1
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Syngkli S, Singh SK, Rani RM, Das B. Genistein and metformin regulate glycerol kinase and the enzymes of glycerol 3-phosphate shuttle in a differential manner in myocytes, hepatocytes and adipocytes. Int J Biol Macromol 2024; 270:132296. [PMID: 38740159 DOI: 10.1016/j.ijbiomac.2024.132296] [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] [Received: 01/25/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024]
Abstract
Glycerol kinase (GK) and glycerol 3-phosphate dehydrogenase (GPDH) are critical in glucose homeostasis. The role of genistein and metformin on these enzymes and glucose production was investigated in C2C12, HepG2, and 3T3-L1 cells. Enzyme kinetics, Real-Time PCR and western blots were performed to determine enzyme activities and expressions of mRNAs and proteins. Glucose production and uptake were also measured in these cells. siRNAs were used to assess their impact on the enzymes and glucose production. Ki values for the compounds were determined using purified GK and GPDH. Genistein decreased GK activity by ∼45 %, while metformin reduced cGPDH and mGPDH activities by ∼32 % and ∼43 %, respectively. Insignificant changes in expressions (mRNAs and proteins) of the enzymes were observed. The compounds showed dose-dependent alterations in glucose production and uptake in these cells. Genistein non-competitively inhibited His-GK activity (Ki 19.12 μM), while metformin non-competitively inhibited His-cGPDH (Ki 75.52 μM) and mGPDH (Ki 54.70 μM) activities. siRNAs transfection showed ∼50 % and ∼35 % decrease in activities of GK and mGPDH and a decrease in glucose production (0.38-fold and 0.42-fold) in 3T3-L1 cells. Considering the differential effects of the compounds, this study may provide insights into the potential therapeutic strategies for type II diabetes mellitus.
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Affiliation(s)
- Superior Syngkli
- Biological Chemistry Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793022, India
| | - Sumit K Singh
- Biological Chemistry Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793022, India
| | - Riva M Rani
- Biological Chemistry Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793022, India
| | - Bidyadhar Das
- Biological Chemistry Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793022, India.
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2
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Sauzeau V, Beignet J, Vergoten G, Bailly C. Overexpressed or hyperactivated Rac1 as a target to treat hepatocellular carcinoma. Pharmacol Res 2022; 179:106220. [PMID: 35405309 DOI: 10.1016/j.phrs.2022.106220] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/31/2022] [Accepted: 04/05/2022] [Indexed: 12/12/2022]
Abstract
Despite novel targeted and immunotherapies, the prognosis remains bleak for patients with hepatocellular carcinoma (HCC), especially for advanced and/or metastatic forms. The rapid emergence of drug resistance is a major obstacle in the success of chemo-, targeted-, immuno-therapies of HCC. Novel targets are needed. The prominent roles of the small GTPase Rac1 in the development and progression of HCC are discussed here, together with its multiple protein partners, and the targeting of Rac1 with RNA-based regulators and small molecules. We discuss the oncogenic functions of Rac1 in HCC, including the contribution of Rac1 mutants and isoform Rac1b. Rac1 is a ubiquitous target, but the protein is frequently overexpressed and hyperactivated in HCC. It contributes to the aggressivity of the disease, with key roles in cancer cell proliferation, tumor metastasis and resistance to treatment. Small molecule targeting Rac1, indirectly or directly, have shown anticancer effects in HCC experimental models. Rac1-binding agents such as EHT 1864 and analogues offer novel opportunities to combat HCC. We discuss the different modalities to repress Rac1 overactivation in HCC with small molecules and the combination with reference drugs to promote cancer cell death and to repress cell invasion. We highlight the necessity to combine Rac1-targeted approach with appropriate biomarkers to select Rac1 activated tumors. Our analysis underlines the prominent oncogenic functions of Rac1 in HCC and discuss the modalities to target this small GTPase. Rac1 shall be considered as a valid target to limit the acquired and intrinsic resistance of HCC tumors and their metastatic potential.
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Affiliation(s)
- Vincent Sauzeau
- Université de Nantes, CHU Nantes, CNRS, INSERM, Institut du Thorax, Nantes, France.
| | - Julien Beignet
- SATT Ouest Valorisation, 30 boulevard Vincent Gâche, CS 70211, 44202 Nantes Cedex, France
| | - Gérard Vergoten
- University of Lille, Inserm, INFINITE - U1286, Institut de Chimie Pharmaceutique Albert Lespagnol (ICPAL), Faculté de Pharmacie, 3 rue du Professeur Laguesse, BP-83, 59006, Lille, France
| | - Christian Bailly
- OncoWitan, Scientific Consulting Office, Lille, Wasquehal 59290, France.
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3
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OUP accepted manuscript. Carcinogenesis 2022; 43:705-715. [DOI: 10.1093/carcin/bgac039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/08/2022] [Accepted: 04/29/2022] [Indexed: 11/12/2022] Open
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4
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Rodríguez-Fdez S, Bustelo XR. Rho GTPases in Skeletal Muscle Development and Homeostasis. Cells 2021; 10:cells10112984. [PMID: 34831205 PMCID: PMC8616218 DOI: 10.3390/cells10112984] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 02/07/2023] Open
Abstract
Rho guanosine triphosphate hydrolases (GTPases) are molecular switches that cycle between an inactive guanosine diphosphate (GDP)-bound and an active guanosine triphosphate (GTP)-bound state during signal transduction. As such, they regulate a wide range of both cellular and physiological processes. In this review, we will summarize recent work on the role of Rho GTPase-regulated pathways in skeletal muscle development, regeneration, tissue mass homeostatic balance, and metabolism. In addition, we will present current evidence that links the dysregulation of these GTPases with diseases caused by skeletal muscle dysfunction. Overall, this information underscores the critical role of a number of members of the Rho GTPase subfamily in muscle development and the overall metabolic balance of mammalian species.
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Affiliation(s)
- Sonia Rodríguez-Fdez
- Molecular Mechanisms of Cancer Program, Centro de Investigación del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain;
- Instituto de Biología Molecular y Celular del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), CSIC-University of Salamanca, 37007 Salamanca, Spain
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge CB2 0QQ, UK
- Correspondence: or
| | - Xosé R. Bustelo
- Molecular Mechanisms of Cancer Program, Centro de Investigación del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain;
- Instituto de Biología Molecular y Celular del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), CSIC-University of Salamanca, 37007 Salamanca, Spain
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5
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Machin PA, Tsonou E, Hornigold DC, Welch HCE. Rho Family GTPases and Rho GEFs in Glucose Homeostasis. Cells 2021; 10:cells10040915. [PMID: 33923452 PMCID: PMC8074089 DOI: 10.3390/cells10040915] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 12/17/2022] Open
Abstract
Dysregulation of glucose homeostasis leading to metabolic syndrome and type 2 diabetes is the cause of an increasing world health crisis. New intriguing roles have emerged for Rho family GTPases and their Rho guanine nucleotide exchange factor (GEF) activators in the regulation of glucose homeostasis. This review summates the current knowledge, focusing in particular on the roles of Rho GEFs in the processes of glucose-stimulated insulin secretion by pancreatic β cells and insulin-stimulated glucose uptake into skeletal muscle and adipose tissues. We discuss the ten Rho GEFs that are known so far to regulate glucose homeostasis, nine of which are in mammals, and one is in yeast. Among the mammalian Rho GEFs, P-Rex1, Vav2, Vav3, Tiam1, Kalirin and Plekhg4 were shown to mediate the insulin-stimulated translocation of the glucose transporter GLUT4 to the plasma membrane and/or insulin-stimulated glucose uptake in skeletal muscle or adipose tissue. The Rho GEFs P-Rex1, Vav2, Tiam1 and β-PIX were found to control the glucose-stimulated release of insulin by pancreatic β cells. In vivo studies demonstrated the involvement of the Rho GEFs P-Rex2, Vav2, Vav3 and PDZ-RhoGEF in glucose tolerance and/or insulin sensitivity, with deletion of these GEFs either contributing to the development of metabolic syndrome or protecting from it. This research is in its infancy. Considering that over 80 Rho GEFs exist, it is likely that future research will identify more roles for Rho GEFs in glucose homeostasis.
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Affiliation(s)
- Polly A. Machin
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
| | - Elpida Tsonou
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Cambridge CB22 3AT, UK;
| | - David C. Hornigold
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Cambridge CB22 3AT, UK;
| | - Heidi C. E. Welch
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
- Correspondence: ; Tel.: +44-(0)1223-496-596
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6
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Reichova A, Schaller F, Bukatova S, Bacova Z, Muscatelli F, Bakos J. The impact of oxytocin on neurite outgrowth and synaptic proteins in Magel2-deficient mice. Dev Neurobiol 2021; 81:366-388. [PMID: 33609001 DOI: 10.1002/dneu.22815] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/20/2021] [Accepted: 02/15/2021] [Indexed: 12/11/2022]
Abstract
Oxytocin contributes to the regulation of cytoskeletal and synaptic proteins and could, therefore, affect the mechanisms of neurodevelopmental disorders, including autism. Both the Prader-Willi syndrome and Schaaf-Yang syndrome exhibit autistic symptoms involving the MAGEL2 gene. Magel2-deficient mice show a deficit in social behavior that is rescued following the postnatal administration of oxytocin. Here, in Magel2-deficient mice, we showed that the neurite outgrowth of primary cultures of immature hippocampal neurons is reduced. Treatment with oxytocin reversed this abnormality. In the hippocampus of Magel2-deficient pups, we further demonstrated that several transcripts of neurite outgrowth-associated proteins, synaptic vesicle proteins, and cell-adhesion molecules are decreased. In the juvenile stage, when neurons are mature, normalization or even overexpression of most of these markers was observed, suggesting a delay in the neuronal maturation of Magel2-deficient pups. Moreover, we found reduced transcripts of the excitatory postsynaptic marker, Psd95 in the hippocampus and we observed a decrease of PSD95/VGLUT2 colocalization in the hippocampal CA1 and CA3 regions in Magel2-deficient mice, indicating a defect in glutamatergic synapses. Postnatal administration of oxytocin upregulated postsynaptic transcripts in pups; however, it did not restore the level of markers of glutamatergic synapses in Magel2-deficient mice. Overall, Magel2 deficiency leads to abnormal neurite outgrowth and reduced glutamatergic synapses during development, suggesting abnormal neuronal maturation. Oxytocin stimulates the expression of numerous genes involved in neurite outgrowth and synapse formation in early development stages. Postnatal oxytocin administration has a strong effect on development that should be considered for certain neuropsychiatric conditions in infancy.
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Affiliation(s)
- Alexandra Reichova
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Fabienne Schaller
- Mediterranean Institute of Neurobiology (INMED), Parc Scientifique de Luminy, Marseille, France
| | - Stanislava Bukatova
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Zuzana Bacova
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Françoise Muscatelli
- Mediterranean Institute of Neurobiology (INMED), Parc Scientifique de Luminy, Marseille, France
| | - Jan Bakos
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia.,Institute of Physiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
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7
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Yue Y, Zhang C, Zhao X, Liu S, Lv X, Zhang S, Yang J, Chen L, Duan H, Zhang Y, Yao Z, Niu W. Tiam1 mediates Rac1 activation and contraction-induced glucose uptake in skeletal muscle cells. FASEB J 2020; 35:e21210. [PMID: 33225507 DOI: 10.1096/fj.202001312r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/26/2020] [Accepted: 11/04/2020] [Indexed: 12/31/2022]
Abstract
Contraction-stimulated glucose uptake in skeletal muscle requires Rac1, but the molecular mechanism of its activation is not fully understood. Treadmill running was applied to induce C57BL/6 mouse hind limb skeletal muscle contraction in vivo and electrical pulse stimulation contracted C2C12 myotube cultures in vitro. The protein levels or activities of AMPK or the Rac1-specific GEF, Tiam1, were manipulated by activators, inhibitors, siRNA-mediated knockdown, and adenovirus-mediated expression. Activated Rac1 was detected by a pull-down assay and immunoblotting. Glucose uptake was measured using the 2-NBD-glucose fluorescent analog. Electrical pulse stimulated contraction or treadmill exercise upregulated the expression of Tiam1 in skeletal muscle in an AMPK-dependent manner. Axin1 siRNA-mediated knockdown diminished AMPK activation and upregulation of Tiam1 protein expression by contraction. Tiam1 siRNA-mediated knockdown diminished contraction-induced Rac1 activation, GLUT4 translocation, and glucose uptake. Contraction increased Tiam1 gene expression and serine phosphorylation of Tiam1 protein via AMPK. These findings suggest Tiam1 is part of an AMPK-Tiam1-Rac1 signaling pathway that mediates contraction-stimulated glucose uptake in skeletal muscle cells and tissue.
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Affiliation(s)
- Yingying Yue
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Chang Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Xiaoyun Zhao
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Sasa Liu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Xiaoting Lv
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China.,Clinical Laboratory, Cangzhou People's Hospital, Cangzhou, China
| | - Shitian Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Jianming Yang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Liming Chen
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Hongquan Duan
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Youyi Zhang
- Institute of Vascular Medicine, Peking University Third Hospital, Beijing, China
| | - Zhi Yao
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
| | - Wenyan Niu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China.,NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Pharmacy, General Hospital, Tianjin Medical University, Tianjin, China
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8
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Yue Y, Zhang C, Zhang X, Zhang S, Liu Q, Hu F, Lv X, Li H, Yang J, Wang X, Chen L, Yao Z, Duan H, Niu W. An AMPK/Axin1-Rac1 signaling pathway mediates contraction-regulated glucose uptake in skeletal muscle cells. Am J Physiol Endocrinol Metab 2020; 318:E330-E342. [PMID: 31846370 DOI: 10.1152/ajpendo.00272.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Contraction stimulates skeletal muscle glucose uptake predominantly through activation of AMP-activated protein kinase (AMPK) and Rac1. However, the molecular details of how contraction activates these signaling proteins are not clear. Recently, Axin1 has been shown to form a complex with AMPK and liver kinase B1 during glucose starvation-dependent activation of AMPK. Here, we demonstrate that electrical pulse-stimulated (EPS) contraction of C2C12 myotubes or treadmill exercise of C57BL/6 mice enhanced reciprocal coimmunoprecipitation of Axin1 and AMPK from myotube lysates or gastrocnemius muscle tissue. Interestingly, EPS or exercise upregulated total cellular Axin1 levels in an AMPK-dependent manner in C2C12 myotubes and gastrocnemius mouse muscle, respectively. Also, direct activation of AMPK with 5-aminoimidazole-4-carboxamide ribonucleotide treatment of C2C12 myotubes or gastrocnemius muscle elevated Axin1 protein levels. On the other hand, siRNA-mediated Axin1 knockdown lessened activation of AMPK in contracted myotubes. Further, AMPK inhibition with compound C or siRNA-mediated knockdown of AMPK or Axin1 blocked contraction-induced GTP loading of Rac1, p21-activated kinase phosphorylation, and contraction-stimulated glucose uptake. In summary, our results suggest that an AMPK/Axin1-Rac1 signaling pathway mediates contraction-stimulated skeletal muscle glucose uptake.
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Affiliation(s)
- Yingying Yue
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Chang Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
- School of Pharmacy, Research Center of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Xuejiao Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Shitian Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Qian Liu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Fang Hu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Xiaoting Lv
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Hanqi Li
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Jianming Yang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Xinli Wang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Liming Chen
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Zhi Yao
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Hongquan Duan
- School of Pharmacy, Research Center of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Wenyan Niu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
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9
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Wu J, Rowart P, Jouret F, Gassaway BM, Rajendran V, Rinehart J, Caplan MJ. Mechanisms involved in AMPK-mediated deposition of tight junction components to the plasma membrane. Am J Physiol Cell Physiol 2020; 318:C486-C501. [PMID: 31913699 DOI: 10.1152/ajpcell.00422.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
AMP-activated protein kinase (AMPK) activation promotes early stages of epithelial junction assembly. AMPK activation in MDCK renal epithelial cells facilitates localization of the junction-associated proteins aPKCζ and Par3 to the plasma membrane and promotes conversion of Cdc42, a key regulator of epithelial polarization and junction assembly, to its active GTP bound state. Furthermore, Par3 is an important regulator of AMPK-mediated aPKCζ localization. Both aPKCζ and Par3 serve as intermediates in AMPK-mediated junction assembly, with inhibition of aPKCζ activity or Par3 knockdown disrupting AMPK's ability to facilitate zonula occludens (ZO-1) localization. AMPK phosphorylates the adherens junction protein afadin and regulates its interaction with the tight-junction protein zonula occludens-1. Afadin is phosphorylated at two critical sites, S228 (residing within an aPKCζ consensus site) and S1102 (residing within an AMPK consensus site), that are differentially regulated during junction assembly and that exert different effects on the process. Expression of phospho-defective mutants (S228A and S1102A) perturbed ZO-1 localization to the plasma membrane during AMPK-induced junction assembly. Expression of S228A increased the ZO-1/afadin interaction, while S1102A reduced this interaction during extracellular calcium-induced junction assembly. Inhibition of aPKCζ activity also increased the ZO-1/afadin interaction. Taken together, these data suggest that aPKCζ phosphorylation of afadin terminates the ZO-1/afadin interaction and thus permits the later stages of junction assembly.
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Affiliation(s)
- Jingshing Wu
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
| | - Pascal Rowart
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - Francois Jouret
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - Brandon M Gassaway
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut.,Systems Biology Institute, Yale University, West Haven, Connecticut
| | - Vanathy Rajendran
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
| | - Jesse Rinehart
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut.,Systems Biology Institute, Yale University, West Haven, Connecticut
| | - Michael J Caplan
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
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Dreh, a long noncoding RNA repressed by metformin, regulates glucose transport in C2C12 skeletal muscle cells. Life Sci 2019; 236:116906. [PMID: 31614147 DOI: 10.1016/j.lfs.2019.116906] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/13/2019] [Accepted: 09/23/2019] [Indexed: 12/20/2022]
Abstract
AIMS The anti-hyperglycemic action of metformin on skeletal muscles is presently unclear. Long noncoding RNAs (lncRNAs) are implicated in multiple cellular functions. This study aims to explore the role of lncRNAs in the glucometabolic action of metformin on skeletal muscle cells. MAIN METHODS Metformin accumulation was assessed using [14C]-metformin. A lncRNA array was used to investigate metformin-regulated lncRNAs in C2C12 skeletal muscle cells. Knockdown studies were applied to evaluate the function of lncRNA Dreh. A colorimetric assay was used for the measurement of medium glucose concentration; glucose transport was assessed using [3H]-2-deoxyglucose; real-time PCR was used for RNA expression analysis, and western blotting was used to assess protein expression in myotubes. A Dreh overexpression plasmid was transfected into the cells. KEY FINDINGS Metformin accumulated in C2C12 myotubes. Metformin reduced medium glucose concentration and repressed lncRNA Dreh expression in the myotubes. Knockdown of Dreh in the myotubes resulted in reduced glucose concentration in the culture medium, increased glucose transport, and increased levels of GLUT4 protein in the plasma membrane. Overexpression of Dreh attenuated the glucose-lowering effect of metformin in myotubes. SIGNIFICANCE The glucoregulatory actions of metformin are mediated in part by a lncRNA, Dreh, in the skeletal muscle cells. Dreh is a novel regulator for glucose transport and could be a therapeutic target for diabetes.
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11
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Møller LLV, Klip A, Sylow L. Rho GTPases-Emerging Regulators of Glucose Homeostasis and Metabolic Health. Cells 2019; 8:E434. [PMID: 31075957 PMCID: PMC6562660 DOI: 10.3390/cells8050434] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/11/2022] Open
Abstract
Rho guanosine triphosphatases (GTPases) are key regulators in a number of cellular functions, including actin cytoskeleton remodeling and vesicle traffic. Traditionally, Rho GTPases are studied because of their function in cell migration and cancer, while their roles in metabolism are less documented. However, emerging evidence implicates Rho GTPases as regulators of processes of crucial importance for maintaining metabolic homeostasis. Thus, the time is now ripe for reviewing Rho GTPases in the context of metabolic health. Rho GTPase-mediated key processes include the release of insulin from pancreatic β cells, glucose uptake into skeletal muscle and adipose tissue, and muscle mass regulation. Through the current review, we cast light on the important roles of Rho GTPases in skeletal muscle, adipose tissue, and the pancreas and discuss the proposed mechanisms by which Rho GTPases act to regulate glucose metabolism in health and disease. We also describe challenges and goals for future research.
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Affiliation(s)
- Lisbeth Liliendal Valbjørn Møller
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100 Copenhagen Oe, Denmark.
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100 Copenhagen Oe, Denmark.
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12
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Comparative Transcriptome and Methylome Analysis in Human Skeletal Muscle Anabolism, Hypertrophy and Epigenetic Memory. Sci Rep 2019; 9:4251. [PMID: 30862794 PMCID: PMC6414679 DOI: 10.1038/s41598-019-40787-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 02/22/2019] [Indexed: 02/07/2023] Open
Abstract
Transcriptome wide changes in human skeletal muscle after acute (anabolic) and chronic resistance exercise (RE) induced hypertrophy have been extensively determined in the literature. We have also recently undertaken DNA methylome analysis (850,000 + CpG sites) in human skeletal muscle after acute and chronic RE, detraining and retraining, where we identified an association between DNA methylation and epigenetic memory of exercise induced skeletal muscle hypertrophy. However, it is currently unknown as to whether all the genes identified in the transcriptome studies to date are also epigenetically regulated at the DNA level after acute, chronic or repeated RE exposure. We therefore aimed to undertake large scale bioinformatical analysis by pooling the publicly available transcriptome data after acute (110 samples) and chronic RE (181 samples) and comparing these large data sets with our genome-wide DNA methylation analysis in human skeletal muscle after acute and chronic RE, detraining and retraining. Indeed, after acute RE we identified 866 up- and 936 down-regulated genes at the expression level, with 270 (out of the 866 up-regulated) identified as being hypomethylated, and 216 (out of 936 downregulated) as hypermethylated. After chronic RE we identified 2,018 up- and 430 down-regulated genes with 592 (out of 2,018 upregulated) identified as being hypomethylated and 98 (out of 430 genes downregulated) as hypermethylated. After KEGG pathway analysis, genes associated with ‘cancer’ pathways were significantly enriched in both bioinformatic analysis of the pooled transcriptome and methylome datasets after both acute and chronic RE. This resulted in 23 (out of 69) and 28 (out of 49) upregulated and hypomethylated and 12 (out of 37) and 2 (out of 4) downregulated and hypermethylated ‘cancer’ genes following acute and chronic RE respectively. Within skeletal muscle tissue, these ‘cancer’ genes predominant functions were associated with matrix/actin structure and remodelling, mechano-transduction (e.g. PTK2/Focal Adhesion Kinase and Phospholipase D- following chronic RE), TGF-beta signalling and protein synthesis (e.g. GSK3B after acute RE). Interestingly, 51 genes were also identified to be up/downregulated in both the acute and chronic RE pooled transcriptome analysis as well as significantly hypo/hypermethylated after acute RE, chronic RE, detraining and retraining. Five genes; FLNB, MYH9, SRGAP1, SRGN, ZMIZ1 demonstrated increased gene expression in the acute and chronic RE transcriptome and also demonstrated hypomethylation in these conditions. Importantly, these 5 genes demonstrated retained hypomethylation even during detraining (following training induced hypertrophy) when exercise was ceased and lean mass returned to baseline (pre-training) levels, identifying them as genes associated with epigenetic memory in skeletal muscle. Importantly, for the first time across the transcriptome and epigenome combined, this study identifies novel differentially methylated genes associated with human skeletal muscle anabolism, hypertrophy and epigenetic memory.
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13
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Dammann K, Khare V, Coleman C, Berdel H, Gasche C. p-21 Activated Kinase as a Molecular Target for Chemoprevention in Diabetes. Geriatrics (Basel) 2018; 3:geriatrics3040073. [PMID: 31011108 PMCID: PMC6371191 DOI: 10.3390/geriatrics3040073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/12/2018] [Accepted: 10/16/2018] [Indexed: 12/26/2022] Open
Abstract
Hypothesis: Anti-diabetic drugs modulate p-21 activated kinase (PAK) signaling. Introduction: Type 2 diabetes mellitus (T2DM) is a chronic inflammatory disease associated with increased cancer risk. PAK signaling is implicated in cellular homeostasis when regulated, and cancer when unrestrained. Recent reports provided a role for PAK signaling in glucose homeostasis, but the role of PAKs in the pathogenesis of T2DM is unknown. Here, we performed a mini-meta-analysis to explore if anti-diabetic drugs modify PAK signaling pathways, and provide insight regarding modulation of these pathways, to potentially reduce diabetes-associated cancer risk. Methods: PAK interacting partners in T2DM were identified using the online STRING database. Correlation studies were performed via systematic literature review to understand the effect of anti-diabetic drugs on PAK signaling. A mini-meta-analysis correlated multiple clinical studies and revealed the overall clinical response rate and percentage of adverse events in piogliazone (n = 53) and metformin (n = 91) treated patients with PAK-associated diseases. Results: A total of 30 PAK interacting partners were identified (10: reduced beta-cell mass; 10: beta-cell dysfunction; 10: obesity-insulin resistance), which were highly associated with Wnt, and G-protein signaling. The anti-diabetic drug metformin activated signaling pathways upstream; whereas pioglitazone inhibited pathways downstream of PAK. Overall, clinical response upon pioglitazone treatment was 53%. Seventy-nine percent of pioglitazone and 75% of metformin treated patients had adverse events. Pioglitazone reduced molecular-PAK biomarkers of proliferation (Ki67 and CyclinD1), and metformin had the opposite effect. Conclusions: PAK signaling in T2DM likely involves Wnt and G-protein signaling, which may be altered by the anti-diabetic drugs metformin and pioglitazone. Apart from the therapeutic limitations of adverse events, pioglitazone may be promising in chemoprevention. However long-term multi-centered studies, which initiate pioglitazone treatment early will be required to fully assess the full potential of these drugs.
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Affiliation(s)
- Kyle Dammann
- Department of Clinical Medicine, Medical University of the Americas, Devens, MA 01434, USA.
| | - Vineeta Khare
- Department of Internal Medicine III, Medical University of Vienna, Vienna 1090, Austria.
| | - Clyde Coleman
- Department of Surgery, University of Kentucky HealthCare, Lexington, KY 40536, USA.
| | - Henrik Berdel
- Department of Acute Care and Trauma Surgery, University of Kentucky HealthCare, Lexington, KY 40536, USA.
| | - Christoph Gasche
- Department of Internal Medicine III, Medical University of Vienna, Vienna 1090, Austria.
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14
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Ferreira LF, Laitano O. Regulation of NADPH oxidases in skeletal muscle. Free Radic Biol Med 2016; 98:18-28. [PMID: 27184955 PMCID: PMC4975970 DOI: 10.1016/j.freeradbiomed.2016.05.011] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 03/31/2016] [Accepted: 05/12/2016] [Indexed: 12/20/2022]
Abstract
The only known function of NAD(P)H oxidases is to produce reactive oxygen species (ROS). Skeletal muscles express three isoforms of NAD(P)H oxidases (Nox1, Nox2, and Nox4) that have been identified as critical modulators of redox homeostasis. Nox2 acts as the main source of skeletal muscle ROS during contractions, participates in insulin signaling and glucose transport, and mediates the myocyte response to osmotic stress. Nox2 and Nox4 contribute to skeletal muscle abnormalities elicited by angiotensin II, muscular dystrophy, heart failure, and high fat diet. Our review addresses the expression and regulation of NAD(P)H oxidases with emphasis on aspects that are relevant to skeletal muscle. We also summarize: i) the most widely used NAD(P)H oxidases activity assays and inhibitors, and ii) studies that have defined Nox enzymes as protagonists of skeletal muscle redox homeostasis in a variety of health and disease conditions.
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Affiliation(s)
- Leonardo F Ferreira
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
| | - Orlando Laitano
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Universidade Federal do Vale do São Francisco, Petrolina, PE, Brazil
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15
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Satoh T. Molecular mechanisms for the regulation of insulin-stimulated glucose uptake by small guanosine triphosphatases in skeletal muscle and adipocytes. Int J Mol Sci 2014; 15:18677-92. [PMID: 25325535 PMCID: PMC4227239 DOI: 10.3390/ijms151018677] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 09/28/2014] [Accepted: 09/30/2014] [Indexed: 12/11/2022] Open
Abstract
Insulin is a hormone that regulates the blood glucose level by stimulating various physiological responses in its target tissues. In skeletal muscle and adipose tissue, insulin promotes membrane trafficking of the glucose transporter GLUT4 from GLUT4 storage vesicles to the plasma membrane, thereby facilitating the uptake of glucose from the circulation. Detailed mechanisms underlying insulin-dependent intracellular signal transduction for glucose uptake remain largely unknown. In this article, I give an overview on the recently identified signaling network involving Rab, Ras, and Rho family small guanosine triphosphatases (GTPases) that regulates glucose uptake in insulin-responsive tissues. In particular, the regulatory mechanisms for these small GTPases and the cross-talk between protein kinase and small GTPase cascades are highlighted.
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Affiliation(s)
- Takaya Satoh
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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16
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Sylow L, Møller LLV, Kleinert M, Richter EA, Jensen TE. Rac1--a novel regulator of contraction-stimulated glucose uptake in skeletal muscle. Exp Physiol 2014; 99:1574-80. [PMID: 25239922 DOI: 10.1113/expphysiol.2014.079194] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Muscle contraction stimulates muscle glucose uptake by facilitating translocation of glucose transporter 4 from intracellular locations to the cell surface, which allows for diffusion of glucose into the myofibres. The intracellular mechanisms regulating this process are not well understood. The GTPase Rac1 has, until recently, been investigated only with regard to its involvement in insulin-stimulated glucose uptake. However, we recently found that Rac1 is activated during muscle contraction and exercise in mice and humans. Remarkably, Rac1 seems to be necessary for exercise and contraction-stimulated glucose uptake in skeletal muscle, because muscle-specific Rac1 knockout mice display reduced ex vivo contraction- and in vivo exercise-stimulated glucose uptake. The molecular mechanism by which Rac1 regulates glucose uptake is presently unknown. However, recent studies link Rac1 to the actin cytoskeleton, the small GTPase RalA and/or free radical production, which have previously been shown to be regulators of glucose uptake in muscle. We propose a model in which Rac1 is activated by contraction- and exercise-induced mechanical stress signals and that Rac1 in conjunction with other signalling regulates glucose uptake during muscle contraction and exercise.
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Affiliation(s)
- Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Lisbeth L V Møller
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Maximilian Kleinert
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
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17
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Barnea M, Cohen-Yogev T, Chapnik N, Madar Z, Froy O. Effect of metformin and lipid emulsion on the circadian gene expression in muscle cells. Int J Biochem Cell Biol 2014; 53:151-61. [DOI: 10.1016/j.biocel.2014.05.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 03/23/2014] [Accepted: 05/07/2014] [Indexed: 12/16/2022]
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18
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Onselaer MB, Oury C, Hunter RW, Eeckhoudt S, Barile N, Lecut C, Morel N, Viollet B, Jacquet LM, Bertrand L, Sakamoto K, Vanoverschelde JL, Beauloye C, Horman S. The Ca(2+) /calmodulin-dependent kinase kinase β-AMP-activated protein kinase-α1 pathway regulates phosphorylation of cytoskeletal targets in thrombin-stimulated human platelets. J Thromb Haemost 2014; 12:973-86. [PMID: 24655923 DOI: 10.1111/jth.12568] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND Platelet activation requires sweeping morphologic changes, supported by contraction and remodeling of the platelet actin cytoskeleton. In various other cell types, AMP-activated protein kinase (AMPK) controls the phosphorylation state of cytoskeletal targets. OBJECTIVE To determine whether AMPK is activated during platelet aggregation and contributes to the control of cytoskeletal targets. RESULTS We found that AMPK-α1 was mainly activated by thrombin, and not by other platelet agonists, in purified human platelets. Thrombin activated AMPK-α1 ex vivo via a Ca(2+) /calmodulin-dependent kinase kinase β (CaMKKβ)-dependent pathway. Pharmacologic inhibition of CaMKKβ blocked thrombin-induced platelet aggregation and counteracted thrombin-induced phosphorylation of several cytoskeletal proteins, namely, regulatory myosin light chains (MLCs), cofilin, and vasodilator-stimulated phosphoprotein (VASP), three key elements involved in actin cytoskeletal contraction and polymerization. Platelets isolated from mice lacking AMPK-α1 showed reduced aggregation in response to thrombin, and this was associated with defects in MLC, cofilin and VASP phosphorylation and actin polymerization. More importantly, we show, for the first time, that the AMPK pathway is activated in platelets of patients undergoing major cardiac surgery, in a heparin-sensitive manner. CONCLUSION AMPK-α1 is activated by thrombin in human platelets. It controls the phosphorylation of key cytoskeletal targets and actin cytoskeletal remodeling during platelet aggregation.
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Affiliation(s)
- M-B Onselaer
- Institut de Recherche Expérimentale et Clinique (IREC), Pôle de Recherche Cardiovasculaire, Université catholique de Louvain, Brussels, Belgium
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19
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Abstract
Insulin is secreted into blood vessels from β cells of pancreatic islets in response to high blood glucose levels. Insulin stimulates an array of physiological responses in target tissues, including liver, skeletal muscle, and adipose tissue, thereby reducing the blood glucose level. Insulin-dependent glucose uptake in skeletal muscle and adipose tissue is primarily mediated by the redistribution of the glucose transporter type 4 from intracellular storage sites to the plasma membrane. Evidence for the participation of the Rho family GTPase Rac1 in glucose uptake signaling in skeletal muscle has emerged from studies using cell cultures and genetically engineered mice. Herein, recent progress in understanding the function and regulation of Rac1, especially the cross-talk with the protein kinase Akt2, is highlighted. In addition, the role for another Rho family member TC10 and its regulatory mechanism in adipocyte insulin signaling are described.
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Affiliation(s)
- Takaya Satoh
- Laboratory of Cell Biology; Department of Biological Science; Graduate School of Science; Osaka Prefecture University; Osaka, Japan
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