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Cook NL, Pjanic M, Emmerich AG, Rao AS, Hetty S, Knowles JW, Quertermous T, Castillejo-López C, Ingelsson E. CRISPR-Cas9-mediated knockout of SPRY2 in human hepatocytes leads to increased glucose uptake and lipid droplet accumulation. BMC Endocr Disord 2019; 19:115. [PMID: 31664995 PMCID: PMC6820957 DOI: 10.1186/s12902-019-0442-8] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/10/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The prevalence of obesity and its comorbidities, including type 2 diabetes mellitus (T2DM), is dramatically increasing throughout the world; however, the underlying aetiology is incompletely understood. Genome-wide association studies (GWAS) have identified hundreds of genec susceptibility loci for obesity and T2DM, although the causal genes and mechanisms are largely unknown. SPRY2 is a candidate gene identified in GWAS of body fat percentage and T2DM, and has recently been linked to insulin production in pancreatic β-cells. In the present study, we aimed to further understand SPRY2 via functional characterisation in HepG2 cells, an in vitro model of human hepatocytes widely used to investigate T2DM and insulin resistance. METHODS CRISPR-Cas9 genome editing was used to target SPRY2 in HepG2 cells, and the functional consequences of SPRY2 knockout (KO) and overexpression subsequently assessed using glucose uptake and lipid droplet assays, measurement of protein kinase phosphorylation and RNA sequencing. RESULTS The major functional consequence of SPRY2 KO was a significant increase in glucose uptake, along with elevated lipid droplet accumulation. These changes were attenuated, but not reversed, in cells overexpressing SPRY2. Phosphorylation of protein kinases across key signalling pathways (including Akt and mitogen activated protein kinases) was not altered after SPRY2 KO. Transcriptome profiling in SPRY2 KO and mock (control) cells revealed a number of differentially expressed genes related to cholesterol biosynthesis, cell cycle regulation and cellular signalling pathways. Phospholipase A2 group IIA (PLA2G2A) mRNA level was subsequently validated as significantly upregulated following SPRY2 KO, highlighting this as a potential mediator downstream of SPRY2. CONCLUSION These findings suggest a role for SPRY2 in glucose and lipid metabolism in hepatocytes and contribute to clarifying the function of this gene in the context of metabolic diseases.
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Affiliation(s)
- Naomi L Cook
- Molecular Epidemiology and Science for Life Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Milos Pjanic
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Andrew G Emmerich
- Molecular Systems Biology, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Abhiram S Rao
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Susanne Hetty
- Molecular Epidemiology and Science for Life Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Joshua W Knowles
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA
- Stanford Diabetes Research Center, Stanford University, Stanford, CA, USA
| | - Thomas Quertermous
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA
- Stanford Diabetes Research Center, Stanford University, Stanford, CA, USA
| | - Casimiro Castillejo-López
- Molecular Epidemiology and Science for Life Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Department of Immunology, Genetics and Pathology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Erik Ingelsson
- Molecular Epidemiology and Science for Life Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA.
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA.
- Stanford Diabetes Research Center, Stanford University, Stanford, CA, USA.
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El Kennani S, Adrait A, Permiakova O, Hesse AM, Ialy-Radio C, Ferro M, Brun V, Cocquet J, Govin J, Pflieger D. Systematic quantitative analysis of H2A and H2B variants by targeted proteomics. Epigenetics Chromatin 2018; 11:2. [PMID: 29329550 PMCID: PMC5767011 DOI: 10.1186/s13072-017-0172-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 12/20/2017] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Histones organize DNA into chromatin through a variety of processes. Among them, a vast diversity of histone variants can be incorporated into chromatin and finely modulate its organization and functionality. Classically, the study of histone variants has largely relied on antibody-based assays. However, antibodies have a limited efficiency to discriminate between highly similar histone variants. RESULTS In this study, we established a mass spectrometry-based analysis to address this challenge. We developed a targeted proteomics method, using selected reaction monitoring or parallel reaction monitoring, to quantify a maximum number of histone variants in a single multiplexed assay, even when histones are present in a crude extract. This strategy was developed on H2A and H2B variants, using 55 peptides corresponding to 25 different histone sequences, among which a few differ by a single amino acid. The methodology was then applied to mouse testis extracts in which almost all histone variants are expressed. It confirmed the abundance profiles of several testis-specific histones during successive stages of spermatogenesis and the existence of predicted H2A.L.1 isoforms. This methodology was also used to explore the over-expression pattern of H2A.L.1 isoforms in a mouse model of male infertility. CONCLUSIONS Our results demonstrate that targeted proteomics is a powerful method to quantify highly similar histone variants and isoforms. The developed method can be easily transposed to the study of human histone variants, whose abundance can be deregulated in various diseases.
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Affiliation(s)
- Sara El Kennani
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Annie Adrait
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Olga Permiakova
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Anne-Marie Hesse
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Côme Ialy-Radio
- INSERM U1016, Institut Cochin, CNRS UMR8104, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Myriam Ferro
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Virginie Brun
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Julie Cocquet
- INSERM U1016, Institut Cochin, CNRS UMR8104, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jérôme Govin
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France.
| | - Delphine Pflieger
- INSERM U1038, CEA, BIG-BGE, Univ. Grenoble Alpes, Grenoble, France. .,CNRS, FR CNRS 3425, Biosciences and Biotechnology Institute of Grenoble, Grenoble, France.
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Tejeda GS, Ayuso-Dolado S, Arbeteta R, Esteban-Ortega GM, Vidaurre OG, Díaz-Guerra M. Brain ischaemia induces shedding of a BDNF-scavenger ectodomain from TrkB receptors by excitotoxicity activation of metalloproteinases and γ-secretases. J Pathol 2016; 238:627-40. [PMID: 26712630 DOI: 10.1002/path.4684] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/02/2015] [Accepted: 12/20/2015] [Indexed: 12/19/2022]
Abstract
Stroke remains a leading cause of death and disability in the world with limited therapies available to restrict brain damage or improve functional recovery after cerebral ischaemia. A promising strategy currently under investigation is the promotion of brain-derived neurotrophic factor (BDNF) signalling through tropomyosin-related kinase B (TrkB) receptors, a pathway essential for neuronal survival and function. However, TrkB and BDNF-signalling are impaired by excitotoxicity, a primary pathological process in stroke also associated with neurodegenerative diseases. Pathological imbalance of TrkB isoforms is critical in neurodegeneration and is caused by calpain processing of BDNF high affinity full-length receptor (TrkB-FL) and an inversion of the transcriptional pattern of the Ntrk2 gene, to favour expression of the truncated isoform TrkB-T1 over TrkB-FL. We report here that both TrkB-FL and neuronal TrkB-T1 also undergo ectodomain shedding by metalloproteinases activated after ischaemic injury or excitotoxic damage of cortical neurons. Subsequently, the remaining membrane-bound C-terminal fragments (CTFs) are cleaved by γ-secretases within the transmembrane region, releasing their intracellular domains (ICDs) into the cytosol. Therefore, we identify TrkB-FL and TrkB-T1 as new substrates of regulated intramembrane proteolysis (RIP), a mechanism that highly contributes to TrkB-T1 regulation in ischaemia but is minor for TrkB-FL which is mainly processed by calpain. However, since the secreted TrkB ectodomain acts as a BDNF scavenger and significantly alters BDNF/TrkB signalling, the mechanism of RIP could contribute to neuronal death in excitotoxicity. These results are highly relevant since they reveal new targets for the rational design of therapies to treat stroke and other pathologies with an excitotoxic component.
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Affiliation(s)
- Gonzalo S Tejeda
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Sara Ayuso-Dolado
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Raquel Arbeteta
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Gema M Esteban-Ortega
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Oscar G Vidaurre
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Margarita Díaz-Guerra
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
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Nelo-Bazán MA, Latorre P, Bolado-Carrancio A, Pérez-Campo FM, Echenique-Robba P, Rodríguez-Rey JC, Carrodeguas JA. Early growth response 1 (EGR-1) is a transcriptional regulator of mitochondrial carrier homolog 1 (MTCH 1)/presenilin 1-associated protein (PSAP). Gene 2015; 578:52-62. [PMID: 26692143 DOI: 10.1016/j.gene.2015.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 11/26/2015] [Accepted: 12/07/2015] [Indexed: 01/25/2023]
Abstract
Attempts to elucidate the cellular function of MTCH1 (mitochondrial carrier homolog 1) have not yet rendered a clear insight into the function of this outer mitochondrial membrane protein. Classical biochemical and cell biology approaches have not produced the expected outcome. In vitro experiments have indicated a likely role in the regulation of cell death by apoptosis, and its reported interaction with presenilin 1 suggests a role in the cellular pathways in which this membrane protease participates, nevertheless in vivo data are missing. In an attempt to identify cellular pathways in which this protein might participate, we have studied its promoter looking for transcriptional regulators. We have identified several putative binding sites for EGR-1 (Early growth response 1; a protein involved in growth, proliferation and differentiation), in the proximal region of the MTCH1 promoter. Chromatin immunoprecipitation showed an enrichment of these sequences in genomic DNA bound to EGR-1 and transient overexpression of EGR-1 in cultured HEK293T cells induces an increase of endogenous MTCH1 levels. We also show that MTCH1 levels increase in response to treatment of cells with doxorubicin, an apoptosis inducer through DNA damage. The endogenous levels of MTCH1 decrease when EGR-1 levels are lowered by RNA interference. Our results indicate that EGR-1 is a transcriptional regulator of MTCH1 and give some clues about the cellular processes in which MTCH1 might participate.
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Affiliation(s)
- María Alejandra Nelo-Bazán
- Institute for Biocomputation and Physics of Complex Systems, University of Zaragoza, Zaragoza, Spain; Department of Biochemistry and Molecular and Cellular Biology, University of Zaragoza, Zaragoza, Spain.
| | - Pedro Latorre
- Institute for Biocomputation and Physics of Complex Systems, University of Zaragoza, Zaragoza, Spain; Department of Animal Production and Food Science and Technology, University of Zaragoza, Spain.
| | | | - Flor M Pérez-Campo
- Department of Internal Medicine, Hospital U. Marqués de Valdecilla-IDIVAL University of Cantabria, 39008 Santander, Cantabria, Spain.
| | - Pablo Echenique-Robba
- Institute for Biocomputation and Physics of Complex Systems, University of Zaragoza, Zaragoza, Spain; Instituto de Química Física Rocasolano, CSIC, Madrid, Spain; Zaragoza Scientific Center for Advanced Modeling (ZCAM), Universidad de Zaragoza, Spain; Departamento de Física Teórica, Universidad de Zaragoza, Spain; Unidad Asociada IQFR-BIFI, Madrid-Zaragoza, Spain.
| | | | - José Alberto Carrodeguas
- Institute for Biocomputation and Physics of Complex Systems, University of Zaragoza, Zaragoza, Spain; Department of Biochemistry and Molecular and Cellular Biology, University of Zaragoza, Zaragoza, Spain; Unidad Asociada IQFR-BIFI, Madrid-Zaragoza, Spain.
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Mikami K, Medová M, Nisa L, Francica P, Glück AA, Tschan MP, Blaukat A, Bladt F, Aebersold DM, Zimmer Y. Impact of p53 Status on Radiosensitization of Tumor Cells by MET Inhibition-Associated Checkpoint Abrogation. Mol Cancer Res 2015; 13:1544-53. [PMID: 26358474 DOI: 10.1158/1541-7786.mcr-15-0022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 08/24/2015] [Indexed: 11/16/2022]
Abstract
UNLABELLED Signaling via the MET receptor tyrosine kinase has been implicated in crosstalk with cellular responses to DNA damage. Our group previously demonstrated that MET inhibition in tumor cells with deregulated MET activity results in radiosensitization via downregulation of the ATR-CHK1-CDC25 pathway, a major signaling cascade responsible for intra-S and G2-M cell-cycle arrest following DNA damage. Here we aimed at studying the potential therapeutic application of ionizing radiation in combination with a MET inhibitor, EMD-1214063, in p53-deficient cancer cells that harbor impaired G1-S checkpoint regulation upon DNA damage. We hypothesized that upon MET inhibition, p53-deficient cells would bypass both G1-S and G2-M checkpoints, promoting premature mitotic entry with substantial DNA lesions and cell death in a greater extent than p53-proficient cells. Our data suggest that p53-deficient cells are more susceptible to EMD-1214063 and combined treatment with irradiation than wild-type p53 lines as inferred from elevated γH2AX expression and increased cytotoxicity. Furthermore, cell-cycle distribution profiling indicates constantly lower G1 and higher G2-M population as well as higher expression of a mitotic marker p-histone H3 following the dual treatment in p53 knockdown isogenic variant, compared with the parental counterpart. IMPLICATIONS The concept of MET inhibition-mediated radiosensitization enhanced by p53 deficiency is of high clinical relevance, as p53 is frequently mutated in numerous types of human cancer. The current data point for a therapeutic advantage for an approach combining MET targeting along with DNA-damaging agents for MET-positive/p53-negative tumors.
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Affiliation(s)
- K Mikami
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland. Department of Clinical Research, University of Bern, Bern, Switzerland
| | - M Medová
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland. Department of Clinical Research, University of Bern, Bern, Switzerland
| | - L Nisa
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland. Department of Clinical Research, University of Bern, Bern, Switzerland
| | - P Francica
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland. Department of Clinical Research, University of Bern, Bern, Switzerland
| | - A A Glück
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland. Department of Clinical Research, University of Bern, Bern, Switzerland
| | - M P Tschan
- Experimental Pathology, Institute of Pathology, University of Bern, Bern, Switzerland
| | - A Blaukat
- Merck Serono Research & Development, Merck KGaA, Darmstadt, Germany
| | - F Bladt
- Merck Serono Research & Development, Merck KGaA, Darmstadt, Germany
| | - D M Aebersold
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland. Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Y Zimmer
- Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland. Department of Clinical Research, University of Bern, Bern, Switzerland.
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