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Kumar P, Courtes M, Lemmers C, Le Digarcher A, Coku I, Monteil A, Hong C, Varrault A, Liu R, Wang L, Bouschet T. Functional mapping of microRNA promoters with dCas9 fused to transcriptional regulators. Front Genet 2023; 14:1147222. [PMID: 37214422 PMCID: PMC10196145 DOI: 10.3389/fgene.2023.1147222] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/18/2023] [Indexed: 05/24/2023] Open
Abstract
MicroRNAs are small non-coding RNAs that control gene expression during development, physiology, and disease. Transcription is a key factor in microRNA abundance and tissue-specific expression. Many databases predict the location of microRNA transcription start sites and promoters. However, these candidate regions require functional validation. Here, dCas9 fused to transcriptional activators or repressors - CRISPR activation (CRISPRa) and inhibition (CRISPRi)- were targeted to the candidate promoters of two intronic microRNAs, mmu-miR-335 and hsa-miR-3662, including the promoters of their respective host genes Mest and HBS1L. We report that in mouse embryonic stem cells and brain organoids, miR-335 was downregulated upon CRISPRi of its host gene Mest. Reciprocally, CRISPRa of Mest promoter upregulated miR-335. By contrast, CRISPRa of the predicted miR-335-specific promoter (located in an intron of Mest) did not affect miR-335 levels. Thus, the expression of miR-335 only depends on the promoter activity of its host gene Mest. By contrast, miR-3662 was CRISPR activatable both by the promoter of its host gene HBS1L and an intronic sequence in HEK-293T cells. Thus, CRISPRa and CRISPRi are powerful tools to evaluate the relevance of endogenous regulatory sequences involved in microRNA transcription in defined cell types.
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Affiliation(s)
- Pradeep Kumar
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, United States
- O’Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mathilde Courtes
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Céline Lemmers
- Plateforme de Vectorologie de Montpellier (PVM), BioCampus Montpellier, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Anne Le Digarcher
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Ilda Coku
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Arnaud Monteil
- Plateforme de Vectorologie de Montpellier (PVM), BioCampus Montpellier, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Charles Hong
- Vanderbilt University School of Medicine Nashville, Nashville, TN, United States
| | - Annie Varrault
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Runhua Liu
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, United States
- O’Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Lizhong Wang
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, United States
- O’Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Tristan Bouschet
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
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Impheng H, Lemmers C, Bouasse M, Legros C, Pakaprot N, Guérineau NC, Lory P, Monteil A. The sodium leak channel NALCN regulates cell excitability of pituitary endocrine cells. FASEB J 2021; 35:e21400. [PMID: 33793981 DOI: 10.1096/fj.202000841rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 11/11/2022]
Abstract
Anterior pituitary endocrine cells that release hormones such as growth hormone and prolactin are excitable and fire action potentials. In these cells, several studies previously showed that extracellular sodium (Na+ ) removal resulted in a negative shift of the resting membrane potential (RMP) and a subsequent inhibition of the spontaneous firing of action potentials, suggesting the contribution of a Na+ background conductance. Here, we show that the Na+ leak channel NALCN conducts a Ca2+ - Gd3+ -sensitive and TTX-resistant Na+ background conductance in the GH3 cell line, a cell model of pituitary endocrine cells. NALCN knockdown hyperpolarized the RMP, altered GH3 cell electrical properties and inhibited prolactin secretion. Conversely, the overexpression of NALCN depolarized the RMP, also reshaping the electrical properties of GH3 cells. Overall, our results indicate that NALCN is functional in GH3 cells and involved in endocrine cell excitability as well as in hormone secretion. Indeed, the GH3 cell line suitably models native pituitary cells that display a similar Na+ background conductance and appears as a proper cellular model to study the role of NALCN in cellular excitability.
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Affiliation(s)
- Hathaichanok Impheng
- IGF, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Céline Lemmers
- IGF, Université de Montpellier, CNRS, INSERM, Montpellier, France.,PVM, BCM, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Malik Bouasse
- IGF, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Christian Legros
- MITOVASC Institute, UMR CNRS 6015 - UMR INSERM U1083, Université d'Angers, Angers, France
| | - Narawut Pakaprot
- Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nathalie C Guérineau
- IGF, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Philippe Lory
- IGF, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Arnaud Monteil
- IGF, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, France.,PVM, BCM, Université de Montpellier, CNRS, INSERM, Montpellier, France
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Guo Y, Gabola M, Lattanzio R, Paul C, Pinet V, Tang R, Turali H, Bremond J, Longobardi C, Maurizy C, Da Costa Q, Finetti P, Boissière-Michot F, Rivière B, Lemmers C, Garnier S, Bertucci F, Zlobec I, Chebli K, Tazi J, Azar R, Blanchard JM, Sicinski P, Mamessier E, Lemmers B, Hahne M. Cyclin A2 maintains colon homeostasis and is a prognostic factor in colorectal cancer. J Clin Invest 2021; 131:131517. [PMID: 33332285 DOI: 10.1172/jci131517] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 12/09/2020] [Indexed: 12/19/2022] Open
Abstract
To clarify the function of cyclin A2 in colon homeostasis and colorectal cancer (CRC), we generated mice deficient for cyclin A2 in colonic epithelial cells (CECs). Colons of these mice displayed architectural changes in the mucosa and signs of inflammation, as well as increased proliferation of CECs associated with the appearance of low- and high-grade dysplasias. The main initial events triggering those alterations in cyclin A2-deficient CECs appeared to be abnormal mitoses and DNA damage. Cyclin A2 deletion in CECs promoted the development of dysplasia and adenocarcinomas in a murine colitis-associated cancer model. We next explored the status of cyclin A2 expression in clinical CRC samples at the mRNA and protein levels and found higher expression in tumors of patients with stage 1 or 2 CRC compared with those of patients with stage 3 or 4 CRC. A meta-analysis of 11 transcriptome data sets comprising 2239 primary CRC tumors revealed different expression levels of CCNA2 (the mRNA coding for cyclin A2) among the CRC tumor subtypes, with the highest expression detected in consensus molecular subtype 1 (CMS1) and the lowest in CMS4 tumors. Moreover, we found high expression of CCNA2 to be a new, independent prognosis factor for CRC tumors.
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Affiliation(s)
- Yuchen Guo
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Monica Gabola
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Rossano Lattanzio
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University, Chieti, Italy.,Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy
| | - Conception Paul
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Valérie Pinet
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Ruizhi Tang
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Hulya Turali
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Julie Bremond
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Ciro Longobardi
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Chloé Maurizy
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Quentin Da Costa
- Predictive Oncology Laboratory, Cancer Research Center of Marseille (CRCM), INSERM, U1068, CNRS, UMR7258, Institut Paoli-Calmettes, Aix Marseille Université, Marseille, France
| | - Pascal Finetti
- Predictive Oncology Laboratory, Cancer Research Center of Marseille (CRCM), INSERM, U1068, CNRS, UMR7258, Institut Paoli-Calmettes, Aix Marseille Université, Marseille, France
| | - Florence Boissière-Michot
- Translationnal Research Unit, Montpellier Cancer Institute, Montpellier, France - Université de Montpellier, Montpellier, France
| | - Benjamin Rivière
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Céline Lemmers
- PVM, Biocampus, Université de Montpellier, CNRS, Montpellier, France
| | - Séverine Garnier
- Predictive Oncology Laboratory, Cancer Research Center of Marseille (CRCM), INSERM, U1068, CNRS, UMR7258, Institut Paoli-Calmettes, Aix Marseille Université, Marseille, France
| | - François Bertucci
- Predictive Oncology Laboratory, Cancer Research Center of Marseille (CRCM), INSERM, U1068, CNRS, UMR7258, Institut Paoli-Calmettes, Aix Marseille Université, Marseille, France.,Department of Medical Oncology, Institut Paoli-Calmettes, Marseille, France
| | - Inti Zlobec
- Institute of Pathology, University of Bern, Bern, Switzerland
| | - Karim Chebli
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Jamal Tazi
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Rania Azar
- Faculty of Pharmacy, Lebanese University, Hadath, Lebanon
| | - Jean-Marie Blanchard
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | | | - Emilie Mamessier
- Predictive Oncology Laboratory, Cancer Research Center of Marseille (CRCM), INSERM, U1068, CNRS, UMR7258, Institut Paoli-Calmettes, Aix Marseille Université, Marseille, France
| | - Bénédicte Lemmers
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Michael Hahne
- Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
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Monteil A, Chausson P, Boutourlinsky K, Mezghrani A, Huc-Brandt S, Blesneac I, Bidaud I, Lemmers C, Leresche N, Lambert RC, Lory P. Inhibition of Cav3.2 T-type Calcium Channels by Its Intracellular I-II Loop. J Biol Chem 2015; 290:16168-76. [PMID: 25931121 DOI: 10.1074/jbc.m114.634261] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Indexed: 11/06/2022] Open
Abstract
Voltage-dependent calcium channels (Cav) of the T-type family (Cav3.1, Cav3.2, and Cav3.3) are activated by low threshold membrane depolarization and contribute greatly to neuronal network excitability. Enhanced T-type channel activity, especially Cav3.2, contributes to disease states, including absence epilepsy. Interestingly, the intracellular loop connecting domains I and II (I-II loop) of Cav3.2 channels is implicated in the control of both surface expression and channel gating, indicating that this I-II loop plays an important regulatory role in T-type current. Here we describe that co-expression of this I-II loop or its proximal region (Δ1-Cav3.2; Ser(423)-Pro(542)) together with recombinant full-length Cav3.2 channel inhibited T-type current without affecting channel expression and membrane incorporation. Similar T-type current inhibition was obtained in NG 108-15 neuroblastoma cells that constitutively express Cav3.2 channels. Of interest, Δ1-Cav3.2 inhibited both Cav3.2 and Cav3.1 but not Cav3.3 currents. Efficacy of Δ1-Cav3.2 to inhibit native T-type channels was assessed in thalamic neurons using viral transduction. We describe that T-type current was significantly inhibited in the ventrobasal neurons that express Cav3.1, whereas in nucleus reticularis thalami neurons that express Cav3.2 and Cav3.3 channels, only the fast inactivating T-type current (Cav3.2 component) was significantly inhibited. Altogether, these data describe a new strategy to differentially inhibit Cav3 isoforms of the T-type calcium channels.
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Affiliation(s)
- Arnaud Monteil
- From the Université de Montpellier, CNRS UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Montpellier, F-34094 France, INSERM, U1191, Montpellier, F-34094 France, Plateforme de Vectorologie, Biocampus Montpellier CNRS UMS 3426, INSERM US009, Montpellier, F-34094 France, LabEx "Ion Channel Science and Therapeutics," Montpellier, F-34094 France
| | - Patrick Chausson
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, UM 119, Neuroscience Paris Seine (NPS), Paris F-75005, France, CNRS UMR 8246, NPS, Paris F-75005, France, and INSERM, U1130, NPS, Paris F-75005, France
| | - Katia Boutourlinsky
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, UM 119, Neuroscience Paris Seine (NPS), Paris F-75005, France, CNRS UMR 8246, NPS, Paris F-75005, France, and INSERM, U1130, NPS, Paris F-75005, France
| | - Alexandre Mezghrani
- From the Université de Montpellier, CNRS UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Montpellier, F-34094 France, INSERM, U1191, Montpellier, F-34094 France, LabEx "Ion Channel Science and Therapeutics," Montpellier, F-34094 France
| | - Sylvaine Huc-Brandt
- From the Université de Montpellier, CNRS UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Montpellier, F-34094 France, INSERM, U1191, Montpellier, F-34094 France, LabEx "Ion Channel Science and Therapeutics," Montpellier, F-34094 France
| | - Iulia Blesneac
- From the Université de Montpellier, CNRS UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Montpellier, F-34094 France, INSERM, U1191, Montpellier, F-34094 France, LabEx "Ion Channel Science and Therapeutics," Montpellier, F-34094 France
| | - Isabelle Bidaud
- From the Université de Montpellier, CNRS UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Montpellier, F-34094 France, INSERM, U1191, Montpellier, F-34094 France, LabEx "Ion Channel Science and Therapeutics," Montpellier, F-34094 France
| | - Céline Lemmers
- From the Université de Montpellier, CNRS UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Montpellier, F-34094 France, INSERM, U1191, Montpellier, F-34094 France, Plateforme de Vectorologie, Biocampus Montpellier CNRS UMS 3426, INSERM US009, Montpellier, F-34094 France, LabEx "Ion Channel Science and Therapeutics," Montpellier, F-34094 France
| | - Nathalie Leresche
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, UM 119, Neuroscience Paris Seine (NPS), Paris F-75005, France, CNRS UMR 8246, NPS, Paris F-75005, France, and INSERM, U1130, NPS, Paris F-75005, France
| | - Régis C Lambert
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, UM 119, Neuroscience Paris Seine (NPS), Paris F-75005, France, CNRS UMR 8246, NPS, Paris F-75005, France, and INSERM, U1130, NPS, Paris F-75005, France
| | - Philippe Lory
- From the Université de Montpellier, CNRS UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Montpellier, F-34094 France, INSERM, U1191, Montpellier, F-34094 France, LabEx "Ion Channel Science and Therapeutics," Montpellier, F-34094 France,
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Baratin M, Roetynck S, Pouvelle B, Lemmers C, Viebig NK, Johansson S, Bierling P, Scherf A, Gysin J, Vivier E, Ugolini S. Dissection of the role of PfEMP1 and ICAM-1 in the sensing of Plasmodium-falciparum-infected erythrocytes by natural killer cells. PLoS One 2007; 2:e228. [PMID: 17311092 PMCID: PMC1794133 DOI: 10.1371/journal.pone.0000228] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Accepted: 01/25/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Host innate immunity contributes to malaria clinical outcome by providing protective inflammatory cytokines such as interferon-gamma, and by shaping the adaptive immune response. Plasmodium falciparum (Pf) is the etiologic agent of the most severe forms of human malaria. Natural Killer (NK) cells are lymphocytes of the innate immune system that are the first effectors to produce interferon-gamma in response to Pf. However, the molecular bases of Pf-NK cell recognition events are unknown. Our study focuses on the role of Pf erythrocyte membrane protein 1 (PfEMP1), a major Pf virulence factor. PfEMP1 is expressed on parasitized-erythrocytes and participates to vascular obstruction through the binding to several host receptors. PfEMP1 is also a pivotal target for host antibody response to Pf infection. METHODOLOGY/PRINCIPAL FINDINGS Using genetically-engineered parasite mutant strains, a human genetic deficiency, and blocking antibodies, we identified two receptor-ligand pairs involved in two uncoupled events occurring during the sensing of Pf infection by NK cells. First, PfEMP1 interaction with one of its host receptor, chondroitin sulfate A, mediates the cytoadhesion of Pf-infected erythrocytes to human NK cell lines, but is not required for primary NK cell activation. Second, intercellular adhesion molecule-1 (ICAM-1), another host receptor for PfEMP1, is mandatory for NK cell interferon-gamma response. In this case, ICAM-1 acts via its engagement with its host ligand, LFA-1, and not with PfEMP1, consistent with the obligatory cross-talk of NK cells with macrophages for their production of interferon-gamma. CONCLUSION/SIGNIFICANCE PfEMP1-independent but ICAM-1/LFA-1-dependent events occurring during NK cell activation by Pf highlight the fundamental role of cellular cooperation during innate immune response to malaria.
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Affiliation(s)
- Myriam Baratin
- Aix-Marseille Université, Faculté des Sciences de Luminy, Centre d'Immunologie de Marseille-Luminy (CIML), Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U631, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR6102, Marseille, France
| | - Sophie Roetynck
- Aix-Marseille Université, Faculté des Sciences de Luminy, Centre d'Immunologie de Marseille-Luminy (CIML), Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U631, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR6102, Marseille, France
| | - Bruno Pouvelle
- Unité de Parasitologie Expérimentale, Université de la Méditerranée, Marseille, France
| | - Céline Lemmers
- Aix-Marseille Université, Faculté des Sciences de Luminy, Centre d'Immunologie de Marseille-Luminy (CIML), Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U631, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR6102, Marseille, France
| | - Nicola K. Viebig
- Institut Pasteur and Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Sofia Johansson
- Aix-Marseille Université, Faculté des Sciences de Luminy, Centre d'Immunologie de Marseille-Luminy (CIML), Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U631, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR6102, Marseille, France
| | | | - Artur Scherf
- Institut Pasteur and Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Jürg Gysin
- Unité de Parasitologie Expérimentale, Université de la Méditerranée, Marseille, France
| | - Eric Vivier
- Aix-Marseille Université, Faculté des Sciences de Luminy, Centre d'Immunologie de Marseille-Luminy (CIML), Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U631, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR6102, Marseille, France
- Hôpital de la Conception, Assistance Publique – Hôpitaux de Marseille, France
- * To whom correspondence should be addressed. E-mail: (SU); (EV)
| | - Sophie Ugolini
- Aix-Marseille Université, Faculté des Sciences de Luminy, Centre d'Immunologie de Marseille-Luminy (CIML), Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U631, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR6102, Marseille, France
- * To whom correspondence should be addressed. E-mail: (SU); (EV)
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Abstract
Malaria, caused by the infection with parasites of the germs Plasmodium, is one of the three most important infectious diseases worldwide, along with tuberculosis and infection with human immunodeficiency virus. Natural killer (NK) cells are lymphocytes classically involved in the early defense against viral infections and intracytoplasmic bacterial infections and are also implicated during the course of tumor development and allogeneic transplantation. These cells display important cytotoxic activity and produce high levels of proinflammatory cytokines. In both mouse and human models of malaria, NK cells appear to be a major source of interferon-gamma during the early phase of infection. In humans, indirect signaling through monocytes/macrophages required to optimally stimulate NK cell activity. However, the in vivo functions of NK cells during malaria are still enigmatic, and many issues remain to be dissected, such as the molecular basis of the direct recognition of iRBCs by NK cells.
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Affiliation(s)
- Sophie Roetynck
- Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Marseille, France
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7
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Pilot F, Philippe JM, Lemmers C, Lecuit T. Spatial control of actin organization at adherens junctions by a synaptotagmin-like protein Btsz. Nature 2006; 442:580-4. [PMID: 16862128 DOI: 10.1038/nature04935] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 05/16/2006] [Indexed: 11/09/2022]
Abstract
Epithelial tissues maintain a robust architecture during development. This fundamental property relies on intercellular adhesion through the formation of adherens junctions containing E-cadherin molecules. Localization of E-cadherin is stabilized through a pathway involving the recruitment of actin filaments by E-cadherin. Here we identify an additional pathway that organizes actin filaments in the apical junctional region (AJR) where adherens junctions form in embryonic epithelia. This pathway is controlled by Bitesize (Btsz), a synaptotagmin-like protein that is recruited in the AJR independently of E-cadherin and is required for epithelial stability in Drosophila embryos. On loss of btsz, E-cadherin is recruited normally to the AJR, but is not stabilized properly and actin filaments fail to form a stable continuous network. In the absence of E-cadherin, actin filaments are stable for a longer time than they are in btsz mutants. We identify two polarized cues that localize Btsz: phosphatidylinositol (4,5)-bisphosphate, to which Btsz binds; and Par-3. We show that Btsz binds to the Ezrin-Radixin-Moesin protein Moesin, an F-actin-binding protein that is localized apically and is recruited in the AJR in a btsz-dependent manner. Expression of a dominant-negative form of Ezrin that does not bind F-actin phenocopies the loss of btsz. Thus, our data indicate that, through their interaction, Btsz and Moesin may mediate the proper organization of actin in a local domain, which in turn stabilizes E-cadherin. These results provide a mechanism for the spatial order of actin organization underlying junction stabilization in primary embryonic epithelia.
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Affiliation(s)
- Fanny Pilot
- Institut de Biologie du Développement de Marseille Luminy (IBDML) UMR 6216, CNRS-Université de la Méditerrannée. Campus de Luminy, case 907, 13288 Marseille cedex 09, France
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Pilot F, Philippe JM, Lemmers C, Chauvin JP, Lecuit T. Developmental control of nuclear morphogenesis and anchoring by charleston, identified in a functional genomic screen of Drosophila cellularisation. Development 2006; 133:711-23. [PMID: 16421189 DOI: 10.1242/dev.02251] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Morphogenesis of epithelial tissues relies on the precise developmental control of cell polarity and architecture. In the early Drosophila embryo, the primary epithelium forms during cellularisation, following a tightly controlled genetic programme where specific sets of genes are upregulated. Some of them, for example, control membrane invagination between the nuclei anchored at the apical surface of the syncytium. We used microarrays to describe the global programme of gene expression underlying cellularisation and identified distinct classes of upregulated genes during this process. Fifty-seven genes were then tested functionally by RNAi. We found six genes affecting various aspects of cellular architecture: membrane growth, organelle transport or organisation and junction assembly. We focus here on charleston (char), a new regulator of nuclear morphogenesis and of apical nuclear anchoring. In char-depleted embryos, the nuclei fail to maintain their elongated shape and, instead, become rounded. In addition, together with a disruption of the centrosome-nuclear envelope interaction, the nuclei lose their regular apical anchoring. These nuclear defects perturb the regular columnar organisation of epithelial cells in the embryo. Although microtubules are required for both nuclear morphogenesis and anchoring, char does not control microtubule organisation and association to the nuclear envelope. We show that Char is lipid anchored at the nuclear envelope by a farnesylation group, and localises at the inner nuclear membrane together with Lamin. Our data suggest that Char forms a scaffold that regulates nuclear architecture to constrain nuclei in tight columnar epithelial cells. The upregulation of Char during cellularisation and gastrulation reveals the existence of an as yet unknown developmental control of nuclear morphology and anchoring in embryonic epithelia.
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Affiliation(s)
- Fanny Pilot
- Institut de Biologie du Développement de Marseille (IBDM de Génétique et de Physiologie du Développement (LGPD), UMR6545 CNRS-Université de la Méditerrannée. Campus de Luminy case 907, Marseille 13288 cedex9, France
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Lemmers C, Médina E, Lane-Guermonprez L, Arsanto JP, Le Bivic A. Rôle des protéines Crumbs dans le contrôle de la morphogenèse des cellules épithéliales et des photorécepteurs. Med Sci (Paris) 2004; 20:663-7. [PMID: 15329816 DOI: 10.1051/medsci/2004206-7663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Degeneration of retina can have many causes and among the genes involved, CRB1 has been shown to be associated with Retinitis pigmentosa (RP) group 12 and Leber congenital amaurosis (LCA), two dramatic pathologies in young patients. CRB1 belongs to a family of genes conserved from Caenorhabditis elegans to human. In Drosophila melanogaster, for example, crb is essential both for the formation of the adherens junctions in epithelial cells of ectodermal origin during gastrulation and for the morphogenesis of photoreceptors in the eye. Crumbs is a transmembrane protein with a short cytoplasmic domain that interacts with scaffold proteins, Stardust and Discs lost, and with the apical cytoskeleton made of moesin and betaheavy-spectrin. The extracellular domain of Crumbs is essential for its function in photoreceptors but so far there are no known proteins interacting with it. In human, there are three known crb homologues, CRB1, 2 and 3, and CRB1 is expressed in the retina and localizes to the adherens junctions of the rods. Based on the model drawn from Drosophila, CRB1 could be involved in maintaining the morphology of rods to ensure a normal function of the retina. This is supported by the fact that the homologues of the known partners of Crumbs are also conserved in human and expressed in the retina. Understanding the precise molecular mechanism by which CRB1 acts will help to find new therapies for patients suffering from RP12 and LCA.
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Affiliation(s)
- Céline Lemmers
- UMR 6156, Laboratoire de neurogenèse et morphogenèse au cours du développement et chez l'adulte (NMDA), IBDM, Campus de Luminy, Case 907. 13288 Marseille Cedex 09. France
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Lemmers C, Michel D, Lane-Guermonprez L, Delgrossi MH, Médina E, Arsanto JP, Le Bivic A. CRB3 binds directly to Par6 and regulates the morphogenesis of the tight junctions in mammalian epithelial cells. Mol Biol Cell 2004; 15:1324-33. [PMID: 14718572 PMCID: PMC363137 DOI: 10.1091/mbc.e03-04-0235] [Citation(s) in RCA: 231] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Crumbs is an apical transmembrane protein crucial for epithelial morphogenesis in Drosophila melanogaster embryos. A protein with all the characteristics for a Crumbs homologue has been identified from patients suffering from retinitis pigmentosa group 12, but this protein (CRB1) is only expressed in retina and some parts of the brain, both in human and mouse. Here, we describe CRB3, another Crumbs homologue that is preferentially expressed in epithelial tissues and skeletal muscles in human. CRB3 shares the conserved cytoplasmic domain with other Crumbs but exhibits a very short extracellular domain without the EGF- and laminin A-like G repeats present in the other Crumbs. CRB3 is localized to the apical and subapical area of epithelial cells from the mouse and human intestine, suggesting that it could play a role in epithelial morphogenesis. Indeed, expression of CRB3 or of a chimera containing the extracellular domain of the neurotrophin receptor p75NTR and the transmembrane and cytoplasmic domains of CRB3 led to a slower development of functional tight junctions in Madin-Darby canine kidney cells. This phenotype relied on the presence of CRB3 four last amino acids (ERLI) that are involved in a direct interaction with Par6, a regulator of epithelial polarity and tight junction formation. Thus, CRB3, through its cytoplasmic domain and its interactors, plays a role in apical membrane morphogenesis and tight junction regulation.
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Affiliation(s)
- Céline Lemmers
- Laboratoire de Neurogenèse et Morphogenèse au cours du Développement et chez l'Adulte, Unité Mixte Recherche 6156 Centre National de la Recherche Scientifique, Université de la Méditerranée, Marseille, France
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Médina E, Lemmers C, Lane-Guermonprez L, Le Bivic A. Role of the Crumbs complex in the regulation of junction formation in Drosophila and mammalian epithelial cells. Biol Cell 2002; 94:305-13. [PMID: 12500938 DOI: 10.1016/s0248-4900(02)00004-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The formation of a belt-like junctional complex separating the apical from the lateral domain is an essential step in the differentiation of epithelial cells. Thus protein complexes regulating this event are of first importance for the development of cell polarity and physiological functions of epithelial tissues. In Drosophila, the discovery of a gene, crb, controlling the coalescence of the spots of zonula adherens (ZA) into a adhesive ring around the cells was a major step. We know now that Crumbs, the product of crb is an apical transmembrane protein conserved in mammals and that it interacts by its cytoplasmic domain with two cortical modular proteins, Stardust (Sdt) and Discs lost (Dlt) that are also essential for the correct assembly of the ZA. These two proteins are also conserved in mammals and it is most likely that the Crumbs complex plays a similar role in very different species. Recently, we have shown that Crumbs interacts with the cortical cytoskeleton made of DMoesin and beta heavy-Spectrin and this connection could explain in part the role of Crumbs in building the ZA. Future work will help to understand several aspects of the Crumbs complex that are still unknown, like the role of the large extracellular domain or the precise function of Sdt and Dlt in the building of the ZA. Finding an answer to these questions will help to find new therapies for Retinitis pigmentosa and other retina degeneration in which CRB1, the human homologue of crb, has been involved.
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Affiliation(s)
- Emmanuelle Médina
- NMDA-IBDM, UMR 6156, Campus de Luminy, Université de la Méditerranée, case 907, 13288 Marseille cedex 09, France
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Lemmers C, Médina E, Delgrossi MH, Michel D, Arsanto JP, Le Bivic A. hINADl/PATJ, a homolog of discs lost, interacts with crumbs and localizes to tight junctions in human epithelial cells. J Biol Chem 2002; 277:25408-15. [PMID: 11964389 DOI: 10.1074/jbc.m202196200] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
dCrumbs is an apical organizer crucial for the maintenance of epithelial polarity in Drosophila (1). It is known that dCrumbs interacts with Discs lost (Dlt), a protein with four PDZ (PSD95/Discs Large/ZO-1) domains (2), and Stardust (Sdt), a protein of the MAGUK (membrane-associated guanylate kinase) family (3, 4). We have searched for potential homologs of Dlt in human epithelial cells and characterized one of them in intestinal epithelial cells. Human INAD-like (hINADl) contains 8 PDZ domains, is concentrated in tight junctions, and is also found at the apical plasma membrane. Overexpression of hINADl disrupted the tight junctions localization of ZO-1 and 3. We also identified a partial cDNA coding the transmembrane and cytoplasmic domains of a new human crumbs (CRB3) expressed in Caco-2 cells. This CRB3 was able to interact through its C-terminal end with the N-terminal domain of hINADl. Taken together, the data indicate that hINADl is likely to represent a Dlt homolog in mammalian epithelial cells and might be involved in regulating the integrity of tight junctions. We thus propose to rename hINADl PATJ for protein associated to tight junctions.
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Affiliation(s)
- Céline Lemmers
- Laboratoire de Neurogenèse et Morphogenèse du Développement à l'Adulte (NMDA, Unité Mixte de Recherche 6165), Institut de Biologie du Développement de Marseille, Faculté des Sciences de Luminy, Université de la Méditerranée, France
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