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Thomas N, Schröder NH, Nowak MK, Wollnitzke P, Ghaderi S, von Wnuck Lipinski K, Wille A, Deister-Jonas J, Vogt J, Gräler MH, Dannenberg L, Buschmann T, Westhoff P, Polzin A, Kelm M, Keul P, Weske S, Levkau B. Sphingosine-1-phosphate suppresses GLUT activity through PP2A and counteracts hyperglycemia in diabetic red blood cells. Nat Commun 2023; 14:8329. [PMID: 38097610 PMCID: PMC10721873 DOI: 10.1038/s41467-023-44109-x] [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: 06/13/2022] [Accepted: 11/30/2023] [Indexed: 12/17/2023] Open
Abstract
Red blood cells (RBC) are the major carriers of sphingosine-1-phosphate (S1P) in blood. Here we show that variations in RBC S1P content achieved by altering S1P synthesis and transport by genetic and pharmacological means regulate glucose uptake and metabolic flux. This is due to S1P-mediated activation of the catalytic protein phosphatase 2 (PP2A) subunit leading to reduction of cell-surface glucose transporters (GLUTs). The mechanism dynamically responds to metabolic cues from the environment by increasing S1P synthesis, enhancing PP2A activity, reducing GLUT phosphorylation and localization, and diminishing glucose uptake in RBC from diabetic mice and humans. Functionally, it protects RBC against lipid peroxidation in hyperglycemia and diabetes by activating the pentose phosphate pathway. Proof of concept is provided by the resistance of mice lacking the S1P exporter MFSD2B to diabetes-induced HbA1c elevation and thiobarbituric acid reactive substances (TBARS) generation in diabetic RBC. This mechanism responds to pharmacological S1P analogues such as fingolimod and may be functional in other insulin-independent tissues making it a promising therapeutic target.
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Affiliation(s)
- Nadine Thomas
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Nathalie H Schröder
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Melissa K Nowak
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Philipp Wollnitzke
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Shahrooz Ghaderi
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | | | - Annalena Wille
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | | | - Jens Vogt
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Markus H Gräler
- Department of Anesthesiology and Intensive Care Medicine, Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
- Center for Molecular Biomedicine, Jena University Hospital, Jena, Germany
| | - Lisa Dannenberg
- Division of Cardiology, Pulmonology, and Vascular Medicine, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Tobias Buschmann
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Philipp Westhoff
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Düsseldorf, Germany
| | - Amin Polzin
- Division of Cardiology, Pulmonology, and Vascular Medicine, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Malte Kelm
- Division of Cardiology, Pulmonology, and Vascular Medicine, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Petra Keul
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Sarah Weske
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany
| | - Bodo Levkau
- Institute of Molecular Medicine III, Heinrich Heine University, Düsseldorf, Germany.
- CARID, Cardiovascular Research Institute Düsseldorf, Medical Faculty and University Hospital, Düsseldorf, Germany.
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2
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Alghanem L, Zhang X, Jaiswal R, Seyoum B, Mallisho A, Msallaty Z, Yi Z. Effect of Insulin and Pioglitazone on Protein Phosphatase 2A Interaction Partners in Primary Human Skeletal Muscle Cells Derived from Obese Insulin-Resistant Participants. ACS OMEGA 2022; 7:42763-42773. [PMID: 36467954 PMCID: PMC9713796 DOI: 10.1021/acsomega.2c04473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 11/01/2022] [Indexed: 05/16/2023]
Abstract
Skeletal muscle insulin resistance is a major contributor to type-2 diabetes (T2D). Pioglitazone is a potent insulin sensitizer of peripheral tissues by targeting peroxisome proliferator-activated receptor gamma. Pioglitazone has been reported to protect skeletal muscle cells from lipotoxicity by promoting fatty acid mobilization and insulin signaling. However, it is unclear whether pioglitazone increases insulin sensitivity through changes in protein-protein interactions involving protein phosphatase 2A (PP2A). PP2A regulates various cell signaling pathways such as insulin signaling. Interaction of the catalytic subunit of PP2A (PP2Ac) with protein partners is required for PP2A specificity and activity. Little is known about PP2Ac partners in primary human skeletal muscle cells derived from lean insulin-sensitive (Lean) and obese insulin-resistant (OIR) participants. We utilized a proteomics method to identify PP2Ac interaction partners in skeletal muscle cells derived from Lean and OIR participants, with or without insulin and pioglitazone treatments. In this study, 216 PP2Ac interaction partners were identified. Furthermore, 26 PP2Ac partners exhibited significant differences in their interaction with PP2Ac upon insulin treatments between the two groups. Multiple pathways and molecular functions are significantly enriched for these 26 interaction partners, such as nonsense-mediated decay, metabolism of RNA, RNA binding, and protein binding. Interestingly, pioglitazone restored some of these abnormalities. These results provide differential PP2Ac complexes in Lean and OIR in response to insulin/pioglitazone, which may help understand molecular mechanisms underpinning insulin resistance and the insulin-sensitizing effects of pioglitazone treatments, providing multiple targets in various pathways to reverse insulin resistance and prevent and/or manage T2D with less drug side effects.
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Affiliation(s)
- Lana Alghanem
- Department
of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan48201, United States
| | - Xiangmin Zhang
- Department
of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan48201, United States
| | - Ruchi Jaiswal
- Department
of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan48201, United States
| | - Berhane Seyoum
- Division
of Endocrinology, Wayne State University School of Medicine, Wayne State University, Detroit, Michigan48201, United States
| | - Abdullah Mallisho
- Division
of Endocrinology, Wayne State University School of Medicine, Wayne State University, Detroit, Michigan48201, United States
| | - Zaher Msallaty
- Division
of Endocrinology, Wayne State University School of Medicine, Wayne State University, Detroit, Michigan48201, United States
| | - Zhengping Yi
- Department
of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan48201, United States
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3
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Frendo-Cumbo S, Li T, Ammendolia DA, Coyaud E, Laurent EM, Liu Y, Bilan PJ, Polevoy G, Raught B, Brill JA, Klip A, Brumell JH. DCAF7 regulates cell proliferation through IRS1-FOXO1 signaling. iScience 2022; 25:105188. [PMID: 36248734 PMCID: PMC9556925 DOI: 10.1016/j.isci.2022.105188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 07/13/2022] [Accepted: 09/20/2022] [Indexed: 12/13/2022] Open
Abstract
Cell proliferation is dependent on growth factors insulin and IGF1. We sought to identify interactors of IRS1, the most proximal mediator of insulin/IGF1 signaling, that regulate cell proliferation. Using proximity-dependent biotin identification (BioID), we detected 40 proteins displaying proximal interactions with IRS1, including DCAF7 and its interacting partners DYRK1A and DYRK1B. In HepG2 cells, DCAF7 knockdown attenuated cell proliferation by inducing cell cycle arrest at G2. DCAF7 expression was required for insulin-stimulated AKT phosphorylation, and its absence promoted nuclear localization of the transcription factor FOXO1. DCAF7 knockdown induced expression of FOXO1-target genes implicated in G2 cell cycle inhibition, correlating with G2 cell cycle arrest. In Drosophila melanogaster, wing-specific knockdown of DCAF7/wap caused smaller wing size and lower wing cell number; the latter recovered upon double knockdown of wap and dfoxo. We propose that DCAF7 regulates cell proliferation and cell cycle via IRS1-FOXO1 signaling, of relevance to whole organism growth.
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Affiliation(s)
- Scott Frendo-Cumbo
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada,Department of Physiology, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Taoyingnan Li
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada,Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Dustin A. Ammendolia
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada,Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Etienne Coyaud
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
| | - Estelle M.N. Laurent
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
| | - Yuan Liu
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Philip J. Bilan
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Gordon Polevoy
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada,Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Julie A. Brill
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada,Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1L7, Canada,Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Amira Klip
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada,Department of Physiology, University of Toronto, Toronto, ON M5G 1L7, Canada,Department of Biochemistry, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - John H. Brumell
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada,Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1L7, Canada,Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada,SickKids IBD Centre, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada,Corresponding author
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4
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Yudhani RD, Nugrahaningsih DAA, Sholikhah EN, Mustofa M. The Molecular Mechanisms of Hypoglycemic Properties and Safety Profiles of Swietenia Macrophylla Seeds Extract: A Review. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.6972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2022] Open
Abstract
BACKGROUND: Insulin resistance (IR) is known as the root cause of type 2 diabetes; hence, it is a substantial therapeutic target. Nowadays, studies have shifted the focus to natural ingredients that have been utilized as a traditional diabetes treatment, including Swietenia macrophylla. Accumulating evidence supports the hypoglycemic activities of S. macrophylla seeds extract, although its molecular mechanisms have yet to be well-established.
AIM: This review focuses on the hypoglycemic molecular mechanisms of S. macrophylla seeds extract and its safety profiles.
METHODS: An extensive search of the latest literature was conducted from four main databases (PubMed, Scopus, Science Direct, and Google Scholar) using several keywords: “swietenia macrophylla, seeds, and diabetes;” “swietenia macrophylla, seeds, and oxidative stress;” “swietenia macrophylla, seeds, and inflammation;” “swietenia macrophylla, seeds, and GLUT4;” and “swietenia macrophylla, seeds, and toxicities.”
RESULTS: The hypoglycemic activities occur through modulating several pathways associated with IR and T2D pathogenesis. The seeds extract of S. macrophylla modulates oxidative stress by decreasing malondialdehyde (MDA), oxidized low-density lipoprotein, and thiobarbituric acid-reactive substances while increasing antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). Another propose mechanism is the modulating of the inflammatory pathway by attenuating nuclear factor kappa β, tumor necrosis factor α, inducible nitric oxide synthase, and cyclooxygenase 2. Some studies have shown that the extract can also control phosphatidylinositol-3-kinase/ Akt (PI3K/Akt) pathway by inducing glucose transporter 4, while suppressing phosphoenolpyruvate carboxykinase. Moreover, in vitro cytotoxicity and in vivo toxicity studies supported the safety profile of S. macrophylla seeds extract with the LD50 higher than 2000 mg/kg.
CONCLUSION: The potential of S. macrophylla seeds as antidiabetic candidate is supported by many studies that have documented their non-toxic and hypoglycemic effects, which involve several molecular pathways.
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Mustapha S, Mohammed M, Azemi AK, Yunusa I, Shehu A, Mustapha L, Wada Y, Ahmad MH, Ahmad WANW, Rasool AHG, Mokhtar SS. Potential Roles of Endoplasmic Reticulum Stress and Cellular Proteins Implicated in Diabesity. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:8830880. [PMID: 33995826 PMCID: PMC8099518 DOI: 10.1155/2021/8830880] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 03/28/2021] [Accepted: 04/05/2021] [Indexed: 12/12/2022]
Abstract
The role of the endoplasmic reticulum (ER) has evolved from protein synthesis, processing, and other secretory pathways to forming a foundation for lipid biosynthesis and other metabolic functions. Maintaining ER homeostasis is essential for normal cellular function and survival. An imbalance in the ER implied stressful conditions such as metabolic distress, which activates a protective process called unfolded protein response (UPR). This response is activated through some canonical branches of ER stress, i.e., the protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1α (IRE1α), and activating transcription factor 6 (ATF6). Therefore, chronic hyperglycemia, hyperinsulinemia, increased proinflammatory cytokines, and free fatty acids (FFAs) found in diabesity (a pathophysiological link between obesity and diabetes) could lead to ER stress. However, limited data exist regarding ER stress and its association with diabesity, particularly the implicated proteins and molecular mechanisms. Thus, this review highlights the role of ER stress in relation to some proteins involved in diabesity pathogenesis and provides insight into possible pathways that could serve as novel targets for therapeutic intervention.
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Affiliation(s)
- Sagir Mustapha
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
- Department of Pharmacology and Therapeutics, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Mustapha Mohammed
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Pulau Pinang, Malaysia
- Department of Clinical Pharmacy and Pharmacy Practice, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Ahmad Khusairi Azemi
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Ismaeel Yunusa
- Department of Clinical Pharmacy and Outcomes Sciences, University of South Carolina, College of Pharmacy, Columbia, SC, USA
| | - Aishatu Shehu
- Department of Pharmacology and Therapeutics, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Lukman Mustapha
- Department of Pharmaceutical and Medicinal Chemistry, Kaduna State University, Kaduna, Nigeria
| | - Yusuf Wada
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
- Department of Zoology, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Mubarak Hussaini Ahmad
- Department of Pharmacology and Therapeutics, Ahmadu Bello University Zaria, Kaduna, Nigeria
- School of Pharmacy Technician, Aminu Dabo College of Health Sciences and Technology, Kano, Nigeria
| | - Wan Amir Nizam Wan Ahmad
- Biomedicine Programme, School of Health Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Aida Hanum Ghulam Rasool
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
- Hospital Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Siti Safiah Mokhtar
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
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6
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Rehman K, Haider K, Jabeen K, Akash MSH. Current perspectives of oleic acid: Regulation of molecular pathways in mitochondrial and endothelial functioning against insulin resistance and diabetes. Rev Endocr Metab Disord 2020; 21:631-643. [PMID: 32125563 DOI: 10.1007/s11154-020-09549-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Insulin resistance (IR) and type 2 diabetes mellitus (T2DM) is a leading cause of deaths due to metabolic disorders in recent years. Molecular mechanisms involved in the initiation and development of IR and T2DM are multiples. The major factors include mitochondrial dysfunction which may cause incomplete fatty acid oxidation (FAO). Oleic acid upregulates the expression of genes causing FAO by deacetylation of PGC1α by PKA-dependent activation of SIRT1-PGC1α complex. Another potent factor for the development of IR and T2DM is endothelial dysfunction as damaged endothelium causes increased release of inflammatory mediators such as TNF-α, IL-6, IL-1β, sVCAM, sICAM, E-selectin and other proinflammatory cytokines. While, on the other hand, oleic acid has the ability to regulate E-selectin, and sICAM expression. Rest of the risk factors may include inflammation, β-cell dysfunction, oxidative stress, hormonal imbalance, apoptosis, and enzyme dysregulation. Here, we have highlighted how oleic acid regulates underlying causatives factors and hence, keeps surpassing effect in prevention and treatment of IR and T2DM. However, the percentage contribution of these factors in combating IR and ultimately averting T2DM is still debatable. Thus, because of its exceptional protective effect, it can be considered as an improved therapeutic agent in prophylaxis and/or treatment of IR and T2DM.
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Affiliation(s)
- Kanwal Rehman
- Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan.
| | - Kamran Haider
- Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan
| | - Komal Jabeen
- Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad, Pakistan
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7
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Biswas D, Dao KT, Mercer A, Cowie AM, Duffley L, El Hiani Y, Kienesberger PC, Pulinilkunnil T. Branched-chain ketoacid overload inhibits insulin action in the muscle. J Biol Chem 2020; 295:15597-15621. [PMID: 32878988 DOI: 10.1074/jbc.ra120.013121] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 08/29/2020] [Indexed: 12/18/2022] Open
Abstract
Branched-chain α-keto acids (BCKAs) are catabolites of branched-chain amino acids (BCAAs). Intracellular BCKAs are cleared by branched-chain ketoacid dehydrogenase (BCKDH), which is sensitive to inhibitory phosphorylation by BCKD kinase (BCKDK). Accumulation of BCKAs is an indicator of defective BCAA catabolism and has been correlated with glucose intolerance and cardiac dysfunction. However, it is unclear whether BCKAs directly alter insulin signaling and function in the skeletal and cardiac muscle cell. Furthermore, the role of excess fatty acids (FAs) in perturbing BCAA catabolism and BCKA availability merits investigation. By using immunoblotting and ultra-performance liquid chromatography MS/MS to analyze the hearts of fasted mice, we observed decreased BCAA-catabolizing enzyme expression and increased circulating BCKAs, but not BCAAs. In mice subjected to diet-induced obesity (DIO), we observed similar increases in circulating BCKAs with concomitant changes in BCAA-catabolizing enzyme expression only in the skeletal muscle. Effects of DIO were recapitulated by simulating lipotoxicity in skeletal muscle cells treated with saturated FA, palmitate. Exposure of muscle cells to high concentrations of BCKAs resulted in inhibition of insulin-induced AKT phosphorylation, decreased glucose uptake, and mitochondrial oxygen consumption. Altering intracellular clearance of BCKAs by genetic modulation of BCKDK and BCKDHA expression showed similar effects on AKT phosphorylation. BCKAs increased protein translation and mTORC1 activation. Pretreating cells with mTORC1 inhibitor rapamycin restored BCKA's effect on insulin-induced AKT phosphorylation. This study provides evidence for FA-mediated regulation of BCAA-catabolizing enzymes and BCKA content and highlights the biological role of BCKAs in regulating muscle insulin signaling and function.
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Affiliation(s)
- Dipsikha Biswas
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Khoi T Dao
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Angella Mercer
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Andrew M Cowie
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Luke Duffley
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Yassine El Hiani
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Petra C Kienesberger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Thomas Pulinilkunnil
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada.
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8
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Bi A, An W, Wang C, Hua Y, Fang F, Dong X, Chen R, Zhang Z, Luo L. SCR-1693 inhibits tau phosphorylation and improves insulin resistance associated cognitive deficits. Neuropharmacology 2020; 168:108027. [DOI: 10.1016/j.neuropharm.2020.108027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 02/27/2020] [Accepted: 03/01/2020] [Indexed: 12/29/2022]
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9
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Ma T, Cao N, Chen K, Wang H, Xu L, Xu C, Huang P. Microcystin-LR exposure disrupts the insulin signaling pathway in C2C12 mice muscle cell line. ENVIRONMENTAL TOXICOLOGY 2020; 35:194-202. [PMID: 31714646 DOI: 10.1002/tox.22856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/13/2019] [Accepted: 09/14/2019] [Indexed: 06/10/2023]
Abstract
Microcystin-LR (MC-LR) is a widely produced monocyclic heptapeptides in eutrophication waterbodies. MC-LR can induce various toxic effects in different cells. Our previous studies have found that MC-LR exposure can disrupt insulin signaling pathway in human liver cells (HL 7702). Skeletal muscle is one of the major organs for glucose disposal and responsive to insulin. However, the effects of MC-LR on insulin signaling pathway in muscle cells have not been fully explored. By using C2C12 mice muscle cells, this study aims to investigate the toxic effects of MC-LR in muscle cells with a focus on its effects on insulin signaling pathways. It was found that MC-LR entered into cells and inhibited protein phosphatase 2A (PP2A) significantly. Furthermore, MC-LR increased phosphorylation of Ser302, Ser307, Ser612 of insulin receptor substrate 1, AKT-Ser473, GSK3α-Ser21, and S6K1-Thr389 by inhibiting the activity of PP2A. The results in this study demonstrate that exposure of MCLR can disrupt the insulin pathway in muscle cells.
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Affiliation(s)
- Tianfeng Ma
- Department I of Clinical Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Naifang Cao
- Department I of Clinical Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Kele Chen
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Hao Wang
- Toxicology Program in the Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Lihong Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Chun Xu
- Department of Endocrinology, The Third Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Pu Huang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
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10
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Javadpour P, Dargahi L, Ahmadiani A, Ghasemi R. To be or not to be: PP2A as a dual player in CNS functions, its role in neurodegeneration, and its interaction with brain insulin signaling. Cell Mol Life Sci 2019; 76:2277-2297. [PMID: 30874837 PMCID: PMC11105459 DOI: 10.1007/s00018-019-03063-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 02/16/2019] [Accepted: 03/07/2019] [Indexed: 12/26/2022]
Abstract
Accumulating evidence has reached the consensus that the balance of phosphorylation state of signaling molecules is a pivotal point in the regulation of cell signaling. Therefore, characterizing elements (kinases-phosphatases) in the phosphorylation balance are at great importance. However, the role of phosphatase enzymes is less investigated than kinase enzymes. PP2A is a member of serine/threonine protein phosphatase that its imbalance has been reported in neurodegenerative diseases. Therefore, we reviewed the superfamily of phosphatases and more specifically PP2A, its regulation, and physiological functions participate in CNS. Thereafter, we discussed the latest findings about PP2A dysregulation in Alzheimer and Parkinson diseases and possible interplay between this phosphatase and insulin signaling pathways. Finally, activating/inhibitory modulators for PP2A activity as well as experimental methods for PP2A study have been reviewed.
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Affiliation(s)
- Pegah Javadpour
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Leila Dargahi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abolhassan Ahmadiani
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rasoul Ghasemi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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11
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Fan L, Liu MH, Guo M, Hu CX, Yan ZW, Chen J, Chen GQ, Huang Y. FAM122A, a new endogenous inhibitor of protein phosphatase 2A. Oncotarget 2018; 7:63887-63900. [PMID: 27588481 PMCID: PMC5325411 DOI: 10.18632/oncotarget.11698] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 08/24/2016] [Indexed: 01/19/2023] Open
Abstract
The regulation of the ubiquitously expressed protein phosphatase 2A (PP2A) is essential for various cellular functions such as cell proliferation, transformation, and fate determination. In this study, we demonstrate that the highly conserved protein in mammals, designated FAM122A, directly interacts with PP2A-Aα and B55α rather than B56α subunits, and inhibits the phosphatase activity of PP2A-Aα/B55α/Cα complex. Further, FAM122A potentiates the degradation of catalytic subunit PP2A-Cα with the increased poly-ubiquitination. In agreement, FAM122A silencing inhibits while its overexpression enhances cell growth and colony-forming ability. Collectively, we identify FAM122A as a new endogenous PP2A inhibitor and its physiological and pathophysiological significances warrant to be further investigated.
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Affiliation(s)
- Li Fan
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Man-Hua Liu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Meng Guo
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chuan-Xi Hu
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zhao-Wen Yan
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jing Chen
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Guo-Qiang Chen
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.,Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ying Huang
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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Wardhana DA, Ikeda K, Barinda AJ, Nugroho DB, Qurania KR, Yagi K, Miyata K, Oike Y, Hirata KI, Emoto N. Family with sequence similarity 13, member A modulates adipocyte insulin signaling and preserves systemic metabolic homeostasis. Proc Natl Acad Sci U S A 2018; 115:1529-1534. [PMID: 29386390 PMCID: PMC5816206 DOI: 10.1073/pnas.1720475115] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Adipose tissue dysfunction is causally implicated in the impaired metabolic homeostasis associated with obesity; however, detailed mechanisms underlying dysregulated adipocyte functions in obesity remain to be elucidated. Here we searched for genes that provide a previously unknown mechanism in adipocyte metabolic functions and identified family with sequence similarity 13, member A (Fam13a) as a factor that modifies insulin signal cascade in adipocytes. Fam13a was highly expressed in adipose tissue, predominantly in mature adipocytes, and its expression was substantially reduced in adipose tissues of obese compared with lean mice. We revealed that Fam13a accentuated insulin signaling by recruiting protein phosphatase 2A with insulin receptor substrate 1 (IRS1), leading to protection of IRS1 from proteasomal degradation. We further demonstrated that genetic loss of Fam13a exacerbated obesity-related metabolic disorders, while targeted activation of Fam13a in adipocytes ameliorated it in association with altered adipose tissue insulin sensitivity in mice. Our data unveiled a previously unknown mechanism in the regulation of adipocyte insulin signaling by Fam13a and identified its significant role in systemic metabolic homeostasis, shedding light on Fam13a as a pharmacotherapeutic target to treat obesity-related metabolic disorders.
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Affiliation(s)
- Donytra Arby Wardhana
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Higashinada, 658-8558 Kobe, Japan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo, 6500017 Kobe, Japan
| | - Koji Ikeda
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Higashinada, 658-8558 Kobe, Japan;
| | - Agian Jeffilano Barinda
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Higashinada, 658-8558 Kobe, Japan
| | - Dhite Bayu Nugroho
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Higashinada, 658-8558 Kobe, Japan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo, 6500017 Kobe, Japan
| | - Kikid Rucira Qurania
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Higashinada, 658-8558 Kobe, Japan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo, 6500017 Kobe, Japan
| | - Keiko Yagi
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Higashinada, 658-8558 Kobe, Japan
| | - Keishi Miyata
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, Chuo-ku, 860-8556 Kumamoto, Japan
- Department of Immunology, Allergy and Vascular Medicine, Graduate School of Medical Sciences, Kumamoto University, Chuo-ku, 860-8556 Kumamoto, Japan
| | - Yuichi Oike
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, Chuo-ku, 860-8556 Kumamoto, Japan
| | - Ken-Ichi Hirata
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo, 6500017 Kobe, Japan
| | - Noriaki Emoto
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Higashinada, 658-8558 Kobe, Japan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Chuo, 6500017 Kobe, Japan
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13
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Ramos E, Patiño P, Reiter RJ, Gil-Martín E, Marco-Contelles J, Parada E, de Los Rios C, Romero A, Egea J. Ischemic brain injury: New insights on the protective role of melatonin. Free Radic Biol Med 2017; 104:32-53. [PMID: 28065781 DOI: 10.1016/j.freeradbiomed.2017.01.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/20/2016] [Accepted: 01/04/2017] [Indexed: 12/15/2022]
Abstract
Stroke represents one of the most common causes of brain's vulnerability for many millions of people worldwide. The plethora of physiopathological events associated with brain ischemia are regulate through multiple signaling pathways leading to the activation of oxidative stress process, Ca2+ dyshomeostasis, mitochondrial dysfunction, proinflammatory mediators, excitotoxicity and/or programmed neuronal cell death. Understanding this cascade of molecular events is mandatory in order to develop new therapeutic strategies for stroke. In this review article, we have highlighted the pleiotropic effects of melatonin to counteract the multiple processes of the ischemic cascade. Additionally, experimental evidence supports its actions to ameliorate ischemic long-term behavioural and neuronal deficits, preserving the functional integrity of the blood-brain barrier, inducing neurogenesis and cell proliferation through receptor-dependent mechanism, as well as improving synaptic transmission. Consequently, the synthesis of melatonin derivatives designed as new multitarget-directed products has focused a great interest in this area. This latter has been reinforced by the low cost of melatonin and its reduced toxicity. Furthermore, its spectrum of usages seems to be wide and with the potential for improving human health. Nevertheless, the molecular and cellular mechanisms underlying melatonin´s actions need to be further exploration and accordingly, new clinical studies should be conducted in human patients with ischemic brain pathologies.
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Affiliation(s)
- Eva Ramos
- Department of Toxicology & Pharmacology, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain
| | - Paloma Patiño
- Paediatric Unit, La Paz University Hospital, Paseo de la Castellana 261, 28046 Madrid, Spain
| | - Russel J Reiter
- Department of Cellular and Structural Biology. University of Texas Health Science Center at San Antonio, USA
| | - Emilio Gil-Martín
- Department of Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Vigo, Spain
| | - José Marco-Contelles
- Medicinal Chemistry Laboratory, Institute of General Organic Chemistry (CSIC), Juan de la Cierva, 3, 28006 Madrid, Spain
| | - Esther Parada
- Instituto de Investigación Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain; Instituto de I+D del Medicamento Teófilo Hernando (ITH), Facultad de Medicina, Universidad Autónoma de Madrid, Spain
| | - Cristobal de Los Rios
- Instituto de Investigación Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain; Instituto de I+D del Medicamento Teófilo Hernando (ITH), Facultad de Medicina, Universidad Autónoma de Madrid, Spain
| | - Alejandro Romero
- Department of Toxicology & Pharmacology, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain.
| | - Javier Egea
- Instituto de Investigación Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain; Instituto de I+D del Medicamento Teófilo Hernando (ITH), Facultad de Medicina, Universidad Autónoma de Madrid, Spain.
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14
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Romero A, Ramos E, Patiño P, Oset-Gasque MJ, López-Muñoz F, Marco-Contelles J, Ayuso MI, Alcázar A. Melatonin and Nitrones As Potential Therapeutic Agents for Stroke. Front Aging Neurosci 2016; 8:281. [PMID: 27932976 PMCID: PMC5120103 DOI: 10.3389/fnagi.2016.00281] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/10/2016] [Indexed: 01/20/2023] Open
Abstract
Stroke is a disease of aging affecting millions of people worldwide, and recombinant tissue-type plasminogen activator (r-tPA) is the only treatment approved. However, r-tPA has a low therapeutic window and secondary effects which limit its beneficial outcome, urging thus the search for new more efficient therapies. Among them, neuroprotection based on melatonin or nitrones, as free radical traps, have arisen as drug candidates due to their strong antioxidant power. In this Perspective article, an update on the specific results of the melatonin and several new nitrones are presented.
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Affiliation(s)
- Alejandro Romero
- Department of Toxicology and Pharmacology, Faculty of Veterinary Medicine, Complutense University of Madrid Madrid, Spain
| | - Eva Ramos
- Department of Toxicology and Pharmacology, Faculty of Veterinary Medicine, Complutense University of Madrid Madrid, Spain
| | - Paloma Patiño
- Paediatric Unit, La Paz University Hospital Madrid, Spain
| | - Maria J Oset-Gasque
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Ciudad Universitaria Madrid, Spain
| | - Francisco López-Muñoz
- Faculty of Health, Camilo José Cela UniversityMadrid, Spain; Neuropsychopharmacology Unit, "Hospital 12 de Octubre" Research InstituteMadrid, Spain
| | - José Marco-Contelles
- Laboratory of Medicinal Chemistry, Institute of General Organic Chemistry (CSIC) Madrid, Spain
| | - María I Ayuso
- Neurovascular Research Group, Instituto de Biomedicina de Sevilla, Hospital Virgen del Rocío, Sevilla, Spain
| | - Alberto Alcázar
- Department of Investigation, IRYCIS, Hospital Ramón y Cajal, Madrid, Spain
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15
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Zhang X, Damacharla D, Ma D, Qi Y, Tagett R, Draghici S, Kowluru A, Yi Z. Quantitative proteomics reveals novel protein interaction partners of PP2A catalytic subunit in pancreatic β-cells. Mol Cell Endocrinol 2016; 424:1-11. [PMID: 26780722 PMCID: PMC4779412 DOI: 10.1016/j.mce.2016.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/15/2015] [Accepted: 01/07/2016] [Indexed: 12/19/2022]
Abstract
Protein phosphatase 2A (PP2A) is one of the major serine/threonine phosphatases. We hypothesize that PP2A regulates signaling cascades in pancreatic β-cells in the context of glucose-stimulated insulin secretion (GSIS). Using co-immunoprecipitation (co-IP) and tandem mass spectrometry, we globally identified the protein interaction partners of the PP2A catalytic subunit (PP2Ac) in insulin-secreting pancreatic β-cells. Among the 514 identified PP2Ac interaction partners, 476 were novel. This represents the first global view of PP2Ac protein-protein interactions caused by hyperglycemic conditions. Additionally, numerous PP2Ac partners were found involved in a variety of signaling pathways in the β-cell function, such as insulin secretion. Our data suggest that PP2A interacts with various signaling proteins necessary for physiological insulin secretion as well as signaling proteins known to regulate cell dysfunction and apoptosis in the pancreatic β-cells.
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Affiliation(s)
- Xiangmin Zhang
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Divyasri Damacharla
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Danjun Ma
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Yue Qi
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Rebecca Tagett
- Department of Computer Science, College of Engineering, Wayne State University, Detroit, MI, USA
| | - Sorin Draghici
- Department of Computer Science, College of Engineering, Wayne State University, Detroit, MI, USA
| | - Anjaneyulu Kowluru
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, 48201, USA; β-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, Detroit, MI, 48201, USA
| | - Zhengping Yi
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, 48201, USA.
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16
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Kumar S, Tikoo K. Independent role of PP2A and mTORc1 in palmitate induced podocyte death. Biochimie 2015; 112:73-84. [DOI: 10.1016/j.biochi.2015.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 02/13/2015] [Indexed: 11/26/2022]
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17
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Alpha-synuclein overexpression negatively regulates insulin receptor substrate 1 by activating mTORC1/S6K1 signaling. Int J Biochem Cell Biol 2015; 64:25-33. [PMID: 25813876 DOI: 10.1016/j.biocel.2015.03.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 02/26/2015] [Accepted: 03/09/2015] [Indexed: 12/15/2022]
Abstract
Alpha-synuclein (α-Syn) is a major component of Lewy bodies, a pathological feature of Parkinson's and other neurodegenerative diseases collectively known as synucleinopathies. Among the possible mechanisms of α-Syn-mediated neurotoxicity is interference with cytoprotective pathways such as insulin signaling. Insulin receptor substrate (IRS)-1 is a docking protein linking IRs to downstream signaling pathways such as phosphatidylinositol 3-kinase/Akt and mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase (S6K)1; the latter exerts negative feedback control on insulin signaling, which is impaired in Alzheimer's disease. Our previous study found that α-Syn overexpression can inhibit protein phosphatase (PP)2A activity, which is involved in the protective mechanism of insulin signaling. In this study, we found an increase in IRS-1 phosphorylation at Ser636 and decrease in tyrosine phosphorylation, which accelerated IRS-1 turnover and reduced insulin-Akt signaling in α-Syn-overexpressing SK-N-SH cells and transgenic mice. The mTOR complex (C)1/S6K1 blocker rapamycin inhibited the phosphorylation of IRS-1 at Ser636 in cells overexpressing α-Syn, suggesting that mTORC1/S6K1 activation by α-Syn causes feedback inhibition of insulin signaling via suppression of IRS-1 function. α-Syn overexpression also inhibited PP2A activity, while the PP2A agonist C2 ceramide suppressed both S6K1 activation and IRS-1 Ser636 phosphorylation upon α-Syn overexpression. Thus, α-Syn overexpression negatively regulated IRS-1 via mTORC1/S6K1 signaling while activation of PP2A reverses this process. These results provide evidence for a link between α-Syn and IRS-1 that may represent a novel mechanism for α-Syn-associated pathogenesis.
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18
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Caruso M, Ma D, Msallaty Z, Lewis M, Seyoum B, Al-janabi W, Diamond M, Abou-Samra AB, Højlund K, Tagett R, Draghici S, Zhang X, Horowitz JF, Yi Z. Increased interaction with insulin receptor substrate 1, a novel abnormality in insulin resistance and type 2 diabetes. Diabetes 2014; 63:1933-47. [PMID: 24584551 PMCID: PMC4030113 DOI: 10.2337/db13-1872] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Insulin receptor substrate 1 (IRS1) is a key mediator of insulin signal transduction. Perturbations involving IRS1 complexes may lead to the development of insulin resistance and type 2 diabetes (T2D). Surprisingly little is known about the proteins that interact with IRS1 in humans under health and disease conditions. We used a proteomic approach to assess IRS1 interaction partners in skeletal muscle from lean healthy control subjects (LCs), obese insulin-resistant nondiabetic control subjects (OCs), and participants with T2D before and after insulin infusion. We identified 113 novel endogenous IRS1 interaction partners, which represents the largest IRS1 interactome in humans and provides new targets for studies of IRS1 complexes in various diseases. Furthermore, we generated the first global picture of IRS1 interaction partners in LCs, and how they differ in OCs and T2D patients. Interestingly, dozens of proteins in OCs and/or T2D patients exhibited increased associations with IRS1 compared with LCs under the basal and/or insulin-stimulated conditions, revealing multiple new dysfunctional IRS1 pathways in OCs and T2D patients. This novel abnormality, increased interaction of multiple proteins with IRS1 in obesity and T2D in humans, provides new insights into the molecular mechanism of insulin resistance and identifies new targets for T2D drug development.
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Affiliation(s)
- Michael Caruso
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy/Health Sciences, Wayne State University, Detroit, MI
| | - Danjun Ma
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy/Health Sciences, Wayne State University, Detroit, MI
| | - Zaher Msallaty
- Division of Endocrinology, Wayne State University School of Medicine, Wayne State University, Detroit, MI
| | - Monique Lewis
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy/Health Sciences, Wayne State University, Detroit, MI
| | - Berhane Seyoum
- Division of Endocrinology, Wayne State University School of Medicine, Wayne State University, Detroit, MI
| | - Wissam Al-janabi
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy/Health Sciences, Wayne State University, Detroit, MI
| | - Michael Diamond
- Department of Obstetrics and Gynecology, Wayne State University, Detroit, MIDepartment of Obstetrics and Gynecology, Georgia Regents University, Augusta, GA
| | - Abdul B Abou-Samra
- Division of Endocrinology, Wayne State University School of Medicine, Wayne State University, Detroit, MIDepartment of Medicine, Hamad Medical Corporation, Doha, Qatar
| | - Kurt Højlund
- Diabetes Research Centre, Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Rebecca Tagett
- Department of Computer Science, College of Engineering, Wayne State University, Detroit, MI
| | - Sorin Draghici
- Department of Computer Science, College of Engineering, Wayne State University, Detroit, MI
| | - Xiangmin Zhang
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy/Health Sciences, Wayne State University, Detroit, MI
| | | | - Zhengping Yi
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy/Health Sciences, Wayne State University, Detroit, MI
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19
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Hançer NJ, Qiu W, Cherella C, Li Y, Copps KD, White MF. Insulin and metabolic stress stimulate multisite serine/threonine phosphorylation of insulin receptor substrate 1 and inhibit tyrosine phosphorylation. J Biol Chem 2014; 289:12467-84. [PMID: 24652289 DOI: 10.1074/jbc.m114.554162] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
IRS1 and IRS2 are key substrates of the insulin receptor tyrosine kinase. Mass spectrometry reveals more than 50 phosphorylated IRS1 serine and threonine residues (Ser(P)/Thr(P) residues) in IRS1 from insulin-stimulated cells or human tissues. We investigated a subset of IRS1 Ser(P)/Thr(P) residues using a newly developed panel of 25 phospho-specific monoclonal antibodies (αpS/TmAb(Irs1)). CHO cells overexpressing the human insulin receptor and rat IRS1 were stimulated with insulin in the absence or presence of inhibitors of the PI3K → Akt → mechanistic target of rapamycin (mTOR) → S6 kinase or MEK pathways. Nearly all IRS1 Ser(P)/Thr(P) residues were stimulated by insulin and significantly suppressed by PI3K inhibition; fewer were suppressed by Akt or mTOR inhibition, and none were suppressed by MEK inhibition. Insulin-stimulated Irs1 tyrosine phosphorylation (Tyr(P)(Irs1)) was enhanced by inhibition of the PI3K → Akt → mTOR pathway and correlated with decreased Ser(P)-302(Irs1), Ser(P)-307(Irs1), Ser(P)-318(Irs1), Ser(P)-325(Irs1), and Ser(P)-346(Irs1). Metabolic stress modeled by anisomycin, thapsigargin, or tunicamycin increased many of the same Ser(P)/Thr(P) residues as insulin, some of which (Ser(P)-302(Irs1), Ser(P)-307(Irs1), and four others) correlated significantly with impaired insulin-stimulated Tyr(P)(Irs1). Thus, IRS1 Ser(P)/Thr(P) is an integrated response to insulin stimulation and metabolic stress, which associates with reduced Tyr(P)(Irs1) in CHO(IR)/IRS1 cells.
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Affiliation(s)
- Nancy J Hançer
- From the Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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20
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Aye ILMH, Gao X, Weintraub ST, Jansson T, Powell TL. Adiponectin inhibits insulin function in primary trophoblasts by PPARα-mediated ceramide synthesis. Mol Endocrinol 2014; 28:512-24. [PMID: 24606127 DOI: 10.1210/me.2013-1401] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Maternal adiponectin (ADN) levels are inversely correlated with birth weight, and ADN infusion in pregnant mice down-regulates placental nutrient transporters and decreases fetal growth. In contrast to the insulin-sensitizing effects in adipose tissue and muscle, ADN inhibits insulin signaling in the placenta. However, the molecular mechanisms involved are unknown. We hypothesized that ADN inhibits insulin signaling and insulin-stimulated amino acid transport in primary human trophoblasts by peroxisome proliferator-activated receptor-α (PPARα)-mediated ceramide synthesis. Primary human term trophoblast cells were treated with ADN and/or insulin. ADN increased the phosphorylation of p38 MAPK and PPARα. ADN inhibited insulin signaling and insulin-stimulated amino acid transport. This effect was dependent on PPARα, because activation of PPARα with an agonist (GW7647) inhibited insulin signaling and function, whereas PPARα-small interfering RNA reversed the effects of ADN on the insulin response. ADN increased ceramide synthase expression and stimulated ceramide production. C2-ceramide inhibited insulin signaling and function, whereas inhibition of ceramide synthase (with Fumonisin B1) reversed the effects of ADN on insulin signaling and amino acid transport. These findings are consistent with the model that maternal ADN limits fetal growth mediated by activation of placental PPARα and ceramide synthesis, which inhibits placental insulin signaling and amino acid transport, resulting in reduced fetal nutrient availability.
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Affiliation(s)
- Irving L M H Aye
- Center for Pregnancy and Newborn Research (I.L.M.H.A., T.J., T.L.P.), Department of Obstetrics and Gynecology, and Department of Biochemistry (X.G., S.T.W.), University of Texas Health Science Center San Antonio, Texas 78229
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