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Borges JCO, Oliveira VAB, Serdan TDA, Silva FLR, Santos CS, Pauferro JRB, Ribas ASF, Manoel R, Pereira ACG, Correa IS, Pereira JNB, Bazotte RB, Levada-Pires AC, Pithon-Curi TC, Gorjão R, Curi R, Hirabara SM, Masi LN. Brain glucose hypometabolism and hippocampal inflammation in Goto-Kakizaki rats. Braz J Med Biol Res 2023; 56:e12742. [PMID: 37377307 DOI: 10.1590/1414-431x2023e12742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 05/05/2023] [Indexed: 06/29/2023] Open
Abstract
Brain glucose hypometabolism and neuroinflammation are early pathogenic manifestations in neurological disorders. Neuroinflammation may also disrupt leptin signaling, an adipokine that centrally regulates appetite and energy balance by acting on the hypothalamus and exerting neuroprotection in the hippocampus. The Goto-Kakizaki (GK) rat is a non-obese type 2 diabetes mellitus (T2DM) animal model used to investigate diabetes-associated molecular mechanisms without obesity jeopardizing effects. Wistar and GK rats received the maintenance adult rodent diet. Also, an additional control group of Wistar rats received a high-fat and high-sugar diet (HFHS) provided by free consumption of condensed milk. All diets and water were provided ad libitum for eight weeks. Brain glucose uptake was evaluated by 2-deoxy-2-[fluorine-18] fluoro-D-glucose under basal (saline administration) or stimulated (CL316,243, a selective β3-AR agonist) conditions. The animals were fasted for 10-12 h, anesthetized, and euthanized. The brain was quickly dissected, and the hippocampal area was sectioned and stored at -80°C in different tubes for protein and RNA analyses on the same animal. GK rats exhibited attenuated brain glucose uptake compared to Wistar animals and the HFHS group under basal conditions. Also, the hippocampus of GK rats displayed upregulated leptin receptor, IL-1β, and IL-6 gene expression and IL-1β and the subunit of the transcription factor NF-κB (p-p65) protein expression. No significant alterations were detected in the hippocampus of HFHS rats. Our data indicated that a genetic predisposition to T2DM has significant brain deteriorating features, including brain glucose hypometabolism, neuroinflammation, and leptin signaling disruption in the hippocampal area.
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Affiliation(s)
- J C O Borges
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - V A B Oliveira
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - T D A Serdan
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - F L R Silva
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - C S Santos
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - J R B Pauferro
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - A S F Ribas
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - R Manoel
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - A C G Pereira
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - I S Correa
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - J N B Pereira
- Seção de Produção de Imunobiológicos, Bioindustrial Centro, Instituto Butantan, São Paulo, SP, Brasil
| | - R B Bazotte
- Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Farmacologia e Terapêutica, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - A C Levada-Pires
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - T C Pithon-Curi
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - R Gorjão
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - R Curi
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
- Seção de Produção de Imunobiológicos, Bioindustrial Centro, Instituto Butantan, São Paulo, SP, Brasil
| | - S M Hirabara
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - L N Masi
- Programa Interdisciplinar de Ciências da Saúde, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
- Departamento de Ciências Fisiológicas, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brasil
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Prada PO, Hirabara SM, de Souza CT, Schenka AA, Zecchin HG, Vassallo J, Velloso LA, Carneiro E, Carvalheira JBC, Curi R, Saad MJ. Retraction Note to: L-glutamine supplementation induces insulin resistance in adipose tissue and improves insulin signalling in liver and muscle of rats with diet-induced obesity. Diabetologia 2018; 61:253. [PMID: 29119243 DOI: 10.1007/s00125-017-4477-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In light of forensic evidence indicating duplication and/or manipulation of western blot images the Editor-in-Chief is retracting the article cited above.
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Affiliation(s)
- P O Prada
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - S M Hirabara
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas da Universidade de São Paulo, San Paulo, Brazil
| | - C T de Souza
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - A A Schenka
- Departamento de Patologia, Universidade Estadual de Campinas, Campinas, San Paulo, Brazil
| | - H G Zecchin
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - J Vassallo
- Departamento de Patologia, Universidade Estadual de Campinas, Campinas, San Paulo, Brazil
| | - L A Velloso
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - E Carneiro
- Departamento de Fisiologia, Instituto Biomédico da Universidade Estadual de Campinas, Campinas, San Paulo, Brazil
| | - J B C Carvalheira
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - R Curi
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas da Universidade de São Paulo, San Paulo, Brazil
| | - M J Saad
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil.
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Silva EP, Borges LS, Mendes-da-Silva C, Hirabara SM, Lambertucci RH. l-Arginine supplementation improves rats' antioxidant system and exercise performance. Free Radic Res 2017; 51:281-293. [PMID: 28277983 DOI: 10.1080/10715762.2017.1301664] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Reactive species have great importance in sports performance, once they can directly regulate energy production, muscular contraction, inflammation, and fatigue. Therefore, the redox control is essential for athletes' performance. Studies demonstrated that l-arginine has an important role in the synthesis of urea, cell growth and production of nitric oxide, moreover, there are indications that it is also able to induce benefits to muscle antioxidant system through the upregulation of some antioxidant enzymes, and by inhibiting some pathways of reactive species production. Therefore, the aim of this study was to evaluate the effects of l-arginine supplementation on performance and oxidative stress of male rats (trained or not), submitted to a single session of high intensity exercise. Forty male Wistar rats were divided into four groups, control (C), control+l-arginine (C + A), trained (T), and trained+l-arginine (T + A). The aerobic training was conducted for 8 weeks. Data of maximum speed and time from tests were used as indicators of performance. Variables related to oxidative stress and antioxidant system were also evaluated. Aerobic training was capable to induce enhancements on animals' exercise performance and on their redox state. Additionally, supplementation improved rats' physical performance on both groups, control and trained. Different improvements between groups on the antioxidant capacity were observed. Nevertheless, considering the ergogenic effect of l-arginine and the lack of all positive adaptations promoted by the exercise training, untrained animals may be more exposed to oxidative damages after the practice of intense exercises.
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Affiliation(s)
- E P Silva
- a Institute of Physical Exercise Sciences and Sports, Cruzeiro do Sul University , Sao Paulo , Brazil
| | - L S Borges
- a Institute of Physical Exercise Sciences and Sports, Cruzeiro do Sul University , Sao Paulo , Brazil
| | - C Mendes-da-Silva
- b Laboratory of Neuroscience and Nutrition, Department of Biosciences , Federal University of Sao Paulo , Santos , Brazil
| | - S M Hirabara
- a Institute of Physical Exercise Sciences and Sports, Cruzeiro do Sul University , Sao Paulo , Brazil
| | - R H Lambertucci
- c Department of Biosciences , Federal University of Sao Paulo , Santos , Brazil
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Abreu P, Vitzel KF, Monteiro ICCR, Lima TI, Queiroz AN, Leal-Cardoso JH, Hirabara SM, Ceccatto VM. Effects of endurance training on reduction of plasma glucose during high intensity constant and incremental speed tests in Wistar rats. ACTA ACUST UNITED AC 2016; 49:e5226. [PMID: 27783805 PMCID: PMC5089229 DOI: 10.1590/1414-431x20165226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 09/06/2016] [Indexed: 12/03/2022]
Abstract
The aim of this research was to investigate the effects of endurance training on
reduction of plasma glucose during high intensity constant and incremental speed
tests in Wistar rats. We hypothesized that plasma glucose might be decreased in the
exercised group during heavy (more intense) exercise. Twenty-four 10-week-old male
Wistar rats were randomly assigned to sedentary and exercised groups. The
prescription of endurance exercise training intensity was determined as 60% of the
maximum intensity reached at the incremental speed test. The animals were trained by
running on a motorized treadmill, five days/week for a total period of 67 weeks.
Plasma glucose during the constant speed test in the exercised group at 20 m/min was
reduced at the 14th, 21st and 28th min compared to the sedentary group, as well at 25
m/min at the 21st and 28th min. Plasma glucose during the incremental speed test was
decreased in the exercised group at the moment of exhaustion (48th min) compared to
the sedentary group (27th min). Endurance training positively modulates the
mitochondrial activity and capacity of substrate oxidation in muscle and liver. Thus,
in contrast to other studies on high load of exercise, the effects of endurance
training on the decrease of plasma glucose during constant and incremental speed
tests was significantly higher in exercised than in sedentary rats and associated
with improved muscle and hepatic oxidative capacity, constituting an important
non-pharmacological intervention tool for the prevention of insulin resistance,
including type 2 diabetes mellitus.
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Affiliation(s)
- P Abreu
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
| | - K F Vitzel
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
| | - I C C R Monteiro
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
| | - T I Lima
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - A N Queiroz
- Hospital e Maternidade José Martiniano de Alencar, Fortaleza, CE, Brasil
| | - J H Leal-Cardoso
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - S M Hirabara
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil.,Instituto de Ciências da Atividade Física e Esporte, Universidade Cruzeiro do Sul, São Paulo, SP, Brasil
| | - V M Ceccatto
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
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da Silva EP, Nachbar RT, Levada-Pires AC, Hirabara SM, Lambertucci RH. Omega-3 fatty acids differentially modulate enzymatic anti-oxidant systems in skeletal muscle cells. Cell Stress Chaperones 2016; 21:87-95. [PMID: 26386577 PMCID: PMC4679743 DOI: 10.1007/s12192-015-0642-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/02/2015] [Accepted: 09/03/2015] [Indexed: 01/11/2023] Open
Abstract
During physical activity, increased reactive oxygen species production occurs, which can lead to cell damage and in a decline of individual's performance and health. The use of omega-3 polyunsaturated fatty acids as a supplement to protect the immune system has been increasing; however, their possible benefit to the anti-oxidant system is not well described. Thus, the aim of this study was to evaluate whether the omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) can be beneficial to the anti-oxidant system in cultured skeletal muscle cells. C2C12 myocytes were differentiated and treated with either eicosapentaenoic acid or docosahexaenoic acid for 24 h. Superoxide content was quantified using the dihydroethidine oxidation method and superoxide dismutase, catalase, and glutathione peroxidase activity, and expression was quantified. We observed that the docosahexaenoic fatty acids caused an increase in superoxide production. Eicosapentaenoic acid induced catalase activity, while docosahexaenoic acid suppressed superoxide dismutase activity. In addition, we found an increased protein expression of the total manganese superoxide dismutase and catalase enzymes when cells were treated with eicosapentaenoic acid. Taken together, these data indicate that the use of eicosapentaenoic acid may present both acute and chronic benefits; however, the treatment with DHA may not be beneficial to muscle cells.
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Affiliation(s)
- E P da Silva
- Institute of Physical Activity and Sport Sciences, Cruzeiro do Sul University, Galvao Bueno, 868, Sao Paulo, 01506-000, Sao Paulo, Brazil
| | | | - A C Levada-Pires
- Institute of Physical Activity and Sport Sciences, Cruzeiro do Sul University, Galvao Bueno, 868, Sao Paulo, 01506-000, Sao Paulo, Brazil
| | - S M Hirabara
- Institute of Physical Activity and Sport Sciences, Cruzeiro do Sul University, Galvao Bueno, 868, Sao Paulo, 01506-000, Sao Paulo, Brazil
- University of Sao Paulo, Sao Paulo, Brazil
| | - R H Lambertucci
- Institute of Physical Activity and Sport Sciences, Cruzeiro do Sul University, Galvao Bueno, 868, Sao Paulo, 01506-000, Sao Paulo, Brazil.
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Fiamoncini J, Turner N, Hirabara SM, Salgado TML, Marçal AC, Leslie S, da Silva SMA, Deschamps FC, Luz J, Cooney GJ, Curi R. Enhanced peroxisomal β-oxidation is associated with prevention of obesity and glucose intolerance by fish oil-enriched diets. Obesity (Silver Spring) 2013; 21:1200-7. [PMID: 23666909 DOI: 10.1002/oby.20132] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 10/07/2012] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The effects of different amounts of omega 3-polyunsaturated fatty acids in diets with normal or high content of fat on lipid and carbohydrate metabolism were investigated. DESIGN AND METHODS Mice were fed for 8 weeks on diets enriched with fish oil or lard at 10% or 60% of energy. Energy balance and energy expenditure were analyzed. Fatty acid (FA) oxidative capacity of the liver and the activity of enzymes involved in this pathway were assessed. RESULTS Fish oil-fed mice had lower body weight and adiposity compared with lard-fed animals, despite having lower rates of oxygen consumption. Mice fed diets containing fish oil also displayed lower glycemia, reduced fat content in the liver, and improved glucose tolerance compared with lard-fed animals. The fish oil-containing diets increased markers of hepatic peroxisomal content and increased the generation of metabolites derived from FA β-oxidation in liver homogenates. In contrast, no changes were observed in the content of mitochondrial electron transport chain proteins or carnitine palmitoyl transferase-1 in the liver, indicating little direct effect of fish oil on mitochondrial metabolism. CONCLUSION Collectively, our findings suggest that the energy inefficient oxidation of FAs in peroxisomes may be an important mechanism underlying the protection against obesity and glucose intolerance of fish oil administration.
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Affiliation(s)
- J Fiamoncini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
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Carvalho-Filho MA, Carvalho BM, Oliveira AG, Guadagnini D, Ueno M, Dias MM, Tsukumo DM, Hirabara SM, Reis LF, Curi R, Carvalheira JBC, Saad MJA. Double-stranded RNA-activated protein kinase is a key modulator of insulin sensitivity in physiological conditions and in obesity in mice. Endocrinology 2012; 153:5261-74. [PMID: 22948222 DOI: 10.1210/en.2012-1400] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The molecular integration of nutrient- and pathogen-sensing pathways has become of great interest in understanding the mechanisms of insulin resistance in obesity. The double-stranded RNA-dependent protein kinase (PKR) is one candidate molecule that may provide cross talk between inflammatory and metabolic signaling. The present study was performed to determine, first, the role of PKR in modulating insulin action and glucose metabolism in physiological situations, and second, the role of PKR in insulin resistance in obese mice. We used Pkr(-/-) and Pkr(+/+) mice to investigate the role of PKR in modulating insulin sensitivity, glucose metabolism, and insulin signaling in liver, muscle, and adipose tissue in response to a high-fat diet. Our data show that in lean Pkr(-/-) mice, there is an improvement in insulin sensitivity, and in glucose tolerance, and a reduction in fasting blood glucose, probably related to a decrease in protein phosphatase 2A activity and a parallel increase in insulin-induced thymoma viral oncogene-1 (Akt) phosphorylation. PKR is activated in tissues of obese mice and can induce insulin resistance by directly binding to and inducing insulin receptor substrate (IRS)-1 serine307 phosphorylation or indirectly through modulation of c-Jun N-terminal kinase and inhibitor of κB kinase β. Pkr(-/-) mice were protected from high-fat diet-induced insulin resistance and glucose intolerance and showed improved insulin signaling associated with a reduction in c-Jun N-terminal kinase and inhibitor of κB kinase β phosphorylation in insulin-sensitive tissues. PKR may have a role in insulin sensitivity under normal physiological conditions, probably by modulating protein phosphatase 2A activity and serine-threonine kinase phosphorylation, and certainly, this kinase may represent a central mechanism for the integration of pathogen response and innate immunity with insulin action and metabolic pathways that are critical in obesity.
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Affiliation(s)
- M A Carvalho-Filho
- Department of Internal Medicine, State University of Campinas, São Paulo, Brazil
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Abstract
AIM Glimepiride, a low-potency insulin secretagogue, is as efficient on glycaemic control as other sulphonylureas, suggesting an additional insulin-sensitizer role. The aim of the present study was to confirm the insulin-sensitizer role of glimepiride and to show extra-pancreatic effects of the drug. METHODS Three-month-old monosodium glutamate (MSG)-induced obese insulin-resistant rats were treated (OG) or not treated (O) with glimepiride for 4 weeks and compared with age-matched non-obese rats (C). Insulin sensitivity in whole body, glucose transporter 4 (GLUT4) protein content, glucose uptake and glycogen synthesis in oxidative skeletal muscle and phospho-glycogen synthase kinase (p-GSK3) and glycogen content in liver were analysed. RESULTS Insulin sensitivity, analysed by the insulin tolerance test, was 30% lower in O than in C rats (p < 0.05), and OG rats recovered this parameter (p < 0.05). In oxidative muscle, glimepiride increased the GLUT4 protein content (50%, p < 0.001) and recovered the obesity-induced reduction ( approximately 20%) of the in vitro insulin-stimulated glucose uptake and incorporation into glycogen. In liver, glimepiride increased p-GSK3 (p < 0.01) and glycogen (p < 0.05) contents. CONCLUSION The increased GLUT4 protein expression and glucose utilization in oxidative muscle and the increased insulin sensitivity and glycogen storage in liver evidence the insulin-sensitizer effect of glimepiride, which must be important to enable the glimepiride drug to promote an efficient glycaemic control.
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Prada PO, Hirabara SM, Souza CTD, Schenka AA, Zecchin HG, Vassallo J, Velloso LA, Carneiro E, Carvalheira JBC, Curi R, Saad MJ. L-glutamine supplementation induces insulin resistance in adipose tissue and improves insulin signalling in liver and muscle of rats with diet-induced obesity. Diabetologia 2007; 50:1949-1959. [PMID: 17604977 DOI: 10.1007/s00125-007-0723-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 04/30/2007] [Indexed: 01/22/2023]
Abstract
AIMS/HYPOTHESIS Diet-induced obesity (DIO) is associated with insulin resistance in liver and muscle, but not in adipose tissue. Mice with fat-specific disruption of the gene encoding the insulin receptor are protected against DIO and glucose intolerance. In cell culture, glutamine induces insulin resistance in adipocytes, but has no effect in muscle cells. We investigated whether supplementation of a high-fat diet with glutamine induces insulin resistance in adipose tissue in the rat, improving insulin sensitivity in the whole animal. MATERIALS AND METHODS Male Wistar rats received standard rodent chow or a high-fat diet (HF) or an HF supplemented with alanine or glutamine (HFGln) for 2 months. Light microscopy and morphometry, oxygen consumption, hyperinsulinaemic-euglycaemic clamp and immunoprecipitation/immunoblotting were performed. RESULTS HFGln rats showed reductions in adipose mass and adipocyte size, a decrease in the activity of the insulin-induced IRS-phosphatidylinositol 3-kinase (PI3-K)-protein kinase B-forkhead transcription factor box 01 pathway in adipose tissue, and an increase in adiponectin levels. These results were associated with increases in insulin-stimulated glucose uptake in skeletal muscle and insulin-induced suppression of hepatic glucose output, and were accompanied by an increase in the activity of the insulin-induced IRS-PI3-K-Akt pathway in these tissues. In parallel, there were decreases in TNFalpha and IL-6 levels and reductions in c-jun N-terminal kinase (JNK), IkappaB kinase subunit beta (IKKbeta) and mammalian target of rapamycin (mTOR) activity in the liver, muscle and adipose tissue. There was also an increase in oxygen consumption and a decrease in the respiratory exchange rate in HFGln rats. CONCLUSIONS/INTERPRETATION Glutamine supplementation induces insulin resistance in adipose tissue, and this is accompanied by an increase in the activity of the hexosamine pathway. It also reduces adipose mass, consequently attenuating insulin resistance and activation of JNK and IKKbeta, while improving insulin signalling in liver and muscle.
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Affiliation(s)
- P O Prada
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - S M Hirabara
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas da Universidade de São Paulo, San Paulo, Brazil
| | - C T de Souza
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - A A Schenka
- Departamento de Patologia, Universidade Estadual de Campinas, Campinas, San Paulo, Brazil
| | - H G Zecchin
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - J Vassallo
- Departamento de Patologia, Universidade Estadual de Campinas, Campinas, San Paulo, Brazil
| | - L A Velloso
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - E Carneiro
- Departamento de Fisiologia, Instituto Biomédico da Universidade Estadual de Campinas, Campinas, San Paulo, Brazil
| | - J B C Carvalheira
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil
| | - R Curi
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas da Universidade de São Paulo, San Paulo, Brazil
| | - M J Saad
- Departamento de Clínica Médica da Universidade Estadual de Campinas, Rua Tessália Viera de Camargo 126, Campinas, San Paulo, 13083-887, Brazil.
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Newsholme P, Haber EP, Hirabara SM, Rebelato ELO, Procopio J, Morgan D, Oliveira-Emilio HC, Carpinelli AR, Curi R. Diabetes associated cell stress and dysfunction: role of mitochondrial and non-mitochondrial ROS production and activity. J Physiol 2007; 583:9-24. [PMID: 17584843 PMCID: PMC2277225 DOI: 10.1113/jphysiol.2007.135871] [Citation(s) in RCA: 455] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
It is now widely accepted, given the current weight of experimental evidence, that reactive oxygen species (ROS) contribute to cell and tissue dysfunction and damage caused by glucolipotoxicity in diabetes. The source of ROS in the insulin secreting pancreatic beta-cells and in the cells which are targets for insulin action has been considered to be the mitochondrial electron transport chain. While this source is undoubtably important, we provide additional information and evidence for NADPH oxidase-dependent generation of ROS both in pancreatic beta-cells and in insulin sensitive cells. While mitochondrial ROS generation may be important for regulation of mitochondrial uncoupling protein (UCP) activity and thus disruption of cellular energy metabolism, the NADPH oxidase associated ROS may alter parameters of signal transduction, insulin secretion, insulin action and cell proliferation or cell death. Thus NADPH oxidase may be a useful target for intervention strategies based on reversing the negative impact of glucolipotoxicity in diabetes.
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Affiliation(s)
- P Newsholme
- School of Biomolecular and Biomedical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
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Abstract
Several studies have shown impairment of neutrophil function, a disorder that contributes to the high incidence of infections in diabetes. Since glucose and glutamine play a key role in neutrophil function, we investigated their metabolism in neutrophils obtained from the peritoneal cavity of streptozotocin-induced diabetic rats. The activities of hexokinase, glucose-6-phosphate dehydrogenase (G6PDH), phosphofructokinase (PFK), citrate synthase, phosphate-dependent glutaminase, NAD+-linked and NADP+-linked isocitrate dehydrogenase were assayed. Glucose, glutamine, lactate, glutamate and aspartate, and the decarboxylation of [U-14C], [1-14C] and [6-14C]glucose; [U-14C]palmitic acid; and [U-14C]glutamine were measured in 1-h incubated neutrophils. Phagocytosis capacity and hydrogen peroxide (H2O2) production were also determined. All measurements were carried out in neutrophils from control, diabetic and insulin-treated (2-4 IU/day) diabetic rats. Phagocytosis and phorbol myristate acetate (PMA)-stimulated H2O2 production were decreased in neutrophils from diabetic rats. The activities of G6PDH and glutaminase were decreased, whereas that of PFK was raised by the diabetic state. The activities of the remaining enzymes were not changed. Diabetes decreased the decarboxylation of [1-14C]glucose and [U-14C]glutamine; however, [6-14C]glucose and [U-14C]palmitic acid decarboxylation was increased. These observations indicate that changes in metabolism may play an important role in the impaired neutrophil function observed in diabetes. The treatment with insulin abolished the changes induced by the diabetic state even with no marked change in glycemia. Therefore, insulin may have a direct effect on neutrophil metabolism and function.
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Affiliation(s)
- T C Alba-Loureiro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, 05508-900 São Paulo SP, Brazil.
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Piffar PM, Fernandez R, Tchaikovski O, Hirabara SM, Folador A, Pinto GJ, Jakobi S, Gobbo-Bordon D, Rohn TV, Fabrício VEB, Moretto KD, Tosta E, Curi R, Fernandes LC. Naproxen, clenbuterol and insulin administration ameliorates cancer cachexia and reduce tumor growth in Walker 256 tumor-bearing rats. Cancer Lett 2003; 201:139-48. [PMID: 14607327 DOI: 10.1016/s0304-3835(03)00472-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cancer cachexia is characterized by anorexia and intense peripheral catabolism. We examine the potential benefits of combination of different anabolic agents such as insulin and clenbuterol associated to prostaglandin synthesis inhibitor (naproxen) on tumor growth, cachexia and renal function in Walker 256 tumor-bearing rats (WK). Groups were separated into WK, and WK with naproxen (WK N) or naproxen plus clenbuterol (WK NCb) or naproxen plus clenbuterol plus insulin (WK NCbI). Treatment begins at the 4th day after tumor inoculation, at the 14th day they were killed, glycemia, lacticidemia, glycogen content from liver, soleus and gastrocnemius muscles, tumor mass, body weight and kidney function were determined. Glycemia and glycogen content were reduced and lacticidemia increased in WK (p<0.05) as compared to control rats. The glycogen content recovered in all treated groups. Tumor weight was significantly reduced by the different treatments. At the 14th weight change (carcass-initial body weight) in the control increased by 38% and in the WK -2%. Naproxen treatment (WK N) induced an increased by 14%. The inclusion of clenbuterol (WK NCb) and insulin (WK NCbI) by 38 and 41%, respectively. Mean glomerular filtration rate (GFR) increased in the WK (p<0.05) as compared to control, but in the WK NCb the GFR was similar to control. Our results suggest that naproxen is able to reduce tumor growth and its association with insulin and clenbuterol induce mass weight gain and recovery energy fuel.
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Affiliation(s)
- P M Piffar
- Laboratório de Metabolismo Celular, Departamento de Fisiologia, Setor de Ciências Biológicas, Universidade Federal do Paraná, Centro Politécnico, Jd. das Américas, Curitiba-Pr 81530-990, Brazil
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