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Ng BW, Kaukonen MK, McClements ME, Shamsnajafabadi H, MacLaren RE, Cehajic-Kapetanovic J. Genetic therapies and potential therapeutic applications of CRISPR activators in the eye. Prog Retin Eye Res 2024; 102:101289. [PMID: 39127142 DOI: 10.1016/j.preteyeres.2024.101289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 08/12/2024]
Abstract
Conventional gene therapy involving supplementation only treats loss-of-function diseases and is limited by viral packaging sizes, precluding therapy of large genes. The discovery of CRISPR/Cas has led to a paradigm shift in the field of genetic therapy, with the promise of precise gene editing, thus broadening the range of diseases that can be treated. The initial uses of CRISPR/Cas have focused mainly on gene editing or silencing of abnormal variants via utilising Cas endonuclease to trigger the target cell endogenous non-homologous end joining. Subsequently, the technology has evolved to modify the Cas enzyme and even its guide RNA, leading to more efficient editing tools in the form of base and prime editing. Further advancements of this CRISPR/Cas technology itself have expanded its functional repertoire from targeted editing to programmable transactivation, shifting the therapeutic focus to precise endogenous gene activation or upregulation with the potential for epigenetic modifications. In vivo experiments using this platform have demonstrated the potential of CRISPR-activators (CRISPRa) to treat various loss-of-function diseases, as well as in regenerative medicine, highlighting their versatility to overcome limitations associated with conventional strategies. This review summarises the molecular mechanisms of CRISPRa platforms, the current applications of this technology in vivo, and discusses potential solutions to translational hurdles for this therapy, with a focus on ophthalmic diseases.
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Affiliation(s)
- Benjamin Wj Ng
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Maria K Kaukonen
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK; Department of Medical and Clinical Genetics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Michelle E McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Hoda Shamsnajafabadi
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK.
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Chen H, Wang YD, Blan AW, Almanza-Fuerte EP, Bonkowski ES, Bajpai R, Pruett-Miller SM, Mefford HC. Patient derived model of UBA5-associated encephalopathy identifies defects in neurodevelopment and highlights potential therapies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.25.577254. [PMID: 38328212 PMCID: PMC10849720 DOI: 10.1101/2024.01.25.577254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
UBA5 encodes for the E1 enzyme of the UFMylation cascade, which plays an essential role in ER homeostasis. The clinical phenotypes of UBA5-associated encephalopathy include developmental delays, epilepsy and intellectual disability. To date, there is no humanized neuronal model to study the cellular and molecular consequences of UBA5 pathogenic variants. We developed and characterized patient-derived cortical organoid cultures and identified defects in GABAergic interneuron development. We demonstrated aberrant neuronal firing and microcephaly phenotypes in patient-derived organoids. Mechanistically, we show that ER homeostasis is perturbed along with exacerbated unfolded protein response pathway in cells and organoids expressing UBA5 pathogenic variants. We also assessed two gene expression modalities that augmented UBA5 expression to rescue aberrant molecular and cellular phenotypes. Our study provides a novel humanized model that allows further investigations of UBA5 variants in the brain and highlights novel systemic approaches to alleviate cellular aberrations for this rare, developmental disorder.
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Affiliation(s)
- Helen Chen
- Center for Pediatric Neurological Disease Research, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Yong-Dong Wang
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis TN, USA
| | - Aidan W. Blan
- Center for Pediatric Neurological Disease Research, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Edith P. Almanza-Fuerte
- Center for Pediatric Neurological Disease Research, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Emily S. Bonkowski
- Center for Pediatric Neurological Disease Research, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Richa Bajpai
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis TN, USA
- Center for Advanced Genome Engineering, St. Jude Children’s Research Hospital, Memphis TN, USA
| | - Shondra M. Pruett-Miller
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis TN, USA
- Center for Advanced Genome Engineering, St. Jude Children’s Research Hospital, Memphis TN, USA
| | - Heather C. Mefford
- Center for Pediatric Neurological Disease Research, St. Jude Children’s Research Hospital, Memphis, TN, USA
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Chang YT, Lee YJ, Haque M, Chang HC, Javed S, Lin YC, Cho Y, Abramovitz J, Chin G, Khamis A, Raja R, Murai KK, Huang WH. Comparative analyses of the Smith-Magenis syndrome protein RAI1 in mice and common marmoset monkeys. J Comp Neurol 2024; 532:e25589. [PMID: 38289192 DOI: 10.1002/cne.25589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 11/11/2023] [Accepted: 12/17/2023] [Indexed: 02/01/2024]
Abstract
Retinoic acid-induced 1 (RAI1) encodes a transcriptional regulator critical for brain development and function. RAI1 haploinsufficiency in humans causes a syndromic autism spectrum disorder known as Smith-Magenis syndrome (SMS). The neuroanatomical distribution of RAI1 has not been quantitatively analyzed during the development of the prefrontal cortex, a brain region critical for cognitive function and social behaviors and commonly implicated in autism spectrum disorders, including SMS. Here, we performed comparative analyses to uncover the evolutionarily convergent and divergent expression profiles of RAI1 in major cell types during prefrontal cortex maturation in common marmoset monkeys (Callithrix jacchus) and mice (Mus musculus). We found that while RAI1 in both species is enriched in neurons, the percentage of excitatory neurons that express RAI1 is higher in newborn mice than in newborn marmosets. By contrast, RAI1 shows similar neural distribution in adult marmosets and adult mice. In marmosets, RAI1 is expressed in several primate-specific cell types, including intralaminar astrocytes and MEIS2-expressing prefrontal GABAergic neurons. At the molecular level, we discovered that RAI1 forms a protein complex with transcription factor 20 (TCF20), PHD finger protein 14 (PHF14), and high mobility group 20A (HMG20A) in the marmoset brain. In vitro assays in human cells revealed that TCF20 regulates RAI1 protein abundance. This work demonstrates that RAI1 expression and protein interactions are largely conserved but with some unique expression in primate-specific cells. The results also suggest that altered RAI1 abundance could contribute to disease features in disorders caused by TCF20 dosage imbalance.
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Affiliation(s)
- Ya-Ting Chang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Yu-Ju Lee
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Minza Haque
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Hao-Cheng Chang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Sehrish Javed
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Yu Cheng Lin
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Yoobin Cho
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Joseph Abramovitz
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Gabriella Chin
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Asma Khamis
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Reesha Raja
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Keith K Murai
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Wei-Hsiang Huang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Montréal, Québec, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
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Javed S, Chang YT, Cho Y, Lee YJ, Chang HC, Haque M, Lin YC, Huang WH. Smith-Magenis syndrome protein RAI1 regulates body weight homeostasis through hypothalamic BDNF-producing neurons and neurotrophin downstream signalling. eLife 2023; 12:RP90333. [PMID: 37956053 PMCID: PMC10642964 DOI: 10.7554/elife.90333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023] Open
Abstract
Retinoic acid-induced 1 (RAI1) haploinsufficiency causes Smith-Magenis syndrome (SMS), a genetic disorder with symptoms including hyperphagia, hyperlipidemia, severe obesity, and autism phenotypes. RAI1 is a transcriptional regulator with a pan-neural expression pattern and hundreds of downstream targets. The mechanisms linking neural Rai1 to body weight regulation remain unclear. Here we find that hypothalamic brain-derived neurotrophic factor (BDNF) and its downstream signalling are disrupted in SMS (Rai1+/-) mice. Selective Rai1 loss from all BDNF-producing cells or from BDNF-producing neurons in the paraventricular nucleus of the hypothalamus (PVH) induced obesity in mice. Electrophysiological recordings revealed that Rai1 ablation decreased the intrinsic excitability of PVHBDNF neurons. Chronic treatment of SMS mice with LM22A-4 engages neurotrophin downstream signalling and delayed obesity onset. This treatment also partially rescued disrupted lipid profiles, insulin intolerance, and stereotypical repetitive behaviour in SMS mice. These data argue that RAI1 regulates body weight and metabolic function through hypothalamic BDNF-producing neurons and that targeting neurotrophin downstream signalling might improve associated SMS phenotypes.
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Affiliation(s)
- Sehrish Javed
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Ya-Ting Chang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Yoobin Cho
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Yu-Ju Lee
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Hao-Cheng Chang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Minza Haque
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Yu Cheng Lin
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Wei-Hsiang Huang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
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Guo Q, Wu S, Geschwind DH. Characterization of Gene Regulatory Elements in Human Fetal Cortical Development: Enhancing Our Understanding of Neurodevelopmental Disorders and Evolution. Dev Neurosci 2023; 46:69-83. [PMID: 37231806 DOI: 10.1159/000530929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/24/2023] [Indexed: 05/27/2023] Open
Abstract
The neocortex is the region that most distinguishes human brain from other mammals and primates [Annu Rev Genet. 2021 Nov;55(1):555-81]. Studying the development of human cortex is important in understanding the evolutionary changes occurring in humans relative to other primates, as well as in elucidating mechanisms underlying neurodevelopmental disorders. Cortical development is a highly regulated process, spatially and temporally coordinated by expression of essential transcriptional factors in response to signaling pathways [Neuron. 2019 Sep;103(6):980-1004]. Enhancers are the most well-understood cis-acting, non-protein-coding regulatory elements that regulate gene expression [Nat Rev Genet. 2014 Apr;15(4):272-86]. Importantly, given the conservation of both DNA sequence and molecular function of the majority of proteins across mammals [Genome Res. 2003 Dec;13(12):2507-18], enhancers [Science. 2015 Mar;347(6226):1155-9], which are far more divergent at the sequence level, likely account for the phenotypes that distinguish the human brain by changing the regulation of gene expression. In this review, we will revisit the conceptual framework of gene regulation during human brain development, as well as the evolution of technologies to study transcriptional regulation, with recent advances in genome biology that open a window allowing us to systematically characterize cis-regulatory elements in developing human brain [Hum Mol Genet. 2022 Oct;31(R1):R84-96]. We provide an update on work to characterize the suite of all enhancers in the developing human brain and the implications for understanding neuropsychiatric disorders. Finally, we discuss emerging therapeutic ideas that utilize our emerging knowledge of enhancer function.
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Affiliation(s)
- Qiuyu Guo
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, California, USA
- Center for Autism Research and Treatment, Semel Institute, University of California Los Angeles, Los Angeles, California, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Sarah Wu
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, California, USA
| | - Daniel H Geschwind
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, California, USA
- Center for Autism Research and Treatment, Semel Institute, University of California Los Angeles, Los Angeles, California, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Institute of Precision Health, University of California Los Angeles, Los Angeles, California, USA
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