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Song Y, Wei D, Raza SHA, Zhao Y, Jiang C, Song X, Wu H, Wang X, Luoreng Z, Ma Y. Research progress of intramuscular fat formation based on co-culture. Anim Biotechnol 2023; 34:3216-3236. [PMID: 36200856 DOI: 10.1080/10495398.2022.2127410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Intramuscular fat (IMF) is closely related to the meat quality of livestock and poultry. As a new cell culture technique in vitro, cell co-culture has been gradually applied to the related research of IMF formation because it can simulate the changes of microenvironment in vivo during the process of IMF cell formation. In the co-culture model, in addition to studying the effects of skeletal muscle cells on the proliferation and differentiation of IMF, we can also consider the role of many secretion factors in the formation of IMF, thus making the cell research in vitro closer to the real level in vivo. This paper reviewed the generation and origin of IMF, summarized the existing co-culture methods and systems, and discussed the advantages and disadvantages of each method as well as the challenges faced in the establishment of the system, with emphasis on the current status of research on the formation of IMF for human and animal based on co-culture technology.
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Affiliation(s)
- Yaping Song
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | - Dawei Wei
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | | | - Yiang Zhao
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | - Chao Jiang
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | - Xiaoyu Song
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | - Hao Wu
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | - Xingping Wang
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | - Zhuoma Luoreng
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
| | - Yun Ma
- School of Agriculture, Ningxia University, Ningxia Yin Chuan, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia University, Ningxia Yinchuan, China
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Ramser A, Dridi S. Hormonal regulation of visfatin and adiponectin system in quail muscle cells. Comp Biochem Physiol A Mol Integr Physiol 2023; 281:111425. [PMID: 37044369 DOI: 10.1016/j.cbpa.2023.111425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/08/2023] [Accepted: 04/08/2023] [Indexed: 04/14/2023]
Abstract
Visfatin and adiponectin are two adipokines known to regulate energy homeostasis and stress response within different peripheral tissues. Their role and regulation in highly metabolically active tissue such as the muscle is of particular interest. As modern poultry exhibit insulin resistance, obesity, and hyperglycemia along with a lack of insight into the regulation of these avian adipokines, we undertook the present work to determine the regulation of visfatin and adiponectin system by cytokines and obesity-related hormones in a relevant in vitro model of avian muscle, quail muscle (QM7) cells. Cells were treated with pro-inflammatory cytokine IL-6 (5 and 10 ng/mL) and TNFα (5 and 10 ng/mL), as well as leptin (10 and 100 ng/mL) and both orexin-A and orexin-B (ORX-A/B) (5 and 10 ng/mL). Results showed significant increases in visfatin mRNA abundance under both cytokines (IL-6 and TNFα), and down regulation with ORX-B treatment. Adiponectin expression was also upregulated by pro-inflammatory cytokines (IL-6 and TNFα), but down regulated by leptin, ORX-A, and ORXB. High doses of IL-6 and TNFα up regulated the expression of adiponectin receptors AdipoR1 and AdipoR2, respectively. Leptin and orexin treatments also down regulated both AdipoR1 and AdipoR2 expression. Taken together, this is the first report showing a direct response of visfatin and the adiponectin system to pro-inflammatory and obesity-related hormones in avian muscle cells.
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Affiliation(s)
- Alison Ramser
- University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, AR 72701, USA
| | - Sami Dridi
- University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, AR 72701, USA.
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3
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Ievleva KD, Danusevich IN, Suturina LV. [Role of leptin and nuclear receptor PPARγ in PCOS pathogenesis]. ACTA ACUST UNITED AC 2020; 66:74-80. [PMID: 33481370 DOI: 10.14341/probl12620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/18/2020] [Accepted: 12/06/2020] [Indexed: 11/06/2022]
Abstract
Polycystic ovary syndrome (PCOS) is the most common cause of female endocrine infertility. Insulin resistanсе is supposed to be one of the essential factors of this disease pathways. At the same time, the mechanisms of PCOS development in insulin-resistant patients have not been completely established. Leptin and Peroxisome Proliferator-Activated Receptor γ(PPARγ) are involved in carbohydrate metabolism and reproduction function regulation. It indicates that leptin and PPARγ possibly play a role in the pathways of PCOS. This article is a review of publications on this issue. The purpose of this review was to systematize the available information on the molecular mechanisms that determine the role of leptin and PPARγ in the development of PCOS. The literature search was carried out from 04/05/2020 to 05/17/2020 using the scientific literature databases: NCBI PubMed (foreign sources) and Cyberleninka (domestic sources). We analyzed publications for the period 1990-2020.The review presents the current understanding of the possible role of leptin and PPARγ in the regulation of endocrine, immune systems, and reproductive function, as well as in the development of PCOS. Currently, no studies cover the mechanisms of interaction between leptin and PPARγ in the pathways of this syndrome. The available studies indicating the individual contribution and association of leptin and PPARγ with PCOS are conflicting and have many limitations. Therefore, more studies of direct and indirect interaction of leptin and PPARγ, as well as their role in PCOS pathways, are needed.
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Affiliation(s)
- K D Ievleva
- Scientific Сentre for Family Health and Human Reproduction Problems
| | - I N Danusevich
- Scientific Сentre for Family Health and Human Reproduction Problems
| | - L V Suturina
- Scientific Сentre for Family Health and Human Reproduction Problems
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Frühbeck G, Catalán V, Rodríguez A, Ramírez B, Becerril S, Portincasa P, Gómez-Ambrosi J. Normalization of adiponectin concentrations by leptin replacement in ob/ob mice is accompanied by reductions in systemic oxidative stress and inflammation. Sci Rep 2017; 7:2752. [PMID: 28584304 PMCID: PMC5459809 DOI: 10.1038/s41598-017-02848-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/18/2017] [Indexed: 12/13/2022] Open
Abstract
The circulating concentrations of adiponectin, an antidiabetic adipokine, have been shown to be reduced in obesity, in relation to an increase in inflammation. The aim of the present work was to assess the effect of leptin replacement on adiponectin levels and expression as well as on markers of oxidative stress and inflammation in leptin-deficient ob/ob mice. Twelve-week-old male mice (n = 7–10 per group) were treated with either saline (wild type and ob/ob mice) or leptin (ob/ob mice) for 18 days. A third group of ob/ob mice was treated with saline and pair-fed to the amount of food consumed by the leptin-treated group. Leptin replacement restored values of adiponectin (P < 0.001), reduced circulating 8-isoprostane and serum amyloid A (SAA) levels (P < 0.05 for both), and significantly downregulated the increased gene expression of osteopontin (Spp1, P < 0.05), Saa3 (P < 0.05), Cd68 (P < 0.01), Il6 (P < 0.01) and NADPH oxidase (Nox1 and Nox2, P < 0.01) in the perirenal WAT and Spp1 (P < 0.05) in the liver of ob/ob mice. In cultured adipocytes from ob/ob mice, leptin increased (P < 0.05) the mRNA expression and secretion of adiponectin. We concluded that circulating concentrations of adiponectin are positively regulated by leptin and ameliorate obesity-associated oxidative stress and inflammation in mice.
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Affiliation(s)
- Gema Frühbeck
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Pamplona, Spain.,Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain.,Department of Endocrinology & Nutrition, Clínica Universidad de Navarra, Pamplona, Spain
| | - Victoria Catalán
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Pamplona, Spain.,Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Amaia Rodríguez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Pamplona, Spain.,Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Beatriz Ramírez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Pamplona, Spain.,Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Sara Becerril
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Pamplona, Spain.,Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Piero Portincasa
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, Policlinico Hospital, Bari, Italy
| | - Javier Gómez-Ambrosi
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain. .,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Pamplona, Spain. .,Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain.
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Pierard M, Conotte S, Tassin A, Boutry S, Uzureau P, Boudjeltia KZ, Legrand A. Interactions of exercise training and high-fat diet on adiponectin forms and muscle receptors in mice. Nutr Metab (Lond) 2016; 13:75. [PMID: 27822289 PMCID: PMC5094086 DOI: 10.1186/s12986-016-0138-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/21/2016] [Indexed: 01/08/2023] Open
Abstract
Background Metabolic syndrome (MetS) is characterized by systemic disturbances that increase cardiovascular risk. Adiponectin (Ad) exhibits a cardioprotective function because of its anti-inflammatory and anti-atherosclerotic properties. In the bloodstream, this adipocytokine circulates on multimers (Admer), among which high molecular weight (HMW) are the most active forms. Because alterations of Ad plasmatic levels, Admer distribution and receptor (AdipoR) expression have been described in murine models and obese patients, strategies that aim to enhance Ad production or its effect on target tissues are the subject of intense investigations. While exercise training is well known to be beneficial for reducing cardiovascular risk, the contribution of Ad is still controversial. Our aim was to evaluate the effect of exercise training on Ad production, Admer distribution and AdipoR muscle expression in a murine model of MetS. Methods At 6 weeks of age, mice were submitted to a standard (SF) or high-fat high-sugar (HF) diet for 10 weeks. After 2 weeks, the SF- and HF-fed animals were randomly assigned to a training program (SFT, HFT) or not (SFC, HFC). The trained groups were submitted to sessions of running on a treadmill 5 days a week. Results and conclusions The HF mice presented the key problems associated with MetS (increased caloric intake, body weight, glycemia and fat mass), a change in Admer distribution in favor of the less-active forms and increased AdipoR2 expression in muscle. In contrast, exercise training reversed some of the adverse effects of a HF diet (increased glucose tolerance, better caloric intake control) without any modifications in Ad production and Admer distribution. However, increased AdipoR1 muscle expression was observed in trained mice, but this effect was hampered by HF diet. These data corroborate a recent hypothesis suggesting a functional divergence between AdipoR1 and AdipoR2, with AdipoR1 having the predominant protective action on metabolic function. Electronic supplementary material The online version of this article (doi:10.1186/s12986-016-0138-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mélany Pierard
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Stéphanie Conotte
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Alexandra Tassin
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Sébastien Boutry
- Department of General, Organic and Biomedical Chemistry, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium.,Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Pierrick Uzureau
- Experimental Medicine Laboratory, Free University of Brussels, CHU de Charleroi, Belgium
| | | | - Alexandre Legrand
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
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Differential effects of leptin on adiponectin expression with weight gain versus obesity. Int J Obes (Lond) 2015; 40:266-74. [PMID: 26374448 PMCID: PMC4747836 DOI: 10.1038/ijo.2015.181] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 08/12/2015] [Accepted: 08/19/2015] [Indexed: 12/15/2022]
Abstract
Background/Objective Adiponectin exerts beneficial effects by reducing inflammation, and improving lipid metabolism and insulin-sensitivity. Although adiponectin is lower in obese individuals, whether weight gain reduces adiponectin expression in humans is controversial. We sought to investigate the role of weight gain, and consequent changes in leptin, on altering adiponectin expression in humans. Methods/Results Forty four normal-weight healthy subjects were recruited (mean age 29 years; 14 women) and randomized to either gain 5% of body weight by 8-weeks of overfeeding (n=34) or maintain weight (n=10). Modest weight gain of 3.8 ± 1.2 kg resulted in increased adiponectin (p=0.03) while weight maintenance resulted in no changes in adiponectin. Further, changes in adiponectin correlated positively with changes in leptin (p=0.0085). In-vitro experiments using differentiated human white preadipocytes showed that leptin increased adiponectin mRNA and protein expression, while a leptin-antagonist had opposite effects. To understand the role of leptin in established obesity, we compared adipose tissue samples obtained from normal weight versus obese subjects. We noted, first, that leptin activated cellular signaling pathways and increased adiponectin mRNA in adipose tissue from normal-weight participants, but did not do so in adipose tissue from obese participants; and second, that obese subjects had increased caveolin-1 expression, which attenuates leptin-dependent increases in adiponectin. Conclusions Modest weight gain in healthy individuals is associated with increases in adiponectin, which correlate positively with changes in leptin. In-vitro, leptin induces adiponectin expression which is attenuated by increased caveolin-1 expression. Additionally, adipose tissue from obese subjects shows increased caveolin-1 expression, and impaired leptin signaling. This leptin signal impairment may prevent concordant increases in adiponectin in obese subjects despite their high levels of leptin. Therefore, impaired leptin signaling may contribute to low adiponectin expression in obesity and may provide a target for increasing adiponectin expression, hence improving insulin sensitivity and cardio-metabolic profile in obesity.
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Zhao ZJ, Liu YA, Xing JY, Zhang ML, Ni XY, Cao J. The role of leptin in striped hamsters subjected to food restriction and refeeding. DONG WU XUE YAN JIU = ZOOLOGICAL RESEARCH 2014; 35:262-71. [PMID: 25017744 DOI: 10.13918/j.issn.2095-8137.2014.4.262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Food restriction (FR) and refeeding (Re) have been suggested to impair body mass regulation and thereby making it easier to regain the lost weight and develop over-weight when FR ends. However, it is unclear if this is the case in small mammals showing seasonal forging behaviors. In the present study, energy budget, body fat and serum leptin level were measured in striped hamsters that were exposed to FR-Re. The effects of leptin on food intake, body fat and genes expressions of several hypothalamus neuropeptides were determined. Body mass, fat content and serum leptin level decreased during FR and then increased during Re. Leptin supplement significantly attenuated the increase in food intake during Re, decreased genes expressions of neuropepetide Y (NPY) and agouti-related protein (AgRP) of hypothalamus and leptin of white adipose tissue (WAT). Hormone-sensitive lipase (HSL) gene expression of WAT increased in leptin-treated hamsters that were fed ad libitum, but decreased in FR-Re hamsters. This indicates that the adaptive regulation of WAT HSL gene expression may be involved in the mobilization of fat storage during Re, which partly contributes to the resistance to FR-Re-induced overweight. Leptin may be involved in the down regulations of hypothalamus orexigenic peptides gene expression and consequently plays a crucial role in controlling food intake when FR ends.
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Affiliation(s)
- Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325027, China.
| | - Yong-An Liu
- School of Agricultural Science, Liaocheng University, Liaocheng 252059, China
| | - Jing-Ya Xing
- School of Agricultural Science, Liaocheng University, Liaocheng 252059, China
| | - Mao-Lun Zhang
- School of Agricultural Science, Liaocheng University, Liaocheng 252059, China
| | - Xiao-Ying Ni
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325027, China
| | - Jing Cao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325027, China;School of Agricultural Science, Liaocheng University, Liaocheng 252059, China
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Crépin D, Benomar Y, Riffault L, Amine H, Gertler A, Taouis M. The over-expression of miR-200a in the hypothalamus of ob/ob mice is linked to leptin and insulin signaling impairment. Mol Cell Endocrinol 2014; 384:1-11. [PMID: 24394757 DOI: 10.1016/j.mce.2013.12.016] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 12/25/2013] [Accepted: 12/27/2013] [Indexed: 01/08/2023]
Abstract
Early in life, leptin plays a crucial role in hypothalamic neural organization. Leptin, most likely, controls neural gene expression conferring then specific phenotype regarding energy homeostasis. MicroRNAs are new regulators for several physiological functions, including the regulation of metabolism. However, the impact of leptin on hypothalamic microRNA patterns remains unknown. Here, we demonstrate that miR-200a, miR-200b and miR-429 are up-regulated in the hypothalamus of genetically obese and leptin deficient ob/ob mice. Leptin treatment down-regulates these miRNAs in ob/ob hypothalamus. The hypothalamic silencing of miR-200a increased the expression level of leptin receptor and insulin receptor substrate 2, reduced body weight gain, and restored liver insulin responsiveness. In addition, the overexpression of pre-miR-200a in a human neuroblastoma cell line impaired insulin and leptin signaling. These findings link the alteration of leptin and insulin signaling to the up-regulation of hypothalamic miR-200a which could be a new target for treatment of obesity.
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Affiliation(s)
- Delphine Crépin
- CNRS, Center of Neurosciences Paris-Sud, UMR 8195, Orsay cedex F-91405, France; University Paris-Sud, UMR 8195, Orsay cedex F-91405, France
| | - Yacir Benomar
- CNRS, Center of Neurosciences Paris-Sud, UMR 8195, Orsay cedex F-91405, France; University Paris-Sud, UMR 8195, Orsay cedex F-91405, France
| | - Laure Riffault
- CNRS, Center of Neurosciences Paris-Sud, UMR 8195, Orsay cedex F-91405, France; University Paris-Sud, UMR 8195, Orsay cedex F-91405, France
| | - Hamza Amine
- CNRS, Center of Neurosciences Paris-Sud, UMR 8195, Orsay cedex F-91405, France; University Paris-Sud, UMR 8195, Orsay cedex F-91405, France
| | - Arieh Gertler
- The Institute of Biochemistry, Food Science, and Nutrition, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, PO Box 12, 76100 Rehovot, Israel
| | - Mohammed Taouis
- CNRS, Center of Neurosciences Paris-Sud, UMR 8195, Orsay cedex F-91405, France; University Paris-Sud, UMR 8195, Orsay cedex F-91405, France.
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Zhao ZJ, Chi QS, Cao J, Wang DH. Seasonal changes of body mass and energy budget in striped hamsters: the role of leptin. Physiol Biochem Zool 2014; 87:245-56. [PMID: 24642542 DOI: 10.1086/674974] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Proper adjustments of physiology and behavior are required for small mammals to cope with seasonal climate change. The aim of this study was to examine the role of leptin in the regulation of body mass and energy budget in striped hamsters. We first investigated seasonal changes in body mass, energy budget, and serum leptin levels in hamsters acclimated to outdoor natural daylight and ambient temperature. Then we assessed the effect of leptin administration on energy budget, serum lipoprotein lipase (LPL) and hepatic lipase (HL) activities, and gene expression of uncoupling protein 1 (UCP1) in brown adipose tissue and of hypothalamic neuropeptides associated with the regulation of energy balance in hamsters maintained at 21° and 5°C. Hamsters showed constant body mass throughout the four seasons but significantly increased food intake and thermogenesis in winter, compared to summer. Minimum body fat was observed in winter, and minimum serum leptin was found in autumn. Hamsters housed at 5°C showed higher energy intake, upregulated gene expression of UCP1 and hormone-sensitive lipase, and lower fat content and LPL and HL activity than the animals maintained at 21°C. Leptin administration had no effect on energy intake but increased maximal thermogenic capacity, as indicated by upregulated UCP1 gene expression at both 21° and 5°C. Body fat and activity of LPL and HL were decreased in hamsters treated with leptin. The results suggest that leptin plays an important role in the seasonal regulation of thermogenic capacity and body composition in striped hamsters. Leptin may be involved in increasing maximal thermogenesis in the cold rather than acting as a starvation signal to increase energy intake.
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Affiliation(s)
- Zhi-Jun Zhao
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325027, China; 2State Key Laboratory of Integrated Management for Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; 3School of Agricultural Science, Liaocheng University, Liaocheng, Shandong 252059, China
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Yonejima Y, Ushida K, Mori Y. Effect of Lactic Acid Bacteria on Lipid Metabolism and Fat Synthesis in Mice Fed a High-fat Diet. BIOSCIENCE OF MICROBIOTA FOOD AND HEALTH 2013; 32:51-8. [PMID: 24936362 PMCID: PMC4034319 DOI: 10.12938/bmfh.32.51] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 01/01/2013] [Indexed: 01/30/2023]
Abstract
Visceral fat accumulation is a major risk factor for the development of obesity-related
diseases, including diabetes, hyperlipidemia, hypertension, and arteriosclerosis.
Stimulation of lipolytic activity in adipose tissue or inhibition of fat synthesis is one
way to prevent these serious diseases. Lactic acid bacteria have an anti-obesity effect,
but the mechanisms are unclear. Therefore, we evaluated the effect of the administration
of lactic acid bacteria (Lactobacillus gasseri NT) on lipid metabolism
and fat synthesis in a mouse high-fat-diet model, focusing on visceral fat. Balb/c mice
were fed a 45 kcal% fat diet for 13 weeks with and without a freeze-dried preparation of
L. gasseri NT (109 CFU/g). An ex vivo
glycerol assay with periovarian fat revealed that L. gasseri NT did not
stimulate lipolytic activity. However, L. gasseri NT decreased the mRNA
expression of sterol regulatory element-binding protein (SREBP) and its target gene fatty
acid synthase (FAS) in the liver and decreased free fatty acid (FFA) in the blood. In
conclusion, these findings indicated that administration of L. gasseri NT
did not enhance lipid mobilization but can reduce fat synthesis, suggesting its potential
for improving obesity-related diseases.
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Affiliation(s)
- Yasunori Yonejima
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan ; Research and Development Department, Nitto Pharmaceutical Industries, Ltd., 35-3 Minamibiraki, Kamiueno-cho, Muko 617-0006, Japan
| | - Kazunari Ushida
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan
| | - Yoshiro Mori
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan
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Cedernaes J, Alsiö J, Västermark A, Risérus U, Schiöth HB. Adipose tissue stearoyl-CoA desaturase 1 index is increased and linoleic acid is decreased in obesity-prone rats fed a high-fat diet. Lipids Health Dis 2013; 12:2. [PMID: 23298201 PMCID: PMC3558438 DOI: 10.1186/1476-511x-12-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 01/05/2013] [Indexed: 01/19/2023] Open
Abstract
Background Fatty acid (FA) composition and desaturase indices are associated with obesity and related metabolic conditions. However, it is unclear to what extent desaturase activity in different lipid fractions contribute to obesity susceptibility. Our aim was to test whether desaturase activity and FA composition are linked to an obese phenotype in rats that are either obesity prone (OP) or resistant (OR) on a high-fat diet (HFD). Methods Two groups of Sprague–Dawley rats were given ad libitum (AL-HFD) or calorically restricted (HFD-paired; pair fed to calories consumed by chow-fed rats) access to a HFD. The AL-HFD group was categorized into OP and OR sub-groups based on weight gain over 5 weeks. Five different lipid fractions were examined in OP and OR rats with regard to proportions of essential and very long-chain polyunsaturated FAs: linoleic acid (LA), alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and the stearoyl-CoA desaturase 1 (SCD-1) product 16:1n-7. FA ratios were used to estimate activities of the delta-5-desaturase (20:4n-6/20:3n-6), delta-6-desaturase (18:3n-6/18:2n-6), stearoyl-CoA desaturase 1 (SCD-1; 16:1n-7/16:0, SCD-16 and 18:1n-9/18:0, SCD-18), de novo lipogenesis (16:0/18:2n-6) and FA elongation (18:0/16:0). Fasting insulin, glucose, adiponectin and leptin concentrations were measured in plasma. Results After AL-HFD access, OP rats had a significantly higher SCD-16 index and 16:1n-7 proportion, but a significantly lower LA proportion, in subcutaneous adipose tissue (SAT) triacylglycerols, as well as significantly higher insulin and leptin concentrations, compared with OR rats. No differences were found between the two phenotypes in liver (phospholipids; triacylglycerols) or plasma (cholesterol esters; phospholipids) lipid fractions or for plasma glucose or adiponectin concentrations. For the desaturase indices of the HFD-paired rats, the only significant differences compared with the OP or OR rats were higher SCD-16 and SCD-18 indices in SAT triacylglycerols in OP compared with HFD-paired rats. Conclusion The higher SCD-16 may reflect higher SCD-1 activity in SAT, which in combination with lower LA proportions may reflect higher insulin resistance and changes in SAT independent of other lipid fractions. Whether a lower SCD-16 index protects against diet-induced obesity is an interesting possibility that warrants further investigation.
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12
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Lu RH, Liang XF, Wang M, Zhou Y, Bai XL, He Y. The role of leptin in lipid metabolism in fatty degenerated hepatocytes of the grass carp Ctenopharyngodon idellus. FISH PHYSIOLOGY AND BIOCHEMISTRY 2012; 38:1759-1774. [PMID: 22760861 DOI: 10.1007/s10695-012-9673-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 06/01/2012] [Indexed: 06/01/2023]
Abstract
Leptin (Lep) is a key factor in the regulation of energy homeostasis in mammals, but its role in the fatty degenerated hepatocytes of the grass carp Ctenopharyngodon idellus is still unknown. The aim of our study is to determine the underlying mechanism and possible effects of C. idellus Lep function in lipid metabolism in C. idellus fatty degenerated hepatocytes. Fatty degenerated hepatocytes of C. idellus were established through treatment with media containing 0.1 % lipid emulsion (LE). Hepatic triglycerides had markedly accumulated in the treated hepatocytes 48 h later. Furthermore, we demonstrated that Lep dose dependently promoted the release of glycerol, but not FFA, in fatty degenerated hepatocytes. We also found that Lep affected the expression of key genes related to lipid metabolism at the transcriptional and translational levels. A total of ten genes, including HSL, ATGL, PPARα, PPARβ, UCP1, UCP2, PGC-1α, and CPTIα-1b, were markedly upregulated, while SCD1a and PPARγ were downregulated with Lep treatment. Moreover, the protein levels of HSL and ATGL and the LPL activity also significantly increased. The Lep-induced lipolysis was disrupted by the JAK-STAT inhibitor AG490, suggesting that JAK-STAT signaling pathways were involved in the process of Lep-induced lipolysis. Using the IRS-PI(3)K-specific inhibitor W1628, we found that only the Lep-induced downregulation of PPARγ was reduced. This result indicated that the IRS-PI(3)K signaling pathway was involved in the regulation of the adipogenic gene PPARγ. Overall, our results provided evidence that Lep directly stimulated JAK-STAT signaling-mediated lipolysis and fatty acid β-oxidation gene expression in the fatty degenerated hepatocytes of C. idellus and inhibited the adipogenesis mediated by the IRS-PI(3)K signaling pathway.
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Affiliation(s)
- Rong-Hua Lu
- College of Fisheries, Hua Zhong Agricultural University, Wuhan, 430070, China
| | - Xu-Fang Liang
- College of Fisheries, Hua Zhong Agricultural University, Wuhan, 430070, China.
| | - Min Wang
- College of Fisheries, Hua Zhong Agricultural University, Wuhan, 430070, China
| | - Yi Zhou
- College of Fisheries, Hua Zhong Agricultural University, Wuhan, 430070, China
| | - Xiao-Li Bai
- College of Fisheries, Hua Zhong Agricultural University, Wuhan, 430070, China
| | - Yan He
- College of Fisheries, Hua Zhong Agricultural University, Wuhan, 430070, China
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Adams AC, Yang C, Coskun T, Cheng CC, Gimeno RE, Luo Y, Kharitonenkov A. The breadth of FGF21's metabolic actions are governed by FGFR1 in adipose tissue. Mol Metab 2012; 2:31-7. [PMID: 24024127 DOI: 10.1016/j.molmet.2012.08.007] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 08/14/2012] [Accepted: 08/17/2012] [Indexed: 02/06/2023] Open
Abstract
FGF21 is a multifunctional metabolic regulator. The co-factor βKlotho (KLB) allows FGF21 to signal via FGF receptors. Given the widespread nature of FGFR expression and KLB presence in several organs, it remains unclear which tissue/FGFR isoform determine FGF21 action. Here we show that deletion of FGFR1 in fat (FR1KO) leads to a complete ablation of FGF21 stimulated transcriptional activity in this tissue. Furthermore, FR1KO mice showed no FGF21-mediated lowering of plasma glucose, insulin and triglycerides, altered serum levels of adipokines, no increase in energy expenditure, but preserved reductions in serum/liver FFAs as compared to wild type mice. Of importance, the anti-glycaemic actions of FGF19 were fully evident in FR1KO mice implying that FGF19 functions in a FGFR1/adipose independent manner. Taken together, our findings reveal the existence of an adipose FGFR1 driven axis of cross-tissue communication which defines several aspects of FGF21 biology and delineates mechanistic distinctions between FGF21 and FGF19.
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Key Words
- ACADL, Long chain acetyl-CoA dehydrogenase
- ACADVL, Very long chain acetyl-CoA dehydrogenase.
- Adipose tissue
- BAT, Brown adipose tissue
- DIO, Diet induced obese
- EGR1, Early growth response protein 1
- FFA, Free fatty acids
- FGF19
- FGF19, Fibroblast growth factor 19
- FGF21
- FGF21, Fibroblast growth factor 21
- FGFR, Fibroblast growth factor receptor
- FGFR1
- KLB, βKlotho
- PGC1α, PPARγ coactivator 1α
- SCD1, Stearoyl-Coenzyme A desaturase 1
- TG, Triglycerides
- UCP1, Uncoupling protein 1
- WAT, White adipose tissue
- βHB, β-HydroxyButyrate
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Affiliation(s)
- Andrew C Adams
- Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA
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Gómez Abellán P, Gómez Santos C, Madrid JA, Milagro FI, Campion J, Martínez JA, Luján JA, Ordovás JM, Garaulet M. Site-specific circadian expression of leptin and its receptor in human adipose tissue. NUTR HOSP 2012; 26:1394-401. [PMID: 22411388 DOI: 10.1590/s0212-16112011000600029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 06/02/2011] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Circadian variability of circulating leptin levels has been well established over the last decade. However, the circadian behavior of leptin in human adipose tissue remains unknown. This also applies to the soluble leptin receptor. OBJECTIVE We investigated the ex vivo circadian behavior of leptin and its receptor expression in human adipose tissue (AT). SUBJECTS AND METHODS Visceral and subcutaneous abdominal AT biopsies (n = 6) were obtained from morbid obese women (BMI ≥ 40 kg/m²). Anthropometric variables and fasting plasma glucose, leptin, lipids and lipoprotein concentrations were determined. In order to investigate rhythmic expression pattern of leptin and its receptor, AT explants were cultured during 24-h and gene expression was analyzed at the following times: 08:00, 14:00, 20:00, 02:00 h, using quantitative real-time PCR. RESULTS Leptin expression showed an oscillatory pattern that was consistent with circadian rhythm in cultured AT. Similar patterns were noted for the leptin receptor. Leptin showed its achrophase (maximum expression) during the night, which might be associated to a lower degree of fat accumulation and higher mobilization. When comparing both fat depots, visceral AT anticipated its expression towards afternoon and evening hours. Interestingly, leptin plasma values were associated with decreased amplitude of LEP rhythm. This association was lost when adjusting for waist circumference. CONCLUSION Circadian rhythmicity has been demonstrated in leptin and its receptor in human AT cultures in a site-specific manner. This new knowledge paves the way for a better understanding of the autocrine/paracrine role of leptin in human AT.
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Affiliation(s)
- P Gómez Abellán
- Department of Physiology, Faculty of Biology, University of Murcia, Murcia, Spain
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15
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Bartell SM, Rayalam S, Ambati S, Gaddam DR, Hartzell DL, Hamrick M, She JX, Della-Fera MA, Baile CA. Central (ICV) leptin injection increases bone formation, bone mineral density, muscle mass, serum IGF-1, and the expression of osteogenic genes in leptin-deficient ob/ob mice. J Bone Miner Res 2011; 26:1710-20. [PMID: 21520275 DOI: 10.1002/jbmr.406] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Both central and peripheral leptin administrations reduce body weight, food intake, and adiposity in ob/ob mice. In this study we compared effects of intracerebroventricular (ICV) and subcutaneous (SC) administration of leptin on bone metabolism in the appendicular and axial skeleton and adipose tissue gene expression and determined the effects of ICV leptin on bone marrow gene expression in ob/ob mice. In experiment 1, leptin (1.5 or 0.38 µg/d) or control was continuously injected ICV for 12 days. Gene expression analysis of femoral bone marrow stromal cells showed that expression of genes associated with osteogenesis was increased after ICV injection, whereas those associated with osteoclastogenesis, adipogenesis, and adipocyte lipid storage were decreased. In experiment 2, leptin was injected continuously ICV (0.0 or 1.5 µg/d) or SC (0.0 or 10 µg/d) for 12 days. In both experiments, regardless of mode of administration, leptin decreased body weight, food intake, and body fat and increased muscle mass, bone mineral density, bone mineral content, bone area, marrow adipocyte number, and mineral apposition rate. Serum insulin was decreased, whereas serum osteocalcin, insulin-like growth factor 1, osteoprotegerin, pyridinoline, and receptor activator of nuclear factor κB ligand concentrations were increased. In experiment 2, expression of genes in adipose tissue associated with apoptosis, lipid mobilization, insulin sensitivity, and thermogenesis was increased, whereas expression of genes associated with cell differentiation and maturation was decreased regardless of mode of administration. Thus ICV injection of leptin promotes expression of pro-osteogenic factors in bone marrow, leading to enhanced bone formation in ob/ob mice.
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Affiliation(s)
- Shoshana M Bartell
- Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602, USA
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16
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Ortega FJ, Jílková ZM, Moreno-Navarrete JM, Pavelka S, Rodriguez-Hermosa JI, Kopeck Ygrave J, Fernández-Real JM. Type I iodothyronine 5'-deiodinase mRNA and activity is increased in adipose tissue of obese subjects. Int J Obes (Lond) 2011; 36:320-4. [PMID: 21610697 DOI: 10.1038/ijo.2011.101] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Differentiation and metabolism of adipose tissue are modulated by thyroid hormones (THs), but relatively little is known about the metabolism of THs in this tissue. Expression of the genes for type I iodothyronine 5'-deiodinase (D1), leptin (LEP) and stearoyl-CoA desaturase 1 (SCD-1) was evaluated in omental (OM) and subcutaneous (SC) fat using a cohort of 70 humans. Activities of iodothyronine deiodinases (D1, D2 and D3) were assessed in a randomly selected subpopulation of 19 subjects. D1 expression was upregulated in both OM (P=0.011) and SC (P=0.003) fat of obese subjects. Concomitantly, OM (P=0.002) and SC (P=0.028) LEP expression were increased in obesity, associated with both D1 mRNA (r=0.315, P=0.014) and activity (r=0.647, P=0.023) and inversely related to SCD-1 (r=-0.266, P=0.034) expression in SC fat. Also D1 (but not D2 and D3) activity was increased in OM (∼fourfold, P=0.010) and SC (∼eightfold, P=0.004) fat of obese when compared with non-obese subjects and correlated in both OM (r=0.528, P=0.036) and SC (r=0.749, P=0.005) fat with body mass index. Our results document increased D1 gene expression and activity in adipose tissue of obese humans and suggest a role of 3,5,3'-triiodo-L-thyronine formed by D1 in response to leptin in the modulation of adipose tissue metabolism.
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Affiliation(s)
- F J Ortega
- Service of Diabetes, Endocrinology and Nutrition (UDEN), Institut d'Investigació Biomèdica de Girona, CIBER de Fisiopatología de Obesidad y Nutrición (CIBERobn, CB06/03/0010), and Instituto de Salud Carlos III, Girona, Spain
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Alhazzazi TY, Kamarajan P, Verdin E, Kapila YL. SIRT3 and cancer: tumor promoter or suppressor? Biochim Biophys Acta Rev Cancer 2011; 1816:80-8. [PMID: 21586315 DOI: 10.1016/j.bbcan.2011.04.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 04/28/2011] [Accepted: 04/29/2011] [Indexed: 12/18/2022]
Abstract
Sirtuins (SIRT1-7), the mammalian homologues of the Sir2 gene in yeast, have emerging roles in age-related diseases, such as cardiac hypertrophy, diabetes, obesity, and cancer. However, the role of several sirtuin family members, including SIRT1 and SIRT3, in cancer has been controversial. The aim of this review is to explore and discuss the seemingly dichotomous role of SIRT3 in cancer biology with particular emphasis on its potential role as a tumor promoter and tumor suppressor. This review will also discuss the potential role of SIRT3 as a novel therapeutic target to treat cancer.
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Affiliation(s)
- Turki Y Alhazzazi
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA
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18
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Mauvoisin D, Mounier C. Hormonal and nutritional regulation of SCD1 gene expression. Biochimie 2011; 93:78-86. [DOI: 10.1016/j.biochi.2010.08.001] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 07/16/2010] [Accepted: 08/03/2010] [Indexed: 01/08/2023]
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19
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Pro-apoptotic and anti-proliferative effects of mitofusin-2 via Bax signaling in hepatocellular carcinoma cells. Med Oncol 2010; 29:70-6. [PMID: 21190094 DOI: 10.1007/s12032-010-9779-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 12/08/2010] [Indexed: 01/12/2023]
Abstract
Mitochondrial GTPase mitofusin-2 (Mfn2) is a novel gene that remarkably suppresses the injury-mediated proliferation of vascular smooth muscle cells (VSMCs) and has a potential apoptotic effect via the mitochondrial apoptotic pathway. Hepatocellular carcinoma (HCC) tissues and matched normal tissues were examined for mfn2 expression. HCC cells were infected with adenovirus carrying Mfn2 (Ad-mfn2) or green fluorescent protein (Ad-GFP), used as a control. Short hairpin RNA (shRNA) was formed by shR-mfn2 and shR-Bax to repress mfn2 and Bax transcription, respectively. The effects of mfn2 on cell cycle distribution and apoptosis were measured by flow cytometric analysis. Significant downregulation of mfn2 was observed in HCC tissues compared with nearby normal tissues. Overexpression of mfn2 inhibited HCC cell proliferation and induced apoptosis by increasing the level of active caspase-3 and poly (ADP-ribose) polymerase (PARP) cleavage. Overexpression of mfn2 also induced cytochrome c release to the cytoplasm by enhancing Bax translocation from the cytoplasm to the mitochondrial membrane. Upregulation of mfn2 promoted apoptosis of HCC cells, and this was dramatically suppressed by shR-Bax. Our results show that the mfn2 gene is a potential tumor suppressor target that may significantly promote apoptosis via Bax and may inhibit proliferation in HCC cells. This gene may be an important therapeutic target for the treatment of tumors or hyperproliferative diseases.
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Adipokine update – neue Moleküle, neue Funktionen. Wien Med Wochenschr 2010; 160:377-90. [DOI: 10.1007/s10354-010-0781-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 01/12/2010] [Indexed: 12/15/2022]
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21
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Kim SK, Kong CS. Anti-adipogenic effect of dioxinodehydroeckol via AMPK activation in 3T3-L1 adipocytes. Chem Biol Interact 2010; 186:24-9. [PMID: 20385110 DOI: 10.1016/j.cbi.2010.04.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/30/2010] [Accepted: 04/02/2010] [Indexed: 11/16/2022]
Abstract
Dioxinodehydroeckol (DHE) isolated from Ecklonia cava, has previously been investigated for its inhibition of the differentiation of 3T3-L1 preadipocytes into adipocytes. Levels of lipid accumulation were measured, along with changes in the expression of genes and proteins associated with adipogenesis and lipolysis. Confluent 3T3-L1 preadipocytes in medium with or without different concentrations of DHE for 7 days were differentiated into adipocytes. Lipid accumulation was quantified by measuring direct triglyceride contents and Oil-Red O staining. The expression of genes and proteins associated with adipogenesis and lipolysis was measured using RT-PCR, quantitative real-time RT-PCR and Western blotting analysis. It was found that the presence of DHE significantly reduced lipid accumulation and down-regulated the expression of peroxisome proliferator-activated receptor-gamma (PPARgamma), sterol regulatory element-binding protein 1 (SREBP1) and CCAAT/enhancer-binding proteins (C/EBPalpha) in a dose-dependent manner. Moreover, DHE suppressed regulation of the adipocyte-specific gene promoters such as fatty acid binding protein (FABP4), fatty acid transport protein (FATP1), fatty acid synthase (FAS), lipoprotein lipase (LPL), acyl-CoA synthetase 1 (ACS1), leptin, perilipin and HSL compared to control adipocytes. The specific mechanism mediating the effects of DHE was confirmed by activation of phosphorylated AMP-activated protein kinase (pAMPK). Therefore, these results suggest that DHE exerts anti-adipogenic effect on adipocyte differentiation through the activation and modulation of the AMPK signaling pathway.
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Affiliation(s)
- Se-Kwon Kim
- Marine Bioprocess Research Center, Pukyong National University, Busan, Republic of Korea.
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22
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Kong CS, Kim JA, Ahn BN, Vo TS, Yoon NY, Kim SK. 1-(3',5'-dihydroxyphenoxy)-7-(2'',4'',6-trihydroxyphenoxy)-2,4,9-trihydroxydibenzo-1,4-dioxin inhibits adipocyte differentiation of 3T3-L1 fibroblasts. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2010; 12:299-307. [PMID: 19680725 DOI: 10.1007/s10126-009-9224-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 07/14/2009] [Indexed: 05/28/2023]
Abstract
In this study, we isolated the phloroglucinol derivative, 1-(3',5'-dihydroxyphenoxy)-7-(2'',4'',6-trihydroxyphenoxy)-2,4,9-trihydroxydibenzo-1,4-dioxin (1), from Ecklonia cava and evaluated its potential inhibition on adipocyte differentiation in 3T3-L1 cells. Lipid accumulation along with the expression of several genes associated with adipogenesis and lipolysis was examined at the end of differentiation. Lipid accumulation level was examined by measuring triglyceride content and Oil-Red O staining. The expression levels of several genes and proteins were examined using reverse-transcription polymerase chain reaction (RT-PCR), real-time RT-PCR, and Western blot analysis. Compound 1 significantly reduced lipid accumulation and downregulated peroxisome proliferator-activated receptor-gamma, sterol regulatory element-binding protein 1c, and CCAAT/enhancer-binding proteins alpha in a dose-dependent manner. Moreover, the presence of compound 1 induced downregulation of adipogenic target genes such as fatty acid binding protein 4, fatty acid transport protein 1, fatty acid synthase, acyl-CoA synthetase 1, lipoprotein lipase, and leptin. According to the lipolytic response, compound 1 downregulated perilipin and hormone-sensitive lipase while upregulating tumor necrosis factor alpha. Therefore, these results suggest that compound 1 might decrease lipid accumulation during adipocyte differentiation by modulating adipogenesis and lipogenesis. Furthermore, compound 1 could be developed as a functional agent effective in improving obesity.
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Affiliation(s)
- Chang-Suk Kong
- Marine Bioprocess Research Center, Pukyong National University, Busan, 608-737, South Korea
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Sánchez J, Cladera MM, Llopis M, Palou A, Picó C. The different satiating capacity of CHO and fats can be mediated by different effects on leptin and ghrelin systems. Behav Brain Res 2010; 213:183-8. [PMID: 20450938 DOI: 10.1016/j.bbr.2010.04.051] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 04/28/2010] [Accepted: 04/28/2010] [Indexed: 12/31/2022]
Abstract
Leptin and ghrelin are known to be the main hormones involved in the control of food intake, with opposite effects. Here we aimed to assess whether changes in leptin and ghrelin systems can be involved in the different satiating capacities of carbohydrates (CHO) and fat. Adult male Wistar rats were studied under 24h fasting conditions and after 24h fasting followed by a 12h re-feeding period with 64 kcal of CHO or fat, consisting of a mixture of wheat starch and sucrose or bacon, respectively. Serum levels of leptin and ghrelin, and mRNA levels of leptin and ObRb in the retroperitoneal and inguinal adipose tissue and of NPY, POMC, ObRb and GSHR in the hypothalamus were measured. CHO re-feeding resulted in higher leptin mRNA expression levels in the retroperitoneal adipose tissue and in higher circulating leptin levels compared with those after fat re-feeding. Moreover, circulating ghrelin levels and ghrelin/leptin ratio were significantly higher after fat re-feeding compared with CHO re-feeding, and hypothalamic expression levels of ghrelin receptor increased after fat, but not after CHO, re-feeding. Hence, expression levels of hypothalamic neuropeptides involved in food intake control and regulated by these hormones, particularly the orexigenic NPY and the anorexigenic pro-opiomelanocortin (POMC)-derived alpha-melanocyte-stimulating hormone, were also differently affected by CHO and fat re-feeding, resulting in a significantly lower NPY/POMC ratio after CHO re-feeding than after fat re-feeding. In conclusion, different effects on the leptin and ghrelin systems can account, at least in part, for the lower satiating capacity of fat compared to CHO.
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Affiliation(s)
- Juana Sánchez
- Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic Islands, Carretera Valldemossa Km 7.5, Palma de Mallorca, Spain
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SIRT3 regulates mitochondrial fatty-acid oxidation by reversible enzyme deacetylation. Nature 2010; 464:121-5. [PMID: 20203611 PMCID: PMC2841477 DOI: 10.1038/nature08778] [Citation(s) in RCA: 1240] [Impact Index Per Article: 88.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 12/21/2009] [Indexed: 01/01/2023]
Abstract
Sirtuins are NAD(+)-dependent protein deacetylases. They mediate adaptive responses to a variety of stresses, including calorie restriction and metabolic stress. Sirtuin 3 (SIRT3) is localized in the mitochondrial matrix, where it regulates the acetylation levels of metabolic enzymes, including acetyl coenzyme A synthetase 2 (refs 1, 2). Mice lacking both Sirt3 alleles appear phenotypically normal under basal conditions, but show marked hyperacetylation of several mitochondrial proteins. Here we report that SIRT3 expression is upregulated during fasting in liver and brown adipose tissues. During fasting, livers from mice lacking SIRT3 had higher levels of fatty-acid oxidation intermediate products and triglycerides, associated with decreased levels of fatty-acid oxidation, compared to livers from wild-type mice. Mass spectrometry of mitochondrial proteins shows that long-chain acyl coenzyme A dehydrogenase (LCAD) is hyperacetylated at lysine 42 in the absence of SIRT3. LCAD is deacetylated in wild-type mice under fasted conditions and by SIRT3 in vitro and in vivo; and hyperacetylation of LCAD reduces its enzymatic activity. Mice lacking SIRT3 exhibit hallmarks of fatty-acid oxidation disorders during fasting, including reduced ATP levels and intolerance to cold exposure. These findings identify acetylation as a novel regulatory mechanism for mitochondrial fatty-acid oxidation and demonstrate that SIRT3 modulates mitochondrial intermediary metabolism and fatty-acid use during fasting.
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Li GG, Liang XF, Xie Q, Li G, Yu Y, Lai K. Gene structure, recombinant expression and functional characterization of grass carp leptin. Gen Comp Endocrinol 2010; 166:117-27. [PMID: 19857495 DOI: 10.1016/j.ygcen.2009.10.009] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 10/11/2009] [Accepted: 10/20/2009] [Indexed: 10/20/2022]
Abstract
Leptin is an important hormone for the regulation of food intake, energy expenditure and reproduction in mammals, but information regarding its role in teleosts remains scant. In the present study, the gene structures of grass carp (Ctenopharyngodon idellus) and silver carp (Hypophthalmichthys molitrix) leptins were characterized. Recombinant grass carp leptin (rgc-LEP) was expressed in Escherichia coli and purified, and identified by mass spectrometric analysis. A strong anorexic effect on food intake was observed in grass carp on the first day after intraperitoneal (IP) injection of rgc-LEP, but not during the following days. Body weight of the leptin group (LEP group) and the pair-fed group (PF group) showed no difference throughout the experimental period. The acute and chronic effects on the expression of key genes correlating to food intake, energy expenditure, lipid metabolism and digestion were further characterized by real-time PCR. Accordingly, the mRNA levels of neuropeptide Y (NPY), Stearoyl-CoA desaturase 1 (SCD1) and lipoprotein lipase (LPL) were significantly reduced whereas the mRNA levels of uncoupling protein 2 (UCP2), bile salt-activated lipase (BSAL) and fatty acid elongase (ELO) were significantly elevated on the first day after injection. No effect on the expression of these genes (except LPL) was observed on day 13. In contrast to the down-regulation by exogenous leptin in mammals, the mRNA level of grass carp leptin was elevated 5.76-fold on the first day after rgc-LEP treatment. Our results suggest that leptin has an acute effect on the regulation of food intake, energy expenditure and lipid metabolism in grass carp, but the effect can be rapidly counteracted through mechanisms that are currently unknown.
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Affiliation(s)
- Guan-Gui Li
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China
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Yonezawa T, Kurata R, Hosomichi K, Kono A, Kimura M, Inoko H. Nutritional and hormonal regulation of uncoupling protein 2. IUBMB Life 2010; 61:1123-31. [PMID: 19946892 DOI: 10.1002/iub.264] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Uncoupling proteins (UCPs) belong to a family of mitochondrial carrier proteins that are present in the mitochondrial inner membrane. Genetic and experimental studies have shown that UCP dysfunction can be involved in metabolic disorders and in obesity. Uncoupling protein-1 (UCP1; also known as thermogenin) was identified in 1988 and found to be highly expressed in brown adipose tissue. UCP1 allows the leak of protons in respiring mitochondria, dissipating the energy as heat; the enzyme has an important role in nonshivering heat production induced by cold exposure or food intake. In 1997, two homologs of UCP1 were identified and named UCP2 and UCP3. These novel proteins also lower mitochondrial membrane potential, but whether they can dissipate metabolic energy as heat as efficiently as UCP1 is open to dispute. Even after a decade of study, the physiological roles of these novel proteins have still not been completely elucidated. This review aims to shed light on the nutritional and hormonal regulation of UCP2 and on its physiological roles.
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Affiliation(s)
- Tomo Yonezawa
- Division of Basic Molecular Science and Molecular Medicine, School of Medicine, Tokai University, Bohseidai, Ishehara, Kanagawa, Japan.
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Leptin intake during the suckling period improves the metabolic response of adipose tissue to a high-fat diet. Int J Obes (Lond) 2010; 34:809-19. [PMID: 20157325 DOI: 10.1038/ijo.2010.18] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND The intake of leptin during the suckling period protects against obesity and improves insulin and central leptin sensitivity in adult rats. OBJECTIVE We analyzed whether leptin treatment to neonates may also improve later peripheral leptin sensitivity in adipose tissue under high-fat (HF) diet conditions. DESIGN Male rats were supplemented with a daily oral dose of leptin or the vehicle (controls) during the suckling period. After weaning, animals were fed a normal-fat or an HF diet until the age of 6 months. At this age, mRNA and protein levels of the long-form leptin receptor (OB-Rb) and the expression of other genes related with energy metabolism were measured in various adipose depots (inguinal, mesenteric and retroperitoneal). RESULTS HF-diet feeding resulted in lower OB-Rb mRNA and protein levels in internal depots in controls but not in leptin-treated animals; these animals maintained OB-Rb mRNA and protein levels under HF-diet conditions in these depots, particularly in the mesenteric one, and this was accompanied by increased expression of genes related with energy uptake (GLUT4, CD36), fatty acid oxidation (peroxisome proliferator activated receptor-alpha (PPARalpha), CPT1, UCP3) and lipogenesis (PPARgamma, GPAT). Leptin-treatment also ameliorated HF-diet-induced hepatic fat accumulation occurring in control animals. CONCLUSION Leptin treatment during the suckling period may improve the lasting effects of HF-diet feeding on leptin receptor abundance in the adipose tissue and increase its oxidative capacity, resulting in a better handling and partitioning of excess fuel. This, together with the described improvement of central leptin sensitivity, may explain why these animals are more protected against diet-induced obesity and its metabolic-related disorders.
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Ambati S, Li Q, Rayalam S, Hartzell DL, Della-Fera MA, Hamrick MW, Baile CA. Central leptin versus ghrelin: effects on bone marrow adiposity and gene expression. Endocrine 2010; 37:115-23. [PMID: 19876773 DOI: 10.1007/s12020-009-9274-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
Abstract
This study compared the central effects of ghrelin and leptin on body and bone marrow adiposity and gene expression in adipose tissue and bone marrow. Male Sprague-Dawley rats were injected intracerebroventricular (ICV) twice daily with control, 66 ng ghrelin (G66), 330 ng ghrelin (G330), or 5 μg leptin (L5) for 5 days. Food intake (FI) and body weight (BW) were measured daily. Gene expression in adipose tissue and bone marrow was assessed using RT-PCR. Leptin reduced FI (P < 0.05) and BW (P < 0.05), whereas ghrelin increased BW (P < 0.05) without affecting FI. Leptin decreased fat pad weights, whereas ghrelin (G330) increased fat pad weights (P < 0.05). In epididymal adipose tissue, leptin increased expression of lipolysis marker ADRB2 and thermogenesis marker MFN2 and decreased expression of adipogenic markers, FASN, SLC2A4, and SCD1, whereas ghrelin increased expression of FASN and SCD1. Leptin decreased bone marrow adipocyte size and number; however, ghrelin had no effect on these parameters. In whole bone marrow, leptin decreased expression of FASN and SCD1 and increased expression of DLK1, whereas ghrelin (G330) decreased expression of COL1A1. Thus, leptin induces similar changes in bone marrow and adipose tissue gene expression, reflecting the decreased adiposity in both compartments.
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Affiliation(s)
- Suresh Ambati
- Department of Animal & Dairy Science, University of Georgia, 444 Animal Science Complex, Athens, GA 30602-2771, USA
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Ortega FJ, Mayas D, Moreno-Navarrete JM, Catalán V, Gómez-Ambrosi J, Esteve E, Rodriguez-Hermosa JI, Ruiz B, Ricart W, Peral B, Fruhbeck G, Tinahones FJ, Fernández-Real JM. The gene expression of the main lipogenic enzymes is downregulated in visceral adipose tissue of obese subjects. Obesity (Silver Spring) 2010; 18:13-20. [PMID: 19543203 DOI: 10.1038/oby.2009.202] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Contradictory findings regarding the gene expression of the main lipogenic enzymes in human adipose tissue depots have been reported. In this cross-sectional study, we aimed to evaluate the mRNA expression of fatty acid synthase (FAS) and acetyl-CoA carboxilase (ACC) in omental and subcutaneous (SC) fat depots from subjects who varied widely in terms of body fat mass. FAS and ACC gene expression were evaluated by real time-PCR in 188 samples of visceral adipose tissue which were obtained during elective surgical procedures in 119 women and 69 men. Decreased sex-adjusted FAS (-59%) and ACC (-49%) mRNA were found in visceral adipose tissue from obese subjects, with and without diabetes mellitus type 2 (DM-2), compared with lean subjects (both P < 0.0001). FAS mRNA was also decreased (-40%) in fat depots from overweight subjects (P < 0.05). Indeed, FAS mRNA was significantly and positively associated with ACC gene expression (r = 0.316, P < 0.0001) and negatively with BMI (r = -0.274), waist circumference (r = -0.437), systolic blood pressure (r = -0.310), serum glucose (r = -0.277), and fasting triglycerides (r = -0.226), among others (all P < 0.0001). Similar associations were observed for ACC gene expression levels. In a representative subgroup of nonobese (n = 4) and obese women (n = 6), relative FAS gene expression levels significantly correlated (r = 0.657, P = 0.034; n = 10) with FAS protein values. FAS protein levels were also inversely correlated with blood glucose (r = -0.640, P = 0.046) and fasting triglycerides (r = -0.832, P = 0.010). In conclusion, the gene expression of the main lipogenic enzymes is downregulated in visceral adipose tissue from obese subjects.
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Affiliation(s)
- Francisco J Ortega
- Service of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Girona, Spain
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30
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Pocai A, Carrington PE, Adams JR, Wright M, Eiermann G, Zhu L, Du X, Petrov A, Lassman ME, Jiang G, Liu F, Miller C, Tota LM, Zhou G, Zhang X, Sountis MM, Santoprete A, Capito' E, Chicchi GG, Thornberry N, Bianchi E, Pessi A, Marsh DJ, SinhaRoy R. Glucagon-like peptide 1/glucagon receptor dual agonism reverses obesity in mice. Diabetes 2009; 58:2258-66. [PMID: 19602537 PMCID: PMC2750209 DOI: 10.2337/db09-0278] [Citation(s) in RCA: 303] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Oxyntomodulin (OXM) is a glucagon-like peptide 1 (GLP-1) receptor (GLP1R)/glucagon receptor (GCGR) dual agonist peptide that reduces body weight in obese subjects through increased energy expenditure and decreased energy intake. The metabolic effects of OXM have been attributed primarily to GLP1R agonism. We examined whether a long acting GLP1R/GCGR dual agonist peptide exerts metabolic effects in diet-induced obese mice that are distinct from those obtained with a GLP1R-selective agonist. RESEARCH DESIGN AND METHODS We developed a protease-resistant dual GLP1R/GCGR agonist, DualAG, and a corresponding GLP1R-selective agonist, GLPAG, matched for GLP1R agonist potency and pharmacokinetics. The metabolic effects of these two peptides with respect to weight loss, caloric reduction, glucose control, and lipid lowering, were compared upon chronic dosing in diet-induced obese (DIO) mice. Acute studies in DIO mice revealed metabolic pathways that were modulated independent of weight loss. Studies in Glp1r(-/-) and Gcgr(-/-) mice enabled delineation of the contribution of GLP1R versus GCGR activation to the pharmacology of DualAG. RESULTS Peptide DualAG exhibits superior weight loss, lipid-lowering activity, and antihyperglycemic efficacy comparable to GLPAG. Improvements in plasma metabolic parameters including insulin, leptin, and adiponectin were more pronounced upon chronic treatment with DualAG than with GLPAG. Dual receptor agonism also increased fatty acid oxidation and reduced hepatic steatosis in DIO mice. The antiobesity effects of DualAG require activation of both GLP1R and GCGR. CONCLUSIONS Sustained GLP1R/GCGR dual agonism reverses obesity in DIO mice and is a novel therapeutic approach to the treatment of obesity.
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Affiliation(s)
| | | | | | | | | | - Lan Zhu
- Merck Research Laboratories, Rahway, NJ
| | | | | | | | | | | | | | | | | | | | | | - Alessia Santoprete
- Istituto di Ricerche di Biologia Molecolare P. Angeletti, Pomezia, Rome, Italy
| | - Elena Capito'
- Istituto di Ricerche di Biologia Molecolare P. Angeletti, Pomezia, Rome, Italy
| | | | | | - Elisabetta Bianchi
- Istituto di Ricerche di Biologia Molecolare P. Angeletti, Pomezia, Rome, Italy
| | - Antonello Pessi
- Istituto di Ricerche di Biologia Molecolare P. Angeletti, Pomezia, Rome, Italy
| | - Donald J. Marsh
- Merck Research Laboratories, Rahway, NJ
- Corresponding authors: Ranabir SinhaRoy, , and Donald J. Marsh,
| | - Ranabir SinhaRoy
- Merck Research Laboratories, Rahway, NJ
- Corresponding authors: Ranabir SinhaRoy, , and Donald J. Marsh,
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Jin L, Wei W, Jiang Y, Peng H, Cai J, Mao C, Dai H, Choy W, Bemis JE, Jirousek MR, Milne JC, Westphal CH, Perni RB. Crystal structures of human SIRT3 displaying substrate-induced conformational changes. J Biol Chem 2009; 284:24394-405. [PMID: 19535340 PMCID: PMC2782032 DOI: 10.1074/jbc.m109.014928] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 06/01/2009] [Indexed: 01/24/2023] Open
Abstract
SIRT3 is a major mitochondrial NAD(+)-dependent protein deacetylase playing important roles in regulating mitochondrial metabolism and energy production and has been linked to the beneficial effects of exercise and caloric restriction. SIRT3 is emerging as a potential therapeutic target to treat metabolic and neurological diseases. We report the first sets of crystal structures of human SIRT3, an apo-structure with no substrate, a structure with a peptide containing acetyl lysine of its natural substrate acetyl-CoA synthetase 2, a reaction intermediate structure trapped by a thioacetyl peptide, and a structure with the dethioacetylated peptide bound. These structures provide insights into the conformational changes induced by the two substrates required for the reaction, the acetylated substrate peptide and NAD(+). In addition, the binding study by isothermal titration calorimetry suggests that the acetylated peptide is the first substrate to bind to SIRT3, before NAD(+). These structures and biophysical studies provide key insight into the structural and functional relationship of the SIRT3 deacetylation activity.
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Affiliation(s)
- Lei Jin
- Sirtris, a GSK Company, Cambridge, Massachusetts 02139, USA.
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1,25-Dihydroxyvitamin D3 induces Ca2+-mediated apoptosis in adipocytes via activation of calpain and caspase-12. Biochem Biophys Res Commun 2009; 384:18-21. [DOI: 10.1016/j.bbrc.2009.04.078] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 04/04/2009] [Indexed: 12/11/2022]
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Kong CS, Kim JA, Eom TK, Kim SK. Phosphorylated glucosamine inhibits adipogenesis in 3T3-L1 adipocytes. J Nutr Biochem 2009; 21:438-43. [PMID: 19427183 DOI: 10.1016/j.jnutbio.2009.01.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 01/19/2009] [Accepted: 01/28/2009] [Indexed: 12/20/2022]
Abstract
Phosphorylated glucosamine (glucosamine-6-phosphate, PGlc) was synthesized using methanesulfonic acid, phosphorus pentoxide (P(2)O(5)), NH(2)NH(2) and DMF. Its inhibitory effect on lipid accumulation in cultured 3T3-L1 adipocytes was investigated by measuring triglyceride contents and Oil Red O staining. In order to understand the mechanism by which lipid accumulation in adipocytes is decreased by PGlc, we examined the expression levels of several genes and proteins associated with adipogenesis and lipolysis using reverse transcription polymerase chain reaction, real-time polymerase chain reaction and Western blot analysis. Treatment with PGlc significantly reduced lipid accumulation during adipocyte differentiation and induced down-regulation of peroxisome proliferator-activated receptor-gamma, sterol regulatory element binding protein 1 and CCAAT/enhancer binding protein-alpha in a dose-dependent manner. Moreover, treatment with PGlc during adipocyte differentiation induced significant up-regulation of preadipocyte factor 1 mRNA and down-regulation of such adipocyte-specific gene promoters as adipocyte fatty acid binding protein, fatty acid synthase, lipoprotein lipase and leptin. According to the lipolytic response, PGlc up-regulated hormone-sensitive lipase mRNA expression and suppressed the expression levels of tumor necrosis factor-alpha mRNA compared with fully differentiated adipose tissue. These results suggest that the inhibitory effect of PGlc on adipocyte differentiation might be mediated through the down-regulation of adipogenic transcription factors, such as peroxisome proliferator-activated receptor-gamma, sterol regulatory element binding protein 1 and CCAAT/enhancer binding protein-alpha, which are related to the downstream adipocyte-specific gene promoters.
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Affiliation(s)
- Chang-Suk Kong
- Marine Bioprocess Research Center, Pukyong National University, Busan, South Korea
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34
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Changes in lipid metabolism associated gene transcripts during porcine adipogenesis. Comp Biochem Physiol B Biochem Mol Biol 2009; 153:8-17. [DOI: 10.1016/j.cbpb.2008.12.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 12/23/2008] [Accepted: 12/31/2008] [Indexed: 11/20/2022]
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35
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Priego T, Sánchez J, Palou A, Picó C. Effect of high-fat diet feeding on leptin receptor expression in white adipose tissue in rats: depot- and sex-related differential response. GENES AND NUTRITION 2009; 4:151-6. [PMID: 19277751 DOI: 10.1007/s12263-009-0114-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 02/12/2009] [Indexed: 12/31/2022]
Abstract
Previous studies have illustrated the importance of leptin receptor (OB-Rb) mediated action on adipocytes in the regulation of body weight. The aim of the present study was to investigate in male and female rats the effects of high-fat (HF) diet feeding on the expression levels of OB-Rb in different depots of white adipose tissue (WAT), and its relation to fatty acid oxidation capacity. Male and female Wistar rats were fed until the age of 6 months with a normal-fat (NF) or non-isocaloric HF-diet (10 and 45% calories from fat, respectively). At this age, the weight of three different fat depots (retroperitoneal, mesenteric and inguinal) and the expression levels of OB-Rb, PPARalpha and CPT1 in these depots were measured. HF-diet feeding resulted in an increase in the weight of the different fat depots, the retroperitoneal depot being the one with the greatest increase in both sexes. In this depot, HF-diet feeding resulted in a significant decrease in OB-Rb mRNA levels, more marked in male than in female rats. In the mesenteric depot, the effects of HF-diet feeding on OB-Rb mRNA levels were sex-dependent: they decreased in males rats (associated with a decrease in PPARalpha and CPT1 mRNA levels), but increased in female rats. In the inguinal depot, OB-Rb expression was not affected by HF-diet feeding. These results show that a chronic intake of an HF-diet altered the expression of OB-Rb in WAT in a depot and sex-dependent manner. The decreased expression of OB-Rb in the internal depots of male rats under HF-diet feeding, with the resulting decrease in leptin sensitivity, can help to explain the higher tendency of males to suffer from obesity-linked disorders under HF-diet conditions.
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Affiliation(s)
- T Priego
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic Islands (UIB) and CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 07122, Palma de Mallorca, Spain
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Rabe K, Lehrke M, Parhofer KG, Broedl UC. Adipokines and insulin resistance. Mol Med 2008; 14:741-51. [PMID: 19009016 DOI: 10.2119/2008-00058.rabe] [Citation(s) in RCA: 512] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 09/08/2008] [Indexed: 12/27/2022] Open
Abstract
Obesity is associated with an array of health problems in adult and pediatric populations. Understanding the pathogenesis of obesity and its metabolic sequelae has advanced rapidly over the past decades. Adipose tissue represents an active endocrine organ that, in addition to regulating fat mass and nutrient homeostasis, releases a large number of bioactive mediators (adipokines) that signal to organs of metabolic importance including brain, liver, skeletal muscle, and the immune system--thereby modulating hemostasis, blood pressure, lipid and glucose metabolism, inflammation, and atherosclerosis. In the present review, we summarize current data on the effect of the adipose tissue-derived hormones adiponectin, chemerin, leptin, omentin, resistin, retinol binding protein 4, tumor necrosis factor-alpha and interleukin-6, vaspin, and visfatin on insulin resistance.
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Affiliation(s)
- Katja Rabe
- Department of Internal Medicine II, University of Munich, Munich, Germany
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