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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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Ritter AJ, Wallace A, Ronaghi N, Sanford J. junctionCounts: comprehensive alternative splicing analysis and prediction of isoform-level impacts to the coding sequence. NAR Genom Bioinform 2024; 6:lqae093. [PMID: 39131822 PMCID: PMC11310779 DOI: 10.1093/nargab/lqae093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 07/15/2024] [Accepted: 07/22/2024] [Indexed: 08/13/2024] Open
Abstract
Alternative splicing (AS) is emerging as an important regulatory process for complex biological processes. Transcriptomic studies therefore commonly involve the identification and quantification of alternative processing events, but the need for predicting the functional consequences of changes to the relative inclusion of alternative events remains largely unaddressed. Many tools exist for the former task, albeit each constrained to its own event type definitions. Few tools exist for the latter task; each with significant limitations. To address these issues we developed junctionCounts, which captures both simple and complex pairwise AS events and quantifies them with straightforward exon-exon and exon-intron junction reads in RNA-seq data, performing competitively among similar tools in terms of sensitivity, false discovery rate and quantification accuracy. Its partner utility, cdsInsertion, identifies transcript coding sequence (CDS) information via in silico translation from annotated start codons, including the presence of premature termination codons. Finally, findSwitchEvents connects AS events with CDS information to predict the impact of individual events to the isoform-level CDS. We used junctionCounts to characterize splicing dynamics and NMD regulation during neuronal differentiation across four primates, demonstrating junctionCounts' capacity to robustly characterize AS in a variety of organisms and to predict its effect on mRNA isoform fate.
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Affiliation(s)
- Alexander J Ritter
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andrew Wallace
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Neda Ronaghi
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Jeremy R Sanford
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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3
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Yustis JC, Devoucoux M, Côté J. The Functional Relationship Between RNA Splicing and the Chromatin Landscape. J Mol Biol 2024; 436:168614. [PMID: 38762032 DOI: 10.1016/j.jmb.2024.168614] [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: 03/04/2024] [Revised: 04/27/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Chromatin is a highly regulated and dynamic structure that has been shown to play an essential role in transcriptional and co-transcriptional regulation. In the context of RNA splicing, early evidence suggested a loose connection between the chromatin landscape and splicing. More recently, it has been shown that splicing occurs in a co-transcriptional manner, meaning that the splicing process occurs in the context of chromatin. Experimental and computational evidence have also shown that chromatin dynamics can influence the splicing process and vice versa. However, much of this evidence provides mainly correlative relationships between chromatin and splicing with just a few concrete examples providing defined molecular mechanisms by which these two processes are functionally related. Nevertheless, it is clear that chromatin and RNA splicing are tightly interconnected to one another. In this review, we highlight the current state of knowledge of the relationship between chromatin and splicing.
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Affiliation(s)
- Juan-Carlos Yustis
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Oncology Division of the CHU de Québec-Université Laval Research Center, Quebec City, Quebec G1R 3S3, Canada
| | - Maëva Devoucoux
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Oncology Division of the CHU de Québec-Université Laval Research Center, Quebec City, Quebec G1R 3S3, Canada
| | - Jacques Côté
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Oncology Division of the CHU de Québec-Université Laval Research Center, Quebec City, Quebec G1R 3S3, Canada.
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4
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Martin RA, Viggars MR, Sanford JA, Taylor ZW, Hansen JR, Clair GC, Adkins JN, Douglas CM, Esser KA. Alterations of the skeletal muscle nuclear proteome after acute exercise reveals a post-transcriptional influence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.08.607176. [PMID: 39149399 PMCID: PMC11326304 DOI: 10.1101/2024.08.08.607176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Exercise is firmly established as a key contributor to overall well-being and is frequently employed as a therapeutic approach to mitigate various health conditions. One pivotal aspect of the impact of exercise lies in the systemic transcriptional response, which underpins its beneficial adaptations. While extensive research has been devoted to understanding the transcriptional response to exercise, our knowledge of the protein constituents of nuclear processes that accompany gene expression in skeletal muscle remains largely elusive. We hypothesize that alterations in the nuclear proteome following exercise hold vital clues for comprehending the transcriptional regulation and other related nuclear functions. We isolated skeletal muscle nuclei from C57BL/6 mice both sedentary control and one-hour post 30-minute treadmill running, to gain insights into the nuclear proteome after exercise. A substantial number of the 2,323 proteins identified, were related to nuclear functions. For instance, we found 59 proteins linked to nucleocytoplasmic transport were higher in sedentary mice compared to exercise, hinting at an exercise-induced modulation to nuclear trafficking. Furthermore, 135 proteins exhibited increased abundance after exercise (FDR < 0.1) while 89 proteins decreased, with the most prominent changes in proteins linked to mRNA processing and splicing. Super resolution microscopy further highlights potential localization change in mRNA processing proteins post-exercise, further suggesting changes in nuclear transport dynamics. Nonetheless, our data provide important considerations for the study of the nuclear proteome and supports a paradigm through which exercise downregulated mRNA processing and splicing, offering valuable insights into the broader landscape of the impact from acute exercise. New & Noteworthy Exercise plays a crucial role in promoting muscle health, but our understanding of nuclear proteins orchestrating exercise responses is limited. Isolation of skeletal muscle nuclei coupled with mass spectrometry enhanced the identification of nuclear proteins. This approach was used to investigate the effects of acute exercise, revealing changes in the muscle nuclear proteome 1-hour post-exercise, including proteins linked to post-transcriptional processing and splicing. Our findings offer insights into the exercise-induced changes within muscle nuclear proteins.
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Affiliation(s)
- Ryan A. Martin
- Department of Physiology and Aging, University of Florida, Gainesville, FL, USA
- Myology Institute, University of Florida, Gainesville, FL, USA
| | - Mark R. Viggars
- Department of Physiology and Aging, University of Florida, Gainesville, FL, USA
- Myology Institute, University of Florida, Gainesville, FL, USA
| | | | - Zane W. Taylor
- Pacific Northwest National Laboratory, Richland, WA, USA
| | | | | | - Joshua N. Adkins
- Pacific Northwest National Laboratory, Richland, WA, USA
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA
| | - Collin M. Douglas
- Department of Physiology and Aging, University of Florida, Gainesville, FL, USA
- Myology Institute, University of Florida, Gainesville, FL, USA
| | - Karyn A. Esser
- Department of Physiology and Aging, University of Florida, Gainesville, FL, USA
- Myology Institute, University of Florida, Gainesville, FL, USA
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Tilliole P, Fix S, Godin JD. hnRNPs: roles in neurodevelopment and implication for brain disorders. Front Mol Neurosci 2024; 17:1411639. [PMID: 39086926 PMCID: PMC11288931 DOI: 10.3389/fnmol.2024.1411639] [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: 04/03/2024] [Accepted: 06/17/2024] [Indexed: 08/02/2024] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) constitute a family of multifunctional RNA-binding proteins able to process nuclear pre-mRNAs into mature mRNAs and regulate gene expression in multiple ways. They comprise at least 20 different members in mammals, named from A (HNRNP A1) to U (HNRNP U). Many of these proteins are components of the spliceosome complex and can modulate alternative splicing in a tissue-specific manner. Notably, while genes encoding hnRNPs exhibit ubiquitous expression, increasing evidence associate these proteins to various neurodevelopmental and neurodegenerative disorders, such as intellectual disability, epilepsy, microcephaly, amyotrophic lateral sclerosis, or dementias, highlighting their crucial role in the central nervous system. This review explores the evolution of the hnRNPs family, highlighting the emergence of numerous new members within this family, and sheds light on their implications for brain development.
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Affiliation(s)
- Pierre Tilliole
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, IGBMC, Illkirch, France
- Centre National de la Recherche Scientifique, CNRS, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, INSERM, U1258, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Simon Fix
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, IGBMC, Illkirch, France
- Centre National de la Recherche Scientifique, CNRS, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, INSERM, U1258, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Juliette D. Godin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, IGBMC, Illkirch, France
- Centre National de la Recherche Scientifique, CNRS, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, INSERM, U1258, Illkirch, France
- Université de Strasbourg, Strasbourg, France
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Li JD, Taipale M, Blencowe BJ. Efficient, specific, and combinatorial control of endogenous exon splicing with dCasRx-RBM25. Mol Cell 2024; 84:2573-2589.e5. [PMID: 38917795 DOI: 10.1016/j.molcel.2024.05.028] [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: 09/15/2023] [Revised: 04/24/2024] [Accepted: 05/30/2024] [Indexed: 06/27/2024]
Abstract
Efficient targeted control of splicing is a major goal of functional genomics and therapeutic applications. Guide (g)RNA-directed, deactivated (d)Cas CRISPR enzymes fused to splicing effectors represent a promising strategy due to the flexibility of these systems. However, efficient, specific, and generalizable activation of endogenous exons using this approach has not been previously reported. By screening over 300 dCasRx-splicing factor fusion proteins tethered to splicing reporters, we identify dCasRx-RBM25 as a potent activator of exons. Moreover, dCasRx-RBM25 efficiently activates the splicing of ∼90% of targeted endogenous alternative exons and displays high on-target specificity. Using gRNA arrays for combinatorial targeting, we demonstrate that dCasRx-RBM25 enables multiplexed activation and repression of exons. Using this feature, the targeting of neural-regulated exons in Ptpb1 and Puf60 in embryonic stem cells reveals combinatorial effects on downstream alternative splicing events controlled by these factors. Collectively, our results enable versatile, combinatorial exon-resolution functional assays and splicing-directed therapeutic applications.
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Affiliation(s)
- Jack Daiyang Li
- Donnelly Centre, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Mikko Taipale
- Donnelly Centre, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
| | - Benjamin J Blencowe
- Donnelly Centre, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
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Zorn P, Calvo Sánchez J, Alakhras T, Schreier B, Gekle M, Hüttelmaier S, Köhn M. Rbfox1 controls alternative splicing of focal adhesion genes in cardiac muscle cells. J Mol Cell Biol 2024; 16:mjae003. [PMID: 38253401 PMCID: PMC11216089 DOI: 10.1093/jmcb/mjae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 11/30/2023] [Accepted: 01/19/2024] [Indexed: 01/24/2024] Open
Abstract
Alternative splicing is one of the major cellular processes that determine the tissue-specific expression of protein variants. However, it remains challenging to identify physiologically relevant and tissue-selective proteins that are generated by alternative splicing. Hence, we investigated the target spectrum of the splicing factor Rbfox1 in the cardiac muscle context in more detail. By using a combination of in silico target prediction and in-cell validation, we identified several focal adhesion proteins as alternative splicing targets of Rbfox1. We focused on the alternative splicing patterns of vinculin (metavinculin isoform) and paxillin (extended paxillin isoform) and identified both as potential Rbfox1 targets. Minigene analyses suggested that both isoforms are promoted by Rbfox1 due to binding in the introns. Focal adhesions play an important role in the cardiac muscle context, since they mainly influence cell shape, cytoskeletal organization, and cell-matrix association. Our data confirmed that depletion of Rbfox1 changed cardiomyoblast morphology, cytoskeletal organization, and multinuclearity after differentiation, which might be due to changes in alternative splicing of focal adhesion proteins. Hence, our results indicate that Rbfox1 promotes alternative splicing of focal adhesion genes in cardiac muscle cells, which might contribute to heart disease progression, where downregulation of Rbfox1 is frequently observed.
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Affiliation(s)
- Peter Zorn
- Junior Group ‘Non-coding RNAs and RBPs in Human Diseases’, Medical Faculty, University of Halle–Wittenberg, 06120 Halle (Saale), Germany
| | - Jaime Calvo Sánchez
- Junior Group ‘Non-coding RNAs and RBPs in Human Diseases’, Medical Faculty, University of Halle–Wittenberg, 06120 Halle (Saale), Germany
| | - Tala Alakhras
- Junior Group ‘Non-coding RNAs and RBPs in Human Diseases’, Medical Faculty, University of Halle–Wittenberg, 06120 Halle (Saale), Germany
| | - Barbara Schreier
- Julius Bernstein Institute of Physiology, Medical Faculty, University of Halle–Wittenberg, 06112 Halle (Saale), Germany
| | - Michael Gekle
- Julius Bernstein Institute of Physiology, Medical Faculty, University of Halle–Wittenberg, 06112 Halle (Saale), Germany
| | - Stefan Hüttelmaier
- Institute of Molecular Medicine, Medical Faculty, University of Halle–Wittenberg, 06120 Halle (Saale), Germany
| | - Marcel Köhn
- Junior Group ‘Non-coding RNAs and RBPs in Human Diseases’, Medical Faculty, University of Halle–Wittenberg, 06120 Halle (Saale), Germany
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8
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Liang S, Zhou J, Yu X, Lu S, Liu R. Neuronal conversion from glia to replenish the lost neurons. Neural Regen Res 2024; 19:1446-1453. [PMID: 38051886 PMCID: PMC10883502 DOI: 10.4103/1673-5374.386400] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 08/16/2023] [Indexed: 12/07/2023] Open
Abstract
ABSTRACT Neuronal injury, aging, and cerebrovascular and neurodegenerative diseases such as cerebral infarction, Alzheimer's disease, Parkinson's disease, frontotemporal dementia, amyotrophic lateral sclerosis, and Huntington's disease are characterized by significant neuronal loss. Unfortunately, the neurons of most mammals including humans do not possess the ability to self-regenerate. Replenishment of lost neurons becomes an appealing therapeutic strategy to reverse the disease phenotype. Transplantation of pluripotent neural stem cells can supplement the missing neurons in the brain, but it carries the risk of causing gene mutation, tumorigenesis, severe inflammation, and obstructive hydrocephalus induced by brain edema. Conversion of neural or non-neural lineage cells into functional neurons is a promising strategy for the diseases involving neuron loss, which may overcome the above-mentioned disadvantages of neural stem cell therapy. Thus far, many strategies to transform astrocytes, fibroblasts, microglia, Müller glia, NG2 cells, and other glial cells to mature and functional neurons, or for the conversion between neuronal subtypes have been developed through the regulation of transcription factors, polypyrimidine tract binding protein 1 (PTBP1), and small chemical molecules or are based on a combination of several factors and the location in the central nervous system. However, some recent papers did not obtain expected results, and discrepancies exist. Therefore, in this review, we discuss the history of neuronal transdifferentiation, summarize the strategies for neuronal replenishment and conversion from glia, especially astrocytes, and point out that biosafety, new strategies, and the accurate origin of the truly converted neurons in vivo should be focused upon in future studies. It also arises the attention of replenishing the lost neurons from glia by gene therapies such as up-regulation of some transcription factors or down-regulation of PTBP1 or drug interference therapies.
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Affiliation(s)
- Shiyu Liang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Jing Zhou
- Department of Geriatric Rehabilitation, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Xiaolin Yu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Shuai Lu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Ruitian Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
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9
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Zhuravskaya A, Yap K, Hamid F, Makeyev EV. Alternative splicing coupled to nonsense-mediated decay coordinates downregulation of non-neuronal genes in developing mouse neurons. Genome Biol 2024; 25:162. [PMID: 38902825 PMCID: PMC11188260 DOI: 10.1186/s13059-024-03305-8] [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: 07/08/2023] [Accepted: 06/07/2024] [Indexed: 06/22/2024] Open
Abstract
BACKGROUND The functional coupling between alternative pre-mRNA splicing (AS) and the mRNA quality control mechanism called nonsense-mediated decay (NMD) can modulate transcript abundance. Previous studies have identified several examples of such a regulation in developing neurons. However, the systems-level effects of AS-NMD in this context are poorly understood. RESULTS We developed an R package, factR2, which offers a comprehensive suite of AS-NMD analysis functions. Using this tool, we conducted a longitudinal analysis of gene expression in pluripotent stem cells undergoing induced neuronal differentiation. Our analysis uncovers hundreds of AS-NMD events with significant potential to regulate gene expression. Notably, this regulation is significantly overrepresented in specific functional groups of developmentally downregulated genes. Particularly strong association with gene downregulation is detected for alternative cassette exons stimulating NMD upon their inclusion into mature mRNA. By combining bioinformatic analyses with CRISPR/Cas9 genome editing and other experimental approaches we show that NMD-stimulating cassette exons regulated by the RNA-binding protein PTBP1 dampen the expression of their genes in developing neurons. We also provided evidence that the inclusion of NMD-stimulating cassette exons into mature mRNAs is temporally coordinated with NMD-independent gene repression mechanisms. CONCLUSIONS Our study provides an accessible workflow for the discovery and prioritization of AS-NMD targets. It further argues that the AS-NMD pathway plays a widespread role in developing neurons by facilitating the downregulation of functionally related non-neuronal genes.
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Affiliation(s)
- Anna Zhuravskaya
- Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
| | - Karen Yap
- Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
| | - Fursham Hamid
- Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK.
| | - Eugene V Makeyev
- Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK.
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10
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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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11
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Joglekar A, Hu W, Zhang B, Narykov O, Diekhans M, Marrocco J, Balacco J, Ndhlovu LC, Milner TA, Fedrigo O, Jarvis ED, Sheynkman G, Korkin D, Ross ME, Tilgner HU. Single-cell long-read sequencing-based mapping reveals specialized splicing patterns in developing and adult mouse and human brain. Nat Neurosci 2024; 27:1051-1063. [PMID: 38594596 PMCID: PMC11156538 DOI: 10.1038/s41593-024-01616-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 03/07/2024] [Indexed: 04/11/2024]
Abstract
RNA isoforms influence cell identity and function. However, a comprehensive brain isoform map was lacking. We analyze single-cell RNA isoforms across brain regions, cell subtypes, developmental time points and species. For 72% of genes, full-length isoform expression varies along one or more axes. Splicing, transcription start and polyadenylation sites vary strongly between cell types, influence protein architecture and associate with disease-linked variation. Additionally, neurotransmitter transport and synapse turnover genes harbor cell-type variability across anatomical regions. Regulation of cell-type-specific splicing is pronounced in the postnatal day 21-to-postnatal day 28 adolescent transition. Developmental isoform regulation is stronger than regional regulation for the same cell type. Cell-type-specific isoform regulation in mice is mostly maintained in the human hippocampus, allowing extrapolation to the human brain. Conversely, the human brain harbors additional cell-type specificity, suggesting gain-of-function isoforms. Together, this detailed single-cell atlas of full-length isoform regulation across development, anatomical regions and species reveals an unappreciated degree of isoform variability across multiple axes.
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Affiliation(s)
- Anoushka Joglekar
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
- New York Genome Center, New York, NY, USA
| | - Wen Hu
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Bei Zhang
- Spatial Genomics, Inc., Pasadena, CA, USA
| | - Oleksandr Narykov
- Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA
- Computer Science Department, Worcester Polytechnic Institute, Worcester, MA, USA
- Data Science Program, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Mark Diekhans
- UC Genomics Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Jordan Marrocco
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Department of Biology, Touro University, New York, NY, USA
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
| | - Jennifer Balacco
- Vertebrate Genome Lab, The Rockefeller University, New York, NY, USA
| | - Lishomwa C Ndhlovu
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Olivier Fedrigo
- Vertebrate Genome Lab, The Rockefeller University, New York, NY, USA
| | - Erich D Jarvis
- Vertebrate Genome Lab, The Rockefeller University, New York, NY, USA
- Laboratory of Neurogenetics of Language, The Rockefeller University, New York, NY, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Gloria Sheynkman
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
- UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, VA, USA
| | - Dmitry Korkin
- Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA
- Computer Science Department, Worcester Polytechnic Institute, Worcester, MA, USA
- Data Science Program, Worcester Polytechnic Institute, Worcester, MA, USA
| | - M Elizabeth Ross
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Hagen U Tilgner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA.
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12
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Cesari E, Farini D, Medici V, Ehrmann I, Guerra M, Testa E, Naro C, Geloso MC, Pagliarini V, La Barbera L, D’Amelio M, Orsini T, Vecchioli SF, Tamagnone L, Fort P, Viscomi MT, Elliott DJ, Sette C. Differential expression of paralog RNA binding proteins establishes a dynamic splicing program required for normal cerebral cortex development. Nucleic Acids Res 2024; 52:4167-4184. [PMID: 38324473 PMCID: PMC11077083 DOI: 10.1093/nar/gkae071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 01/17/2024] [Accepted: 01/25/2024] [Indexed: 02/09/2024] Open
Abstract
Sam68 and SLM2 are paralog RNA binding proteins (RBPs) expressed in the cerebral cortex and display similar splicing activities. However, their relative functions during cortical development are unknown. We found that these RBPs exhibit an opposite expression pattern during development. Sam68 expression declines postnatally while SLM2 increases after birth, and this developmental pattern is reinforced by hierarchical control of Sam68 expression by SLM2. Analysis of Sam68:Slm2 double knockout (Sam68:Slm2dko) mice revealed hundreds of exons that respond to joint depletion of these proteins. Moreover, parallel analysis of single and double knockout cortices indicated that exons regulated mainly by SLM2 are characterized by a dynamic splicing pattern during development, whereas Sam68-dependent exons are spliced at relatively constant rates. Dynamic splicing of SLM2-sensitive exons is completely suppressed in the Sam68:Slm2dko developing cortex. Sam68:Slm2dko mice die perinatally with defects in neurogenesis and in neuronal differentiation, and develop a hydrocephalus, consistent with splicing alterations in genes related to these biological processes. Thus, our study reveals that developmental control of separate Sam68 and Slm2 paralog genes encoding homologous RBPs enables the orchestration of a dynamic splicing program needed for brain development and viability, while ensuring a robust redundant mechanism that supports proper cortical development.
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Affiliation(s)
- Eleonora Cesari
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Donatella Farini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - Vanessa Medici
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Ingrid Ehrmann
- Newcastle University Centre for Cancer, Newcastle University Institute of Biosciences, Newcastle NE1 3BZ, UK
| | - Marika Guerra
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Erika Testa
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Maria Concetta Geloso
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Vittoria Pagliarini
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Livia La Barbera
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - Marcello D’Amelio
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
- Università Campus Bio-Medico di Roma, Via Álvaro del Portillo, 21, 00128 Rome, Italy
| | - Tiziana Orsini
- Institute of Biochemistry and Cell Biology, National Research Council (IBBC/CNR), Monterotondo, 00015 Rome, Italy
| | - Stefano Farioli Vecchioli
- Institute of Biochemistry and Cell Biology, National Research Council (IBBC/CNR), Monterotondo, 00015 Rome, Italy
| | - Luca Tamagnone
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - Philippe Fort
- Centre de Recherche en Biologie Cellulaire de Montpellier, University of Montpellier, CNRS, 1919 Route de Mende, 34293 Montpellier Cedex 05, France
| | - Maria Teresa Viscomi
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - David J Elliott
- Newcastle University Centre for Cancer, Newcastle University Institute of Biosciences, Newcastle NE1 3BZ, UK
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
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13
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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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14
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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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15
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Ciampi L, Serrano L, Irimia M. Unique transcriptomes of sensory and non-sensory neurons: insights from Splicing Regulatory States. Mol Syst Biol 2024; 20:296-310. [PMID: 38438733 PMCID: PMC10987577 DOI: 10.1038/s44320-024-00020-1] [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: 10/31/2023] [Revised: 01/04/2024] [Accepted: 01/12/2024] [Indexed: 03/06/2024] Open
Abstract
Alternative Splicing (AS) programs serve as instructive signals of cell type specificity, particularly within the brain, which comprises dozens of molecularly and functionally distinct cell types. Among them, retinal photoreceptors stand out due to their unique transcriptome, making them a particularly well-suited system for studying how AS shapes cell type-specific molecular functions. Here, we use the Splicing Regulatory State (SRS) as a novel framework to discuss the splicing factors governing the unique AS pattern of photoreceptors, and how this pattern may aid in the specification of their highly specialized sensory cilia. In addition, we discuss how other sensory cells with ciliated structures, for which data is much scarcer, also rely on specific SRSs to implement a proteome specialized in the detection of sensory stimuli. By reviewing the general rules of cell type- and tissue-specific AS programs, firstly in the brain and subsequently in specialized sensory neurons, we propose a novel paradigm on how SRSs are established and how they can diversify. Finally, we illustrate how SRSs shape the outcome of mutations in splicing factors to produce cell type-specific phenotypes that can lead to various human diseases.
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Affiliation(s)
- Ludovica Ciampi
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
| | - Luis Serrano
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
- Universitat Pompeu Fabra, Barcelona, Spain.
- ICREA, Barcelona, Spain.
| | - Manuel Irimia
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
- Universitat Pompeu Fabra, Barcelona, Spain.
- ICREA, Barcelona, Spain.
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16
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Engal E, Zhang Z, Geminder O, Jaffe-Herman S, Kay G, Ben-Hur A, Salton M. The spectrum of pre-mRNA splicing in autism. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1838. [PMID: 38509732 DOI: 10.1002/wrna.1838] [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: 09/29/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/22/2024]
Abstract
Disruptions in spatiotemporal gene expression can result in atypical brain function. Specifically, autism spectrum disorder (ASD) is characterized by abnormalities in pre-mRNA splicing. Abnormal splicing patterns have been identified in the brains of individuals with ASD, and mutations in splicing factors have been found to contribute to neurodevelopmental delays associated with ASD. Here we review studies that shed light on the importance of splicing observed in ASD and that explored the intricate relationship between splicing factors and ASD, revealing how disruptions in pre-mRNA splicing may underlie ASD pathogenesis. We provide an overview of the research regarding all splicing factors associated with ASD and place a special emphasis on five specific splicing factors-HNRNPH2, NOVA2, WBP4, SRRM2, and RBFOX1-known to impact the splicing of ASD-related genes. In the discussion of the molecular mechanisms influenced by these splicing factors, we lay the groundwork for a deeper understanding of ASD's complex etiology. Finally, we discuss the potential benefit of unraveling the connection between splicing and ASD for the development of more precise diagnostic tools and targeted therapeutic interventions. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution RNA Evolution and Genomics > Computational Analyses of RNA RNA-Based Catalysis > RNA Catalysis in Splicing and Translation.
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Affiliation(s)
- Eden Engal
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Zhenwei Zhang
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ophir Geminder
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shiri Jaffe-Herman
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gillian Kay
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Asa Ben-Hur
- Department of Computer Science, Colorado State University, Fort Collins, Colorado, USA
| | - Maayan Salton
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
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17
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Truong A, Barton M, Tran U, Mellody M, Berger D, Madory D, Hitch E, Jibrael B, Nikolaidis N, Luchko T, Keppetipola N. Unstructured linker regions play a role in the differential splicing activities of paralogous RNA binding proteins PTBP1 and PTBP2. J Biol Chem 2024; 300:105733. [PMID: 38336291 PMCID: PMC10914480 DOI: 10.1016/j.jbc.2024.105733] [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: 08/10/2023] [Revised: 01/23/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024] Open
Abstract
RNA Binding Proteins regulate, in part, alternative pre-mRNA splicing and, in turn, gene expression patterns. Polypyrimidine tract binding proteins PTBP1 and PTBP2 are paralogous RNA binding proteins sharing 74% amino acid sequence identity. Both proteins contain four structured RNA-recognition motifs (RRMs) connected by linker regions and an N-terminal region. Despite their similarities, the paralogs have distinct tissue-specific expression patterns and can regulate discrete sets of target exons. How two highly structurally similar proteins can exert different splicing outcomes is not well understood. Previous studies revealed that PTBP2 is post-translationally phosphorylated in the unstructured N-terminal, Linker 1, and Linker 2 regions that share less sequence identity with PTBP1 signifying a role for these regions in dictating the paralog's distinct splicing activities. To this end, we conducted bioinformatics analysis to determine the evolutionary conservation of RRMs versus linker regions in PTBP1 and PTBP2 across species. To determine the role of PTBP2 unstructured regions in splicing activity, we created hybrid PTBP1-PTBP2 constructs that had counterpart PTBP1 regions swapped to an otherwise PTBP2 protein and assayed on differentially regulated exons. We also conducted molecular dynamics studies to investigate how negative charges introduced by phosphorylation in PTBP2 unstructured regions can alter their physical properties. Collectively, results from our studies reveal an important role for PTBP2 unstructured regions and suggest a role for phosphorylation in the differential splicing activities of the paralogs on certain regulated exons.
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Affiliation(s)
- Anthony Truong
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, California, USA
| | - Michael Barton
- Department of Physics and Astronomy, California State University, Northridge, Northridge, California, USA
| | - Uyenphuong Tran
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, California, USA
| | - Montana Mellody
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, California, USA
| | - Devon Berger
- Department of Biological Sciences, California State University Fullerton, Fullerton, California, USA
| | - Dean Madory
- Department of Biological Science, Santa Ana College, Santa Ana, California, USA
| | - Elizabeth Hitch
- Department of Biological Sciences, California State University Fullerton, Fullerton, California, USA
| | - Basma Jibrael
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, California, USA
| | - Nikolas Nikolaidis
- Department of Biological Sciences, California State University Fullerton, Fullerton, California, USA
| | - Tyler Luchko
- Department of Physics and Astronomy, California State University, Northridge, Northridge, California, USA.
| | - Niroshika Keppetipola
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, California, USA.
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18
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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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19
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Lee S, Aubee JI, Lai EC. Regulation of alternative splicing and polyadenylation in neurons. Life Sci Alliance 2023; 6:e202302000. [PMID: 37793776 PMCID: PMC10551640 DOI: 10.26508/lsa.202302000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/06/2023] Open
Abstract
Cell-type-specific gene expression is a fundamental feature of multicellular organisms and is achieved by combinations of regulatory strategies. Although cell-restricted transcription is perhaps the most widely studied mechanism, co-transcriptional and post-transcriptional processes are also central to the spatiotemporal control of gene functions. One general category of expression control involves the generation of multiple transcript isoforms from an individual gene, whose balance and cell specificity are frequently tightly regulated via diverse strategies. The nervous system makes particularly extensive use of cell-specific isoforms, specializing the neural function of genes that are expressed more broadly. Here, we review regulatory strategies and RNA-binding proteins that direct neural-specific isoform processing. These include various classes of alternative splicing and alternative polyadenylation events, both of which broadly diversify the neural transcriptome. Importantly, global alterations of splicing and alternative polyadenylation are characteristic of many neural pathologies, and recent genetic studies demonstrate how misregulation of individual neural isoforms can directly cause mutant phenotypes.
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Affiliation(s)
- Seungjae Lee
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Joseph I Aubee
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
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20
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Liu HL, Lu XM, Wang HY, Hu KB, Wu QY, Liao P, Li S, Long ZY, Wang YT. The role of RNA splicing factor PTBP1 in neuronal development. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119506. [PMID: 37263298 DOI: 10.1016/j.bbamcr.2023.119506] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 05/23/2023] [Accepted: 05/26/2023] [Indexed: 06/03/2023]
Abstract
Alternative pre-mRNA splicing, which produces various mRNA isoforms with distinct structures and functions from a single gene, is regulated by specific RNA-binding proteins and is an essential method for regulating gene expression in mammals. Recent studies have shown that abnormal change during neuronal development triggered by splicing mis-regulation is an important feature of various neurological diseases. Polypyrimidine tract binding protein 1 (PTBP1) is a kind of RNA-binding proteins with extensive biological functions. As a well-known splicing regulator, it affects the neuronal development process through its involvement in axon formation, synaptogenesis, and neuronal apoptosis, according to the most recent studies. Here, we summarized the mechanism of alternative splicing, structure and function of PTBP1, and the latest research progress on the role of alternative splicing events regulated by PTBP1 in axon formation, synaptogenesis and neuronal apoptosis, to reveal the mechanism of PTBP1-regulated changes in neuronal development process.
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Affiliation(s)
- Hui-Lin Liu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, PR China; State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, PR China
| | - Xiu-Min Lu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, PR China
| | - Hai-Yan Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, PR China
| | - Kai-Bin Hu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, PR China
| | - Qing-Yun Wu
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, PR China
| | - Ping Liao
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, PR China
| | - Sen Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, PR China
| | - Zai-Yun Long
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, PR China
| | - Yong-Tang Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, PR China.
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21
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Schmeing S, Amrahova G, Bigler K, Chang JY, Openy J, Pal S, Posada L, Gasper R, 't Hart P. Rationally designed stapled peptides allosterically inhibit PTBP1-RNA-binding. Chem Sci 2023; 14:8269-8278. [PMID: 37564416 PMCID: PMC10411625 DOI: 10.1039/d3sc00985h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/28/2023] [Indexed: 08/12/2023] Open
Abstract
The diverse role of the splicing factor PTBP1 in human cells has been widely studied and was found to be a driver for several diseases. PTBP1 binds RNA through its RNA-recognition motifs which lack obvious pockets for inhibition. A unique transient helix has been described to be part of its first RNA-recognition motif and to be important for RNA binding. In this study, we further confirmed the role of this helix and envisioned its dynamic nature as a unique opportunity to develop stapled peptide inhibitors of PTBP1. The peptides were found to be able to inhibit RNA binding via fluorescence polarization assays and directly occupy the helix binding site as observed by protein crystallography. These cell-permeable inhibitors were validated in cellulo to alter the regulation of alternative splicing events regulated by PTBP1. Our study demonstrates transient secondary structures of a protein can be mimicked by stapled peptides to inhibit allosteric mechanisms.
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Affiliation(s)
- Stefan Schmeing
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Gulshan Amrahova
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Katrin Bigler
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Jen-Yao Chang
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Joseph Openy
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Sunit Pal
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Laura Posada
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Raphael Gasper
- Crystallography and Biophysics Unit, Max-Planck-Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Peter 't Hart
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
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22
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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] [MESH Headings] [Grants] [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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23
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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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24
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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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25
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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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26
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Göder A, Quinlan A, Rainey MD, Bennett D, Shamavu D, Corso J, Santocanale C. PTBP1 enforces ATR-CHK1 signaling determining the potency of CDC7 inhibitors. iScience 2023; 26:106951. [PMID: 37378325 PMCID: PMC10291475 DOI: 10.1016/j.isci.2023.106951] [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: 01/24/2023] [Revised: 04/27/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
CDC7 kinase is crucial for DNA replication initiation and fork processing. CDC7 inhibition mildly activates the ATR pathway, which further limits origin firing; however, to date the relationship between CDC7 and ATR remains controversial. We show that CDC7 and ATR inhibitors are either synergistic or antagonistic depending on the degree of inhibition of each individual kinase. We find that Polypyrimidine Tract Binding Protein 1 (PTBP1) is important for ATR activity in response to CDC7 inhibition and genotoxic agents. Compromised PTBP1 expression makes cells defective in RPA recruitment, genomically unstable, and resistant to CDC7 inhibitors. PTBP1 deficiency affects the expression and splicing of many genes indicating a multifactorial impact on drug response. We find that an exon skipping event in RAD51AP1 contributes to checkpoint deficiency in PTBP1-deficient cells. These results identify PTBP1 as a key factor in replication stress response and define how ATR activity modulates the activity of CDC7 inhibitors.
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Affiliation(s)
- Anja Göder
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Aisling Quinlan
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Michael D. Rainey
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Declan Bennett
- School of Mathematical & Statistical Sciences, University of Galway, Galway H91TK33, Ireland
| | - Daniel Shamavu
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Jacqueline Corso
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
| | - Corrado Santocanale
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland
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27
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Hao Y, Hu J, Xue Y, Dowdy SF, Mobley WC, Qian H, Fu XD. Reply to: Ptbp1 deletion does not induce astrocyte-to-neuron conversion. Nature 2023; 618:E8-E13. [PMID: 37286647 DOI: 10.1038/s41586-023-06067-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Yajing Hao
- Department of Cellular and Molecular Medicine, University of California San Diego School of Medicine, La Jolla, CA, USA
| | - Jing Hu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Yuanchao Xue
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Steven F Dowdy
- Department of Cellular and Molecular Medicine, University of California San Diego School of Medicine, La Jolla, CA, USA
| | - William C Mobley
- Department of Neurosciences, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Hao Qian
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
| | - Xiang-Dong Fu
- Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, China.
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28
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Yang R, Feng X, Arias-Cavieres A, Mitchell RM, Polo A, Hu K, Zhong R, Qi C, Zhang RS, Westneat N, Portillo CA, Nobrega MA, Hansel C, Garcia Iii AJ, Zhang X. Upregulation of SYNGAP1 expression in mice and human neurons by redirecting alternative splicing. Neuron 2023; 111:1637-1650.e5. [PMID: 36917980 PMCID: PMC10198817 DOI: 10.1016/j.neuron.2023.02.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 12/20/2022] [Accepted: 02/13/2023] [Indexed: 03/14/2023]
Abstract
The Ras GTPase-activating protein SYNGAP1 plays a central role in synaptic plasticity, and de novo SYNGAP1 mutations are among the most frequent causes of autism and intellectual disability. How SYNGAP1 is regulated during development and how to treat SYNGAP1-associated haploinsufficiency remain challenging questions. Here, we characterize an alternative 3' splice site (A3SS) of SYNGAP1 that induces nonsense-mediated mRNA decay (A3SS-NMD) in mouse and human neural development. We demonstrate that PTBP1/2 directly bind to and promote SYNGAP1 A3SS inclusion. Genetic deletion of the Syngap1 A3SS in mice upregulates Syngap1 protein and alleviates the long-term potentiation and membrane excitability deficits caused by a Syngap1 knockout allele. We further report a splice-switching oligonucleotide (SSO) that converts SYNGAP1 unproductive isoform to the functional form in human iPSC-derived neurons. This study describes the regulation and function of SYNGAP1 A3SS-NMD, the genetic rescue of heterozygous Syngap1 knockout mice, and the development of an SSO to potentially alleviate SYNGAP1-associated haploinsufficiency.
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Affiliation(s)
- Runwei Yang
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Xinran Feng
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Alejandra Arias-Cavieres
- Section of Emergency Medicine, Department of Medicine, Institute for Integrative Physiology, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Robin M Mitchell
- Department of Neurobiology, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Ashleigh Polo
- Section of Emergency Medicine, Department of Medicine, Institute for Integrative Physiology, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Kaining Hu
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Rong Zhong
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Cai Qi
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Rachel S Zhang
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Nathaniel Westneat
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Cristabel A Portillo
- Department of Neurobiology, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA; Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA 92697, USA
| | - Marcelo A Nobrega
- Department of Human Genetics, the University of Chicago, Chicago, IL 60637, USA
| | - Christian Hansel
- Department of Neurobiology, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Alfredo J Garcia Iii
- Section of Emergency Medicine, Department of Medicine, Institute for Integrative Physiology, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Xiaochang Zhang
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA.
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29
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Cabej NR. On the origin and nature of nongenetic information in eumetazoans. Ann N Y Acad Sci 2023. [PMID: 37154677 DOI: 10.1111/nyas.15001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Nongenetic information implies all the forms of biological information not related to genes and DNA in general. Despite the deep scientific relevance of the concept, we currently lack reliable knowledge about its carriers and origins; hence, we still do not understand its true nature. Given that genes are the targets of nongenetic information, it appears that a parsimonious approach to find the ultimate source of that information is to trace back the sequential steps of the causal chain upstream of the target genes up to the ultimate link as the source of the nongenetic information. From this perspective, I examine seven nongenetically determined phenomena: placement of locus-specific epigenetic marks on DNA and histones, changes in snRNA expression patterns, neural induction of gene expression, site-specific alternative gene splicing, predator-induced morphological changes, and cultural inheritance. Based on the available evidence, I propose a general model of the common neural origin of all these forms of nongenetic information in eumetazoans.
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Affiliation(s)
- Nelson R Cabej
- Department of Biology, University of Tirana, Tirana, Albania
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30
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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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31
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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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Bushra S, Lin YN, Joudaki A, Ito M, Ohkawara B, Ohno K, Masuda A. Neural Isoforms of Agrin Are Generated by Reduced PTBP1-RNA Interaction Network Spanning the Neuron-Specific Splicing Regions in AGRN. Int J Mol Sci 2023; 24:ijms24087420. [PMID: 37108583 PMCID: PMC10139058 DOI: 10.3390/ijms24087420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Agrin is a heparan sulfate proteoglycan essential for the clustering of acetylcholine receptors at the neuromuscular junction. Neuron-specific isoforms of agrin are generated by alternative inclusion of three exons, called Y, Z8, and Z11 exons, although their processing mechanisms remain elusive. We found, by inspection of splicing cis-elements into the human AGRN gene, that binding sites for polypyrimidine tract binding protein 1 (PTBP1) were extensively enriched around Y and Z exons. PTBP1-silencing enhanced the coordinated inclusion of Y and Z exons in human SH-SY5Y neuronal cells, even though three constitutive exons are flanked by these alternative exons. Deletion analysis using minigenes identified five PTBP1-binding sites with remarkable splicing repression activities around Y and Z exons. Furthermore, artificial tethering experiments indicated that binding of a single PTBP1 molecule to any of these sites represses nearby Y or Z exons as well as the other distal exons. The RRM4 domain of PTBP1, which is required for looping out a target RNA segment, was likely to play a crucial role in the repression. Neuronal differentiation downregulates PTBP1 expression and promotes the coordinated inclusion of Y and Z exons. We propose that the reduction in the PTPB1-RNA network spanning these alternative exons is essential for the generation of the neuron-specific agrin isoforms.
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Affiliation(s)
- Samira Bushra
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Ying-Ni Lin
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Atefeh Joudaki
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Mikako Ito
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Akio Masuda
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
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33
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Joglekar A, Hu W, Zhang B, Narykov O, Diekhans M, Balacco J, Ndhlovu LC, Milner TA, Fedrigo O, Jarvis ED, Sheynkman G, Korkin D, Ross ME, Tilgner HU. Single-cell long-read mRNA isoform regulation is pervasive across mammalian brain regions, cell types, and development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.02.535281. [PMID: 37066387 PMCID: PMC10103983 DOI: 10.1101/2023.04.02.535281] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
RNA isoforms influence cell identity and function. Until recently, technological limitations prevented a genome-wide appraisal of isoform influence on cell identity in various parts of the brain. Using enhanced long-read single-cell isoform sequencing, we comprehensively analyze RNA isoforms in multiple mouse brain regions, cell subtypes, and developmental timepoints from postnatal day 14 (P14) to adult (P56). For 75% of genes, full-length isoform expression varies along one or more axes of phenotypic origin, underscoring the pervasiveness of isoform regulation across multiple scales. As expected, splicing varies strongly between cell types. However, certain gene classes including neurotransmitter release and reuptake as well as synapse turnover, harbor significant variability in the same cell type across anatomical regions, suggesting differences in network activity may influence cell-type identity. Glial brain-region specificity in isoform expression includes strong poly(A)-site regulation, whereas neurons have stronger TSS regulation. Furthermore, developmental patterns of cell-type specific splicing are especially pronounced in the murine adolescent transition from P21 to P28. The same cell type traced across development shows more isoform variability than across adult anatomical regions, indicating a coordinated modulation of functional programs dictating neural development. As most cell-type specific exons in P56 mouse hippocampus behave similarly in newly generated data from human hippocampi, these principles may be extrapolated to human brain. However, human brains have evolved additional cell-type specificity in splicing, suggesting gain-of-function isoforms. Taken together, we present a detailed single-cell atlas of full-length brain isoform regulation across development and anatomical regions, providing a previously unappreciated degree of isoform variability across multiple scales of the brain.
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Affiliation(s)
- Anoushka Joglekar
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Wen Hu
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | | | - Oleksandr Narykov
- Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA
- Computer Science Department, Worcester Polytechnic Institute, Worcester, MA, USA
- Data Science Program, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Mark Diekhans
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | | | - Lishomwa C Ndhlovu
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Olivier Fedrigo
- Vertebrate Genome Lab, the Rockefeller University, New York, NY
| | - Erich D Jarvis
- Vertebrate Genome Lab, the Rockefeller University, New York, NY
- Laboratory of Neurogenetics of Language, the Rockefeller University, New York, NY
- Howard Hughes Medical Institute, Chevy Chase, MD
| | - Gloria Sheynkman
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
- UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, Virginia, USA
| | - Dmitry Korkin
- Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA
- Computer Science Department, Worcester Polytechnic Institute, Worcester, MA, USA
- Data Science Program, Worcester Polytechnic Institute, Worcester, MA, USA
| | - M Elizabeth Ross
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Hagen U Tilgner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
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34
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Chembazhi UV, Tung WS, Hwang H, Wang Y, Lalwani A, Nguyen K, Bangru S, Yee D, Chin K, Yang J, Kalsotra A, Mei W. PTBP1 controls intestinal epithelial regeneration through post-transcriptional regulation of gene expression. Nucleic Acids Res 2023; 51:2397-2414. [PMID: 36744439 PMCID: PMC10018364 DOI: 10.1093/nar/gkad042] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/06/2023] [Accepted: 01/17/2023] [Indexed: 02/07/2023] Open
Abstract
The intestinal epithelial regeneration is driven by intestinal stem cells under homeostatic conditions. Differentiated intestinal epithelial cells, such as Paneth cells, are capable of acquiring multipotency and contributing to regeneration upon the loss of intestinal stem cells. Paneth cells also support intestinal stem cell survival and regeneration. We report here that depletion of an RNA-binding protein named polypyrimidine tract binding protein 1 (PTBP1) in mouse intestinal epithelial cells causes intestinal stem cell death and epithelial regeneration failure. Mechanistically, we show that PTBP1 inhibits neuronal-like splicing programs in intestinal crypt cells, which is critical for maintaining intestinal stem cell stemness. This function is achieved at least in part through promoting the non-productive splicing of its paralog PTBP2. Moreover, PTBP1 inhibits the expression of an AKT inhibitor PHLDA3 in Paneth cells and permits AKT activation, which presumably maintains Paneth cell plasticity and function in supporting intestinal stem cell niche. We show that PTBP1 directly binds to a CU-rich region in the 3' UTR of Phlda3, which we demonstrate to be critical for downregulating the mRNA and protein levels of Phlda3. Our results thus reveal the multifaceted in vivo regulation of intestinal epithelial regeneration by PTBP1 at the post-transcriptional level.
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Affiliation(s)
| | | | | | - Yuexi Wang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Aryan Lalwani
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Ka Lam Nguyen
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Sushant Bangru
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Danielle Yee
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Kristy Chin
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Jing Yang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Auinash Kalsotra
- Correspondence may also be addressed to Auinash Kalsotra. Tel: +1 217 300 7654; Fax: +1 217 265 0385;
| | - Wenyan Mei
- To whom correspondence should be addressed. Tel: +1 217 244 4077; Fax: 217 333 4628; E-mail:
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35
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Ye R, Hu N, Cao C, Su R, Xu S, Yang C, Zhou X, Xue Y. Capture RIC-seq reveals positional rules of PTBP1-associated RNA loops in splicing regulation. Mol Cell 2023; 83:1311-1327.e7. [PMID: 36958328 DOI: 10.1016/j.molcel.2023.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/10/2023] [Accepted: 02/27/2023] [Indexed: 03/25/2023]
Abstract
RNA-binding proteins (RBPs) bind at different positions of the pre-mRNA molecules to promote or reduce the usage of a particular exon. Seeking to understand the working principle of these positional effects, we develop a capture RIC-seq (CRIC-seq) method to enrich specific RBP-associated in situ proximal RNA-RNA fragments for deep sequencing. We determine hnRNPA1-, SRSF1-, and PTBP1-associated proximal RNA-RNA contacts and regulatory mechanisms in HeLa cells. Unexpectedly, the 3D RNA map analysis shows that PTBP1-associated loops in individual introns preferentially promote cassette exon splicing by accelerating asymmetric intron removal, whereas the loops spanning across cassette exon primarily repress splicing. These "positional rules" can faithfully predict PTBP1-regulated splicing outcomes. We further demonstrate that cancer-related splicing quantitative trait loci can disrupt RNA loops by reducing PTBP1 binding on pre-mRNAs to cause aberrant splicing in tumors. Our study presents a powerful method for exploring the functions of RBP-associated RNA-RNA proximal contacts in gene regulation and disease.
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Affiliation(s)
- Rong Ye
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Naijing Hu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changchang Cao
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Ruibao Su
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shihan Xu
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou, Zhejiang 325003, China
| | - Chen Yang
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou, Zhejiang 325003, China
| | - Xiangtian Zhou
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou, Zhejiang 325003, China
| | - Yuanchao Xue
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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36
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A Simplified and Effective Approach for the Isolation of Small Pluripotent Stem Cells Derived from Human Peripheral Blood. Biomedicines 2023; 11:biomedicines11030787. [PMID: 36979766 PMCID: PMC10045871 DOI: 10.3390/biomedicines11030787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/24/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023] Open
Abstract
Pluripotent stem cells are key players in regenerative medicine. Embryonic pluripotent stem cells, despite their significant advantages, are associated with limitations such as their inadequate availability and the ethical dilemmas in their isolation and clinical use. The discovery of very small embryonic-like (VSEL) stem cells addressed the aforementioned limitations, but their isolation technique remains a challenge due to their small cell size and their efficiency in isolation. Here, we report a simplified and effective approach for the isolation of small pluripotent stem cells derived from human peripheral blood. Our approach results in a high yield of small blood stem cell (SBSC) population, which expresses pluripotent embryonic markers (e.g., Nanog, SSEA-3) and the Yamanaka factors. Further, a fraction of SBSCs also co-express hematopoietic markers (e.g., CD45 and CD90) and/or mesenchymal markers (e.g., CD29, CD105 and PTH1R), suggesting a mixed stem cell population. Finally, quantitative proteomic profiling reveals that SBSCs contain various stem cell markers (CD9, ITGA6, MAPK1, MTHFD1, STAT3, HSPB1, HSPA4), and Transcription reg complex factors (e.g., STAT5B, PDLIM1, ANXA2, ATF6, CAMK1). In conclusion, we present a novel, simplified and effective isolating process that yields an abundant population of small-sized cells with characteristics of pluripotency from human peripheral blood.
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37
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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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38
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Manuel JM, Guilloy N, Khatir I, Roucou X, Laurent B. Re-evaluating the impact of alternative RNA splicing on proteomic diversity. Front Genet 2023; 14:1089053. [PMID: 36845399 PMCID: PMC9947481 DOI: 10.3389/fgene.2023.1089053] [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: 11/03/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Alternative splicing (AS) constitutes a mechanism by which protein-coding genes and long non-coding RNA (lncRNA) genes produce more than a single mature transcript. From plants to humans, AS is a powerful process that increases transcriptome complexity. Importantly, splice variants produced from AS can potentially encode for distinct protein isoforms which can lose or gain specific domains and, hence, differ in their functional properties. Advances in proteomics have shown that the proteome is indeed diverse due to the presence of numerous protein isoforms. For the past decades, with the help of advanced high-throughput technologies, numerous alternatively spliced transcripts have been identified. However, the low detection rate of protein isoforms in proteomic studies raised debatable questions on whether AS contributes to proteomic diversity and on how many AS events are really functional. We propose here to assess and discuss the impact of AS on proteomic complexity in the light of the technological progress, updated genome annotation, and current scientific knowledge.
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Affiliation(s)
- Jeru Manoj Manuel
- Research Center on Aging, Centre Intégré Universitaire de Santé et Services Sociaux de l’Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada,Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Noé Guilloy
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Inès Khatir
- Research Center on Aging, Centre Intégré Universitaire de Santé et Services Sociaux de l’Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada,Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Xavier Roucou
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada,Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke (CRCHUS), Sherbrooke, QC, Canada,Quebec Network for Research on Protein Function Structure and Engineering, PROTEO, Québec, QC, Canada
| | - Benoit Laurent
- Research Center on Aging, Centre Intégré Universitaire de Santé et Services Sociaux de l’Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada,Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada,*Correspondence: Benoit Laurent,
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39
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Iannone C, Kainov Y, Zhuravskaya A, Hamid F, Nojima T, Makeyev EV. PTBP1-activated co-transcriptional splicing controls epigenetic status of pluripotent stem cells. Mol Cell 2023; 83:203-218.e9. [PMID: 36626906 DOI: 10.1016/j.molcel.2022.12.014] [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: 04/01/2022] [Revised: 11/15/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023]
Abstract
Many spliceosomal introns are excised from nascent transcripts emerging from RNA polymerase II (RNA Pol II). The extent of cell-type-specific regulation and possible functions of such co-transcriptional events remain poorly understood. We examined the role of the RNA-binding protein PTBP1 in this process using an acute depletion approach followed by the analysis of chromatin- and RNA Pol II-associated transcripts. We show that PTBP1 activates the co-transcriptional excision of hundreds of introns, a surprising effect given that this protein is known to promote intron retention. Importantly, some co-transcriptionally activated introns fail to complete their splicing without PTBP1. In a striking example, retention of a PTBP1-dependent intron triggers nonsense-mediated decay of transcripts encoding DNA methyltransferase DNMT3B. We provide evidence that this regulation facilitates the natural decline in DNMT3B levels in developing neurons and protects differentiation-specific genes from ectopic methylation. Thus, PTBP1-activated co-transcriptional splicing is a widespread phenomenon mediating epigenetic control of cellular identity.
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Affiliation(s)
- Camilla Iannone
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, UK
| | - Yaroslav Kainov
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, UK
| | - Anna Zhuravskaya
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, UK
| | - Fursham Hamid
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, UK
| | - Takayuki Nojima
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Eugene V Makeyev
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, UK.
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40
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Lan C, Zhang H, Wang K, Liu X, Zhao Y, Guo Z, Zhang N, Zhou Y, Gao M, Gu F, Ma Y. The alternative splicing of intersectin 1 regulated by PTBP1 promotes human glioma progression. Cell Death Dis 2022; 13:835. [PMID: 36171198 PMCID: PMC9519902 DOI: 10.1038/s41419-022-05238-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 01/23/2023]
Abstract
Intersectin 1 (ITSN1) contains two isoforms: ITSN1-S and ITSN1-L, which are highly regulated by alternative splicing. Our previous results showed that the two isoforms of ITSN1 displayed opposite functions: ITSN1-S promoted glioma development, while ITSN1-L exerted an inhibitory role in glioma progression. In this study, our transcriptome analysis using a large glioma cohort indicated that the ratio of ITSN1-S/ITSN1-L was positively correlated with glioma grading and poor prognosis. We identified the RNA-binding protein polypyrimidine tract-binding protein 1 (PTBP1) as an ITSN1 pre-mRNA interaction protein through RNA pull-down assay and RNA immunoprecipitation assay. Knockdown of PTBP1 decreased the ratio of ITSN1-S/ITSN1-L. Minigene reporter assay and mutation analyses further confirmed PTBP1 targeted polypyrimidine sequences on ITSN1 exon 30 (TTGCACTTCAGTATTTT) and promoted the inclusion of ITSN1 exon 30. Subsequently, silencing PTBP1 inhibited glioma cell proliferation, migration, and invasion by down-regulating the ratio of ITSN1-S/ITSN1-L. Taken together, our study provides a novel mechanism that PTBP1 modulates the alternative splicing of ITSN1 and promotes glioma proliferation and motility by up-regulating the ratio of ITSN1-S/ITSN1-L, thereby highlighting that PTBP1 may be an attractive therapeutic target for gliomas.
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Affiliation(s)
- Chungen Lan
- grid.411918.40000 0004 1798 6427Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Huikun Zhang
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Kezhen Wang
- grid.411918.40000 0004 1798 6427Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Xiaoli Liu
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Yawen Zhao
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Zhifang Guo
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Ning Zhang
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Yongxia Zhou
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Manzhi Gao
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Feng Gu
- grid.411918.40000 0004 1798 6427Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Yongjie Ma
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
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Lin X, Liu F, Meng K, Liu H, Zhao Y, Chen Y, Hu W, Luo D. Comprehensive Transcriptome Analysis Reveals Sex-Specific Alternative Splicing Events in Zebrafish Gonads. Life (Basel) 2022; 12:life12091441. [PMID: 36143477 PMCID: PMC9501657 DOI: 10.3390/life12091441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 11/21/2022] Open
Abstract
Alternative splicing is an important way of regulating gene functions in eukaryotes. Several key genes involved in sex determination and gonadal differentiation, such as nr5a1 and ddx4, have sex-biased transcripts between males and females, suggesting a potential regulatory role of alternative splicing in gonads. Currently, the sex-specific alternative splicing events and genes have not been comprehensively studied at the genome-wide level in zebrafish. In this study, through global splicing analysis on three independent sets of RNA-seq data from matched zebrafish testes and ovaries, we identified 120 differentially spliced genes shared by the three datasets, most of which haven’t been reported before. Functional enrichment analysis showed that the GO terms of mRNA processing, mRNA metabolism and microtubule-based process were strongly enriched. The testis- and ovary-biased alternative splicing genes were identified, and part of them (tp53bp1, tpx2, mapre1a, kif2c, and ncoa5) were further validated by RT-PCR. Sequence characteristics analysis suggested that the lengths, GC contents, and splice site strengths of the alternative exons or introns may have different influences in different types of alternative splicing events. Interestingly, we identified an unexpected high proportion (over 70%) of non-frameshift exon-skipping events, suggesting that in these cases the two protein isoforms derived from alternative splicing may both have functions. Furthermore, as a representative example, we found that the alternative splicing of ncoa5 causes the loss of a conserved RRM domain in the short transcript predominantly produced in testes. Our study discovers novel sex-specific alternative splicing events and genes with high reliabilities in zebrafish testes and ovaries, which would provide attractive targets for follow-up studies to reveal the biological significances of alternative splicing events and genes in sex determination and gonadal differentiation.
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Affiliation(s)
- Xing Lin
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fei Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (F.L.); (D.L.)
| | - Kaifeng Meng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Hairong Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
| | - Yuanli Zhao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
| | - Yuanyuan Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Hu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang 524088, China
| | - Daji Luo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, University of Chinese Academy of Sciences, Wuhan 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang 524088, China
- Correspondence: (F.L.); (D.L.)
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42
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Chen C, Shang A, Gao Y, Huang J, Liu G, Cho WC, Li D. PTBPs: An immunomodulatory-related prognostic biomarker in pan-cancer. Front Mol Biosci 2022; 9:968458. [PMID: 36203873 PMCID: PMC9531344 DOI: 10.3389/fmolb.2022.968458] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 08/02/2022] [Indexed: 11/20/2022] Open
Abstract
Background: The polypyrimidine tract-binding protein (PTBP) nuclear ribonucleoprotein family of proteins, including PTBP1, PTBP2 and PTBP3, regulate the process of cell proliferation, differentiation, apoptosis and carcinogenesis. PTBPs exhibit oncogenic effects in certain tumors. However, the role of PTBPs in pan-cancer remains unclear. Our study examined the clinical significance and mechanism of PTBPs in pan-cancer. Methods: We compared the expression of PTBPs in paired and unpaired tissue samples from the Cancer Genome Atlas (TCGA) database. Univariate and multivariate Cox regression, Kaplan–Meier curves, and time-dependent receiver operating characteristic (ROC) curves were used to assess the prognostic significance of PTBPs in pan-cancer. The cBioPortal database also identified genomic abnormalities in PTBPs. TISIDB, TCGA, and Cellminer were used to investigate the relationship between PTBP expression and immune subtypes, immune checkpoint (ICP) genes, tumor mutational burden (TMB), microsatellite instability (MSI), tumor-infiltrating immune cells, and chemosensitivity. cBioPortal was used to search for PTBP co-expressing genes in pan-cancer, and GO and KEGG enrichment analyses were performed to search for PTBP-related signaling pathways. Results:PTBPs were shown to be widely upregulated in human tumor tissues. PTBP1 showed good prognostic value in ACC, KIRP, and LGG; PTBP2 in ACC and KICH; and PTBP3 in ACC, LGG, and PAAD, with AUC >0.7. PTBPs were differentially expressed in tumor immune subtypes and had a strong correlation with tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment (TME). In addition, PTBP expressions were related to ICP, TMB, and MSI, suggesting that these three PTBPs may be potential tumor immunotherapeutic targets and predict the efficacy of immunotherapy. Enrichment analysis of co-expressed genes of PTBPs showed that they may be involved in alternative splicing, cell cycle, cellular senescence, and protein modification. Conclusion: PTBPs are involved in the malignant progression of tumors. PTBP1, PTBP2 and PTBP3 may be potential biomarkers for prognosis and immunotherapy in pan-cancer and may be novel immunotherapeutic targets.
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Affiliation(s)
- Chen Chen
- Department of Laboratory Medicine, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Anquan Shang
- Department of Laboratory Medicine, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yuting Gao
- Department of Laboratory Medicine, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Jingjuan Huang
- Department of Laboratory Medicine, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Gege Liu
- Department of Laboratory Medicine, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - William C. Cho
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong, Hong Kong SAR, China
- *Correspondence: William C. Cho, ; Dong Li,
| | - Dong Li
- Department of Laboratory Medicine, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- *Correspondence: William C. Cho, ; Dong Li,
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43
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Han H, Best AJ, Braunschweig U, Mikolajewicz N, Li JD, Roth J, Chowdhury F, Mantica F, Nabeel-Shah S, Parada G, Brown KR, O'Hanlon D, Wei J, Yao Y, Zid AA, Comsa LC, Jen M, Wang J, Datti A, Gonatopoulos-Pournatzis T, Weatheritt RJ, Greenblatt JF, Wrana JL, Irimia M, Gingras AC, Moffat J, Blencowe BJ. Systematic exploration of dynamic splicing networks reveals conserved multistage regulators of neurogenesis. Mol Cell 2022; 82:2982-2999.e14. [PMID: 35914530 PMCID: PMC10686216 DOI: 10.1016/j.molcel.2022.06.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/16/2022] [Accepted: 06/29/2022] [Indexed: 11/19/2022]
Abstract
Alternative splicing (AS) is a critical regulatory layer; yet, factors controlling functionally coordinated splicing programs during developmental transitions are poorly understood. Here, we employ a screening strategy to identify factors controlling dynamic splicing events important for mammalian neurogenesis. Among previously unknown regulators, Rbm38 acts widely to negatively control neural AS, in part through interactions mediated by the established repressor of splicing, Ptbp1. Puf60, a ubiquitous factor, is surprisingly found to promote neural splicing patterns. This activity requires a conserved, neural-differential exon that remodels Puf60 co-factor interactions. Ablation of this exon rewires distinct AS networks in embryonic stem cells and at different stages of mouse neurogenesis. Single-cell transcriptome analyses further reveal distinct roles for Rbm38 and Puf60 isoforms in establishing neuronal identity. Our results describe important roles for previously unknown regulators of neurogenesis and establish how an alternative exon in a widely expressed splicing factor orchestrates temporal control over cell differentiation.
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Affiliation(s)
- Hong Han
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada.
| | - Andrew J Best
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | | | | | - Jack Daiyang Li
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Jonathan Roth
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Fuad Chowdhury
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Federica Mantica
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Dr. Aiguader, 88, Barcelona 08003, Spain
| | - Syed Nabeel-Shah
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Guillermo Parada
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Kevin R Brown
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Dave O'Hanlon
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Jiarun Wei
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Yuxi Yao
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Abdelrahman Abou Zid
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Institute for Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Lim Caden Comsa
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Mark Jen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Jenny Wang
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Alessandro Datti
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Thomas Gonatopoulos-Pournatzis
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Center for Cancer Research National Cancer Institute, Frederick, MD 21702-1201, USA
| | - Robert J Weatheritt
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia; St. Vincent Clinical School, University of New South Wales, Darlinghurst, NSW 2010, Australia
| | - Jack F Greenblatt
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Jeffrey L Wrana
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Manuel Irimia
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Dr. Aiguader, 88, Barcelona 08003, Spain; Universitat Pompeu Fabra, Barcelona, Spain; ICREA, Barcelona, Spain
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Jason Moffat
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Institute for Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada.
| | - Benjamin J Blencowe
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.
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44
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Cao H, Ji X, Wang Q, Guan X, Wei W, Li Y, Zou W, Liu J. PTBP-1 and TNF-α/NF-κB are involved in repair mechanisms of human umbilical cord mesenchymal stem cell transplantation in mice with spinal cord injury. Am J Transl Res 2022; 14:4443-4456. [PMID: 35958465 PMCID: PMC9360871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVES To explore the possible mechanism of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation in mice after spinal cord hemisection. METHODS Thoracic spinal cord hemisection injuries were performed on adult female Kunming mice. The mice with spinal cord injury (SCI) were injected with hUC-MSCs suspended in normal saline, while the control mice received an equal volume of normal saline. The histological HE staining and Nissl staining were performed 4 and 8 weeks after hUC-MSC transplantation in SCI mice. The Basso-Beattie-Bresnahan (BBB) locomotor rating scale was used to assess functional recovery after SCI. Western blotting was performed to determine the protein expressions. RESULTS hUC-MSCs transplantation decreased cavitation and tissue loss and increased the number of Nissl bodies in the damaged areas of the spinal cord after 4 and 8 weeks. The BBB locomotor performance of the transplanted mice was significantly improved (P<0.01). The wet weight of the injured side of the gastrocnemius muscle was significantly higher in the transplant group than that in the control group. Western blotting showed that TUJ1 and Olig2 expressions were significantly higher in hUC-MSC-grafted mice than those in vehicle controls. Three days after hUC-MSC transplantation, the expressions of TNF-α and NF-κB were higher in MSC-grafted mice than those in vehicle controls. However, 4 weeks after stem cell transplantation, the expressions of these two factors decreased in hUC-MSC-grafted mice compared with those in the vehicle controls. At 8 weeks after hUC-MSC transplantation, the expression of PTBP-1 was decreased in hUC-MSC-grafted mice compared with that in vehicle controls. CONCLUSIONS hUC-MSC transplantation can protect neuron survival, promote myelin repair, and control glial scar formation in SCI mice.
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Affiliation(s)
- Hua Cao
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, The First Affiliated Hospital of Dalian Medical UniversityDalian, Liaoning, China
| | - Xiaofei Ji
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, The First Affiliated Hospital of Dalian Medical UniversityDalian, Liaoning, China
| | - Qi Wang
- Department of Pathology, The Affiliated Sixth People’s Hospital of Dalian Medical UniversityDalian, Liaoning, China
| | - Xin Guan
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, The First Affiliated Hospital of Dalian Medical UniversityDalian, Liaoning, China
| | - Wenjuan Wei
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, The First Affiliated Hospital of Dalian Medical UniversityDalian, Liaoning, China
| | - Ying Li
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, The First Affiliated Hospital of Dalian Medical UniversityDalian, Liaoning, China
| | - Wei Zou
- College of Life Science, Liaoning Normal UniversityDalian, Liaoning, China
| | - Jing Liu
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, The First Affiliated Hospital of Dalian Medical UniversityDalian, Liaoning, China
- Dalian Innovation Institute of Stem Cell and Precision MedicineDalian, Liaoning, China
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45
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Bhat VD, Jayaraj J, Babu K. RNA and neuronal function: the importance of post-transcriptional regulation. OXFORD OPEN NEUROSCIENCE 2022; 1:kvac011. [PMID: 38596700 PMCID: PMC10913846 DOI: 10.1093/oons/kvac011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/03/2022] [Accepted: 05/28/2022] [Indexed: 04/11/2024]
Abstract
The brain represents an organ with a particularly high diversity of genes that undergo post-transcriptional gene regulation through multiple mechanisms that affect RNA metabolism and, consequently, brain function. This vast regulatory process in the brain allows for a tight spatiotemporal control over protein expression, a necessary factor due to the unique morphologies of neurons. The numerous mechanisms of post-transcriptional regulation or translational control of gene expression in the brain include alternative splicing, RNA editing, mRNA stability and transport. A large number of trans-elements such as RNA-binding proteins and micro RNAs bind to specific cis-elements on transcripts to dictate the fate of mRNAs including its stability, localization, activation and degradation. Several trans-elements are exemplary regulators of translation, employing multiple cofactors and regulatory machinery so as to influence mRNA fate. Networks of regulatory trans-elements exert control over key neuronal processes such as neurogenesis, synaptic transmission and plasticity. Perturbations in these networks may directly or indirectly cause neuropsychiatric and neurodegenerative disorders. We will be reviewing multiple mechanisms of gene regulation by trans-elements occurring specifically in neurons.
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Affiliation(s)
- Vandita D Bhat
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
| | - Jagannath Jayaraj
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
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46
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Hoang T, Kim DW, Appel H, Pannullo NA, Leavey P, Ozawa M, Zheng S, Yu M, Peachey NS, Blackshaw S. Genetic loss of function of Ptbp1 does not induce glia-to-neuron conversion in retina. Cell Rep 2022; 39:110849. [PMID: 35705053 PMCID: PMC9619396 DOI: 10.1016/j.celrep.2022.110849] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/29/2022] [Accepted: 04/29/2022] [Indexed: 11/03/2022] Open
Abstract
Direct reprogramming of glia into neurons is a potentially promising approach for the replacement of neurons lost to injury or neurodegenerative disorders. Knockdown of the polypyrimidine tract-binding protein Ptbp1 has been recently reported to induce efficient conversion of retinal Mϋller glia into functional neurons. Here, we use a combination of genetic lineage tracing, single-cell RNA sequencing (scRNA-seq), and electroretinogram analysis to show that selective induction of either heterozygous or homozygous loss-of-function mutants of Ptbp1 in adult retinal Mϋller glia does not lead to any detectable level of neuronal conversion. Only a few changes in gene expression are observed in Mϋller glia following Ptbp1 deletion, and glial identity is maintained. These findings highlight the importance of using genetic manipulation and lineage-tracing methods in studying cell-type conversion.
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Affiliation(s)
- Thanh Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Haley Appel
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nicole A Pannullo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Patrick Leavey
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Manabu Ozawa
- Center for Experimental Medicine and Systems Biology, University of Tokyo, Tokyo, Japan
| | - Sika Zheng
- Division of Biomedical Sciences, University of California, Riverside, CA, USA
| | - Minzhong Yu
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland, OH, USA; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Neal S Peachey
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland, OH, USA; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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47
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Rehn M, Wenzel A, Frank AK, Schuster MB, Pundhir S, Jørgensen N, Vitting-Seerup K, Ge Y, Jendholm J, Michaut M, Schoof EM, Jensen TL, Rapin N, Sapio RT, Andersen KL, Lund AH, Solimena M, Holzenberger M, Pestov DG, Porse BT. PTBP1 promotes hematopoietic stem cell maintenance and red blood cell development by ensuring sufficient availability of ribosomal constituents. Cell Rep 2022; 39:110793. [PMID: 35545054 DOI: 10.1016/j.celrep.2022.110793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 03/14/2022] [Accepted: 04/15/2022] [Indexed: 11/18/2022] Open
Abstract
Ribosomopathies constitute a range of disorders associated with defective protein synthesis mainly affecting hematopoietic stem cells (HSCs) and erythroid development. Here, we demonstrate that deletion of poly-pyrimidine-tract-binding protein 1 (PTBP1) in the hematopoietic compartment leads to the development of a ribosomopathy-like condition. Specifically, loss of PTBP1 is associated with decreases in HSC self-renewal, erythroid differentiation, and protein synthesis. Consistent with its function as a splicing regulator, PTBP1 deficiency results in splicing defects in hundreds of genes, and we demonstrate that the up-regulation of a specific isoform of CDC42 partly mimics the protein-synthesis defect associated with loss of PTBP1. Furthermore, PTBP1 deficiency is associated with a marked defect in ribosome biogenesis and a selective reduction in the translation of mRNAs encoding ribosomal proteins. Collectively, this work identifies PTBP1 as a key integrator of ribosomal functions and highlights the broad functional repertoire of RNA-binding proteins.
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Affiliation(s)
- Matilda Rehn
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Anne Wenzel
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Anne-Katrine Frank
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Mikkel Bruhn Schuster
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Sachin Pundhir
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nanna Jørgensen
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Ying Ge
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Johan Jendholm
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Magali Michaut
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Erwin M Schoof
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; DTU Bioengineering, Danish Technical University, 2800 Kgs. Lyngby, Denmark
| | - Tanja Lyholm Jensen
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nicolas Rapin
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Russell T Sapio
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | | | - Anders H Lund
- Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark
| | - Michele Solimena
- Molecular Diabetology, University Hospital and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany; Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany; German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Martin Holzenberger
- Sorbonne University, INSERM, Research Center Saint-Antoine, CRSA, 75012 Paris, France
| | - Dimitri G Pestov
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Bo Torben Porse
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark.
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48
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Hinkle ER, Wiedner HJ, Torres EV, Jackson M, Black AJ, Blue RE, Harris SE, Guzman BB, Gentile GM, Lee EY, Tsai YH, Parker J, Dominguez D, Giudice J. Alternative splicing regulation of membrane trafficking genes during myogenesis. RNA (NEW YORK, N.Y.) 2022; 28:523-540. [PMID: 35082143 PMCID: PMC8925968 DOI: 10.1261/rna.078993.121] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Alternative splicing transitions occur during organ development, and, in numerous diseases, splicing programs revert to fetal isoform expression. We previously found that extensive splicing changes occur during postnatal mouse heart development in genes encoding proteins involved in vesicle-mediated trafficking. However, the regulatory mechanisms of this splicing-trafficking network are unknown. Here, we found that membrane trafficking genes are alternatively spliced in a tissue-specific manner, with striated muscles exhibiting the highest levels of alternative exon inclusion. Treatment of differentiated muscle cells with chromatin-modifying drugs altered exon inclusion in muscle cells. Examination of several RNA-binding proteins revealed that the poly-pyrimidine tract binding protein 1 (PTBP1) and quaking regulate splicing of trafficking genes during myogenesis, and that removal of PTBP1 motifs prevented PTBP1 from binding its RNA target. These findings enhance our understanding of developmental splicing regulation of membrane trafficking proteins which might have implications for muscle disease pathogenesis.
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Affiliation(s)
- Emma R Hinkle
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Hannah J Wiedner
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Eduardo V Torres
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Micaela Jackson
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Adam J Black
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - R Eric Blue
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Sarah E Harris
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Bryan B Guzman
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Gabrielle M Gentile
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Eunice Y Lee
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Yi-Hsuan Tsai
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Joel Parker
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Daniel Dominguez
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Jimena Giudice
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- McAllister Heart Institute, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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49
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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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50
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Zhao J, Li Z, Puri R, Liu K, Nunez I, Chen L, Zheng S. Molecular profiling of individual FDA-approved clinical drugs identifies modulators of nonsense-mediated mRNA decay. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:304-318. [PMID: 35024243 PMCID: PMC8718828 DOI: 10.1016/j.omtn.2021.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 12/07/2021] [Indexed: 12/12/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) degrades transcripts with premature stop codons. Given the prevalence of nonsense single nucleotide polymorphisms (SNPs) in the general population, it is urgent to catalog the effects of clinically approved drugs on NMD activity: any interference could alter the expression of nonsense SNPs, inadvertently inducing adverse effects. This risk is higher for patients with disease-causing nonsense mutations or an illness linked to dysregulated nonsense transcripts. On the other hand, hundreds of disorders are affected by cellular NMD efficiency and may benefit from NMD-modulatory drugs. Here, we profiled individual FDA-approved drugs for their impact on cellular NMD efficiency using a sensitive method that directly probes multiple endogenous NMD targets for a robust readout of NMD modulation. We found most FDA-approved drugs cause unremarkable effects on NMD, while many elicit clear transcriptional responses. Besides several potential mild NMD modulators, the anticancer drug homoharringtonine (HHT or omacetaxine mepesuccinate) consistently upregulates various endogenous NMD substrates in a dose-dependent manner in multiple cell types. We further showed translation inhibition mediates HHT's NMD effect. In summary, many FDA drugs induce transcriptional changes, and a few impact global NMD, and direct measurement of endogenous NMD substrate expression is robust to monitor cellular NMD.
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Affiliation(s)
- Jingrong Zhao
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Zhelin Li
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Ruchira Puri
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Kelvin Liu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Israel Nunez
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Liang Chen
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Sika Zheng
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
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