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Papadimitriou E, Thomaidou D. Post-transcriptional mechanisms controlling neurogenesis and direct neuronal reprogramming. Neural Regen Res 2024; 19:1929-1939. [PMID: 38227517 DOI: 10.4103/1673-5374.390976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/08/2023] [Indexed: 01/17/2024] Open
Abstract
Neurogenesis is a tightly regulated process in time and space both in the developing embryo and in adult neurogenic niches. A drastic change in the transcriptome and proteome of radial glial cells or neural stem cells towards the neuronal state is achieved due to sophisticated mechanisms of epigenetic, transcriptional, and post-transcriptional regulation. Understanding these neurogenic mechanisms is of major importance, not only for shedding light on very complex and crucial developmental processes, but also for the identification of putative reprogramming factors, that harbor hierarchically central regulatory roles in the course of neurogenesis and bare thus the capacity to drive direct reprogramming towards the neuronal fate. The major transcriptional programs that orchestrate the neurogenic process have been the focus of research for many years and key neurogenic transcription factors, as well as repressor complexes, have been identified and employed in direct reprogramming protocols to convert non-neuronal cells, into functional neurons. The post-transcriptional regulation of gene expression during nervous system development has emerged as another important and intricate regulatory layer, strongly contributing to the complexity of the mechanisms controlling neurogenesis and neuronal function. In particular, recent advances are highlighting the importance of specific RNA binding proteins that control major steps of mRNA life cycle during neurogenesis, such as alternative splicing, polyadenylation, stability, and translation. Apart from the RNA binding proteins, microRNAs, a class of small non-coding RNAs that block the translation of their target mRNAs, have also been shown to play crucial roles in all the stages of the neurogenic process, from neural stem/progenitor cell proliferation, neuronal differentiation and migration, to functional maturation. Here, we provide an overview of the most prominent post-transcriptional mechanisms mediated by RNA binding proteins and microRNAs during the neurogenic process, giving particular emphasis on the interplay of specific RNA binding proteins with neurogenic microRNAs. Taking under consideration that the molecular mechanisms of neurogenesis exert high similarity to the ones driving direct neuronal reprogramming, we also discuss the current advances in in vitro and in vivo direct neuronal reprogramming approaches that have employed microRNAs or RNA binding proteins as reprogramming factors, highlighting the so far known mechanisms of their reprogramming action.
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2
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Burgardt R, Lambert D, Heuwieser C, Sack M, Wagner G, Weinberg Z, Wachter A. Positioning of pyrimidine motifs around cassette exons defines their PTB-dependent splicing in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:2202-2218. [PMID: 38578875 DOI: 10.1111/tpj.16739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 03/14/2024] [Indexed: 04/07/2024]
Abstract
Alternative splicing (AS) is a complex process that generates transcript variants from a single pre-mRNA and is involved in numerous biological functions. Many RNA-binding proteins are known to regulate AS; however, little is known about the underlying mechanisms, especially outside the mammalian clade. Here, we show that polypyrimidine tract binding proteins (PTBs) from Arabidopsis thaliana regulate AS of cassette exons via pyrimidine (Py)-rich motifs close to the alternative splice sites. Mutational studies on three PTB-dependent cassette exon events revealed that only some of the Py motifs in this region are critical for AS. Moreover, in vitro binding of PTBs did not reflect a motif's impact on AS in vivo. Our mutational studies and bioinformatic investigation of all known PTB-regulated cassette exons from A. thaliana and human suggested that the binding position of PTBs relative to a cassette exon defines whether its inclusion or skipping is induced. Accordingly, exon skipping is associated with a higher frequency of Py stretches within the cassette exon, and in human also upstream of it, whereas exon inclusion is characterized by increased Py motif occurrence downstream of said exon. Enrichment of Py motifs downstream of PTB-activated 5' splice sites is also seen for PTB-dependent intron removal and alternative 5' splice site events from A. thaliana, suggesting this is a common step of exon definition. In conclusion, the position-dependent AS regulatory mechanism by PTB homologs has been conserved during the separate evolution of plants and mammals, while other critical features, in particular intron length, have considerably changed.
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Affiliation(s)
- Rica Burgardt
- Institute for Molecular Physiology (imP), University of Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
| | - Dorothee Lambert
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany
| | - Christina Heuwieser
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany
| | - Maximilian Sack
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107, Leipzig, Germany
| | - Gabriele Wagner
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany
| | - Zasha Weinberg
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107, Leipzig, Germany
| | - Andreas Wachter
- Institute for Molecular Physiology (imP), University of Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany
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3
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Bak M, van Nimwegen E, Kouzel IU, Gur T, Schmidt R, Zavolan M, Gruber AJ. MAPP unravels frequent co-regulation of splicing and polyadenylation by RNA-binding proteins and their dysregulation in cancer. Nat Commun 2024; 15:4110. [PMID: 38750024 PMCID: PMC11096328 DOI: 10.1038/s41467-024-48046-1] [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: 06/12/2023] [Accepted: 04/15/2024] [Indexed: 05/18/2024] Open
Abstract
Maturation of eukaryotic pre-mRNAs via splicing and polyadenylation is modulated across cell types and conditions by a variety of RNA-binding proteins (RBPs). Although there exist over 1,500 RBPs in human cells, their binding motifs and functions still remain to be elucidated, especially in the complex environment of tissues and in the context of diseases. To overcome the lack of methods for the systematic and automated detection of sequence motif-guided pre-mRNA processing regulation from RNA sequencing (RNA-Seq) data we have developed MAPP (Motif Activity on Pre-mRNA Processing). Applying MAPP to RBP knock-down experiments reveals that many RBPs regulate both splicing and polyadenylation of nascent transcripts by acting on similar sequence motifs. MAPP not only infers these sequence motifs, but also unravels the position-dependent impact of the RBPs on pre-mRNA processing. Interestingly, all investigated RBPs that act on both splicing and 3' end processing exhibit a consistently repressive or activating effect on both processes, providing a first glimpse on the underlying mechanism. Applying MAPP to normal and malignant brain tissue samples unveils that the motifs bound by the PTBP1 and RBFOX RBPs coordinately drive the oncogenic splicing program active in glioblastomas demonstrating that MAPP paves the way for characterizing pre-mRNA processing regulators under physiological and pathological conditions.
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Affiliation(s)
- Maciej Bak
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
- Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Erik van Nimwegen
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
- Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Ian U Kouzel
- Department of Biology, University of Konstanz, D-78464, Konstanz, Germany
| | - Tamer Gur
- Department of Biology, University of Konstanz, D-78464, Konstanz, Germany
| | - Ralf Schmidt
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
- Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Mihaela Zavolan
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
- Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Andreas J Gruber
- Department of Biology, University of Konstanz, D-78464, Konstanz, Germany.
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4
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Nazim M, Lin CH, Feng AC, Xiao W, Yeom KH, Li M, Daly AE, Tan X, Vu H, Ernst J, Carey MF, Smale ST, Black DL. Alternative splicing of a chromatin modifier alters the transcriptional regulatory programs of stem cell maintenance and neuronal differentiation. Cell Stem Cell 2024; 31:754-771.e6. [PMID: 38701759 PMCID: PMC11126784 DOI: 10.1016/j.stem.2024.04.001] [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: 09/06/2023] [Revised: 01/24/2024] [Accepted: 04/01/2024] [Indexed: 05/05/2024]
Abstract
Development of embryonic stem cells (ESCs) into neurons requires intricate regulation of transcription, splicing, and translation, but how these processes interconnect is not understood. We found that polypyrimidine tract binding protein 1 (PTBP1) controls splicing of DPF2, a subunit of BRG1/BRM-associated factor (BAF) chromatin remodeling complexes. Dpf2 exon 7 splicing is inhibited by PTBP1 to produce the DPF2-S isoform early in development. During neuronal differentiation, loss of PTBP1 allows exon 7 inclusion and DPF2-L expression. Different cellular phenotypes and gene expression programs were induced by these alternative DPF2 isoforms. We identified chromatin binding sites enriched for each DPF2 isoform, as well as sites bound by both. In ESC, DPF2-S preferential sites were bound by pluripotency factors. In neuronal progenitors, DPF2-S sites were bound by nuclear factor I (NFI), while DPF2-L sites were bound by CCCTC-binding factor (CTCF). DPF2-S sites exhibited enhancer modifications, while DPF2-L sites showed promoter modifications. Thus, alternative splicing redirects BAF complex targeting to impact chromatin organization during neuronal development.
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Affiliation(s)
- Mohammad Nazim
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Chia-Ho Lin
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - An-Chieh Feng
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Wen Xiao
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Kyu-Hyeon Yeom
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Mulin Li
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Allison E Daly
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Xianglong Tan
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Ha Vu
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Jason Ernst
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Michael F Carey
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Stephen T Smale
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA.
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5
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Moreno-Aguilera M, Neher AM, Mendoza MB, Dodel M, Mardakheh FK, Ortiz R, Gallego C. KIS counteracts PTBP2 and regulates alternative exon usage in neurons. eLife 2024; 13:e96048. [PMID: 38597390 PMCID: PMC11045219 DOI: 10.7554/elife.96048] [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: 01/12/2024] [Accepted: 04/09/2024] [Indexed: 04/11/2024] Open
Abstract
Alternative RNA splicing is an essential and dynamic process in neuronal differentiation and synapse maturation, and dysregulation of this process has been associated with neurodegenerative diseases. Recent studies have revealed the importance of RNA-binding proteins in the regulation of neuronal splicing programs. However, the molecular mechanisms involved in the control of these splicing regulators are still unclear. Here, we show that KIS, a kinase upregulated in the developmental brain, imposes a genome-wide alteration in exon usage during neuronal differentiation in mice. KIS contains a protein-recognition domain common to spliceosomal components and phosphorylates PTBP2, counteracting the role of this splicing factor in exon exclusion. At the molecular level, phosphorylation of unstructured domains within PTBP2 causes its dissociation from two co-regulators, Matrin3 and hnRNPM, and hinders the RNA-binding capability of the complex. Furthermore, KIS and PTBP2 display strong and opposing functional interactions in synaptic spine emergence and maturation. Taken together, our data uncover a post-translational control of splicing regulators that link transcriptional and alternative exon usage programs in neuronal development.
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Affiliation(s)
| | - Alba M Neher
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Mónica B Mendoza
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Martin Dodel
- Barts Cancer Institute, Queen Mary University of LondonLondonUnited Kingdom
| | - Faraz K Mardakheh
- Barts Cancer Institute, Queen Mary University of LondonLondonUnited Kingdom
| | - Raúl Ortiz
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Carme Gallego
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
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Li Q, Zhang W, Qiao XY, Liu C, Dao JJ, Qiao CM, Cui C, Shen YQ, Zhao WJ. Reducing polypyrimidine tract‑binding protein 1 fails to promote neuronal transdifferentiation on HT22 and mouse astrocyte cells under physiological conditions. Exp Ther Med 2024; 27:72. [PMID: 38234625 PMCID: PMC10792410 DOI: 10.3892/etm.2023.12360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/27/2023] [Indexed: 01/19/2024] Open
Abstract
In contrast to prior findings that have illustrated the conversion of non-neuronal cells into functional neurons through the specific targeting of polypyrimidine tract-binding protein 1 (PTBP1), accumulated evidence suggests the impracticality of inducing neuronal transdifferentiation through suppressing PTBP1 expression in pathological circumstances. Therefore, the present study explored the effect of knocking down PTBP1 under physiological conditions on the transdifferentiation of mouse hippocampal neuron HT22 cells and mouse astrocyte (MA) cells. A total of 20 µM negative control small interfering (si)RNA and siRNA targeting PTBP1 were transfected into HT22 and MA cells using Lipo8000™ for 3 and 5 days, respectively. The expression of early neuronal marker βIII-Tubulin and mature neuronal markers NeuN and microtubule-associated protein 2 (MAP2) were detected using western blotting. In addition, βIII-tubulin, NeuN and MAP2 were labeled with immunofluorescence staining to evaluate neuronal cell differentiation in response to PTBP1 downregulation. Under physiological conditions, no significant changes in the expression of βIII-Tubulin, NeuN and MAP2 were found after 3 and 5 days of knockdown of PTBP1 protein in both HT22 and MA cells. In addition, the immunofluorescence staining results showed no apparent transdifferentiation in maker levels and morphology. The results suggested that the knockdown of PTBP1 failed to induce neuronal differentiation under physiological conditions.
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Affiliation(s)
- Qian Li
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Wei Zhang
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
- Department of Pathogen Biology, Guizhou Nursing Vocational College, Guiyang, Guizhou 550081, P.R. China
| | - Xin-Yu Qiao
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Chong Liu
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Ji-Ji Dao
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Chen-Meng Qiao
- Department of Neurodegeneration and Neuroinjury, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Chun Cui
- Department of Neurodegeneration and Neuroinjury, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Yan-Qin Shen
- Department of Neurodegeneration and Neuroinjury, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Wei-Jiang Zhao
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
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7
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Sato J, Satoh Y, Yamamoto T, Watanabe T, Matsubara S, Satake H, Kimura AP. PTBP2 binds to a testis-specific long noncoding RNA, Tesra, and activates transcription of the Prss42/Tessp-2 gene. Gene 2024; 893:147907. [PMID: 37858745 DOI: 10.1016/j.gene.2023.147907] [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: 08/11/2023] [Revised: 09/22/2023] [Accepted: 10/16/2023] [Indexed: 10/21/2023]
Abstract
Long noncoding RNAs (lncRNAs) have recently been proved to be functional in the testis. Tesra, a testis-specific lncRNA, was suggested to activate the transcription of Prss42/Tessp-2, a gene that is involved in meiotic progression, in mouse spermatocytes. To reveal the molecular mechanism underlying the activation, we searched for Tesra-binding proteins by a Ribotrap assay followed by LC-MS/MS analysis and identified polypyrimidine tract binding protein 2 (PTBP2) as a candidate. Analysis of public RNA-seq data and our qRT-PCR results indicated that Ptbp2 mRNA showed an expression pattern similar to the expression patterns of Tesra and Prss42/Tessp-2 during testis development. Moreover, PTBP2 was found to be associated with Tesra in testicular germ cells by RNA immunoprecipitation. To evaluate the effect of PTBP2 on the Prss42/Tessp-2 promoter, we established an in vitro reporter gene assay system in which Tesra expression could be induced by the Tet-on system and thereby Prss42/Tessp-2 promoter activity could be increased. In this system, the Prss42/Tessp-2 promoter activity was significantly decreased by the knockdown of PTBP2. These results suggest that PTBP2 contributes to Prss42/Tessp-2 transcriptional activation by Tesra in spermatocytes. The finding provides a precious example of a molecular mechanism of testis lncRNA functioning in spermatogenesis.
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Affiliation(s)
- Josei Sato
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Yui Satoh
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Takehiro Yamamoto
- Department of Biochemistry, School of Medicine, Keio University, Tokyo, Japan
| | - Takehiro Watanabe
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Shin Matsubara
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Atsushi P Kimura
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan; Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan.
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8
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Zhu B, Fisher E, Li L, Zhong P, Yan Z, Feng J. PTBP2 attenuation facilitates fibroblast to neuron conversion by promoting alternative splicing of neuronal genes. Stem Cell Reports 2023; 18:2268-2282. [PMID: 37832540 PMCID: PMC10679656 DOI: 10.1016/j.stemcr.2023.09.012] [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: 10/27/2022] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
The direct conversion of human skin fibroblasts to neurons has a low efficiency and unclear mechanism. Here, we show that the knockdown of PTBP2 significantly enhanced the transdifferentiation induced by ASCL1, MIR9/9∗-124, and p53 shRNA (AMp) to generate mostly GABAergic neurons. Longitudinal RNA sequencing analyses identified the continuous induction of many RNA splicing regulators. Among these, the knockdown of RBFOX3 (NeuN), significantly abrogated the transdifferentiation. Overexpression of RBFOX3 significantly enhanced the conversion induced by AMp; the enhancement was occluded by PTBP2 knockdown. We found that PTBP2 attenuation significantly favored neuron-specific alternative splicing (AS) of many genes involved in synaptic transmission, signal transduction, and axon formation. RBFOX3 knockdown significantly reversed the effect, while RBFOX3 overexpression occluded the enhancement. The study reveals the critical role of neuron-specific AS in the direct conversion of human skin fibroblasts to neurons by showing that PTBP2 attenuation enhances this mechanism in concert with RBFOX3.
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Affiliation(s)
- Binglin Zhu
- Veterans Affairs Western New York Healthcare System, Buffalo, NY 14215, USA; Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Emily Fisher
- Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Li Li
- Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Ping Zhong
- Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Zhen Yan
- Veterans Affairs Western New York Healthcare System, Buffalo, NY 14215, USA; Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Jian Feng
- Veterans Affairs Western New York Healthcare System, Buffalo, NY 14215, USA; Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY 14203, USA.
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9
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Liang R, Wang L, Yang Q, Xu Q, Sun S, Zhou H, Zhao M, Gao J, Zheng C, Yang J, Ming D. Time-course adaptive changes in hippocampal transcriptome and synaptic function induced by simulated microgravity associated with cognition. Front Cell Neurosci 2023; 17:1275771. [PMID: 37868195 PMCID: PMC10585108 DOI: 10.3389/fncel.2023.1275771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/18/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction The investigation of cognitive function in microgravity, both short-term and long-term, remains largely descriptive. And the underlying mechanisms of the changes over time remain unclear. Methods Behavioral tests, electrophysiological recording, and RNA sequencing were used to observe differences in behavior, synaptic plasticity, and gene expression. Results Initially, we measured the performance of spatial cognition exposed to long-term simulated microgravity (SM). Both working memory and advanced cognitive abilities were enhanced. Somewhat surprisingly, the synaptic plasticity of the hippocampal CA3-CA1 synapse was impaired. To gain insight into the mechanism of changing regularity over time, transcriptome sequencing in the hippocampus was performed. The analysis identified 20 differentially expressed genes (DEGs) in the hippocampus after short-term modeling, 19 of which were up-regulated. Gene Ontology (GO) analysis showed that these up-regulated genes were mainly enriched in synaptic-related processes, such as Stxbp5l and Epha6. This might be related to the enhancement of working memory performance under short-term SM exposure. Under exposure to long-term SM, 7 DEGs were identified in the hippocampus, all of which were up-regulated and related to oxidative stress and metabolism, such as Depp1 and Lrg1. Compensatory effects occurred with increased modeling time. Discussion To sum up, our current research indicates that the cognitive function under SM exposure is consistently maintained or potentially even being enhanced over both short and long durations. The underlying mechanisms are intricate and potentially linked to the differential expression of hippocampal-associated genes and alterations in synaptic function, with these effects being time-dependent. The present study will lay the experimental and theoretical foundation of the multi-level mechanism of cognitive function under space flight.
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Affiliation(s)
- Rong Liang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Ling Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin, China
- Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin, China
| | - Qing Yang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Qing Xu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Shufan Sun
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Haichen Zhou
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Meiling Zhao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Jing Gao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Chenguang Zheng
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin, China
- Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin, China
| | - Jiajia Yang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin, China
- Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin, China
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin, China
- Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin, China
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10
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Yao F, Huang S, Liu J, Tan C, Xu M, Wang D, Huang M, Zhu Y, Huang X, He S. Deletion of ARGLU1 causes global defects in alternative splicing in vivo and mouse cortical malformations primarily via apoptosis. Cell Death Dis 2023; 14:543. [PMID: 37612280 PMCID: PMC10447433 DOI: 10.1038/s41419-023-06071-w] [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: 02/14/2023] [Revised: 08/01/2023] [Accepted: 08/15/2023] [Indexed: 08/25/2023]
Abstract
Haploinsufficient mutation in arginine and glutamine-rich protein 1 (Arglu1), a newly identified pre-mRNA splicing regulator, may be linked to neural developmental disorders associated with mental retardation and epilepsy in human patients, but the underlying causes remain elusive. Here we show that ablation of Arglu1 promotes radial glial cell (RG) detachment from the ventricular zone (VZ), leading to ectopic localized RGs in the mouse embryonic cortex. Although they remain proliferative, ectopic progenitors, as well as progenitors in the VZ, exhibit prolonged mitosis, p53 upregulation and cell apoptosis, leading to reduced neuron production, neuronal loss and microcephaly. RNA seq analysis reveals widespread changes in alternative splicing in the mutant mouse embryonic cortex, preferentially affecting genes involved in neuronal functions. Mdm2 and Mdm4 are found to be alternatively spliced at the exon 3 and exon 5 respectively, leading to absence of the p53-binding domain and nonsense-mediated mRNA decay (NMD) and thus relieve inhibition of p53. Removal of p53 largely rescues the microcephaly caused by deletion of Arglu1. Our findings provide mechanistic insights into cortical malformations of human patients with Arglu1 haploinsufficient mutation.
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Affiliation(s)
- Fenyong Yao
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
| | - Shisheng Huang
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jiahui Liu
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
| | - Chunhua Tan
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
| | - Mengqi Xu
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
| | - Dengkui Wang
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
| | - Maoqing Huang
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
| | - Yiyao Zhu
- School of Information Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China
| | - Xingxu Huang
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China.
| | - Shuijin He
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, 201210, Shanghai, China.
- Shanghai Clinical Research and Trial Center, 201210, Shanghai, China.
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11
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Kim JJ, Sayed ME, Ahn A, Slusher AL, Ying JY, Ludlow AT. Dynamics of TERT regulation via alternative splicing in stem cells and cancer cells. PLoS One 2023; 18:e0289327. [PMID: 37531400 PMCID: PMC10395990 DOI: 10.1371/journal.pone.0289327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/17/2023] [Indexed: 08/04/2023] Open
Abstract
Part of the regulation of telomerase activity includes the alternative splicing (AS) of the catalytic subunit telomerase reverse transcriptase (TERT). Although a therapeutic window for telomerase/TERT inhibition exists between cancer cells and somatic cells, stem cells express TERT and rely on telomerase activity for physiological replacement of cells. Therefore, identifying differences in TERT regulation between stem cells and cancer cells is essential for developing telomerase inhibition-based cancer therapies that reduce damage to stem cells. In this study, we measured TERT splice variant expression and telomerase activity in induced pluripotent stem cells (iPSCs), neural progenitor cells (NPCs), and non-small cell lung cancer cells (NSCLC, Calu-6 cells). We observed that a NOVA1-PTBP1-PTBP2 axis regulates TERT alternative splicing (AS) in iPSCs and their differentiation into NPCs. We also found that splice-switching of TERT, which regulates telomerase activity, is induced by different cell densities in stem cells but not cancer cells. Lastly, we identified cell type-specific splicing factors that regulate TERT AS. Overall, our findings represent an important step forward in understanding the regulation of TERT AS in stem cells and cancer cells.
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Affiliation(s)
- Jeongjin J Kim
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Mohammed E Sayed
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alexander Ahn
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Aaron L Slusher
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jeffrey Y Ying
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew T Ludlow
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
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12
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Watson A, Lako M. Retinal organoids provide unique insights into molecular signatures of inherited retinal disease throughout retinogenesis. J Anat 2023; 243:186-203. [PMID: 36177499 PMCID: PMC10335378 DOI: 10.1111/joa.13768] [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: 06/17/2022] [Revised: 09/06/2022] [Accepted: 09/06/2022] [Indexed: 10/14/2022] Open
Abstract
The demand for induced pluripotent stem cells (iPSC)-derived retinal organoid and retinal pigment epithelium (RPE) models for the modelling of inherited retinopathies has increased significantly in the last decade. These models are comparable with foetal retinas up until the later stages of retinogenesis, expressing all of the key neuronal markers necessary for retinal function. These models have proven to be invaluable in the understanding of retinogenesis, particular in the context of patient-specific diseases. Inherited retinopathies are infamously described as clinically and phenotypically heterogeneous, such that developing gene/mutation-specific animal models in each instance of retinal disease is not financially or ethically feasible. Further to this, many animal models are insufficient in the study of disease pathogenesis due to anatomical differences and failure to recapitulate human disease phenotypes. In contrast, iPSC-derived retinal models provide a high throughput platform which is physiologically relevant for studying human health and disease. They also serve as a platform for drug screening, gene therapy approaches and in vitro toxicology of novel therapeutics in pre-clinical studies. One unique characteristic of stem cell-derived retinal models is the ability to mimic in vivo retinogenesis, providing unparalleled insights into the effects of pathogenic mutations in cells of the developing retina, in a highly accessible way. This review aims to give the reader an overview of iPSC-derived retinal organoids and/or RPE in the context of disease modelling of several inherited retinopathies including Retinitis Pigmentosa, Stargardt disease and Retinoblastoma. We describe the ability of each model to recapitulate in vivo disease phenotypes, validate previous findings from animal models and identify novel pathomechanisms that underpin individual IRDs.
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Affiliation(s)
- Avril Watson
- Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Majlinda Lako
- Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
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13
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Verdile V, Riccioni V, Guerra M, Ferrante G, Sette C, Valle C, Ferri A, Paronetto MP. An impaired splicing program underlies differentiation defects in hSOD1 G93A neural progenitor cells. Cell Mol Life Sci 2023; 80:236. [PMID: 37524863 PMCID: PMC11072603 DOI: 10.1007/s00018-023-04893-7] [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: 03/07/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 08/02/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is an adult devastating neurodegenerative disease characterized by the loss of upper and lower motor neurons (MNs), resulting in progressive paralysis and death. Genetic animal models of ALS have highlighted dysregulation of synaptic structure and function as a pathogenic feature of ALS-onset and progression. Alternative pre-mRNA splicing (AS), which allows expansion of the coding power of genomes by generating multiple transcript isoforms from each gene, is widely associated with synapse formation and functional specification. Deciphering the link between aberrant splicing regulation and pathogenic features of ALS could pave the ground for novel therapeutic opportunities. Herein, we found that neural progenitor cells (NPCs) derived from the hSOD1G93A mouse model of ALS displayed increased proliferation and propensity to differentiate into neurons. In parallel, hSOD1G93A NPCs showed impaired splicing patterns in synaptic genes, which could contribute to the observed phenotype. Remarkably, master splicing regulators of the switch from stemness to neural differentiation are de-regulated in hSOD1G93A NPCs, thus impacting the differentiation program. Our data indicate that hSOD1G93A mutation impacts on neurogenesis by increasing the NPC pool in the developing mouse cortex and affecting their intrinsic properties, through the establishment of a specific splicing program.
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Affiliation(s)
- Veronica Verdile
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 6, 00135, Rome, Italy
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
| | - Veronica Riccioni
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
| | - Marika Guerra
- Section of Human Anatomy, Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Gabriele Ferrante
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
| | - Claudio Sette
- Section of Human Anatomy, Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, 00168, Rome, Italy
| | - Cristiana Valle
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
- Institute of Translational Pharmacology (IFT), Consiglio Nazionale delle Ricerche (CNR), 00133, Rome, Italy
| | - Alberto Ferri
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
- Institute of Translational Pharmacology (IFT), Consiglio Nazionale delle Ricerche (CNR), 00133, Rome, Italy
| | - Maria Paola Paronetto
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 6, 00135, Rome, Italy.
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy.
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14
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Salehi S, Zare A, Prezza G, Bader J, Schneider C, Fischer U, Meissner F, Mann M, Briese M, Sendtner M. Cytosolic Ptbp2 modulates axon growth in motoneurons through axonal localization and translation of Hnrnpr. Nat Commun 2023; 14:4158. [PMID: 37438340 DOI: 10.1038/s41467-023-39787-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 06/28/2023] [Indexed: 07/14/2023] Open
Abstract
The neuronal RNA-binding protein Ptbp2 regulates neuronal differentiation by modulating alternative splicing programs in the nucleus. Such programs contribute to axonogenesis by adjusting the levels of protein isoforms involved in axon growth and branching. While its functions in alternative splicing have been described in detail, cytosolic roles of Ptbp2 for axon growth have remained elusive. Here, we show that Ptbp2 is located in the cytosol including axons and growth cones of motoneurons, and that depletion of cytosolic Ptbp2 affects axon growth. We identify Ptbp2 as a major interactor of the 3' UTR of Hnrnpr mRNA encoding the RNA-binding protein hnRNP R. Axonal localization of Hnrnpr mRNA and local synthesis of hnRNP R protein are strongly reduced when Ptbp2 is depleted, leading to defective axon growth. Ptbp2 regulates hnRNP R translation by mediating the association of Hnrnpr with ribosomes in a manner dependent on the translation factor eIF5A2. Our data thus suggest a mechanism whereby cytosolic Ptbp2 modulates axon growth by fine-tuning the mRNA transport and local synthesis of an RNA-binding protein.
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Affiliation(s)
- Saeede Salehi
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Abdolhossein Zare
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Gianluca Prezza
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Wuerzburg, Germany
| | - Jakob Bader
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Cornelius Schneider
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Utz Fischer
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Felix Meissner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
- Experimental Systems Immunology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Institute of Innate Immunity, Department of Systems Immunology and Proteomics, Medical Faculty, University of Bonn, Bonn, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
- NNF Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Briese
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
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15
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Fu XD, Mobley WC. Therapeutic Potential of PTB Inhibition Through Converting Glial Cells to Neurons in the Brain. Annu Rev Neurosci 2023; 46:145-165. [PMID: 37428606 DOI: 10.1146/annurev-neuro-083022-113120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Cell replacement therapy represents a promising approach for treating neurodegenerative diseases. Contrary to the common addition strategy to generate new neurons from glia by overexpressing a lineage-specific transcription factor(s), a recent study introduced a subtraction strategy by depleting a single RNA-binding protein, Ptbp1, to convert astroglia to neurons not only in vitro but also in the brain. Given its simplicity, multiple groups have attempted to validate and extend this attractive approach but have met with difficulty in lineage tracing newly induced neurons from mature astrocytes, raising the possibility of neuronal leakage as an alternative explanation for apparent astrocyte-to-neuron conversion. This review focuses on the debate over this critical issue. Importantly, multiple lines of evidence suggest that Ptbp1 depletion can convert a selective subpopulation of glial cells into neurons and, via this and other mechanisms, reverse deficits in a Parkinson's disease model, emphasizing the importance of future efforts in exploring this therapeutic strategy.
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Affiliation(s)
- Xiang-Dong Fu
- Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China;
| | - William C Mobley
- Department of Neuroscience, University of California, San Diego, La Jolla, California, USA;
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16
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Wang Y, Xia Y, Kou L, Yin S, Chi X, Li J, Sun Y, Wu J, Zhou Q, Zou W, Jin Z, Huang J, Xiong N, Wang T. Astrocyte-to-neuron reprogramming and crosstalk in the treatment of Parkinson's disease. Neurobiol Dis 2023:106224. [PMID: 37433411 DOI: 10.1016/j.nbd.2023.106224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/24/2023] [Accepted: 07/07/2023] [Indexed: 07/13/2023] Open
Abstract
Parkinson's disease (PD) is currently the fastest growing disabling neurological disorder worldwide, with motor and non-motor symptoms being its main clinical manifestations. The primary pathological features include a reduction in the number of dopaminergic neurons in the substantia nigra and decrease in dopamine levels in the nigrostriatal pathway. Existing treatments only alleviate clinical symptoms and do not stop disease progression; slowing down the loss of dopaminergic neurons and stimulating their regeneration are emerging therapies. Preclinical studies have demonstrated that transplantation of dopamine cells generated from human embryonic or induced pluripotent stem cells can restore the loss of dopamine. However, the application of cell transplantation is limited owing to ethical controversies and the restricted source of cells. Until recently, the reprogramming of astrocytes to replenish lost dopaminergic neurons has provided a promising alternative therapy for PD. In addition, repair of mitochondrial perturbations, clearance of damaged mitochondria in astrocytes, and control of astrocyte inflammation may be extensively neuroprotective and beneficial against chronic neuroinflammation in PD. Therefore, this review primarily focuses on the progress and remaining issues in astrocyte reprogramming using transcription factors (TFs) and miRNAs, as well as exploring possible new targets for treating PD by repairing astrocytic mitochondria and reducing astrocytic inflammation.
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Affiliation(s)
- Yiming Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yun Xia
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Liang Kou
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Sijia Yin
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xiaosa Chi
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jingwen Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yadi Sun
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jiawei Wu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Qiulu Zhou
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Wenkai Zou
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Zongjie Jin
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jinsha Huang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Nian Xiong
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Tao Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
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17
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Sebastian R, Jin K, Pavon N, Bansal R, Potter A, Song Y, Babu J, Gabriel R, Sun Y, Aronow B, Pak C. Schizophrenia-associated NRXN1 deletions induce developmental-timing- and cell-type-specific vulnerabilities in human brain organoids. Nat Commun 2023; 14:3770. [PMID: 37355690 PMCID: PMC10290702 DOI: 10.1038/s41467-023-39420-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 06/13/2023] [Indexed: 06/26/2023] Open
Abstract
De novo mutations and copy number deletions in NRXN1 (2p16.3) pose a significant risk for schizophrenia (SCZ). It is unclear how NRXN1 deletions impact cortical development in a cell type-specific manner and disease background modulates these phenotypes. Here, we leveraged human pluripotent stem cell-derived forebrain organoid models carrying NRXN1 heterozygous deletions in isogenic and SCZ patient genetic backgrounds and conducted single-cell transcriptomic analysis over the course of brain organoid development from 3 weeks to 3.5 months. Intriguingly, while both deletions similarly impacted molecular pathways associated with ubiquitin-proteasome system, alternative splicing, and synaptic signaling in maturing glutamatergic and GABAergic neurons, SCZ-NRXN1 deletions specifically perturbed developmental trajectories of early neural progenitors and accumulated disease-specific transcriptomic signatures. Using calcium imaging, we found that both deletions led to long-lasting changes in spontaneous and synchronous neuronal networks, implicating synaptic dysfunction. Our study reveals developmental-timing- and cell-type-dependent actions of NRXN1 deletions in unique genetic contexts.
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Affiliation(s)
- Rebecca Sebastian
- Graduate Program in Neuroscience & Behavior, UMass Amherst, Amherst, MA, 01003, USA
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA, 01003, USA
| | - Kang Jin
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
- Department of Biomedical Informatics, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Narciso Pavon
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA, 01003, USA
| | - Ruby Bansal
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA, 01003, USA
| | - Andrew Potter
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Yoonjae Song
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA, 01003, USA
| | - Juliana Babu
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA, 01003, USA
| | - Rafael Gabriel
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA, 01003, USA
| | - Yubing Sun
- Department of Mechanical and Industrial Engineering, UMass Amherst, Amherst, MA, 01003, USA
| | - Bruce Aronow
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
- Department of Biomedical Informatics, University of Cincinnati, Cincinnati, OH, 45229, USA
- Department of Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, 45221, USA
- Department of Pediatrics, University of Cincinnati School of Medicine, Cincinnati, OH, 45256, USA
| | - ChangHui Pak
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA, 01003, USA.
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18
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Dawicki-McKenna JM, Felix AJ, Waxman EA, Cheng C, Amado DA, Ranum PT, Bogush A, Dungan LV, Maguire JA, Gagne AL, Heller EA, French DL, Davidson BL, Prosser BL. Mapping PTBP2 binding in human brain identifies SYNGAP1 as a target for therapeutic splice switching. Nat Commun 2023; 14:2628. [PMID: 37149717 PMCID: PMC10164156 DOI: 10.1038/s41467-023-38273-3] [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: 07/12/2022] [Accepted: 04/22/2023] [Indexed: 05/08/2023] Open
Abstract
Alternative splicing of neuronal genes is controlled partly by the coordinated action of polypyrimidine tract binding proteins (PTBPs). While PTBP1 is ubiquitously expressed, PTBP2 is predominantly neuronal. Here, we define the PTBP2 footprint in the human transcriptome using brain tissue and human induced pluripotent stem cell-derived neurons (iPSC-neurons). We map PTBP2 binding sites, characterize PTBP2-dependent alternative splicing events, and identify novel PTBP2 targets including SYNGAP1, a synaptic gene whose loss-of-function leads to a complex neurodevelopmental disorder. We find that PTBP2 binding to SYNGAP1 mRNA promotes alternative splicing and nonsense-mediated decay, and that antisense oligonucleotides (ASOs) that disrupt PTBP binding redirect splicing and increase SYNGAP1 mRNA and protein expression. In SYNGAP1 haploinsufficient iPSC-neurons generated from two patients, we show that PTBP2-targeting ASOs partially restore SYNGAP1 expression. Our data comprehensively map PTBP2-dependent alternative splicing in human neurons and cerebral cortex, guiding development of novel therapeutic tools to benefit neurodevelopmental disorders.
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Affiliation(s)
- Jennine M Dawicki-McKenna
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Alex J Felix
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Elisa A Waxman
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Congsheng Cheng
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Defne A Amado
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Paul T Ranum
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Alexey Bogush
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Lea V Dungan
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Jean Ann Maguire
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Alyssa L Gagne
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Elizabeth A Heller
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Deborah L French
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Beverly L Davidson
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
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19
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LaForce GR, Philippidou P, Schaffer AE. mRNA isoform balance in neuronal development and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1762. [PMID: 36123820 PMCID: PMC10024649 DOI: 10.1002/wrna.1762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/11/2022] [Accepted: 08/15/2022] [Indexed: 11/07/2022]
Abstract
Balanced mRNA isoform diversity and abundance are spatially and temporally regulated throughout cellular differentiation. The proportion of expressed isoforms contributes to cell type specification and determines key properties of the differentiated cells. Neurons are unique cell types with intricate developmental programs, characteristic cellular morphologies, and electrophysiological potential. Neuron-specific gene expression programs establish these distinctive cellular characteristics and drive diversity among neuronal subtypes. Genes with neuron-specific alternative processing are enriched in key neuronal functions, including synaptic proteins, adhesion molecules, and scaffold proteins. Despite the similarity of neuronal gene expression programs, each neuronal subclass can be distinguished by unique alternative mRNA processing events. Alternative processing of developmentally important transcripts alters coding and regulatory information, including interaction domains, transcript stability, subcellular localization, and targeting by RNA binding proteins. Fine-tuning of mRNA processing is essential for neuronal activity and maintenance. Thus, the focus of neuronal RNA biology research is to dissect the transcriptomic mechanisms that underlie neuronal homeostasis, and consequently, predispose neuronal subtypes to disease. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Geneva R LaForce
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Polyxeni Philippidou
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ashleigh E Schaffer
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
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20
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Morelli KH, Smargon AA, Yeo GW. Programmable macromolecule-based RNA-targeting therapies to treat human neurological disorders. RNA (NEW YORK, N.Y.) 2023; 29:489-497. [PMID: 36693761 PMCID: PMC10019361 DOI: 10.1261/rna.079519.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Disruptions in RNA processing play critical roles in the pathogenesis of neurological diseases. In this Perspective, we discuss recent progress in the development of RNA-targeting therapeutic modalities. We focus on progress, limitations, and opportunities in a new generation of therapies engineered from RNA binding proteins and other endogenous RNA regulatory macromolecules to treat human neurological disorders.
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Affiliation(s)
- Kathryn H Morelli
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92039, USA
| | - Aaron A Smargon
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92039, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92039, USA
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21
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Chen XD, Liu HL, Li S, Hu KB, Wu QY, Liao P, Wang HY, Long ZY, Lu XM, Wang YT. The latest role of nerve-specific splicing factor PTBP1 in the transdifferentiation of glial cells into neurons. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1740. [PMID: 35574699 DOI: 10.1002/wrna.1740] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/16/2022] [Accepted: 04/21/2022] [Indexed: 11/07/2022]
Abstract
Central nervous system injury diseases can cause the loss of many neurons, and it is difficult to regenerate. The field of regenerative medicine believes that supplementing the missing neurons may be an ideal method for nerve injury repair. Recent studies have found that down-regulation of polypyrimidine tract binding protein 1 (PTBP1) expression can make glial cells transdifferentiate into different types of neurons, which is expected to be an alternative therapy to restore neuronal function. This article summarized the research progress on the structure and biological function of the PTBP family, the mutual regulation of PTBP1 and PTBP2, their role in neurogenesis, and the latest research progress in targeting PTBP1 to mediate the transdifferentiation of glial cells into neurons, which may provide some new strategies and new ideas for the future treatment of central nervous system injury and neurodegenerative diseases. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
- Xing-Dong Chen
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China.,State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Hui-Lin Liu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Sen Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Kai-Bin Hu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Qing-Yun Wu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Ping Liao
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Hai-Yan Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Zai-Yun Long
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Xiu-Min Lu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Yong-Tang Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
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22
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Traunmüller L, Schulz J, Ortiz R, Feng H, Furlanis E, Gomez AM, Schreiner D, Bischofberger J, Zhang C, Scheiffele P. A cell-type-specific alternative splicing regulator shapes synapse properties in a trans-synaptic manner. Cell Rep 2023; 42:112173. [PMID: 36862556 PMCID: PMC10066595 DOI: 10.1016/j.celrep.2023.112173] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 12/07/2022] [Accepted: 02/12/2023] [Indexed: 03/03/2023] Open
Abstract
The specification of synaptic properties is fundamental for the function of neuronal circuits. "Terminal selector" transcription factors coordinate terminal gene batteries that specify cell-type-specific properties. Moreover, pan-neuronal splicing regulators have been implicated in directing neuronal differentiation. However, the cellular logic of how splicing regulators instruct specific synaptic properties remains poorly understood. Here, we combine genome-wide mapping of mRNA targets and cell-type-specific loss-of-function studies to uncover the contribution of the RNA-binding protein SLM2 to hippocampal synapse specification. Focusing on pyramidal cells and somatostatin (SST)-positive GABAergic interneurons, we find that SLM2 preferentially binds and regulates alternative splicing of transcripts encoding synaptic proteins. In the absence of SLM2, neuronal populations exhibit normal intrinsic properties, but there are non-cell-autonomous synaptic phenotypes and associated defects in a hippocampus-dependent memory task. Thus, alternative splicing provides a critical layer of gene regulation that instructs specification of neuronal connectivity in a trans-synaptic manner.
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Affiliation(s)
| | - Jan Schulz
- Department of Biomedicine, University of Basel, 4056 Basel, Switzerland
| | - Raul Ortiz
- Biozentrum of the University of Basel, 4056 Basel, Switzerland
| | - Huijuan Feng
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
| | | | - Andrea M Gomez
- Biozentrum of the University of Basel, 4056 Basel, Switzerland
| | | | | | - Chaolin Zhang
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
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23
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Molecular Mechanisms Involved in the Regulation of Neurodevelopment by miR-124. Mol Neurobiol 2023; 60:3569-3583. [PMID: 36840845 DOI: 10.1007/s12035-023-03271-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 02/04/2023] [Indexed: 02/26/2023]
Abstract
miR-124 is a miRNA predominantly expressed in the nervous system and accounts for more than a quarter of the total miRNAs in the brain. It regulates neurogenesis, neuronal differentiation, neuronal maturation, and synapse formation and is the most important miRNA in the brain. Furthermore, emerging evidence has suggested miR-124 may be associated with the pathogenesis of various neurodevelopmental and neuropsychiatric disorders. Here, we provide an overview of the role of miR-124 in neurodevelopment and the underling mechanisms, and finally, we prospect the significance of miR-124 research to the field of neuroscience.
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24
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Buen Abad Najar CF, Burra P, Yosef N, Lareau LF. Identifying cell state-associated alternative splicing events and their coregulation. Genome Res 2022; 32:gr.276109.121. [PMID: 35858747 PMCID: PMC9341514 DOI: 10.1101/gr.276109.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 06/01/2022] [Indexed: 11/25/2022]
Abstract
Alternative splicing shapes the transcriptome and contributes to each cell's unique identity, but single-cell RNA sequencing (scRNA-seq) has struggled to capture the impact of alternative splicing. We previously showed that low recovery of mRNAs from single cells led to erroneous conclusions about the cell-to-cell variability of alternative splicing. Here, we present a method, Psix, to confidently identify splicing that changes across a landscape of single cells, using a probabilistic model that is robust against the data limitations of scRNA-seq. Its autocorrelation-inspired approach finds patterns of alternative splicing that correspond to patterns of cell identity, such as cell type or developmental stage, without the need for explicit cell clustering, labeling, or trajectory inference. Applying Psix to data that follow the trajectory of mouse brain development, we identify exons whose alternative splicing patterns cluster into modules of coregulation. We show that the exons in these modules are enriched for binding by distinct neuronal splicing factors and that their changes in splicing correspond to changes in expression of these splicing factors. Thus, Psix reveals cell type-dependent splicing patterns and the wiring of the splicing regulatory networks that control them. Our new method will enable scRNA-seq analysis to go beyond transcription to understand the roles of post-transcriptional regulation in determining cell identity.
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Affiliation(s)
| | - Prakruthi Burra
- Center for Computational Biology, University of California, Berkeley, California 94720, USA
| | - Nir Yosef
- Center for Computational Biology, University of California, Berkeley, California 94720, USA
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, California 94720, USA
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts 02139, USA
- Chan Zuckerberg Biohub, San Francisco, California 94158, USA
| | - Liana F Lareau
- Center for Computational Biology, University of California, Berkeley, California 94720, USA
- Chan Zuckerberg Biohub, San Francisco, California 94158, USA
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
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25
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Wright CJ, Smith CWJ, Jiggins CD. Alternative splicing as a source of phenotypic diversity. Nat Rev Genet 2022; 23:697-710. [PMID: 35821097 DOI: 10.1038/s41576-022-00514-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2022] [Indexed: 12/27/2022]
Abstract
A major goal of evolutionary genetics is to understand the genetic processes that give rise to phenotypic diversity in multicellular organisms. Alternative splicing generates multiple transcripts from a single gene, enriching the diversity of proteins and phenotypic traits. It is well established that alternative splicing contributes to key innovations over long evolutionary timescales, such as brain development in bilaterians. However, recent developments in long-read sequencing and the generation of high-quality genome assemblies for diverse organisms has facilitated comparisons of splicing profiles between closely related species, providing insights into how alternative splicing evolves over shorter timescales. Although most splicing variants are probably non-functional, alternative splicing is nonetheless emerging as a dynamic, evolutionarily labile process that can facilitate adaptation and contribute to species divergence.
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Affiliation(s)
- Charlotte J Wright
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK. .,Department of Zoology, University of Cambridge, Cambridge, UK.
| | | | - Chris D Jiggins
- Department of Zoology, University of Cambridge, Cambridge, UK.
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26
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PTBP2 - a gene with relevance for both Anorexia nervosa and body weight regulation. Transl Psychiatry 2022; 12:241. [PMID: 35680849 PMCID: PMC9184595 DOI: 10.1038/s41398-022-02018-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/23/2022] [Accepted: 06/01/2022] [Indexed: 12/14/2022] Open
Abstract
Genetic factors are relevant for both eating disorders and body weight regulation. A recent genome-wide association study (GWAS) for anorexia nervosa (AN) detected eight genome-wide significant chromosomal loci. One of these loci, rs10747478, was also genome-wide and significantly associated with body mass index (BMI). The nearest coding gene is the Polypyrimidine Tract Binding Protein 2 gene (PTBP2). To detect mutations in PTBP2, Sanger sequencing of the coding region was performed in 192 female patients with AN (acute or recovered) and 191 children or adolescents with (extreme) obesity. Twenty-five variants were identified. Twenty-three of these were predicted to be pathogenic or functionally relevant in at least one in silico tool. Two novel synonymous variants (p.Ala77Ala and p.Asp195Asp), one intronic SNP (rs188987764), and the intronic deletion (rs561340981) located in the highly conserved region of PTBP2 may have functional consequences. Ten of 20 genes interacting with PTBP2 were studied for their impact on body weight regulation based on either previous functional studies or GWAS hits for body weight or BMI. In a GWAS for BMI (Pulit et al. 2018), the number of genome-wide significant associations at the PTBP2 locus was different between males (60 variants) and females (two variants, one of these also significant in males). More than 65% of these 61 variants showed differences in the effect size pertaining to BMI between sexes (absolute value of Z-score >2, two-sided p < 0.05). One LD block overlapping 5'UTR and all coding regions of PTBP2 comprises 56 significant variants in males. The analysis based on sex-stratified BMI GWAS summary statistics implies that PTBP2 may have a more pronounced effect on body weight regulation in males than in females.
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27
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Pina JM, Hernandez LA, Keppetipola NM. Polypyrimidine tract binding proteins PTBP1 and PTBP2 interact with distinct proteins under splicing conditions. PLoS One 2022; 17:e0263287. [PMID: 35113929 PMCID: PMC8812845 DOI: 10.1371/journal.pone.0263287] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 01/17/2022] [Indexed: 11/18/2022] Open
Abstract
RNA binding proteins play an important role in regulating alternative pre-mRNA splicing and in turn cellular gene expression. Polypyrimidine tract binding proteins, PTBP1 and PTBP2, are paralogous RNA binding proteins that play a critical role in the process of neuronal differentiation and maturation; changes in the concentration of PTBP proteins during neuronal development direct splicing changes in many transcripts that code for proteins critical for neuronal differentiation. How the two related proteins regulate different sets of neuronal exons is unclear. The distinct splicing activities of PTBP1 and PTBP2 can be recapitulated in an in vitro splicing system with the differentially regulated N1 exon of the c-src pre-mRNA. Here, we conducted experiments under these in vitro splicing conditions to identify PTBP1 and PTBP2 interacting partner proteins. Our results highlight that both PTBPs interact with proteins that participate in chromatin remodeling and transcription regulation. Our data reveal that PTBP1 interacts with many proteins involved in mRNA processing including splicing regulation while PTBP2 does not. Our results also highlight enzymes that can serve as potential "writers" and "erasers" in adding chemical modifications to the PTB proteins. Overall, our study highlights important differences in protein-protein interactions between the PTBP proteins under splicing conditions and supports a role for post-translational modifications in dictating their distinct splicing activities.
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Affiliation(s)
- Jeffrey M. Pina
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, CA, United States of America
| | - Luis A. Hernandez
- Department of Biological Sciences, California State University Fullerton, Fullerton, CA, United States of America
| | - Niroshika M. Keppetipola
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, CA, United States of America
- * E-mail:
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28
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Lachke SA. RNA-binding proteins and post-transcriptional regulation in lens biology and cataract: Mediating spatiotemporal expression of key factors that control the cell cycle, transcription, cytoskeleton and transparency. Exp Eye Res 2022; 214:108889. [PMID: 34906599 PMCID: PMC8792301 DOI: 10.1016/j.exer.2021.108889] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/29/2021] [Accepted: 12/05/2021] [Indexed: 01/03/2023]
Abstract
Development of the ocular lens - a transparent tissue capable of sustaining frequent shape changes for optimal focusing power - pushes the boundaries of what cells can achieve using the molecular toolkit encoded by their genomes. The mammalian lens contains broadly two types of cells, the anteriorly located monolayer of epithelial cells which, at the equatorial region of the lens, initiate differentiation into fiber cells that contribute to the bulk of the tissue. This differentiation program involves massive upregulation of select fiber cell-expressed RNAs and their subsequent translation into high amounts of proteins, such as crystallins. But intriguingly, fiber cells achieve this while also simultaneously undergoing significant morphological changes such as elongation - involving about 1000-fold length-wise increase - and migration, which requires modulation of cytoskeletal and cell adhesion factors. Adding further to the challenges, these molecular and cellular events have to be coordinated as fiber cells progress toward loss of their nuclei and organelles, which irreversibly compromises their potential for harnessing genetically hardwired information. A long-standing question is how processes downstream of signaling and transcription, which may also participate in feedback regulation, contribute toward orchestrating these cellular differentiation events in the lens. It is now becoming clear from findings over the past decade that post-transcriptional gene expression regulatory mechanisms are critical in controlling cellular proteomes and coordinating key processes in lens development and fiber cell differentiation. Indeed, RNA-binding proteins (RBPs) such as Caprin2, Celf1, Rbm24 and Tdrd7 have now been described in mediating post-transcriptional control over key factors (e.g. Actn2, Cdkn1a (p21Cip1), Cdkn1b (p27Kip1), various crystallins, Dnase2b, Hspb1, Pax6, Prox1, Sox2) that are variously involved in cell cycle, transcription, cytoskeleton maintenance and differentiation in the lens. Furthermore, deficiencies of these RBPs have been shown to result in various eye and lens defects and/or cataract. Because fiber cell differentiation in the lens occurs throughout life, the underlying regulatory mechanisms operational in development are expected to also be recruited for the maintenance of transparency in aged lenses. Indeed, in support of this, TDRD7 and CAPRIN2 loci have been linked to age-related cataract in humans. Here, I will review the role of key RBPs in the lens and their importance in understanding the pathology of lens defects. I will discuss advances in RBP-based gene expression control, in general, and the important challenges that need to be addressed in the lens to define the mechanisms that determine the epithelial and fiber cell proteome. Finally, I will also discuss in detail several key future directions including the application of bioinformatics approaches such as iSyTE to study RBP-based post-transcriptional gene expression control in the aging lens and in the context of age-related cataract.
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Affiliation(s)
- Salil A Lachke
- Department of Biological Sciences, University of Delaware, 105 The Green, Delaware Avenue, 236 Wolf Hall, Newark, DE, USA; Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE, 19716, USA.
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29
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Kim JH, Jeong K, Li J, Murphy JM, Vukadin L, Stone JK, Richard A, Tran J, Gillespie GY, Flemington EK, Sobol RW, Lim STS, Ahn EYE. SON drives oncogenic RNA splicing in glioblastoma by regulating PTBP1/PTBP2 switching and RBFOX2 activity. Nat Commun 2021; 12:5551. [PMID: 34548489 PMCID: PMC8455679 DOI: 10.1038/s41467-021-25892-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 09/01/2021] [Indexed: 12/15/2022] Open
Abstract
While dysregulation of RNA splicing has been recognized as an emerging target for cancer therapy, the functional significance of RNA splicing and individual splicing factors in brain tumors is poorly understood. Here, we identify SON as a master regulator that activates PTBP1-mediated oncogenic splicing while suppressing RBFOX2-mediated non-oncogenic neuronal splicing in glioblastoma multiforme (GBM). SON is overexpressed in GBM patients and SON knockdown causes failure in intron removal from the PTBP1 transcript, resulting in PTBP1 downregulation and inhibition of its downstream oncogenic splicing. Furthermore, SON forms a complex with hnRNP A2B1 and antagonizes RBFOX2, which leads to skipping of RBFOX2-targeted cassette exons, including the PTBP2 neuronal exon. SON knockdown inhibits proliferation and clonogenicity of GBM cells in vitro and significantly suppresses tumor growth in orthotopic xenografts in vivo. Collectively, our study reveals that SON-mediated RNA splicing is a GBM vulnerability, implicating SON as a potential therapeutic target in brain tumors.
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Affiliation(s)
- Jung-Hyun Kim
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Kyuho Jeong
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Jianfeng Li
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - James M Murphy
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Lana Vukadin
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Joshua K Stone
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
| | - Alexander Richard
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
| | - Johnny Tran
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
| | - G Yancey Gillespie
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Erik K Flemington
- Department of Pathology, Tulane University School of Medicine, Tulane Cancer Center, New Orleans, LA, USA
| | - Robert W Sobol
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA.
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL, USA.
| | - Ssang-Teak Steve Lim
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.
| | - Eun-Young Erin Ahn
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA.
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30
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Transcriptome programs involved in the development and structure of the cerebellum. Cell Mol Life Sci 2021; 78:6431-6451. [PMID: 34406416 PMCID: PMC8558292 DOI: 10.1007/s00018-021-03911-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 08/02/2021] [Indexed: 12/23/2022]
Abstract
In the past two decades, mounting evidence has modified the classical view of the cerebellum as a brain region specifically involved in the modulation of motor functions. Indeed, clinical studies and engineered mouse models have highlighted cerebellar circuits implicated in cognitive functions and behavior. Furthermore, it is now clear that insults occurring in specific time windows of cerebellar development can affect cognitive performance later in life and are associated with neurological syndromes, such as Autism Spectrum Disorder. Despite its almost homogenous cytoarchitecture, how cerebellar circuits form and function is not completely elucidated yet. Notably, the apparently simple neuronal organization of the cerebellum, in which Purkinje cells represent the only output, hides an elevated functional diversity even within the same neuronal population. Such complexity is the result of the integration of intrinsic morphogenetic programs and extracellular cues from the surrounding environment, which impact on the regulation of the transcriptome of cerebellar neurons. In this review, we briefly summarize key features of the development and structure of the cerebellum before focusing on the pathways involved in the acquisition of the cerebellar neuron identity. We focus on gene expression and mRNA processing programs, including mRNA methylation, trafficking and splicing, that are set in motion during cerebellar development and participate to its physiology. These programs are likely to add new layers of complexity and versatility that are fundamental for the adaptability of cerebellar neurons.
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31
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Abstract
Neurodegenerative diseases, characterized by progressive neural loss, have been some of the most challenging medical problems in aging societies. Treatment strategies such as symptom management have little impact on dis-ease progression, while intervention with specific disease mechanisms may only slow down disease progression. One therapeutic strategy that has the potential to reverse the disease phenotype is to replenish neurons and re-build the pathway lost to degeneration. Although it is generally believed that the central nervous system has lost the capability to regenerate, increasing evidence indicates that the brain is more plastic than previously thought, containing perhaps the biggest repertoire of cells with latent neurogenic programs in the body. This review focuses on key advances in generating new neurons through in situ neuronal reprogramming, which is tied to fun-damental questions regarding adult neurogenesis, cell source, and mecha-nisms for neuronal reprogramming, as well as the ability of new neurons to integrate into the existing circuitry. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Hao Qian
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093-0651, USA;
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093-0651, USA;
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32
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MiR-124 synergism with ELAVL3 enhances target gene expression to promote neuronal maturity. Proc Natl Acad Sci U S A 2021; 118:2015454118. [PMID: 34031238 DOI: 10.1073/pnas.2015454118] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neuron-enriched microRNAs (miRNAs), miR-9/9* and miR-124 (miR-9/9*-124), direct cell fate switching of human fibroblasts to neurons when ectopically expressed by repressing antineurogenic genes. How these miRNAs function after the repression of fibroblast genes for neuronal fate remains unclear. Here, we identified targets of miR-9/9*-124 as reprogramming cells activate the neuronal program and reveal the role of miR-124 that directly promotes the expression of its target genes associated with neuronal development and function. The mode of miR-124 as a positive regulator is determined by the binding of both AGO and a neuron-enriched RNA-binding protein, ELAVL3, to target transcripts. Although existing literature indicates that miRNA-ELAVL family protein interaction can result in either target gene up-regulation or down-regulation in a context-dependent manner, we specifically identified neuronal ELAVL3 as the driver for miR-124 target gene up-regulation in neurons. In primary human neurons, repressing miR-124 and ELAVL3 led to the down-regulation of genes involved in neuronal function and process outgrowth and cellular phenotypes of reduced inward currents and neurite outgrowth. Our results highlight the synergistic role between miR-124 and RNA-binding proteins to promote target gene regulation and neuronal function.
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33
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Li D, McIntosh CS, Mastaglia FL, Wilton SD, Aung-Htut MT. Neurodegenerative diseases: a hotbed for splicing defects and the potential therapies. Transl Neurodegener 2021; 10:16. [PMID: 34016162 PMCID: PMC8136212 DOI: 10.1186/s40035-021-00240-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/23/2021] [Indexed: 12/14/2022] Open
Abstract
Precursor messenger RNA (pre-mRNA) splicing is a fundamental step in eukaryotic gene expression that systematically removes non-coding regions (introns) and ligates coding regions (exons) into a continuous message (mature mRNA). This process is highly regulated and can be highly flexible through a process known as alternative splicing, which allows for several transcripts to arise from a single gene, thereby greatly increasing genetic plasticity and the diversity of proteome. Alternative splicing is particularly prevalent in neuronal cells, where the splicing patterns are continuously changing to maintain cellular homeostasis and promote neurogenesis, migration and synaptic function. The continuous changes in splicing patterns and a high demand on many cis- and trans-splicing factors contribute to the susceptibility of neuronal tissues to splicing defects. The resultant neurodegenerative diseases are a large group of disorders defined by a gradual loss of neurons and a progressive impairment in neuronal function. Several of the most common neurodegenerative diseases involve some form of splicing defect(s), such as Alzheimer's disease, Parkinson's disease and spinal muscular atrophy. Our growing understanding of RNA splicing has led to the explosion of research in the field of splice-switching antisense oligonucleotide therapeutics. Here we review our current understanding of the effects alternative splicing has on neuronal differentiation, neuronal migration, synaptic maturation and regulation, as well as the impact on neurodegenerative diseases. We will also review the current landscape of splice-switching antisense oligonucleotides as a therapeutic strategy for a number of common neurodegenerative disorders.
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Affiliation(s)
- Dunhui Li
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Craig Stewart McIntosh
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Frank Louis Mastaglia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Steve Donald Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - May Thandar Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia. .,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia.
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34
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Gourain V, Armant O, Lübke L, Diotel N, Rastegar S, Strähle U. Multi-Dimensional Transcriptome Analysis Reveals Modulation of Cholesterol Metabolism as Highly Integrated Response to Brain Injury. Front Neurosci 2021; 15:671249. [PMID: 34054419 PMCID: PMC8162057 DOI: 10.3389/fnins.2021.671249] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/16/2021] [Indexed: 12/14/2022] Open
Abstract
Zebrafish is an attractive model to investigate regeneration of the nervous system. Despite major progress in our understanding of the underlying processes, the transcriptomic changes are largely unknown. We carried out a computational analysis of the transcriptome of the regenerating telencephalon integrating changes in the expression of mRNAs, their splice variants and investigated the putative role of regulatory RNAs in the modulation of these transcriptional changes. Profound changes in the expression of genes and their splice variants engaged in many distinct processes were observed. Differential transcription and splicing are important processes in response to injury of the telencephalon. As exemplified by the coordinated regulation of the cholesterol synthesizing enzymes and transporters, the genome responded to injury of the telencephalon in a multi-tiered manner with distinct and interwoven changes in expression of enzymes, transporters and their regulatory molecules. This coordinated genomic response involved a decrease of the mRNA of the key transcription factor SREBF2, induction of microRNAs (miR-182, miR-155, miR-146, miR-31) targeting cholesterol genes, shifts in abundance of splice variants as well as regulation of long non-coding RNAs. Cholesterol metabolism appears to be switched from synthesis to relocation of cholesterol. Based on our in silico analyses, this switch involves complementary and synergistic inputs by different regulatory principles. Our studies suggest that adaptation of cholesterol metabolism is a key process involved in regeneration of the injured zebrafish brain.
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Affiliation(s)
- Victor Gourain
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.,UMR 1064 Centre de Recherche en Transplantation en Immunologie, Nantes, France
| | - Olivier Armant
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.,PSE-ENV/SRTE/LECO, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Cadarache, Saint-Paul-Lez-Durance, France
| | - Luisa Lübke
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Nicolas Diotel
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.,UMR 1188, Diabète Athérothrombose Thérapies Réunion Océan Indien CYROI, Saint-Denis, France
| | - Sepand Rastegar
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Uwe Strähle
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.,COS, University Heidelberg, Heidelberg, Germany
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35
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Naro C, Cesari E, Sette C. Splicing regulation in brain and testis: common themes for highly specialized organs. Cell Cycle 2021; 20:480-489. [PMID: 33632061 PMCID: PMC8018374 DOI: 10.1080/15384101.2021.1889187] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/17/2021] [Accepted: 02/07/2021] [Indexed: 12/26/2022] Open
Abstract
Expansion of the coding and regulatory capabilities of eukaryotic transcriptomes by alternative splicing represents one of the evolutionary forces underlying the increased structural complexity of metazoans. Brain and testes stand out as the organs that mostly exploit the potential of alternative splicing, thereby expressing the largest repertoire of splice variants. Herein, we will review organ-specific as well as common mechanisms underlying the high transcriptome complexity of these organs and discuss the impact exerted by this widespread alternative splicing regulation on the functionality and differentiation of brain and testicular cells.
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Affiliation(s)
- Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Eleonora Cesari
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
- Laboratory of Neuroembryology, IRCCS Fondazione Santa Lucia, Rome, Italy
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36
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Merlevede A, Legault EM, Drugge V, Barker RA, Drouin-Ouellet J, Olariu V. A quantitative model of cellular decision making in direct neuronal reprogramming. Sci Rep 2021; 11:1514. [PMID: 33452356 PMCID: PMC7810861 DOI: 10.1038/s41598-021-81089-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 01/01/2021] [Indexed: 12/25/2022] Open
Abstract
The direct reprogramming of adult skin fibroblasts to neurons is thought to be controlled by a small set of interacting gene regulators. Here, we investigate how the interaction dynamics between these regulating factors coordinate cellular decision making in direct neuronal reprogramming. We put forward a quantitative model of the governing gene regulatory system, supported by measurements of mRNA expression. We found that nPTB needs to feed back into the direct neural conversion network most likely via PTB in order to accurately capture quantitative gene interaction dynamics and correctly predict the outcome of various overexpression and knockdown experiments. This was experimentally validated by nPTB knockdown leading to successful neural conversion. We also proposed a novel analytical technique to dissect system behaviour and reveal the influence of individual factors on resulting gene expression. Overall, we demonstrate that computational analysis is a powerful tool for understanding the mechanisms of direct (neuronal) reprogramming, paving the way for future models that can help improve cell conversion strategies.
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Affiliation(s)
- Adriaan Merlevede
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, 223 62, Lund, Sweden
| | - Emilie M Legault
- Faculté de Pharmacie, Université de Montréal, Montreal, QC, H3T 1J4, Canada
| | - Viktor Drugge
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, 223 62, Lund, Sweden
| | - Roger A Barker
- Cambridge Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge, CB2 2PY, UK
| | | | - Victor Olariu
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, 223 62, Lund, Sweden.
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37
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Shah S, Richter JD. Do Fragile X Syndrome and Other Intellectual Disorders Converge at Aberrant Pre-mRNA Splicing? Front Psychiatry 2021; 12:715346. [PMID: 34566717 PMCID: PMC8460907 DOI: 10.3389/fpsyt.2021.715346] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Fragile X Syndrome is a neuro-developmental disorder caused by the silencing of the FMR1 gene, resulting in the loss of its protein product, FMRP. FMRP binds mRNA and represses general translation in the brain. Transcriptome analysis of the Fmr1-deficient mouse hippocampus reveals widespread dysregulation of alternative splicing of pre-mRNAs. Many of these aberrant splicing changes coincide with those found in post-mortem brain tissue from individuals with autism spectrum disorders (ASDs) as well as in mouse models of intellectual disability such as PTEN hamartoma syndrome (PHTS) and Rett Syndrome (RTT). These splicing changes could result from chromatin modifications (e.g., in FXS, RTT) and/or splicing factor alterations (e.g., PTEN, autism). Based on the identities of the RNAs that are mis-spliced in these disorders, it may be that they are at least partly responsible for some shared pathophysiological conditions. The convergence of splicing aberrations among these autism spectrum disorders might be crucial to understanding their underlying cognitive impairments.
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Affiliation(s)
- Sneha Shah
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Joel D Richter
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States
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38
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Rontani P, Perche O, Greetham L, Jullien N, Gepner B, Féron F, Nivet E, Erard-Garcia M. Impaired expression of the COSMOC/MOCOS gene unit in ASD patient stem cells. Mol Psychiatry 2021; 26:1606-1618. [PMID: 32327736 PMCID: PMC8159765 DOI: 10.1038/s41380-020-0728-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 03/17/2020] [Accepted: 04/03/2020] [Indexed: 12/16/2022]
Abstract
Autism spectrum disorders (ASD) are complex neurodevelopmental disorders with a very large number of risk loci detected in the genome. However, at best, each of them explains rare cases, the majority being idiopathic. Genomic data on ASD derive mostly from post-mortem brain analyses or cell lines derived from blood or patient-specific induced pluripotent stem cells (iPSCS). Therefore, the transcriptional and regulatory architecture of the nervous system, particularly during early developmental periods, remains highly incomplete. To access the critical disturbances that may have occurred during pregnancy or early childhood, we recently isolated stem cells from the nasal cavity of anesthetized patients diagnosed for ASD and compared them to stem cells from gender-matched control individuals without neuropsychiatric disorders. This allowed us to discover MOCOS, a non-mutated molybdenum cofactor sulfurase-coding gene that was under-expressed in the stem cells of most ASD patients of our cohort, disturbing redox homeostasis and synaptogenesis. We now report that a divergent transcription upstream of MOCOS generates an antisense long noncoding RNA, to which we coined the name COSMOC. Surprisingly, COSMOC is strongly under-expressed in all ASD patients of our cohort with the exception of a patient affected by Asperger syndrome. Knockdown studies indicate that loss of COSMOC reduces MOCOS expression, destabilizes lipid and energy metabolisms of stem cells, but also affects neuronal maturation and splicing of synaptic genes. Impaired expression of the COSMOC/MOCOS bidirectional unit might shed new lights on the origins of ASD that could be of importance for future translational studies.
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Affiliation(s)
- Pauline Rontani
- grid.5399.60000 0001 2176 4817Aix Marseille University, CNRS, INP, UMR 7051 Marseille, France
| | - Olivier Perche
- grid.112485.b0000 0001 0217 6921Orléans University, CNRS, INEM, UMR 7355 Orleans, France ,Department of Genetics, Regional Hospital, Orleans, France
| | - Louise Greetham
- grid.5399.60000 0001 2176 4817Aix Marseille University, CNRS, INP, UMR 7051 Marseille, France
| | - Nicolas Jullien
- grid.5399.60000 0001 2176 4817Aix Marseille University, CNRS, INP, UMR 7051 Marseille, France
| | - Bruno Gepner
- grid.5399.60000 0001 2176 4817Aix Marseille University, CNRS, INP, UMR 7051 Marseille, France
| | - François Féron
- grid.5399.60000 0001 2176 4817Aix Marseille University, CNRS, INP, UMR 7051 Marseille, France
| | - Emmanuel Nivet
- grid.5399.60000 0001 2176 4817Aix Marseille University, CNRS, INP, UMR 7051 Marseille, France
| | - Madeleine Erard-Garcia
- Aix Marseille University, CNRS, INP, UMR 7051, Marseille, France. .,Orléans University, CNRS, INEM, UMR 7355, Orleans, France.
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39
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Szeto RA, Tran T, Truong J, Negraes PD, Trujillo CA. RNA processing in neurological tissue: development, aging and disease. Semin Cell Dev Biol 2020; 114:57-67. [PMID: 33077405 DOI: 10.1016/j.semcdb.2020.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 07/29/2020] [Accepted: 09/07/2020] [Indexed: 12/13/2022]
Abstract
Gene expression comprises a diverse array of enzymes, proteins, non-coding transcripts, and cellular structures to guide the transfer of genetic information to its various final products. In the brain, the coordination among genes, or lack thereof, characterizes individual brain regions, mediates a variety of brain-related disorders, and brings light to fundamental differences between species. RNA processing, occurring between transcription and translation, controls an essential portion of gene expression through splicing, editing, localization, stability, and interference. The machinery to regulate transcripts must operate with precision serving as a blueprint for proteins and non-coding RNAs to derive their identity. Therefore, RNA processing has a broad scope of influence in the brain, as it modulates cell morphogenesis during development and underlies mechanisms behind certain neurological diseases. Here, we present these ideas through recent findings on RNA processing in development and post-developmental maturity to advance therapeutic discoveries and the collective knowledge of the RNA life cycle.
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Affiliation(s)
- Ryan A Szeto
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Timothy Tran
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Justin Truong
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Priscilla D Negraes
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Cleber A Trujillo
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA 92037, USA.
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40
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Oku S, Feng H, Connor S, Toledo A, Zhang P, Zhang Y, Thoumine O, Zhang C, Craig AM. Alternative splicing at neuroligin site A regulates glycan interaction and synaptogenic activity. eLife 2020; 9:58668. [PMID: 32915137 PMCID: PMC7486126 DOI: 10.7554/elife.58668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/31/2020] [Indexed: 01/18/2023] Open
Abstract
Post-transcriptional mechanisms regulating cell surface synaptic organizing complexes that control the properties of connections in brain circuits are poorly understood. Alternative splicing regulates the prototypical synaptic organizing complex, neuroligin-neurexin. In contrast to the well-studied neuroligin splice site B, little is known about splice site A. We discovered that inclusion of the positively charged A1 insert in mouse neuroligin-1 increases its binding to heparan sulphate, a modification on neurexin. The A1 insert increases neurexin recruitment, presynaptic differentiation, and synaptic transmission mediated by neuroligin-1. We propose that the A1 insert could be a target for alleviating the consequences of deleterious NLGN1/3 mutations, supported by assays with the autism-linked neuroligin-1-P89L mutant. An enrichment of neuroligin-1 A1 in GABAergic neuron types suggests a role in synchrony of cortical circuits. Altogether, these data reveal an unusual mode by which neuroligin splicing controls synapse development through protein-glycan interaction and identify it as a potential therapeutic target.
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Affiliation(s)
- Shinichiro Oku
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Huijuan Feng
- Departments of Systems Biology and Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, United States
| | - Steven Connor
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada.,Department of Biology, York University, Toronto, Canada
| | - Andrea Toledo
- Interdisciplinary Institute for Neuroscience UMR 5297, CNRS and University of Bordeaux, Bordeaux, France
| | - Peng Zhang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Yue Zhang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Olivier Thoumine
- Interdisciplinary Institute for Neuroscience UMR 5297, CNRS and University of Bordeaux, Bordeaux, France
| | - Chaolin Zhang
- Departments of Systems Biology and Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, United States
| | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
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41
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Hu Q, Greene CS, Heller EA. Specific histone modifications associate with alternative exon selection during mammalian development. Nucleic Acids Res 2020; 48:4709-4724. [PMID: 32319526 PMCID: PMC7229819 DOI: 10.1093/nar/gkaa248] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/23/2020] [Accepted: 04/02/2020] [Indexed: 12/29/2022] Open
Abstract
Alternative splicing (AS) is frequent during early mouse embryonic development. Specific histone post-translational modifications (hPTMs) have been shown to regulate exon splicing by either directly recruiting splice machinery or indirectly modulating transcriptional elongation. In this study, we hypothesized that hPTMs regulate expression of alternatively spliced genes for specific processes during differentiation. To address this notion, we applied an innovative machine learning approach to relate global hPTM enrichment to AS regulation during mammalian tissue development. We found that specific hPTMs, H3K36me3 and H3K4me1, play a role in skipped exon selection among all the tissues and developmental time points examined. In addition, we used iterative random forest model and found that interactions of multiple hPTMs most strongly predicted splicing when they included H3K36me3 and H3K4me1. Collectively, our data demonstrated a link between hPTMs and alternative splicing which will drive further experimental studies on the functional relevance of these modifications to alternative splicing.
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Affiliation(s)
- Qiwen Hu
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Casey S Greene
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Elizabeth A Heller
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
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42
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Qian H, Kang X, Hu J, Zhang D, Liang Z, Meng F, Zhang X, Xue Y, Maimon R, Dowdy SF, Devaraj NK, Zhou Z, Mobley WC, Cleveland DW, Fu XD. Reversing a model of Parkinson's disease with in situ converted nigral neurons. Nature 2020; 582:550-556. [PMID: 32581380 PMCID: PMC7521455 DOI: 10.1038/s41586-020-2388-4] [Citation(s) in RCA: 284] [Impact Index Per Article: 71.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 05/13/2020] [Indexed: 12/21/2022]
Abstract
Parkinson's disease is characterized by loss of dopamine neurons in the substantia nigra1. Similar to other major neurodegenerative disorders, there are no disease-modifying treatments for Parkinson's disease. While most treatment strategies aim to prevent neuronal loss or protect vulnerable neuronal circuits, a potential alternative is to replace lost neurons to reconstruct disrupted circuits2. Here we report an efficient one-step conversion of isolated mouse and human astrocytes to functional neurons by depleting the RNA-binding protein PTB (also known as PTBP1). Applying this approach to the mouse brain, we demonstrate progressive conversion of astrocytes to new neurons that innervate into and repopulate endogenous neural circuits. Astrocytes from different brain regions are converted to different neuronal subtypes. Using a chemically induced model of Parkinson's disease in mouse, we show conversion of midbrain astrocytes to dopaminergic neurons, which provide axons to reconstruct the nigrostriatal circuit. Notably, re-innervation of striatum is accompanied by restoration of dopamine levels and rescue of motor deficits. A similar reversal of disease phenotype is also accomplished by converting astrocytes to neurons using antisense oligonucleotides to transiently suppress PTB. These findings identify a potentially powerful and clinically feasible approach to treating neurodegeneration by replacing lost neurons.
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Affiliation(s)
- Hao Qian
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Xinjiang Kang
- State Key Laboratory of Membrane Biology and Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China.,MOE Key Lab of Medical Electrophysiology, ICR, Southwest Medical University, Luzhou, China
| | - Jing Hu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Dongyang Zhang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Zhengyu Liang
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Fan Meng
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Xuan Zhang
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Yuanchao Xue
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Roy Maimon
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA, USA
| | - Steven F Dowdy
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Neal K Devaraj
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Zhuan Zhou
- State Key Laboratory of Membrane Biology and Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - William C Mobley
- Department of Neurosciences and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA
| | - Don W Cleveland
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.,Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA, USA
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA. .,Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA, USA.
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43
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Fochi S, Lorenzi P, Galasso M, Stefani C, Trabetti E, Zipeto D, Romanelli MG. The Emerging Role of the RBM20 and PTBP1 Ribonucleoproteins in Heart Development and Cardiovascular Diseases. Genes (Basel) 2020; 11:genes11040402. [PMID: 32276354 PMCID: PMC7230170 DOI: 10.3390/genes11040402] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 12/17/2022] Open
Abstract
Alternative splicing is a regulatory mechanism essential for cell differentiation and tissue organization. More than 90% of human genes are regulated by alternative splicing events, which participate in cell fate determination. The general mechanisms of splicing events are well known, whereas only recently have deep-sequencing, high throughput analyses and animal models provided novel information on the network of functionally coordinated, tissue-specific, alternatively spliced exons. Heart development and cardiac tissue differentiation require thoroughly regulated splicing events. The ribonucleoprotein RBM20 is a key regulator of the alternative splicing events required for functional and structural heart properties, such as the expression of TTN isoforms. Recently, the polypyrimidine tract-binding protein PTBP1 has been demonstrated to participate with RBM20 in regulating splicing events. In this review, we summarize the updated knowledge relative to RBM20 and PTBP1 structure and molecular function; their role in alternative splicing mechanisms involved in the heart development and function; RBM20 mutations associated with idiopathic dilated cardiovascular disease (DCM); and the consequences of RBM20-altered expression or dysfunction. Furthermore, we discuss the possible application of targeting RBM20 in new approaches in heart therapies.
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44
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Monzón-Casanova E, Matheson LS, Tabbada K, Zarnack K, Smith CWJ, Turner M. Polypyrimidine tract-binding proteins are essential for B cell development. eLife 2020; 9:e53557. [PMID: 32081131 PMCID: PMC7058386 DOI: 10.7554/elife.53557] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/20/2020] [Indexed: 12/17/2022] Open
Abstract
Polypyrimidine tract-binding protein 1 (PTBP1) is a RNA-binding protein (RBP) expressed throughout B cell development. Deletion of Ptbp1 in mouse pro-B cells results in upregulation of PTBP2 and normal B cell development. We show that PTBP2 compensates for PTBP1 in B cell ontogeny as deletion of both Ptbp1 and Ptbp2 results in a complete block at the pro-B cell stage and a lack of mature B cells. In pro-B cells PTBP1 ensures precise synchronisation of the activity of cyclin dependent kinases at distinct stages of the cell cycle, suppresses S-phase entry and promotes progression into mitosis. PTBP1 controls mRNA abundance and alternative splicing of important cell cycle regulators including CYCLIN-D2, c-MYC, p107 and CDC25B. Our results reveal a previously unrecognised mechanism mediated by a RBP that is essential for B cell ontogeny and integrates transcriptional and post-translational determinants of progression through the cell cycle.
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Affiliation(s)
- Elisa Monzón-Casanova
- Laboratory of Lymphocyte Signalling and Development, The Babraham InstituteCambridgeUnited Kingdom
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Louise S Matheson
- Laboratory of Lymphocyte Signalling and Development, The Babraham InstituteCambridgeUnited Kingdom
| | - Kristina Tabbada
- Next Generation Sequencing Facility, The Babraham InstituteCambridgeUnited Kingdom
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences, Goethe University FrankfurtFrankfurt am MainGermany
| | | | - Martin Turner
- Laboratory of Lymphocyte Signalling and Development, The Babraham InstituteCambridgeUnited Kingdom
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45
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Hong W, Zhang W, Guan R, Liang Y, Hu S, Ji Y, Liu M, Lu H, Yu M, Ma L. Genome-wide profiling of prognosis-related alternative splicing signatures in sarcoma. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:557. [PMID: 31807538 PMCID: PMC6861818 DOI: 10.21037/atm.2019.09.65] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 09/06/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND Sarcomas (SARCs) are rare malignant tumors with poor prognosis. Increasing evidence has suggested that aberrant alternative splicing (AS) is strongly associated with tumor initiation and progression. We considered whether survival-related AS events might serve as prognosis predictors and underlying targeted molecules in SARC treatment. METHODS RNA-Seq data of the SARC cohort were downloaded from The Cancer Genome Atlas (TCGA) database. Survival-related AS events were selected by univariate and multivariate Cox regression analyses. Metascape was used for constructing a gene interaction network and performing functional enrichment analysis. Then, prognosis predictors were established based on statistically significant survival-related AS events and evaluated by receiver operator characteristic (ROC) curve analysis. Finally, the potential regulatory network was analyzed via Pearson's correlation between survival-related AS events and splicing factors (SFs). RESULTS A total of 3,610 AS events and 2,291 genes were found to be prognosis-related in 261 SARC samples. The focal adhesion pathway was identified as the most critical molecular mechanism corresponding to poor prognosis. Notably, several prognosis predictors based on survival-related AS events showed excellent performance in prognosis prediction. The area under the curve of the ROC of the risk score was 0.85 in the integrated predictor. The splicing network proved complicated regulation between prognosis-related SFs and AS events. Also, driver gene mutations were significantly associated with AS in SARC patients. CONCLUSIONS Survival-related AS events may become ideal indictors for the prognosis prediction of SARCs. Corresponding splicing regulatory mechanisms are worth further exploration.
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Affiliation(s)
- Weifeng Hong
- Department of Medical Imaging, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, China
| | - Weicong Zhang
- Department of Orthopaedics, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai 519000, China
| | - Renguo Guan
- Department of General Surgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510000, China
| | - Yuying Liang
- Department of Medical Imaging, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, China
| | - Shixiong Hu
- Department of General Surgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510000, China
| | - Yayun Ji
- Department of Medical Imaging, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, China
| | - Mouyuan Liu
- Department of Medical Imaging, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, China
| | - Hai Lu
- Department of Orthopaedics, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai 519000, China
| | - Min Yu
- Department of General Surgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510000, China
| | - Liheng Ma
- Department of Medical Imaging, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, China
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Translating neural stem cells to neurons in the mammalian brain. Cell Death Differ 2019; 26:2495-2512. [PMID: 31551564 DOI: 10.1038/s41418-019-0411-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 07/05/2019] [Accepted: 08/08/2019] [Indexed: 02/07/2023] Open
Abstract
The mammalian neocortex underlies our perception of sensory information, performance of motor activities, and higher-order cognition. During mammalian embryogenesis, radial glial precursor cells sequentially give rise to diverse populations of excitatory cortical neurons, followed by astrocytes and oligodendrocytes. A subpopulation of these embryonic neural precursors persists into adulthood as neural stem cells, which give rise to inhibitory interneurons and glia. Although the intrinsic mechanisms instructing the genesis of these distinct progeny have been well-studied, most work to date has focused on transcriptional, epigenetic, and cell-cycle control. Recent studies, however, have shown that posttranscriptional mechanisms also regulate the cell fate choices of transcriptionally primed neural precursors during cortical development. These mechanisms are mediated primarily by RNA-binding proteins and microRNAs that coordinately regulate mRNA translation, stability, splicing, and localization. Together, these findings point to an extensive network of posttranscriptional control and provide insight into both normal cortical development and disease. They also add another layer of complexity to brain development and raise important biological questions for future investigation.
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47
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Lian S, Li L, Zhou Y, Liu Z, Wang L. The co-expression networks of differentially expressed RBPs with TFs and LncRNAs related to clinical TNM stages of cancers. PeerJ 2019; 7:e7696. [PMID: 31576243 PMCID: PMC6753928 DOI: 10.7717/peerj.7696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/19/2019] [Indexed: 12/17/2022] Open
Abstract
Background RNA-binding proteins (RBPs) play important roles in cellular homeostasis by regulating the expression of thousands of transcripts, which have been reported to be involved in human tumorigenesis. Despite previous reports of the dysregulation of RBPs in cancers, the degree of dysregulation of RBPs in cancers and the intrinsic relevance between dysregulated RBPs and clinical TNM information remains unknown. Furthermore, the co-expressed networks of dysregulated RBPs with transcriptional factors and lncRNAs also require further investigation. Results Here, we firstly analyzed the deviations of expression levels of 1,542 RBPs from 20 cancer types and found that (1) RBPs are dysregulated in almost all 20 cancer types, especially in BLCA, COAD, READ, STAD, LUAD, LUSC and GBM with proportion of deviation larger than 300% compared with non-RBPs in normal tissues. (2) Up- and down-regulated RBPs also show opposed patterns of differential expression in cancers and normal tissues. In addition, down-regulated RBPs show a greater degree of dysregulated expression than up-regulated RBPs do. Secondly, we analyzed the intrinsic relevance between dysregulated RBPs and clinical TNM information and found that (3) Clinical TNM information for two cancer types—CHOL and KICH—is shown to be closely related to patterns of differentially expressed RBPs (DE RBPs) by co-expression cluster analysis. Thirdly, we identified ten key RBPs (seven down-regulated and three up-regulated) in CHOL and seven key RBPs (five down-regulated and two up-regulated) in KICH by analyzing co-expression correlation networks. Fourthly, we constructed the co-expression networks of key RBPs between 1,570 TFs and 4,147 lncRNAs for CHOL and KICH, respectively. Conclusions These results may provide an insight into the understanding of the functions of RBPs in human carcinogenesis. Furthermore, key RBPs and the co-expressed networks offer useful information for potential prognostic biomarkers and therapeutic targets for patients with cancers at the N and M stages in two cancer types CHOL and KICH.
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Affiliation(s)
- Shuaibin Lian
- College of Physics and Electronic Engineering, XinYang Normal University, Xinyang, HeNan, China
| | - Liansheng Li
- College of Life Sciences, XinYang Normal University, Xinyang, HeNan, China
| | - Yongjie Zhou
- College of Physics and Electronic Engineering, XinYang Normal University, Xinyang, HeNan, China
| | - Zixiao Liu
- College of Physics and Electronic Engineering, XinYang Normal University, Xinyang, HeNan, China
| | - Lei Wang
- College of Life Sciences, XinYang Normal University, Xinyang, HeNan, China
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More than a messenger: Alternative splicing as a therapeutic target. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194395. [PMID: 31271898 DOI: 10.1016/j.bbagrm.2019.06.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 12/30/2022]
Abstract
Alternative splicing of pre-mRNA is an essential post- and co-transcriptional mechanism of gene expression regulation that produces multiple mature mRNA transcripts from a single gene. Genetic mutations that affect splicing underlie numerous devastating diseases. The complexity of splicing regulation allows for multiple therapeutic approaches to correct disease-associated mis-splicing events. In this review, we first highlight recent findings from therapeutic strategies that have used splice switching antisense oligonucleotides and small molecules that bind directly to RNA. Second, we summarize different genetic and chemical approaches to target components of the spliceosome to correct splicing defects in pathological conditions. Finally, we present an overview of compounds that target kinases and accessory pathways that intersect with the splicing machinery. Advancements in the understanding of disease-specific defects caused by mis-regulation of alternative splicing will certainly increase the development of therapeutic options for the clinic. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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An RNA Switch of a Large Exon of Ninein Is Regulated by the Neural Stem Cell Specific-RNA Binding Protein, Qki5. Int J Mol Sci 2019; 20:ijms20051010. [PMID: 30813567 PMCID: PMC6429586 DOI: 10.3390/ijms20051010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 12/20/2022] Open
Abstract
A set of tissue-specific splicing factors are thought to govern alternative splicing events during neural progenitor cell (NPC)-to-neuron transition by regulating neuron-specific exons. Here, we propose one such factor, RNA-binding protein Quaking 5 (Qki5), which is specifically expressed in the early embryonic neural stem cells. We performed mRNA-SEQ (Sequence) analysis using mRNAs obtained by developing cerebral cortices in Qk (Quaking) conditional knockout (cKO) mice. As expected, we found a large number of alternative splicing changes between control and conditional knockouts relative to changes in transcript levels. DAVID (The Database for Annotation, Visualization and Integrated Discovery) and Metascape analyses suggested that the affected spliced genes are involved in axon development and microtubule-based processes. Among these, the mRNA coding for the Ninein protein is listed as one of Qki protein-dependent alternative splicing targets. Interestingly, this exon encodes a very long polypeptide (2121 nt), and has been previously defined as a dynamic RNA switch during the NPC-to-neuron transition. Additionally, we validated that the regulation of this large exon is consistent with the Qki5-dependent alternative exon inclusion mode suggested by our previous Qki5 HITS-CLIP (high throughput sequencing-cross linking immunoprecipitation) analysis. Taken together, these data suggest that Qki5 is an important factor for alternative splicing in the NPC-to-neuron transition.
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Zhang M, Ergin V, Lin L, Stork C, Chen L, Zheng S. Axonogenesis Is Coordinated by Neuron-Specific Alternative Splicing Programming and Splicing Regulator PTBP2. Neuron 2019; 101:690-706.e10. [PMID: 30733148 DOI: 10.1016/j.neuron.2019.01.022] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 11/08/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022]
Abstract
How a neuron acquires an axon is a fundamental question. Piecemeal identification of many axonogenesis-related genes has been done, but coordinated regulation is unknown. Through unbiased transcriptome profiling of immature primary cortical neurons during early axon formation, we discovered an association between axonogenesis and neuron-specific alternative splicing. Known axonogenesis genes exhibit little expression alternation but widespread splicing changes. Axonogenesis-associated splicing is governed by RNA binding protein PTBP2, which is enriched in neurons and peaks around axonogenesis in the brain. Cortical depletion of PTBP2 prematurely induces axonogenesis-associated splicing, causes imbalanced expression of axonogenesis-associated isoforms, and specifically affects axon formation in vitro and in vivo. PTBP2-controlled axonogenesis-associated Shtn1 splicing determines SHTN1's capacity to regulate actin interaction, polymerization, and axon growth. Precocious Shtn1 isoform switch contributes to disorganized axon formation of Ptbp2-/- neurons. We conclude that PTBP2-orchestrated alternative splicing programming is required for robust generation of a single axon in mammals.
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Affiliation(s)
- Min Zhang
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Volkan Ergin
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Lin Lin
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Cheryl Stork
- Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Liang Chen
- Department of Biological Sciences, Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.
| | - Sika Zheng
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA; Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, Riverside, CA 92521, USA.
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