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Tziouvara O, Petsana M, Kourounis D, Papadaki A, Basdra E, Braliou GG, Boleti H. Characterization of the First Secreted Sorting Nexin Identified in the Leishmania Protists. Int J Mol Sci 2024; 25:4095. [PMID: 38612903 PMCID: PMC11012638 DOI: 10.3390/ijms25074095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/19/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024] Open
Abstract
Proteins of the sorting nexin (SNX) family present a modular structural architecture with a phox homology (PX) phosphoinositide (PI)-binding domain and additional PX structural domains, conferring to them a wide variety of vital eukaryotic cell's functions, from signal transduction to membrane deformation and cargo binding. Although SNXs are well studied in human and yeasts, they are poorly investigated in protists. Herein, is presented the characterization of the first SNX identified in Leishmania protozoan parasites encoded by the LdBPK_352470 gene. In silico secondary and tertiary structure prediction revealed a PX domain on the N-terminal half and a Bin/amphiphysin/Rvs (BAR) domain on the C-terminal half of this protein, with these features classifying it in the SNX-BAR subfamily of SNXs. We named the LdBPK_352470.1 gene product LdSNXi, as it is the first SNX identified in Leishmania (L.) donovani. Its expression was confirmed in L. donovani promastigotes under different cell cycle phases, and it was shown to be secreted in the extracellular medium. Using an in vitro lipid binding assay, it was demonstrated that recombinant (r) LdSNXi (rGST-LdSNXi) tagged with glutathione-S-transferase (GST) binds to the PtdIns3P and PtdIns4P PIs. Using a specific a-LdSNXi antibody and immunofluorescence confocal microscopy, the intracellular localization of endogenous LdSNXi was analyzed in L. donovani promastigotes and axenic amastigotes. Additionally, rLdSNXi tagged with enhanced green fluorescent protein (rLdSNXi-EGFP) was heterologously expressed in transfected HeLa cells and its localization was examined. All observed localizations suggest functions compatible with the postulated SNX identity of LdSNXi. Sequence, structure, and evolutionary analysis revealed high homology between LdSNXi and the human SNX2, while the investigation of protein-protein interactions based on STRING (v.11.5) predicted putative molecular partners of LdSNXi in Leishmania.
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Affiliation(s)
- Olympia Tziouvara
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Marina Petsana
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2–4 Papasiopoulou Str., 35131 Lamia, Greece;
| | - Drosos Kourounis
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
| | - Amalia Papadaki
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
| | - Efthimia Basdra
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Georgia G. Braliou
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2–4 Papasiopoulou Str., 35131 Lamia, Greece;
| | - Haralabia Boleti
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
- Bioimaging Unit, Hellenic Pasteur Institute, 11521 Athens, Greece
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Kokkorakis N, Douka K, Nalmpanti A, Politis PK, Zagoraiou L, Matsas R, Gaitanou M. Mirk/Dyrk1B controls ventral spinal cord development via Shh pathway. Cell Mol Life Sci 2024; 81:70. [PMID: 38294527 PMCID: PMC10830675 DOI: 10.1007/s00018-023-05097-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 12/14/2023] [Accepted: 12/17/2023] [Indexed: 02/01/2024]
Abstract
Cross-talk between Mirk/Dyrk1B kinase and Sonic hedgehog (Shh)/Gli pathway affects physiology and pathology. Here, we reveal a novel role for Dyrk1B in regulating ventral progenitor and neuron subtypes in the embryonic chick spinal cord (SC) via the Shh pathway. Using in ovo gain-and-loss-of-function approaches at E2, we report that Dyrk1B affects the proliferation and differentiation of neuronal progenitors at E4 and impacts on apoptosis specifically in the motor neuron (MN) domain. Especially, Dyrk1B overexpression decreases the numbers of ventral progenitors, MNs, and V2a interneurons, while the pharmacological inhibition of endogenous Dyrk1B kinase activity by AZ191 administration increases the numbers of ventral progenitors and MNs. Mechanistically, Dyrk1B overexpression suppresses Shh, Gli2 and Gli3 mRNA levels, while conversely, Shh, Gli2 and Gli3 transcription is increased in the presence of Dyrk1B inhibitor AZ191 or Smoothened agonist SAG. Most importantly, in phenotype rescue experiments, SAG restores the Dyrk1B-mediated dysregulation of ventral progenitors. Further at E6, Dyrk1B affects selectively the medial lateral motor neuron column (LMCm), consistent with the expression of Shh in this region. Collectively, these observations reveal a novel regulatory function of Dyrk1B kinase in suppressing the Shh/Gli pathway and thus affecting ventral subtypes in the developing spinal cord. These data render Dyrk1B a possible therapeutic target for motor neuron diseases.
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Affiliation(s)
- N Kokkorakis
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Hellenic Pasteur Institute, Athens, Greece
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - K Douka
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Hellenic Pasteur Institute, Athens, Greece
| | - A Nalmpanti
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Hellenic Pasteur Institute, Athens, Greece
- Athens International Master's Programme in Neurosciences, Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - P K Politis
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - L Zagoraiou
- School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - R Matsas
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Hellenic Pasteur Institute, Athens, Greece
| | - M Gaitanou
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Hellenic Pasteur Institute, Athens, Greece.
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Avloniti M, Evangelidou M, Gomini M, Loupis T, Emmanouil M, Mitropoulou A, Tselios T, Lassmann H, Gruart A, Delgado-García JM, Probert L, Kyrargyri V. IKKβ deletion from CNS macrophages increases neuronal excitability and accelerates the onset of EAE, while from peripheral macrophages reduces disease severity. J Neuroinflammation 2024; 21:34. [PMID: 38279130 PMCID: PMC10821407 DOI: 10.1186/s12974-024-03023-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 01/15/2024] [Indexed: 01/28/2024] Open
Abstract
BACKGROUND Multiple sclerosis (MS) is a neuroinflammatory demyelinating disease characterized by motor deficits and cognitive decline. Many immune aspects of the disease are understood through studies in the experimental autoimmune encephalomyelitis (EAE) model, including the contribution of the NF-κB transcription factor to neuroinflammation. However, the cell-specific roles of NF-κB to EAE and its cognitive comorbidities still needs further investigation. We have previously shown that the myeloid cell NF-κB plays a role in the healthy brain by exerting homeostatic regulation of neuronal excitability and synaptic plasticity and here we investigated its role in EAE. METHODS We used constitutive MφIKKβΚΟ mice, in which depletion of IKKβ, the main activating kinase of NF-κB, was global to CNS and peripheral macrophages, and ΜgΙΚΚβKO mice, in which depletion was inducible and specific to CNS macrophages by 28 days after tamoxifen administration. We subjected these mice to MOG35-55 induced EAE and cuprizone-induced demyelination. We measured pathology by immunohistochemistry, investigated molecular mechanisms by RNA sequencing analysis and studied neuronal functions by in vivo electrophysiology in awake animals. RESULTS Global depletion of IKKβ from myeloid cells in MφIKKβΚΟ mice accelerated the onset and significantly supressed chronic EAE. Knocking out IKKβ only from CNS resident macrophages accelerated the onset and exacerbated chronic EAE, accompanied by earlier demyelination and immune cell infiltration but had no effect in cuprizone-induced demyelination. Peripheral T cell effector functions were not affected by myeloid cell deletion of IKKβ, but CNS resident mechanisms, such as microglial activation and neuronal hyperexcitability were altered from early in EAE. Lastly, depletion of myeloid cell IKKβ resulted in enhanced late long-term potentiation in EAE. CONCLUSIONS IKKβ-mediated activation of NF-κΒ in myeloid cells has opposing roles in EAE depending on the cell type and the disease stage. In CNS macrophages it is protective while in peripheral macrophages it is disease-promoting and acts mainly during chronic disease. Although clinically protective, CNS myeloid cell IKKβ deletion dysregulates neuronal excitability and synaptic plasticity in EAE. These effects of IKKβ on brain cognitive abilities deserve special consideration when therapeutic interventions that inhibit NF-κB are used in MS.
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Affiliation(s)
- Maria Avloniti
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens, Greece
| | - Maria Evangelidou
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens, Greece
| | - Maria Gomini
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens, Greece
| | - Theodore Loupis
- Greek Genome Centre, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece
- Haematology Research Laboratory, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece
| | - Mary Emmanouil
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens, Greece
| | | | | | - Hans Lassmann
- Department of Neuroimmunology, Centre for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, 41013, Seville, Spain
| | | | - Lesley Probert
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens, Greece
| | - Vasiliki Kyrargyri
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens, Greece.
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Mpekoulis G, Frakolaki E, Taka S, Ioannidis A, Vassiliou AG, Kalliampakou KI, Patas K, Karakasiliotis I, Aidinis V, Chatzipanagiotou S, Angelakis E, Vassilacopoulou D, Vassilaki N. Alteration of L-Dopa decarboxylase expression in SARS-CoV-2 infection and its association with the interferon-inducible ACE2 isoform. PLoS One 2021; 16:e0253458. [PMID: 34185793 PMCID: PMC8241096 DOI: 10.1371/journal.pone.0253458] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 06/06/2021] [Indexed: 02/07/2023] Open
Abstract
L-Dopa decarboxylase (DDC) is the most significantly co-expressed gene with ACE2, which encodes for the SARS-CoV-2 receptor angiotensin-converting enzyme 2 and the interferon-inducible truncated isoform dACE2. Our group previously showed the importance of DDC in viral infections. We hereby aimed to investigate DDC expression in COVID-19 patients and cultured SARS-CoV-2-infected cells, also in association with ACE2 and dACE2. We concurrently evaluated the expression of the viral infection- and interferon-stimulated gene ISG56 and the immune-modulatory, hypoxia-regulated gene EPO. Viral load and mRNA levels of DDC, ACE2, dACE2, ISG56 and EPO were quantified by RT-qPCR in nasopharyngeal swab samples from COVID-19 patients, showing no or mild symptoms, and from non-infected individuals. Samples from influenza-infected patients were analyzed in comparison. SARS-CoV-2-mediated effects in host gene expression were validated in cultured virus-permissive epithelial cells. We found substantially higher gene expression of DDC in COVID-19 patients (7.6-fold; p = 1.2e-13) but not in influenza-infected ones, compared to non-infected subjects. dACE2 was more elevated (2.9-fold; p = 1.02e-16) than ACE2 (1.7-fold; p = 0.0005) in SARS-CoV-2-infected individuals. ISG56 (2.5-fold; p = 3.01e-6) and EPO (2.6-fold; p = 2.1e-13) were also increased. Detected differences were not attributed to enrichment of specific cell populations in nasopharyngeal tissue. While SARS-CoV-2 virus load was positively associated with ACE2 expression (r≥0.8, p<0.001), it negatively correlated with DDC, dACE2 (r≤-0.7, p<0.001) and EPO (r≤-0.5, p<0.05). Moreover, a statistically significant correlation between DDC and dACE2 expression was observed in nasopharyngeal swab and whole blood samples of both COVID-19 and non-infected individuals (r≥0.7). In VeroE6 cells, SARS-CoV-2 negatively affected DDC, ACE2, dACE2 and EPO mRNA levels, and induced cell death, while ISG56 was enhanced at early hours post-infection. Thus, the regulation of DDC, dACE2 and EPO expression in the SARS-CoV-2-infected nasopharyngeal tissue is possibly related with an orchestrated antiviral response of the infected host as the virus suppresses these genes to favor its propagation.
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Affiliation(s)
- George Mpekoulis
- Laboratory of Molecular Virology, Hellenic Pasteur Institute, Athens, Greece
| | - Efseveia Frakolaki
- Laboratory of Molecular Virology, Hellenic Pasteur Institute, Athens, Greece
| | - Styliani Taka
- Allergy and Clinical Immunology Unit, 2nd Pediatric Clinic, National and Kapodistrian University of Athens, Athens, Greece
| | | | - Alice G. Vassiliou
- First Department of Critical Care Medicine & Pulmonary Services, GP Livanos and M Simou Laboratories, National and Kapodistrian University of Athens Medical School, Evangelismos Hospital, Athens, Greece
| | | | - Kostas Patas
- Department of Medical Biopathology, Medical School, University of Athens, Eginition Hospital, Athens, Greece
| | - Ioannis Karakasiliotis
- Laboratory of Biology, Department of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
| | - Vassilis Aidinis
- Institute for Bioinnovation, Biomedical Sciences Research Center “Alexander Fleming”, Athens, Greece
| | - Stylianos Chatzipanagiotou
- Department of Medical Biopathology, Medical School, University of Athens, Eginition Hospital, Athens, Greece
| | - Emmanouil Angelakis
- Department of Diagnostics, Hellenic Pasteur Institute, Athens, Greece
- Aix Marseille Univ, IRD, IHU Méditerranée Infection, VITROME, Marseille, France
| | - Dido Vassilacopoulou
- Section of Biochemistry and Molecular Biology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Niki Vassilaki
- Laboratory of Molecular Virology, Hellenic Pasteur Institute, Athens, Greece
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