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An efficient and multiple target transgenic RNAi technique with low toxicity in Drosophila. Nat Commun 2018; 9:4160. [PMID: 30297884 PMCID: PMC6175926 DOI: 10.1038/s41467-018-06537-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 09/12/2018] [Indexed: 01/19/2023] Open
Abstract
Being relatively simple and practical, Drosophila transgenic RNAi is the technique of top priority choice to quickly study genes with pleiotropic functions. However, drawbacks have emerged over time, such as high level of false positive and negative results. To overcome these shortcomings and increase efficiency, specificity and versatility, we develop a next generation transgenic RNAi system. With this system, the leaky expression of the basal promoter is significantly reduced, as well as the heterozygous ratio of transgenic RNAi flies. In addition, it has been first achieved to precisely and efficiently modulate highly expressed genes. Furthermore, we increase versatility which can simultaneously knock down multiple genes in one step. A case illustration is provided of how this system can be used to study the synthetic developmental effect of histone acetyltransferases. Finally, we have generated a collection of transgenic RNAi lines for those genes that are highly homologous to human disease genes.
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Pedard M, Quirié A, Garnier P, Tessier A, Demougeot C, Marie C. The Cerebral Brain-Derived Neurotrophic Factor Pathway, Either Neuronal or Endothelial, Is Impaired in Rats with Adjuvant-Induced Arthritis. Connection with Endothelial Dysfunction. Front Physiol 2018; 8:1125. [PMID: 29375397 PMCID: PMC5767301 DOI: 10.3389/fphys.2017.01125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/20/2017] [Indexed: 01/16/2023] Open
Abstract
Cognitive abilities are largely dependent on activation of cerebral tropomyosin-related kinase B receptors (TrkB) by brain-derived neurotrophic factor (BDNF) that is secreted under a bioactive form by both neurons and endothelial cells. In addition, there is mounting evidence for a link between endothelial function and cognition even though the underlying mechanisms are not well known. Therefore, we investigated the cerebral BDNF pathway, either neuronal or endothelial, in rheumatoid arthritis (RA) that combines both endothelial dysfunction (ED) and impaired cognition. Adjuvant-induced arthritis (AIA) in rats was used as a model of RA. Clinical inflammatory symptoms were evaluated from an arthritis score and brains were collected at day 31 ± 2 post-immunization. Neuronal expression of BDNF and TrkB phosphorylated at tyrosine 816 (p-TrkB) was examined in brain slices. Endothelial BDNF and p-TrkB expression was examined on both brain slices (hippocampal arterioles) and isolated cerebral microvessels-enriched fractions (vessels downstream to arterioles). The connection between endothelial nitric oxide (NO) and BDNF production was explored on the cerebrovascular fractions using endothelial NO synthase (eNOS) levels as a marker of NO production, Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) as a NOS inhibitor and glyceryl-trinitrate as a slow releasing NO donor. Brain slices displayed lower BDNF and p-TrkB staining in both neurons and arteriolar endothelial cells in AIA than in control rats. For endothelial cells but not neurons, a strong correlation was observed between BDNF and p-TrkB staining. Of note, a strong correlation was also observed between neuronal p-TrkB and endothelial BDNF staining. In cerebral microvessels-enriched fractions, AIA led to decreased BDNF and eNOS levels with a positive association between the 2 parameters. These effects coincided with decreased BDNF and p-TrkB staining in endothelial cells. The exposure of AIA cerebrovascular fractions to GTN increased BDNF levels while the exposure of control fractions to L-NAME decreased BDNF levels. Changes in the cerebral BDNF pathway were not associated with arthritis score. The present study reveals that AIA impairs the endothelial and neuronal BDNF/TrkB pathway, irrespective of the severity of inflammatory symptoms but dependent on endothelial NO production. These results open new perspectives for the understanding of the link between ED and impaired cognition.
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Affiliation(s)
- Martin Pedard
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences de Santé, Dijon, France.,Service de Neurologie, CHRU Dijon, Dijon, France
| | - Aurore Quirié
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences de Santé, Dijon, France
| | - Philippe Garnier
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences de Santé, Dijon, France
| | - Anne Tessier
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences de Santé, Dijon, France
| | - Céline Demougeot
- EA4267 PEPITE, FHU INCREASE, University of Bourgogne Franche-Comté, Besançon, France
| | - Christine Marie
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences de Santé, Dijon, France
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Berson A, Sartoris A, Nativio R, Van Deerlin V, Toledo JB, Porta S, Liu S, Chung CY, Garcia BA, Lee VMY, Trojanowski JQ, Johnson FB, Berger SL, Bonini NM. TDP-43 Promotes Neurodegeneration by Impairing Chromatin Remodeling. Curr Biol 2017; 27:3579-3590.e6. [PMID: 29153328 PMCID: PMC5720388 DOI: 10.1016/j.cub.2017.10.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/20/2017] [Accepted: 10/09/2017] [Indexed: 12/12/2022]
Abstract
Regulation of chromatin structure is critical for brain development and function. However, the involvement of chromatin dynamics in neurodegeneration is less well understood. Here we find, launching from Drosophila models of amyotrophic lateral sclerosis and frontotemporal dementia, that TDP-43 impairs the induction of multiple key stress genes required to protect from disease by reducing the recruitment of the chromatin remodeler Chd1 to chromatin. Chd1 depletion robustly enhances TDP-43-mediated neurodegeneration and promotes the formation of stress granules. Conversely, upregulation of Chd1 restores nucleosomal dynamics, promotes normal induction of protective stress genes, and rescues stress sensitivity of TDP-43-expressing animals. TDP-43-mediated impairments are conserved in mammalian cells, and, importantly, the human ortholog CHD2 physically interacts with TDP-43 and is strikingly reduced in level in temporal cortex of human patient tissue. These findings indicate that TDP-43-mediated neurodegeneration causes impaired chromatin dynamics that prevents appropriate expression of protective genes through compromised function of the chromatin remodeler Chd1/CHD2. Enhancing chromatin dynamics may be a treatment approach to amyotrophic lateral scleorosis (ALS)/frontotemporal dementia (FTD).
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Affiliation(s)
- Amit Berson
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ashley Sartoris
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Raffaella Nativio
- Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vivianna Van Deerlin
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jon B Toledo
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sílvia Porta
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shichong Liu
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Chia-Yu Chung
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Benjamin A Garcia
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Virginia M-Y Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - F Brad Johnson
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shelley L Berger
- Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nancy M Bonini
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Mohanty B, Helder S, Silva APG, Mackay JP, Ryan DP. The Chromatin Remodelling Protein CHD1 Contains a Previously Unrecognised C-Terminal Helical Domain. J Mol Biol 2016; 428:4298-4314. [PMID: 27591891 DOI: 10.1016/j.jmb.2016.08.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/25/2016] [Accepted: 08/26/2016] [Indexed: 10/21/2022]
Abstract
The packaging of eukaryotic DNA into nucleosomes, and the organisation of these nucleosomes into chromatin, plays a critical role in regulating all DNA-associated processes. Chromodomain helicase DNA-binding protein 1 (CHD1) is an ATP-dependent chromatin remodelling protein that is conserved throughout eukaryotes and has an ability to assemble and organise nucleosomes both in vitro and in vivo. This activity is involved in the regulation of transcription and is implicated in mammalian development and stem cell biology. CHD1 is classically depicted as possessing a pair of tandem chromodomains that directly precede a core catalytic helicase-like domain that is then followed by a SANT-SLIDE DNA-binding domain. Here, we have identified an additional conserved domain C-terminal to the SANT-SLIDE domain and determined its structure by multidimensional heteronuclear NMR spectroscopy. We have termed this domain the CHD1 helical C-terminal (CHCT) domain as it is comprised of five α-helices arranged in a variant helical bundle topology. CHCT has a conserved, positively charged surface and is able to bind DNA and nucleosomes. In addition, we have identified another group of proteins, the as yet uncharacterised C17orf64 proteins, as also containing a conserved CHCT domain. Our data provide new structural insights into the CHD1 enzyme family.
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Affiliation(s)
- Biswaranjan Mohanty
- School of Life and Environmental Sciences, The University of Sydney, Building G08, Corner Butlin Avenue and Maze Crescent, Sydney, New South Wales, 2006, Australia; Faculty of Pharmacy and Pharmaceutical Sciences, Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia
| | - Stephanie Helder
- School of Life and Environmental Sciences, The University of Sydney, Building G08, Corner Butlin Avenue and Maze Crescent, Sydney, New South Wales, 2006, Australia
| | - Ana P G Silva
- School of Life and Environmental Sciences, The University of Sydney, Building G08, Corner Butlin Avenue and Maze Crescent, Sydney, New South Wales, 2006, Australia
| | - Joel P Mackay
- School of Life and Environmental Sciences, The University of Sydney, Building G08, Corner Butlin Avenue and Maze Crescent, Sydney, New South Wales, 2006, Australia.
| | - Daniel P Ryan
- Department of Genome Sciences, The John Curtin School of Medical Research, Building 131, Garran Road, The Australian National University, Canberra, Australian Capital Territory, 2601, Australia.
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