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Møller LLV, Nielsen IL, Knudsen JR, Andersen NR, Jensen TE, Sylow L, Richter EA. The p21-activated kinase 2 (PAK2), but not PAK1, regulates contraction-stimulated skeletal muscle glucose transport. Physiol Rep 2020; 8:e14460. [PMID: 32597567 PMCID: PMC7322983 DOI: 10.14814/phy2.14460] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 12/18/2022] Open
Abstract
AIM Muscle contraction stimulates skeletal muscle glucose transport. Since it occurs independently of insulin, it is an important alternative pathway to increase glucose transport in insulin-resistant states, but the intracellular signaling mechanisms are not fully understood. Muscle contraction activates group I p21-activated kinases (PAKs) in mouse and human skeletal muscle. PAK1 and PAK2 are downstream targets of Rac1, which is a key regulator of contraction-stimulated glucose transport. Thus, PAK1 and PAK2 could be downstream effectors of Rac1 in contraction-stimulated glucose transport. The current study aimed to test the hypothesis that PAK1 and/or PAK2 regulate contraction-induced glucose transport. METHODS Glucose transport was measured in isolated soleus and extensor digitorum longus (EDL) mouse skeletal muscle incubated either in the presence or absence of a pharmacological inhibitor (IPA-3) of group I PAKs or originating from whole-body PAK1 knockout, muscle-specific PAK2 knockout or double whole-body PAK1 and muscle-specific PAK2 knockout mice. RESULTS IPA-3 attenuated (-22%) the increase in glucose transport in response to electrically stimulated contractions in soleus and EDL muscle. PAK1 was dispensable for contraction-stimulated glucose transport in both soleus and EDL muscle. Lack of PAK2, either alone (-13%) or in combination with PAK1 (-14%), partly reduced contraction-stimulated glucose transport compared to control littermates in EDL, but not soleus muscle. CONCLUSION Contraction-stimulated glucose transport in isolated glycolytic mouse EDL muscle is partly dependent on PAK2, but not PAK1.
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Affiliation(s)
- Lisbeth L. V. Møller
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Ida L. Nielsen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Jonas R. Knudsen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Nicoline R. Andersen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Thomas E. Jensen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Lykke Sylow
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Erik A. Richter
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
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de Moura LP, Souza Pauli LS, Cintra DE, de Souza CT, da Silva ASR, Marinho R, de Melo MAR, Ropelle ER, Pauli JR. Acute exercise decreases PTP-1B protein level and improves insulin signaling in the liver of old rats. IMMUNITY & AGEING 2013; 10:8. [PMID: 23442260 PMCID: PMC3599175 DOI: 10.1186/1742-4933-10-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/20/2013] [Indexed: 11/17/2022]
Abstract
It is now commonly accepted that chronic inflammation associated with obesity during aging induces insulin resistance in the liver. In the present study, we investigated whether the improvement in insulin sensitivity and insulin signaling, mediated by acute exercise, could be associated with modulation of protein-tyrosine phosphatase 1B (PTP-1B) in the liver of old rats. Aging rats were subjected to swimming for two 1.5-h long bouts, separated by a 45 min rest period. Sixteen hours after the exercise, the rats were sacrificed and proteins from the insulin signaling pathway were analyzed by immunoblotting. Our results show that the fat mass was increased in old rats. The reduction in glucose disappearance rate (Kitt) observed in aged rats was restored 16 h after exercise. Aging increased the content of PTP-1B and attenuated insulin signaling in the liver of rats, a phenomenon that was reversed by exercise. Aging rats also increased the IRβ/PTP-1B and IRS-1/PTP-1B association in the liver when compared with young rats. Conversely, in the liver of exercised old rats, IRβ/PTP-1B and IRS-1/PTP-1B association was markedly decreased. Moreover, in the hepatic tissue of old rats, the insulin signalling was decreased and PEPCK and G6Pase levels were increased when compared with young rats. Interestingly, 16 h after acute exercise, the PEPCK and G6Pase protein level were decreased in the old exercised group. These results provide new insights into the mechanisms by which exercise restores insulin signalling in liver during aging.
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Affiliation(s)
- Leandro Pereira de Moura
- Universidade Estadual Paulista, UNESP, Curso de Pós-Graduação em Ciências da Motricidade Humana, Rio Claro, SP, Brazil
| | - Luciana Santos Souza Pauli
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | - Dennys Esper Cintra
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | | | | | - Rodolfo Marinho
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | - Maria Alice Rostom de Melo
- Universidade Estadual Paulista, UNESP, Curso de Pós-Graduação em Ciências da Motricidade Humana, Rio Claro, SP, Brazil
| | - Eduardo Rochete Ropelle
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | - José Rodrigo Pauli
- Universidade Estadual Paulista, UNESP, Curso de Pós-Graduação em Ciências da Motricidade Humana, Rio Claro, SP, Brazil.,Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil.,Curso de Ciências do Esporte, FCA-UNICAMP, Rua Pedro Zaccaria, 1300, Jardim Santa Luzia, Limeira, SP, Brazil
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Zhu M, Hu J, Perez E, Phillips D, Kim W, Ghaedian R, Napora JK, Zou S. Effects of long-term cranberry supplementation on endocrine pancreas in aging rats. J Gerontol A Biol Sci Med Sci 2011; 66:1139-51. [PMID: 21768504 DOI: 10.1093/gerona/glr105] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The effects of long-term cranberry consumption on age-related changes in endocrine pancreas are not fully understood. Here we treated male Fischer 344 rats with either 2% whole cranberry powder supplemented or normal rodent chow from 6 to 22 month old. Both groups displayed an age-related decline in basal plasma insulin concentrations, but this age-related decline was delayed by cranberry. Cranberry supplementation led to increased β-cell glucose responsiveness during the oral glucose tolerance test. Portal insulin concentration was 7.6-fold higher in rats fed cranberry, coupled with improved β-cell function. However, insulin resistance values were similar in both groups. Total β-cell mass and expression of pancreatic and duodenal homeobox 1 and insulin within islets were significantly enhanced in rats fed cranberry relative to controls. Furthermore, cranberry increased insulin release of an insulin-producing β-cell line, revealing its insulinotropic effect. These findings suggest that cranberry is of particular benefit to β-cell function in normal aging rats.
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Affiliation(s)
- Min Zhu
- Laboratory of Experimental Gerontology, NIH Biomedical Research Center, National Institute on Aging, Baltimore, MD 21224, USA
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Timmons BW, Bar-Or O, Riddell MC. Oxidation rate of exogenous carbohydrate during exercise is higher in boys than in men. J Appl Physiol (1985) 2003; 94:278-84. [PMID: 12391100 DOI: 10.1152/japplphysiol.00140.2002] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To determine whether the relative utilization of exogenous carbohydrate (CHO(exo)) differs between children and adults, substrate utilization during 60 min of cycling at 70% peak O(2) uptake was studied in 12 pre- and early pubertal boys (9.8 +/- 0.1 yr) and 10 men (22.1 +/- 0.5 yr) on two occasions. Subjects consumed either a placebo or a (13)C-enriched 6% CHO(exo) beverage (total volume per trial: 24 ml/kg). Substrate utilization was calculated for the final 30 min of exercise. During both trials, total fat oxidation was higher (5.4 +/- 0.5 vs. 3.0 +/- 0.4 mg x kg(-1) x min(-1), P < 0.001) and total CHO oxidation lower (27.4 +/- 1.5 vs. 34.8 +/- 1.2 mg x kg(-1) x min(-1), P < 0.001) in boys than in men, respectively. During the CHO(exo) trial, CHO(exo) oxidation was higher (P < 0.001) in boys (8.8 +/- 0.5 mg x kg(-1) x min(-1)) than in men (6.2 +/- 0.5 mg x kg(-1) x min(-1)) and provided a greater (P < 0.001) relative proportion of total energy in boys (21.8 +/- 1.4%) than in men (14.6 +/- 0.9%). These results suggest that, although endogenous CHO utilization during exercise is lower, the relative oxidation of ingested CHO is considerably higher in boys than in men. The greater reliance on CHO(exo) in boys may be important in preserving endogenous fuels and may be related to pubertal status.
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Affiliation(s)
- Brian W Timmons
- Children's Exercise and Nutrition Centre, McMaster University, Hamilton L8N 3Z5, Canada M3J 1P3
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Larkin LM, Reynolds TH, Supiano MA, Kahn BB, Halter JB. Effect of aging and obesity on insulin responsiveness and glut-4 glucose transporter content in skeletal muscle of Fischer 344 x Brown Norway rats. J Gerontol A Biol Sci Med Sci 2001; 56:B486-92. [PMID: 11682570 PMCID: PMC2714732 DOI: 10.1093/gerona/56.11.b486] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study investigated the metabolic changes with age in the Fischer 344 x Brown Norway rat and its suitability as an animal model of postmaturational insulin resistance. Specifically, we determined whether an age-associated decrease in glucose disposal is associated with diminished whole body insulin responsiveness and/or a decrease in glucose transporter (GLUT-4) protein and mRNA content in medial gastrocnemius muscle of male Fischer 344 x Brown Norway rats of ages 8, 18, and 28 months. Fasting plasma glucose was unchanged with age. There was a significant age effect on visceral adiposity, fasting plasma insulin levels, insulin responsiveness, and GLUT-4 protein content. Insulin responsiveness and GLUT-4 protein were lower in the 18-month-old rats than in the 8-month-old rats. The findings of age-associated increases in visceral adiposity and insulin resistance, and decreases in GLUT-4 in the Fisher 344 x Brown Norway rat, suggest that this rat strain may be an appropriate model for studying the effects of aging on glucose homeostasis.
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Affiliation(s)
- L M Larkin
- Division of Geriatric Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor 48109-0940, USA.
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Hatta H, Tonouchi M, Miskovic D, Wang Y, Heikkila JJ, Bonen A. Tissue-specific and isoform-specific changes in MCT1 and MCT4 in heart and soleus muscle during a 1-yr period. Am J Physiol Endocrinol Metab 2001; 281:E749-56. [PMID: 11551851 DOI: 10.1152/ajpendo.2001.281.4.e749] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the postnatal changes (days 10, 36, 84, 160, 365) of monocarboxylate transporters (MCT)1 and MCT4 in rat heart and soleus muscle. In the heart, MCT1 protein and mRNA remained unaltered from day 10 until 1 yr of age. Both MCT4 protein and mRNA in the heart were detected at 10 days of age, but the MCT4 protein and transcript were not detected thereafter. In the soleus muscle, MCT1 protein (+38%) and mRNA (+136%) increased during the first 84 days and remained stable until 1 yr of age. In contrast, soleus MCT4 protein decreased by 90% over the course of 1 yr, with the most rapid decrease (-60%) occurring by day 84 (P < 0.05). At the same time, MCT4 mRNA was increased by 74% from days 10 to 84 (P < 0.05), remaining stable thereafter. In conclusion, developmental changes in MCT transport proteins are tissue specific and isoform specific. Furthermore, it appears that MCT1 expression in the heart and MCT1 and MCT4 expression in the soleus are regulated by pretranslational processes, whereas posttranscriptional processes regulate MCT4 expression in the soleus muscle.
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Affiliation(s)
- H Hatta
- Department of Life Sciences (Sports Sciences), University of Tokyo, Tokyo 153, Japan
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