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Munkong N, Hansakul P, Yoysungnoen B, Wongnoppavich A, Sireeratawong S, Kaendee N, Lerdvuthisopon N. Vasoprotective effects of rice bran water extract on rats fed with high-fat diet. Asian Pac J Trop Biomed 2016. [DOI: 10.1016/j.apjtb.2016.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Farr OM, Tsoukas MA, Triantafyllou G, Dincer F, Filippaios A, Ko BJ, Mantzoros CS. Short-term administration of the GLP-1 analog liraglutide decreases circulating leptin and increases GIP levels and these changes are associated with alterations in CNS responses to food cues: A randomized, placebo-controlled, crossover study. Metabolism 2016; 65:945-53. [PMID: 27282865 PMCID: PMC4902873 DOI: 10.1016/j.metabol.2016.03.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/23/2016] [Accepted: 03/10/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND GLP-1 agonists, including liraglutide, have emerged as effective therapies for type 2 diabetes (DM) and obesity. Here, we attempted to delineate how liraglutide, at doses approved for DM, may impact circulating hormones influencing energy homeostasis in diabetics. BASIC PROCEDURES Using a randomized, placebo-controlled, double-blind, cross-over trial of 20 patients with type 2 diabetes, we examined the effects of liraglutide as compared to placebo on fasting levels of circulating hormones important to energy homeostasis, including leptin, ghrelin, PYY, and GIP. After 17days (0.6mg for 7days, 1.2mg for 7days and 1.8mg for 3days) of treatment, we also studied changes in fMRI responses to food cues. MAIN FINDINGS By design, to avoid any confounding by weight changes, subjects were studied for 17days, i.e. before body weight changed. Participants on liraglutide had significantly increased GLP-1 levels (p<0.001), decreased percent change in leptin levels (p<0.01) and increased GIP levels (p<0.03) in comparison to placebo treated subjects. Whole brain regressions of functional activity in response to food cues reveal that increased GIP levels were associated with deactivation of the attention- and reward-related insula. Decreases in leptin levels were associated with activations in the reward-related midbrain, precuneus, and dorsolateral prefrontal cortex (DLPFC), and sensorimotor-related motor cortex and with deactivations in the attention-related parietal cortex and the cognitive control-related thalamus and pre-SMA. PRINCIPAL CONCLUSIONS We demonstrate herein short-term changes to circulating levels of GIP and leptin in response to GLP-1 agonist liraglutide therapy. These findings suggest that liraglutide may alter the circulating levels of hormones important in energy homeostasis that, in turn, influence CNS perception of food cues. This could possibly lead to compensatory changes in energy homeostasis that could over time limit the efficacy of liraglutide to decrease body weight. These novel findings, which, pointing to the potential advantages of combination therapies, may have therapeutic implications, will need to be confirmed by larger and longer-term trials.
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Affiliation(s)
- Olivia M Farr
- Division of Endocrinology, Beth-Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215.
| | - Michael A Tsoukas
- Division of Endocrinology, Beth-Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215
| | - Georgios Triantafyllou
- Division of Endocrinology, Beth-Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215
| | - Fadime Dincer
- Division of Endocrinology, Beth-Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215
| | - Andreas Filippaios
- Division of Endocrinology, Beth-Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215
| | - Byung-Joon Ko
- Division of Endocrinology, Beth-Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215
| | - Christos S Mantzoros
- Division of Endocrinology, Beth-Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215
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De Sibio MT, Luvizotto RAM, Olimpio RMC, Corrêa CR, Marino J, de Oliveira M, Conde SJ, Ferreira ALDA, Padovani CR, Nogueira CR. A comparative genotoxicity study of a supraphysiological dose of triiodothyronine (T₃) in obese rats subjected to either calorie-restricted diet or hyperthyroidism. PLoS One 2013; 8:e56913. [PMID: 23468891 PMCID: PMC3585230 DOI: 10.1371/journal.pone.0056913] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 01/16/2013] [Indexed: 12/19/2022] Open
Abstract
This study was designed to determine the genotoxicity of a supraphysiological dose of triiodothyronine (T3) in both obese and calorie-restricted obese animals. Fifty male Wistar rats were randomly assigned to one of the two following groups: control (C; n = 10) and obese (OB; n = 40). The C group received standard food, whereas the OB group was fed a hypercaloric diet for 20 weeks. After this period, half of the OB animals (n = 20) were subjected to a 25%-calorie restriction of standard diet for 8 weeks forming thus a new group (OR), whereas the remaining OB animals were kept on the initial hypercaloric diet. During the following two weeks, 10 OR animals continued on the calorie restriction diet, whereas the remaining 10 rats of this group formed a new group (ORS) given a supraphysiological dose of T3 (25 µg/100 g body weight) along with the calorie restriction diet. Similarly, the remaining OB animals were divided into two groups, one that continued on the hypercaloric diet (OB, n = 10), and one that received the supraphysiological dose of T3 (25 µg/100 g body weight) along with the hypercaloric diet (OS, n = 10) for two weeks. The OB group showed weight gain, increased adiposity, insulin resistance, increased leptin levels and genotoxicity; T3 administration in OS animals led to an increase in genotoxicity and oxidative stress when compared with the OB group. The OR group showed weight loss and normalized levels of adiposity, insulin resistance, serum leptin and genotoxicity, thus having features similar to those of the C group. On the other hand, the ORS group, compared to OR animals, showed higher genotoxicity. Our results indicate that regardless of diet, a supraphysiological dose of T3 causes genotoxicity and potentiates oxidative stress.
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Affiliation(s)
- Maria Teresa De Sibio
- Department of Internal Medicine, Botucatu Medical School - University of Sao Paulo State (UNESP), Botucatu, SP, Brazil.
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Pasarín M, La Mura V, Gracia-Sancho J, García-Calderó H, Rodríguez-Vilarrupla A, García-Pagán JC, Bosch J, Abraldes JG. Sinusoidal endothelial dysfunction precedes inflammation and fibrosis in a model of NAFLD. PLoS One 2012. [PMID: 22509248 DOI: 10.1371/journal,pone.0032785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. Most morbidity associated with the metabolic syndrome is related to vascular complications, in which endothelial dysfunction is a major pathogenic factor. However, whether NAFLD is associated with endothelial dysfunction within the hepatic vasculature is unknown. The aims of this study were to explore, in a model of diet-induced overweight that expresses most features of the metabolic syndrome, whether early NAFLD is associated with liver endothelial dysfunction. Wistar Kyoto rats were fed a cafeteria diet (CafD; 65% of fat, mostly saturated) or a control diet (CD) for 1 month. CafD rats developed features of the metabolic syndrome (overweight, arterial hypertension, hypertryglyceridemia, hyperglucemia and insulin resistance) and liver steatosis without inflammation or fibrosis. CafD rats had a significantly higher in vivo hepatic vascular resistance than CD. In liver perfusion livers from CafD rats had an increased portal perfusion pressure and decreased endothelium-dependent vasodilation. This was associated with a decreased Akt-dependent eNOS phosphorylation and NOS activity. In summary, we demonstrate in a rat model of the metabolic syndrome that shows features of NAFLD, that liver endothelial dysfunction occurs before the development of fibrosis or inflammation.
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Affiliation(s)
- Marcos Pasarín
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
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Pasarín M, La Mura V, Gracia-Sancho J, García-Calderó H, Rodríguez-Vilarrupla A, García-Pagán JC, Bosch J, Abraldes JG. Sinusoidal endothelial dysfunction precedes inflammation and fibrosis in a model of NAFLD. PLoS One 2012; 7:e32785. [PMID: 22509248 PMCID: PMC3317918 DOI: 10.1371/journal.pone.0032785] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 02/03/2012] [Indexed: 12/14/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. Most morbidity associated with the metabolic syndrome is related to vascular complications, in which endothelial dysfunction is a major pathogenic factor. However, whether NAFLD is associated with endothelial dysfunction within the hepatic vasculature is unknown. The aims of this study were to explore, in a model of diet-induced overweight that expresses most features of the metabolic syndrome, whether early NAFLD is associated with liver endothelial dysfunction. Wistar Kyoto rats were fed a cafeteria diet (CafD; 65% of fat, mostly saturated) or a control diet (CD) for 1 month. CafD rats developed features of the metabolic syndrome (overweight, arterial hypertension, hypertryglyceridemia, hyperglucemia and insulin resistance) and liver steatosis without inflammation or fibrosis. CafD rats had a significantly higher in vivo hepatic vascular resistance than CD. In liver perfusion livers from CafD rats had an increased portal perfusion pressure and decreased endothelium-dependent vasodilation. This was associated with a decreased Akt-dependent eNOS phosphorylation and NOS activity. In summary, we demonstrate in a rat model of the metabolic syndrome that shows features of NAFLD, that liver endothelial dysfunction occurs before the development of fibrosis or inflammation.
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Affiliation(s)
- Marcos Pasarín
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
| | - Vincenzo La Mura
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
| | - Jorge Gracia-Sancho
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
| | - Héctor García-Calderó
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
| | - Aina Rodríguez-Vilarrupla
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
| | - Juan Carlos García-Pagán
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
| | - Jaime Bosch
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
| | - Juan G. Abraldes
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS, CIBERrehd, University of Barcelona, Barcelona, Spain
- * E-mail:
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Ma X, Hui H, Liu Z, He G, Hu J, Meng J, Guan L, Luo X. Poly-GLP-1, a novel long-lasting glucagon-like peptide-1 polymer, ameliorates hyperglycaemia by improving insulin sensitivity and increasing pancreatic beta-cell proliferation. Diabetes Obes Metab 2009; 11:953-65. [PMID: 19531053 DOI: 10.1111/j.1463-1326.2009.01070.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM The clinical value of glucagon-like peptide-1 (GLP-1) is restricted because of its short half-life. To overcome this limitation, a new polymer of GLP-1 was developed by prodrug strategy, termed Poly-GLP-1, and its pharmacological properties were investigated. METHODS The in vitro release kinetics of GLP-1 from Poly-GLP-1 was analysed by Western blot. Plasma GLP-1 levels following a single administration of Poly-GLP-1 were determined by enzyme-linked immunosorbent assay. The in vitro effects of Poly-GLP-1 were evaluated using isolated pancreatic islets. The acute effects on glycaemic control and food intake were investigated in C57BL/6J mice s.c. administered with Poly-GLP-1. The chronic effects of Poly-GLP-1 on glycaemic control were further assessed in C57BL/6J and db/db mice treated twice daily for 6 weeks. RESULTS Pro-GLP-1 dose dependently increased insulin secretion and decreased glucose, but did not exhibit the insulinotropic action in isolated pancreatic islets without plasma. The glucose-lowering actions of Poly-GLP-1 (3 nmol/kg) remained no less than 12 h after a single injection. Poly-GLP-1 caused a durable restoration of glycaemic control, food intake and body weight gain in db/db mice following 6-week administration. The chronic treatment with Poly-GLP-1 improved glucose tolerance and insulin sensitivity and increased beta-cell mass and proliferation in db/db mice. There was little effect on normal mice treated in the same manner. CONCLUSIONS Our results indicated that Poly-GLP-1, a novel GLP-1 polymer, has long-lasting and potent effects on glycaemic control in vivo, and these beneficial effects may be because of improvement of insulin sensitivity and promotion of islet growth and function.
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Affiliation(s)
- X Ma
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China
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Schaalan M, El-Abhar HS, Barakat M, El-Denshary ES. Westernized-like-diet-fed rats: effect on glucose homeostasis, lipid profile, and adipocyte hormones and their modulation by rosiglitazone and glimepiride. J Diabetes Complications 2009; 23:199-208. [PMID: 18407527 DOI: 10.1016/j.jdiacomp.2008.02.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 01/20/2008] [Accepted: 02/09/2008] [Indexed: 01/11/2023]
Abstract
Wersternized diet, containing high fat diet intake combined with high consumption of softdrinks, is accused with the emerge of modern epidemic obesity and diabesity. Therefore, we aimed to study the effect of this diet combination on the homeostasis of glucose, lipids, and some adipohormones in rats and to simulate the metabolic perturbations induced by the unhealthy Westernized diet intake, leading to the development of type 2 diabetes. To achieve this, we divided male Wistar rats (80-120 g) into two main groups: the first was fed commercial normal fat diet and the second received an in-house-prepared high-fat diet (HFD), combined with fructose in drinking water for a period of 6 weeks, followed by a subdiabetogenic dose of streptozotocin (STZ) (35 mg/kg) to produce frank hyperglycemia. The effect of this diet alone or after 2 weeks of treatment with rosiglitazone or glimepiride on glucose homeostasis, lipid profile, and levels of resistin and leptin was studied. The HFD/fructose/STZ diet elevated fasting plasma glucose, fructosamine, insulin, and homeostasis model assessment (HOMA) index, as well as serum triglycerides (TGs), total cholesterol (TC), and low-density lipoprotein cholesterol, with a decrease in high-density lipoprotein cholesterol. Hepatic TG and TC levels, as well as serum activities of aspartate transaminase (AST), alanine transaminase (ALT), and lactate dehydrogenase (LDH), were increased, suggesting a diet-induced hepatic steatosis, beside the increased levels of serum resistin and leptin. Rosiglitazone corrected the altered parameters measured, except for liver TGs; similarly, glimepiride reinstated the inverted parameters but raised insulin level and, consequently, the HOMA index. These results show that this diet could be used to induce an effect that mimics human type 2 diabetes with its metabolic disturbances and is suitable for screening the antidiabetic agents used for management of this disease.
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Affiliation(s)
- Mona Schaalan
- Biochemistry Department, Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt.
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Gómez-Ramos A, Domínguez J, Zafra D, Corominola H, Gomis R, Guinovart JJ, Avila J. Sodium tungstate decreases the phosphorylation of tau through GSK3 inactivation. J Neurosci Res 2006; 83:264-73. [PMID: 16397900 DOI: 10.1002/jnr.20726] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Tungstate treatment increases the phosphorylation of glycogen synthase kinase-3beta (GSK3beta) at serine 9, which triggers its inactivation both in cultured neural cells and in vivo. GSK3 phosphorylation is dependent on the activation of extracellular signal-regulated kinases 1/2 (ERK1/2) induced by tungstate. As a consequence of GSK3 inactivation, the phosphorylation of several GSK3-dependent sites of the microtubule-associated protein tau decreases. Tungstate reduces tau phosphorylation only in primed sequences, namely, those prephosphorylated by other kinases before GSK3beta modification, which are serines 198, 199, or 202 and threonine 231. The phosphorylation at these sites is involved in reduction of the interaction of tau with microtubules that occurs in Alzheimer's disease.
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Affiliation(s)
- Alberto Gómez-Ramos
- Centro de Biología Molecular, CSIC/UAM, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
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