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Heckmann M, Klanert G, Sandner G, Lanzerstorfer P, Auer M, Weghuber J. Fluorescence Microscopy-Based Quantitation of GLUT4 Translocation. Methods Appl Fluoresc 2022; 10. [PMID: 35008072 DOI: 10.1088/2050-6120/ac4998] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/10/2022] [Indexed: 11/11/2022]
Abstract
Postprandial insulin-stimulated glucose uptake into target tissue is crucial for the maintenance of normal blood glucose homeostasis. This step is rate-limited by the number of facilitative glucose transporters type 4 (GLUT4) present in the plasma membrane. Since insulin resistance and impaired GLUT4 translocation are associated with the development of metabolic disorders such as type 2 diabetes, this transporter has become an important target of antidiabetic drug research. The application of screening approaches that are based on the analysis of GLUT4 translocation to the plasma membrane to identify substances with insulinomimetic properties has gained global research interest in recent years. Here, we review methods that have been implemented to quantitate the translocation of GLUT4 to the plasma membrane. These methods can be broadly divided into two sections: microscopy-based technologies (e.g., immunoelectron, confocal or total internal reflection fluorescence microscopy) and biochemical and spectrometric approaches (e.g., membrane fractionation, photoaffinity labeling or flow cytometry). In this review, we discuss the most relevant approaches applied to GLUT4 thus far, highlighting the advantages and disadvantages of these approaches, and we provide a critical discussion and outlook into new methodological opportunities.
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Affiliation(s)
- Mara Heckmann
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
| | - Gerald Klanert
- FFoQSI GmbH-Austrian Competence Centre for Feed and Food Quality, Safety and Innovation, Technopark 1C, Tulln, 3430, AUSTRIA
| | - Georg Sandner
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
| | - Peter Lanzerstorfer
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
| | - Manfred Auer
- Division of Pathway Medicine, University of Edinburgh, University of Edinburgh Medical School, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, Edinburgh, EH8 9AB, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Julian Weghuber
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
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Imai M, Kawakami F, Kubo M, Kanzaki M, Maruyama H, Kawashima R, Maekawa T, Kurosaki Y, Kojima F, Ichikawa T. LRRK2 Inhibition Ameliorates Dexamethasone-Induced Glucose Intolerance via Prevents Impairment in GLUT4 Membrane Translocation in Adipocytes. Biol Pharm Bull 2021; 43:1660-1668. [PMID: 33132310 DOI: 10.1248/bpb.b20-00377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are associated with Parkinson's disease. LRRK2 is a large protein with multiple functional domains, including a guanosine 5'-triphosphate (GTP)-binding domain and a protein kinase domain. Recent studies indicated that the members of the Rab GTPase family, Rab8a and Rab10, which are involved in the membrane transport of the glucose transporter type 4 (GLUT4) during insulin-dependent glucose uptake, are phosphorylated by LRRK2. However, the physiological role of LRRK2 in the regulation of glucose metabolism is largely unknown. In the present study, we investigated the role of LRRK2 using dexamethasone (DEX)-induced glucose intolerance in mice. LRRK2 knockout (KO) mice exhibited suppressed glucose intolerance, even after treatment with DEX. The phosphorylation of LRRK2, Rab8a and Rab10 was increased in the adipose tissues of DEX-treated wild-type mice. In addition, inhibition of the LRRK2 kinase activity prevented the DEX-induced inhibition of GLUT4 membrane translocation and glucose uptake in cultured 3T3-L1 adipocytes. These results suggest that LRRK2 plays an important role in glucose metabolism in adipose tissues.
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Affiliation(s)
- Motoki Imai
- Department of Regulation Biochemistry, Graduate School of Medical Sciences, Kitasato University
| | - Fumitaka Kawakami
- Department of Regulation Biochemistry, Graduate School of Medical Sciences, Kitasato University.,Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science
| | - Makoto Kubo
- Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science.,Division of Clinical Immunology, Graduate School of Medical Sciences, Kitasato University
| | - Makoto Kanzaki
- Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University
| | - Hiroko Maruyama
- Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science.,Department of Cytopathology, Graduate School of Medical Sciences, Kitasato University
| | - Rei Kawashima
- Department of Regulation Biochemistry, Graduate School of Medical Sciences, Kitasato University.,Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science
| | - Tatsunori Maekawa
- Department of Regulation Biochemistry, Graduate School of Medical Sciences, Kitasato University.,Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science
| | - Yoshifumi Kurosaki
- Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science.,Department of Medical Laboratory Sciences, Kitasato University School of Allied Health Sciences
| | - Fumiaki Kojima
- Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science.,Department of Pharmacology, Kitasato University School of Allied Health Sciences
| | - Takafumi Ichikawa
- Department of Regulation Biochemistry, Graduate School of Medical Sciences, Kitasato University.,Research Facility of Regenerative Medicine and Cell Design, Kitasato University School of Allied Health Science
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Griesel BA, Matsuzaki S, Batushansky A, Griffin TM, Humphries KM, Olson AL. PFKFB3-dependent glucose metabolism regulates 3T3-L1 adipocyte development. FASEB J 2021; 35:e21728. [PMID: 34110658 PMCID: PMC8205188 DOI: 10.1096/fj.202100381rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/08/2021] [Accepted: 05/25/2021] [Indexed: 11/11/2022]
Abstract
Proliferation and differentiation of preadipocytes, and other cell types, is accompanied by an increase in glucose uptake. Previous work showed that a pulse of high glucose was required during the first 3 days of differentiation in vitro, but was not required after that. The specific glucose metabolism pathways required for adipocyte differentiation are unknown. Herein, we used 3T3-L1 adipocytes as a model system to study glucose metabolism and expansion of the adipocyte metabolome during the first 3 days of differentiation. Our primary outcome measures were GLUT4 and adiponectin, key proteins associated with healthy adipocytes. Using complete media with 0 or 5 mM glucose, we distinguished between developmental features that were dependent on the differentiation cocktail of dexamethasone, insulin, and isobutylmethylxanthine alone or the cocktail plus glucose. Cocktail alone was sufficient to activate the capacity for 2-deoxglucose uptake and glycolysis, but was unable to support the expression of GLUT4 and adiponectin in mature adipocytes. In contrast, 5 mM glucose in the media promoted a transient increase in glucose uptake and glycolysis as well as a significant expansion of the adipocyte metabolome and proteome. Using genetic and pharmacologic approaches, we found that the positive effects of 5 mM glucose on adipocyte differentiation were specifically due to increased expression of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a key regulator of glycolysis and the ancillary glucose metabolic pathways. Our data reveal a critical role for PFKFB3 activity in regulating the cellular metabolic remodeling required for adipocyte differentiation and maturation.
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Affiliation(s)
- Beth A Griesel
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | | | | | - Timothy M Griffin
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Kenneth M Humphries
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Ann Louise Olson
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Wang J, Huang M, Yang J, Ma X, Zheng S, Deng S, Huang Y, Yang X, Zhao P. Anti-diabetic activity of stigmasterol from soybean oil by targeting the GLUT4 glucose transporter. Food Nutr Res 2017; 61:1364117. [PMID: 28970778 PMCID: PMC5614214 DOI: 10.1080/16546628.2017.1364117] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/29/2017] [Indexed: 02/07/2023] Open
Abstract
The present study investigated the anti-diabetic activity and potential mechanism of stigmasterol (SMR), which is a kind of phytosterols derived from the edible soybean oil in vitro and in vivo. SMR displayed a mild GLUT4 translocation activity by 1.44-fold in L6 cells. L6 cells were treated with different concentration of SMR, showing significant effects on the enhancing glucose uptake. SMR administrated orally to the KK-Ay mice significantly alleviated their insulin resistance and oral glucose tolerance with reducing fasting blood-glucose levels and blood lipid indexes such as triglyceride and cholesterol. Moreover, the GLUT4 expression in L6 cells, skeletal muscle and white adipose tissue had been also enhanced. In this paper we conclude that, stigmasterol seems to have potential beneficial effects on the treatment of type 2 diabetes mellitus with the probable mechanism of targeting GLUT4 glucose transporter included increasing GLUT4 translocation and expression.
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Affiliation(s)
- Jialin Wang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Mi Huang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Jie Yang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Xinhua Ma
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Sijian Zheng
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Shihao Deng
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Yun Huang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Xinzhou Yang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China.,National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan, China
| | - Ping Zhao
- College of Life Sciences, South-Central University for Nationalities, Wuhan, China
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Schnuck JK, Sunderland KL, Kuennen MR, Vaughan RA. Characterization of the metabolic effect of β-alanine on markers of oxidative metabolism and mitochondrial biogenesis in skeletal muscle. J Exerc Nutrition Biochem 2016; 20:34-41. [PMID: 27508152 PMCID: PMC4977905 DOI: 10.20463/jenb.2016.06.20.2.5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/06/2016] [Accepted: 04/18/2016] [Indexed: 12/28/2022] Open
Abstract
[Purpose] β-alanine is a common component of numerous sports supplements purported to improve athletic performance through enhanced carnosine biosynthesis and related intracellular buffering. To date, the effects of β-alanine on oxidative metabolism remain largely unexplored. This work investigated the effects of β-alanine on the expression of proteins which regulate cellular energetics. [Methods] C2C12 myocytes were cultured and differentiated under standard conditions followed by treatment with either β-alanine or isonitrogenous non-metabolizable control D-alanine at 800μM for 24 hours. Metabolic gene and protein expression were quantified by qRT-PCR and immunoblotting, respectively. Glucose uptake and oxygen consumption were measured via fluorescence using commercially available kits. [Results] β-alanine-treated myotubes displayed significantly elevated markers of improved oxidative metabolism including elevated peroxisome proliferator-activated receptor β/δ (PPARβ/δ) and mitochondrial transcription factor a (TFAM) which led to increased mitochondrial content (evidenced by concurrent increases in cytochrome c content). Additionally, β-alanine-treated cells exhibited significantly increased oxygen consumption compared to control in a PPARβ/δ-dependent manner. β-alanine significantly enhanced expression of myocyte enhancer factor 2 (MEF-2) leading to increased glucose transporter 4 (GLUT4) content. [Conclusion] β-alanine appears to increase cellular oxygen consumption as well as the expression of several cellular proteins associated with improved oxidative metabolism, suggesting β-alanine supplementation may provide additional metabolic benefit (although these observations require in vivo experimental verification).
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Affiliation(s)
- Jamie K Schnuck
- Department of Exercise Science, High Point University, High Point North Carolina U.S.A
| | - Kyle L Sunderland
- Department of Exercise Science, High Point University, High Point North Carolina U.S.A
| | - Matthew R Kuennen
- Department of Exercise Science, High Point University, High Point North Carolina U.S.A
| | - Roger A Vaughan
- Department of Exercise Science, High Point University, High Point North Carolina U.S.A
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Kajno E, McGraw TE, Gonzalez E. Development of a new model system to dissect isoform specific Akt signalling in adipocytes. Biochem J 2015; 468:425-34. [PMID: 25856301 DOI: 10.1042/BJ20150191] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/09/2015] [Indexed: 12/17/2022]
Abstract
Our study describes the development and validation of a new model system that allows for acute control of signalling by specific Akt isoforms. This model system revealed new insights into the role of Akt kinases in glucose transport and adipogenesis. Protein kinase B (Akt) kinases are critical signal transducers mediating insulin action. Genetic studies revealed that Akt1 and Akt2 signalling differentially contribute to sustain lipid and glucose homoeostasis; however Akt isoform-specific effectors remain elusive due to the lack of a suitable model system to mechanistically interrogate Akt isoform-specific signalling. To overcome those technical limitations we developed a novel model system that provides acute and specific control of signalling by Akt isoforms. We generated mutants of Akt1 and Akt2 resistant to the allosteric Akt inhibitor MK-2206. We then developed adipocyte cell lines, in which endogenous Akt1 or Akt2 has been replaced by their corresponding drug-resistant Akt mutant. Treatment of those cells with MK-2206 allowed for acute and specific control of either Akt1 or Akt2 function. Our data showed that Akt1W80A and Akt2W80A mutants are resistant to MK-2206, dynamically regulated by insulin and able to signal to Akt downstream effectors. Analyses of insulin action in this cellular system showed that Akt1 and Akt2 are both able to mediate insulin regulation of the transcription factor forkhead box O1 (FoxO1) and the glucose transporter 4 (GLUT4), revealing a redundant role for these Akt kinases in the control of glucose transport into fat cells. In contrast, Akt1 signalling is uniquely required for adipogenesis, by controlling the mitotic clonal expansion (MCE) of pre-adipocytes that precedes white adipose cell differentiation. Our data provide new insights into the role of Akt kinases in glucose transport and adipogenesis and support our model system as a valuable tool for the biochemical characterization of signalling by specific Akt isoforms.
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