show that exercise training reduces fat mass. A much-discussed effect of exercise versus calorie restriction in preferentially reducing visceral fat is not borne out by meta-analyses. We conclude that, in addition to the regulation of fat mass, physical activity may contribute to metabolic health through beneficial dynamic changes within adipose tissue in response to each activity bout.
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Kulyté A, Rydén M, Mejhert N, Dungner E, Sjölin E, Arner P, Dahlman I. MTCH2 in human white adipose tissue and obesity. J Clin Endocrinol Metab 2011; 96:E1661-5. [PMID: 21795451 DOI: 10.1210/jc.2010-3050] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Genome-wide association studies have identified single-nucleotide polymorphisms in approximately 40 loci associated with obesity-related traits. How these loci regulate obesity is largely unknown. One obesity-associated single-nucleotide polymorphism is close to the MTCH2 gene (mitochondrial carrier homolog 2). OBJECTIVE The objective of the study was to assess the expression of genes in obesity-associated loci in abdominal sc white adipose tissue (scWAT) in relation to obesity. A more comprehensive expression study was performed on MTCH2. DESIGN mRNA levels of 66 genes from 40 loci were determined by microarray in scWAT from lean and obese women (n = 30). MTCH2 mRNA was measured by quantitative RT-PCR in lean and obese before and after weight loss in intact adipose pieces and isolated adipocytes, paired samples of scWAT and omental WAT, and primary adipocyte cultures (n = 191 subjects in total). MTCH2 genotypes were compared with mRNA expression in 96 women. MTCH2 protein was examined in scWAT of 38 individuals. RESULTS Adipose expression of eight genes was significantly associated with obesity; of these, MTCH2 displayed the highest absolute signal. MTCH2 mRNA and protein expression was significantly increased in obese women but was not affected by weight loss. MTCH2 was enriched in isolated fat cells and increased during adipocyte differentiation. There was no cis influence of MTCH2 genotypes on mRNA levels. CONCLUSION MTCH2 is highly expressed in human WAT and adipocytes with increased levels in obese women. These results suggest that MTCH2 may play a role in cellular processes underlying obesity.
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Affiliation(s)
- Agné Kulyté
- Department of Medicine, Huddinge, Lipid Laboratory, Novum, Karolinska Institutet, 141 86 Stockholm, Sweden.
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48
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Moisa SS, Nozdrachev AD. Disturbances of carbohydrate metabolism and factors stimulating its development in ontogenesis. ADVANCES IN GERONTOLOGY 2011. [DOI: 10.1134/s2079057011040114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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49
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Maclean PS, Bergouignan A, Cornier MA, Jackman MR. Biology's response to dieting: the impetus for weight regain. Am J Physiol Regul Integr Comp Physiol 2011; 301:R581-600. [PMID: 21677272 PMCID: PMC3174765 DOI: 10.1152/ajpregu.00755.2010] [Citation(s) in RCA: 262] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 06/08/2011] [Indexed: 01/02/2023]
Abstract
Dieting is the most common approach to losing weight for the majority of obese and overweight individuals. Restricting intake leads to weight loss in the short term, but, by itself, dieting has a relatively poor success rate for long-term weight reduction. Most obese people eventually regain the weight they have worked so hard to lose. Weight regain has emerged as one of the most significant obstacles for obesity therapeutics, undoubtedly perpetuating the epidemic of excess weight that now affects more than 60% of U.S. adults. In this review, we summarize the evidence of biology's role in the problem of weight regain. Biology's impact is first placed in context with other pressures known to affect body weight. Then, the biological adaptations to an energy-restricted, low-fat diet that are known to occur in the overweight and obese are reviewed, and an integrative picture of energy homeostasis after long-term weight reduction and during weight regain is presented. Finally, a novel model is proposed to explain the persistence of the "energy depletion" signal during the dynamic metabolic state of weight regain, when traditional adiposity signals no longer reflect stored energy in the periphery. The preponderance of evidence would suggest that the biological response to weight loss involves comprehensive, persistent, and redundant adaptations in energy homeostasis and that these adaptations underlie the high recidivism rate in obesity therapeutics. To be successful in the long term, our strategies for preventing weight regain may need to be just as comprehensive, persistent, and redundant, as the biological adaptations they are attempting to counter.
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Affiliation(s)
- Paul S Maclean
- University of Colorado Anschutz Medical Campus, Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, Center for Human Nutrition, Denver, Colorado, USA.
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50
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Dahlman I, Arner P. Genetics of adipose tissue biology. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 94:39-74. [PMID: 21036322 DOI: 10.1016/b978-0-12-375003-7.00003-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Adipose tissue morphology and release of free fatty acids, as well as peptide hormones, are believed to contribute to obesity and related metabolic disorders. These adipose tissue phenotypes are influenced by adiposity, but there is also a strong hereditary impact. Polymorphisms in numerous adipose-expressed genes have been evaluated for association with adipocyte and clinical phenotypes. In our opinion, some results are convincing. Thus ADRB2 and GPR74 genes are associated with adipocyte lipolysis, GPR74 also with BMI; PPARG and SREBP1, which promote adipogenesis and lipid storage, are associated with T2D and possible adiposity; ADIPOQ and ARL15 are associated with circulating levels of adiponectin, ARL15 also with coronary heart disease. We anticipate that the use of complementary approaches such as expression profiling and RNAi screening, and studies of additional levels of gene regulation, that is, miRNA and epigenetics, will be important to unravel the genetics of adipose tissue function.
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