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Munoz M, Solis C, McCann M, Park J, Rafael-Clyke K, Chowdhury SAK, Jiang Y, Rosas PC. P21-activated kinase-1 signaling is required to preserve adipose tissue homeostasis and cardiac function. Mol Cell Biochem 2024:10.1007/s11010-024-04968-4. [PMID: 38430300 DOI: 10.1007/s11010-024-04968-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 02/13/2024] [Indexed: 03/03/2024]
Abstract
While P21-activated kinase-1 (PAK1) has been extensively studied in relation to cardiovascular health and glucose metabolism, its roles within adipose tissue and cardiometabolic diseases are less understood. In this study, we explored the effects of PAK1 deletion on energy balance, adipose tissue homeostasis, and cardiac function utilizing a whole-body PAK1 knockout (PAK1-/-) mouse model. Our findings revealed that body weight differences between PAK1-/- and WT mice emerged at 9 weeks of age, with further increases observed at 12 weeks. Furthermore, PAK1-/- mice displayed increased fat mass and decreased lean mass at 12 weeks, indicating a shift towards adiposity. In conjunction with the increased body weight, PAK1-/- mice had increased food intake and reduced energy expenditure. At a mechanistic level, PAK1 deletion boosted the expression of lipogenic markers while diminishing thermogenic markers expression in adipose tissues, contributing to reduced energy expenditure and the overall obesogenic phenotype. Moreover, our findings highlighted a significant impact on cardiac function following PAK1 deletion, including alterations in calcium kinetics and compromised systolic and lusitropy functions. In summary, our study emphasizes the significant role of PAK1 in weight regulation and cardiac function, enriching our comprehension of heart health and metabolism. These findings could potentially facilitate the identification of novel therapeutic targets in cardiometabolic diseases.
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Affiliation(s)
- Marcos Munoz
- Divison of Endocrinology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Christopher Solis
- Department of Health, Nutrition & Food Sciences, Florida State University, Tallahassee, FL, USA
| | - Maximilian McCann
- Department of Ophthalmology & Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Jooman Park
- Department of Physiology & Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Koreena Rafael-Clyke
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Shamim A K Chowdhury
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Yuwei Jiang
- Department of Physiology & Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Paola C Rosas
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA.
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2
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Cao C, Cai Y, Li Y, Li T, Zhang J, Hu Z, Zhang J. Characterization and comparative transcriptomic analysis of skeletal muscle in female Pekin duck and Hanzhong Ma duck during different growth stages using RNA-seq. Poult Sci 2023; 102:103122. [PMID: 37832186 PMCID: PMC10568565 DOI: 10.1016/j.psj.2023.103122] [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: 06/27/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 10/15/2023] Open
Abstract
Duck is an economically important poultry, and there is currently a major focus on improving its meat quality through breeding. There are wide variations in the growth regulation mechanisms of different duck breeds, that fundamental research on skeletal muscle growth is essential for understanding the regulation of unknown genes. The study aimed to broaden the understanding the duck skeletal muscle development and thereby to improve the performance of domestic ducks. In this study, RNA-seq data from skeletal muscles (breast muscle and leg muscle) of Pekin duck and Hanzhong Ma duck sampled at d 17, 21, and 27 of embryo (E17d, E21d, and E27d), as well as at 6-mo-old following birth (M6), to investigate and compare the mRNA temporal expression profiles and associated pathways that regulate skeletal myogenesis of different duck breeds. There were 331 to 1,440 annotated differentially expressed genes (DEGs) in breast muscle and 380 to 1,790 annotated DEGs in leg muscle from different databases between 2 duck breeds. Gene ontology (GO) enrichment in skeletal muscles indicated that these DEGs were mainly involved in biosynthetic process, developmental process, regulation of protein metabolic process and regulation of gene expression. KEGG analysis in skeletal muscles showed that a total of 41 DEGs were mapped to 7 KEGG pathways, including ECM-receptor interaction, focal adhesion, carbon metabolism, regulation of actin cytoskeleton, calcium signaling pathway, biosynthesis of amino acids and PPAR signaling pathway. The differential expression of 8 selected DEGs was verified by qRT-PCR, and the results were consistent with RNA-seq data. The identified DEGs, such as SDC, SPP1, PAK1, MYL9, PGK1, NOS1, PHGDH, TNNT2, FN1, and AQP4, were specially highlighted, indicating their associations with muscle development in the Pekin duck and Hanzhong Ma duck. This study provides a basis for revealing the differences in skeletal muscle development between Pekin duck and Hanzhong Ma duck.
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Affiliation(s)
- Chang Cao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Yingjie Cai
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Yuxiao Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Tao Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Jiqiao Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Zhigang Hu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Jianqin Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, PR China.
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3
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Tokarz VL, Mylvaganam S, Klip A. Palmitate-induced insulin resistance causes actin filament stiffness and GLUT4 mis-sorting without altered Akt signalling. J Cell Sci 2023; 136:jcs261300. [PMID: 37815440 DOI: 10.1242/jcs.261300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/25/2023] [Indexed: 10/11/2023] Open
Abstract
Skeletal muscle insulin resistance, a major contributor to type 2 diabetes, is linked to the consumption of saturated fats. This insulin resistance arises from failure of insulin-induced translocation of glucose transporter type 4 (GLUT4; also known as SLC2A4) to the plasma membrane to facilitate glucose uptake into muscle. The mechanisms of defective GLUT4 translocation are poorly understood, limiting development of insulin-sensitizing therapies targeting muscle glucose uptake. Although many studies have identified early insulin signalling defects and suggest that they are responsible for insulin resistance, their cause-effect has been debated. Here, we find that the saturated fat palmitate (PA) causes insulin resistance owing to failure of GLUT4 translocation in skeletal muscle myoblasts and myotubes without impairing signalling to Akt2 or AS160 (also known as TBC1D4). Instead, PA altered two basal-state events: (1) the intracellular localization of GLUT4 and its sorting towards a perinuclear storage compartment, and (2) actin filament stiffness, which prevents Rac1-dependent actin remodelling. These defects were triggered by distinct mechanisms, respectively protein palmitoylation and endoplasmic reticulum (ER) stress. Our findings highlight that saturated fats elicit muscle cell-autonomous dysregulation of the basal-state machinery required for GLUT4 translocation, which 'primes' cells for insulin resistance.
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Affiliation(s)
- Victoria L Tokarz
- Department of Physiology, University of Toronto, Ontario, M5S 1A8, Canada
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Sivakami Mylvaganam
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
- Department of Biochemistry, University of Toronto, Ontario, M5S 1A8, Canada
| | - Amira Klip
- Department of Physiology, University of Toronto, Ontario, M5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Ontario, M5S 1A8, Canada
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4
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Balakrishnan R, Garcia PA, Veluthakal R, Huss JM, Hoolachan JM, Thurmond DC. Toward Ameliorating Insulin Resistance: Targeting a Novel PAK1 Signaling Pathway Required for Skeletal Muscle Mitochondrial Function. Antioxidants (Basel) 2023; 12:1658. [PMID: 37759961 PMCID: PMC10525748 DOI: 10.3390/antiox12091658] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 09/29/2023] Open
Abstract
The p21-activated kinase 1 (PAK1) is required for insulin-stimulated glucose uptake in skeletal muscle cells. However, whether PAK1 regulates skeletal muscle mitochondrial function, which is a central determinant of insulin sensitivity, is unknown. Here, the effect of modulating PAK1 levels (knockdown via siRNA, overexpression via adenoviral transduction, and/or inhibition of activation via IPA3) on mitochondrial function was assessed in normal and/or insulin-resistant rat L6.GLUT4myc and human muscle (LHCN-M2) myotubes. Human type 2 diabetes (T2D) and non-diabetic (ND) skeletal muscle samples were also used for validation of the identified signaling elements. PAK1 depletion in myotubes decreased mitochondrial copy number, respiration, altered mitochondrial structure, downregulated PGC1α (a core regulator of mitochondrial biogenesis and oxidative metabolism) and PGC1α activators, p38 mitogen-activated protein kinase (p38MAPK) and activating transcription factor 2 (ATF2). PAK1 enrichment in insulin-resistant myotubes improved mitochondrial function and rescued PGC1α expression levels. Activated PAK1 was localized to the cytoplasm, and PAK1 enrichment concurrent with p38MAPK inhibition did not increase PGC1α levels. PAK1 inhibition and enrichment also modified nuclear phosphorylated-ATF2 levels. T2D human samples showed a deficit for PGC1α, and PAK1 depletion in LHCN-M2 cells led to reduced mitochondrial respiration. Overall, the results suggest that PAK1 regulates muscle mitochondrial function upstream of the p38MAPK/ATF2/PGC1α-axis pathway.
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Affiliation(s)
- Rekha Balakrishnan
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Pablo A. Garcia
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Janice M. Huss
- School of Medicine, Washington University, 660 S Euclid Ave, St. Louis, MO 63110, USA;
| | - Joseph M. Hoolachan
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope Beckman Research Institute, 1500 E Duarte Road, Duarte, CA 91010, USA; (R.B.); (R.V.)
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5
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Møller LLV, Ali MS, Davey J, Raun SH, Andersen NR, Long JZ, Qian H, Jeppesen JF, Henriquez-Olguin C, Frank E, Jensen TE, Højlund K, Wojtaszewski JFP, Nielsen J, Chiu TT, Jedrychowski MP, Gregorevic P, Klip A, Richter EA, Sylow L. The Rho guanine dissociation inhibitor α inhibits skeletal muscle Rac1 activity and insulin action. Proc Natl Acad Sci U S A 2023; 120:e2211041120. [PMID: 37364105 PMCID: PMC10318982 DOI: 10.1073/pnas.2211041120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 05/22/2023] [Indexed: 06/28/2023] Open
Abstract
The molecular events governing skeletal muscle glucose uptake have pharmacological potential for managing insulin resistance in conditions such as obesity, diabetes, and cancer. With no current pharmacological treatments to target skeletal muscle insulin sensitivity, there is an unmet need to identify the molecular mechanisms that control insulin sensitivity in skeletal muscle. Here, the Rho guanine dissociation inhibitor α (RhoGDIα) is identified as a point of control in the regulation of insulin sensitivity. In skeletal muscle cells, RhoGDIα interacted with, and thereby inhibited, the Rho GTPase Rac1. In response to insulin, RhoGDIα was phosphorylated at S101 and Rac1 dissociated from RhoGDIα to facilitate skeletal muscle GLUT4 translocation. Accordingly, siRNA-mediated RhoGDIα depletion increased Rac1 activity and elevated GLUT4 translocation. Consistent with RhoGDIα's inhibitory effect, rAAV-mediated RhoGDIα overexpression in mouse muscle decreased insulin-stimulated glucose uptake and was detrimental to whole-body glucose tolerance. Aligning with RhoGDIα's negative role in insulin sensitivity, RhoGDIα protein content was elevated in skeletal muscle from insulin-resistant patients with type 2 diabetes. These data identify RhoGDIα as a clinically relevant controller of skeletal muscle insulin sensitivity and whole-body glucose homeostasis, mechanistically by modulating Rac1 activity.
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Affiliation(s)
- Lisbeth L. V. Møller
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Mona S. Ali
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Jonathan Davey
- The Centre for Muscle Research, Department of Physiology, The University of Melbourne, Parkville, VIC3010, Australia
| | - Steffen H. Raun
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Nicoline R. Andersen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Jonathan Z. Long
- Department of Pathology, Stanford University School of Medicine and Stanford, Stanford University, Stanford, CA94305
| | - Hongwei Qian
- The Centre for Muscle Research, Department of Physiology, The University of Melbourne, Parkville, VIC3010, Australia
| | - Jacob F. Jeppesen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Carlos Henriquez-Olguin
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, 7501015Santiago, Chile
| | - Emma Frank
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Thomas E. Jensen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Kurt Højlund
- Steno Diabetes Center Odense, Odense University Hospital, 5000Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, 5000Odense C, Denmark
- Department of Molecular Medicine, University of Southern Denmark, 5000Odense C, Denmark
| | - Jørgen F. P. Wojtaszewski
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, 5230Odense M, Denmark
| | - Tim T. Chiu
- Cell Biology Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Physiology, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Paediatrics, University of Toronto, Toronto, ONM5S 1A1, Canada
| | - Mark P. Jedrychowski
- Department of Cell Biology, Harvard Medical School, Boston, MA02115
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA02215
| | - Paul Gregorevic
- The Centre for Muscle Research, Department of Physiology, The University of Melbourne, Parkville, VIC3010, Australia
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Physiology, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Paediatrics, University of Toronto, Toronto, ONM5S 1A1, Canada
| | - Erik A. Richter
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Lykke Sylow
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
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6
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Ramos-Alvarez I, Lee L, Jensen RT. Cofilin activation in pancreatic acinar cells plays a pivotal convergent role for mediating CCK-stimulated enzyme secretion and growth. Front Physiol 2023; 14:1147572. [PMID: 37138671 PMCID: PMC10149936 DOI: 10.3389/fphys.2023.1147572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/05/2023] [Indexed: 05/05/2023] Open
Abstract
Introduction: The actin regulatory protein, cofilin plays a key signaling role in many cells for numerous cellular responses including in proliferation, development, motility, migration, secretion and growth. In the pancreas it is important in islet insulin secretion, growth of pancreatic cancer cells and in pancreatitis. However, there are no studies on its role or activation in pancreatic acinar cells. Methods: To address this question, we studied the ability of CCK to activate cofilin in pancreatic acinar cells, AR42J cells and CCK1-R transfected Panc-1 cells, the signaling cascades involved and its effect on enzyme secretion and MAPK activation, a key mediator of pancreatic growth. Results: CCK (0.3 and 100 nM), TPA, carbachol, Bombesin, secretin and VIP decreased phospho-cofilin (i.e., activate cofilin) and both phospho-kinetic and inhibitor studies of cofilin, LIM kinase (LIMK) and Slingshot Protein Phosphatase (SSH1) demonstrated these conventional activators of cofilin were not involved. Serine phosphatases inhibitors (calyculin A and okadaic acid), however inhibited CCK/TPA-cofilin activation. Studies of various CCK-activated signaling cascades showed activation of PKC/PKD, Src, PAK4, JNK, ROCK mediated cofilin activation, but not PI3K, p38, or MEK. Furthermore, using both siRNA and cofilin inhibitors, cofilin activation was shown to be essential for CCK-mediated enzyme secretion and MAPK activation. Conclusion: These results support the conclusion that cofilin activation plays a pivotal convergent role for various cell signaling cascades in CCK mediated growth/enzyme secretion in pancreatic acini.
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Affiliation(s)
- Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- National Kyushu Cancer Center, Department of Hepato-Biliary-Pancreatology, Fukuoka, Japan
| | - Robert T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: Robert T. Jensen,
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7
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Liu S, Qi R, Zhang J, Zhang C, Chen L, Yao Z, Niu W. Kalirin mediates Rac1 activation downstream of calcium/calmodulin-dependent protein kinase II to stimulate glucose uptake during muscle contraction. FEBS Lett 2022; 596:3159-3175. [PMID: 35716086 DOI: 10.1002/1873-3468.14428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 04/14/2022] [Accepted: 05/16/2022] [Indexed: 01/14/2023]
Abstract
In this study, we investigated the role of calcium/calmodulin-dependent protein kinase II (CaMKII) in contraction-stimulated glucose uptake in skeletal muscle. C2C12 myotubes were contracted by electrical pulse stimulation (EPS), and treadmill running was used to exercise mice. The activities of CaMKII, the small G protein Rac1, and the Rac1 effector kinase PAK1 were elevated in muscle by running exercise or EPS, while they were lowered by the CaMKII inhibitor KN-93 and/or small interfering RNA (siRNA)-mediated knockdown. EPS induced the mRNA and protein expression of the Rac1-GEF Kalirin in a CaMKII-dependent manner. EPS-induced Rac1 activation was lowered by the Kalirin inhibitor ITX3 or siRNA-mediated Kalirin knockdown. KN-93, ITX3, and siRNA-mediated Kalirin knockdown reduced EPS-induced glucose uptake. These findings define a CaMKII-Kalirin-Rac1 signaling pathway that contributes to contraction-stimulated glucose uptake in skeletal muscle myotubes and tissue.
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Affiliation(s)
- Sasa Liu
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Rui Qi
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Juan Zhang
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Chang Zhang
- Department of Pharmacy, General Hospital, Tianjin Medical University, China
| | - Liming Chen
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Zhi Yao
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Wenyan Niu
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
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Hwang J, Thurmond DC. Exocytosis Proteins: Typical and Atypical Mechanisms of Action in Skeletal Muscle. Front Endocrinol (Lausanne) 2022; 13:915509. [PMID: 35774142 PMCID: PMC9238359 DOI: 10.3389/fendo.2022.915509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/11/2022] [Indexed: 11/18/2022] Open
Abstract
Insulin-stimulated glucose uptake in skeletal muscle is of fundamental importance to prevent postprandial hyperglycemia, and long-term deficits in insulin-stimulated glucose uptake underlie insulin resistance and type 2 diabetes. Skeletal muscle is responsible for ~80% of the peripheral glucose uptake from circulation via the insulin-responsive glucose transporter GLUT4. GLUT4 is mainly sequestered in intracellular GLUT4 storage vesicles in the basal state. In response to insulin, the GLUT4 storage vesicles rapidly translocate to the plasma membrane, where they undergo vesicle docking, priming, and fusion via the high-affinity interactions among the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) exocytosis proteins and their regulators. Numerous studies have elucidated that GLUT4 translocation is defective in insulin resistance and type 2 diabetes. Emerging evidence also links defects in several SNAREs and SNARE regulatory proteins to insulin resistance and type 2 diabetes in rodents and humans. Therefore, we highlight the latest research on the role of SNAREs and their regulatory proteins in insulin-stimulated GLUT4 translocation in skeletal muscle. Subsequently, we discuss the novel emerging role of SNARE proteins as interaction partners in pathways not typically thought to involve SNAREs and how these atypical functions reveal novel therapeutic targets for combating peripheral insulin resistance and diabetes.
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Affiliation(s)
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute at City of Hope, Duarte, CA, United States
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9
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Wasserman DH. Insulin, Muscle Glucose Uptake, and Hexokinase: Revisiting the Road Not Taken. Physiology (Bethesda) 2022; 37:115-127. [PMID: 34779282 PMCID: PMC8977147 DOI: 10.1152/physiol.00034.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 12/25/2022] Open
Abstract
Research conducted over the last 50 yr has provided insight into the mechanisms by which insulin stimulates glucose transport across the skeletal muscle cell membrane Transport alone, however, does not result in net glucose uptake as free glucose equilibrates across the cell membrane and is not metabolized. Glucose uptake requires that glucose is phosphorylated by hexokinases. Phosphorylated glucose cannot leave the cell and is the substrate for metabolism. It is indisputable that glucose phosphorylation is essential for glucose uptake. Major advances have been made in defining the regulation of the insulin-stimulated glucose transporter (GLUT4) in skeletal muscle. By contrast, the insulin-regulated hexokinase (hexokinase II) parallels Robert Frost's "The Road Not Taken." Here the case is made that an understanding of glucose phosphorylation by hexokinase II is necessary to define the regulation of skeletal muscle glucose uptake in health and insulin resistance. Results of studies from different physiological disciplines that have elegantly described how hexokinase II can be regulated are summarized to provide a framework for potential application to skeletal muscle. Mechanisms by which hexokinase II is regulated in skeletal muscle await rigorous examination.
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Affiliation(s)
- David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
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10
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Merz KE, Tunduguru R, Ahn M, Salunkhe VA, Veluthakal R, Hwang J, Bhattacharya S, McCown EM, Garcia PA, Zhou C, Oh E, Yoder SM, Elmendorf JS, Thurmond DC. Changes in Skeletal Muscle PAK1 Levels Regulate Tissue Crosstalk to Impact Whole Body Glucose Homeostasis. Front Endocrinol (Lausanne) 2022; 13:821849. [PMID: 35222279 PMCID: PMC8881144 DOI: 10.3389/fendo.2022.821849] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 01/13/2022] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle accounts for ~80% of insulin-stimulated glucose uptake. The Group I p21-activated kinase 1 (PAK1) is required for the non-canonical insulin-stimulated GLUT4 vesicle translocation in skeletal muscle cells. We found that the abundances of PAK1 protein and its downstream effector in muscle, ARPC1B, are significantly reduced in the skeletal muscle of humans with type 2 diabetes, compared to the non-diabetic controls, making skeletal muscle PAK1 a candidate regulator of glucose homeostasis. Although whole-body PAK1 knockout mice exhibit glucose intolerance and are insulin resistant, the contribution of skeletal muscle PAK1 in particular was unknown. As such, we developed inducible skeletal muscle-specific PAK1 knockout (skmPAK1-iKO) and overexpression (skmPAK1-iOE) mouse models to evaluate the role of PAK1 in skeletal muscle insulin sensitivity and glucose homeostasis. Using intraperitoneal glucose tolerance and insulin tolerance testing, we found that skeletal muscle PAK1 is required for maintaining whole body glucose homeostasis. Moreover, PAK1 enrichment in GLUT4-myc-L6 myoblasts preserves normal insulin-stimulated GLUT4 translocation under insulin resistance conditions. Unexpectedly, skmPAK1-iKO also showed aberrant plasma insulin levels following a glucose challenge. By applying conditioned media from PAK1-enriched myotubes or myoblasts to β-cells in culture, we established that a muscle-derived circulating factor(s) could enhance β-cell function. Taken together, these data suggest that PAK1 levels in the skeletal muscle can regulate not only skeletal muscle insulin sensitivity, but can also engage in tissue crosstalk with pancreatic β-cells, unveiling a new molecular mechanism by which PAK1 regulates whole-body glucose homeostasis.
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Affiliation(s)
- Karla E. Merz
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Ragadeepthi Tunduguru
- Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Miwon Ahn
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Vishal A. Salunkhe
- Sahlgrenska Academy, Institute of Neuroscience and Physiology, Metabolism Research Unit, University of Gothenburg, Gothenburg, Sweden
| | - Rajakrishnan Veluthakal
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Jinhee Hwang
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Supriyo Bhattacharya
- Division of Translational Bioinformatics, City of Hope, Duarte, CA, United States
| | - Erika M. McCown
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Pablo A. Garcia
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Chunxue Zhou
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Eunjin Oh
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Stephanie M. Yoder
- Global Scientific Communications, Eli Lilly & Company, Indianapolis, IN, United States
| | - Jeffrey S. Elmendorf
- Department of Anatomy, Cell Biology and Physiology, Center for Diabetes and Metabolic Disease, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Debbie C. Thurmond
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
- *Correspondence: Debbie C. Thurmond,
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11
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Kořánová T, Dvořáček L, Grebeňová D, Röselová P, Obr A, Kuželová K. PAK1 and PAK2 in cell metabolism regulation. J Cell Biochem 2021; 123:375-389. [PMID: 34750857 DOI: 10.1002/jcb.30175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 10/15/2021] [Accepted: 10/29/2021] [Indexed: 12/23/2022]
Abstract
P21-activated kinases (PAKs) regulate processes associated with cytoskeletal rearrangements, such as cell division, adhesion, and migration. The possible regulatory role of PAKs in cell metabolism has not been well explored, but increasing evidence suggests that a cell metabolic phenotype is related to cell interactions with the microenvironment. We analyzed the impact of PAK inhibition by small molecule inhibitors, small interfering RNA, or gene knockout on the rates of mitochondrial respiration and aerobic glycolysis. Pharmacological inhibition of PAK group I by IPA-3 induced a strong decrease in metabolic rates in human adherent cancer cell lines, leukemia/lymphoma cell lines, and primary leukemia cells. The immediate effect of FRAX597, which inhibits PAK kinase activity, was moderate, indicating that PAK nonkinase functions are essential for cell metabolism. Selective downregulation or deletion of PAK2 was associated with a shift toward oxidative phosphorylation. In contrast, PAK1 knockout resulted in increased glycolysis. However, the overall metabolic capacity was not substantially reduced by PAK1 or PAK2 deletion, possibly due to partial redundancy in PAK1/PAK2 regulatory roles or to activation of other compensatory mechanisms.
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Affiliation(s)
- Tereza Kořánová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Lukáš Dvořáček
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Dana Grebeňová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Pavla Röselová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Adam Obr
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Kateřina Kuželová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
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12
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Schmeisser J, Verlhac-Trichet V, Madaro A, Lall SP, Torrissen O, Olsen RE. Molecular Mechanism Involved in Carotenoid Metabolism in Post-Smolt Atlantic Salmon: Astaxanthin Metabolism During Flesh Pigmentation and Its Antioxidant Properties. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2021; 23:653-670. [PMID: 34417678 DOI: 10.1007/s10126-021-10055-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
A better understanding of carotenoid dynamics (transport, absorption, metabolism, and deposition) is essential to develop a better strategy to improve astaxanthin (Ax) retention in muscle of Atlantic salmon. To achieve that, a comparison of post-smolt salmon with (+ Ax) or without (- Ax) dietary Ax supplementation was established based on a transcriptomic approach targeting pyloric, hepatic, and muscular tissues. Results in post-smolts showed that the pyloric caeca transcriptome is more sensitive to dietary Ax supplementation compared to the other tissues. Key genes sensitive to Ax supplementation could be identified, such as cd36 in pylorus, agr2 in liver, or fbp1 in muscle. The most modulated genes in pylorus were related to absorption but also metabolism of Ax. Additionally, genes linked to upstream regulation of the ferroptosis pathway were significantly modulated in liver, evoking the involvement of Ax as an antioxidant in this process. Finally, the muscle seemed to be less impacted by dietary Ax supplementation, except for genes related to actin remodelling and glucose homeostasis. In conclusion, the transcriptome data generated from this study showed that Ax dynamics in Atlantic salmon is characterized by a high metabolism during absorption at pyloric caeca level. In liver, a link with a potential of ferroptosis process appears likely via cellular lipid peroxidation. Our data provide insights into a better understanding of molecular mechanisms involved in dietary Ax supplementation, as well as its beneficial effects in preventing oxidative stress and related inflammation in muscle.
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Affiliation(s)
- Jerome Schmeisser
- DSM Nutritional Products - Research Centre of Animal Nutrition and Health, 68305, Saint-Louis Cedex, France.
| | - Viviane Verlhac-Trichet
- DSM Nutritional Products - Research Centre of Animal Nutrition and Health, 68305, Saint-Louis Cedex, France
| | - Angelico Madaro
- Institute of Marine Research, Animal Welfare Science Group, 5984, Matredal, Norway
| | - Santosh P Lall
- Retired From National Research Council of Canada, 1411 Oxford Street, Halifax, Canada
| | - Ole Torrissen
- Institute of Marine Research, Animal Welfare Science Group, 5984, Matredal, Norway
| | - Rolf Erik Olsen
- Institute of Marine Research, Animal Welfare Science Group, 5984, Matredal, Norway
- Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, Norway
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13
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Masson SWC, Woodhead JST, D'Souza RF, Broome SC, MacRae C, Cho HC, Atiola RD, Futi T, Dent JR, Shepherd PR, Merry TL. β-Catenin is required for optimal exercise- and contraction-stimulated skeletal muscle glucose uptake. J Physiol 2021; 599:3897-3912. [PMID: 34180063 DOI: 10.1113/jp281352] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 06/22/2021] [Indexed: 01/14/2023] Open
Abstract
KEY POINTS Loss of β-catenin impairs in vivo and isolated muscle exercise/contraction-stimulated glucose uptake. β-Catenin is required for exercise-induced skeletal muscle actin cytoskeleton remodelling. β-Catenin675 phosphorylation during exercise may be intensity dependent. ABSTRACT The conserved structural protein β-catenin is an emerging regulator of vesicle trafficking in multiple tissues and supports insulin-stimulated glucose transporter 4 (GLUT4) translocation in skeletal muscle by facilitating cortical actin remodelling. Actin remodelling may be a convergence point between insulin and exercise/contraction-stimulated glucose uptake. Here we investigated whether β-catenin is involved in regulating exercise/contraction-stimulated glucose uptake. We report that the muscle-specific deletion of β-catenin induced in adult mice (BCAT-mKO) impairs both exercise- and contraction (isolated muscle)-induced glucose uptake without affecting running performance or canonical exercise signalling pathways. Furthermore, high intensity exercise in mice and contraction of myotubes and isolated muscles led to the phosphorylation of β-cateninS675 , and this was impaired by Rac1 inhibition. Moderate intensity exercise in control and Rac1 muscle-specific knockout mice did not induce muscle β-cateninS675 phosphorylation, suggesting exercise intensity-dependent regulation of β-cateninS675 . Introduction of a non-phosphorylatable S675A mutant of β-catenin into myoblasts impaired GLUT4 translocation and actin remodelling stimulated by carbachol, a Rac1 and RhoA activator. Exercise-induced increases in cross-sectional phalloidin staining (F-actin marker) of gastrocnemius muscle was impaired in muscle from BCAT-mKO mice. Collectively our findings suggest that β-catenin is required for optimal glucose transport in muscle during exercise/contraction, potentially via facilitating actin cytoskeleton remodelling.
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Affiliation(s)
- Stewart W C Masson
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Jonathan S T Woodhead
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Randall F D'Souza
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Sophie C Broome
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Caitlin MacRae
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Hyun C Cho
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Robert D Atiola
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Tumanu Futi
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Jessica R Dent
- Department of Surgery, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Peter R Shepherd
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand.,Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Troy L Merry
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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14
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Barbé C, Loumaye A, Lause P, Ritvos O, Thissen JP. p21-Activated Kinase 1 Is Permissive for the Skeletal Muscle Hypertrophy Induced by Myostatin Inhibition. Front Physiol 2021; 12:677746. [PMID: 34220542 PMCID: PMC8247767 DOI: 10.3389/fphys.2021.677746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/26/2021] [Indexed: 12/16/2022] Open
Abstract
Skeletal muscle, the most abundant tissue in the body, plays vital roles in locomotion and metabolism. Understanding the cellular processes that govern regulation of muscle mass and function represents an essential step in the development of therapeutic strategies for muscular disorders. Myostatin, a member of the TGF-β family, has been identified as a negative regulator of muscle development. Indeed, its inhibition induces an extensive skeletal muscle hypertrophy requiring the activation of Smad 1/5/8 and the Insulin/IGF-I signaling pathway, but whether other molecular mechanisms are involved in this process remains to be determined. Using transcriptomic data from various Myostatin inhibition models, we identified Pak1 as a potential mediator of Myostatin action on skeletal muscle mass. Our results show that muscle PAK1 levels are systematically increased in response to Myostatin inhibition, parallel to skeletal muscle mass, regardless of the Myostatin inhibition model. Using Pak1 knockout mice, we investigated the role of Pak1 in the skeletal muscle hypertrophy induced by different approaches of Myostatin inhibition. Our findings show that Pak1 deletion does not impede the skeletal muscle hypertrophy magnitude in response to Myostatin inhibition. Therefore, Pak1 is permissive for the skeletal muscle mass increase caused by Myostatin inhibition.
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Affiliation(s)
- Caroline Barbé
- Pole of Endocrinology, Diabetes and Nutrition, Institute of Clinical and Experimental Research, Catholic University of Louvain, Brussels, Belgium
| | - Audrey Loumaye
- Pole of Endocrinology, Diabetes and Nutrition, Institute of Clinical and Experimental Research, Catholic University of Louvain, Brussels, Belgium
| | - Pascale Lause
- Pole of Endocrinology, Diabetes and Nutrition, Institute of Clinical and Experimental Research, Catholic University of Louvain, Brussels, Belgium
| | - Olli Ritvos
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jean-Paul Thissen
- Pole of Endocrinology, Diabetes and Nutrition, Institute of Clinical and Experimental Research, Catholic University of Louvain, Brussels, Belgium
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15
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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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16
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Abstract
As the principal tissue for insulin-stimulated glucose disposal, skeletal muscle is a primary driver of whole-body glycemic control. Skeletal muscle also uniquely responds to muscle contraction or exercise with increased sensitivity to subsequent insulin stimulation. Insulin's dominating control of glucose metabolism is orchestrated by complex and highly regulated signaling cascades that elicit diverse and unique effects on skeletal muscle. We discuss the discoveries that have led to our current understanding of how insulin promotes glucose uptake in muscle. We also touch upon insulin access to muscle, and insulin signaling toward glycogen, lipid, and protein metabolism. We draw from human and rodent studies in vivo, isolated muscle preparations, and muscle cell cultures to home in on the molecular, biophysical, and structural elements mediating these responses. Finally, we offer some perspective on molecular defects that potentially underlie the failure of muscle to take up glucose efficiently during obesity and type 2 diabetes.
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17
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Masson SWC, Sorrenson B, Shepherd PR, Merry TL. β-catenin regulates muscle glucose transport via actin remodelling and M-cadherin binding. Mol Metab 2020; 42:101091. [PMID: 33011305 PMCID: PMC7568189 DOI: 10.1016/j.molmet.2020.101091] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/17/2020] [Accepted: 09/24/2020] [Indexed: 12/13/2022] Open
Abstract
Objective Skeletal muscle glucose disposal following a meal is mediated through insulin-stimulated movement of the GLUT4-containing vesicles to the cell surface. The highly conserved scaffold-protein β-catenin is an emerging regulator of vesicle trafficking in other tissues. Here, we investigated the involvement of β-catenin in skeletal muscle insulin-stimulated glucose transport. Methods Glucose homeostasis and transport was investigated in inducible muscle specific β-catenin knockout (BCAT-mKO) mice. The effect of β-catenin deletion and mutation of β-catenin serine 552 on signal transduction, glucose uptake and protein–protein interactions were determined in L6-G4-myc cells, and β-catenin insulin-responsive binding partners were identified via immunoprecipitation coupled to label-free proteomics. Results Skeletal muscle specific deletion of β-catenin impaired whole-body insulin sensitivity and insulin-stimulated glucose uptake into muscle independent of canonical Wnt signalling. In response to insulin, β-catenin was phosphorylated at serine 552 in an Akt-dependent manner, and in L6-G4-myc cells, mutation of β-cateninS552 impaired insulin-induced actin-polymerisation, resulting in attenuated insulin-induced glucose transport and GLUT4 translocation. β-catenin was found to interact with M-cadherin in an insulin-dependent β-cateninS552-phosphorylation dependent manner, and loss of M-cadherin in L6-G4-myc cells attenuated insulin-induced actin-polymerisation and glucose transport. Conclusions Our data suggest that β-catenin is a novel mediator of glucose transport in skeletal muscle and may contribute to insulin-induced actin-cytoskeleton remodelling to support GLUT4 translocation. Deletion of β-catenin from the muscles of adult mice attenuates skeletal muscle glucose uptake. Insulin stimulates phosphorylation of β-cateninS552 by a mechanism involving Akt, and this is required for insulin's effects on both GLUT4 trafficking and actin remodelling. Insulin promotes β-catenin/M-cadherin binding, to support cortical actin remodelling associated with GLUT4 translocation.
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Affiliation(s)
- Stewart W C Masson
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Brie Sorrenson
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Peter R Shepherd
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand; Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Troy L Merry
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand.
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18
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Møller LLV, Jaurji M, Kjøbsted R, Joseph GA, Madsen AB, Knudsen JR, Lundsgaard AM, Andersen NR, Schjerling P, Jensen TE, Krauss RS, Richter EA, Sylow L. Insulin-stimulated glucose uptake partly relies on p21-activated kinase (PAK)2, but not PAK1, in mouse skeletal muscle. J Physiol 2020; 598:5351-5377. [PMID: 32844438 DOI: 10.1113/jp280294] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/24/2020] [Indexed: 12/28/2022] Open
Abstract
KEY POINTS Muscle-specific genetic ablation of p21-activated kinase (PAK)2, but not whole-body PAK1 knockout, impairs glucose tolerance in mice. Insulin-stimulated glucose uptake partly relies on PAK2 in glycolytic extensor digitorum longus muscle By contrast to previous reports, PAK1 is dispensable for insulin-stimulated glucose uptake in mouse muscle. ABSTRACT The group I p21-activated kinase (PAK) isoforms PAK1 and PAK2 are activated in response to insulin in skeletal muscle and PAK1/2 signalling is impaired in insulin-resistant mouse and human skeletal muscle. Interestingly, PAK1 has been suggested to be required for insulin-stimulated glucose transporter 4 translocation in mouse skeletal muscle. Therefore, the present study aimed to examine the role of PAK1 in insulin-stimulated muscle glucose uptake. The pharmacological inhibitor of group I PAKs, IPA-3 partially reduced (-20%) insulin-stimulated glucose uptake in isolated mouse soleus muscle (P < 0.001). However, because there was no phenotype with genetic ablation of PAK1 alone, consequently, the relative requirement for PAK1 and PAK2 in whole-body glucose homeostasis and insulin-stimulated muscle glucose uptake was investigated. Whole-body respiratory exchange ratio was largely unaffected in whole-body PAK1 knockout (KO), muscle-specific PAK2 KO and in mice with combined whole-body PAK1 KO and muscle-specific PAK2 KO. By contrast, glucose tolerance was mildly impaired in mice lacking PAK2 specifically in muscle, but not PAK1 KO mice. Moreover, while PAK1 KO muscles displayed normal insulin-stimulated glucose uptake in vivo and in isolated muscle, insulin-stimulated glucose uptake was slightly reduced in isolated glycolytic extensor digitorum longus muscle lacking PAK2 alone (-18%) or in combination with PAK1 KO (-12%) (P < 0.05). In conclusion, glucose tolerance and insulin-stimulated glucose uptake partly rely on PAK2 in glycolytic mouse muscle, whereas PAK1 is dispensable for whole-body glucose homeostasis and insulin-stimulated muscle glucose uptake.
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Affiliation(s)
- Lisbeth L V Møller
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Merna Jaurji
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus Kjøbsted
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Giselle A Joseph
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Agnete B Madsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jonas R Knudsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Microsystems Laboratory 2, Institute of Microengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Anne-Marie Lundsgaard
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Nicoline R Andersen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Robert S Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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19
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Abstract
The skeletal muscle is the largest organ in the body, by mass. It is also the regulator of glucose homeostasis, responsible for 80% of postprandial glucose uptake from the circulation. Skeletal muscle is essential for metabolism, both for its role in glucose uptake and its importance in exercise and metabolic disease. In this article, we give an overview of the importance of skeletal muscle in metabolism, describing its role in glucose uptake and the diseases that are associated with skeletal muscle metabolic dysregulation. We focus on the role of skeletal muscle in peripheral insulin resistance and the potential for skeletal muscle-targeted therapeutics to combat insulin resistance and diabetes, as well as other metabolic diseases like aging and obesity. In particular, we outline the possibilities and pitfalls of the quest for exercise mimetics, which are intended to target the molecular mechanisms underlying the beneficial effects of exercise on metabolic disease. We also provide a description of the molecular mechanisms that regulate skeletal muscle glucose uptake, including a focus on the SNARE proteins, which are essential regulators of glucose transport into the skeletal muscle. © 2020 American Physiological Society. Compr Physiol 10:785-809, 2020.
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Affiliation(s)
- Karla E. Merz
- Department of Molecular and Cellular Endocrinology, City of Hope Beckman Research Institute, Duarte, California, USA
- The Irell and Manella Graduate School of Biological Sciences, City of Hope, Duarte, California, USA
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, City of Hope Beckman Research Institute, Duarte, California, USA
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20
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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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21
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Scholz M, Weirich KL, Gardel ML, Dinner AR. Tuning molecular motor transport through cytoskeletal filament network organization. SOFT MATTER 2020; 16:2135-2140. [PMID: 32016200 DOI: 10.1039/c9sm01904a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Within cells, crosslinking proteins organize cytoskeletal filaments both temporally and spatially to create dynamic and structurally diverse networks. Molecular motors move on these networks for both force generation and transport processes. How the transport statistics depend on the network architecture remains poorly characterized. Using cross-linking proteins (α-actinin, fimbrin, fascin, or filamin) and purified actin, we create cytoskeletal networks with diverse microscopic architectures. We track the motion of myosin II motor proteins moving on these networks and calculate transport statistics. We observe that motor dynamics change predictably based on the bundling of filaments within the underlying networks and discuss implications for network function.
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Affiliation(s)
- Monika Scholz
- James Franck Institute, The University of Chicago, Chicago, IL 60637, USA. and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
| | - Kimberly L Weirich
- James Franck Institute, The University of Chicago, Chicago, IL 60637, USA. and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
| | - Margaret L Gardel
- James Franck Institute, The University of Chicago, Chicago, IL 60637, USA. and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA and Department of Physics, The University of Chicago, Chicago, IL 60637, USA
| | - Aaron R Dinner
- James Franck Institute, The University of Chicago, Chicago, IL 60637, USA. and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA and Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA
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22
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Báez-Matus X, Figueroa-Cares C, Gónzalez-Jamett AM, Almarza-Salazar H, Arriagada C, Maldifassi MC, Guerra MJ, Mouly V, Bigot A, Caviedes P, Cárdenas AM. Defects in G-Actin Incorporation into Filaments in Myoblasts Derived from Dysferlinopathy Patients Are Restored by Dysferlin C2 Domains. Int J Mol Sci 2019; 21:ijms21010037. [PMID: 31861684 PMCID: PMC6981584 DOI: 10.3390/ijms21010037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/13/2019] [Accepted: 12/16/2019] [Indexed: 12/23/2022] Open
Abstract
Dysferlin is a transmembrane C-2 domain-containing protein involved in vesicle trafficking and membrane remodeling in skeletal muscle cells. However, the mechanism by which dysferlin regulates these cellular processes remains unclear. Since actin dynamics is critical for vesicle trafficking and membrane remodeling, we studied the role of dysferlin in Ca2+-induced G-actin incorporation into filaments in four different immortalized myoblast cell lines (DYSF2, DYSF3, AB320, and ER) derived from patients harboring mutations in the dysferlin gene. As compared with immortalized myoblasts obtained from a control subject, dysferlin expression and G-actin incorporation were significantly decreased in myoblasts from dysferlinopathy patients. Stable knockdown of dysferlin with specific shRNA in control myoblasts also significantly reduced G-actin incorporation. The impaired G-actin incorporation was restored by the expression of full-length dysferlin as well as dysferlin N-terminal or C-terminal regions, both of which contain three C2 domains. DYSF3 myoblasts also exhibited altered distribution of annexin A2, a dysferlin partner involved in actin remodeling. However, dysferlin N-terminal and C-terminal regions appeared to not fully restore such annexin A2 mislocation. Then, our results suggest that dysferlin regulates actin remodeling by a mechanism that does to not involve annexin A2.
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Affiliation(s)
- Ximena Báez-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (X.B.-M.); (C.F.-C.); (A.M.G.-J.); (M.C.M.); (M.J.G.)
| | - Cindel Figueroa-Cares
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (X.B.-M.); (C.F.-C.); (A.M.G.-J.); (M.C.M.); (M.J.G.)
| | - Arlek M. Gónzalez-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (X.B.-M.); (C.F.-C.); (A.M.G.-J.); (M.C.M.); (M.J.G.)
| | - Hugo Almarza-Salazar
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (X.B.-M.); (C.F.-C.); (A.M.G.-J.); (M.C.M.); (M.J.G.)
| | - Christian Arriagada
- Departamento de Anatomía y Medicina Legal, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - María Constanza Maldifassi
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (X.B.-M.); (C.F.-C.); (A.M.G.-J.); (M.C.M.); (M.J.G.)
| | - María José Guerra
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (X.B.-M.); (C.F.-C.); (A.M.G.-J.); (M.C.M.); (M.J.G.)
| | - Vincent Mouly
- Sorbonne Université, Inserm, Institut de Myologie, UMRS 974, Center for Research in Myology, 75013 Paris, France; (V.M.); (A.B.)
| | - Anne Bigot
- Sorbonne Université, Inserm, Institut de Myologie, UMRS 974, Center for Research in Myology, 75013 Paris, France; (V.M.); (A.B.)
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile;
- Centro de Biotecnología y Bioingeniería (CeBiB), Departamento de Ingeniería Química, Biotecnología y Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8370456, Chile
| | - Ana M. Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (X.B.-M.); (C.F.-C.); (A.M.G.-J.); (M.C.M.); (M.J.G.)
- Correspondence: ; Tel.: +56-322-508-052
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23
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Sarshar M, Scribano D, Tranquilli G, Di Pietro M, Filardo S, Zagaglia C, Sessa R, Palamara AT, Ambrosi C. A simple, fast and reliable scan-based technique as a novel approach to quantify intracellular bacteria. BMC Microbiol 2019; 19:252. [PMID: 31718545 PMCID: PMC6849193 DOI: 10.1186/s12866-019-1625-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/24/2019] [Indexed: 12/31/2022] Open
Abstract
Background Quantification of intracellular bacteria is fundamental in many areas of cellular and clinical microbiology to study acute and chronic infections. Therefore, rapid, accurate and low-cost methods represent valuable tools in determining bacterial ability to persist and proliferate within eukaryotic cells. Results Herein, we present the first application of the immunofluorescence In-Cell Western (ICW) assay aimed at quantifying intracellular bacteria in in vitro infection models. The performance of this new approach was evaluated in cell culture infection models using three microorganisms with different lifestyles. Two facultative intracellular bacteria, the fast-growing Shigella flexneri and a persistent strain of Escherichia coli, as well as the obligate intracellular bacterium Chlamydia trachomatis were chosen as bacterial models. The ICW assay was performed in parallel with conventional quantification methods, i.e. colony forming units (CFUs) and inclusion forming units (IFUs). The fluorescence signal intensity values from the ICW assay were highly correlated to CFU/IFUs counting and showed coefficients of determination (R2), ranging from 0,92 to 0,99. Conclusions The ICW assay offers several advantages including sensitivity, reproducibility, high speed, operator-independent data acquisition and overtime stability of fluorescence signals. All these features, together with the simplicity in performance, make this assay particularly suitable for high-throughput screening and diagnostic approaches.
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Affiliation(s)
- Meysam Sarshar
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Laboratory affiliated to Institute Pasteur Italia-Fondazione Cenci Bolognetti, 00185, Rome, Italy.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, 1316943551, Iran
| | - Daniela Scribano
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185, Rome, Italy.,Dani Di Giò Foundation-Onlus, Rome, Italy
| | - Giulia Tranquilli
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185, Rome, Italy
| | - Marisa Di Pietro
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185, Rome, Italy
| | - Simone Filardo
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185, Rome, Italy
| | - Carlo Zagaglia
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185, Rome, Italy
| | - Rosa Sessa
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185, Rome, Italy
| | - Anna Teresa Palamara
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Laboratory affiliated to Institute Pasteur Italia-Fondazione Cenci Bolognetti, 00185, Rome, Italy.,IRCCS San Raffaele Pisana, Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Roma Open University, 00166, Rome, Italy
| | - Cecilia Ambrosi
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185, Rome, Italy. .,IRCCS San Raffaele Pisana, Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Roma Open University, 00166, Rome, Italy.
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24
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Jaiswal N, Gavin MG, Quinn WJ, Luongo TS, Gelfer RG, Baur JA, Titchenell PM. The role of skeletal muscle Akt in the regulation of muscle mass and glucose homeostasis. Mol Metab 2019; 28:1-13. [PMID: 31444134 PMCID: PMC6822261 DOI: 10.1016/j.molmet.2019.08.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/29/2019] [Accepted: 08/01/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE Skeletal muscle insulin signaling is a major determinant of muscle growth and glucose homeostasis. Protein kinase B/Akt plays a prominent role in mediating many of the metabolic effects of insulin. Mice and humans harboring systemic loss-of-function mutations in Akt2, the most abundant Akt isoform in metabolic tissues, are glucose intolerant and insulin resistant. Since the skeletal muscle accounts for a significant amount of postprandial glucose disposal, a popular hypothesis in the diabetes field suggests that a reduction in Akt, specifically in skeletal muscle, leads to systemic glucose intolerance and insulin resistance. Despite this common belief, the specific role of skeletal muscle Akt in muscle growth and insulin sensitivity remains undefined. METHODS We generated multiple mouse models of skeletal muscle Akt deficiency to evaluate the role of muscle Akt signaling in vivo. The effects of these genetic perturbations on muscle mass, glucose homeostasis and insulin sensitivity were assessed using both in vivo and ex vivo assays. RESULTS Surprisingly, mice lacking Akt2 alone in skeletal muscle displayed normal skeletal muscle insulin signaling, glucose tolerance, and insulin sensitivity despite a dramatic reduction in phosphorylated Akt. In contrast, deletion of both Akt isoforms (M-AktDKO) prevented downstream signaling and resulted in muscle atrophy. Despite the absence of Akt signaling, in vivo and ex vivo insulin-stimulated glucose uptake were normal in M-AktDKO mice. Similar effects on insulin sensitivity were observed in mice with prolonged deletion (4 weeks) of both skeletal muscle Akt isoforms selectively in adulthood. Conversely, short term deletion (2 weeks) of skeletal muscle specific Akt in adult muscles impaired insulin tolerance paralleling the effect observed by acute pharmacological inhibition of Akt in vitro. Mechanistically, chronic ablation of Akt induced mitochondrial dysfunction and activation of AMPK, which was required for insulin-stimulated glucose uptake in the absence of Akt. CONCLUSIONS Together, these data indicate that chronic reduction in Akt activity alone in skeletal muscle is not sufficient to induce insulin resistance or prevent glucose uptake in all conditions. Therefore, since insulin-stimulated glucose disposal in skeletal muscle is markedly impaired in insulin-resistant states, we hypothesize that alterations in signaling molecules in addition to skeletal muscle Akt are necessary to perturb glucose tolerance and insulin sensitivity in vivo.
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Affiliation(s)
- N Jaiswal
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - M G Gavin
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - W J Quinn
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - T S Luongo
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - R G Gelfer
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - J A Baur
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Physiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - P M Titchenell
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Physiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
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25
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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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26
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Joseph GA, Hung M, Goel AJ, Hong M, Rieder MK, Beckmann ND, Serasinghe MN, Chipuk JE, Devarakonda PM, Goldhamer DJ, Aldana-Hernandez P, Curtis J, Jacobs RL, Krauss RS. Late-onset megaconial myopathy in mice lacking group I Paks. Skelet Muscle 2019; 9:5. [PMID: 30791960 PMCID: PMC6383276 DOI: 10.1186/s13395-019-0191-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 02/12/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Group I Paks are serine/threonine kinases that function as major effectors of the small GTPases Rac1 and Cdc42, and they regulate cytoskeletal dynamics, cell polarity, and transcription. We previously demonstrated that Pak1 and Pak2 function redundantly to promote skeletal myoblast differentiation during postnatal development and regeneration in mice. However, the roles of Pak1 and Pak2 in adult muscle homeostasis are unknown. Choline kinase β (Chk β) is important for adult muscle homeostasis, as autosomal recessive mutations in CHKβ are associated with two human muscle diseases, megaconial congenital muscular dystrophy and proximal myopathy with focal depletion of mitochondria. METHODS We analyzed mice conditionally lacking Pak1 and Pak2 in the skeletal muscle lineage (double knockout (dKO) mice) over 1 year of age. Muscle integrity in dKO mice was assessed with histological stains, immunofluorescence, electron microscopy, and western blotting. Assays for mitochondrial respiratory complex function were performed, as was mass spectrometric quantification of products of choline kinase. Mice and cultured myoblasts deficient for choline kinase β (Chk β) were analyzed for Pak1/2 phosphorylation. RESULTS dKO mice developed an age-related myopathy. By 10 months of age, dKO mouse muscles displayed centrally-nucleated myofibers, fibrosis, and signs of degeneration. Disease severity occurred in a rostrocaudal gradient, hindlimbs more strongly affected than forelimbs. A distinctive feature of this myopathy was elongated and branched intermyofibrillar (megaconial) mitochondria, accompanied by focal mitochondrial depletion in the central region of the fiber. dKO muscles showed reduced mitochondrial respiratory complex I and II activity. These phenotypes resemble those of rmd mice, which lack Chkβ and are a model for human diseases associated with CHKβ deficiency. Pak1/2 and Chkβ activities were not interdependent in mouse skeletal muscle, suggesting a more complex relationship in regulation of mitochondria and muscle homeostasis. CONCLUSIONS Conditional loss of Pak1 and Pak2 in mice resulted in an age-dependent myopathy with similarity to mice and humans with CHKβ deficiency. Protein kinases are major regulators of most biological processes but few have been implicated in muscle maintenance or disease. Pak1/Pak2 dKO mice offer new insights into these processes.
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Affiliation(s)
- Giselle A Joseph
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Present address: Novartis Institutes for BioMedical Research, 181 Massachusetts Ave, Cambridge, MA, 02139, USA
| | - Margaret Hung
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Aviva J Goel
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Mingi Hong
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Marysia-Kolbe Rieder
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Noam D Beckmann
- Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Madhavika N Serasinghe
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jerry E Chipuk
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Parvathi M Devarakonda
- Department of Molecular & Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - David J Goldhamer
- Department of Molecular & Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - Paulina Aldana-Hernandez
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - Jonathan Curtis
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - René L Jacobs
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - Robert S Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA. .,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.
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27
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Li L, Wang S, Li H, Wan J, Zhou Q, Zhou Y, Zhang C. microRNA-96 protects pancreatic β-cell function by targeting PAK1 in gestational diabetes mellitus. Biofactors 2018; 44:539-547. [PMID: 30536654 DOI: 10.1002/biof.1461] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 12/11/2022]
Abstract
Gestational diabetes mellitus (GDM) is a disease condition in which a woman develops high blood sugar levels during pregnancy, which might be induced by multiple factors. Among those relative factors, microRNA (miRNA) is well-known to be involved in GDM development. In this study, we investigated the role of miRNA in GDM by analyzing miRNA expression profiling in placenta tissues from healthy or GDM pregnancies. We found that miR-96 was the most down-regulated miRNA in GDM samples. Furthermore, miRNA target gene prediction revealed that p21-activated kinase 1 (PAK1) is a potential target of miR-96. Functional assays showed that miR-96 enhanced β-cell function, whereas PAK1 inhibited β-cell function and cell viability. Our findings demonstrate that miR-96 plays a critical role in GDM development by regulating PAK1 expression, insulin secretion, and β-cell function. © 2018 BioFactors, 44(6):539-547, 2018.
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Affiliation(s)
- Lei Li
- Department of Obstetrics and Gynaecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Shan Wang
- Department of Obstetrics and Gynaecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Hongyan Li
- Department of Obstetrics and Gynaecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Jipeng Wan
- Department of Obstetrics and Gynaecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Qian Zhou
- Department of Obstetrics and Gynaecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Yu Zhou
- Department of Obstetrics and Gynaecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
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28
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Salunkhe VA, Veluthakal R, Kahn SE, Thurmond DC. Novel approaches to restore beta cell function in prediabetes and type 2 diabetes. Diabetologia 2018; 61:1895-1901. [PMID: 29947922 PMCID: PMC6070408 DOI: 10.1007/s00125-018-4658-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/14/2018] [Indexed: 12/18/2022]
Abstract
The World Health Organization estimates that diabetes prevalence has risen from 108 million in 1980 to 422 million in 2014, with type 2 diabetes accounting for more than 90% of these cases. Furthermore, the prevalence of prediabetes (impaired fasting glucose and/or impaired glucose tolerance) is more than 40% in some countries and is associated with a global rise in obesity. Therefore it is imperative that we develop new approaches to reduce the development of prediabetes and progression to type 2 diabetes. In this review, we explore the gains made over the past decade by focused efforts to improve insulin secretion by the beta cell or insulin sensitivity of target tissues. We also describe multitasking candidates, which could improve both beta cell dysfunction and peripheral insulin sensitivity. Moreover, we highlight provocative findings indicating that additional glucose regulatory tissues, such as the brain, may be key therapeutic targets. Taken together, the promise of these new multi-faceted approaches reinforces the importance of understanding and tackling type 2 diabetes pathogenesis from a multi-tissue perspective.
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Affiliation(s)
- Vishal A Salunkhe
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd, Duarte, CA, 91010, USA
| | - Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd, Duarte, CA, 91010, USA
| | - Steven E Kahn
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, VA Puget Sound Health Care System and University of Washington, Seattle, WA, USA
| | - Debbie C Thurmond
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd, Duarte, CA, 91010, USA.
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29
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Madsen AB, Knudsen JR, Henriquez-Olguin C, Angin Y, Zaal KJ, Sylow L, Schjerling P, Ralston E, Jensen TE. β-Actin shows limited mobility and is required only for supraphysiological insulin-stimulated glucose transport in young adult soleus muscle. Am J Physiol Endocrinol Metab 2018; 315. [PMID: 29533739 PMCID: PMC6087721 DOI: 10.1152/ajpendo.00392.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Studies in skeletal muscle cell cultures suggest that the cortical actin cytoskeleton is a major requirement for insulin-stimulated glucose transport, implicating the β-actin isoform, which in many cell types is the main actin isoform. However, it is not clear that β-actin plays such a role in mature skeletal muscle. Neither dependency of glucose transport on β-actin nor actin reorganization upon glucose transport have been tested in mature muscle. To investigate the role of β-actin in fully differentiated muscle, we performed a detailed characterization of wild type and muscle-specific β-actin knockout (KO) mice. The effects of the β-actin KO were subtle; however, we confirmed the previously reported decline in running performance of β-actin KO mice compared with wild type during repeated maximal running tests. We also found insulin-stimulated glucose transport into incubated muscles reduced in soleus but not in extensor digitorum longus muscle of young adult mice. Contraction-stimulated glucose transport trended toward the same pattern, but the glucose transport phenotype disappeared in soleus muscles from mature adult mice. No genotype-related differences were found in body composition or glucose tolerance or by indirect calorimetry measurements. To evaluate β-actin mobility in mature muscle, we electroporated green fluorescent protein (GFP)-β-actin into flexor digitorum brevis muscle fibers and measured fluorescence recovery after photobleaching. GFP-β-actin showed limited unstimulated mobility and no changes after insulin stimulation. In conclusion, β-actin is not required for glucose transport regulation in mature mouse muscle under the majority of the tested conditions. Thus, our work reveals fundamental differences in the role of the cortical β-actin cytoskeleton in mature muscle compared with cell culture.
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Affiliation(s)
- Agnete B Madsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Jonas R Knudsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Carlos Henriquez-Olguin
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
- Centro de Estudios Moleculares de la Célula, Instituto de Ciencias Biomédicas, Universidad de Chile ; Laboratory of Exercise Sciences, Clínica MEDS, Santiago , Chile
| | - Yeliz Angin
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Kristien J Zaal
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health , Bethesda, Maryland
| | - Lykke Sylow
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopedic Surgery, Bispebjerg Hospital , Copenhagen , Denmark
- Center of Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Evelyn Ralston
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health , Bethesda, Maryland
| | - Thomas E Jensen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
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Ruby MA, Riedl I, Massart J, Åhlin M, Zierath JR. Protein kinase N2 regulates AMP kinase signaling and insulin responsiveness of glucose metabolism in skeletal muscle. Am J Physiol Endocrinol Metab 2017; 313:E483-E491. [PMID: 28720584 PMCID: PMC5668594 DOI: 10.1152/ajpendo.00147.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/27/2017] [Accepted: 07/13/2017] [Indexed: 12/18/2022]
Abstract
Insulin resistance is central to the development of type 2 diabetes and related metabolic disorders. Because skeletal muscle is responsible for the majority of whole body insulin-stimulated glucose uptake, regulation of glucose metabolism in this tissue is of particular importance. Although Rho GTPases and many of their affecters influence skeletal muscle metabolism, there is a paucity of information on the protein kinase N (PKN) family of serine/threonine protein kinases. We investigated the impact of PKN2 on insulin signaling and glucose metabolism in primary human skeletal muscle cells in vitro and mouse tibialis anterior muscle in vivo. PKN2 knockdown in vitro decreased insulin-stimulated glucose uptake, incorporation into glycogen, and oxidation. PKN2 siRNA increased 5'-adenosine monophosphate-activated protein kinase (AMPK) signaling while stimulating fatty acid oxidation and incorporation into triglycerides and decreasing protein synthesis. At the transcriptional level, PKN2 knockdown increased expression of PGC-1α and SREBP-1c and their target genes. In mature skeletal muscle, in vivo PKN2 knockdown decreased glucose uptake and increased AMPK phosphorylation. Thus, PKN2 alters key signaling pathways and transcriptional networks to regulate glucose and lipid metabolism. Identification of PKN2 as a novel regulator of insulin and AMPK signaling may provide an avenue for manipulation of skeletal muscle metabolism.
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Affiliation(s)
- Maxwell A Ruby
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Isabelle Riedl
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Julie Massart
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Marcus Åhlin
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
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Tunduguru R, Zhang J, Aslamy A, Salunkhe VA, Brozinick JT, Elmendorf JS, Thurmond DC. The actin-related p41ARC subunit contributes to p21-activated kinase-1 (PAK1)-mediated glucose uptake into skeletal muscle cells. J Biol Chem 2017; 292:19034-19043. [PMID: 28972183 DOI: 10.1074/jbc.m117.801340] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/21/2017] [Indexed: 02/04/2023] Open
Abstract
Defects in translocation of the glucose transporter GLUT4 are associated with peripheral insulin resistance, preclinical diabetes, and progression to type 2 diabetes. GLUT4 recruitment to the plasma membrane of skeletal muscle cells requires F-actin remodeling. Insulin signaling in muscle requires p21-activated kinase-1 (PAK1), whose downstream signaling triggers actin remodeling, which promotes GLUT4 vesicle translocation and glucose uptake into skeletal muscle cells. Actin remodeling is a cyclic process, and although PAK1 is known to initiate changes to the cortical actin-binding protein cofilin to stimulate the depolymerizing arm of the cycle, how PAK1 might trigger the polymerizing arm of the cycle remains unresolved. Toward this, we investigated whether PAK1 contributes to the mechanisms involving the actin-binding and -polymerizing proteins neural Wiskott-Aldrich syndrome protein (N-WASP), cortactin, and ARP2/3 subunits. We found that the actin-polymerizing ARP2/3 subunit p41ARC is a PAK1 substrate in skeletal muscle cells. Moreover, co-immunoprecipitation experiments revealed that insulin stimulates p41ARC phosphorylation and increases its association with N-WASP coordinately with the associations of N-WASP with cortactin and actin. Importantly, all of these associations were ablated by the PAK inhibitor IPA3, suggesting that PAK1 activation lies upstream of these actin-polymerizing complexes. Using the N-WASP inhibitor wiskostatin, we further demonstrated that N-WASP is required for localized F-actin polymerization, GLUT4 vesicle translocation, and glucose uptake. These results expand the model of insulin-stimulated glucose uptake in skeletal muscle cells by implicating p41ARC as a new component of the insulin-signaling cascade and connecting PAK1 signaling to N-WASP-cortactin-mediated actin polymerization and GLUT4 vesicle translocation.
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Affiliation(s)
- Ragadeepthi Tunduguru
- From the Departments of Biochemistry and Molecular Biology and.,the Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute of the City of Hope, Duarte, California 91010, and
| | - Jing Zhang
- the Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute of the City of Hope, Duarte, California 91010, and
| | - Arianne Aslamy
- the Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute of the City of Hope, Duarte, California 91010, and.,Cellular and Integrative Physiology, Center for Diabetes and Metabolic Diseases,Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Vishal A Salunkhe
- the Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute of the City of Hope, Duarte, California 91010, and
| | | | - Jeffrey S Elmendorf
- From the Departments of Biochemistry and Molecular Biology and.,Cellular and Integrative Physiology, Center for Diabetes and Metabolic Diseases,Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Debbie C Thurmond
- From the Departments of Biochemistry and Molecular Biology and .,the Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute of the City of Hope, Duarte, California 91010, and.,Cellular and Integrative Physiology, Center for Diabetes and Metabolic Diseases,Indiana University School of Medicine, Indianapolis, Indiana 46202
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Jaldin-Fincati JR, Pavarotti M, Frendo-Cumbo S, Bilan PJ, Klip A. Update on GLUT4 Vesicle Traffic: A Cornerstone of Insulin Action. Trends Endocrinol Metab 2017; 28:597-611. [PMID: 28602209 DOI: 10.1016/j.tem.2017.05.002] [Citation(s) in RCA: 180] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 12/20/2022]
Abstract
Glucose transport is rate limiting for dietary glucose utilization by muscle and fat. The glucose transporter GLUT4 is dynamically sorted and retained intracellularly and redistributes to the plasma membrane (PM) by insulin-regulated vesicular traffic, or 'GLUT4 translocation'. Here we emphasize recent findings in GLUT4 translocation research. The application of total internal reflection fluorescence microscopy (TIRFM) has increased our understanding of insulin-regulated events beneath the PM, such as vesicle tethering and membrane fusion. We describe recent findings on Akt-targeted Rab GTPase-activating proteins (GAPs) (TBC1D1, TBC1D4, TBC1D13) and downstream Rab GTPases (Rab8a, Rab10, Rab13, Rab14, and their effectors) along with the input of Rac1 and actin filaments, molecular motors [myosinVa (MyoVa), myosin1c (Myo1c), myosinIIA (MyoIIA)], and membrane fusion regulators (syntaxin4, munc18c, Doc2b). Collectively these findings reveal novel events in insulin-regulated GLUT4 traffic.
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Affiliation(s)
| | - Martin Pavarotti
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada; IHEM, Universidad Nacional de Cuyo, CONICET, Mendoza 5500, Argentina
| | - Scott Frendo-Cumbo
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Philip J Bilan
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.
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Aslamy A, Thurmond DC. Exocytosis proteins as novel targets for diabetes prevention and/or remediation? Am J Physiol Regul Integr Comp Physiol 2017; 312:R739-R752. [PMID: 28356294 DOI: 10.1152/ajpregu.00002.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/24/2017] [Accepted: 03/24/2017] [Indexed: 12/17/2022]
Abstract
Diabetes remains one of the leading causes of morbidity and mortality worldwide, affecting an estimated 422 million adults. In the US, it is predicted that one in every three children born as of 2000 will suffer from diabetes in their lifetime. Type 2 diabetes results from combinatorial defects in pancreatic β-cell glucose-stimulated insulin secretion and in peripheral glucose uptake. Both processes, insulin secretion and glucose uptake, are mediated by exocytosis proteins, SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complexes, Sec1/Munc18 (SM), and double C2-domain protein B (DOC2B). Increasing evidence links deficiencies in these exocytosis proteins to diabetes in rodents and humans. Given this, emerging studies aimed at restoring and/or enhancing cellular levels of certain exocytosis proteins point to promising outcomes in maintaining functional β-cell mass and enhancing insulin sensitivity. In doing so, new evidence also shows that enhancing exocytosis protein levels may promote health span and longevity and may also harbor anti-cancer and anti-Alzheimer's disease capabilities. Herein, we present a comprehensive review of the described capabilities of certain exocytosis proteins and how these might be targeted for improving metabolic dysregulation.
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Affiliation(s)
- Arianne Aslamy
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | - Debbie C Thurmond
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and .,Department of Molecular and Cellular Endocrinology, Beckman Research Institute of City of Hope, Duarte, California
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Varshney P, Dey CS. Resveratrol regulates neuronal glucose uptake and insulin sensitivity via P21-activated kinase 2 (PAK2). Biochem Biophys Res Commun 2017; 485:372-378. [PMID: 28216158 DOI: 10.1016/j.bbrc.2017.02.070] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 02/13/2017] [Indexed: 02/06/2023]
Abstract
We have recently reported P21-activated kinase 2 (PAK2), a serine/threonine kinase as a negative regulator of neuronal glucose uptake and insulin sensitivity. Resveratrol (RSV), a natural polyphenol with anti-oxidative, anti-inflammatory and anti-diabetic properties, regulates PAK2 activity in HepG2 and ESC-B5 cell apoptosis. However, regulation of PAK2 by RSV in neuronal insulin signaling pathway, if any, is still unknown. In the present study, RSV treatment significantly increased PAK2 activity under insulin-sensitive and insulin-resistant condition, along with a marked decrease in glucose uptake in differentiated N2A cells. Pretreatment with AMPK inhibitor, followed by RSV treatment resulted in reduction in PAK2 activity whereas glucose uptake showed an increase. However, pretreatment with Akt inhibitor and then RSV exposure significantly increased PAK2 activity, with a corresponding decrease in glucose uptake. RSV treatment increased AMPK activity and decreased Akt activity. In conclusion, RSV negatively regulates neuronal glucose uptake and insulin sensitivity via PAK2.
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Affiliation(s)
- Pallavi Varshney
- Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi 110016, India
| | - Chinmoy Sankar Dey
- Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi 110016, India.
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Tunduguru R, Thurmond DC. Promoting Glucose Transporter-4 Vesicle Trafficking along Cytoskeletal Tracks: PAK-Ing Them Out. Front Endocrinol (Lausanne) 2017; 8:329. [PMID: 29209279 PMCID: PMC5701999 DOI: 10.3389/fendo.2017.00329] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/06/2017] [Indexed: 12/27/2022] Open
Abstract
Glucose is the principal cellular energy source in humans and maintenance of glucose homeostasis is critical for survival. Glucose uptake into peripheral skeletal muscle and adipose tissues requires the trafficking of vesicles containing glucose transporter-4 (GLUT4) from the intracellular storage compartments to the cell surface. Trafficking of GLUT4 storage vesicles is initiated via the canonical insulin signaling cascade in skeletal muscle and fat cells, as well as via exercise-induced contraction in muscle cells. Recent studies have elucidated steps in the signaling cascades that involve remodeling of the cytoskeleton, a process that underpins the mechanical movement of GLUT4 vesicles. This review is focused upon an alternate phosphoinositide-3 kinase-dependent pathway involving Ras-related C3 botulinum toxin substrate 1 signaling through the p21-activated kinase p21-activated kinase 1 and showcases related signaling events that co-regulate both the depolymerization and re-polymerization of filamentous actin. These new insights provide an enriched understanding into the process of glucose transport and yield potential new targets for interventions aimed to improve insulin sensitivity and remediate insulin resistance, pre-diabetes, and the progression to type 2 diabetes.
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Affiliation(s)
- Ragadeepthi Tunduguru
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
- *Correspondence: Debbie C. Thurmond,
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Rapamycin negatively impacts insulin signaling, glucose uptake and uncoupling protein-1 in brown adipocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1929-1941. [PMID: 27686967 DOI: 10.1016/j.bbalip.2016.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/20/2016] [Accepted: 09/22/2016] [Indexed: 11/21/2022]
Abstract
New onset diabetes after transplantation (NODAT) is a metabolic disorder that affects 40% of patients on immunosuppressive agent (IA) treatment, such as rapamycin (also known as sirolimus). IAs negatively modulate insulin action in peripheral tissues including skeletal muscle, liver and white fat. However, the effects of IAs on insulin sensitivity and thermogenesis in brown adipose tissue (BAT) have not been investigated. We have analyzed the impact of rapamycin on insulin signaling, thermogenic gene-expression and mitochondrial respiration in BAT. Treatment of brown adipocytes with rapamycin for 16h significantly decreased insulin receptor substrate 1 (IRS1) protein expression and insulin-mediated protein kinase B (Akt) phosphorylation. Consequently, both insulin-induced glucose transporter 4 (GLUT4) translocation to the plasma membrane and glucose uptake were decreased. Early activation of the N-terminal Janus activated kinase (JNK) was also observed, thereby increasing IRS1 Ser 307 phosphorylation. These effects of rapamycin on insulin signaling in brown adipocytes were partly prevented by a JNK inhibitor. In vivo treatment of rats with rapamycin for three weeks abolished insulin-mediated Akt phosphorylation in BAT. Rapamycin also inhibited norepinephrine (NE)-induced lipolysis, the expression of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and uncoupling protein (UCP)-1 in brown adipocytes. Importantly, basal mitochondrial respiration, proton leak and maximal respiratory capacity were significantly decreased in brown adipocytes treated with rapamycin. In conclusion, we demonstrate, for the first time the important role of brown adipocytes as target cells of rapamycin, suggesting that insulin resistance in BAT might play a major role in NODAT development.
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Varshney P, Dey CS. P21-activated kinase 2 (PAK2) regulates glucose uptake and insulin sensitivity in neuronal cells. Mol Cell Endocrinol 2016; 429:50-61. [PMID: 27040307 DOI: 10.1016/j.mce.2016.03.035] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/25/2016] [Accepted: 03/29/2016] [Indexed: 12/15/2022]
Abstract
P21-activated kinases (PAKs) are recently reported as important players of insulin signaling and glucose homeostasis in tissues like muscle, pancreas and liver. However, their role in neuronal insulin signaling is still unknown. Present study reports the involvement of PAK2 in neuronal insulin signaling, glucose uptake and insulin resistance. Irrespective of insulin sensitivity, insulin stimulation decreased PAK2 activity. PAK2 downregulation displayed marked enhancement of GLUT4 translocation with increase in glucose uptake whereas PAK2 over-expression showed its reduction. Treatment with Akti-1/2 and wortmannin suggested that Akt and PI3K are mediators of insulin effect on PAK2 and glucose uptake. Rac1 inhibition demonstrated decreased PAK2 activity while inhibition of PP2A resulted in increased PAK2 activity, with corresponding changes in glucose uptake. Taken together, present study demonstrates an inhibitory role of insulin signaling (via PI3K-Akt) and PP2A on PAK2 activity and establishes PAK2 as a Rac1-dependent negative regulator of neuronal glucose uptake and insulin sensitivity.
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Affiliation(s)
- Pallavi Varshney
- Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi 110016, India
| | - Chinmoy Sankar Dey
- Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi 110016, India.
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Veluthakal R, Tunduguru R, Arora DK, Sidarala V, Syeda K, Vlaar CP, Thurmond DC, Kowluru A. VAV2, a guanine nucleotide exchange factor for Rac1, regulates glucose-stimulated insulin secretion in pancreatic beta cells. Diabetologia 2015. [PMID: 26224100 PMCID: PMC4591202 DOI: 10.1007/s00125-015-3707-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
AIMS/HYPOTHESIS Rho GTPases (Ras-related C3 botulinum toxin substrate 1 [Rac1] and cell division cycle 42 [Cdc42]) have been shown to regulate glucose-stimulated insulin secretion (GSIS) via cytoskeletal remodelling, trafficking and fusion of insulin-secretory granules with the plasma membrane. GTP loading of these G proteins, which is facilitated by GDP/GTP exchange factors, is a requisite step in the regulation of downstream effector proteins. Guanine nucleotide exchange factor VAV2 (VAV2), a member of the Dbl family of proteins, has been identified as one of the GDP/GTP exchange factors for Rac1. Despite recent evidence on the regulatory roles of VAV2 in different cell types, roles of this guanine nucleotide exchange factor in the signalling events leading to GSIS remain undefined. Using immunological, short interfering RNA (siRNA), pharmacological and microscopic approaches we investigated the role of VAV2 in GSIS from islet beta cells. METHODS Co-localisation of Rac1 and VAV2 was determined by Triton X-114 phase partition and confocal microscopy. Glucose-induced actin remodelling was quantified by live cell imaging using the LifeAct-GFP fluorescent biosensor. Rac1 activation was determined by G protein linked immunosorbent assay (G-LISA). RESULTS Western blotting indicated that VAV2 is expressed in INS-1 832/13 beta cells, normal rat islets and human islets. Vav2 siRNA markedly attenuated GSIS in INS-1 832/13 cells. Ehop-016, a newly discovered small molecule inhibitor of the VAV2-Rac1 interaction, or siRNA-mediated knockdown of VAV2 markedly attenuated glucose-induced Rac1 activation and GSIS in INS-1 832/13 cells. Pharmacological findings were recapitulated in primary rat islets. A high glucose concentration promoted co-localisation of Rac1 and VAV2. Real-time imaging in live cells indicated a significant inhibition of glucose-induced cortical actin remodelling by Ehop-016. CONCLUSIONS/INTERPRETATION Our data provide the first evidence to implicate VAV2 in glucose-induced Rac1 activation, actin remodelling and GSIS in pancreatic beta cells.
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Affiliation(s)
- Rajakrishnan Veluthakal
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ragadeepthi Tunduguru
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Daleep Kumar Arora
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Vaibhav Sidarala
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA
| | - Khadija Syeda
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA
| | - Cornelis P Vlaar
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Debbie C Thurmond
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Anjaneyulu Kowluru
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA.
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA.
- B-4237 Research Service, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA.
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Rowlands DS, Nelson AR, Raymond F, Metairon S, Mansourian R, Clarke J, Stellingwerff T, Phillips SM. Protein-leucine ingestion activates a regenerative inflammo-myogenic transcriptome in skeletal muscle following intense endurance exercise. Physiol Genomics 2015; 48:21-32. [PMID: 26508702 DOI: 10.1152/physiolgenomics.00068.2015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 10/22/2015] [Indexed: 02/01/2023] Open
Abstract
Protein-leucine supplement ingestion following strenuous endurance exercise accentuates skeletal-muscle protein synthesis and adaptive molecular responses, but the underlying transcriptome is uncharacterized. In a randomized single-blind triple-crossover design, 12 trained men completed 100 min of high-intensity cycling then ingested 70/15/180/30 g protein-leucine-carbohydrate-fat (15LEU), 23/5/180/30 g (5LEU), or 0/0/274/30 g (CON) beverages during the first 90 min of a 240 min recovery period. Vastus lateralis muscle samples (30 and 240 min postexercise) underwent transcriptome analysis by microarray followed by bioinformatic analysis. Gene expression was regulated by protein-leucine in a dose-dependent manner affecting the inflammatory response and muscle growth and development. At 30 min, 15LEU and 5LEU vs. CON activated transcriptome networks with gene-set functions involving cell-cycle arrest (Z-score 2.0-2.7, P < 0.01), leukocyte maturation (1.7, P = 0.007), cell viability (2.4, P = 0.005), promyogenic networks encompassing myocyte differentiation and myogenin (MYOD1, MYOG), and a proteinaceous extracellular matrix, adhesion, and development program correlated with plasma lysine, arginine, tyrosine, taurine, glutamic acid, and asparagine concentrations. High protein-leucine dose (15LEU-5LEU) activated an IL-1I-centered proinflammatory network and leukocyte migration, differentiation, and survival functions (2.0-2.6, <0.001). By 240 min, the protein-leucine transcriptome was anti-inflammatory and promyogenic (IL-6, NF- β, SMAD, STAT3 network inhibition), with overrepresented functions including decreased leukocyte migration and connective tissue development (-1.8-2.4, P < 0.01), increased apoptosis of myeloid and muscle cells (2.2-3.0, P < 0.002), and cell metabolism (2.0-2.4, P < 0.01). The analysis suggests protein-leucine ingestion modulates inflammatory-myogenic regenerative processes during skeletal muscle recovery from endurance exercise. Further cellular and translational research is warranted to validate amino acid-mediated myeloid and myocellular mechanisms within skeletal-muscle functional plasticity.
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Affiliation(s)
- David S Rowlands
- School of Sport and Exercise and Institute of Food Nutrition, and Human Health, Massey University, Wellington, New Zealand; and
| | - Andre R Nelson
- School of Sport and Exercise and Institute of Food Nutrition, and Human Health, Massey University, Wellington, New Zealand; and Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia
| | - Frederic Raymond
- Nestle Research Centre, Lausanne, Switzerland; and Nestlé Institute of Health Sciences, Lausanne, Switzerland
| | - Sylviane Metairon
- Nestle Research Centre, Lausanne, Switzerland; and Nestlé Institute of Health Sciences, Lausanne, Switzerland
| | | | - Jim Clarke
- School of Sport and Exercise and Institute of Food Nutrition, and Human Health, Massey University, Wellington, New Zealand; and
| | - Trent Stellingwerff
- Nestle Research Centre, Lausanne, Switzerland; and Canadian Sport Institute Pacific, Victoria, Canada; and
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Davis RT, Simon JN, Utter M, Mungai P, Alvarez MG, Chowdhury SAK, Heydemann A, Ke Y, Wolska BM, Solaro RJ. Knockout of p21-activated kinase-1 attenuates exercise-induced cardiac remodelling through altered calcineurin signalling. Cardiovasc Res 2015; 108:335-47. [PMID: 26464331 DOI: 10.1093/cvr/cvv234] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 10/03/2015] [Indexed: 01/14/2023] Open
Abstract
AIMS Despite its known cardiovascular benefits, the intracellular signalling mechanisms underlying physiological cardiac growth remain poorly understood. Therefore, the purpose of this study was to investigate a novel role of p21-activated kinase-1 (Pak1) in the regulation of exercise-induced cardiac hypertrophy. METHODS AND RESULTS Wild-type (WT) and Pak1 KO mice were subjected to 6 weeks of treadmill endurance exercise training (ex-training). Cardiac function was assessed via echocardiography, in situ haemodynamics, and the pCa-force relations in skinned fibre preparations at baseline and at the end of the training regimen. Post-translational modifications to the sarcomeric proteins and expression levels of calcium-regulating proteins were also assessed following ex-training. Heart weight/tibia length and echocardiography data revealed that there was marked hypertrophy following ex-training in the WT mice, which was not evident in the KO mice. Additionally, following ex-training, WT mice demonstrated an increase in cardiac contractility, myofilament calcium sensitivity, and phosphorylation of cardiac myosin-binding protein C, cardiac TnT, and tropomyosin compared with KO mice. With ex-training in WT mice, there were also increased protein levels of calcineurin and increased phosphorylation of phospholamban. CONCLUSIONS Our data suggest that Pak1 is essential for adaptive physiological cardiac remodelling and support previous evidence that demonstrates Pak1 signalling is important for cardiac growth and survival.
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Affiliation(s)
- Robert T Davis
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Jillian N Simon
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Megan Utter
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Paul Mungai
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Manuel G Alvarez
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Shamim A K Chowdhury
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Ahlke Heydemann
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Yunbo Ke
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Beata M Wolska
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA Department of Medicine, Section of Cardiology, Center for Cardiovascular Research, University of Illinois, Chicago, IL 60612, USA
| | - R John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
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Arous C, Halban PA. The skeleton in the closet: actin cytoskeletal remodeling in β-cell function. Am J Physiol Endocrinol Metab 2015; 309:E611-20. [PMID: 26286869 DOI: 10.1152/ajpendo.00268.2015] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/11/2015] [Indexed: 01/13/2023]
Abstract
Over the last few decades, biomedical research has considered not only the function of single cells but also the importance of the physical environment within a whole tissue, including cell-cell and cell-extracellular matrix interactions. Cytoskeleton organization and focal adhesions are crucial sensors for cells that enable them to rapidly communicate with the physical extracellular environment in response to extracellular stimuli, ensuring proper function and adaptation. The involvement of the microtubular-microfilamentous cytoskeleton in secretion mechanisms was proposed almost 50 years ago, since when the evolution of ever more sensitive and sophisticated methods in microscopy and in cell and molecular biology have led us to become aware of the importance of cytoskeleton remodeling for cell shape regulation and its crucial link with signaling pathways leading to β-cell function. Emerging evidence suggests that dysfunction of cytoskeletal components or extracellular matrix modification influences a number of disorders through potential actin cytoskeleton disruption that could be involved in the initiation of multiple cellular functions. Perturbation of β-cell actin cytoskeleton remodeling could arise secondarily to islet inflammation and fibrosis, possibly accounting in part for impaired β-cell function in type 2 diabetes. This review focuses on the role of actin remodeling in insulin secretion mechanisms and its close relationship with focal adhesions and myosin II.
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Affiliation(s)
- Caroline Arous
- Department of Genetic Medicine and Development, University of Geneva Medical Center, Geneva, Switzerland
| | - Philippe A Halban
- Department of Genetic Medicine and Development, University of Geneva Medical Center, Geneva, Switzerland
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Kowluru A, Kowluru RA. Protein prenylation in islet β-cell function in health and diabetes: Putting the pieces of the puzzle together. Biochem Pharmacol 2015. [PMID: 26215874 DOI: 10.1016/j.bcp.2015.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Post-translational prenylation involves incorporation of 15-(farnesyl) or 20-(geranylgeranyl) carbon derivatives of mevalonic acid into highly conserved C-terminal cysteines of proteins. The farnesyl transferase (FTase) and the geranylgeranyl transferase (GGTase) mediate incorporation of farnesyl and geranylgeranyl groups, respectively. At least 300 proteins are prenylated in the human genome; the majority of these are implicated in cellular processes including growth, differentiation, cytoskeletal function and vesicle trafficking. From a functional standpoint, isoprenylation is requisite for targeting of modified proteins to relevant cellular compartments for regulation of effector proteins. Pharmacological and molecular biological studies have provided compelling evidence for key roles of this signaling pathway in physiological insulin secretion in normal rodent and human islets. Recent evidence indicates that inhibition of prenylation results in mislocalization of unprenylated proteins, and surprisingly, they remain in active (GTP-bound) conformation. Sustained activation of G proteins has been reported in mice lacking GGTase, suggesting alternate mechanisms for the activation of non-prenylated G proteins. These findings further raise an interesting question if mislocalized, non-prenylated and functionally active G proteins cause cellular pathology since aberrant protein prenylation has been implicated in the onset of cardiovascular disease and diabetes. Herein, we overview the existing evidence to implicate prenylation in islet function and potential defects in this signaling pathways in the diabetic β-cell. We will also identify critical knowledge gaps that need to be addressed for the development of therapeutics to halt defects in these signaling steps in β cells in models of impaired insulin secretion, metabolic stress and diabetes.
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Affiliation(s)
- Anjaneyulu Kowluru
- John D. Dingell VA Medical Center, Detroit, MI 48201, United States; Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, United States.
| | - Renu A Kowluru
- Kresge Eye Institute, Wayne State University, Detroit, MI 48201, United States
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Mikawa T, LLeonart ME, Takaori-Kondo A, Inagaki N, Yokode M, Kondoh H. Dysregulated glycolysis as an oncogenic event. Cell Mol Life Sci 2015; 72:1881-92. [PMID: 25609364 PMCID: PMC11113496 DOI: 10.1007/s00018-015-1840-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/11/2015] [Accepted: 01/13/2015] [Indexed: 02/07/2023]
Abstract
Enhanced glycolysis in cancer, called the Warburg effect, is a well-known feature of cancer metabolism. Recent advances revealed that the Warburg effect is coupled to many other cancer properties, including adaptation to hypoxia and low nutrients, immortalisation, resistance to oxidative stress and apoptotic stimuli, and elevated biomass synthesis. These linkages are mediated by various oncogenic molecules and signals, such as c-Myc, p53, and the insulin/Ras pathway. Furthermore, several regulators of glycolysis have been recently identified as oncogene candidates, including the hypoxia-inducible factor pathway, sirtuins, adenosine monophosphate-activated kinase, glycolytic pyruvate kinase M2, phosphoglycerate mutase, and oncometabolites. The interplay between glycolysis and oncogenic events will be the focus of this review.
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Affiliation(s)
- Takumi Mikawa
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507 Japan
| | - Matilde E. LLeonart
- Department of Pathology, Hospital Vall de’Hebron, Paseo Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Akifumi Takaori-Kondo
- Department of Hematology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507 Japan
- Department of Oncology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507 Japan
| | - Nobuya Inagaki
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507 Japan
| | - Masayuki Yokode
- Department of Clinical Innovative Medicine, Translational Research Center, Kyoto University Hospital, Kyoto, 606-8507 Japan
| | - Hiroshi Kondoh
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507 Japan
- Geriatric Unit, Kyoto University Hospital, Kyoto, 606-8507 Japan
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Mérour JY, Buron F, Plé K, Bonnet P, Routier S. The azaindole framework in the design of kinase inhibitors. Molecules 2014; 19:19935-79. [PMID: 25460315 PMCID: PMC6271083 DOI: 10.3390/molecules191219935] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 11/10/2014] [Accepted: 11/18/2014] [Indexed: 01/05/2023] Open
Abstract
This review article illustrates the growing use of azaindole derivatives as kinase inhibitors and their contribution to drug discovery and innovation. The different protein kinases which have served as targets and the known molecules which have emerged from medicinal chemistry and Fragment-Based Drug Discovery (FBDD) programs are presented. The various synthetic routes used to access these compounds and the chemical pathways leading to their synthesis are also discussed. An analysis of their mode of binding based on X-ray crystallography data gives structural insights for the design of more potent and selective inhibitors.
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Affiliation(s)
- Jean-Yves Mérour
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans, UMR CNRS 7311, Orléans F-45067, France.
| | - Frédéric Buron
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans, UMR CNRS 7311, Orléans F-45067, France.
| | - Karen Plé
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans, UMR CNRS 7311, Orléans F-45067, France.
| | - Pascal Bonnet
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans, UMR CNRS 7311, Orléans F-45067, France.
| | - Sylvain Routier
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans, UMR CNRS 7311, Orléans F-45067, France.
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