1
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Griffiths G, Brügger B, Freund C. Lipid switches in the immunological synapse. J Biol Chem 2024; 300:107428. [PMID: 38823638 PMCID: PMC11259711 DOI: 10.1016/j.jbc.2024.107428] [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: 11/14/2023] [Revised: 05/07/2024] [Accepted: 05/26/2024] [Indexed: 06/03/2024] Open
Abstract
Adaptive immune responses comprise the activation of T cells by peptide antigens that are presented by proteins of the Major Histocompatibility Complex (MHC) on the surface of an antigen-presenting cell. As a consequence of the T cell receptor interacting productively with a certain peptide-MHC complex, a specialized cell-cell junction known as the immunological synapse forms and is accompanied by changes in the spatiotemporal patterning and function of intracellular signaling molecules. Key modifications occurring at the cytoplasmic leaflet of the plasma and internal membranes in activated T cells comprise lipid switches that affect the binding and distribution of proteins within or near the lipid bilayer. Here, we describe two major classes of lipid switches that act at this critical water/membrane interface. Phosphoinositides are derived from phosphatidylinositol, an amphiphilic molecule that contains two fatty acid chains and a phosphate group that bridges the glycerol backbone to the carbohydrate inositol. The inositol ring can be variably (de-)phosphorylated by dedicated kinases and phosphatases, thereby creating phosphoinositide signatures that define the composition and properties of signaling molecules, molecular complexes, or whole organelles. Palmitoylation refers to the reversible attachment of the fatty acid palmitate to a substrate protein's cysteine residue. DHHC enzymes, named after the four conserved amino acids in their active site, catalyze this post-translational modification and thereby change the distribution of proteins at, between, and within membranes. T cells utilize these two types of molecular switches to adjust their properties to an activation process that requires changes in motility, transport, secretion, and gene expression.
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Affiliation(s)
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Institute of Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany.
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2
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Rimola V, Osthues T, Königs V, Geißlinger G, Sisignano M. Oxaliplatin Causes Transient Changes in TRPM8 Channel Activity. Int J Mol Sci 2021; 22:4962. [PMID: 34066977 PMCID: PMC8125753 DOI: 10.3390/ijms22094962] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 02/08/2023] Open
Abstract
Oxaliplatin is a third-generation platinum-based anticancer drug that is widely used as first-line treatment for colorectal carcinoma. Patients treated with oxaliplatin develop an acute peripheral pain several hours after treatment, mostly characterized by cold allodynia as well as a long-term chronic neuropathy. These two phenomena seem to be causally connected. However, the underlying mechanisms that trigger the acute peripheral pain are still poorly understood. Here we show that the activity of the transient receptor potential melastatin 8 (TRPM8) channel but not the activity of any other member of the TRP channel family is transiently increased 1 h after oxaliplatin treatment and decreased 24 h after oxaliplatin treatment. Mechanistically, this is connected with activation of the phospholipase C (PLC) pathway and depletion of phosphatidylinositol 4,5-bisphosphate (PIP2) after oxaliplatin treatment. Inhibition of the PLC pathway can reverse the decreased TRPM8 activity as well as the decreased PIP2-concentrations after oxaliplatin treatment. In summary, these results point out transient changes in TRPM8 activity early after oxaliplatin treatment and a later occurring TRPM8 channel desensitization in primary sensory neurons. These mechanisms may explain the transient cold allodynia after oxaliplatin treatment and highlight an important role of TRPM8 in oxaliplatin-induced acute and neuropathic pain.
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Affiliation(s)
- Vittoria Rimola
- Institute of Clinical Pharmacology, Pharmazentrum Frankfurt/ZAFES, University Hospital, Goethe-University, 60590 Frankfurt am Main, Germany; (V.R.); (G.G.)
| | - Tabea Osthues
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (T.O.); (V.K.)
| | - Vanessa Königs
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (T.O.); (V.K.)
| | - Gerd Geißlinger
- Institute of Clinical Pharmacology, Pharmazentrum Frankfurt/ZAFES, University Hospital, Goethe-University, 60590 Frankfurt am Main, Germany; (V.R.); (G.G.)
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (T.O.); (V.K.)
| | - Marco Sisignano
- Institute of Clinical Pharmacology, Pharmazentrum Frankfurt/ZAFES, University Hospital, Goethe-University, 60590 Frankfurt am Main, Germany; (V.R.); (G.G.)
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (T.O.); (V.K.)
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3
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Mazloumi Gavgani F, Karlsson T, Tangen IL, Morovicz AP, Arnesen VS, Turcu DC, Ninzima S, Spang K, Krakstad C, Guillermet-Guibert J, Lewis AE. Nuclear upregulation of class I phosphoinositide 3-kinase p110β correlates with high 47S rRNA levels in cancer cells. J Cell Sci 2021; 134:jcs.246090. [PMID: 33536247 DOI: 10.1242/jcs.246090] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 12/24/2020] [Indexed: 12/12/2022] Open
Abstract
The class I phosphoinositide 3-kinase (PI3K) catalytic subunits p110α and p110β are ubiquitously expressed but differently targeted in tumours. In cancer, PIK3CB (encoding p110β) is seldom mutated compared with PIK3CA (encoding p110α) but can contribute to tumorigenesis in certain PTEN-deficient tumours. The underlying molecular mechanisms are, however, unclear. We have previously reported that p110β is highly expressed in endometrial cancer (EC) cell lines and at the mRNA level in primary patient tumours. Here, we show that p110β protein levels are high in both the cytoplasmic and nuclear compartments in EC cells. Moreover, high nuclear:cytoplasmic staining ratios were detected in high-grade primary tumours. High levels of phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P 3] were measured in the nucleus of EC cells, and pharmacological and genetic approaches showed that its production was partly dependent upon p110β activity. Using immunofluorescence staining, p110β and PtdIns(3,4,5)P 3 were localised in the nucleolus, which correlated with high levels of 47S pre-rRNA. p110β inhibition led to a decrease in both 47S rRNA levels and cell proliferation. In conclusion, these results present a nucleolar role for p110β that may contribute to tumorigenesis in EC.This article has an associated First Person interview with Fatemeh Mazloumi Gavgani, joint first author of the paper.
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Affiliation(s)
| | - Thomas Karlsson
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Ingvild L Tangen
- Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen, Bergen 5021, Norway.,Department of Gynaecology and Obstetrics, Haukeland University Hospital, Bergen 5021, Norway
| | | | | | - Diana C Turcu
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Sandra Ninzima
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Katharina Spang
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Camilla Krakstad
- Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen, Bergen 5021, Norway.,Department of Gynaecology and Obstetrics, Haukeland University Hospital, Bergen 5021, Norway
| | - Julie Guillermet-Guibert
- Inserm U1037, Centre de Recherches en Cancérologie de Toulouse (CRCT), Institut National de la Santé et de la Recherche Médicale (INSERM), Université Toulouse III Paul Sabatier, 31037 Toulouse, France
| | - Aurélia E Lewis
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
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4
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Abstract
The field of phosphoinositide signaling has expanded significantly in recent years. Phosphoinositides (also known as phosphatidylinositol phosphates or PIPs) are universal signaling molecules that directly interact with membrane proteins or with cytosolic proteins containing domains that directly bind phosphoinositides and are recruited to cell membranes. Through the activities of phosphoinositide kinases and phosphoinositide phosphatases, seven distinct phosphoinositide lipid molecules are formed from the parent molecule, phosphatidylinositol. PIP signals regulate a wide range of cellular functions, including cytoskeletal assembly, membrane budding and fusion, ciliogenesis, vesicular transport, and signal transduction. Given the many excellent reviews on phosphoinositide kinases, phosphoinositide phosphatases, and PIPs in general, in this review, we discuss recent studies and advances in PIP lipid signaling in the retina. We specifically focus on PIP lipids from vertebrate (e.g., bovine, rat, mouse, toad, and zebrafish) and invertebrate (e.g., Drosophila, horseshoe crab, and squid) retinas. We also discuss the importance of PIPs revealed from animal models and human diseases, and methods to study PIP levels both in vitro and in vivo. We propose that future studies should investigate the function and mechanism of activation of PIP-modifying enzymes/phosphatases and further unravel PIP regulation and function in the different cell types of the retina.
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Affiliation(s)
- Raju V S Rajala
- Departments of Ophthalmology, Physiology, and Cell Biology, and Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104.
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5
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Lima BHF, Marques PE, Gomides LF, Mattos MS, Kraemer L, Queiroz-Junior CM, Lennon M, Hirsch E, Russo RC, Menezes GB, Hessel EM, Amour A, Teixeira MM. Converging TLR9 and PI3Kgamma signaling induces sterile inflammation and organ damage. Sci Rep 2019; 9:19085. [PMID: 31836766 PMCID: PMC6910931 DOI: 10.1038/s41598-019-55504-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 11/24/2019] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptor 9 (TLR9) and Phosphatidylinositol-3-kinase gamma (PI3Kγ) are very important effectors of the immune response, however, the importance of such crosstalk for disease development is still a matter of discussion. Here we show that PI3Kγ is required for immune responses in which TLR9 is a relevant trigger. We demonstrate the requirement of PI3Kγ for TLR9-induced inflammation in a model of CpG-induced pleurisy. Such requirement was further observed in inflammatory models where DNA sensing via TLR9 contributes to disease, such as silicosis and drug-induced liver injury. Using adoptive transfer, we demonstrate that PI3Kγ is important not only in leukocytes but also in parenchymal cells for the progression of inflammation. We demonstrate this crosstalk between TLR9 and PI3Kγ in vitro using human PBMCs. The inhibition of PI3Kγ in CpG-stimulated PBMCs resulted in reduction of both cytokine production and phosphorylated Akt. Therefore, drugs that target PI3Kγ have the potential to treat diseases mediated by excessive TLR9 signalling.
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Affiliation(s)
- Braulio Henrique Freire Lima
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Pedro Elias Marques
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Lindisley Ferreira Gomides
- Center for Gastrointestinal Biology, Instituto de Ciências Biológicas, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Matheus Silvério Mattos
- Physiology and Biophysics/Instituto de Ciencias Biologicas, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Lucas Kraemer
- Physiology and Biophysics/Instituto de Ciencias Biologicas, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Celso M Queiroz-Junior
- Departament of Morphology, Institute of Biological Sciences, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mark Lennon
- Target Sciences, GlaxoSmithKline, Stevenage, Hertfordshire, Stevenage, United Kingdom
| | - Emilio Hirsch
- Department ot Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | - Remo Castro Russo
- Physiology and Biophysics/Instituto de Ciencias Biologicas, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Gustavo Batista Menezes
- Center for Gastrointestinal Biology, Instituto de Ciências Biológicas, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Edith M Hessel
- Refractory Respiratory Inflammation DPU, GlaxoSmithKline, Hertfordshire, Stevenage, United Kingdom
| | - Augustin Amour
- Refractory Respiratory Inflammation DPU, GlaxoSmithKline, Hertfordshire, Stevenage, United Kingdom
| | - Mauro Martins Teixeira
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Feredal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
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6
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Regulation of HGF-induced hepatocyte proliferation by the small GTPase Arf6 through the PIP 2-producing enzyme PIP5K1A. Sci Rep 2017; 7:9438. [PMID: 28842595 PMCID: PMC5572707 DOI: 10.1038/s41598-017-09633-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/27/2017] [Indexed: 12/22/2022] Open
Abstract
HGF and its receptor c-Met are critical molecules in various biological processes. Others and we have previously shown that the small GTPase Arf6 plays a pivotal role in HGF signaling in hepatocytes. However, the molecular mechanism of how Arf6 regulates HGF signaling is unclear. Here, we show that Arf6 plays an important role in HGF-stimulated hepatocyte proliferation and liver regeneration through the phosphatidylinositol 4,5-bisphosphate (PIP2)-producing enzyme PIP5K1A. We find that knockdown of Arf6 and PIP5K1A in HepG2 cells inhibits HGF-stimulated proliferation, Akt activation, and generation of phosphatidylinositol 3,4,5-trisphosphate (PIP3) and its precursor PIP2. Interestingly, PIP5K1A is recruited to c-Met upon HGF stimulation in an Arf6 activity-dependent manner. Finally, we show that hepatocyte proliferation and liver regeneration after partial hepatectomy are suppressed in Pip5k1a knockout mice. These results provide insight into the molecular mechanism for HGF-stimulated hepatocyte proliferation and liver regeneration: Arf6 recruits PIP5K1A to c-Met and activates it upon HGF stimulation to produce PIP2 and subsequently PIP3, which in turn activates Akt to promote hepatocyte proliferation, thereby accelerating liver regeneration after liver injury.
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7
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Li SYT, Cheng STW, Zhang D, Leung PS. Identification and Functional Implications of Sodium/ Myo-Inositol Cotransporter 1 in Pancreatic β-Cells and Type 2 Diabetes. Diabetes 2017; 66:1258-1271. [PMID: 28202581 DOI: 10.2337/db16-0880] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 02/07/2017] [Indexed: 11/13/2022]
Abstract
Myo-inositol (MI), the precursor of the second messenger phosphoinositide (PI), mediates multiple cellular events. Rat islets exhibit active transport of MI, although the mechanism involved remains elusive. Here, we report, for the first time, the expression of sodium/myo-inositol cotransporter 1 (SMIT1) in rat islets and, specifically, β-cells. Genetic or pharmacological inhibition of SMIT1 impaired glucose-stimulated insulin secretion by INS-1E cells, probably via downregulation of PI signaling. In addition, SMIT1 expression in INS-1E cells and isolated islets was augmented by acute high-glucose exposure and reduced in chronic hyperglycemia conditions. In corroboration, chronic MI treatment improved the disease phenotypes of diabetic rats and islets. On the basis of our results, we postulate that the MI transporter SMIT1 is required to maintain a stable PI pool in β-cells in order that PI remains available despite its rapid turnover.
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Affiliation(s)
- Stephen Yu Ting Li
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Sam Tsz Wai Cheng
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Dan Zhang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Po Sing Leung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
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8
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Abstract
Lipids draw increasing attention of cell biologists because of the wide variety of functions beyond their role as building blocks of cellular membranes. Mitochondrial membranes possess characteristic lipid compositions that are intimately associated with mitochondrial architecture and activities. Therefore, quantitative assessment of lipids in isolated mitochondria is of importance for mitochondrial research. Here, I describe our workflow for quantitative analysis of glycerophospholipids in mitochondria with a focus on purification of pure mitochondrial fractions from yeast and cultured mammalian cells as well as improved settings for the analysis of cardiolipin by nano-electrospray ionization mass spectrometry.
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9
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Wang C, Palavicini JP, Wang M, Chen L, Yang K, Crawford PA, Han X. Comprehensive and Quantitative Analysis of Polyphosphoinositide Species by Shotgun Lipidomics Revealed Their Alterations in db/db Mouse Brain. Anal Chem 2016; 88:12137-12144. [DOI: 10.1021/acs.analchem.6b02947] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Chunyan Wang
- Center
for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Juan Pablo Palavicini
- Center
for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Miao Wang
- Center
for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Linyuan Chen
- Center
for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Kui Yang
- Division
of Bioorganic Chemistry and Molecular Pharmacology, Department of
Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Peter A. Crawford
- Center
for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Xianlin Han
- Center
for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
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10
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Abstract
Phosphatases play key roles in normal physiology and diseases. Studying phosphatases has been both essential and challenging, and the application of conventional genetic and biochemical methods has led to crucial but still limited understanding of their mechanisms, substrates, and exclusive functions within highly intricate networks. With the advances in technologies such as cellular imaging and molecular and chemical biology in terms of sensitive tools and methods, the phosphatase field has thrived in the past years and has set new insights for cell signaling studies and for therapeutic development. In this review, we give an overview of the existing interdisciplinary tools for phosphatases, give examples on how they have been applied to increase our understanding of these enzymes, and suggest how they-and other tools yet barely used in the phosphatase field-might be adapted to address future questions and challenges.
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Affiliation(s)
- Sara Fahs
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
| | - Pablo Lujan
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
| | - Maja Köhn
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
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11
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Kam TI, Park H, Gwon Y, Song S, Kim SH, Moon SW, Jo DG, Jung YK. FcγRIIb-SHIP2 axis links Aβ to tau pathology by disrupting phosphoinositide metabolism in Alzheimer's disease model. eLife 2016; 5. [PMID: 27834631 PMCID: PMC5106215 DOI: 10.7554/elife.18691] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 10/17/2016] [Indexed: 02/02/2023] Open
Abstract
Amyloid-β (Aβ)-containing extracellular plaques and hyperphosphorylated tau-loaded intracellular neurofibrillary tangles are neuropathological hallmarks of Alzheimer's disease (AD). Although Aβ exerts neuropathogenic activity through tau, the mechanistic link between Aβ and tau pathology remains unknown. Here, we showed that the FcγRIIb-SHIP2 axis is critical in Aβ1-42-induced tau pathology. Fcgr2b knockout or antagonistic FcγRIIb antibody inhibited Aβ1-42-induced tau hyperphosphorylation and rescued memory impairments in AD mouse models. FcγRIIb phosphorylation at Tyr273 was found in AD brains, in neuronal cells exposed to Aβ1-42, and recruited SHIP2 to form a protein complex. Consequently, treatment with Aβ1-42 increased PtdIns(3,4)P2 levels from PtdIns(3,4,5)P3 to mediate tau hyperphosphorylation. Further, we found that targeting SHIP2 expression by lentiviral siRNA in 3xTg-AD mice or pharmacological inhibition of SHIP2 potently rescued tau hyperphosphorylation and memory impairments. Thus, we concluded that the FcγRIIb-SHIP2 axis links Aβ neurotoxicity to tau pathology by dysregulating PtdIns(3,4)P2 metabolism, providing insight into therapeutic potential against AD.
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Affiliation(s)
- Tae-In Kam
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea.,Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Baltimore, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Hyejin Park
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea.,Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Baltimore, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Youngdae Gwon
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Sungmin Song
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Seo-Hyun Kim
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Seo Won Moon
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - Yong-Keun Jung
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul, Korea
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12
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Guenat S, Rouleau N, Bielmann C, Bedard J, Maurer F, Allaman-Pillet N, Nicod P, Bielefeld-Sévigny M, Beckmann JS, Bonny C, Bossé R, Roduit R. Homogeneous and Nonradioactive High-Throughput Screening Platform for the Characterization of Kinase Inhibitors in Cell Lysates. ACTA ACUST UNITED AC 2016; 11:1015-26. [PMID: 17092917 DOI: 10.1177/1087057106294697] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Protein kinases are directly implicated in many human diseases; therefore, kinase inhibitors show great promises as new therapeutic drugs. In an effort to facilitate the screening and the characterization of kinase inhibitors, a novel application of the AlphaScreen technology was developed to monitor JNK activity from (1) purified kinase preparations and (2) endogenous kinase from cell lysates preactivated with different cytokines. The authors confirmed that both adenosine triphosphate (ATP) competitive as well as peptide-based JNK inhibitors were able to block the activity of both recombinant and HepG2 endogenous JNK activity. Using the same luminescence technique adapted for binding studies, the authors characterized peptide inhibitor mechanisms by measuring the binding affinity of the inhibitors for JNK. Because of the versatility of the technology, this cell-based JNK kinase assay could be adapted to other kinases and would represent a powerful tool to evaluate endogenous kinase activity and test a large number of potential inhibitors in a more physiologically relevant environment.
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Affiliation(s)
- Sylvie Guenat
- Service of Medical Genetics, CHUV, Lausanne, Switzerland
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13
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Benjamin ER, Haftl SL, Xanthos DN, Crumley G, Hachicha M, Valenzano KJ. A Miniaturized Column Chromatography Method for Measuring Receptor-Mediated Inositol Phosphate Accumulation. ACTA ACUST UNITED AC 2016; 9:343-53. [PMID: 15191651 DOI: 10.1177/1087057103262841] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Inositol phosphates (IPs), such as 1,4,5-inositol-trisphosphate (IP3), comprise a ubiquitous intracellular signaling cascade initiated in response to G protein-coupled receptor-mediated activation of phospholipase C. Classical methods for measuring intracellular accumulation of these molecules include time-consuming high-performance liquid chromatography (HPLC) separation or large-volume, gravity-fed anion-exchange column chromatography. More recent approaches, such as radio-receptor and AlphaScreen™ assays, offer higher throughput. However, these techniques rely on measurement of IP3itself, rather than its accumulation with other downstream IPs, and often suffer from poor signal-to-noise ratios due to the transient nature of IP3. The authors have developed a miniaturized, anion-exchange chromatography method for measuring inositol phosphate accumulation in cells that takes advantage of signal amplification achieved through measuring IP3and downstream IPs. This assay uses centrifugation of 96-well-formatted anion-exchange mini-columns for the isolation of radiolabeled inositol phosphates from cell extracts, followed by low-background dry-scintillation counting. This improved assay method measures receptor-mediated IP accumulation with signal-to-noise and pharmacological values comparable to the classical large-volume, column-based methods. Assay validation data for recombinant muscarinic receptor 1, galanin receptor 2, and rat astrocyte metabotropic glutamate receptor 5 are presented. This miniaturized protocol reduces reagent usage and assay time as compared to large-column methods and is compatible with standard 96-well scintillation counters.
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MESH Headings
- Animals
- Astrocytes/metabolism
- Base Sequence
- CHO Cells
- Cell Line
- Chromatography, Ion Exchange/instrumentation
- Chromatography, Ion Exchange/methods
- Cricetinae
- DNA, Complementary/genetics
- Humans
- Inositol 1,4,5-Trisphosphate
- Inositol Phosphates/analysis
- Inositol Phosphates/metabolism
- Miniaturization/instrumentation
- Miniaturization/methods
- Rats
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Metabotropic Glutamate 5
- Receptor, Muscarinic M1/metabolism
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Metabotropic Glutamate/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Signal Transduction
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Affiliation(s)
- Elfrida R Benjamin
- Purdue Pharma Discovery Research, 6 Cedarbrook Drive, Cranbury, NJ 08512, USA.
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14
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Entamoeba histolytica Cysteine Proteinase 5 Evokes Mucin Exocytosis from Colonic Goblet Cells via αvβ3 Integrin. PLoS Pathog 2016; 12:e1005579. [PMID: 27073869 PMCID: PMC4830554 DOI: 10.1371/journal.ppat.1005579] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/27/2016] [Indexed: 12/11/2022] Open
Abstract
Critical to the pathogenesis of intestinal amebiasis, Entamoeba histolytica (Eh) induces mucus hypersecretion and degrades the colonic mucus layer at the site of invasion. The parasite component(s) responsible for hypersecretion are poorly defined, as are regulators of mucin secretion within the host. In this study, we have identified the key virulence factor in live Eh that elicits the fast release of mucin by goblets cells as cysteine protease 5 (EhCP5) whereas, modest mucus secretion occurred with secreted soluble EhCP5 and recombinant CP5. Coupling of EhCP5-αvβ3 integrin on goblet cells facilitated outside-in signaling by activating SRC family kinases (SFK) and focal adhesion kinase that resulted in the activation/phosphorlyation of PI3K at the site of Eh contact and production of PIP3. PKCδ was activated at the EhCP5-αvβ3 integrin contact site that specifically regulated mucin secretion though the trafficking vesicle marker myristoylated alanine-rich C-kinase substrate (MARCKS). This study has identified that EhCP5 coupling with goblet cell αvβ3 receptors can initiate a signal cascade involving PI3K, PKCδ and MARCKS to drive mucin secretion from goblet cells critical in disease pathogenesis. An interesting facet to the protozoan parasite Entamoeba histolytica is the ability to cause disease in a very limited subset of individuals, subject to first overcoming the intestinal mucus barrier within the gastrointestinal tract. Mucins, which are the primary constituent of the mucus layer are secreted basally to maintain the barrier and also in response to a variety of pathogens and noxious threats to protect the sensitive epithelium. Unfortunately, the mechanisms and signal cascades that regulate this secretion event are largely unknown. Here we describe how one such pathogen targets a specific host receptor on mucin-secreted cells to elicit secretion by activating distinct signaling pathways. Further, we have identified the parasite component responsible for this event. Our study provides insight in the pathogenesis of E. histolytica along laying the foundation for a broader understanding of how mucin secretion is regulated. We believe the pathways and mechanisms identified here can be applied to a wide-array of pathogens to understand how pathogens are kept away from the epithelium and how exploitation of this may lead to disease.
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15
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Mok HJ, Shin H, Lee JW, Lee GK, Suh CS, Kim KP, Lim HJ. Age-Associated Lipidome Changes in Metaphase II Mouse Oocytes. PLoS One 2016; 11:e0148577. [PMID: 26881843 PMCID: PMC4755615 DOI: 10.1371/journal.pone.0148577] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/19/2016] [Indexed: 11/18/2022] Open
Abstract
The quality of mammalian oocytes declines with age, which negatively affects fertilization and developmental potential. The aging process often accompanies damages to macromolecules such as proteins, DNA, and lipids. To investigate if aged oocytes display an altered lipidome compared to young oocytes, we performed a global lipidomic analysis between oocytes from 4-week-old and 42 to 50-week-old mice. Increased oxidative stress is often considered as one of the main causes of cellular aging. Thus, we set up a group of 4-week-old oocytes treated with hydrogen peroxide (H2O2), a commonly used oxidative stressor, to compare if similar lipid species are altered between aged and oxidative-stressed oocytes. Between young and aged oocytes, we identified 26 decreased and 6 increased lipids in aged oocytes; and between young and H2O2-treated oocytes, we identified 35 decreased and 26 increased lipids in H2O2-treated oocytes. The decreased lipid species in these two comparisons were overlapped, whereas the increased lipid species were distinct. Multiple phospholipid classes, phosphatidic acid (PA), phosphatidylinositol (PI), phosphatidylserine (PS), and lysophosphatidylserine (LPS) significantly decreased both in H2O2-treated and aged oocytes, suggesting that the integrity of plasma membrane is similarly affected under these conditions. In contrast, a dramatic increase in diacylglycerol (DG) was only noted in H2O2-treated oocytes, indicating that the acute effect of H2O2-caused oxidative stress is distinct from aging-associated lipidome alteration. In H2O2-treated oocytes, the expression of lysophosphatidylcholine acyltransferase 1 increased along with increases in phosphatidylcholine. Overall, our data reveal that several classes of phospholipids are affected in aged oocytes, suggesting that the integrity of plasma membrane is associated with maintaining fertilization and developmental potential of mouse oocytes.
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Affiliation(s)
- Hyuck Jun Mok
- Department of Applied Chemistry, The Institute of Natural Science, Kyung Hee University, Yongin, Gyeonggi-do, Korea
| | - Hyejin Shin
- Department of Biomedical Science & Technology, Institute of Biomedical Science & Technology, Konkuk University, Seoul, Korea
| | - Jae Won Lee
- Department of Applied Chemistry, The Institute of Natural Science, Kyung Hee University, Yongin, Gyeonggi-do, Korea
| | - Geun-Kyung Lee
- Department of Biomedical Science & Technology, Institute of Biomedical Science & Technology, Konkuk University, Seoul, Korea
| | - Chang Suk Suh
- Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Kwang Pyo Kim
- Department of Applied Chemistry, The Institute of Natural Science, Kyung Hee University, Yongin, Gyeonggi-do, Korea
- * E-mail: (PKP); (HJL)
| | - Hyunjung Jade Lim
- Department of Biomedical Science & Technology, Institute of Biomedical Science & Technology, Konkuk University, Seoul, Korea
- Department of Veterinary Medicine, Konkuk University, Seoul, Korea
- * E-mail: (PKP); (HJL)
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Evadé L, Dausse E, Taouji S, Daguerre E, Chevet E, Toulmé JJ. Aptamer-mediated nanoparticle interactions: from oligonucleotide-protein complexes to SELEX screens. Methods Mol Biol 2016; 1297:153-67. [PMID: 25896002 DOI: 10.1007/978-1-4939-2562-9_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Aptamers are oligonucleotides displaying specific binding properties for a predetermined target. They can be easily immobilized on various surfaces such as nanoparticles. Functionalized particles can then be used to various aims. We took advantage of the AlphaScreen(®) technology for monitoring aptamer-mediated interactions. A particle bearing an aptamer contains a photosensitizer whereas another type of particle contains a chemiluminescer. Irradiation causes the formation of singlet oxygen species in the photosensitizer-containing bead that in turn activates the chemiluminescer. Luminescence emission can be observed if the two types of beads are in close proximity (<200 nm). This is achieved when the cognate ligand of the aptamer is grafted onto the chemiluminescer-containing bead. Using this technology we have screened oligonucleotide libraries and monitored aptamer-protein interactions. This constitutes the basis for aptamer-based analytical assays.
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Affiliation(s)
- Laetitia Evadé
- Novaptech, European Institute of Chemistry and Biology, Pessac, France
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17
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The Effector Domain of MARCKS Is a Nuclear Localization Signal that Regulates Cellular PIP2 Levels and Nuclear PIP2 Localization. PLoS One 2015; 10:e0140870. [PMID: 26470026 PMCID: PMC4607481 DOI: 10.1371/journal.pone.0140870] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 10/01/2015] [Indexed: 01/01/2023] Open
Abstract
Translocation to the nucleus of diacylglycerol kinase (DGK)– ζ is dependent on a sequence homologous to the effector domain of Myristoylated Alanine Rich C-Kinase Substrate (MARCKS). These data would suggest that MARCKS could also localize to the nucleus. A single report demonstrated immunofluorescence staining of MARCKS in the nucleus; however, further experimental evidence confirming the specific domain responsible for this localization has not been reported. Here, we report that MARCKS is present in the nucleus in GBM cell lines. We then over-expressed wild-type MARCKS (WT) and MARCKS with the effector domain deleted (ΔED), both tagged with V5-epitope in a GBM cell line with low endogenous MARCKS expression (U87). We found that MARCKS-WT localized to the nucleus, while the MARCKS construct without the effector domain remained in the cytoplasm. We also found that over-expression of MARCKS-WT resulted in a significant increase in total cellular phosphatidyl-inositol (4,5) bisphosphate (PIP2) levels, consistent with prior evidence that MARCKS can regulate PIP2 levels. We also found increased staining for PIP2 in the nucleus with MARCKS-WT over-expression compared to MARCKS ΔED by immunofluorescence. Interestingly, we observed MARCKS and PIP2 co-localization in the nucleus. Lastly, we found changes in gene expression when MARCKS was not present in the nucleus (MARCKS ΔED). These data indicate that the MARCKS effector domain can function as a nuclear localization signal and that this sequence is critical for the ability of MARCKS to regulate PIP2 levels, nuclear localization, and gene expression. These data suggests a novel role for MARCKS in regulating nuclear functions such as gene expression.
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18
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Płóciennikowska A, Zdioruk MI, Traczyk G, Świątkowska A, Kwiatkowska K. LPS-induced clustering of CD14 triggers generation of PI(4,5)P2. J Cell Sci 2015; 128:4096-111. [PMID: 26446256 DOI: 10.1242/jcs.173104] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 09/30/2015] [Indexed: 01/08/2023] Open
Abstract
Bacterial lipopolysaccharide (LPS) induces strong pro-inflammatory reactions after sequential binding to CD14 protein and TLR4 receptor. Here, we show that CD14 controls generation of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] in response to LPS binding. In J774 cells and HEK293 cells expressing CD14 exposed to 10-100 ng/ml LPS, the level of PI(4,5)P2 rose in a biphasic manner with peaks at 5-10 min and 60 min. After 5-10 min of LPS stimulation, CD14 underwent prominent clustering in the plasma membrane, accompanied by accumulation of PI(4,5)P2 and type-I phosphatidylinositol 4-phosphate 5-kinase (PIP5K) isoforms Iα and Iγ (encoded by Pip5k1a and Pip5k1c, respectively) in the CD14 region. Clustering of CD14 with antibodies, without LPS and TLR4 participation, was sufficient to trigger PI(4,5)P2 elevation. The newly generated PI(4,5)P2 accumulated in rafts, which also accommodated CD14 and a large portion of PIP5K Iα and PIP5K Iγ. Silencing of PIP5K Iα and PIP5K Iγ, or application of drugs interfering with PI(4,5)P2 synthesis and availability, abolished the LPS-induced PI(4,5)P2 elevation and inhibited downstream pro-inflammatory reactions. Taken together, these data indicate that LPS induces clustering of CD14, which triggers PI(4,5)P2 generation in rafts that is required for maximal pro-inflammatory signaling of TLR4.
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Affiliation(s)
- Agnieszka Płóciennikowska
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Mykola I Zdioruk
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Gabriela Traczyk
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Anna Świątkowska
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
| | - Katarzyna Kwiatkowska
- Nencki Institute of Experimental Biology, Laboratory of Molecular Membrane Biology, 3 Pasteur St., Warsaw 02-093, Poland
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19
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Phosphoinositide dynamics in the postsynaptic membrane compartment: Mechanisms and experimental approach. Eur J Cell Biol 2015; 94:401-14. [DOI: 10.1016/j.ejcb.2015.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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20
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Assaying PTEN catalysis in vitro. Methods 2015; 77-78:51-7. [DOI: 10.1016/j.ymeth.2014.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/13/2014] [Accepted: 11/04/2014] [Indexed: 12/15/2022] Open
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21
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Lee HK, Chaboub LS, Zhu W, Zollinger D, Rasband MN, Fancy SPJ, Deneen B. Daam2-PIP5K is a regulatory pathway for Wnt signaling and therapeutic target for remyelination in the CNS. Neuron 2015; 85:1227-43. [PMID: 25754822 DOI: 10.1016/j.neuron.2015.02.024] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 11/17/2014] [Accepted: 02/10/2015] [Indexed: 01/27/2023]
Abstract
Wnt signaling plays an essential role in developmental and regenerative myelination of the CNS; however, contributions of proximal regulators of the Wnt receptor complex to these processes remain undefined. To identify components of the Wnt pathway that regulate these processes, we applied a multifaceted discovery platform and found that Daam2-PIP5K comprise a novel pathway regulating Wnt signaling and myelination. Using dorsal patterning of the chick spinal cord we found that Daam2 promotes Wnt signaling and receptor complex formation through PIP5K-PIP2. Analysis of Daam2 function in oligodendrocytes (OLs) revealed that it suppresses OL differentiation during development, after white matter injury (WMI), and is expressed in human white matter lesions. These findings suggest a pharmacological strategy to inhibit Daam2-PIP5K function, application of which stimulates remyelination after WMI. Put together, our studies integrate information from multiple systems to identify a novel regulatory pathway for Wnt signaling and potential therapeutic target for WMI.
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Affiliation(s)
- Hyun Kyoung Lee
- Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Lesley S Chaboub
- Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA; Program in Developmental Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Wenyi Zhu
- Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA; Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Daniel Zollinger
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Stephen P J Fancy
- Departments of Pediatrics and Neurology, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, California 94143, USA
| | - Benjamin Deneen
- Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA; Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA; Program in Developmental Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA; Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA; Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
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22
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Cai T, Shu Q, Hou J, Liu P, Niu L, Guo X, Liu CC, Yang F. Profiling and Relative Quantitation of Phosphoinositides by Multiple Precursor Ion Scanning Based on Phosphate Methylation and Isotopic Labeling. Anal Chem 2014; 87:513-21. [DOI: 10.1021/ac503224j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Tanxi Cai
- Laboratory of
Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingbo Shu
- Laboratory of
Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - JunJie Hou
- National
Laboratory
of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Peibin Liu
- Laboratory of
Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Lili Niu
- Laboratory of
Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaojing Guo
- Laboratory of
Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | | | - Fuquan Yang
- Laboratory of
Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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23
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Trovò L, Stroobants S, D'Hooge R, Ledesma MD, Dotti CG. Improvement of biochemical and behavioral defects in the Niemann-Pick type A mouse by intraventricular infusion of MARCKS. Neurobiol Dis 2014; 73:319-26. [PMID: 25251606 DOI: 10.1016/j.nbd.2014.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 07/31/2014] [Accepted: 09/12/2014] [Indexed: 12/28/2022] Open
Abstract
Niemann-Pick disease type A (NPDA) is a fatal disease due to mutations in the acid sphingomyelinase (ASM) gene, which triggers the abnormal accumulation of sphingomyelin (SM) in lysosomes and the plasma membrane of mutant cells. Although the disease affects multiple organs, the impact on the brain is the most invalidating feature. The mechanisms responsible for the cognitive deficit characteristic of this condition are only partially understood. Using mice lacking the ASM gene (ASMko), a model system in NPDA research, we report here that high sphingomyelin levels in mutant neurons lead to low synaptic levels of phosphoinositide PI(4,5)P2 and reduced activity of its hydrolyzing phosphatase PLCγ, which are key players in synaptic plasticity events. In addition, mutant neurons have reduced levels of membrane-bound MARCKS, a protein required for PI(4,5)P2 membrane clustering and hydrolysis. Intracerebroventricular infusion of a peptide that mimics the effector domain of MARCKS increases the content of PI(4,5)P2 in the synaptic membrane and ameliorates behavioral abnormalities in ASMko mice.
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Affiliation(s)
- Laura Trovò
- Center for Human Genetics, VIB Center for the Biology of Disease and Katholieke Universiteit Leuven, Herestraat 49, 3000 Leuven, Belgium.
| | - Stijn Stroobants
- Laboratory of Biological Psychology, Faculty of Psychology and Educational Sciences, University of Leuven (K.U. Leuven), Belgium
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, Faculty of Psychology and Educational Sciences, University of Leuven (K.U. Leuven), Belgium
| | - Maria Dolores Ledesma
- Centro Biología Molecular "Severo Ochoa" (CSIC-UAM), Campus Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Carlos G Dotti
- Centro Biología Molecular "Severo Ochoa" (CSIC-UAM), Campus Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain.
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Nehmé R, Nehmé H, Saurat T, de-Tauzia ML, Buron F, Lafite P, Verrelle P, Chautard E, Morin P, Routier S, Bénédetti H. New in-capillary electrophoretic kinase assays to evaluate inhibitors of the PI3k/Akt/mTOR signaling pathway. Anal Bioanal Chem 2014; 406:3743-54. [PMID: 24817345 DOI: 10.1007/s00216-014-7790-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 03/24/2014] [Indexed: 01/15/2023]
Abstract
Human kinases are one of the most promising targets for cancer therapy. Methods able to measure the effects of drugs on these cell agents remain crucial for biologists and medicinal chemists. The current work therefore sought to develop an in-capillary enzymatic assay based on capillary electrophoresis (CE) to evaluate the inhibition of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt), and the mammalian target of rapamycin (mTOR). These kinases belong to the same signaling pathway PI3K/Akt/mTOR. For this proposal, the capillary was used as a nanoreactor in which a few nanoliters of the kinase, its substrate, adenosine triphosphate (ATP), and the potent inhibitor were separately injected. A transverse diffusion of laminar flow profiles (TDLFP) approach was employed to mix the reactants. Adenosine diphosphate (ADP ) was detected online at 254 nm. The CE assay was first developed on the α isoform of PI3K. It was compared to five commercial kits frequently used to assess kinase inhibition, based on time-resolved fluorescence resonance energy transfer (TR-FRET) and bioluminescence. Each assay was evaluated in terms of sensitivity (S/B), reproducibility (Z'), and variability (r (2)). This CE method was easily extended to assay the inhibition of the β, γ, and δ isoforms of PI3K, and of the other kinases of the pathway, Akt1 and mTOR, since it is based on in-capillary mixing by TDLFP and on ADP quantification by simple UV absorption. This work shows for the first time the evaluation of inhibitors of the kinases of the PI3K/Akt/mTOR pathway using a common in-capillary CE assay. Several inhibitors with a wide range of affinity toward these enzymes were tested.
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Affiliation(s)
- Reine Nehmé
- Institut de Chimie Organique et Analytique (ICOA), CNRS FR 2708, UMR 7311, Université d'Orléans, Orléans, France,
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25
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Nardi F, Lipina C, Magill D, Hage Hassan R, Hajduch E, Gray A, Hundal HS. Enhanced insulin sensitivity associated with provision of mono and polyunsaturated fatty acids in skeletal muscle cells involves counter modulation of PP2A. PLoS One 2014; 9:e92255. [PMID: 24632852 PMCID: PMC3954878 DOI: 10.1371/journal.pone.0092255] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/19/2014] [Indexed: 11/19/2022] Open
Abstract
AIMS/HYPOTHESIS Reduced skeletal muscle insulin sensitivity is a feature associated with sustained exposure to excess saturated fatty acids (SFA), whereas mono and polyunsaturated fatty acids (MUFA and PUFA) not only improve insulin sensitivity but blunt SFA-induced insulin resistance. The mechanisms by which MUFAs and PUFAs institute these favourable changes remain unclear, but may involve stimulating insulin signalling by counter-modulation/repression of protein phosphatase 2A (PP2A). This study investigated the effects of oleic acid (OA; a MUFA), linoleic acid (LOA; a PUFA) and palmitate (PA; a SFA) in cultured myotubes and determined whether changes in insulin signalling can be attributed to PP2A regulation. PRINCIPAL FINDINGS We treated cultured skeletal myotubes with unsaturated and saturated fatty acids and evaluated insulin signalling, phosphorylation and methylation status of the catalytic subunit of PP2A. Unlike PA, sustained incubation of rat or human myotubes with OA or LOA significantly enhanced Akt- and ERK1/2-directed insulin signalling. This was not due to heightened upstream IRS1 or PI3K signalling nor to changes in expression of proteins involved in proximal insulin signalling, but was associated with reduced dephosphorylation/inactivation of Akt and ERK1/2. Consistent with this, PA reduced PP2Ac demethylation and tyrosine307phosphorylation - events associated with PP2A activation. In contrast, OA and LOA strongly opposed these PA-induced changes in PP2Ac thus exerting a repressive effect on PP2A. CONCLUSIONS/INTERPRETATION Beneficial gains in insulin sensitivity and the ability of unsaturated fatty acids to oppose palmitate-induced insulin resistance in muscle cells may partly be accounted for by counter-modulation of PP2A.
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Affiliation(s)
- Francesca Nardi
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Christopher Lipina
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - David Magill
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Rima Hage Hassan
- Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche des Cordeliers, UMR-S 872, Paris, France
- Université Pierre et Marie Curie – Paris 6, UMR-S 872, Paris, France
- Université Paris Descartes, UMR-S 872, Paris, France
| | - Eric Hajduch
- Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche des Cordeliers, UMR-S 872, Paris, France
- Université Pierre et Marie Curie – Paris 6, UMR-S 872, Paris, France
- Université Paris Descartes, UMR-S 872, Paris, France
| | - Alexander Gray
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Harinder S. Hundal
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, United Kingdom
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Koushik AB, Welter BH, Rock ML, Temesvari LA. A genomewide overexpression screen identifies genes involved in the phosphatidylinositol 3-kinase pathway in the human protozoan parasite Entamoeba histolytica. EUKARYOTIC CELL 2014; 13:401-11. [PMID: 24442890 PMCID: PMC3957588 DOI: 10.1128/ec.00329-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 01/12/2014] [Indexed: 11/20/2022]
Abstract
Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. E. histolytica relies on motility, phagocytosis, host cell adhesion, and proteolysis of extracellular matrix for virulence. In eukaryotic cells, these processes are mediated in part by phosphatidylinositol 3-kinase (PI3K) signaling. Thus, PI3K may be critical for virulence. We utilized a functional genomics approach to identify genes whose products may operate in the PI3K pathway in E. histolytica. We treated a population of trophozoites that were overexpressing genes from a cDNA library with a near-lethal dose of the PI3K inhibitor wortmannin. This screen was based on the rationale that survivors would be overexpressing gene products that directly or indirectly function in the PI3K pathway. We sequenced the overexpressed genes in survivors and identified a cDNA encoding a Rap GTPase, a protein previously shown to participate in the PI3K pathway. This supports the validity of our approach. Genes encoding a coactosin-like protein, EhCoactosin, and a serine-rich E. histolytica protein (SREHP) were also identified. Cells overexpressing EhCoactosin or SREHP were also less sensitive to a second PI3K inhibitor, LY294002. This corroborates the link between these proteins and PI3K. Finally, a mutant cell line with an increased level of phosphatidylinositol (3,4,5)-triphosphate, the product of PI3K activity, exhibited increased expression of SREHP and EhCoactosin. This further supports the functional connection between these proteins and PI3K in E. histolytica. To our knowledge, this is the first forward-genetics screen adapted to reveal genes participating in a signal transduction pathway in this pathogen.
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Affiliation(s)
- Amrita B. Koushik
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
- Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, South Carolina, USA
| | - Brenda H. Welter
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA
- Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, South Carolina, USA
| | - Michelle L. Rock
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA
- Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, South Carolina, USA
| | - Lesly A. Temesvari
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA
- Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, South Carolina, USA
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Yang C, Li Q, Li Y. Targeting nuclear receptors with marine natural products. Mar Drugs 2014; 12:601-35. [PMID: 24473166 PMCID: PMC3944506 DOI: 10.3390/md12020601] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 12/20/2013] [Accepted: 01/07/2014] [Indexed: 02/07/2023] Open
Abstract
Nuclear receptors (NRs) are important pharmaceutical targets because they are key regulators of many metabolic and inflammatory diseases, including diabetes, dyslipidemia, cirrhosis, and fibrosis. As ligands play a pivotal role in modulating nuclear receptor activity, the discovery of novel ligands for nuclear receptors represents an interesting and promising therapeutic approach. The search for novel NR agonists and antagonists with enhanced selectivities prompted the exploration of the extraordinary chemical diversity associated with natural products. Recent studies involving nuclear receptors have disclosed a number of natural products as nuclear receptor ligands, serving to re-emphasize the translational possibilities of natural products in drug discovery. In this review, the natural ligands of nuclear receptors will be described with an emphasis on their mechanisms of action and their therapeutic potentials, as well as on strategies to determine potential marine natural products as nuclear receptor modulators.
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Affiliation(s)
- Chunyan Yang
- State Key Laboratory of Cellular Stress Biology, Innovation Center of Cell Biology Research, School of Life Sciences, Xiamen University, Xiamen 361102, China.
| | - Qianrong Li
- State Key Laboratory of Cellular Stress Biology, Innovation Center of Cell Biology Research, School of Life Sciences, Xiamen University, Xiamen 361102, China.
| | - Yong Li
- State Key Laboratory of Cellular Stress Biology, Innovation Center of Cell Biology Research, School of Life Sciences, Xiamen University, Xiamen 361102, China.
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28
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Xu JX, Si M, Zhang HR, Chen XJ, Zhang XD, Wang C, Du XN, Zhang HL. Phosphoinositide kinases play key roles in norepinephrine- and angiotensin II-induced increase in phosphatidylinositol 4,5-bisphosphate and modulation of cardiac function. J Biol Chem 2014; 289:6941-6948. [PMID: 24448808 DOI: 10.1074/jbc.m113.527952] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The seemly paradoxical Gq agonist-stimulated phosphoinositide production has long been known, but the underlying mechanism and its physiological significance are not known. In this study, we studied cardiac phosphoinositide levels in both cells and whole animals under the stimulation of norepinephrine (NE), angiotensin II (Ang II), and other physiologically relevant interventions. The results demonstrated that activation of membrane receptors related to NE or Ang II caused an initial increase and a later fall in phosphatidylinositol 4,5-bisphosphate (PIP2) levels in the primary cultured cardiomyocytes from adult rats. The possible mechanism underlying this increase in PIP2 was found to be through an enhanced activity of phosphatidylinositol 4-kinase IIIβ, which was mediated by an up-regulated interaction between phosphatidylinositol 4-kinase IIIβ and PKC; the increased activity of phosphatidylinositol 4-phosphate 5-kinase γ was also involved for NE-induced increase of PIP2. When the systolic functions of the NE/Ang II-treated cells were measured, a maintained or failed contractility was found to be correlated with a rise or fall in corresponding PIP2 levels. In two animal models of cardiac hypertrophy, PIP2 levels were significantly reduced in hypertrophic hearts induced by isoprenaline but not in those induced by swimming exercise. This study describes a novel mechanism for phosphoinositide metabolism and modulation of cardiac function.
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Affiliation(s)
- Jia-Xi Xu
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Man Si
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Hui-Ran Zhang
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Xing-Juan Chen
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Xi-Dong Zhang
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Chuan Wang
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Xiao-Na Du
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Hai-Lin Zhang
- Key Laboratory of Neural and Vascular Biology, Ministry of Education, the Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050017, China.
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29
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Structural basis of PI(4,5)P2-dependent regulation of GluA1 by phosphatidylinositol-5-phosphate 4-kinase, type II, alpha (PIP5K2A). Pflugers Arch 2014; 466:1885-97. [PMID: 24389605 PMCID: PMC4159565 DOI: 10.1007/s00424-013-1424-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/21/2013] [Accepted: 12/08/2013] [Indexed: 12/19/2022]
Abstract
Ionotropic glutamate receptors are the most important excitatory receptors in the central nervous system, and their impairment can lead to multiple neuronal diseases. Here, we show that glutamate-induced currents in oocytes expressing GluA1 are increased by coexpression of the schizophrenia-associated phosphoinositide kinase PIP5K2A. This effect was due to enhanced membrane abundance and was blunted by a point mutation (N251S) in PIP5K2A. An increase in GluA1 currents was also observed upon acute injection of PI(4,5)P2, the main product of PIP5K2A. By expression of wild-type and mutant PIP5K2A in human embryonic kidney cells, we were able to provide evidence of impaired kinase activity of the mutant PIP5K2A. We defined the region K813–K823 of GluA1 as critical for the PI(4,5)P2 effect by performing an alanine scan that suggested PI(4,5)P2 binding to this area. A PIP strip assay revealed PI(4,5)P2 binding to the C-terminal GluA1 peptide. The present observations disclose a novel mechanism in the regulation of GluA1.
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Yanamandra M, Kole L, Giri A, Mitra S. Development of phosphocellulose paper-based screening of inhibitors of lipid kinases: case study with PI3Kβ. Anal Biochem 2013; 449:132-8. [PMID: 24380788 DOI: 10.1016/j.ab.2013.12.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 12/18/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Abstract
The phosphatidylinositol 3-kinases (PI3Ks) are lipid kinases that regulate the cellular signal transduction pathways involved in cell growth, proliferation, survival, apoptosis, and adhesion. Deregulation of these pathways are common in oncogenesis, and they are known to be altered in other metabolic disorders as well. Despite its huge potential as an attractive target in these diseases, there is an unmet need for the development of a successful inhibitor. Unlike protein kinase inhibitors, screening for lipid kinase inhibitors has been challenging. Here we report, for the first time, the development of a radioactive lipid kinase screening platform using a phosphocellulose plate that involves transfer of radiolabeled [γ-(32)P]ATP to phosphatidylinositol 4,5-phosphate forming phosphatidylinositol 3,4,5-phosphate, captured on the phosphocellulose plate. Enzyme kinetics and inhibitory properties were established in the plate format using standard inhibitors, such as LY294002, TGX-221, and wortmannin, having different potencies toward PI3K isoforms. ATP and lipid apparent Km for both were determined and IC50 values generated that matched the historical data. Here we report the use of a phosphocellulose plate for a lipid kinase assay (PI3Kβ as the target) as an excellent platform for the identification of novel chemical entities in PI3K drug discovery.
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Affiliation(s)
- Mahesh Yanamandra
- Biology Division, GVK Biosciences Pvt. Ltd., Hyderabad 500076, Andhra Pradesh, India; Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, 500085 Hyderabad, Andhra Pradesh, India
| | - Labanyamoy Kole
- VINS BIO, Kothur Mandal, Mahaboobnagar District 509325, Andhra Pradesh, India
| | - Archana Giri
- Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, 500085 Hyderabad, Andhra Pradesh, India
| | - Sayan Mitra
- Biology Division, GVK Biosciences Pvt. Ltd., Hyderabad 500076, Andhra Pradesh, India.
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31
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Vinuela-Fernandez I, Sun L, Jerina H, Curtis J, Allchorne A, Gooding H, Rosie R, Holland P, Tas B, Mitchell R, Fleetwood-Walker S. The TRPM8 channel forms a complex with the 5-HT(1B) receptor and phospholipase D that amplifies its reversal of pain hypersensitivity. Neuropharmacology 2013; 79:136-51. [PMID: 24269608 DOI: 10.1016/j.neuropharm.2013.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 10/07/2013] [Accepted: 11/11/2013] [Indexed: 12/25/2022]
Abstract
Effective relief from chronic hypersensitive pain states remains an unmet need. Here we report the discovery that the TRPM8 ion channel, co-operating with the 5-HT(1B) receptor (5-HT(1B)R) in a subset of sensory afferents, exerts an influence at the spinal cord level to suppress central hypersensitivity in pain processing throughout the central nervous system. Using cell line models, ex vivo rat neural tissue and in vivo pain models, we assessed functional Ca(2+) fluorometric responses, protein:protein interactions, immuno-localisation and reflex pain behaviours, with pharmacological and molecular interventions. We report 5-HT(1B)R expression in many TRPM8-containing afferents and direct interaction of these proteins in a novel multi-protein signalling complex, which includes phospholipase D1 (PLD1). We provide evidence that the 5-HT(1B)R activates PLD1 to subsequently activate PIP 5-kinase and generate PIP2, an allosteric enhancer of TRPM8, achieving a several-fold increase in potency of TRPM8 activation. The enhanced activation responses of synaptoneurosomes prepared from spinal cord and cortical regions of animals with a chronic inflammatory pain state are inhibited by TRPM8 activators that were applied in vivo topically to the skin, an effect potentiated by co-administered 5-HT(1B)R agonists and attenuated by 5-HT(1B)R antagonists, while 5-HT(1B)R agents alone had no detectable effect. Corresponding results are seen when assessing reflex behaviours in inflammatory and neuropathic pain models. Control experiments with alternative receptor/TRP channel combinations reveal no such synergy. Identification of this novel receptor/effector/channel complex and its impact on nociceptive processing give new insights into possible strategies for enhanced analgesia in chronic pain.
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Affiliation(s)
- Ignacio Vinuela-Fernandez
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Liting Sun
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Helen Jerina
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - John Curtis
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Andrew Allchorne
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Hayley Gooding
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Roberta Rosie
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Pamela Holland
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Basak Tas
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Rory Mitchell
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom.
| | - Sue Fleetwood-Walker
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom.
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Hoxhaj G, Dissanayake K, MacKintosh C. Effect of IRS4 levels on PI 3-kinase signalling. PLoS One 2013; 8:e73327. [PMID: 24039912 PMCID: PMC3769281 DOI: 10.1371/journal.pone.0073327] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 07/25/2013] [Indexed: 11/20/2022] Open
Abstract
Insulin receptor substrate 1 (IRS1) and IRS2 are well-characterized adapter proteins that relay signals from receptor tyrosine kinases to downstream components of signalling pathways. In contrast, the function of IRS4 is not well understood. IRS4 overexpression has been associated with acute lymphoblastic leukaemia and subungual exostosis, while point mutations of IRS4 have been found in melanomas. Here, we show that while IRS4 expression is low in most cancer cell lines, IRS4 mRNA and protein levels are markedly elevated in certain cells including the NCI-H720, DMS114, HEK293T and HEK293AAV lines. Surprisingly, IRS4 expression was also strongly induced when HEK293 cells were infected with retroviral particles and selected under puromycin, making IRS4 expression a potential off-target effect of retroviral expression vectors. Cells with high expression of IRS4 displayed high phosphatidylinositol (3,4,5)-trisphosphate (PIP3) levels, as well as elevated Akt and p70 S6 kinase activities, even in the absence of growth factors. PI 3-kinase (PI3K) signalling in these cells depends on IRS4, even though these cells also express IRS1/2. Knockdown of IRS4 also inhibited cell proliferation in cells with high levels of IRS4. Together, these findings suggest IRS4 as a potential therapeutic target for cancers with high expression of this protein.
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Affiliation(s)
- Gerta Hoxhaj
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Kumara Dissanayake
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Carol MacKintosh
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
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33
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Cross talk between the Akt and p38α pathways in macrophages downstream of Toll-like receptor signaling. Mol Cell Biol 2013; 33:4152-65. [PMID: 23979601 DOI: 10.1128/mcb.01691-12] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The stimulation of Toll-like receptors (TLRs) on macrophages by pathogen-associated molecular patterns (PAMPs) results in the activation of intracellular signaling pathways that are required for initiating a host immune response. Both phosphatidylinositol 3-kinase (PI3K)-Akt and p38 mitogen-activated protein kinase (MAPK) signaling pathways are activated rapidly in response to TLR activation and are required to coordinate effective host responses to pathogen invasion. In this study, we analyzed the role of the p38-dependent kinases MK2/3 in the activation of Akt and show that lipopolysaccharide (LPS)-induced phosphorylation of Akt on Thr308 and Ser473 requires p38α and MK2/3. In cells treated with p38 inhibitors or an MK2/3 inhibitor, phosphorylation of Akt on Ser473 and Thr308 is reduced and Akt activity is inhibited. Furthermore, BMDMs deficient in MK2/3 display greatly reduced phosphorylation of Ser473 and Thr308 following TLR stimulation. However, MK2/3 do not directly phosphorylate Akt in macrophages but act upstream of PDK1 and mTORC2 to regulate Akt phosphorylation. Akt is recruited to phosphatidylinositol 3,4,5-trisphosphate (PIP3) in the membrane, where it is activated by PDK1 and mTORC2. Analysis of lipid levels in MK2/3-deficient bone marrow-derived macrophages (BMDMs) revealed a role for MK2/3 in regulating Akt activity by affecting availability of PIP3 at the membrane. These data describe a novel role for p38α-MK2/3 in regulating TLR-induced Akt activation in macrophages.
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34
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PDK1 controls upstream PI3K expression and PIP3 generation. Oncogene 2013; 33:3043-53. [PMID: 23893244 DOI: 10.1038/onc.2013.266] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 04/30/2013] [Accepted: 05/20/2013] [Indexed: 12/17/2022]
Abstract
The PI3K/PDK1/Akt signaling axis is centrally involved in cellular homeostasis and controls cell growth and proliferation. Due to its key function as regulator of cell survival and metabolism, the dysregulation of this pathway is manifested in several human pathologies including cancers and immunological diseases. Thus, current therapeutic strategies target the components of this signaling cascade. In recent years, numerous feedback loops have been identified that attenuate PI3K/PDK1/Akt-dependent signaling. Here, we report the identification of an additional level of feedback regulation that depends on the negative transcriptional control of phosphatidylinositol 3-kinase (PI3K) class IA subunits. Genetic deletion of 3-phosphoinositide-dependent protein kinase 1 (PDK1) or the pharmacological inhibition of its downstream effectors, that is, Akt and mammalian target of rapamycin (mTOR), relieves this suppression and leads to the upregulation of PI3K subunits, resulting in enhanced generation of phosphatidylinositol-3,4,5-trisphosphate (PIP3). Apparently, this transcriptional induction is mediated by the concerted action of different transcription factor families, including the transcription factors cAMP-responsive element-binding protein and forkhead box O. Collectively, we propose that PDK1 functions as a cellular sensor that balances basal PIP3 generation at levels sufficient for survival but below a threshold being harmful to the cell. Our study suggests that the efficiency of therapies targeting the aberrantly activated PI3K/PDK1/Akt pathway might be increased by the parallel blockade of feedback circuits.
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Zhang L, Malik S, Pang J, Wang H, Park KM, Yule DI, Blaxall BC, Smrcka AV. Phospholipase Cε hydrolyzes perinuclear phosphatidylinositol 4-phosphate to regulate cardiac hypertrophy. Cell 2013; 153:216-27. [PMID: 23540699 DOI: 10.1016/j.cell.2013.02.047] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 01/22/2013] [Accepted: 02/14/2013] [Indexed: 01/08/2023]
Abstract
Phospholipase Cε (PLCε) is a multifunctional enzyme implicated in cardiovascular, pancreatic, and inflammatory functions. Here we show that conditional deletion of PLCε in mouse cardiac myocytes protects from stress-induced pathological hypertrophy. PLCε small interfering RNA (siRNA) in ventricular myocytes decreases endothelin-1 (ET-1)-dependent elevation of nuclear calcium and activation of nuclear protein kinase D (PKD). PLCε scaffolded to muscle-specific A kinase-anchoring protein (mAKAP), along with PKCε and PKD, localizes these components at or near the nuclear envelope, and this complex is required for nuclear PKD activation. Phosphatidylinositol 4-phosphate (PI4P) is identified as a perinuclear substrate in the Golgi apparatus for mAKAP-scaffolded PLCε. We conclude that perinuclear PLCε, scaffolded to mAKAP in cardiac myocytes, responds to hypertrophic stimuli to generate diacylglycerol (DAG) from PI4P in the Golgi apparatus, in close proximity to the nuclear envelope, to regulate activation of nuclear PKD and hypertrophic signaling pathways.
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Affiliation(s)
- Lianghui Zhang
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
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36
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Cho H, Wu M, Bilgin B, Walton SP, Chan C. Latest developments in experimental and computational approaches to characterize protein-lipid interactions. Proteomics 2013; 12:3273-85. [PMID: 22997137 DOI: 10.1002/pmic.201200255] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 08/30/2012] [Accepted: 09/05/2012] [Indexed: 12/16/2022]
Abstract
Understanding the functional roles of all the molecules in cells is an ultimate goal of modern biology. An important facet is to understand the functional contributions from intermolecular interactions, both within a class of molecules (e.g. protein-protein) or between classes (e.g. protein-DNA). While the technologies for analyzing protein-protein and protein-DNA interactions are well established, the field of protein-lipid interactions is still relatively nascent. Here, we review the current status of the experimental and computational approaches for detecting and analyzing protein-lipid interactions. Experimental technologies fall into two principal categories, namely solution-based and array-based methods. Computational methods include large-scale data-driven analyses and predictions/dynamic simulations based on prior knowledge of experimentally identified interactions. Advances in the experimental technologies have led to improved computational analyses and vice versa, thereby furthering our understanding of protein-lipid interactions and their importance in biological systems.
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Affiliation(s)
- Hyunju Cho
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI, USA
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37
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Muscolini M, Camperio C, Capuano C, Caristi S, Piccolella E, Galandrini R, Tuosto L. Phosphatidylinositol 4-Phosphate 5-Kinase α Activation Critically Contributes to CD28-Dependent Signaling Responses. THE JOURNAL OF IMMUNOLOGY 2013; 190:5279-86. [DOI: 10.4049/jimmunol.1203157] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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38
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Abstract
BACKGROUND Homogeneous time-resolved fluorescence (HTRF) is a fluorescence resonance energy transfer-based technology used to measure bimolecular interactions. It has been applied successfully to kinase assays and has become an important tool in kinase drug discovery. OBJECTIVE This article reviews the current status of HTRF technology in biochemical and cellular kinase assays. METHODS Recent literature and meeting reports on HTRF kinase assays are reviewed, and their principles, advantages and drawbacks, current status and the potential applications in kinase drug discovery are discussed. RESULTS/CONCLUSION HTRF kinase assays are homogeneous, robust, sensitive, easy to miniaturize and high-throughput. This assay format is versatile, as both peptide and protein substrates can be used, and high ATP concentrations are tolerated, which enables the assay to be performed under conditions mimicking the physiological environment. HTRF kinase assays have been applied to both high-throughput screening and compound mechanistic studies. Besides protein kinases, the technology has now been expanded into the lipid kinase family. Furthermore, the utility of HTRF technology in cellular assays is emerging. HTRF kinase assays are a great addition to the toolbox for kinase drug discovery.
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Affiliation(s)
- Yong Jia
- Group Leader Genomics Institute of the Novartis Research Foundation, Department of Kinase Biology, 10675 John J Hopkins Dr, San Diego, CA 92121, USA +858 812 1728 ; +858 812 1918 ;
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39
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Trovò L, Ahmed T, Callaerts-Vegh Z, Buzzi A, Bagni C, Chuah M, Vandendriessche T, D'Hooge R, Balschun D, Dotti CG. Low hippocampal PI(4,5)P₂ contributes to reduced cognition in old mice as a result of loss of MARCKS. Nat Neurosci 2013; 16:449-55. [PMID: 23434911 DOI: 10.1038/nn.3342] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 01/18/2013] [Indexed: 02/03/2023]
Abstract
Cognitive and motor performances decline during aging. Although it is clear that such signs reflect synaptic compromise, the underlying mechanisms have not been defined. We found that the levels and activity of the synaptic plasticity modulators phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P₂) and phospholipase Cγ (PLCγ) were substantially reduced in hippocampal synaptic membranes from old mice. In addition, these membranes contained reduced levels of the PI(4,5)P₂-clustering molecule myristoylated alanine-rich C kinase substrate (MARCKS). Consistent with a cause-effect relationship, raising MARCKS levels in the brain of old mice led to increased synaptic membrane clustering of PI(4,5)P₂ and to PLCγ activation. MARCKS overexpression in the hippocampus of old mice or intraventricular perfusion of MARCKS peptide resulted in enhanced long-term potentiation and improved memory. These results reveal one of the mechanisms involved in brain dysfunction during aging.
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Affiliation(s)
- Laura Trovò
- VIB Center for the Biology of Disease, Leuven and Center for Human Genetics, University of Leuven (Katholieke University of Leuven), Leuven, Belgium
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40
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Yu H, Moore ML, Erhard K, Hardwicke MA, Lin H, Luengo JI, McSurdy-Freed J, Plant R, Qu J, Raha K, Rominger CM, Schaber MD, Spengler MD, Rivero RA. [3a,4]-Dihydropyrazolo[1,5a]pyrimidines: Novel, Potent, and Selective Phosphatidylinositol-3-kinase β Inhibitors. ACS Med Chem Lett 2013; 4:230-4. [PMID: 24900655 DOI: 10.1021/ml300330m] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/10/2013] [Indexed: 01/31/2023] Open
Abstract
A series of novel [3a,4]dihydropyrazolo[1,5a]pyrimidines were identified, which were highly potent and selective inhibitors of PI3Kβ. The template afforded the opportunity to develop novel SAR for both the hinge-binding (R3) and back-pocket (R4) substitutents. While cellular potency was relatively modest due to high protein binding, the series displayed low clearance in rat, mouse, and monkey.
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Affiliation(s)
- Hongyi Yu
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Michael L. Moore
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Karl Erhard
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Mary Ann Hardwicke
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Hong Lin
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Juan I. Luengo
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Jeanelle McSurdy-Freed
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Ramona Plant
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Junya Qu
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Kaushik Raha
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Cynthia M. Rominger
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Michael D. Schaber
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Michael D. Spengler
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
| | - Ralph A. Rivero
- Cancer
Metabolism Chemistry, ‡Cancer Metabolism Biology, §Cancer Metabolism DMPK, ∥Computational Chemistry,
Platform Technology Sciences, and ⊥Screening and Compound Profiling, Platform
Technology Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426,
United States
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41
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Wang X, Wang L, Zhu L, Pan Y, Xiao F, Liu W, Wang Z, Guo F, Liu Y, Thomas WG, Chen Y. PAQR3 modulates insulin signaling by shunting phosphoinositide 3-kinase p110α to the Golgi apparatus. Diabetes 2013; 62:444-56. [PMID: 23086038 PMCID: PMC3554364 DOI: 10.2337/db12-0244] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Phosphoinositide 3-kinase (PI3K) mediates insulin actions by relaying signals from insulin receptors (IRs) to downstream targets. The p110α catalytic subunit of class IA PI3K is the primary insulin-responsive PI3K implicated in insulin signaling. We demonstrate here a new mode of spatial regulation for the p110α subunit of PI3K by PAQR3 that is exclusively localized in the Golgi apparatus. PAQR3 interacts with p110α, and the intracellular targeting of p110α to the Golgi apparatus is reduced by PAQR3 downregulation and increased by PAQR3 overexpression. Insulin-stimulated PI3K activity and phosphoinositide (3,4,5)-triphosphate production are enhanced by Paqr3 deletion and reduced by PAQR3 overexpression in hepatocytes. Deletion of Paqr3 enhances insulin-stimulated phosphorylation of AKT and glycogen synthase kinase 3β, but not phosphorylation of IR and IR substrate-1 (IRS-1), in hepatocytes, mouse liver, and skeletal muscle. Insulin-stimulated GLUT4 translocation to the plasma membrane and glucose uptake are enhanced by Paqr3 ablation. Furthermore, PAQR3 interacts with the domain of p110α involved in its binding with p85, the regulatory subunit of PI3K. Overexpression of PAQR3 dose-dependently reduces the interaction of p85α with p110α. Thus, PAQR3 negatively regulates insulin signaling by shunting cytosolic p110α to the Golgi apparatus while competing with p85 subunit in forming a PI3K complex with p110α.
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Affiliation(s)
- Xiao Wang
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Lingdi Wang
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Lu Zhu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Yi Pan
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Fei Xiao
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Weizhong Liu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Zhenzhen Wang
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Feifan Guo
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Yong Liu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | - Walter G. Thomas
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Yan Chen
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
- Corresponding author: Yan Chen,
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42
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Özbalci C, Sachsenheimer T, Brügger B. Quantitative analysis of cellular lipids by nano-electrospray ionization mass spectrometry. Methods Mol Biol 2013; 1033:3-20. [PMID: 23996167 DOI: 10.1007/978-1-62703-487-6_1] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Lipid analysis performed by nano-electrospray ionization mass spectrometry is a highly sensitive method for quantification of lipids including all lipid species of a given lipid class. Various instrumental setups are used for quantitative lipid analysis, including different modes of ionization, separation, and detection. Here we describe a work-flow for the rapid and quantitative analysis of lipid species from cellular membranes by direct infusion of lipid extracts to a nano-electrospray ionization triple quadrupole/linear ion trap mass spectrometer.
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Affiliation(s)
- Cagakan Özbalci
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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43
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Popovics P, Gray A, Arastoo M, Finelli DK, Tan AJL, Stewart AJ. Phospholipase C-η2 is required for retinoic acid-stimulated neurite growth. J Neurochem 2012; 124:632-44. [PMID: 23237262 DOI: 10.1111/jnc.12122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 11/21/2012] [Accepted: 12/10/2012] [Indexed: 01/30/2023]
Abstract
Phospholipase C-η2 is a recently identified phospholipase C (PLC) implicated in the regulation of neuronal differentiation/maturation. PLCη2 activity is triggered by intracellular calcium mobilization and likely serves to amplify Ca²⁺ signals by stimulating further Ca²⁺ release from Ins(1,4,5)P₃-sensitive stores. The role of PLCη2 in neuritogenesis was assessed during retinoic acid (RA)-induced Neuro2A cell differentiation. PLCη2 expression increased two-fold during a 4-day differentiation period. Stable expression of PLCη2-targetted shRNA led to a decrease in the number of differentiated cells and total length of neurites following RA-treatment. Furthermore, RA response element activation was perturbed by PLCη2 knockdown. Using a bacterial two-hybrid screen, we identified LIM domain kinase 1 (LIMK1) as a putative interaction partner of PLCη2. Immunostaining of PLCη2 revealed significant co-localization with LIMK1 in the nucleus and growing neurites in Neuro2A cells. RA-induced phosphorylation of LIMK1 and cAMP-responsive element-binding protein was reduced in PLCη2 knock-down cells. The phosphoinositide-binding properties of the PLCη2 PH domain, assessed using a FRET-based assay, revealed this domain to possess a high affinity toward PtdIns(3,4,5)P₃. Immunostaining of PLCη2 together with PtdIns(3,4,5)P₃ in the Neuro2A cells revealed a high degree of co-localization, indicating that PtdIns(3,4,5)P₃ levels in cellular compartments are likely to be important for the spatial control of PLCη2 signaling.
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Affiliation(s)
- Petra Popovics
- School of Medicine, Medical and Biological Sciences Building, North Haugh, University of St Andrews, St Andrews, Fife, UK
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44
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Ying WZ, Aaron KJ, Sanders PW. Effect of aging and dietary salt and potassium intake on endothelial PTEN (Phosphatase and tensin homolog on chromosome 10) function. PLoS One 2012; 7:e48715. [PMID: 23144940 PMCID: PMC3492426 DOI: 10.1371/journal.pone.0048715] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 09/28/2012] [Indexed: 11/19/2022] Open
Abstract
Aging promotes endothelial dysfunction, defined as a reduction in bioavailable nitric oxide (NO) produced by the endothelial isoform of nitric oxide synthase (NOS3). This enzyme is critically regulated by phosphorylation by protein kinase B (Akt), which in turn is regulated by the lipid phosphatase, PTEN. The present series of studies demonstrated a reduction in bioavailable NO as the age of rats increased from 1 to 12 months. At 12 months of age, rats no longer demonstrated increases in phosphorylated NOS3 in response to high dietary salt intake. Endothelial cell levels of PTEN increased with age and became refractory to change with increased salt intake. In contrast to the reduction in NO production, endothelial cell production of transforming growth factor-ß (TGF-ß) relative to NO increased progressively with age. In macrovascular endothelial cells, PTEN was regulated in a dose-dependent fashion by TGF-ß, which was further regulated by extracellular [KCl]. When combined with prior studies, the present series of experiments suggested an integral role for PTEN in endothelial cell pathobiology of aging and an important mitigating function of TGF-ß in endothelial PTEN regulation. The findings further supported a role for diet in affecting vascular function through the production of TGF-ß and NO.
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Affiliation(s)
- Wei-Zhong Ying
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, Center for Free Radical Biology, Center for Aging, and Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Kristal J. Aaron
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, Center for Free Radical Biology, Center for Aging, and Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Paul W. Sanders
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, Center for Free Radical Biology, Center for Aging, and Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Veterans Affairs Medical Center, Birmingham, Alabama, United States of America
- * E-mail:
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45
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Wang K, Jiang D, Sims CE, Allbritton NL. Separation of fluorescently labeled phosphoinositides and sphingolipids by capillary electrophoresis. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 907:79-86. [PMID: 23000742 PMCID: PMC3475496 DOI: 10.1016/j.jchromb.2012.09.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/20/2012] [Accepted: 09/03/2012] [Indexed: 12/16/2022]
Abstract
Phosphoinositides (PIs) and sphingolipids regulate many aspects of cell behavior and are often involved in disease processes such as oncogenesis. Capillary electrophoresis with laser induced fluorescence detection (CE-LIF) is emerging as an important tool for enzymatic assays of the metabolism of these lipids, particularly in cell-based formats. Previous separations of phosphoinositide lipids by CE required a complex buffer with polymer additives which had the disadvantages of high cost and/or short shelf life. Further a simultaneous separation of these classes of lipids has not been demonstrated in a robust buffer system. In the current work, a simple separation buffer based on NaH(2)PO(4) and 1-propanol was optimized to separate two sphingolipids and multiple phosphoinositides by CE. The NaH(2)PO(4) concentration, pH, 1-propanol fraction, and a surfactant additive to the buffer were individually optimized to achieve simultaneous separation of the sphingolipids and phosphoinositides. Fluorescein-labeled sphingosine (SFL) and sphingosine 1-phosphate (S1PFL), fluorescein-labeled phosphatidyl-inositol 4,5-bisphosphate (PIP2) and phosphatidyl-inositol 3,4,5-trisphosphate (PIP3), and bodipy-fluorescein (BFL)-labeled PIP2 and PIP3 were separated pairwise and in combination to demonstrate the generalizability of the method. Theoretical plate numbers achieved were as high as 2×10(5) in separating fluorophore-labeled PIP2 and PIP3. Detection limits for the 6 analytes were in the range of 10(-18)-10(-20)mol. The method also showed high reproducibility, as the relative standard deviation of the normalized migration time for each analyte in the simultaneous separation of all 6 compounds was less than 1%. The separation of a mixture composed of diacylglycerol (DAG) and multiple phosphoinositides was also demonstrated. As a final test, fluorescent lipid metabolites formed within cells loaded with BFLPIP2 were separated from a cell lysate as well as a single cell. This simple and robust separation method for SFL and S1PFL and various metabolites of phosphoinositide-related signal transduction is expected to enable improved enzymatic assays for biological and clinical applications.
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Affiliation(s)
- Kelong Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599
| | - Dechen Jiang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599
| | - Christopher E. Sims
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, 27599 and North Carolina State University, Raleigh, NC 27695
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46
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Wymann MP, Schultz C. The chemical biology of phosphoinositide 3-kinases. Chembiochem 2012; 13:2022-35. [PMID: 22965647 DOI: 10.1002/cbic.201200089] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 07/13/2012] [Indexed: 01/14/2023]
Abstract
Since its discovery in the late 1980s, phosphoinositide 3-kinase (PI3K), and its isoforms have arguably reached the forefront of signal transduction research. Regulation of this lipid kinase, its functions, its effectors, in short its entire signaling network, has been extensively studied. PI3K inhibitors are frequently used in biochemistry and cell biology. In addition, many pharmaceutical companies have launched drug-discovery programs to identify modulators of PI3Ks. Despite these efforts and a fairly good knowledge of the PI3K signaling network, we still have only a rudimentary picture of the signaling dynamics of PI3K and its lipid products in space and time. It is therefore essential to create and use novel biological and chemical tools to manipulate the phosphoinositide signaling network with spatial and temporal resolution. In this review, we discuss the current and potential future tools that are available and necessary to unravel the various functions of PI3K and its isoforms.
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Affiliation(s)
- Matthias P Wymann
- Institute of Biochemistry & Genetics, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
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47
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Lin H, Schulz MJ, Xie R, Zeng J, Luengo JI, Squire MD, Tedesco R, Qu J, Erhard K, Mack JF, Raha K, Plant R, Rominger CM, Ariazi JL, Sherk CS, Schaber MD, McSurdy-Freed J, Spengler MD, Davis CB, Hardwicke MA, Rivero RA. Rational Design, Synthesis, and SAR of a Novel Thiazolopyrimidinone Series of Selective PI3K-beta Inhibitors. ACS Med Chem Lett 2012; 3:524-9. [PMID: 24900504 DOI: 10.1021/ml300045b] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 05/29/2012] [Indexed: 11/29/2022] Open
Abstract
A novel thiazolopyrimidinone series of PI3K-beta selective inhibitors has been identified. This chemotype has provided an excellent tool compound, 18, that showed potent growth inhibition in the PTEN-deficient breast cancer cell line MDA-MB-468 under anchorage-independent conditions, and it also demonstrated pharmacodynamic effects and efficacy in a PTEN-deficient prostate cancer PC-3 xenograft mouse model.
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Affiliation(s)
- Hong Lin
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Mark J. Schulz
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Ren Xie
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Jin Zeng
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Juan I. Luengo
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Michael D. Squire
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Rosanna Tedesco
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Junya Qu
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Karl Erhard
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - James F. Mack
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Kaushik Raha
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Ramona Plant
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Cynthia M. Rominger
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Jennifer L. Ariazi
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Christian S. Sherk
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Michael D. Schaber
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Jeanelle McSurdy-Freed
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Michael D. Spengler
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Charles B. Davis
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Mary Ann Hardwicke
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Ralph A. Rivero
- Cancer Metabolism Chemistry; ‡Cancer Metabolism Biology; §Cancer Metabolism DMPK; ∥Platform Technology Sciences—Computational Chemistry; and ⊥Platform Technology Sciences—Screening & Compound Profiling; GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
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48
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Dixon MJ, Gray A, Schenning M, Agacan M, Tempel W, Tong Y, Nedyalkova L, Park HW, Leslie NR, van Aalten DMF, Downes CP, Batty IH. IQGAP proteins reveal an atypical phosphoinositide (aPI) binding domain with a pseudo C2 domain fold. J Biol Chem 2012; 287:22483-96. [PMID: 22493426 PMCID: PMC3391087 DOI: 10.1074/jbc.m112.352773] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/26/2012] [Indexed: 01/22/2023] Open
Abstract
Class I phosphoinositide (PI) 3-kinases act through effector proteins whose 3-PI selectivity is mediated by a limited repertoire of structurally defined, lipid recognition domains. We describe here the lipid preferences and crystal structure of a new class of PI binding modules exemplified by select IQGAPs (IQ motif containing GTPase-activating proteins) known to coordinate cellular signaling events and cytoskeletal dynamics. This module is defined by a C-terminal 105-107 amino acid region of which IQGAP1 and -2, but not IQGAP3, binds preferentially to phosphatidylinositol 3,4,5-trisphosphate (PtdInsP(3)). The binding affinity for PtdInsP(3), together with other, secondary target-recognition characteristics, are comparable with those of the pleckstrin homology domain of cytohesin-3 (general receptor for phosphoinositides 1), an established PtdInsP(3) effector protein. Importantly, the IQGAP1 C-terminal domain and the cytohesin-3 pleckstrin homology domain, each tagged with enhanced green fluorescent protein, were both re-localized from the cytosol to the cell periphery following the activation of PI 3-kinase in Swiss 3T3 fibroblasts, consistent with their common, selective recognition of endogenous 3-PI(s). The crystal structure of the C-terminal IQGAP2 PI binding module reveals unexpected topological similarity to an integral fold of C2 domains, including a putative basic binding pocket. We propose that this module integrates select IQGAP proteins with PI 3-kinase signaling and constitutes a novel, atypical phosphoinositide binding domain that may represent the first of a larger group, each perhaps structurally unique but collectively dissimilar from the known PI recognition modules.
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Affiliation(s)
| | | | | | - Mark Agacan
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dow St., Dundee DD1 5EH, Scotland, United Kingdom and
| | | | | | | | - Hee-Won Park
- the Structural Genomics Consortium and
- Department of Pharmacology, University of Toronto, Toronto, Ontario M5G 1L5, Canada
| | | | | | | | - Ian H. Batty
- From the Division of Cell Signalling and Immunology and
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49
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Fernández-Acero T, Rodríguez-Escudero I, Vicente F, Monteiro MC, Tormo JR, Cantizani J, Molina M, Cid VJ. A Yeast-Based In Vivo Bioassay to Screen for Class I Phosphatidylinositol 3-Kinase Specific Inhibitors. ACTA ACUST UNITED AC 2012; 17:1018-29. [DOI: 10.1177/1087057112450051] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The phosphatidylinositol 3-kinase (PI3K) pathway couples receptor-mediated signaling to essential cellular functions by generating the lipid second messenger phosphatidylinositol-3,4,5- trisphosphate. This pathway is implicated in multiple aspects of oncogenesis. A low-cost bioassay that readily measures PI3K inhibition in vivo would serve as a valuable tool for research in this field. Using heterologous expression, we have previously reconstituted the PI3K pathway in the model organism Saccharomyces cerevisiae. On the basis of the fact that the overproduction of PI3K is toxic in yeast, we tested the ability of commercial PI3K inhibitors to rescue cell growth. All compounds tested counteracted the PI3K-induced toxicity. Among them, 15e and PI-103 were the most active. Strategies to raise the intracellular drug concentration, specifically the use of 0.003% sodium dodecyl sulfate and the elimination of the Snq2 detoxification pump, optimized the bioassay by enhancing its sensitivity. The humanized yeast-based assay was then tested on a pilot scale for high-throughput screening (HTS) purposes using a collection of natural products of microbial origin. From 9600 extracts tested, 0.6% led to a recovery of yeast growth reproducibly, selectively, and in a dose-dependent manner. Cumulatively, we show that the developed PI3K inhibition bioassay is robust and applicable to large-scale HTS.
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Affiliation(s)
- Teresa Fernández-Acero
- Dpto. Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Plaza de Ramón y Cajal, Madrid, Spain
| | - Isabel Rodríguez-Escudero
- Dpto. Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Plaza de Ramón y Cajal, Madrid, Spain
| | - Francisca Vicente
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico de Ciencias de la Salud, Armilla, Granada, Spain
| | - Maria Cândida Monteiro
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico de Ciencias de la Salud, Armilla, Granada, Spain
| | - José R. Tormo
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico de Ciencias de la Salud, Armilla, Granada, Spain
| | - Juan Cantizani
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico de Ciencias de la Salud, Armilla, Granada, Spain
| | - María Molina
- Dpto. Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Plaza de Ramón y Cajal, Madrid, Spain
| | - Víctor J. Cid
- Dpto. Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Plaza de Ramón y Cajal, Madrid, Spain
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Turban S, Stretton C, Drouin O, Green CJ, Watson ML, Gray A, Ross F, Lantier L, Viollet B, Hardie DG, Marette A, Hundal HS. Defining the contribution of AMP-activated protein kinase (AMPK) and protein kinase C (PKC) in regulation of glucose uptake by metformin in skeletal muscle cells. J Biol Chem 2012; 287:20088-99. [PMID: 22511782 PMCID: PMC3370192 DOI: 10.1074/jbc.m111.330746] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 04/11/2012] [Indexed: 12/25/2022] Open
Abstract
The importance of AMP-activated protein kinase (AMPK) and protein kinase C (PKC) as effectors of metformin (Met) action on glucose uptake (GU) in skeletal muscle cells was investigated. GU in L6 myotubes was stimulated 2-fold following 16 h of Met treatment and acutely enhanced by insulin in an additive fashion. Insulin-stimulated GU was sensitive to PI3K inhibition, whereas that induced by Met was not. Met and its related biguanide, phenformin, stimulated AMPK activation/phosphorylation to a level comparable with that induced by the AMPK activator, 5-amino-1-β-d-ribofuranosyl-imidazole-4-carboxamide (AICAR). However, the increase in GU elicited by AICAR was significantly lower than that induced by either biguanide. Expression of a constitutively active AMPK mimicked the effects of AICAR on GU, whereas a dominant interfering AMPK or shRNA silencing of AMPK prevented AICAR-stimulated GU and Met-induced AMPK signaling but only repressed biguanide-stimulated GU by ∼20%. Consistent with this, analysis of GU in muscle cells from α1(-/-)/α2(-/-) AMPK-deficient mice revealed a significant retention of Met-stimulated GU, being reduced by ∼35% compared with that of wild type cells. Atypical PKCs (aPKCs) have been implicated in Met-stimulated GU, and in line with this, Met and phenformin induced activation/phosphorylation of aPKC in L6 myotubes. However, although cellular depletion of aPKC (>90%) led to loss in biguanide-induced aPKC phosphorylation, it had no effect on Met-stimulated GU, whereas inhibitors targeting novel/conventional PKCs caused a significant reduction in biguanide-induced GU. Our findings indicate that although Met activates AMPK, a significant component of Met-stimulated GU in muscle cells is mediated via an AMPK-independent mechanism that involves novel/conventional PKCs.
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Affiliation(s)
- Sophie Turban
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Clare Stretton
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Olivier Drouin
- the Department of Medicine, Québec Heart and Lung Institute, Université Laval and Metabolism, Vascular, and Renal Health Axis, Laval University Hospital Research Center, Ste-Foy, Québec, G1V 4G2, Canada
| | - Charlotte J. Green
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Maria L. Watson
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Alexander Gray
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Fiona Ross
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Louise Lantier
- INSERM, Institut Cochin, U1016, Paris, France
- CNRS, UMR8104, Paris, France, and
- Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Benoit Viollet
- INSERM, Institut Cochin, U1016, Paris, France
- CNRS, UMR8104, Paris, France, and
- Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - D. Grahame Hardie
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Andre Marette
- the Department of Medicine, Québec Heart and Lung Institute, Université Laval and Metabolism, Vascular, and Renal Health Axis, Laval University Hospital Research Center, Ste-Foy, Québec, G1V 4G2, Canada
| | - Harinder S. Hundal
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
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