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Saha O, Melo de Farias AR, Pelletier A, Siedlecki-Wullich D, Landeira BS, Gadaut J, Carrier A, Vreulx AC, Guyot K, Shen Y, Bonnefond A, Amouyel P, Tcw J, Kilinc D, Queiroz CM, Delahaye F, Lambert JC, Costa MR. The Alzheimer's disease risk gene BIN1 regulates activity-dependent gene expression in human-induced glutamatergic neurons. Mol Psychiatry 2024:10.1038/s41380-024-02502-y. [PMID: 38514804 DOI: 10.1038/s41380-024-02502-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/23/2024]
Abstract
Bridging Integrator 1 (BIN1) is the second most important Alzheimer's disease (AD) risk gene, but its physiological roles in neurons and its contribution to brain pathology remain largely elusive. In this work, we show that BIN1 plays a critical role in the regulation of calcium homeostasis, electrical activity, and gene expression of glutamatergic neurons. Using single-cell RNA-sequencing on cerebral organoids generated from isogenic BIN1 wild type (WT), heterozygous (HET) and homozygous knockout (KO) human-induced pluripotent stem cells (hiPSCs), we show that BIN1 is mainly expressed by oligodendrocytes and glutamatergic neurons, like in the human brain. Both BIN1 HET and KO cerebral organoids show specific transcriptional alterations, mainly associated with ion transport and synapses in glutamatergic neurons. We then demonstrate that BIN1 cell-autonomously regulates gene expression in glutamatergic neurons by using a novel protocol to generate pure culture of hiPSC-derived induced neurons (hiNs). Using this system, we also show that BIN1 plays a key role in the regulation of neuronal calcium transients and electrical activity via its interaction with the L-type voltage-gated calcium channel Cav1.2. BIN1 KO hiNs show reduced activity-dependent internalization and higher Cav1.2 expression compared to WT hiNs. Pharmacological blocking of this channel with clinically relevant doses of nifedipine, a calcium channel blocker, partly rescues electrical and gene expression alterations in BIN1 KO glutamatergic neurons. Further, we show that transcriptional alterations in BIN1 KO hiNs that affect biological processes related to calcium homeostasis are also present in glutamatergic neurons of the human brain at late stages of AD pathology. Together, these findings suggest that BIN1-dependent alterations in neuronal properties could contribute to AD pathophysiology and that treatment with low doses of clinically approved calcium blockers should be considered as an option to slow disease-onset and progression.
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Affiliation(s)
- Orthis Saha
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Ana Raquel Melo de Farias
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
- Brain Institute, Federal University of Rio Grande do Norte, Av. Senador Salgado Filho, 3000, Campus Universitário, Lagoa, Nova, 59078-970, Natal, Brazil
| | - Alexandre Pelletier
- Univ. Lille, Inserm, CNRS, CHU Lille, Institut Pasteur de Lille, U1283-UMR 8199 EGID, Pôle Recherche, 1 Place de Verdun, 59045, Lille, Cedex, France
- Department of Pharmacology, Physiology & Biophysics, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
| | - Dolores Siedlecki-Wullich
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Bruna Soares Landeira
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Johanna Gadaut
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Arnaud Carrier
- Univ. Lille, Inserm, CNRS, CHU Lille, Institut Pasteur de Lille, U1283-UMR 8199 EGID, Pôle Recherche, 1 Place de Verdun, 59045, Lille, Cedex, France
| | - Anaïs-Camille Vreulx
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Karine Guyot
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Yun Shen
- Department of Pharmacology, Physiology & Biophysics, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
| | - Amelie Bonnefond
- Univ. Lille, Inserm, CNRS, CHU Lille, Institut Pasteur de Lille, U1283-UMR 8199 EGID, Pôle Recherche, 1 Place de Verdun, 59045, Lille, Cedex, France
| | - Philippe Amouyel
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Julia Tcw
- Department of Pharmacology, Physiology & Biophysics, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
- Bioinformatics Program, Faculty of Computing & Data Sciences, Boston University, Boston, MA, 02115, USA
| | - Devrim Kilinc
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Claudio Marcos Queiroz
- Brain Institute, Federal University of Rio Grande do Norte, Av. Senador Salgado Filho, 3000, Campus Universitário, Lagoa, Nova, 59078-970, Natal, Brazil
| | - Fabien Delahaye
- Univ. Lille, Inserm, CNRS, CHU Lille, Institut Pasteur de Lille, U1283-UMR 8199 EGID, Pôle Recherche, 1 Place de Verdun, 59045, Lille, Cedex, France
| | - Jean-Charles Lambert
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France
| | - Marcos R Costa
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, DISTALZ, 1 rue du Professeur Calmette, 59019, Lille, France.
- Brain Institute, Federal University of Rio Grande do Norte, Av. Senador Salgado Filho, 3000, Campus Universitário, Lagoa, Nova, 59078-970, Natal, Brazil.
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2
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Orsolic I, Carrier A, Esteller M. Genetic and epigenetic defects of the RNA modification machinery in cancer. Trends Genet 2023; 39:74-88. [PMID: 36379743 DOI: 10.1016/j.tig.2022.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [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: 06/28/2022] [Revised: 09/25/2022] [Accepted: 10/26/2022] [Indexed: 11/13/2022]
Abstract
Cancer was initially considered to be an exclusively genetic disease, but an interplay of dysregulated genetic and epigenetic mechanisms is now known to contribute to the cancer phenotype. More recently, chemical modifications of RNA molecules - the so-called epitranscriptome - have been found to regulate various aspects of RNA function and homeostasis. Specific enzymes, known as RNA-modifying proteins (RMPs), are responsible for depositing, removing, and reading chemical modifications in RNA. Intensive investigations in the epitranscriptomic field in recent years, in conjunction with great technological advances, have revealed the critical role of RNA modifications in regulating numerous cellular pathways. Furthermore, growing evidence has revealed that RNA modification machinery is often altered in human cancers, highlighting the enormous potential of RMPs as pharmacological targets or diagnostic markers.
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Affiliation(s)
- Ines Orsolic
- Josep Carreras Leukemia Research Institute (IJC), Badalona, Barcelona, Catalonia, Spain
| | - Arnaud Carrier
- Josep Carreras Leukemia Research Institute (IJC), Badalona, Barcelona, Catalonia, Spain
| | - Manel Esteller
- Josep Carreras Leukemia Research Institute (IJC), Badalona, Barcelona, Catalonia, Spain; Centro de Investigacion Biomedica en Red Cancer (CIBERONC), 28029 Madrid, Spain; Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain; Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), Barcelona, Catalonia, Spain.
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3
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Carrier A, Desjobert C, Lobjois V, Rigal L, Busato F, Tost J, Ensenyat-Mendez M, Marzese DM, Pradines A, Favre G, Lamant L, Lanfrancone L, Etievant C, Arimondo PB, Riond J. Epigenetically regulated PCDHB15 impairs aggressiveness of metastatic melanoma cells. Clin Epigenetics 2022; 14:156. [PMID: 36443814 PMCID: PMC9707039 DOI: 10.1186/s13148-022-01364-x] [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: 06/06/2022] [Accepted: 10/25/2022] [Indexed: 11/29/2022] Open
Abstract
The protocadherin proteins are cell adhesion molecules at the crossroad of signaling pathways playing a major role in neuronal development. It is now understood that their role as signaling hubs is not only important for the normal physiology of cells but also for the regulation of hallmarks of cancerogenesis. Importantly, protocadherins form a cluster of genes that are regulated by DNA methylation. We have identified for the first time that PCDHB15 gene is DNA-hypermethylated on its unique exon in the metastatic melanoma-derived cell lines and patients' metastases compared to primary tumors. This DNA hypermethylation silences the gene, and treatment with the DNA demethylating agent 5-aza-2'-deoxycytidine reinduces its expression. We explored the role of PCDHB15 in melanoma aggressiveness and showed that overexpression impairs invasiveness and aggregation of metastatic melanoma cells in vitro and formation of lung metastasis in vivo. These findings highlight important modifications of the methylation of the PCDHβ genes in melanoma and support a functional role of PCDHB15 silencing in melanoma aggressiveness.
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Affiliation(s)
- Arnaud Carrier
- Unité de Service et de Recherche USR n°3388 CNRS-Pierre Fabre, Epigenetic Targeting of Cancer (ETaC), Toulouse, France ,Cancer Epigenetics Group, Institut de Recerca Contra la Leucèmia Josep Carreras, Barcelona, Spain
| | - Cécile Desjobert
- Unité de Service et de Recherche USR n°3388 CNRS-Pierre Fabre, Epigenetic Targeting of Cancer (ETaC), Toulouse, France
| | - Valérie Lobjois
- grid.508721.9Institut des Technologies Avancées en Sciences du Vivant – ITAV-USR3505, CNRS, Université de Toulouse, Université Paul Sabatier-UT3, Toulouse, France ,grid.15781.3a0000 0001 0723 035XLaboratoire de Biologie Cellulaire et Moléculaire du Contrôle de la Prolifération, CNRS UMR 5088, Université Paul Sabatier-UT3, Toulouse, France
| | - Lise Rigal
- grid.508721.9Institut des Technologies Avancées en Sciences du Vivant – ITAV-USR3505, CNRS, Université de Toulouse, Université Paul Sabatier-UT3, Toulouse, France
| | - Florence Busato
- grid.460789.40000 0004 4910 6535Laboratory for Epigenetics and Environment, Centre National de Recherche en Génomique Humain, CEA-Institut de Biologie Francois Jacob, Université Paris-Saclay, Evry, France
| | - Jörg Tost
- grid.460789.40000 0004 4910 6535Laboratory for Epigenetics and Environment, Centre National de Recherche en Génomique Humain, CEA-Institut de Biologie Francois Jacob, Université Paris-Saclay, Evry, France
| | - Miquel Ensenyat-Mendez
- grid.507085.fCancer Epigenetics Laboratory at the Cancer Cell Biology Group, Institut d’Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Diego M. Marzese
- grid.507085.fCancer Epigenetics Laboratory at the Cancer Cell Biology Group, Institut d’Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Anne Pradines
- grid.15781.3a0000 0001 0723 035XInserm, CNRS, Centre de Recherches en Cancérologie de Toulouse, Université de Toulouse, Université Toulouse III-Paul Sabatier, Toulouse, France ,grid.417829.10000 0000 9680 0846Laboratoire de Biologie Médicale Oncologique, Institut Claudius Regaud, Institut Universitaire du Cancer de Toulouse-Oncopole, Toulouse, France
| | - Gilles Favre
- grid.15781.3a0000 0001 0723 035XInserm, CNRS, Centre de Recherches en Cancérologie de Toulouse, Université de Toulouse, Université Toulouse III-Paul Sabatier, Toulouse, France ,grid.417829.10000 0000 9680 0846Laboratoire de Biologie Médicale Oncologique, Institut Claudius Regaud, Institut Universitaire du Cancer de Toulouse-Oncopole, Toulouse, France
| | - Laurence Lamant
- grid.488470.7Laboratoire d’Anatomopathologie, Institut Universitaire du Cancer Toulouse Oncopole, Toulouse, France
| | - Luisa Lanfrancone
- grid.15667.330000 0004 1757 0843Department of Experimental Oncology, Instituto Europeo di Oncologia, Via Adamello 16, 20139 Milan, Italy
| | - Chantal Etievant
- Unité de Service et de Recherche USR n°3388 CNRS-Pierre Fabre, Epigenetic Targeting of Cancer (ETaC), Toulouse, France
| | - Paola B. Arimondo
- Unité de Service et de Recherche USR n°3388 CNRS-Pierre Fabre, Epigenetic Targeting of Cancer (ETaC), Toulouse, France ,grid.428999.70000 0001 2353 6535EpiCBio, Epigenetic Chemical Biology, Department Structural Biology and Chemistry, CNRS UMR N°3523, Institut Pasteur, 28 Rue du Dr Roux, 75015 Paris, France
| | - Joëlle Riond
- Unité de Service et de Recherche USR n°3388 CNRS-Pierre Fabre, Epigenetic Targeting of Cancer (ETaC), Toulouse, France ,grid.15781.3a0000 0001 0723 035XInserm, CNRS, Centre de Recherches en Cancérologie de Toulouse, Université de Toulouse, Université Toulouse III-Paul Sabatier, Toulouse, France
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Carrier A, Desjobert C, Ponger L, Lamant L, Bustos M, Torres-Ferreira J, Henrique R, Jeronimo C, Lanfrancone L, Delmas A, Favre G, Delaunay A, Busato F, Hoon DSB, Tost J, Etievant C, Riond J, Arimondo PB. DNA methylome combined with chromosome cluster-oriented analysis provides an early signature for cutaneous melanoma aggressiveness. eLife 2022; 11:78587. [PMID: 36125262 PMCID: PMC9525058 DOI: 10.7554/elife.78587] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 09/18/2022] [Indexed: 11/24/2022] Open
Abstract
Aberrant DNA methylation is a well-known feature of tumours and has been associated with metastatic melanoma. However, since melanoma cells are highly heterogeneous, it has been challenging to use affected genes to predict tumour aggressiveness, metastatic evolution, and patients’ outcomes. We hypothesized that common aggressive hypermethylation signatures should emerge early in tumorigenesis and should be shared in aggressive cells, independent of the physiological context under which this trait arises. We compared paired melanoma cell lines with the following properties: (i) each pair comprises one aggressive counterpart and its parental cell line and (ii) the aggressive cell lines were each obtained from different host and their environment (human, rat, and mouse), though starting from the same parent cell line. Next, we developed a multi-step genomic pipeline that combines the DNA methylome profile with a chromosome cluster-oriented analysis. A total of 229 differentially hypermethylated genes was commonly found in the aggressive cell lines. Genome localization analysis revealed hypermethylation peaks and clusters, identifying eight hypermethylated gene promoters for validation in tissues from melanoma patients. Five Cytosine-phosphate-Guanine (CpGs) identified in primary melanoma tissues were transformed into a DNA methylation score that can predict survival (log-rank test, p=0.0008). This strategy is potentially universally applicable to other diseases involving DNA methylation alterations.
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Affiliation(s)
- Arnaud Carrier
- Unité de Service et de Recherche USR 3388, CNRS-Pierre Fabre, Toulouse, France
| | - Cécile Desjobert
- Unité de Service et de Recherche USR 3388, CNRS-Pierre Fabre, Toulouse, France
| | | | - Laurence Lamant
- Cancer Research Center of Toulouse, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Matias Bustos
- Department of Translational Molecular Medicine, Providence Saint John's Health Center, Santa Monica, United States
| | - Jorge Torres-Ferreira
- Cancer Biology and Epigenetics Group, Portuguese Oncology Institute, Porto, Portugal
| | - Rui Henrique
- Cancer Biology and Epigenetics Group, Portuguese Oncology Institute, Porto, Portugal
| | - Carmen Jeronimo
- Cancer Biology and Epigenetics Group, Portuguese Oncology Institute, Porto, Portugal
| | - Luisa Lanfrancone
- Department of Experimental Oncology, Instituto Europeo di Oncologia, Milan, Italy
| | - Audrey Delmas
- Cancer Research Center of Toulouse, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Gilles Favre
- Cancer Research Center of Toulouse, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Antoine Delaunay
- Laboratory for Functional Genomics, Fondation Jean Dausset-CEPH, Paris, France
| | - Florence Busato
- Laboratory for Epigenetics and Environment, CNRS, CEA-Institut de Biologie François Jacob, Evry, France
| | - Dave S B Hoon
- Department of Translational Molecular Medicine, Providence Saint John's Health Center, Santa Monica, United States
| | - Jorg Tost
- Laboratory for Epigenetics and Environment, CNRS, CEA-Institut de Biologie François Jacob, Evry, France
| | - Chantal Etievant
- Unité de Service et de Recherche USR 3388, CNRS-Pierre Fabre, Toulouse, France
| | - Joëlle Riond
- Unité de Service et de Recherche USR 3388, CNRS-Pierre Fabre, Toulouse, France
| | - Paola B Arimondo
- Department Structural Biology and Chemistry, Institut Pasteur, CNRS UMR 3523, Paris, France
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Pelletier A, Carrier A, Zhao Y, Canouil M, Derhourhi M, Durand E, Berberian-Ferrato L, Greally J, Hughes F, Froguel P, Bonnefond A, Delahaye F. Epigenetic and Transcriptomic Programming of HSC Quiescence Signaling in Large for Gestational Age Neonates. Int J Mol Sci 2022; 23:7323. [PMID: 35806330 PMCID: PMC9267056 DOI: 10.3390/ijms23137323] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/22/2022] [Accepted: 06/28/2022] [Indexed: 02/04/2023] Open
Abstract
Excessive fetal growth is associated with DNA methylation alterations in human hematopoietic stem and progenitor cells (HSPC), but their functional impact remains elusive. We implemented an integrative analysis combining single-cell epigenomics, single-cell transcriptomics, and in vitro analyses to functionally link DNA methylation changes to putative alterations of HSPC functions. We showed in hematopoietic stem cells (HSC) from large for gestational age neonates that both DNA hypermethylation and chromatin rearrangements target a specific network of transcription factors known to sustain stem cell quiescence. In parallel, we found a decreased expression of key genes regulating HSC differentiation including EGR1, KLF2, SOCS3, and JUNB. Our functional analyses showed that this epigenetic programming was associated with a decreased ability for HSCs to remain quiescent. Taken together, our multimodal approach using single-cell (epi)genomics showed that human fetal overgrowth affects hematopoietic stem cells' quiescence signaling via epigenetic programming.
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Affiliation(s)
- Alexandre Pelletier
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
- Lille University Hospital, University of Lille, 59000 Lille, France
| | - Arnaud Carrier
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
- Lille University Hospital, University of Lille, 59000 Lille, France
| | - Yongmei Zhao
- Department of Obstetrics & Gynecology and Women’s Health, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA;
| | - Mickaël Canouil
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
- Lille University Hospital, University of Lille, 59000 Lille, France
| | - Mehdi Derhourhi
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
| | - Emmanuelle Durand
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
| | - Lionel Berberian-Ferrato
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
| | - John Greally
- Department of Genetics, Albert Einstein College of Medicine, 1301 Morris Park Avenue, Price Building, Room 322, Bronx, NY 10461, USA;
| | - Francine Hughes
- Obstetrics & Gynecology and Women’s Health, Division of Maternal-Fetal Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Philippe Froguel
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
- Lille University Hospital, University of Lille, 59000 Lille, France
- Department of Metabolism, Digestion and Reproduction, Imperial College London, Exhibition Rd, South Kensington, London SW7 2BX, UK
| | - Amélie Bonnefond
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
- Lille University Hospital, University of Lille, 59000 Lille, France
- Department of Metabolism, Digestion and Reproduction, Imperial College London, Exhibition Rd, South Kensington, London SW7 2BX, UK
| | - Fabien Delahaye
- Inserm U1283, CNRS UMR 8199, European Genomic Institute for Diabetes, Institut Pasteur de Lille, 59000 Lille, France; (A.P.); (A.C.); (M.C.); (M.D.); (E.D.); (L.B.-F.); (A.B.)
- Lille University Hospital, University of Lille, 59000 Lille, France
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Lambert E, Saha O, Soares Landeira B, Melo de Farias AR, Hermant X, Carrier A, Pelletier A, Gadaut J, Davoine L, Dupont C, Amouyel P, Bonnefond A, Lafont F, Abdelfettah F, Verstreken P, Chapuis J, Barois N, Delahaye F, Dermaut B, Lambert JC, Costa MR, Dourlen P. The Alzheimer susceptibility gene BIN1 induces isoform-dependent neurotoxicity through early endosome defects. Acta Neuropathol Commun 2022; 10:4. [PMID: 34998435 PMCID: PMC8742943 DOI: 10.1186/s40478-021-01285-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 10/23/2021] [Indexed: 02/08/2023] Open
Abstract
The Bridging Integrator 1 (BIN1) gene is a major susceptibility gene for Alzheimer’s disease (AD). Deciphering its pathophysiological role is challenging due to its numerous isoforms. Here we observed in Drosophila that human BIN1 isoform1 (BIN1iso1) overexpression, contrary to human BIN1 isoform8 (BIN1iso8) and human BIN1 isoform9 (BIN1iso9), induced an accumulation of endosomal vesicles and neurodegeneration. Systematic search for endosome regulators able to prevent BIN1iso1-induced neurodegeneration indicated that a defect at the early endosome level is responsible for the neurodegeneration. In human induced neurons (hiNs) and cerebral organoids, BIN1 knock-out resulted in the narrowing of early endosomes. This phenotype was rescued by BIN1iso1 but not BIN1iso9 expression. Finally, BIN1iso1 overexpression also led to an increase in the size of early endosomes and neurodegeneration in hiNs. Altogether, our data demonstrate that the AD susceptibility gene BIN1, and especially BIN1iso1, contributes to early-endosome size deregulation, which is an early pathophysiological hallmark of AD pathology.
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Desjobert C, Carrier A, Delmas A, Marzese DM, Daunay A, Busato F, Pillon A, Tost J, Riond J, Favre G, Etievant C, Arimondo PB. Demethylation by low-dose 5-aza-2'-deoxycytidine impairs 3D melanoma invasion partially through miR-199a-3p expression revealing the role of this miR in melanoma. Clin Epigenetics 2019; 11:9. [PMID: 30651148 PMCID: PMC6335767 DOI: 10.1186/s13148-018-0600-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 12/17/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Efficient treatments against metastatic melanoma dissemination are still lacking. Here, we report that low-cytotoxic concentrations of 5-aza-2'-deoxycytidine, a DNA demethylating agent, prevent in vitro 3D invasiveness of metastatic melanoma cells and reduce lung metastasis formation in vivo. RESULTS We unravelled that this beneficial effect is in part due to MIR-199A2 re-expression by promoter demethylation. Alone, this miR showed an anti-invasive and anti-metastatic effect. Throughout integration of micro-RNA target prediction databases with transcriptomic analysis after 5-aza-2'-deoxycytidine treatments, we found that miR-199a-3p downregulates set of genes significantly involved in invasion/migration processes. In addition, analysis of data from melanoma patients showed a stage- and tissue type-dependent modulation of MIR-199A2 expression by DNA methylation. CONCLUSIONS Thus, our data suggest that epigenetic- and/or miR-based therapeutic strategies can be relevant to limit metastatic dissemination of melanoma.
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Affiliation(s)
- Cécile Desjobert
- FRE no. 3600 CNRS, Epigenetic Targeting of Cancer (ETaC), Toulouse, France
| | - Arnaud Carrier
- FRE no. 3600 CNRS, Epigenetic Targeting of Cancer (ETaC), Toulouse, France
| | - Audrey Delmas
- Cancer Research Center of Toulouse, CRCT, Toulouse, France
| | - Diego M Marzese
- Department of Translational Molecular Medicine, John Wayne Cancer Institute, Providence Saint John's Health Center, Santa Monica, CA, USA
| | - Antoine Daunay
- Laboratory for Functional Genomics, Fondation Jean Dausset - CEPH, Paris, France
| | - Florence Busato
- Laboratory for Epigenetics and Environment, Centre National de la Recherche en Génomique Humaine, CEA, Evry, France
| | - Arnaud Pillon
- Institut de Recherche Pierre Fabre, CRDPF, Toulouse, France
| | - Jörg Tost
- Laboratory for Epigenetics and Environment, Centre National de la Recherche en Génomique Humaine, CEA, Evry, France
| | - Joëlle Riond
- FRE no. 3600 CNRS, Epigenetic Targeting of Cancer (ETaC), Toulouse, France.,UMR 1037 INSERM/Université Toulouse III, CRCT, Toulouse, France
| | - Gilles Favre
- Cancer Research Center of Toulouse, CRCT, Toulouse, France
| | | | - Paola B Arimondo
- FRE no. 3600 CNRS, Epigenetic Targeting of Cancer (ETaC), Toulouse, France. .,Institut Pasteur CNRS UMR3523, Epigenetic Chemical Biology, Paris, France.
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8
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Bones B, Carrier A, Zinsmeister C, Yen L, Requarth J, Miller P. Infectious sequela after splenic injury: angioembolization is associated with higher infection rates. J Vasc Interv Radiol 2017. [DOI: 10.1016/j.jvir.2016.12.753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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9
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Desjobert C, El Maï M, Gérard-Hirne T, Guianvarc'h D, Carrier A, Pottier C, Arimondo PB, Riond J. Combined analysis of DNA methylation and cell cycle in cancer cells. Epigenetics 2015; 10:82-91. [PMID: 25531272 DOI: 10.1080/15592294.2014.995542] [Citation(s) in RCA: 30] [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] [Indexed: 10/22/2022] Open
Abstract
DNA methylation is a chemical modification of DNA involved in the regulation of gene expression by controlling the access to the DNA sequence. It is the most stable epigenetic mark and is widely studied for its role in major biological processes. Aberrant DNA methylation is observed in various pathologies, such as cancer. Therefore, there is a great interest in analyzing subtle changes in DNA methylation induced by biological processes or upon drug treatments. Here, we developed an improved methodology based on flow cytometry to measure variations of DNA methylation level in melanoma and leukemia cells. The accuracy of DNA methylation quantification was validated with LC-ESI mass spectrometry analysis. The new protocol was used to detect small variations of cytosine methylation occurring in individual cells during their cell cycle and those induced by the demethylating agent 5-aza-2'-deoxycytidine (5AzadC). Kinetic experiments confirmed that inheritance of DNA methylation occurs efficiently in S phase and revealed a short delay between DNA replication and completion of cytosine methylation. In addition, this study suggests that the uncoupling of 5AzadC effects on DNA demethylation and cell proliferation might be related to the duration of the DNA replication phase.
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Affiliation(s)
- Cécile Desjobert
- a CNRS - Pierre Fabre USR 3388 ETaC; CRDPF BP12562 ; Toulouse , France
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10
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Etiévant C, Desjobert C, Carrier A, Delmas A, Tost J, Favre G, Riond J, Arimondo P. Abstract 5524: 5-aza-2′-deoxycytidine, a DNA demethylating agent, inhibits metastatic melanoma invasiveness. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-5524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Metastatic melanomas are the deadliest form of skin cancer and are very aggressive tumors showing highly invasive properties and a rapid chemoresistance to standard treatment (Dacarbazine) and to specific BRAF-V600E kinase inhibitors (Vemurafenib). Thus, targeting these tumors remains a major concern for novel therapeutic proposals.
Abnormal patterns of DNA methylation, an epigenetic modification that cells use to control gene expression, have been described in these tumors. These epigenetic modifications participate in melanoma formation and maintenance. The aim of our project is to characterize the DNA methylation changes that occur in the most aggressive form of melanoma and to reverse these changes by using clinically active DNA methyltransferase inhibitors (5-aza-2′-deoxycytidine, 5-aza-dC). To date a limited number of datasets have been published depicting the effects of inhibitors of DNA methylation on invasive capacities of metastatic melanoma cells. The work presented here, focuses on the study of the effects of DNA methylation inhibition on metastatic melanoma invasiveness.
We have set up an original method to quantify DNA methylation by FACS and shown that non cytotoxic nanomolar 5-aza-dC concentrations were able to demethylate DNA of WM-266-4 metastatic melanoma cells. Then using an in vitro 3D spheroids cell invasion assay and fluorescent microscopy to measure invasion capacities of metastatic cell lines, we showed that 5-aza-dC was able to inhibit invasion of WM-266-4 cells at these non-cytotoxic demethylating concentrations.
Citation Format: Chantal Etiévant, Cécile Desjobert, Arnaud Carrier, Audrey Delmas, Jorg Tost, Gilles Favre, Joelle Riond, Paola Arimondo. 5-aza-2′-deoxycytidine, a DNA demethylating agent, inhibits metastatic melanoma invasiveness. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5524. doi:10.1158/1538-7445.AM2014-5524
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11
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Hamlaoui S, Mokni M, Limam N, Zouaoui K, Ben Rayana MC, Carrier A, Limam F, Amri M, Marzouki L, Aouani E. Protective effect of grape seed and skin extract on garlic-induced erythrocyte oxidative stress. J Physiol Pharmacol 2012; 63:381-388. [PMID: 23070087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Accepted: 07/26/2012] [Indexed: 06/01/2023]
Abstract
High garlic dose could exert adverse health properties and grape seed and skin extract (GSSE) exhibit a variety of beneficial effects, even at high dose. In the present study we evaluated the toxic effect of high garlic dose treatment on antioxidant status of the blood compartment and the protective effect of GSSE. Rats were intraperitoneally (i.p.) administered either with garlic extract (5 g/kg bw) or GSSE (500 mg/kg bw) or a combination of garlic and GSSE at the same doses daily during one month. Plasma parameters and erythrocytes antioxidant status were evaluated. Data confirmed that high garlic dose induced anemia and a pro-oxidative state into erythrocytes characterized by increased malondialdehyde (MDA), carbonyl protein and antioxidant enzyme activities as catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD). Garlic also elevated intracellular hydrogen peroxide (H(2)O(2)) and free iron whereas GSSE treatment counteracted almost all garlic deleterious effects. In conclusion, high garlic dose induced a pro-oxidative state into erythrocytes via the Fenton reaction between H(2)O(2) and free iron, and GSSE exerted antioxidant properties.
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Affiliation(s)
- S Hamlaoui
- Laboratoire de Neurophysiologie Fonctionnelle et Pathologies, Département des Sciences Biologiques, Tunis, Tunisie.
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12
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Hamlaoui S, Mokni M, Limam N, Carrier A, Limam F, Amri M, Marzouki L, Aouani E. Resveratrol protects against acute chemotherapy toxicity induced by doxorubucin in rat erythrocyte and plasma. J Physiol Pharmacol 2012; 63:293-301. [PMID: 22791644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 06/11/2012] [Indexed: 06/01/2023]
Abstract
Doxorubicin (Dox), a widely used antitumor anthracycline antibiotic, plays an undisputed key role in the treatment of many neoplasic diseases. In this study, the protective role of resveratrol against Dox-induced erythrocytes and plasma toxicity has been evaluated in rats. Animals were treated with resveratrol (25 mg/kg b.w.) by intraperitoneal injection during 8 days. At the 4(th) day of treatment, rats were intraperitoneally injected with a single dose of Dox (20 mg/kg b.w.). At the end of the treatment, blood samples were collected following standard procedure and processed for oxidative stress parameters (malondialdehyde (MDA), carbonyl protein, free iron, calcium and H(2)O(2) levels), transaminases and antioxidant enzymes as catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD). Data showed that Dox drastically increased erythrocytes and plasma MDA, free iron, H(2)O(2) and carbonyl proteins but decreased calcium levels and also decreased erythrocytes CAT, POD and SOD activity. Besides, Dox decreased plasma CAT and SOD but unexpectedly increased POD activity. Dox also increased plasma ALT and AST levels and decreased them into erythrocytes. Co-treatment with resveratrol counteracted almost all Dox's effects. In conclusion, Dox induced a pro-oxidative stress into erythrocytes and resveratrol exerted real antioxidant properties which can be attributed, at least in part, to free iron and calcium modulation.
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Affiliation(s)
- S Hamlaoui
- Laboratoire de Neurophysiologie Fonctionnelle et Pathologies, Departement des Sciences Biologiques, Faculte des Sciences, Tunis, Tunisie.
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13
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Seux M, Peuget S, Montero MP, Siret C, Rigot V, Clerc P, Gigoux V, Pellegrino E, Pouyet L, N'Guessan P, Garcia S, Dufresne M, Iovanna JL, Carrier A, André F, Dusetti NJ. TP53INP1 decreases pancreatic cancer cell migration by regulating SPARC expression. Oncogene 2011; 30:3049-61. [PMID: 21339733 DOI: 10.1038/onc.2011.25] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tumor protein 53 induced nuclear protein 1 (TP53INP1) is a p53 target gene that induces cell growth arrest and apoptosis by modulating p53 transcriptional activity. TP53INP1 interacts physically with p53 and is a major player in the p53-driven oxidative stress response. Previously, we demonstrated that TP53INP1 is downregulated in an early stage of pancreatic cancerogenesis and when restored is able to suppress pancreatic tumor development. TP53INP1 downregulation in pancreas is associated with an oncogenic microRNA miR-155. In the present work, we studied the effects of TP53INP1 on cell migration. We found that TP53INP1 inactivation correlates with increased cell migration both in vivo and in vitro. The impact of TP53INP1 expression on cell migration was studied in different cellular contexts: mouse embryonic fibroblast and different pancreatic cancer cell lines. Its expression decreases cell migration by the transcriptional downregulation of secreted protein acidic and rich in cysteine (SPARC). SPARC is a matrix cellular protein, which governs diverse cellular functions and has a pivotal role in regulating cell-matrix interactions, cellular proliferation and migration. SPARC was also showed to be upregulated in normal pancreas and in pancreatic intraepithelial neoplasia lesions in a pancreatic adenocarcinoma mouse model only in the TP53INP1-deficient animals. This novel TP53INP1 activity on the regulation of SPARC expression could explain in part its tumor suppressor function in pancreatic adenocarcinoma by modulating cellular spreading during the metastatic process.
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Affiliation(s)
- M Seux
- INSERM, U624 Stress cellulaire, Marseille, France
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14
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Garcia S, Hervieu V, Lépinasse F, Carrier A, DuSetti N, Iovanna J, Scoazec J, Pébusque M. Signification pronostique de l’expression de TP53INP1 dans les tumeurs endocrines digestives et pancréatiques. Ann Pathol 2006. [DOI: 10.1016/s0242-6498(06)78433-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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15
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Wurbel MA, Malissen M, Guy-Grand D, Meffre E, Nussenzweig MC, Richelme M, Carrier A, Malissen B. Mice lacking the CCR9 CC-chemokine receptor show a mild impairment of early T- and B-cell development and a reduction in T-cell receptor gammadelta(+) gut intraepithelial lymphocytes. Blood 2001; 98:2626-32. [PMID: 11675330 DOI: 10.1182/blood.v98.9.2626] [Citation(s) in RCA: 246] [Impact Index Per Article: 10.7] [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] Open
Abstract
CC chemokine receptor (CCR) 9, the receptor for the CC-chemokine CCL25/thymus-expressed chemokine (TECK), is mainly expressed by thymocytes and by intraepithelial (IEL) and lamina propria lymphocytes of the small intestine. To study the biologic role of CCR9, a mouse strain was generated in which the CCR9 gene was deleted. In spite of the high level of CCR9 found in double- and single-positive thymocytes and of the expression of its corresponding ligand on thymic stromal cells, CCR9 deletion had no major effect on intrathymic T-cell development. It was noted that there was only a one-day lag in the appearance of double-positive cells during fetal ontogeny in CCR9(-/-) thymi. When tested in chemotaxis assay, thymocytes isolated from CCR9(-/-) mice failed to respond to TECK/CCL25. Taken together, these results suggest that in thymocytes, CCR9 is the only physiologic receptor for TECK/CCL25, and that it is dispensable for proper T-cell development. Bone marrow pre-pro-B cells migrate in response to TECK/CCL25, but more mature B cells do not. Consistent with this observation, it was shown that there are fewer pre-pro-B cells in CCR9(-/-) mice than in wild-type mice. However, this diminution does not appear to have a detectable effect on the generation of a normal complement of mature B cells. Finally, it was shown that in the small intestine of CCR9-deficient mice, the intraepithelial T-cell-to-epithelial cell ratio is decreased, an observation that can be accounted for by a marked diminution of the T-cell receptor gammadelta(+) compartment.
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MESH Headings
- Animals
- B-Lymphocytes/cytology
- B-Lymphocytes/drug effects
- Cell Count
- Cell Differentiation
- Cell Division
- Chemokines, CC/pharmacology
- Chemotaxis/drug effects
- Epithelial Cells/drug effects
- Fetus
- Intestine, Small/cytology
- Mice
- Mice, Knockout
- Receptors, Antigen, T-Cell, gamma-delta/drug effects
- Receptors, CCR
- Receptors, Chemokine/deficiency
- Receptors, Chemokine/genetics
- Receptors, Chemokine/physiology
- T-Lymphocytes/cytology
- T-Lymphocytes/drug effects
- Thymus Gland/cytology
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Affiliation(s)
- M A Wurbel
- Centre d'Immunologie de Marseille-Luminy, INSERM-CNRS- Universite de la Mediterranee, Campus de Luminy, Marseille, France
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16
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Carrier A, Parent J. Modification of a commercial electrospray nebulizer for operation in a liquid chromatography/mass spectrometry system at flow rates in the low microL/min range. Rapid Commun Mass Spectrom 2001; 15:1681-1684. [PMID: 11555866 DOI: 10.1002/rcm.410] [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] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A simple and inexpensive approach to convert the electrospray nebulizer of a commercial liquid chromatography/mass spectrometry (LC/MS) system (HP 1100) to accommodate lower flow rates has been proposed and evaluated. This modification consists of simply replacing the nebulizer needle by a commercially available stainless steel needle with a smaller internal diameter. Experiments were conducted in order to optimize operational parameters. Using two different internal diameter needle sizes, flow rates ranging from 1 to 250 microL/min could be accommodated. The modification presented allows an extension of the range of compatible flow rates without major modification of the standard design of the interface.
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Affiliation(s)
- A Carrier
- RTP Pharma Inc., 1000 Chemin du Golf, Ile des Soeurs, Québec, Canada, H3E 1H4.
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17
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Carrier A, Wurbel MA, Mattei MG, Kissenpfennig A, Malissen M, Malissen B. Chromosomal localization of two mouse genes encoding thymus-specific serine peptidase and thymus-expressed acidic protein. Immunogenetics 2000; 51:984-6. [PMID: 11003393 DOI: 10.1007/s002510000230] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A Carrier
- Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, Marseille, France.
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18
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Carrier A, Parent J. Liquid chromatographic-mass spectrometric determination of itraconazole and its major metabolite, hydroxyitraconazole, in dog plasma. J Chromatogr B Biomed Sci Appl 2000; 745:413-20. [PMID: 11043759 DOI: 10.1016/s0378-4347(00)00309-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A fast, reliable and sensitive liquid chromatography-mass spectrometry (LC-MS) assay for the determination of itraconazole and hydroxyitraconazole in dog plasma has been developed. The analysis involves a simple liquid-liquid extraction followed by LC-MS analysis using electrospray ionization in the positive mode. Total separation of itraconazole, hydroxyitraconazole and the internal standard, miconazole, was achieved on a C18 column in 3.5 min using an isocratic mixture of acetonitrile and 10 mM ammonium acetate. The response was linear over four-orders of magnitude, allowing reliable quantification of each species. This paper describes the development of the method and its validation.
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Affiliation(s)
- A Carrier
- RTP Pharma Inc, Verdun, Québec, Canada.
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Carrier A, Parent J, Dupuis S. Quantitation and characterization of phospholipids in pharmaceutical formulations by liquid chromatography-mass spectrometry. J Chromatogr A 2000; 876:97-109. [PMID: 10823505 DOI: 10.1016/s0021-9673(00)00148-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [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: 11/19/2022]
Abstract
A simple and fast method for phospholipid analysis was developed using high-performance liquid chromatography-mass spectrometry with an atmospheric pressure ionization interface. Separation of the phospholipid molecular species was achieved using a linear gradient of a mixture of chloroform-10 mM ammonium acetate-methanol (30:5:65) on a silica column. Optimization of the mass spectrometer conditions has allowed the method to separate and detect the phospholipids mainly as protonated molecular species. In comparison to existing LC-MS methods, improvement in the total analysis time and sensitivity were achieved. Separation of all major phospholipid molecular classes was achieved in less than 6 min. Marked improvement was observed in the linearity of the response of the phospholipids studied providing a linear response over three orders of magnitude. Data supporting the validation of this method for the characterization of major phospholipids molecular species are also presented.
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Affiliation(s)
- A Carrier
- RTP Pharma Inc., Ile des Soeurs, Québec, Canada.
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20
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Wurbel MA, Philippe JM, Nguyen C, Victorero G, Freeman T, Wooding P, Miazek A, Mattei MG, Malissen M, Jordan BR, Malissen B, Carrier A, Naquet P. The chemokine TECK is expressed by thymic and intestinal epithelial cells and attracts double- and single-positive thymocytes expressing the TECK receptor CCR9. Eur J Immunol 2000. [PMID: 10602049 DOI: 10.1002/1521-4141(200001)30:1<262::aid-immu262>3.0.co;2-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Chemokines are key regulators of migration in lymphoid tissues. In the thymus, maturing thymocytes move from the outer capsule to the inner medulla and thereby interact with different types of stromal cells that control their maturation and selection. In the process of searching for molecules specifically expressed at different stages of mouse thymic differentiation, we have characterized the cDNA coding for the thymus-expressed chemokine (TECK) and its receptor CCR9. The TECK receptor gene was isolated and shown to be localized on the mouse chromosome 9F1-F4. Thymic dendritic cells have been initially thought to be a prevalent source of TECK. In contrast, our results indicate that thymic epithelial cells constitute the predominant source of TECK. Consistent with the latter distribution, the TECK receptor is highly expressed by double-positive thymocytes, and TECK can chemoattract both double-positive and single-positive thymocytes. The TECK transcript is also abundantly expressed in the epithelial cells lining the small intestine. In conclusion, the interplay of TECK and its receptor CCR9 is likely to have a significant role in the recruitment of developing thymocytes to discrete compartments of the thymus.
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Affiliation(s)
- M A Wurbel
- Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, Marseille, France
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21
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Wurbel MA, Philippe JM, Nguyen C, Victorero G, Freeman T, Wooding P, Miazek A, Mattei MG, Malissen M, Jordan BR, Malissen B, Carrier A, Naquet P. The chemokine TECK is expressed by thymic and intestinal epithelial cells and attracts double- and single-positive thymocytes expressing the TECK receptor CCR9. Eur J Immunol 2000; 30:262-71. [PMID: 10602049 DOI: 10.1002/1521-4141(200001)30:1<262::aid-immu262>3.0.co;2-0] [Citation(s) in RCA: 258] [Impact Index Per Article: 10.8] [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: 11/07/2022]
Abstract
Chemokines are key regulators of migration in lymphoid tissues. In the thymus, maturing thymocytes move from the outer capsule to the inner medulla and thereby interact with different types of stromal cells that control their maturation and selection. In the process of searching for molecules specifically expressed at different stages of mouse thymic differentiation, we have characterized the cDNA coding for the thymus-expressed chemokine (TECK) and its receptor CCR9. The TECK receptor gene was isolated and shown to be localized on the mouse chromosome 9F1-F4. Thymic dendritic cells have been initially thought to be a prevalent source of TECK. In contrast, our results indicate that thymic epithelial cells constitute the predominant source of TECK. Consistent with the latter distribution, the TECK receptor is highly expressed by double-positive thymocytes, and TECK can chemoattract both double-positive and single-positive thymocytes. The TECK transcript is also abundantly expressed in the epithelial cells lining the small intestine. In conclusion, the interplay of TECK and its receptor CCR9 is likely to have a significant role in the recruitment of developing thymocytes to discrete compartments of the thymus.
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Affiliation(s)
- M A Wurbel
- Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, Marseille, France
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22
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Carrier A, Nguyen C, Victorero G, Granjeaud S, Rocha D, Bernard K, Miazek A, Ferrier P, Malissen M, Naquet P, Malissen B, Jordan BR. Differential gene expression in CD3epsilon- and RAG1-deficient thymuses: definition of a set of genes potentially involved in thymocyte maturation. Immunogenetics 1999; 50:255-70. [PMID: 10630289 DOI: 10.1007/s002510050601] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [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: 10/28/2022]
Abstract
A set of 3000 mouse thymus cDNAs was analyzed by extensive measurement of expression using complex-probe hybridization of DNA arrays ("quantitative differential screening"). The complex probes were initially prepared using total thymus RNA isolated from C57BL/6 wild-type (WT), CD3epsilon- and RAG1-deficient mice. Over 100 clones displaying over- or under-expression by at least a factor of two between WT and knockout (KO) thymuses were further analyzed by measuring hybridization signatures with probes from a wide range of KO thymuses, cell types, organs, and embryonic thymuses. A restricted set of clones was selected by virtue of their expression spectra (modulation in KO thymuses and thymocytes, lymphoid cell specificity, and differential expression during embryonic thymus development), sequenced at one extremity, and compared to sequences in databases. Clones corresponding to previously identified genes (e.g., Tcrbeta, Tcf1 or CD25) showed expression patterns that were consistent with existing data. Ten distinct clones corresponding to new genes were subjected to further study: Northern blot hybridization, in situ hybridization on thymus sections, and partial or complete mRNA sequence determination. Among these genes, we report a new serine peptidase highly expressed in cortical epithelial cells that we have named thymus-specific serine peptidase (TSSP), and an acidic protein expressed in thymocytes and of unknown function that we have named thymus-expressed acidic protein (TEAP). This approach identifies new molecules likely to be involved in thymocyte differentiation and function.
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MESH Headings
- Alternative Splicing
- Amino Acid Sequence
- Animals
- Blotting, Northern
- CD3 Complex/metabolism
- DNA, Complementary/metabolism
- Gene Expression Regulation
- Genes, T-Cell Receptor/genetics
- Homeodomain Proteins/metabolism
- Humans
- In Situ Hybridization
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Models, Genetic
- Molecular Sequence Data
- Nucleic Acid Hybridization
- RNA, Messenger/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Sequence Homology, Amino Acid
- Thymus Gland/growth & development
- Thymus Gland/metabolism
- Tissue Distribution
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Affiliation(s)
- A Carrier
- Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, Case 906, Marseille, France.
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23
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Abstract
After a decade of research, the parent-held Personal Child Health Record was introduced in some parts of the United Kingdom in 1991, coinciding with the enforcement of the Children Act 1989. It was designed as the main record of a child's health and development, to be used until adulthood and to be held by parents. Several Health Care Trusts have since discovered a need to maintain parallel records in the best interests of children. Barnet introduced the 'Joint Professional Record' in 1995 for selected children, such as children on the Child Protection Register. The Joint Professional Record (JPR) is a single, clinic-held, parallel record for multidisciplinary use. We undertook a programme of audit and staff seminars to develop and evaluate use of the JPR. We discuss, below, the impact of this record on professional working relationships and consider the implications of its use as a confidential record and within our policy of working in partnership with parents. In our experience, the JPR has proved a useful adjunct to clinical supervision in the arena of Child Protection and is appropriately used for children in need of protection and those with 'special needs'.
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Affiliation(s)
- R Knowles
- Children's Services, Barnet Healthcare NHS Trust, Colindale Hospital, London, UK
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24
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Queiroz RG, Carrier A, Victorero G, Jordan B, Passos GA. Chromosomal location of the human immunoglobulin lambda variable 8 (IGLV8) gene family outside the major lambda locus on chromosome 22q11.2. Immunol Lett 1997; 59:177-80. [PMID: 9419025 DOI: 10.1016/s0165-2478(97)00122-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 02/05/2023]
Abstract
Physical mapping of the human immunoglobulin lambda locus (IGL) on chromosome 22q11 has shown the existence of at least 52 variable region gene segments. These Vlambda genes are associated with EcoRI fragments detectable in Southern blots of genomic DNA samples. The current physical map of the IGL locus includes a unique Vlambda8 gene (IGL8a, accession no. Z73650) in a 3.7 kb EcoRI fragment. However, our Southern blot-EcoRI-restriction fragment length polymorphism studies on the Brazilian population using a specific probe for the Vlambda8 gene (pVL8 probe) have revealed the presence of two additional fragments bearing Vlambda8 sequences (8.0 kilobase (kb) at 100% frequency and 6.0 kb at 10% frequency). We have used human/rodent somatic cell hybrid DNAs to locate these new Vlambda8 genes outside the major locus on chromosome 22q11.2. Polymerase chain reactions using specific primers for the IGLV8a gene on the somatic hybrid panel showed that chromosome 8 (besides 22q11) also comprises Vlambda8 sequences. This finding represents evidence for the dispersion of the human IGLV8 gene family outside the major locus (orphan genes).
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Affiliation(s)
- R G Queiroz
- Dept. Genética, Faculdade de Medicina de Ribeirão Preto, USP, Brazil
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25
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Rocha D, Carrier A, Naspetti M, Victorero G, Anderson E, Botcherby M, Guénet JL, Nguyen C, Naquet P, Jordan BR. Modulation of mRNA levels in the presence of thymocytes and genome mapping for a set of genes expressed in mouse thymic epithelial cells. Immunogenetics 1997; 46:142-51. [PMID: 9162101 DOI: 10.1007/s002510050253] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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: 02/04/2023]
Abstract
Modulation of gene expression in mouse thymic epithelium upon culture in the presence of thymocytes (coculture) was studied by comparison of hybridization signatures on a set of nearly 5000 mouse thymus cDNA clones. Forty-nine differentially expressed clones (usually down-regulated in coculture) were characterized by tag sequencing. Many of them corresponded to entities that had not been described previously in the mouse, and were further characterized by genome mapping. This set of genes appears to be involved in growth regulation and differentiation within the thymus.
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Affiliation(s)
- D Rocha
- Genome Structure and Immune Functions Laboratory, Centre d'Immunologie INSERM-CNRS de Marseille-Luminy (CIML), Case 906, 13288 Marseille, Cedex 9, France
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26
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Carrier A, Rosier MF, Guillemot F, Goguel AF, Pulcini F, Bernheim A, Auffray C, Devignes MD. Integrated physical, genetic, and genic map covering 3 Mb around the human NGF gene (NGFB) at 1p13. Genomics 1996; 31:80-9. [PMID: 8808283 DOI: 10.1006/geno.1996.0012] [Citation(s) in RCA: 4] [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: 02/02/2023]
Abstract
We have characterized 11 overlapping yeast artificial chromosomes (YACs) in the 1p13 region, 8 of them containing the human nerve growth factor (NGF) gene (HGMW-approved symbol NGFB). Sequence-tagged sites (STSs) corresponding to YAC extremities have been designed and used for chromosome assignment on a panel of monochromosomic somatic cell hybrids to check for YAC chimerism, in parallel with analyses by fluorescence in situ hybridization. Determination of end STS content and restriction mapping of the YACs led to the construction of a 3-Mb YAC contig. Four microsatellite markers from the Généthon collection and seven genes known to map to the 1p13 region have been ordered on the contig around the NGF gene. A new gene transcript from the Genexpress catalog has been localized on the contig. This work provides an integrated physical, genetic, and genic map of this chromosome 1 region. It constitutes a basis for determining the structure of the NGF gene and for further characterizing its genic environment.
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Affiliation(s)
- A Carrier
- Génétique Moléculaire et Biologie du Développement, CNRS-UPR 420, Villejuif, France
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27
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Carrier A, Ducancel F, Settiawan NB, Cattolico L, Maillère B, Léonetti M, Drevet P, Ménez A, Boulain JC. Recombinant antibody-alkaline phosphatase conjugates for diagnosis of human IgGs: application to anti-HBsAg detection. J Immunol Methods 1995; 181:177-86. [PMID: 7745247 DOI: 10.1016/0022-1759(94)00344-v] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [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: 01/26/2023]
Abstract
We have designed an expression vector permitting the production in the periplasm of Escherichia coli of a fusion protein comprising a dimer of bacterial alkaline phosphatase (PhoA) and two Fab or scFv fragments of a monoclonal antibody directed against human IgG. Each hybrid protein expressed both high specificity for the antigen and full PhoA activity. We show that crude periplasmic extracts containing these conjugates can be used as such in enzyme immunoassays for the detection of human IgG, as exemplified in the case of anti-hepatitis B immunoglobulin.
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Affiliation(s)
- A Carrier
- Département d'Ingénierie et d'Etudes des Protéines, C.E.A. Saclay, Gif/Yvette, France
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28
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Abstract
Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the biosynthesis of catecholamines. We describe here the isolation of the chicken TH gene and the analysis of 3 kb of its 5' flanking region. The chicken TH transcription unit spans 19 kb. The 60-bp proximal promoter contains a TATA box and a cyclic AMP response element (CRE) sequence. The 5' flanking region contains several AP1-, AP2-, and octamer-like sequences as well as a glucocorticoid response element at position -1.4 kb. A construct containing the 3-kb 5' flanking DNA fused to the chloramphenicol acetyltransferase (CAT) gene was transiently transfected into PC12 cells, and the effect of various effectors was tested. Only forskolin increased the CAT activity, likely owing to the presence of the CRE sequence. Constructs prepared by progressively deleting the 5' flanking DNA were transfected into PC12 and QT6 (quail transformed fibroblasts) cells. In both cell types, the transcriptional activity increased with deletion of the 5' flanking region. These results show that the 60-bp region containing the TATA box and the CRE is sufficient to act as a constitutive promoter for the chicken TH gene and that this region appears to be negatively controlled by upstream sequences.
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Affiliation(s)
- A Carrier
- Unité de Génétique Moléculaire et de Biologie du Développement, CNRS UPR420, Villejuif, France
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29
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Gagné J, Carrier A, Varfalvy L, Bertrand M. Origin of the decrease in chromatographic resolution induced by the addition of viscous matrices in liquid chromatographic—fast atom bombardment mass spectrometric systems. J Chromatogr A 1993. [DOI: 10.1016/0021-9673(93)83320-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Ducancel F, Gillet D, Carrier A, Lajeunesse E, Ménez A, Boulain JC. Recombinant colorimetric antibodies: construction and characterization of a bifunctional F(ab)2/alkaline phosphatase conjugate produced in Escherichia coli. Biotechnology (N Y) 1993; 11:601-5. [PMID: 7763607 DOI: 10.1038/nbt0593-601] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have designed a vector which allows the synthesis in Escherichia coli of bifunctional F(ab)2-alkaline phosphatase conjugates. The vector contains a di-cistronic operon encoding truncated heavy chain (Fd or VH-CH1) of an IgG inserted between residues +6 and +7 of bacterial alkaline phosphatase (PhoA), and the light chain of the same IgG. We demonstrate the utility of this approach with the heavy and light chain domains of a snake toxin-specific monoclonal antibody, M alpha 2-3. We show that the VH-CH1-PhoA hybrid and VL-CL are concomitantly expressed and exported to the periplasm of E. coli where they form a disulfide-linked chimeric protein. The hybrid has the same affinity as M alpha 2-3 for the snake toxin antigen and possesses PhoA enzymatic activity.
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Affiliation(s)
- F Ducancel
- Département d'Ingénierie et d'Etudes des Protéines, C.E.A. Saclay, Gif/Yvette, France
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31
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Abstract
The gene for tyrosine hydroxylase, the first and rate-limiting enzyme in the biosynthetic pathway of catecholamine neurotransmitters, has been localized in situ to chromosome 6 in the chicken. It is the first DNA marker to be reported for this telocentric macrochromosome. Use of a 45-kb biotinylated chicken-specific cosmid probe and a sensitive fluorescent detection system proved to be highly efficient, with over 90% of metaphases showing positive hybridization signals on one or (usually) both chromosome 6 homologs, in physically mapping this single-gene locus.
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32
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Abstract
An NGF cDNA containing the 5' exons of the nerve growth factor (NGF) messenger was obtained from chicken heart mRNA using the anchored polymerase chain reaction technique. Alignment of the chicken with the corresponding murine and human sequences reveals interspecies similarities. A sequence corresponding to an exon found only in the NGF messenger, which is abundant in the submaxillary gland of the male mouse, is present in the chicken NGF cDNA. The first non-coding exons of the NGF gene are much less conserved between chicken and mouse or human than the region of the last exon encoding the mature protein. After the cloning of the chicken NGF gene from a cosmid library, the chicken NGF exons have been located within 20 kb of DNA. The chicken NGF gene is therefore shorter than its murine counterpart which spans more than 43 kb. Furthermore, the organization of the chicken and murine NGF genes markedly differs in their 5' portion.
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Affiliation(s)
- A Carrier
- Unité de Génétique Moléculaire et de Biologie du Développement, CNRS, Villejuif, France
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Mahalik TJ, Carrier A, Owens GP, Clayton G. The expression of GAP43 mRNA during the late embryonic and early postnatal development of the CNS of the rat: an in situ hybridization study. Brain Res Dev Brain Res 1992; 67:75-83. [PMID: 1386294 DOI: 10.1016/0165-3806(92)90027-t] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
GAP43 is a developmentally regulated phosphoprotein which is almost exclusively found in neurons. Numerous correlative studies have shown that GAP43 is expressed at high levels during neurite extension, axonal elongation and synaptogenesis. In this study we used in situ hybridization to examine GAP43 expression during late embryonic and early postnatal development. The highest relative levels of GAP43 at all stages were present in the neocortex. Levels in this and other regions peaked between postnatal days 5 and 10. These results indicate that high levels of GAP43 mRNA correlate most highly with the latter stages of axon outgrowth and with the early stages of synapse formation.
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Affiliation(s)
- T J Mahalik
- Department of Cellular and Structural Biology, University of Colorado, Denver 80262
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34
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Abstract
The chicken nerve growth factor (beta NGF) gene has been mapped by fluorescent in situ hybridization to a pair of microchromosomes, confirming previous reports of the existence of a single gene locus. A 39-kb genomic fragment cloned in a cosmid vector and including the 5' end of the beta NGF locus was biotinylated for nonradioactive detection of the gene. This report adds to the increasing evidence proving microchromosomal localization of highly conserved and biologically fundamental genes. The implications of such genes belonging to very small linkage groups for the transmission of alleles from generation to generation together with the relevance of nonisotopic in situ hybridization for avian gene mapping are considered.
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Affiliation(s)
- M Dominguez-Steglich
- Department of Human Genetics, University of Würzburg, Federal Republic of Germany
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35
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Abstract
A spin-label (P-OPC) composed of the nitroxide-containing ring proxyl linked at the C1 position of the intercalating fluorescent chromophore oxazolopyridocarbazole (OPC) has been synthesized. The spin-labeled OPC was found to interact with DNA and polynucleotides according to an external minor groove binding mode with association constant values Kapp ranging from 10(5) to 10(6) M-1. External binding was obvious from the inability of P-OPC to increase the length of sonicated DNA upon binding, the low unwinding angle (9.6 degrees) of circular PM2 DNA, and the low energy transfer from DNA bases to bound chromophore. Binding of P-OPC to DNA or polynucleotide results in a strong immobilization of the proxyl moiety, resulting in the appearance of an asymmetric and broad ESR spectrum with a maximal hyperfine splitting of 56.5 G. In the equilibrium conditions, the occurrence of superimposed ESR spectra related to the P-OPC fraction undergoing rapid motion and to the P-OPC fraction immobilized allows the estimation of the concentrations of free and DNA-bound spin-label. The external mode of binding to DNA as well as the characteristics of the ESR spectra make P-OPC suitable for the determination of DNA binding parameters of nonintercalating ligands using competition experiments. The measurement of the binding constants of distamycin A to poly[d(A-T)] and poly[d(G-C)] is taken as an example.
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Affiliation(s)
- A Carrier
- INSERM U140, CNRS LA 147, Institut Gustave Roussy, Villejuif, France
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36
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Carrier A. Sequential steps in project execution. International Journal of Project Management 1987. [DOI: 10.1016/0263-7863(87)90006-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Stelling JG, Carrier A, Waller M. The family express: trouble on the line? Can Fam Physician 1981; 27:821-825. [PMID: 21289734 PMCID: PMC2305996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In a recent study, residents completing training in family medicine manifested a surprising degree of diversity in their interpretations of the place of 'family' in practice, had a unique way of relating to their professional role, and expressed a high degree of uncertainty about future careers. Utilizing results from earlier research on professional socialization, explanations for these findings are sought in the structure of the program and characteristics of the staff.
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