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Lee Y, Hu S, Park YK, Lee JY. Health Benefits of Carotenoids: A Role of Carotenoids in the Prevention of Non-Alcoholic Fatty Liver Disease. Prev Nutr Food Sci 2019; 24:103-113. [PMID: 31328113 PMCID: PMC6615349 DOI: 10.3746/pnf.2019.24.2.103] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 04/02/2019] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases with a prevalence of ~25% worldwide. NAFLD includes simple hepatic steatosis, non-alcoholic steatohepatitis, fibrosis, and cirrhosis, which can further progress to hepatocellular carcinoma. Therefore, effective strategies for the prevention of NAFLD are needed. The pathogenesis of NAFLD is complicated due to diverse injury insults, such as fat accumulation, oxidative stress, inflammation, lipotoxicity, and apoptosis, which may act synergistically. Studies have shown that carotenoids, a natural group of isoprenoid pigments, prevent the development of NAFLD by exerting antioxidant, lipid-lowering, anti-inflammatory, anti-fibrotic, and insulin-sensitizing properties. This review summarizes the protective action of carotenoids, with primary focuses on astaxanthin, lycopene, β-carotene, β-cryptoxanthin, lutein, fucoxanthin, and crocetin, against the development and progression of NAFLD.
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Affiliation(s)
- Yoojin Lee
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA
| | - Siqi Hu
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA
| | - Young-Ki Park
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA
| | - Ji-Young Lee
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA.,Department of Food and Nutrition, Kyung Hee University, Seoul 02447, Korea
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102
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Najjar SM, Perdomo G. Hepatic Insulin Clearance: Mechanism and Physiology. Physiology (Bethesda) 2019; 34:198-215. [PMID: 30968756 DOI: 10.1152/physiol.00048.2018] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Upon its secretion from pancreatic β-cells, insulin reaches the liver through the portal circulation to exert its action and eventually undergo clearance in the hepatocytes. In addition to insulin secretion, hepatic insulin clearance regulates the homeostatic level of insulin that is required to reach peripheral insulin target tissues to elicit proper insulin action. Receptor-mediated insulin uptake followed by its degradation constitutes the basic mechanism of insulin clearance. Upon its phosphorylation by the insulin receptor tyrosine kinase, carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) takes part in the insulin-insulin receptor complex to increase the rate of its endocytosis and targeting to the degradation pathways. This review summarizes how this process is regulated and how it is associated with insulin-degrading enzyme in the liver. It also discusses the physiological implications of impaired hepatic insulin clearance: Whereas reduced insulin clearance cooperates with increased insulin secretion to compensate for insulin resistance, it can also cause hepatic insulin resistance. Because chronic hyperinsulinemia stimulates hepatic de novo lipogenesis, impaired insulin clearance also causes hepatic steatosis. Thus impaired insulin clearance can underlie the link between hepatic insulin resistance and hepatic steatosis. Delineating these regulatory pathways should lead to building more effective therapeutic strategies against metabolic syndrome.
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Affiliation(s)
- Sonia M Najjar
- Department of Biomedical Sciences, Ohio University , Athens, Ohio.,Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University , Athens, Ohio
| | - Germán Perdomo
- Departamento de Ciencias de la Salud, Universidad de Burgos , Burgos , Spain
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103
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Tanimura Y, Aoi W, Mizushima K, Higashimura Y, Naito Y. Combined treatment of dipeptidyl peptidase-4 inhibitor and exercise training improves lipid profile in KK/Ta mice. Exp Physiol 2019; 104:1051-1060. [PMID: 31020720 DOI: 10.1113/ep087449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/24/2019] [Indexed: 12/18/2022]
Abstract
NEW FINDINGS What is the central question of this study? Exercise for type 2 diabetes patients treated with insulin therapy involves the risk of hypoglycaemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors can be effective in combination with exercise because they reduce the incidence of hypoglycaemia. We evaluated the effect of this combination of treatments on hepatic lipid metabolism in diabetic KK/Ta mice. What is the main finding and its importance? The combination of a DPP-4 inhibitor and exercise, which lowers the risk of hypoglycaemia, is useful for improving insulin resistance by inhibiting excess insulin secretion and decreasing hepatic lipid accumulation, validated by downregulated CD36. ABSTRACT The role of exercise training in prevention of diabetes and/or dyslipidaemia has been firmly established. Dipeptidyl peptidase-4 (DPP-4) inhibitors improve insulin sensitivity and have attracted attention as therapeutics for hepatic lipid accumulation. The effect of a combination of DPP-4 inhibitor and exercise training on the prevention and treatment of hepatic lipid accumulation is unclear. Here, we investigated whether alogliptin, a DPP-4 inhibitor, enhances the preventive effect of exercise-induced hepatic lipid accumulation in diabetic mice. Balb/c and KK/Ta mice were fed a high-fat diet. Mice were divided into the following five groups: B, Balb/c mice; K, KK/Ta mice; K-A, KK/Ta mice with alogliptin (0.01%); K-Ex, KK/Ta mice with exercise training (3 days week-1 , 15-20 m min-1 for 30 min); and K-Ex+A, KK/Ta mice with alogliptin and exercise training (n = 8 or 9 mice per group). After 8 weeks, glucose, insulin and triglyceride concentrations in the blood and triglyceride levels in the liver were significantly lower in the K-Ex+A group than in the K group. The liver expression level of PPAR-γ in the K group was significantly higher than that in the other groups. Additionally, the liver CD36 expression level was significantly lower in the K-Ex+A and B groups than in the K group. Thus, combined therapy of a DPP-4 inhibitor with exercise training was effective against high-fat diet-induced hepatic lipid accumulation in KK/Ta mice. The results of this study provide useful support for the practice of safe exercise therapy even in diabetic patients who require treatment with a DPP-4 inhibitor.
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Affiliation(s)
- Yuko Tanimura
- Faculty of Human Health, Aichi Toho University, Meito-ku, Nagoya, Japan.,Department of Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, Japan
| | - Wataru Aoi
- Division of Applied Life Sciences, Graduate School and Life and Environmental Science, Kyoto Prefectural University, Sakyo-ku, Kyoto, Japan
| | - Katsura Mizushima
- Department of Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, Japan
| | - Yasuki Higashimura
- Department of Bioresources and Environmental Science, Ishikawa Prefectural University, Nonoichi, Japan
| | - Yuji Naito
- Department of Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, Japan
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104
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Guilherme A, Henriques F, Bedard AH, Czech MP. Molecular pathways linking adipose innervation to insulin action in obesity and diabetes mellitus. Nat Rev Endocrinol 2019; 15:207-225. [PMID: 30733616 PMCID: PMC7073451 DOI: 10.1038/s41574-019-0165-y] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Adipose tissue comprises adipocytes and many other cell types that engage in dynamic crosstalk in a highly innervated and vascularized tissue matrix. Although adipose tissue has been studied for decades, it has been appreciated only in the past 5 years that extensive arborization of nerve fibres has a dominant role in regulating the function of adipose tissue. This Review summarizes the latest literature, which suggests that adipocytes signal to local sensory nerve fibres in response to perturbations in lipolysis and lipogenesis. Such adipocyte signalling to the central nervous system causes sympathetic output to distant adipose depots and potentially other metabolic tissues to regulate systemic glucose homeostasis. Paracrine factors identified in the past few years that mediate such adipocyte-neuron crosstalk are also reviewed. Similarly, immune cells and endothelial cells within adipose tissue communicate with local nerve fibres to modulate neurotransmitter tone, blood flow, adipocyte differentiation and energy expenditure, including adipose browning to produce heat. This understudied field of neurometabolism related to adipose tissue biology has great potential to reveal new mechanistic insights and potential therapeutic strategies for obesity and type 2 diabetes mellitus.
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Affiliation(s)
- Adilson Guilherme
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Felipe Henriques
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Alexander H Bedard
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
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105
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Zoeller RA, Geoghegan-Barek K. A cell-based high-throughput screen identifies tyrphostin AG 879 as an inhibitor of animal cell phospholipid and fatty acid biosynthesis. Biochem Biophys Rep 2019; 18:100621. [PMID: 30899803 PMCID: PMC6406593 DOI: 10.1016/j.bbrep.2019.100621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 02/18/2019] [Indexed: 01/02/2023] Open
Abstract
Inhibition of animal cell phospholipid biosynthesis has been proposed for anticancer and antiviral therapies. Using CHO—K1 derived cell lines, we have developed and used a cell-based high-throughput procedure to screen a 1280 compound, small molecule library for inhibitors of phospholipid biosynthesis. We identified tyrphostin AG 879 (AG879), which inhibited phospholipid biosynthesis by 85–90% at a concentration of 10 μM, displaying an IC50 of 1–3 μM. The synthesis of all phospholipid head group classes was heavily affected. Fatty acid biosynthesis was also dramatically inhibited (90%). AG879 inhibited phospholipid biosynthesis in all additional cell lines tested, including MDCK, HUH7, Vero, and HeLa cell lines. In CHO cells, AG879 was cytostatic; cells survived for at least four days during exposure and were able to divide following its removal. AG879 is an inhibitor of receptor tyrosine kinases (RTK) and inhibitors of signaling pathways known to be activated by RTK's also inhibited phospholipid biosynthesis. We speculate that inhibition of RTK by AG879 results in an inhibition of fatty acid biosynthesis with a resulting decrease in phospholipid biosynthesis and that AG879's effect on fatty acid synthesis and/or phospholipid biosynthesis may contribute to its known capacity as an effective antiviral/anticancer agent.
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Key Words
- 32Pi, [32P]orthophosphate
- AFU, Arbitrary fluorescence units
- AG879, Tyrphostin AG 879
- Anticancer
- Antiviral
- CE, Cholesterol ester
- CL, Cardiolipin
- Drug screening
- EGFR, Epidermal growth factor receptor
- Fatty acid biosynthesis
- HER2, Human epidermal growth factor receptor 2
- HTS, High-throughput screen
- P12, 12-(1′-pyrene) dodecanoic acid
- PA, Phosphatidic acid
- PC, Phosphatidylcholine
- PE, Phosphatidylethanolamine
- PI, Phosphatidylinositol
- PL, Phospholipid
- Phospholipid biosynthesis
- RTK, Receptor tyrosine kinase
- TG, Triacylglycerol
- Tyrphostin AG 879
- trkA, Tropomyosin analogue receptor kinase
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Affiliation(s)
- Raphael A Zoeller
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany Street, Room W302, Boston, MA, 02118, USA
| | - Kathleen Geoghegan-Barek
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany Street, Room W302, Boston, MA, 02118, USA
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106
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Clemente-Postigo M, Oliva-Olivera W, Coin-Aragüez L, Ramos-Molina B, Giraldez-Perez RM, Lhamyani S, Alcaide-Torres J, Perez-Martinez P, El Bekay R, Cardona F, Tinahones FJ. Metabolic endotoxemia promotes adipose dysfunction and inflammation in human obesity. Am J Physiol Endocrinol Metab 2019; 316:E319-E332. [PMID: 30422702 DOI: 10.1152/ajpendo.00277.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Impaired adipose tissue (AT) lipid handling and inflammation is associated with obesity-related metabolic diseases. Circulating lipopolysaccharides (LPSs) from gut microbiota (metabolic endotoxemia), proposed as a triggering factor for the low-grade inflammation in obesity, might also be responsible for AT dysfunction. Nevertheless, this hypothesis has not been explored in human obesity. To analyze the relationship between metabolic endotoxemia and AT markers for lipogenesis, lipid handling, and inflammation in human obesity, 33 patients with obesity scheduled for surgery were recruited and classified according to their LPS levels. Visceral and subcutaneous AT gene and protein expression were analyzed and adipocyte and AT in vitro assays performed. Subjects with obesity with a high degree of metabolic endotoxemia had lower expression of key genes for AT function and lipogenesis ( SREBP1, FABP4, FASN, and LEP) but higher expression of inflammatory genes in visceral and subcutaneous AT than subjects with low LPS levels. In vitro experiments corroborated that LPS are responsible for adipocyte and AT inflammation and downregulation of PPARG, SCD, FABP4, and LEP expression and LEP secretion. Thus, metabolic endotoxemia influences AT physiology in human obesity by decreasing the expression of factors involved in AT lipid handling and function as well as by increasing inflammation.
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Affiliation(s)
- Mercedes Clemente-Postigo
- Unidad de Gestión Clínica Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria/Universidad de Málaga. Málaga, Spain
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
| | - Wilfredo Oliva-Olivera
- Unidad de Gestión Clínica Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria/Universidad de Málaga. Málaga, Spain
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
| | - Leticia Coin-Aragüez
- Unidad de Gestión Clínica Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria/Universidad de Málaga. Málaga, Spain
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
| | - Bruno Ramos-Molina
- Unidad de Gestión Clínica Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria/Universidad de Málaga. Málaga, Spain
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
| | - Rosa María Giraldez-Perez
- Departamento Biología Celular, Genética y Fisiología, Facultad de Ciencias. Universidad de Málaga , Spain
| | - Said Lhamyani
- Unidad de Gestión Clínica de Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario/Universidad de Málaga , Málaga , Spain
| | - Juan Alcaide-Torres
- Unidad de Gestión Clínica Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria/Universidad de Málaga. Málaga, Spain
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
| | - Pablo Perez-Martinez
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
- Lipid and Atherosclerosis Research Unit, Reina Sofia University Hospital, University of Cordoba , Cordoba , Spain
| | - Rajaa El Bekay
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
- Unidad de Gestión Clínica de Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario/Universidad de Málaga , Málaga , Spain
| | - Fernando Cardona
- Unidad de Gestión Clínica Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria/Universidad de Málaga. Málaga, Spain
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
| | - Francisco J Tinahones
- Unidad de Gestión Clínica Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria/Universidad de Málaga. Málaga, Spain
- Centro de Investigación Biomédica En Red (CIBER) Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII) , Málaga , Spain
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107
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Pereira VAR, Vedovelli KS, Muller GY, Depieri YF, Avelar DHCG, de Amo AHE, Jimenes DR, Martins JNL, Silvério AC, Gomes CRG, Godoi VAF, Pedrosa MMD. Pros and cons of insulin administration on liver glucose metabolism in strength-trained healthy mice. ACTA ACUST UNITED AC 2019; 52:e7637. [PMID: 30698225 PMCID: PMC6345355 DOI: 10.1590/1414-431x20187637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 11/08/2018] [Indexed: 11/22/2022]
Abstract
Non-diabetic individuals use hormones like insulin to improve muscle strength and performance. However, as insulin also leads the liver and the adipose tissue to an anabolic state, the purpose of this study was to investigate the effects of insulin on liver metabolism in trained non-diabetic Swiss mice. The mice were divided into four groups: sedentary treated with saline (SS) or insulin (SI) and trained treated with saline (TS) or insulin (TI). Training was made in a vertical stair, at 90% of the maximum load, three times per week. Insulin (0.3 U/kg body weight) or saline were given intraperitoneally five times per week. After eight weeks, tissue and blood were collected and in situ liver perfusion with glycerol+lactate or alanine+glutamine (4 mM each) was carried out. The trained animals increased their muscle strength (+100%) and decreased body weight gain (–11%), subcutaneous fat (–42%), mesenteric fat (–45%), and peritoneal adipocyte size (–33%) compared with the sedentary groups. Insulin prevented the adipose effects of training (TI). The gastrocnemius muscle had greater density of muscle fibers (+60%) and less connective tissue in the trained groups. Liver glycogen was increased by insulin (SI +40% and TI +117%), as well as liver basal glucose release (TI +40%). Lactate and pyruvate release were reduced to a half by training. The greater gluconeogenesis from alanine+glutamine induced by training (TS +50%) was reversed by insulin (TI). Insulin administration had no additional effect on muscle strength and reversed some of the lipolytic and gluconeogenic effects of the resistance training. Therefore, insulin administration does not complement training in improving liver glucose metabolism.
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Affiliation(s)
- V A R Pereira
- Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - K S Vedovelli
- Especialização em Fisiologia Humana, Departamento de Ciências Fisiológicas, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - G Y Muller
- Graduação em Educação Física, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - Y F Depieri
- Graduação em Medicina, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - D H C G Avelar
- Graduação em Educação Física, Centro Metropolitano de Maringá, Maringá, PR, Brasil
| | - A H E de Amo
- Graduação em Ciências Biológicas, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - D R Jimenes
- Especialização em Anatomia e Fisiologia, Departamento de Ciências Morfológicas, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - J N L Martins
- Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - A C Silvério
- Graduação em Biotecnologia, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - C R G Gomes
- Departamento de Ciências Morfológicas, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - V A F Godoi
- Departamento de Ciências Fisiológicas, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - M M D Pedrosa
- Departamento de Ciências Fisiológicas, Universidade Estadual de Maringá, Maringá, PR, Brasil
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108
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Almog T, Kandel Kfir M, Levkovich H, Shlomai G, Barshack I, Stienstra R, Lustig Y, Leikin Frenkel A, Harari A, Bujanover Y, Apte R, Shaish A, Harats D, Kamari Y. Interleukin-1α deficiency reduces adiposity, glucose intolerance and hepatic de-novo lipogenesis in diet-induced obese mice. BMJ Open Diabetes Res Care 2019; 7:e000650. [PMID: 31749969 PMCID: PMC6827792 DOI: 10.1136/bmjdrc-2019-000650] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVE While extensive research revealed that interleukin (IL)-1β contributes to insulin resistance (IR) development, the role of IL-1α in obesity and IR was scarcely studied. Using control, whole body IL-1α knockout (KO) or myeloid-cell-specific IL-1α-deficient mice, we tested the hypothesis that IL-1α deficiency would protect against high-fat diet (HFD)-induced obesity and its metabolic consequences. RESEARCH DESIGN AND METHODS To induce obesity and IR, control and IL-1α KO mice were given either chow or HFD for 16 weeks. Glucose tolerance test was performed at 10 and 15 weeks, representing early and progressive stages of glucose intolerance, respectively. Liver and epididymal white adipose tissue (eWAT) samples were analyzed for general morphology and adipocyte size. Plasma levels of adiponectin, insulin, total cholesterol and triglyceride (TG), lipoprotein profile as well as hepatic lipids were analyzed. Expression of lipid and inflammation-related genes in liver and eWAT was analyzed. Primary mouse hepatocytes isolated from control mice were treated either with dimethyl sulfoxide (DMSO) (control) or 20 ng/mL recombinant IL-1α for 24 hours and subjected to gene expression analysis. RESULTS Although total body weight gain was similar, IL-1α KO mice showed reduced adiposity and were completely protected from HFD-induced glucose intolerance. In addition, plasma total cholesterol and TG levels were lower and HFD-induced accumulation of liver TGs was completely inhibited in IL-1α KO compared with control mice. Expression of stearoyl-CoA desaturase1 (SCD1), fatty acid synthase (FASN), elongation of long-chain fatty acids family member 6 (ELOVL6), acetyl-CoA carboxylase (ACC), key enzymes that promote de-novo lipogenesis, was lower in livers of IL-1α KO mice. Treatment with recombinant IL-1α elevated the expression of ELOVL6 and FASN in mouse primary hepatocytes. Finally, mice with myeloid-cell-specific deletion of IL-1α did not show reduced adiposity and improved glucose tolerance. CONCLUSIONS We demonstrate a novel role of IL-1α in promoting adiposity, obesity-induced glucose intolerance and liver TG accumulation and suggest that IL-1α blockade could be used for treatment of obesity and its metabolic consequences.
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Affiliation(s)
- Tal Almog
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Michal Kandel Kfir
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Hana Levkovich
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Gadi Shlomai
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Iris Barshack
- The Pathology Department, Sheba Medical Center, Tel Hashomer, Israel
- Departments of Medicine and Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rinke Stienstra
- Department of Medicine, Radboud University, Nijmegen, The Netherlands
- Department of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Yaniv Lustig
- The Institute of Endocrinology, Sheba Medical Center, Tel Hashomer, Israel
| | - Alicia Leikin Frenkel
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
- Departments of Medicine and Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ayelet Harari
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Yoram Bujanover
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Roni Apte
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Aviv Shaish
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
- Department of life sciences, Achva Academic College, Shikmim, Israel
| | - Dror Harats
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
- Departments of Medicine and Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yehuda Kamari
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
- Departments of Medicine and Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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109
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Li Y, Meng Y, Yu X. The Unique Metabolic Characteristics of Bone Marrow Adipose Tissue. Front Endocrinol (Lausanne) 2019; 10:69. [PMID: 30800100 PMCID: PMC6375842 DOI: 10.3389/fendo.2019.00069] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 01/24/2019] [Indexed: 02/05/2023] Open
Abstract
Bone marrow adipose tissue (MAT) is distinct from white adipose tissue (WAT) or brown adipose tissue (BAT) for its location, feature and function. As a largely ignored adipose depot, it is situated in bone marrow space and resided with bone tissue side-by-side. MAT is considered not only as a regulator of bone metabolism through paracrine, but also as a functionally particular adipose tissue that may contribute to global metabolism. Adipokines, inflammatory factors and other molecules derived from bone marrow adipocytes may exert systematic effects. In this review, we summary the evidence from several aspects including development, distribution, histological features and phenotype to elaborate the basic characteristics of MAT. We discuss the association between bone metabolism and MAT, and highlight our current understanding of this special adipose tissue. We further demonstrate the probable relationship between MAT and energy metabolism, as well as glucose metabolism. On the basis of preliminary results from animal model and clinical studies, we propose that MAT has its unique secretory and metabolic function, although there is no in-depth study at present.
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Affiliation(s)
- Yujue Li
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology and Metabolism and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Yang Meng
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology and Metabolism and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, China
| | - Xijie Yu
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology and Metabolism and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Xijie Yu ;
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Millership SJ, Tunster SJ, Van de Pette M, Choudhury AI, Irvine EE, Christian M, Fisher AG, John RM, Scott J, Withers DJ. Neuronatin deletion causes postnatal growth restriction and adult obesity in 129S2/Sv mice. Mol Metab 2018; 18:97-106. [PMID: 30279096 PMCID: PMC6308027 DOI: 10.1016/j.molmet.2018.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 09/10/2018] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVE Imprinted genes are crucial for the growth and development of fetal and juvenile mammals. Altered imprinted gene dosage causes a variety of human disorders, with growth and development during these crucial early stages strongly linked with future metabolic health in adulthood. Neuronatin (Nnat) is a paternally expressed imprinted gene found in neuroendocrine systems and white adipose tissue and is regulated by the diet and leptin. Neuronatin expression is downregulated in obese children and has been associated with stochastic obesity in C57BL/6 mice. However, our recent studies of Nnat null mice on this genetic background failed to display any body weight or feeding phenotypes but revealed a defect in glucose-stimulated insulin secretion due to the ability of neuronatin to potentiate signal peptidase cleavage of preproinsulin. Nnat deficiency in beta cells therefore caused a lack of appropriate storage and secretion of mature insulin. METHODS To further explore the potential role of Nnat in the regulation of body weight and adiposity, we studied classical imprinting-related phenotypes such as placental, fetal, and postnatal growth trajectory patterns that may impact upon subsequent adult metabolic phenotypes. RESULTS Here we find that, in contrast to the lack of any body weight or feeding phenotypes on the C57BL/6J background, deletion of Nnat in mice on 129S2/Sv background causes a postnatal growth restriction with reduced adipose tissue accumulation, followed by catch up growth after weaning. This was in the absence of any effect on fetal growth or placental development. In adult 129S2/Sv mice, Nnat deletion was associated with hyperphagia, reduced energy expenditure, and partial leptin resistance. Lack of neuronatin also potentiated obesity caused by either aging or high fat diet feeding. CONCLUSIONS The imprinted gene Nnat plays a key role in postnatal growth, adult energy homeostasis, and the pathogenesis of obesity via catch up growth effects, but this role is dependent upon genetic background.
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Affiliation(s)
- Steven J Millership
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Simon J Tunster
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | | | | | - Elaine E Irvine
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Mark Christian
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Amanda G Fisher
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Rosalind M John
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - James Scott
- National Heart and Lung Institute, Department of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
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111
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Bódis K, Roden M. Energy metabolism of white adipose tissue and insulin resistance in humans. Eur J Clin Invest 2018; 48:e13017. [PMID: 30107041 DOI: 10.1111/eci.13017] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/22/2018] [Accepted: 08/12/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Insulin resistance not only occurs in obesity, but also in lipodystrophy. Although adipose tissue mass affects metabolic fluxes and participates in interorgan crosstalk, the role of energy metabolism within white adipose tissue for insulin resistance is less clear. MATERIALS AND METHODS A Medline search identified in vivo studies in humans on energy and lipid metabolism in subcutaneous (SAT) and visceral adipose tissue (VAT). Studies in adipocyte cultures and transgenic animal models were included for the better understanding of the link between abnormal energy metabolism in adipose tissue and insulin resistance. RESULTS The current literature indicates that higher lipolysis and lower lipogenesis in VAT compared to SAT enhance portal delivery of lipid metabolites (glycerol and fatty acids) to the liver. Thus, the lower lipolysis and higher lipogenesis in SAT favour storage of excess lipids and allow for protection of insulin-sensitive tissues from lipotoxic effects. In insulin-resistant humans, enhanced lipolysis and impaired lipogenesis in adipose tissue lead to release of cytokines and lipid metabolites, ultimately promoting insulin resistance. Adipose tissue of insulin-resistant humans also displays lower expression of proteins involved in mitochondrial function. In turn, this leads to lower availability of mitochondria-derived energy sources for lipogenesis in adipose tissue. CONCLUSIONS Abnormal mitochondrial function in human white adipose tissue likely contributes to the secretion of lipid metabolites and lactate, which are linked to insulin resistance in peripheral tissues. However, the relevance of adipose tissue energy metabolism for the regulation of human insulin sensitivity remains to be further elucidated.
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Affiliation(s)
- Kálmán Bódis
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany.,Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Michael Roden
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany.,Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
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112
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Loves S, van Groningen L, Filius M, Mekking M, Brandon T, Tack CJ, Hermus A, de Boer H. High-Dose, Diazoxide-Mediated Insulin Suppression Boosts Weight Loss Induced by Lifestyle Intervention. J Clin Endocrinol Metab 2018; 103:4014-4022. [PMID: 30202851 DOI: 10.1210/jc.2018-01147] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/04/2018] [Indexed: 12/26/2022]
Abstract
CONTEXT Obesity-related hyperinsulinism may impede lifestyle-initiated weight loss. OBJECTIVE Proof-of-concept study to investigate the amplifying effects of diazoxide (DZX)-mediated insulin suppression on lifestyle-induced weight loss in nondiabetic, hyperinsulinemic, obese men. DESIGN Twelve-month study comprising an initial 6-month, double-blind trial, followed by a partially de-blinded 6-month extension in men with obesity with a body mass index of 30 to 37.5 kg/m2 and a fasting serum C-peptide level >1.00 nM. Patients were randomized into three treatment groups: DZX + placebo (DZX + PL), DZX + metformin (DZX + MTF), and double PL (PL + PL). RESULTS At 6 months, DZX treatment was associated with a 6.1-kg PL-subtracted decline in fat mass (FM), and at 12 months, FM had decreased by a total of 15.7 ± 2.5 kg. Twelve months of DZX treatment was also associated with a significant decline in systolic (-6.6%) and diastolic (-8.6%) blood pressure and low-density lipoprotein-cholesterol (-18%) and triglycerides (-43%) and a 39% rise in high-density lipoprotein-cholesterol. These effects were achieved at the cost of a small rise in fasting glucose (95% CI: 0.2 to 1.0 mM) and hemoglobin A1c (95% CI: -0.08% to 0.44%). There were no differences between DZX monotherapy and the combination of DZX + MTF. CONCLUSION High-dose DZX treatment of 1 year resulted in a substantial decrease in FM, blood pressure, and lipid levels at the cost of a small rise in blood glucose levels.
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Affiliation(s)
- Sandra Loves
- Department of Internal Medicine, Rijnstate Hospital, AD Arnhem, Netherlands
| | | | - Margreet Filius
- Department of Clinical Pharmacy, Rijnstate Hospital, AD Arnhem, Netherlands
| | - Marja Mekking
- Department of Clinical Chemistry, Rijnstate Hospital, AD Arnhem, Netherlands
| | - Tom Brandon
- Department of Sports Medicine, Rijnstate Hospital, AD Arnhem, Netherlands
| | - Cees J Tack
- Department of Internal Medicine, Radboud University, Nijmegen Medical Centre, GA Nijmegen, Netherlands
| | - Ad Hermus
- Department of Internal Medicine, Radboud University, Nijmegen Medical Centre, GA Nijmegen, Netherlands
| | - Hans de Boer
- Department of Internal Medicine, Rijnstate Hospital, AD Arnhem, Netherlands
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Abstract
The hypothalamus is the brain region responsible for the maintenance of energetic homeostasis. The regulation of this process arises from the ability of the hypothalamus to orchestrate complex physiological responses such as food intake and energy expenditure, circadian rhythm, stress response, and fertility. Metabolic alterations such as obesity can compromise these hypothalamic regulatory functions. Alterations in circadian rhythm, stress response, and fertility further contribute to aggravate the metabolic dysfunction of obesity and contribute to the development of chronic disorders such as depression and infertility.At cellular level, obesity caused by overnutrition can damage the hypothalamus promoting inflammation and impairing hypothalamic neurogenesis. Furthermore, hypothalamic neurons suffer apoptosis and impairment in synaptic plasticity that can compromise the proper functioning of the hypothalamus. Several factors contribute to these phenomena such as ER stress, oxidative stress, and impairments in autophagy. All these observations occur at the same time and it is still difficult to discern whether inflammatory processes are the main drivers of these cellular dysfunctions or if the hypothalamic hormone resistance (insulin, leptin, and ghrelin) can be pinpointed as the source of several of these events.Understanding the mechanisms that underlie the pathophysiology of obesity in the hypothalamus is crucial for the development of strategies that can prevent or attenuate the deleterious effects of obesity.
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114
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Song Z, Xiaoli AM, Yang F. Regulation and Metabolic Significance of De Novo Lipogenesis in Adipose Tissues. Nutrients 2018; 10:nu10101383. [PMID: 30274245 PMCID: PMC6213738 DOI: 10.3390/nu10101383] [Citation(s) in RCA: 237] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 12/20/2022] Open
Abstract
De novo lipogenesis (DNL) is a complex and highly regulated process in which carbohydrates from circulation are converted into fatty acids that are then used for synthesizing either triglycerides or other lipid molecules. Dysregulation of DNL contributes to human diseases such as obesity, type 2 diabetes, and cardiovascular diseases. Thus, the lipogenic pathway may provide a new therapeutic opportunity for combating various pathological conditions that are associated with dysregulated lipid metabolism. Hepatic DNL has been well documented, but lipogenesis in adipocytes and its contribution to energy homeostasis and insulin sensitivity are less studied. Recent reports have gained significant insights into the signaling pathways that regulate lipogenic transcription factors and the role of DNL in adipose tissues. In this review, we will update the current knowledge of DNL in white and brown adipose tissues with the focus on transcriptional, post-translational, and central regulation of DNL. We will also summarize the recent findings of adipocyte DNL as a source of some signaling molecules that critically regulate energy metabolism.
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Affiliation(s)
- Ziyi Song
- Departments of Medicine and Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Alus M Xiaoli
- Departments of Medicine and Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Fajun Yang
- Departments of Medicine and Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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115
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Dziubak A, Wójcicka G, Wojtak A, Bełtowski J. Metabolic Effects of Metformin in the Failing Heart. Int J Mol Sci 2018; 19:ijms19102869. [PMID: 30248910 PMCID: PMC6213955 DOI: 10.3390/ijms19102869] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/11/2018] [Accepted: 09/17/2018] [Indexed: 01/03/2023] Open
Abstract
Accumulating evidence shows that metformin is an insulin-sensitizing antidiabetic drug widely used in the treatment of type 2 diabetes mellitus (T2DM), which can exert favorable effects on cardiovascular risk and may be safely used in patients with heart failure (HF), and even able to reduce the incidence of HF and to reduce HF mortality. In failing hearts, metformin improves myocardial energy metabolic status through the activation of AMP (adenosine monophosphate)-activated protein kinase (AMPK) and the regulation of lipid and glucose metabolism. By increasing nitric oxide (NO) bioavailability, limiting interstitial fibrosis, reducing the deposition of advanced glycation end-products (AGEs), and inhibiting myocardial cell apoptosis metformin reduces cardiac remodeling and hypertrophy, and thereby preserves left ventricular systolic and diastolic functions. While a lot of preclinical and clinical studies showed the cardiovascular safety of metformin therapy in diabetic patients and HF, to confirm observed benefits, the specific large-scale trials configured for HF development in diabetic patients as a primary endpoints are necessary.
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Affiliation(s)
- Aleksandra Dziubak
- Department of Pathophysiology, Medical University of Lublin, ul. Jaczewskiego 8b, 20-090 Lublin, Poland.
| | - Grażyna Wójcicka
- Department of Pathophysiology, Medical University of Lublin, ul. Jaczewskiego 8b, 20-090 Lublin, Poland.
| | - Andrzej Wojtak
- Department of Vascular Surgery, Medical University of Lubin, 20-090 Lublin, Poland.
| | - Jerzy Bełtowski
- Department of Pathophysiology, Medical University of Lublin, ul. Jaczewskiego 8b, 20-090 Lublin, Poland.
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116
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Ormazabal V, Nair S, Elfeky O, Aguayo C, Salomon C, Zuñiga FA. Association between insulin resistance and the development of cardiovascular disease. Cardiovasc Diabetol 2018; 17:122. [PMID: 30170598 PMCID: PMC6119242 DOI: 10.1186/s12933-018-0762-4] [Citation(s) in RCA: 987] [Impact Index Per Article: 164.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/20/2018] [Indexed: 12/14/2022] Open
Abstract
For many years, cardiovascular disease (CVD) has been the leading cause of death around the world. Often associated with CVD are comorbidities such as obesity, abnormal lipid profiles and insulin resistance. Insulin is a key hormone that functions as a regulator of cellular metabolism in many tissues in the human body. Insulin resistance is defined as a decrease in tissue response to insulin stimulation thus insulin resistance is characterized by defects in uptake and oxidation of glucose, a decrease in glycogen synthesis, and, to a lesser extent, the ability to suppress lipid oxidation. Literature widely suggests that free fatty acids are the predominant substrate used in the adult myocardium for ATP production, however, the cardiac metabolic network is highly flexible and can use other substrates, such as glucose, lactate or amino acids. During insulin resistance, several metabolic alterations induce the development of cardiovascular disease. For instance, insulin resistance can induce an imbalance in glucose metabolism that generates chronic hyperglycemia, which in turn triggers oxidative stress and causes an inflammatory response that leads to cell damage. Insulin resistance can also alter systemic lipid metabolism which then leads to the development of dyslipidemia and the well-known lipid triad: (1) high levels of plasma triglycerides, (2) low levels of high-density lipoprotein, and (3) the appearance of small dense low-density lipoproteins. This triad, along with endothelial dysfunction, which can also be induced by aberrant insulin signaling, contribute to atherosclerotic plaque formation. Regarding the systemic consequences associated with insulin resistance and the metabolic cardiac alterations, it can be concluded that insulin resistance in the myocardium generates damage by at least three different mechanisms: (1) signal transduction alteration, (2) impaired regulation of substrate metabolism, and (3) altered delivery of substrates to the myocardium. The aim of this review is to discuss the mechanisms associated with insulin resistance and the development of CVD. New therapies focused on decreasing insulin resistance may contribute to a decrease in both CVD and atherosclerotic plaque generation.
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Affiliation(s)
- Valeska Ormazabal
- Faculty of Biological Sciences, Pharmacology Department, University of Concepcion, Concepción, Chile
| | - Soumyalekshmi Nair
- Exosome Biology Laboratory, Centre for Clinical Diagnostics, UQ Centre for Clinical Research, Royal Brisbane and Women's Hospital, Faculty of Medicine + Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Omar Elfeky
- Exosome Biology Laboratory, Centre for Clinical Diagnostics, UQ Centre for Clinical Research, Royal Brisbane and Women's Hospital, Faculty of Medicine + Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Claudio Aguayo
- Faculty of Pharmacy, Department of Clinical Biochemistry and Immunology, University of Concepcion, Concepción, Chile
| | - Carlos Salomon
- Exosome Biology Laboratory, Centre for Clinical Diagnostics, UQ Centre for Clinical Research, Royal Brisbane and Women's Hospital, Faculty of Medicine + Biomedical Sciences, The University of Queensland, Brisbane, Australia. .,Faculty of Pharmacy, Department of Clinical Biochemistry and Immunology, University of Concepcion, Concepción, Chile. .,Department of Obstetrics and Gynecology, Ochsner Baptist Hospital, New Orleans, Louisiana, USA.
| | - Felipe A Zuñiga
- Faculty of Pharmacy, Department of Clinical Biochemistry and Immunology, University of Concepcion, Concepción, Chile
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Mendez-Sanchez N, Cruz-Ramon VC, Ramirez-Perez OL, Hwang JP, Barranco-Fragoso B, Cordova-Gallardo J. New Aspects of Lipotoxicity in Nonalcoholic Steatohepatitis. Int J Mol Sci 2018; 19:E2034. [PMID: 30011790 PMCID: PMC6073816 DOI: 10.3390/ijms19072034] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 02/08/2023] Open
Abstract
NASH is becoming increasingly common worldwide because of the growing global prevalence of obesity and consequently NAFLD. Unfortunately, the mechanism of progression of NAFLD to NASH and then cirrhosis is not completely understood. Several factors, including insulin resistance, inflammation, oxidative stress, lipotoxicity, and bile acid (BA) toxicity, have been reported to be associated with NASH progression. The release of fatty acids from dysfunctional and insulin-resistant adipocytes results in lipotoxicity, which is caused by the ectopic accumulation of triglyceride-derived toxic metabolites and the subsequent activation of inflammatory pathways, cellular dysfunction, and lipoapoptosis. Adipose tissue (AT), especially visceral AT, comprises multiple cell populations that produce adipokines and insulin-like growth factor, plus macrophages and other immune cells that stimulate the development of lipotoxic liver disease. These biomolecules have been recently linked with many digestive diseases and gastrointestinal malignancies such as hepatocellular carcinoma. This made us question what role lipotoxicity has in the natural history of liver fibrosis. Therefore, this review focuses on the close relationship between AT and NASH. A good comprehension of the pathways that are related to dysregulated AT, metabolic dysfunction, and hepatic lipotoxicity will result in the development of prevention strategies and promising therapeutics for patients with NASH.
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Affiliation(s)
| | | | | | - Jessica P Hwang
- Department of General Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| | - Beatriz Barranco-Fragoso
- Department of Gastroenterology, National Medical Center "20 Noviembre", 03229 Mexico City, Mexico.
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Loves S, van Groningen L, Filius M, Mekking M, Brandon T, Tack CJ, Hermus A, de Boer H. Effects of Diazoxide-Mediated Insulin Suppression on Glucose and Lipid Metabolism in Nondiabetic Obese Men. J Clin Endocrinol Metab 2018; 103:2346-2353. [PMID: 29618011 DOI: 10.1210/jc.2018-00161] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/26/2018] [Indexed: 02/13/2023]
Abstract
CONTEXT It has been suggested that stimulation of lipolysis by diazoxide (DZX)-mediated insulin suppression may be useful in treating obesity. However, the optimal dose to promote lipolysis without causing hyperglycemia is unknown. OBJECTIVE To assess the effects of DZX in nondiabetic obese men on lipid and glucose metabolism. DESIGN Double-blind, placebo (PL)-controlled, 6-month trial in men with a body mass index of 30 to 37.5 kg/m2 treated with a combination of caloric restriction, a standardized exercise program, and DZX or PL dose escalation. RESULTS The mean maximal tolerated dose of DZX was 422 ± 44 mg/d (range, 200 to 700 mg/d). Dose-limiting events were edema (n = 11), hyperglycemia (n = 6), and nausea (n = 2). After dose reduction to a level free of clinical side effects, DZX treatment was associated with a markedly greater decrease in fasting insulin levels than PL (-72.3 ± 3.5% vs -23.0 ± 12.6%; P < 0.001) and a significant improvement of blood pressure and plasma lipid levels. The decline in insulin levels occurred at the cost of a small increase in plasma glucose (0.6 ± 0.2 mmol/L vs -0.1 ± 0.1 mmol/L; P = 0.04) and hemoglobin A1C (0.2 ± 0.1% vs 0.0 ± 0.1%; P = 0.17). CONCLUSION In nondiabetic obese men, insulin levels can be reduced up to 70% without major metabolic side effects. The marked intersubject variation in maximal tolerated dose indicates that DZX dose titration needs to be individualized.
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Affiliation(s)
- Sandra Loves
- Department of Internal Medicine, Rijnstate Hospital, Arnhem, The Netherlands
| | | | - Margreet Filius
- Department of Clinical Pharmacy, Rijnstate Hospital, Arnhem, The Netherlands
| | - Marja Mekking
- Department of Clinical Chemistry, Rijnstate Hospital, Arnhem, The Netherlands
| | - Tom Brandon
- Department of Sports Medicine, Rijnstate Hospital, Arnhem, The Netherlands
| | - Cees J Tack
- Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Ad Hermus
- Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Hans de Boer
- Department of Internal Medicine, Rijnstate Hospital, Arnhem, The Netherlands
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119
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Tencerova M, Figeac F, Ditzel N, Taipaleenmäki H, Nielsen TK, Kassem M. High-Fat Diet-Induced Obesity Promotes Expansion of Bone Marrow Adipose Tissue and Impairs Skeletal Stem Cell Functions in Mice. J Bone Miner Res 2018; 33:1154-1165. [PMID: 29444341 DOI: 10.1002/jbmr.3408] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/08/2018] [Accepted: 02/09/2018] [Indexed: 12/11/2022]
Abstract
Obesity represents a risk factor for development of insulin resistance and type 2 diabetes. In addition, it has been associated with increased adipocyte formation in the bone marrow (BM) along with increased risk for bone fragility fractures. However, little is known on the cellular mechanisms that link obesity, BM adiposity, and bone fragility. Thus, in an obesity intervention study in C57BL/6J mice fed with a high-fat diet (HFD) for 12 weeks, we investigated the molecular and cellular phenotype of bone marrow adipose tissue (BMAT), BM progenitor cells, and BM microenvironment in comparison to peripheral adipose tissue (AT). HFD decreased trabecular bone mass by 29%, cortical thickness by 5%, and increased BM adiposity by 184%. In contrast to peripheral AT, BMAT did not exhibit pro-inflammatory phenotype. BM progenitor cells isolated from HFD mice exhibited decreased mRNA levels of inflammatory genes (Tnfα, IL1β, Lcn2) and did not manifest an insulin resistant phenotype evidenced by normal levels of pAKT after insulin stimulation as well as normal levels of insulin signaling genes. In addition, BM progenitor cells manifested enhanced adipocyte differentiation in HFD condition. Thus, our data demonstrate that BMAT expansion in response to HFD exerts a deleterious effect on the skeleton. Continuous recruitment of progenitor cells to adipogenesis leads to progenitor cell exhaustion, decreased recruitment to osteoblastic cells, and decreased bone formation. In addition, the absence of insulin resistance and inflammation in the BM suggest that BMAT buffers extra energy in the form of triglycerides and thus plays a role in whole-body energy homeostasis. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Michaela Tencerova
- Department of Molecular Endocrinology, KMEB, University of Southern Denmark and Odense University Hospital, Odense C, Denmark.,Danish Diabetes Academy, Odense C, Denmark
| | - Florence Figeac
- Department of Molecular Endocrinology, KMEB, University of Southern Denmark and Odense University Hospital, Odense C, Denmark
| | - Nicholas Ditzel
- Department of Molecular Endocrinology, KMEB, University of Southern Denmark and Odense University Hospital, Odense C, Denmark
| | - Hanna Taipaleenmäki
- Molecular Skeletal Biology Laboratory, Department of Trauma, Hand, and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tina Kamilla Nielsen
- Department of Molecular Endocrinology, KMEB, University of Southern Denmark and Odense University Hospital, Odense C, Denmark
| | - Moustapha Kassem
- Department of Molecular Endocrinology, KMEB, University of Southern Denmark and Odense University Hospital, Odense C, Denmark.,Department of Cellular and Molecular Medicine, Danish Stem Cell Center (DanStem), University of Copenhagen, Copenhagen, Denmark.,Stem Cell Unit, Department of Anatomy, Faculty of Medicine, King Saud University, Kingdom of Saudi Arabia
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120
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Page MM, Johnson JD. Mild Suppression of Hyperinsulinemia to Treat Obesity and Insulin Resistance. Trends Endocrinol Metab 2018; 29:389-399. [PMID: 29665988 DOI: 10.1016/j.tem.2018.03.018] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/23/2018] [Accepted: 03/27/2018] [Indexed: 12/14/2022]
Abstract
Insulin plays roles in lipid uptake, lipolysis, and lipogenesis, in addition to controlling blood glucose levels. Excessive circulating insulin is associated with adipose tissue expansion and obesity, yet a causal role for hyperinsulinemia in the development of mammalian obesity has proven controversial, with many researchers suggesting it as a consequence of insulin resistance. Recently, evidence that specifically reducing hyperinsulinemia can prevent and reverse obesity in animal models has been presented. Our experiments, and others in this field, question the current dogma that hyperinsulinemia is a response to obesity and/or insulin resistance. In this review, we discuss preclinical evidence in the context of the broader literature and speculate on the possibility of clinical translation of alternative approaches for treating obesity.
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Affiliation(s)
- Melissa M Page
- Life Sciences Institute Diabetes Research Group and the Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada; Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - James D Johnson
- Life Sciences Institute Diabetes Research Group and the Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada. https://twitter.com/JimJohnsonSci
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Abstract
It has been known for a long time that thyroid hormones have prominent effects on hepatic fatty acid and cholesterol synthesis and metabolism. Indeed, hypothyroidism has been associated with increased serum levels of triglycerides and cholesterol as well as non-alcoholic fatty liver disease (NAFLD). Advances in areas such as cell imaging, autophagy and metabolomics have generated a more detailed and comprehensive picture of thyroid-hormone-mediated regulation of hepatic lipid metabolism at the molecular level. In this Review, we describe and summarize the key features of direct thyroid hormone regulation of lipogenesis, fatty acid β-oxidation, cholesterol synthesis and the reverse cholesterol transport pathway in normal and altered thyroid hormone states. Thyroid hormone mediates these effects at the transcriptional and post-translational levels and via autophagy. Given these potentially beneficial effects on lipid metabolism, it is possible that thyroid hormone analogues and/or mimetics might be useful for the treatment of metabolic diseases involving the liver, such as hypercholesterolaemia and NAFLD.
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Affiliation(s)
- Rohit A. Sinha
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
- ;
| | - Brijesh K. Singh
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Paul M. Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
- ;
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Rossmeisl M, Pavlisova J, Janovska P, Kuda O, Bardova K, Hansikova J, Svobodova M, Oseeva M, Veleba J, Kopecky J, Zacek P, Fiserova E, Pelikanova T, Kopecky J. Differential modulation of white adipose tissue endocannabinoid levels by n-3 fatty acids in obese mice and type 2 diabetic patients. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:712-725. [PMID: 29626526 DOI: 10.1016/j.bbalip.2018.03.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 02/16/2018] [Accepted: 03/28/2018] [Indexed: 12/27/2022]
Abstract
n-3 polyunsaturated fatty acids (n-3 PUFA) might regulate metabolism by lowering endocannabinoid levels. We examined time-dependent changes in adipose tissue levels of endocannabinoids as well as in parameters of glucose homeostasis induced by n-3 PUFA in dietary-obese mice, and compared these results with the effect of n-3 PUFA intervention in type 2 diabetic (T2DM) subjects. Male C57BL/6J mice were fed for 8, 16 or 24 weeks a high-fat diet alone (cHF) or supplemented with n-3 PUFA (cHF + F). Overweight/obese, T2DM patients on metformin therapy were given for 24 weeks corn oil (Placebo; 5 g/day) or n-3 PUFA concentrate as above (Omega-3; 5 g/day). Endocannabinoids were measured by liquid chromatography-tandem mass-spectrometry. Compared to cHF-fed controls, the cHF + F mice consistently reduced 2-arachidonoylglycerol (up to ~2-fold at week 24) and anandamide (~2-fold) in adipose tissue, while the levels of endocannabinoid-related anti-inflammatory molecules N-eicosapentaenoyl ethanolamine (EPEA) and N-docosahexaenoyl ethanolamine (DHEA) increased more than ~10-fold and ~8-fold, respectively. At week 24, the cHF + F mice improved glucose tolerance and fasting blood glucose, the latter being positively correlated with adipose 2-arachidonoylglycerol levels only in obese cHF-fed controls, like fasting insulin and HOMA-IR. In the patients, n-3 PUFA failed to reduce 2-arachidonoylglycerol and anandamide levels in adipose tissue and serum, but they increased both adipose tissue and serum levels of EPEA and DHEA. In conclusion, the inability of n-3 PUFA to reduce adipose tissue and serum levels of classical endocannabinoids might contribute to a lack of beneficial effects of these lipids on glucose homeostasis in T2DM patients.
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Affiliation(s)
- Martin Rossmeisl
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
| | - Jana Pavlisova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Petra Janovska
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ondrej Kuda
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Kristina Bardova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jana Hansikova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Michaela Svobodova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Marina Oseeva
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jiri Veleba
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Jan Kopecky
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Petr Zacek
- Proteomics Core Facility, Faculty of Science, Charles University, Division BIOCEV, Vestec, Czech Republic
| | - Eva Fiserova
- Department of Mathematical Analysis and Applications of Mathematics, Faculty of Science, Palacky University, Olomouc, Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Terezie Pelikanova
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Jan Kopecky
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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Pedersen C, Porsgaard T, Thomsen M, Rosenkilde MM, Roed NK. Sustained effect of glucagon on body weight and blood glucose: Assessed by continuous glucose monitoring in diabetic rats. PLoS One 2018; 13:e0194468. [PMID: 29558502 PMCID: PMC5860770 DOI: 10.1371/journal.pone.0194468] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/02/2018] [Indexed: 11/18/2022] Open
Abstract
Insulin is a vital part of diabetes treatment, whereas glucagon is primarily used to treat insulin-induced hypoglycemia. However, glucagon is suggested to have a central role in the regulation of body weight, which would be beneficial for diabetic patients. Since the glucagon effect on blood glucose is known to be transient, it is relevant to investigate the pharmacodynamics of glucagon after repeated dosing. In the present study, we used telemetry to continuously measure blood glucose in streptozotocin induced diabetic Sprague-Dawley rats. This allowed for a more detailed analysis of glucose regulation compared to intermittent blood sampling. In particular, we evaluated the blood glucose-lowering effect of different insulin doses alone, and in combination with a long acting glucagon analog (LAG). We showed how the effect of the LAG accumulated and persisted over time. Furthermore, we found that addition of the LAG decreased body weight without affecting food intake. In a subsequent study, we focused on the glucagon effect on body weight and food intake during equal glycemic control. In order to obtain comparable maximum blood glucose lowering effect to insulin alone, the insulin dose had to be increased four times in combination with 1 nmol/kg of the LAG. In this set-up the LAG prevented further increase in body weight despite the four times higher insulin-dose. However, the body composition was changed. The insulin group increased both lean and fat mass, whereas the group receiving four times insulin in combination with the LAG only significantly increased the fat mass. No differences were observed in food intake, suggesting a direct effect on energy expenditure by glucagon. Surprisingly, we observed decreased levels of FGF21 in plasma compared to insulin treatment alone. With the combination of insulin and the LAG the blood glucose-lowering effect of insulin was prolonged, which could potentially be beneficial in diabetes treatment.
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Affiliation(s)
- Christina Pedersen
- Department of GLP-1 & T2D Biology, Novo Nordisk A/S, Maaloev, Denmark
- Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Trine Porsgaard
- Department of Insulin Pharmacology, Novo Nordisk A/S, Maaloev, Denmark
| | - Maria Thomsen
- Department of Modelling, Novo Nordisk A/S, Maaloev, Denmark
| | - Mette Marie Rosenkilde
- Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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Plaza A, Merino B, Cano V, Domínguez G, Pérez-Castells J, Fernández-Alfonso MS, Sengenès C, Chowen JA, Ruiz-Gayo M. Cholecystokinin is involved in triglyceride fatty acid uptake by rat adipose tissue. J Endocrinol 2018; 236:137-150. [PMID: 29339381 DOI: 10.1530/joe-17-0580] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 01/16/2018] [Indexed: 11/08/2022]
Abstract
The incorporation of plasma triglyceride (TG) fatty acids to white adipose tissue (WAT) depends on lipoprotein lipase (LPL), which is regulated by angiopoietin-like protein-4 (ANGPTL-4), an unfolding molecular chaperone that converts active LPL dimers into inactive monomers. The production of ANGPTL-4 is promoted by fasting and repressed by feeding. We hypothesized that the postprandial hormone cholecystokinin (CCK) facilitates the storage of dietary TG fatty acids in WAT by regulating the activity of the LPL/ANGPTL-4 axis and that it does so by acting directly on CCK receptors in adipocytes. We report that administration of CCK-8 (a bioactive fragment of CCK) to rats: (i) reduces plasma ANGTPL-4 levels; (ii) represses Angptl-4 expression in WAT and (iii) simultaneously enhances LPL activity in this tissue without inducing Lpl expression. In vivo CCK-8 effects are specifically antagonized by the CCK-2 receptor (CCK-2R) antagonist, L-365,260. Moreover, CCK-8 downregulates Angptl-4 expression in wild-type pre-adipocytes, an effect that is not observed in engineered pre-adipocytes lacking CCK-2R. These effects have functional consequences as CCK-8 was found to promote the uptake of dietary fatty acids by WAT, as demonstrated by means of proton nuclear magnetic resonance (1H-NMR). The efficacy of acute CCK-8 administration was not reduced after chronic CCK-8 treatment. Moreover, the effects of CCK-8 on WAT were not associated to the increase of circulating insulin. Our results show that cholecystokinin promotes lipid storage in WAT by acting on adipocyte CCK-2R, suggesting a pivotal role for CCK in TG homeostasis.
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Affiliation(s)
- Adrián Plaza
- Departamento de Ciencias Farmacéuticas y de la SaludFacultad de Farmacia, Universidad San Pablo-CEU, Madrid, Spain
| | - Beatriz Merino
- Departamento de Ciencias Farmacéuticas y de la SaludFacultad de Farmacia, Universidad San Pablo-CEU, Madrid, Spain
| | - Victoria Cano
- Departamento de Ciencias Farmacéuticas y de la SaludFacultad de Farmacia, Universidad San Pablo-CEU, Madrid, Spain
| | - Gema Domínguez
- Departamento de Química y BioquímicaFacultad de Farmacia, Universidad San Pablo-CEU, Madrid, Spain
| | - Javier Pérez-Castells
- Departamento de Química y BioquímicaFacultad de Farmacia, Universidad San Pablo-CEU, Madrid, Spain
| | | | - Coralie Sengenès
- STROMALabUniversité de Toulouse, CNRS ERL5311, EFS, INP-ENVT, Inserm U1031, UPS, Toulouse, France
| | - Julie A Chowen
- Departamento de EndocrinologíaHospital Infantil Universitario Niño Jesús, Instituto de Investigación Sanitaria Princesa, CIBEROBN Instituto Carlos III, Madrid, Spain
| | - Mariano Ruiz-Gayo
- Departamento de Ciencias Farmacéuticas y de la SaludFacultad de Farmacia, Universidad San Pablo-CEU, Madrid, Spain
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Misawa N, Hosoya T, Yoshida S, Sugimoto O, Yamada-Kato T, Kumazawa S. 5-Hydroxyferulic acid methyl ester isolated from wasabi leaves inhibits 3T3-L1 adipocyte differentiation. Phytother Res 2018; 32:1304-1310. [DOI: 10.1002/ptr.6060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/27/2017] [Accepted: 01/23/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Naoki Misawa
- Department of Food and Nutritional Sciences; University of Shizuoka; 52-1 Yada, Suruga-ku Shizuoka 422-8526 Japan
| | - Takahiro Hosoya
- Department of Food and Nutritional Sciences; University of Shizuoka; 52-1 Yada, Suruga-ku Shizuoka 422-8526 Japan
| | - Shuhei Yoshida
- Department of Food and Nutritional Sciences; University of Shizuoka; 52-1 Yada, Suruga-ku Shizuoka 422-8526 Japan
| | - Osamu Sugimoto
- Department of Food and Nutritional Sciences; University of Shizuoka; 52-1 Yada, Suruga-ku Shizuoka 422-8526 Japan
| | - Tomoe Yamada-Kato
- Research and Development Division; Kinjirushi Co. Ltd.; 2-61 Yahata-hontori, Nakagawa-ku Nagoya 454-8526 Japan
| | - Shigenori Kumazawa
- Department of Food and Nutritional Sciences; University of Shizuoka; 52-1 Yada, Suruga-ku Shizuoka 422-8526 Japan
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126
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Kuda O, Rossmeisl M, Kopecky J. Omega-3 fatty acids and adipose tissue biology. Mol Aspects Med 2018; 64:147-160. [PMID: 29329795 DOI: 10.1016/j.mam.2018.01.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/05/2018] [Accepted: 01/08/2018] [Indexed: 12/16/2022]
Abstract
This review provides evidence for the importance of white and brown adipose tissue (i.e. WAT and BAT) function for the maintenance of healthy metabolic phenotype and its preservation in response to omega-3 polyunsaturated fatty acids (omega-3 PUFA), namely in the context of diseased states linked to aberrant accumulation of body fat, systemic low-grade inflammation, dyslipidemia and insulin resistance. More specifically, the review deals with (i) the concept of immunometabolism, i.e. how adipose-resident immune cells and adipocytes affect each other and define the immune-metabolic interface; and (ii) the characteristic features of "healthy adipocytes" in WAT, which are relatively small fat cells endowed with a high capacity for mitochondrial oxidative phosphorylation, triacylglycerol/fatty acid (TAG/FA) cycling and de novo lipogenesis (DNL). The intrinsic metabolic features of WAT and their flexible regulations, reflecting the presence of "healthy adipocytes", provide beneficial local and systemic effects, including (i) protection against in situ endoplasmic reticulum stress and related inflammatory response during activation of adipocyte lipolysis; (ii) prevention of ectopic fat accumulation and dyslipidemia caused by increased hepatic VLDL synthesis, as well as prevention of lipotoxic damage of insulin signaling in extra-adipose tissues; and also (iii) increased synthesis of anti-inflammatory and insulin-sensitizing lipid mediators with pro-resolving properties, including the branched fatty acid esters of hydroxy fatty acids (FAHFAs), also depending on the activity of DNL in WAT. The "healthy adipocytes" phenotype can be induced in WAT of obese mice in response to various stimuli including dietary omega-3 PUFA, especially when combined with moderate calorie restriction, and possibly also with other life style (e.g. physical activity) or pharmacological (e.g. thiazolidinediones) interventions. While omega-3 PUFA could exert beneficial systemic effects by improving immunometabolism of WAT without a concomitant induction of BAT, it is currently not clear whether the metabolic effects of the combined intervention using omega-3 PUFA and calorie restriction or thiazolidinediones depend also on the activation of BAT function and/or the induction of brite/beige adipocytes in WAT. It remains to be established why omega-3 PUFA intervention in type 2 diabetic subjects does not improve insulin sensitivity and glucose homeostasis despite inducing various anti-inflammatory mediators in WAT, including the recently discovered docosahexaenoyl esters of hydroxy linoleic acid, the lipokines from the FAHFA family, as well as several endocannabinoid-related anti-inflammatory lipids. To answer the question whether and to which extent omega-3 PUFA supplementation could promote the formation of "healthy adipocytes" in WAT of human subjects, namely in the obese insulin-resistant patients, represents a challenging task that is of great importance for the treatment of some serious non-communicable diseases.
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Affiliation(s)
- Ondrej Kuda
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska, 1083 Prague 4, Czech Republic
| | - Martin Rossmeisl
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska, 1083 Prague 4, Czech Republic
| | - Jan Kopecky
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska, 1083 Prague 4, Czech Republic.
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127
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Page MM, Skovsø S, Cen H, Chiu AP, Dionne DA, Hutchinson DF, Lim GE, Szabat M, Flibotte S, Sinha S, Nislow C, Rodrigues B, Johnson JD. Reducing insulin via conditional partial gene ablation in adults reverses diet-induced weight gain. FASEB J 2018; 32:1196-1206. [PMID: 29122848 PMCID: PMC5892722 DOI: 10.1096/fj.201700518r] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Excess circulating insulin is associated with obesity in humans and in animal models. However, the physiologic causality of hyperinsulinemia in adult obesity has rightfully been questioned because of the absence of clear evidence that weight loss can be induced by acutely reversing diet-induced hyperinsulinemia. Herein, we describe the consequences of inducible, partial insulin gene deletion in a mouse model in which animals have already been made obese by consuming a high-fat diet. A modest reduction in insulin production/secretion was sufficient to cause significant weight loss within 5 wk, with a specific effect on visceral adipose tissue. This result was associated with a reduction in the protein abundance of the lipodystrophy gene polymerase I and transcript release factor ( Ptrf; Cavin) in gonadal adipose tissue. RNAseq analysis showed that reduced insulin and weight loss also associated with a signature of reduced innate immunity. This study demonstrates that changes in circulating insulin that are too fine to adversely affect glucose homeostasis nonetheless exert control over adiposity.-Page, M. M., Skovsø, S., Cen, H., Chiu, A. P., Dionne, D. A., Hutchinson, D. F., Lim, G. E., Szabat, M., Flibotte, S., Sinha, S., Nislow, C., Rodrigues, B., Johnson, J. D. Reducing insulin via conditional partial gene ablation in adults reverses diet-induced weight gain.
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Affiliation(s)
- Melissa M Page
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Søs Skovsø
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Haoning Cen
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amy P Chiu
- Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Derek A Dionne
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Daria F Hutchinson
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gareth E Lim
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marta Szabat
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephane Flibotte
- Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sunita Sinha
- Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Corey Nislow
- Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian Rodrigues
- Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
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128
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Selected Phyto and Marine Bioactive Compounds: Alternatives for the Treatment of Type 2 Diabetes. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2018. [DOI: 10.1016/b978-0-444-64068-0.00004-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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129
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Li X, Sun K. Regulation of Lipolysis in Adipose Tissue and Clinical Significance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1090:199-210. [PMID: 30390292 DOI: 10.1007/978-981-13-1286-1_11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Lipolysis is a critical process to hydrolyze triglyceride in adipose tissue, thereby breaking down the stored lipid and maintaining energy homeostasis. Recent studies have made significant progress in understanding the steps of lipolysis. This chapter discusses the major pathways that regulate lipolysis in adipose tissue. Specifically we focus on the mechanisms by which the activities of critical lipolytic enzymes are regulated. We further discuss how the lipolysis is regulated by other factors, including insulin and neurotransmitters, in particular catecholamines and the role of sympathetic nervous system in the whole process. Finally we provide clinical perspectives about the novel therapeutic strategies to target or promote adipose tissue lipolysis for treatment/prevention of obesity and type 2 diabetes.
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Affiliation(s)
- Xin Li
- Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Kai Sun
- Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA.
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130
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Kumari M, Heeren J, Scheja L. Regulation of immunometabolism in adipose tissue. Semin Immunopathol 2017; 40:189-202. [DOI: 10.1007/s00281-017-0668-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 11/22/2017] [Indexed: 12/14/2022]
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131
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Massafra V, van Mil SWC. Farnesoid X receptor: A "homeostat" for hepatic nutrient metabolism. Biochim Biophys Acta Mol Basis Dis 2017; 1864:45-59. [PMID: 28986309 DOI: 10.1016/j.bbadis.2017.10.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/27/2017] [Accepted: 10/02/2017] [Indexed: 02/06/2023]
Abstract
The Farnesoid X receptor (FXR) is a nuclear receptor activated by bile acids (BAs). BAs are amphipathic molecules that serve as fat solubilizers in the intestine under postprandial conditions. In the post-absorptive state, BAs bind FXR in the hepatocytes, which in turn provides feedback signals on BA synthesis and transport and regulates lipid, glucose and amino acid metabolism. Therefore, FXR acts as a homeostat of all three classes of nutrients, fats, sugars and proteins. Here we re-analyze the function of FXR in the perspective of nutritional metabolism, and discuss the role of FXR in liver energy homeostasis in postprandial, post-absorptive and fasting/starvation states. FXR, by regulating nutritional metabolism, represses autophagy in conditions of nutrient abundance, and controls the metabolic needs of proliferative cells. In addition, FXR regulates inflammation via direct effects and via its impact on nutrient metabolism. These functions indicate that FXR is an attractive therapeutic target for liver diseases.
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Affiliation(s)
- Vittoria Massafra
- Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands
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132
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Kandror K. Mammalian target of rapamycin complex 1 and FoxO1 in the transcriptional control of lipolysis and de novo lipogenesis. Curr Opin Endocrinol Diabetes Obes 2017; 24:326-331. [PMID: 28841634 PMCID: PMC11210950 DOI: 10.1097/med.0000000000000352] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
PURPOSE OF REVIEW Postprandial suppression of lipolysis in adipose tissue and stimulation of de novo lipogenesis (DNL) in the liver by insulin are essential for the metabolic homeostasis in the mammalian organism. The mechanism of coregulation of lipolysis and DNL is not clear. RECENT FINDINGS Insulin controls both lipolysis and DNL at the level of transcription via the same mammalian target of rapamycin complex 1 (mTORC1) and FoxO1-mediated signaling pathways. SUMMARY mTORC1 suppresses lipolysis in adipose tissue and activates DNL in the liver, whereas FoxO1 has the opposite effect. Individual inputs of either mTORC1 or FoxO1 in the regulation of lipid metabolism may be difficult to evaluate because of the cross talk between these pathways.
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Affiliation(s)
- K.V. Kandror
- Boston University School of Medicine, Department of Biochemistry, K123D, 715 Albany Street, Boston, MA 02118, USA. Phone: 617-638-5049
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133
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134
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Insulin action and resistance in obesity and type 2 diabetes. Nat Med 2017; 23:804-814. [PMID: 28697184 DOI: 10.1038/nm.4350] [Citation(s) in RCA: 782] [Impact Index Per Article: 111.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/11/2017] [Indexed: 12/12/2022]
Abstract
Nutritional excess is a major forerunner of type 2 diabetes. It enhances the secretion of insulin, but attenuates insulin's metabolic actions in the liver, skeletal muscle and adipose tissue. However, conflicting evidence indicates a lack of knowledge of the timing of these events during the development of obesity and diabetes, pointing to a key gap in our understanding of metabolic disease. This Perspective reviews alternate viewpoints and recent results on the temporal and mechanistic connections between hyperinsulinemia, obesity and insulin resistance. Although much attention has addressed early steps in the insulin signaling cascade, insulin resistance in obesity seems to be largely elicited downstream of these steps. New findings also connect insulin resistance to extensive metabolic cross-talk between the liver, adipose tissue, pancreas and skeletal muscle. These and other advances over the past 5 years offer exciting opportunities and daunting challenges for the development of new therapeutic strategies for the treatment of type 2 diabetes.
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135
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Rojas-Gutierrez E, Muñoz-Arenas G, Treviño S, Espinosa B, Chavez R, Rojas K, Flores G, Díaz A, Guevara J. Alzheimer's disease and metabolic syndrome: A link from oxidative stress and inflammation to neurodegeneration. Synapse 2017. [PMID: 28650104 DOI: 10.1002/syn.21990] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and one of the most important causes of morbidity and mortality among the aging population. AD diagnosis is made post-mortem, and the two pathologic hallmarks, particularly evident in the end stages of the illness, are amyloid plaques and neurofibrillary tangles. Currently, there is no curative treatment for AD. Additionally, there is a strong relation between oxidative stress, metabolic syndrome, and AD. The high levels of circulating lipids and glucose imbalances amplify lipid peroxidation that gradually diminishes the antioxidant systems, causing high levels of oxidative metabolism that affects cell structure, leading to neuronal damage. Accumulating evidence suggests that AD is closely related to a dysfunction of both insulin signaling and glucose metabolism in the brain, leading to an insulin-resistant brain state. Four drugs are currently used for this pathology: Three FDA-approved cholinesterase inhibitors and one NMDA receptor antagonist. However, wide varieties of antioxidants are promissory to delay or prevent the symptoms of AD and may help in treating the disease. Therefore, therapeutic efforts to achieve attenuation of oxidative stress could be beneficial in AD treatment, attenuating Aβ-induced neurotoxicity and improve neurological outcomes in AD. The term inflammaging characterizes a widely accepted paradigm that aging is accompanied by a low-grade chronic up-regulation of certain pro-inflammatory responses in the absence of overt infection, and is a highly significant risk factor for both morbidity and mortality in the elderly.
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Affiliation(s)
- Eduardo Rojas-Gutierrez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Guadalupe Muñoz-Arenas
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, Mexico
| | - Samuel Treviño
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, Mexico
| | - Blanca Espinosa
- Departamento de Bioquímica, Instituto Nacional de Enfermedades Respiratorias-INER, Ciudad de México, Mexico
| | - Raúl Chavez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Karla Rojas
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Gonzalo Flores
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, Mexico
| | - Alfonso Díaz
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, Mexico
| | - Jorge Guevara
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
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Bolsoni-Lopes A, Alonso-Vale MIC. Lipolysis and lipases in white adipose tissue - An update. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2017; 59:335-42. [PMID: 26331321 DOI: 10.1590/2359-3997000000067] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/22/2015] [Indexed: 11/22/2022]
Abstract
Lipolysis is defined as the sequential hydrolysis of triacylglycerol (TAG) stored in cell lipid droplets. For many years, it was believed that hormone-sensitive lipase (HSL) and monoacylglycerol lipase (MGL) were the main enzymes catalyzing lipolysis in the white adipose tissue. Since the discovery of adipose triglyceride lipase (ATGL) in 2004, many studies were performed to investigate and characterize the actions of this lipase, as well as of other proteins and possible regulatory mechanisms involved, which reformulated the concept of lipolysis. Novel findings from these studies include the identification of lipolytic products as signaling molecules regulating important metabolic processes in many non-adipose tissues, unveiling a previously underestimated aspect of lipolysis. Thus, we present here an updated review of concepts and regulation of white adipocyte lipolysis with a special emphasis in its role in metabolism homeostasis and as a source of important signaling molecules.
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Affiliation(s)
- Andressa Bolsoni-Lopes
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, BR
| | - Maria Isabel C Alonso-Vale
- Departamento de Ciências Biológicas, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, SP, BR
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137
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AKT/PKB Signaling: Navigating the Network. Cell 2017; 169:381-405. [PMID: 28431241 DOI: 10.1016/j.cell.2017.04.001] [Citation(s) in RCA: 2344] [Impact Index Per Article: 334.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 03/29/2017] [Accepted: 03/31/2017] [Indexed: 12/14/2022]
Abstract
The Ser and Thr kinase AKT, also known as protein kinase B (PKB), was discovered 25 years ago and has been the focus of tens of thousands of studies in diverse fields of biology and medicine. There have been many advances in our knowledge of the upstream regulatory inputs into AKT, key multifunctional downstream signaling nodes (GSK3, FoxO, mTORC1), which greatly expand the functional repertoire of AKT, and the complex circuitry of this dynamically branching and looping signaling network that is ubiquitous to nearly every cell in our body. Mouse and human genetic studies have also revealed physiological roles for the AKT network in nearly every organ system. Our comprehension of AKT regulation and functions is particularly important given the consequences of AKT dysfunction in diverse pathological settings, including developmental and overgrowth syndromes, cancer, cardiovascular disease, insulin resistance and type 2 diabetes, inflammatory and autoimmune disorders, and neurological disorders. There has also been much progress in developing AKT-selective small molecule inhibitors. Improved understanding of the molecular wiring of the AKT signaling network continues to make an impact that cuts across most disciplines of the biomedical sciences.
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138
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Guilherme A, Pedersen DJ, Henchey E, Henriques FS, Danai LV, Shen Y, Yenilmez B, Jung D, Kim JK, Lodhi IJ, Semenkovich CF, Czech MP. Adipocyte lipid synthesis coupled to neuronal control of thermogenic programming. Mol Metab 2017; 6:781-796. [PMID: 28752043 PMCID: PMC5518709 DOI: 10.1016/j.molmet.2017.05.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 05/15/2017] [Accepted: 05/25/2017] [Indexed: 12/25/2022] Open
Abstract
Background The de novo biosynthesis of fatty acids (DNL) through fatty acid synthase (FASN) in adipocytes is exquisitely regulated by nutrients, hormones, fasting, and obesity in mice and humans. However, the functions of DNL in adipocyte biology and in the regulation of systemic glucose homeostasis are not fully understood. Methods & results Here we show adipocyte DNL controls crosstalk to localized sympathetic neurons that mediate expansion of beige/brite adipocytes within inguinal white adipose tissue (iWAT). Induced deletion of FASN in white and brown adipocytes of mature mice (iAdFASNKO mice) enhanced glucose tolerance, UCP1 expression, and cAMP signaling in iWAT. Consistent with induction of adipose sympathetic nerve activity, iAdFASNKO mice displayed markedly increased neuronal tyrosine hydroxylase (TH) and neuropeptide Y (NPY) content in iWAT. In contrast, brown adipose tissue (BAT) of iAdFASNKO mice showed no increase in TH or NPY, nor did FASN deletion selectively in brown adipocytes (UCP1-FASNKO mice) cause these effects in iWAT. Conclusions These results demonstrate that downregulation of fatty acid synthesis via FASN depletion in white adipocytes of mature mice can stimulate neuronal signaling to control thermogenic programming in iWAT. Inducible deletion of FASN in white adipocytes of mature mice enhances browning of iWAT. Inducible deletion of white adipocyte FASN in mature obese mice improves glucose tolerance. Loss of FASN in white adipocytes enhances sympathetic nerve outflow in iWAT. Crosstalk between adipocyte fat metabolism and neuronal stimulation of adipose tissue is proposed.
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Affiliation(s)
- Adilson Guilherme
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - David J Pedersen
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Elizabeth Henchey
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Felipe S Henriques
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Laura V Danai
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Yuefei Shen
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Batuhan Yenilmez
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - DaeYoung Jung
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jason K Kim
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Irfan J Lodhi
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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139
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Zhan Y, Xie P, Li D, Li L, Chen J, An W, Zhang L, Zhang C. Deficiency of CKIP-1 aggravates high-fat diet-induced fatty liver in mice. Exp Cell Res 2017; 355:40-46. [PMID: 28351752 DOI: 10.1016/j.yexcr.2017.03.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/08/2017] [Accepted: 03/16/2017] [Indexed: 01/07/2023]
Abstract
Casein kinase 2 interacting protein-1(CKIP-1) is widely expressed in a variety of tissues and cells, and plays an important role in various critical cellular and physiological processes including cell growth, apoptosis, differentiation, cytoskeleton and bone formation. Here, we found: (1) CKIP-1 deficient mice exhibited increased body weight, liver weight, number and size of lipid droplets, and TG content comparing with WT mice after being exposed to high fat diet (HFD); (2) the levels of serum insulin, liver glycogen, phosphorylated C-Jun-N-terminal kinase-1 (pJNK1) and phosphorylated insulin receptor substrate -1(pIRS1) in CKIP-1-/- mice were higher than those of WT mice; (3) CKIP-1 interacted with JNK1 in vitro. Our results indicate that CKIP-1 deficiency in mice aggravates HFD-induced fatty liver by upregulating JNK1 phosphorylation and further upregulating IRS-1 phosphorylation and RI.
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Affiliation(s)
- Yutao Zhan
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Ping Xie
- Physical Examination Centre, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Dongnian Li
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory of Cancer & Metastasis Research, Capital Medical University, Beijing 100069, China
| | - Li Li
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Jing Chen
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Wei An
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - Lingqiang Zhang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Chuan Zhang
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China.
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140
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Kon K, Ikejima K, Morinaga M, Kusama H, Arai K, Aoyama T, Uchiyama A, Yamashina S, Watanabe S. L-carnitine prevents metabolic steatohepatitis in obese diabetic KK-A y mice. Hepatol Res 2017; 47:E44-E54. [PMID: 27062266 DOI: 10.1111/hepr.12720] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/03/2016] [Accepted: 04/05/2016] [Indexed: 02/08/2023]
Abstract
AIM Pharmacological treatment for metabolic syndrome-related non-alcoholic steatohepatitis has not been established. We investigated the effect of L-carnitine, an essential substance for β-oxidation, on metabolic steatohepatitis in mice. METHODS Male KK-Ay mice were fed a high-fat diet (HFD) for 8 weeks, with supplementation of L-carnitine (1.25 mg/mL) in drinking water for the latter 4 weeks. RESULTS Serum total carnitine levels were decreased following HFD feeding, whereas the levels were reversed almost completely by L-carnitine supplementation. In mice given L-carnitine, exacerbation of hepatic steatosis and hepatocyte apoptosis was markedly prevented even though HFD feeding was continued. Body weight gain, as well as hyperlipidemia, hyperglycemia, and hyperinsulinemia, following HFD feeding were also significantly prevented in mice given L-carnitine. High-fat diet feeding elevated hepatic expression levels of carnitine palmitoyltransferase 1A mRNA; however, production of β-hydroxybutyrate in the liver was not affected by HFD alone. In contrast, L-carnitine treatment significantly increased hepatic β-hydroxybutyrate contents in HFD-fed mice. L-carnitine also blunted HFD induction in sterol regulatory element binding protein-1c mRNA in the liver. Furthermore, L-carnitine inhibited HFD-induced serine phosphorylation of insulin receptor substrate-1 in the liver. L-carnitine decreased hepatic free fatty acid content in 1 week, with morphological improvement of swollen mitochondria in hepatocytes, and increases in hepatic adenosine 5'-triphosphate content. CONCLUSIONS L-carnitine ameliorates steatohepatitis in KK-Ay mice fed an HFD, most likely through facilitating mitochondrial β-oxidation, normalizing insulin signals, and inhibiting de novo lipogenesis in the liver. It is therefore postulated that supplementation of L-carnitine is a promising approach for prevention and treatment of metabolic syndrome-related non-alcoholic steatohepatitis.
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Affiliation(s)
- Kazuyoshi Kon
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Kenichi Ikejima
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Maki Morinaga
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Hiromi Kusama
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Kumiko Arai
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Tomonori Aoyama
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Akira Uchiyama
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Shunhei Yamashina
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
| | - Sumio Watanabe
- Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
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141
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Templeman NM, Skovsø S, Page MM, Lim GE, Johnson JD. A causal role for hyperinsulinemia in obesity. J Endocrinol 2017; 232:R173-R183. [PMID: 28052999 DOI: 10.1530/joe-16-0449] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/03/2017] [Indexed: 12/13/2022]
Abstract
Insulin modulates the biochemical pathways controlling lipid uptake, lipolysis and lipogenesis at multiple levels. Elevated insulin levels are associated with obesity, and conversely, dietary and pharmacological manipulations that reduce insulin have occasionally been reported to cause weight loss. However, the causal role of insulin hypersecretion in the development of mammalian obesity remained controversial in the absence of direct loss-of-function experiments. Here, we discuss theoretical considerations around the causal role of excess insulin for obesity, as well as recent studies employing mice that are genetically incapable of the rapid and sustained hyperinsulinemia that normally accompanies a high-fat diet. We also discuss new evidence demonstrating that modest reductions in circulating insulin prevent weight gain, with sustained effects that can persist after insulin levels normalize. Importantly, evidence from long-term studies reveals that a modest reduction in circulating insulin is not associated with impaired glucose homeostasis, meaning that body weight and lipid homeostasis are actually more sensitive to small changes in circulating insulin than glucose homeostasis in these models. Collectively, the evidence from new studies on genetic loss-of-function models forces a re-evaluation of current paradigms related to obesity, insulin resistance and diabetes. The potential for translation of these findings to humans is briefly discussed.
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Affiliation(s)
- Nicole M Templeman
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Søs Skovsø
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Melissa M Page
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gareth E Lim
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - James D Johnson
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Institute for Personalized Therapeutic NutritionVancouver, British Columbia, Canada
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142
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Halm ST, Bottomley MA, Almutairi MM, Di Fulvio M, Halm DR. Survival and growth of C57BL/6J mice lacking the BK channel, Kcnma1: lower adult body weight occurs together with higher body fat. Physiol Rep 2017; 5:5/4/e13137. [PMID: 28242822 PMCID: PMC5328773 DOI: 10.14814/phy2.13137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/23/2016] [Accepted: 01/02/2017] [Indexed: 11/29/2022] Open
Abstract
Big conductance potassium (BK) channels contribute to K+ flow and electrical behavior in many cell types. Mice made null for the gene (Kcnma1) producing the BK channel (BKKO) exhibit numerous deficits in physiological functions. Breeding mice lacking a single allele of Kcnma1 (C57BL/6J background) had litter sizes of approximately eight pups. For the period of maternal care (P0–P21), pup deaths peaked at P1 with a second less severe interval of death peaking near P13. Early deaths were twice as likely during a 20‐month period of building construction compared with the quiescent period after cessation of construction. Births during construction were not consistent with Mendelian predictions indicating the likelihood of a specific disadvantage induced by this environmental stressor. Later BKKO pup deaths (~P13) also were more numerous than Mendelian expectations. After weaning, weight gain was slower for BKKO mice compared with wild‐type littermates: 5 g less for male BKKO mice and 4 g less for female BKKO mice. Body composition determined by quantitative magnetic resonance indicated a higher fat proportion for wild‐type female mice compared with males, as well as a higher hydration ratio. Both male and female BKKO mice showed higher fat proportions than wild‐type, with female BKKO mice exhibiting greater variation. Together, these results indicate that BKKO mice suffered disadvantages that lead to prenatal and perinatal death. A metabolic difference likely related to glucose handling led to the smaller body size and distinct composition for BKKO mice, suggesting a diversion of energy supplies from growth to fat storage.
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Affiliation(s)
- Susan T Halm
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Michael A Bottomley
- Department of Mathematics and Statistics, Statistical Consulting Center, Wright State University, Dayton, Ohio
| | - Mohammed M Almutairi
- Department of Pharmacology and Toxicology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Maurico Di Fulvio
- Department of Pharmacology and Toxicology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Dan R Halm
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
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143
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FAK signalling controls insulin sensitivity through regulation of adipocyte survival. Nat Commun 2017; 8:14360. [PMID: 28165007 PMCID: PMC5303880 DOI: 10.1038/ncomms14360] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 12/21/2016] [Indexed: 12/30/2022] Open
Abstract
Focal adhesion kinase (FAK) plays a central role in integrin signalling, which regulates growth and survival of tumours. Here we show that FAK protein levels are increased in adipose tissue of insulin-resistant obese mice and humans. Disruption of adipocyte FAK in mice or in 3T3 L1 cells decreases adipocyte survival. Adipocyte-specific FAK knockout mice display impaired adipose tissue expansion and insulin resistance on prolonged metabolic stress from a high-fat diet or when crossed on an obese db/db or ob/ob genetic background. Treatment of these mice with a PPARγ agonist does not restore adiposity or improve insulin sensitivity. In contrast, inhibition of apoptosis, either genetically or pharmacologically, attenuates adipocyte death, restores normal adiposity and improves insulin sensitivity. Together, these results demonstrate that FAK is required for adipocyte survival and maintenance of insulin sensitivity, particularly in the context of adipose tissue expansion as a result of caloric excess. The kinase FAK is important for integrin signalling and promotes cell survival. Here, the authors demonstrate FAK regulates adipocyte survival, and is particularly important for maintaining insulin sensitivity during adipose tissue expansion in the context of a calorie-rich diet.
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144
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Flachs P, Adamcova K, Zouhar P, Marques C, Janovska P, Viegas I, Jones JG, Bardova K, Svobodova M, Hansikova J, Kuda O, Rossmeisl M, Liisberg U, Borkowska AG, Kristiansen K, Madsen L, Kopecky J. Induction of lipogenesis in white fat during cold exposure in mice: link to lean phenotype. Int J Obes (Lond) 2016; 41:372-380. [PMID: 28008171 DOI: 10.1038/ijo.2016.228] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/10/2016] [Accepted: 11/24/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND/OBJECTIVE Futile substrate cycling based on lipolytic release of fatty acids (FA) from intracellular triacylglycerols (TAG) and their re-esterification (TAG/FA cycling), as well as de novo FA synthesis (de novo lipogenesis (DNL)), represent the core energy-consuming biochemical activities of white adipose tissue (WAT). We aimed to characterize their roles in cold-induced thermogenesis and energy homeostasis. METHODS Male obesity-resistant A/J and obesity-prone C57BL/6J mice maintained at 30 °C were exposed to 6 °C for 2 or 7 days. In epididymal WAT (eWAT), TAG synthesis and DNL were determined using in vivo 2H incorporation from 2H2O into tissue TAG and nuclear magnetic resonance spectroscopy. Quantitative real-time-PCR and/or immunohistochemistry and western blotting were used to determine the expression of selected genes and proteins in WAT and liver. RESULTS The mass of WAT depots declined during cold exposure (CE). Plasma levels of TAG and non-esterified FA were decreased by day 2 but tended to normalize by day 7 of CE. TAG synthesis (reflecting TAG/FA cycle activity) gradually increased during CE. DNL decreased by day 2 of CE but increased several fold over the control values by day 7. Expression of genes involved in lipolysis, glyceroneogenesis, FA re-esterification, FA oxidation and mitochondrial biogenesis in eWAT was induced during CE. All these changes were more pronounced in obesity-resistant A/J than in B6 mice and occurred in the absence of uncoupling protein 1 in eWAT. Expression of markers of glyceroneogenesis in eWAT correlated negatively with hepatic FA synthesis by day 7 in both strains. Leptin and fibroblast growth factor 21 plasma levels were differentially affected by CE in the two mouse strains. CONCLUSIONS Our results indicate integrated involvement of (i) TAG/FA cycling and DNL in WAT, and (ii) hepatic very-low-density lipoprotein-TAG synthesis in the control of blood lipid levels and provision of FA fuels for thermogenesis in cold. They suggest that lipogenesis in WAT contributes to a lean phenotype.
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Affiliation(s)
- P Flachs
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - K Adamcova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - P Zouhar
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - C Marques
- Centre for Neuroscience and Cell Biology, University of Coimbra, Cantanhede, Portugal
| | - P Janovska
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - I Viegas
- Centre for Neuroscience and Cell Biology, University of Coimbra, Cantanhede, Portugal
| | - J G Jones
- Centre for Neuroscience and Cell Biology, University of Coimbra, Cantanhede, Portugal
| | - K Bardova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - M Svobodova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - J Hansikova
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - O Kuda
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - M Rossmeisl
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - U Liisberg
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,National Institute of Nutrition and Seafood Research, Bergen, Norway
| | - A G Borkowska
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - K Kristiansen
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,BGI-Shenzhen, Shenzhen, China
| | - L Madsen
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,National Institute of Nutrition and Seafood Research, Bergen, Norway
| | - J Kopecky
- Department of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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145
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Zhou X, Zhu J, Bao Z, Shang Z, Wang T, Song J, Sun J, Li W, Adelusi TI, Wang Y, Lv D, Lu Q, Yin X. A variation in KCNQ1 gene is associated with repaglinide efficacy on insulin resistance in Chinese Type 2 Diabetes Mellitus Patients. Sci Rep 2016; 6:37293. [PMID: 27857189 PMCID: PMC5114551 DOI: 10.1038/srep37293] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 10/28/2016] [Indexed: 01/19/2023] Open
Abstract
Repaglinide is an insulin secretagogue that often exhibits considerable interindividual variability in therapeutic efficacy. The current study was designed to investigate the impact of KCNQ1 genetic polymorphism on the efficacy of repaglinide and furthermore to identify the potential mechanism of action in patients with type 2 diabetes. A total of 305 patients and 200 healthy subjects were genotyped for the KCNQ1 rs2237892 polymorphism, and 82 patients with T2DM were randomized for the oral administration of repaglinide for 8 weeks. HepG2 cells were incubated with repaglinide in the absence or presence of a KCNQ1 inhibitor or the pcDNA3.1-hKCNQ1 plasmid, after which the levels of Akt, IRS-2 and PI(3)K were determined. Our data showed that repaglinide significantly decreased HOMA-IR in patients with T2DM. Furthermore, the level of HOMA-IR was significantly reduced in those patients with CT or TT genotypes than CC homozygotes. The KCNQ1 inhibitor enhanced repaglinide efficacy on insulin resistance, with IRS-2/PI(3)K/Akt signaling being up-regulated markedly. As in our clinical experiment, these data strongly suggest that KCNQ1 genetic polymorphism influences repaglinide response due to the pivotal role of KCNQ1 in regulating insulin resistance through the IRS-2/PI(3)K/Akt signaling pathway. This study was registered in the Chinese Clinical Trial Register on May 14, 2013. (No. ChiCTR-CCC13003536).
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Affiliation(s)
- Xueyan Zhou
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Jing Zhu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Zejun Bao
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Zhenhai Shang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China.,Department of Pharmacy, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Tao Wang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China.,Department of Pharmacy, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Jinfang Song
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Juan Sun
- Department of Endocrinology, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Wei Li
- Department of Endocrinology, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Temitope Isaac Adelusi
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Yan Wang
- Department of Pharmacy, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Dongmei Lv
- Department of Pharmacy, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Qian Lu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Xiaoxing Yin
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, People's Republic of China
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146
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Cederquist CT, Lentucci C, Martinez-Calejman C, Hayashi V, Orofino J, Guertin D, Fried SK, Lee MJ, Cardamone MD, Perissi V. Systemic insulin sensitivity is regulated by GPS2 inhibition of AKT ubiquitination and activation in adipose tissue. Mol Metab 2016; 6:125-137. [PMID: 28123943 PMCID: PMC5220281 DOI: 10.1016/j.molmet.2016.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 10/20/2016] [Accepted: 10/24/2016] [Indexed: 02/06/2023] Open
Abstract
Objective Insulin signaling plays a unique role in the regulation of energy homeostasis and the impairment of insulin action is associated with altered lipid metabolism, obesity, and Type 2 Diabetes. The main aim of this study was to provide further insight into the regulatory mechanisms governing the insulin signaling pathway by investigating the role of non-proteolytic ubiquitination in insulin-mediated activation of AKT. Methods The molecular mechanism of AKT regulation through ubiquitination is first dissected in vitro in 3T3-L1 preadipocytes and then validated in vivo using mice with adipo-specific deletion of GPS2, an endogenous inhibitor of Ubc13 activity (GPS2-AKO mice). Results Our results indicate that K63 ubiquitination is a critical component of AKT activation in the insulin signaling pathway and that counter-regulation of this step is provided by GPS2 preventing AKT ubiquitination through inhibition of Ubc13 enzymatic activity. Removal of this negative checkpoint, through GPS2 downregulation or genetic deletion, results in sustained activation of insulin signaling both in vitro and in vivo. As a result, the balance between lipid accumulation and utilization is shifted toward storage in the adipose tissue and GPS2-AKO mice become obese under normal laboratory chow diet. However, the adipose tissue of GPS2-AKO mice is not inflamed, the levels of circulating adiponectin are elevated, and systemic insulin sensitivity is overall improved. Conclusions Our findings characterize a novel layer of regulation of the insulin signaling pathway based on non-proteolytic ubiquitination of AKT and define GPS2 as a previously unrecognized component of the insulin signaling cascade. In accordance with this role, we have shown that GPS2 presence in adipocytes modulates systemic metabolism by restricting the activation of insulin signaling during the fasted state, whereas in absence of GPS2, the adipose tissue is more efficient at lipid storage, and obesity becomes uncoupled from inflammation and insulin resistance. Ubc13-mediated ubiquitination of AKT is required for activation of the insulin signaling pathway. GPS2 regulates insulin signaling by inhibiting AKT ubiquitination and activation. Adipo-specific deletion of GPS2 results in increased adiposity and altered lipid flux in the adipocytes. GPS2-AKO mice have higher levels of circulating adiponectin and are insulin sensitive despite being obese.
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Affiliation(s)
- Carly T Cederquist
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St, Boston, MA 02118, USA
| | - Claudia Lentucci
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St, Boston, MA 02118, USA
| | - Camila Martinez-Calejman
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation St, Worcester, MA 01605, USA
| | - Vanessa Hayashi
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St, Boston, MA 02118, USA
| | - Joseph Orofino
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St, Boston, MA 02118, USA
| | - David Guertin
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation St, Worcester, MA 01605, USA
| | - Susan K Fried
- Diabetes Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, 1 Gustav Levy Place, New York, NY 10029, USA
| | - Mi-Jeong Lee
- Department of Medicine, Boston University School of Medicine, 72 E. Concord St, Boston, MA 02118, USA
| | - M Dafne Cardamone
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St, Boston, MA 02118, USA
| | - Valentina Perissi
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St, Boston, MA 02118, USA.
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147
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Jacobsen RG, Mazloumi Gavgani F, Mellgren G, Lewis AE. DNA Topoisomerase IIα contributes to the early steps of adipogenesis in 3T3-L1 cells. Cell Signal 2016; 28:1593-603. [DOI: 10.1016/j.cellsig.2016.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/07/2016] [Indexed: 01/03/2023]
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148
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Heimann E, Nyman M, Pålbrink AK, Lindkvist-Petersson K, Degerman E. Branched short-chain fatty acids modulate glucose and lipid metabolism in primary adipocytes. Adipocyte 2016; 5:359-368. [PMID: 27994949 PMCID: PMC5160390 DOI: 10.1080/21623945.2016.1252011] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/14/2016] [Accepted: 10/18/2016] [Indexed: 02/08/2023] Open
Abstract
Short-chain fatty acids (SCFAs), e.g. acetic acid, propionic acid and butyric acid, generated through colonic fermentation of dietary fibers, have been shown to reach the systemic circulation at micromolar concentrations. Moreover, SCFAs have been conferred anti-obesity properties in both animal models and human subjects. Branched SCFAs (BSCFAs), e.g., isobutyric and isovaleric acid, are generated by fermentation of branched amino acids, generated from undigested protein reaching colon. However, BSCFAs have been sparsely investigated when referring to effects on energy metabolism. Here we primarily investigate the effects of isobutyric acid and isovaleric acid on glucose and lipid metabolism in primary rat and human adipocytes. BSCFAs inhibited both cAMP-mediated lipolysis and insulin-stimulated de novo lipogenesis at 10 mM, whereas isobutyric acid potentiated insulin-stimulated glucose uptake by all concentrations (1, 3 and 10 mM) in rat adipocytes. For human adipocytes, only SCFAs inhibited lipolysis at 10 mM. In both in vitro models, BSCFAs and SCFAs reduced phosphorylation of hormone sensitive lipase, a rate limiting enzyme in lipolysis. In addition, BSCFAs and SCFAs, in contrast to insulin, inhibited lipolysis in the presence of wortmannin, a phosphatidylinositide 3-kinase inhibitor and OPC3911, a phosphodiesterase 3 inhibitor in rat adipocytes. Furthermore, BSCFAs and SCFAs reduced insulin-mediated phosphorylation of protein kinase B. To conclude, BSCFAs have effects on adipocyte lipid and glucose metabolism that can contribute to improved insulin sensitivity in individuals with disturbed metabolism.
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149
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Levine JA, Kaihara KA, Layden BT, Wicksteed B. Long-term activation of PKA in β-cells provides sustained improvement to glucose control, insulin sensitivity and body weight. Islets 2016; 8:125-34. [PMID: 27340937 PMCID: PMC5029204 DOI: 10.1080/19382014.2016.1198457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Type 2 diabetes is associated with obesity, insulin resistance and β-cell failure. Therapeutic aims are to reduce adiposity, improve insulin sensitivity and enhance β-cell function. However, it has been proposed that chronically increasing insulin release leads to β-cell exhaustion and failure. We previously developed mice to have increased activity of the cAMP-dependent protein kinase (PKA), specifically in β-cells (β-caPKA mice). β-caPKA mice have enhanced acute phase insulin release, which is the primary determinant of the efficacy of glucose clearance. Here these mice were used to determine the sustainability of enhanced insulin secretion, and to characterize peripheral effects of enhanced β-cell function. Increased PKA activity was induced by tamoxifen administration at 10 weeks of age. Male mice were aged to 12 months of age and female mice to 16 months. Glucose control in both male and female β-caPKA mice was significantly improved relative to littermate controls with ad libitum feeding, upon refeeding after fasting, and in glucose tolerance tests. In female mice insulin release was both greater and more rapid than in controls. Female mice were more insulin sensitive than controls. Male and female β-caPKA mice had lower body weights than controls. DEXA analysis of male mice revealed that this was due to reduced adiposity and not due to changes in lean body mass. This study indicates that targeting β-cells to enhance insulin release is sustainable, maintains insulin sensitivity and reduces body weight. These data identify β-cell PKA activity as a novel target for obesity therapies.
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Affiliation(s)
- Joshua A. Levine
- Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Kelly A. Kaihara
- Committee for Molecular Metabolism and Nutrition, The University of Chicago, Chicago, IL, USA
- Bio-Rad Laboratories, Hercules, CA, USA
| | - Brian T. Layden
- Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA
| | - Barton Wicksteed
- Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Committee for Molecular Metabolism and Nutrition, The University of Chicago, Chicago, IL, USA
- CONTACT Barton Wicksteed Division of Endocrinology, Metabolism and Molecular Medicine, Tarry Building 15-735 300 East Superior St., Chicago, IL 60611-3008, USA
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150
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Garessus EDG, de Mutsert R, Visser AW, Rosendaal FR, Kloppenburg M. No association between impaired glucose metabolism and osteoarthritis. Osteoarthritis Cartilage 2016; 24:1541-7. [PMID: 27084351 DOI: 10.1016/j.joca.2016.04.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/21/2016] [Accepted: 04/04/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the association between markers of glucose metabolism and hand and knee osteoarthritis (OA). METHODS This is a cross-sectional analysis of baseline measurements of the Netherlands Epidemiology of Obesity (NEO) study, a population-based prospective cohort study. Fasting glucose, insulin and glycated hemoglobulin A1c (HbA1c) concentrations were measured, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was calculated and clinical OA was defined following the American College of Rheumatology (ACR) criteria. After exclusion of participants on glucose-lowering drugs, odds ratios (ORs) with 95% confidence intervals (CIs) for either hand, knee or both hand and knee OA were calculated (no OA as reference), as a function of each marker of glucose metabolism, with logistic regression analyses. Models were adjusted for age, ethnicity, education, height, weight and total body fat, and stratified by sex. RESULTS In 6197 participants (age 45-65 years, 56% women, mean body mass index (BMI) 26 kg/m(2)), prevalences of hand OA, knee OA or both were 7%, 10% or 4%, respectively. In men, the adjusted OR (95%CI) for hand OA was 1.18 (1.01-1.39) per standard deviation (SD) increase in plasma glucose (0.85 mmol/L). There were no further associations of glucose, HbA1c, insulin and HOMA-IR with the different types of OA, neither in men nor in women. CONCLUSION An impaired glucose metabolism does not seem be related to OA. In men, an association was observed for fasting glucose concentrations and hand OA. Future studies should investigate the presence of sex differences in the pathogenesis of hand OA.
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Affiliation(s)
- E D G Garessus
- Department of Rheumatology, Leiden University Medical Center, C1-R, P.O. Box 9600, Leiden 2300 RC, The Netherlands.
| | - R de Mutsert
- Department of Clinical Epidemiology, Leiden University Medical Center, C7-P, P.O. Box 9600, Leiden 2300 RC, The Netherlands.
| | - A W Visser
- Department of Rheumatology, Leiden University Medical Center, C1-R, P.O. Box 9600, Leiden 2300 RC, The Netherlands.
| | - F R Rosendaal
- Department of Clinical Epidemiology, Leiden University Medical Center, C7-P, P.O. Box 9600, Leiden 2300 RC, The Netherlands; Department of Thrombosis and Hemostasis, Leiden University Medical Center, C7-P, P.O. Box 9600, Leiden 2300 RC, The Netherlands.
| | - M Kloppenburg
- Department of Rheumatology, Leiden University Medical Center, C1-R, P.O. Box 9600, Leiden 2300 RC, The Netherlands; Department of Clinical Epidemiology, Leiden University Medical Center, C7-P, P.O. Box 9600, Leiden 2300 RC, The Netherlands.
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