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Chen HY, Huang YC, Yeh TH, Chang CW, Shen YJ, Chen YC, Sun MQ, Cheng YC. Dtx2 Deficiency Induces Ependymo-Radial Glial Cell Proliferation and Improves Spinal Cord Motor Function Recovery. Stem Cells Dev 2024. [PMID: 39001828 DOI: 10.1089/scd.2023.0247] [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: 07/15/2024] Open
Abstract
Traumatic injury to the spinal cord can lead to significant, permanent disability. Mammalian spinal cords are not capable of regeneration; in contrast, adult zebrafish are capable of such regeneration, fully recovering motor function. Understanding the mechanisms underlying zebrafish neuroregeneration may provide useful information regarding endogenous regenerative potential and aid in the development of therapeutic strategies in humans. DELTEX proteins (DTXs) regulate a variety of cellular processes. However, their role in neural regeneration has not been described. We found that zebrafish dtx2, encoding Deltex E3 ubiquitin ligase 2, is expressed in ependymo-radial glial cells in the adult spinal cord. After spinal cord injury, the heterozygous dtx2 mutant fish motor function recovered quicker than that of the wild-type controls. The mutant fish displayed increased ependymo-radial glial cell proliferation and augmented motor neuron formation. Moreover, her gene expression, downstream of Notch signaling, increased in Dtx2 mutants. Notch signaling inactivation by dominant-negative Rbpj abolished the increased ependymo-radial glia proliferation caused by Dtx2 deficiency. These results indicate that ependymo-radial glial proliferation is induced by Dtx2 deficiency by activating Notch-Rbpj signaling to improve spinal cord regeneration and motor function recovery.
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Affiliation(s)
- Hao-Yuan Chen
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yin-Cheng Huang
- Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Tu-Hsueh Yeh
- Department of Neurology, Taipei Medical University Hospital, Taipei, Taiwan
- School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chia-Wei Chang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yang-Jin Shen
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- School of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Chieh Chen
- Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Mu-Qun Sun
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
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2
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England SJ, Campbell PC, Banerjee S, Bates RL, Grieb G, Fancher WF, Lewis KE. Transcriptional regulators with broad expression in the zebrafish spinal cord. Dev Dyn 2024. [PMID: 38850245 DOI: 10.1002/dvdy.717] [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: 01/23/2024] [Revised: 04/12/2024] [Accepted: 05/15/2024] [Indexed: 06/10/2024] Open
Abstract
BACKGROUND The spinal cord is a crucial part of the vertebrate CNS, controlling movements and receiving and processing sensory information from the trunk and limbs. However, there is much we do not know about how this essential organ develops. Here, we describe expression of 21 transcription factors and one transcriptional regulator in zebrafish spinal cord. RESULTS We analyzed the expression of aurkb, foxb1a, foxb1b, her8a, homeza, ivns1abpb, mybl2b, myt1a, nr2f1b, onecut1, sall1a, sall3a, sall3b, sall4, sox2, sox19b, sp8b, tsc22d1, wdhd1, zfhx3b, znf804a, and znf1032 in wild-type and MIB E3 ubiquitin protein ligase 1 zebrafish embryos. While all of these genes are broadly expressed in spinal cord, they have distinct expression patterns from one another. Some are predominantly expressed in progenitor domains, and others in subsets of post-mitotic cells. Given the conservation of spinal cord development, and the transcription factors and transcriptional regulators that orchestrate it, we expect that these genes will have similar spinal cord expression patterns in other vertebrates, including mammals and humans. CONCLUSIONS Our data identify 22 different transcriptional regulators that are strong candidates for playing different roles in spinal cord development. For several of these genes, this is the first published description of their spinal cord expression.
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Affiliation(s)
| | - Paul C Campbell
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Santanu Banerjee
- Biological Sciences Department, SUNY-Cortland, Cortland, New York, USA
| | - Richard L Bates
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Ginny Grieb
- Department of Biology, Syracuse University, Syracuse, New York, USA
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England SJ, Campbell PC, Banerjee S, Bates RL, Grieb G, Fancher WF, Lewis KE. Transcriptional Regulators with Broad Expression in the Zebrafish Spinal Cord. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580357. [PMID: 38405913 PMCID: PMC10888778 DOI: 10.1101/2024.02.14.580357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Background The spinal cord is a crucial part of the vertebrate CNS, controlling movements and receiving and processing sensory information from the trunk and limbs. However, there is much we do not know about how this essential organ develops. Here, we describe expression of 21 transcription factors and one transcriptional regulator in zebrafish spinal cord. Results We analyzed the expression of aurkb, foxb1a, foxb1b, her8a, homeza, ivns1abpb, mybl2b, myt1a, nr2f1b, onecut1, sall1a, sall3a, sall3b, sall4, sox2, sox19b, sp8b, tsc22d1, wdhd1, zfhx3b, znf804a, and znf1032 in wild-type and MIB E3 ubiquitin protein ligase 1 zebrafish embryos. While all of these genes are broadly expressed in spinal cord, they have distinct expression patterns from one another. Some are predominantly expressed in progenitor domains, and others in subsets of post-mitotic cells. Given the conservation of spinal cord development, and the transcription factors and transcriptional regulators that orchestrate it, we expect that these genes will have similar spinal cord expression patterns in other vertebrates, including mammals and humans. Conclusions Our data identify 22 different transcriptional regulators that are strong candidates for playing different roles in spinal cord development. For several of these genes, this is the first published description of their spinal cord expression.
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Affiliation(s)
- Samantha J. England
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | - Paul C. Campbell
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | - Santanu Banerjee
- Biological Sciences Department, SUNY-Cortland, Cortland, NY 13045, USA
| | - Richard L. Bates
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | - Ginny Grieb
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | - William F. Fancher
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | - Katharine E. Lewis
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
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Zhang C, Ye W, Zhao M, Long L, Xia D, Fan Z. MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1. Int J Oral Sci 2023; 15:48. [PMID: 37852994 PMCID: PMC10584904 DOI: 10.1038/s41368-023-00253-0] [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: 04/19/2023] [Revised: 09/18/2023] [Accepted: 09/25/2023] [Indexed: 10/20/2023] Open
Abstract
Mesenchymal stem cell (MSC)-based therapy has emerged as a promising treatment for spinal cord injury (SCI), but improving the neurogenic potential of MSCs remains a challenge. Mixed lineage leukemia 1 (MLL1), an H3K4me3 methyltransferases, plays a critical role in regulating lineage-specific gene expression and influences neurogenesis. In this study, we investigated the role and mechanism of MLL1 in the neurogenesis of stem cells from apical papilla (SCAPs). We examined the expression of neural markers, and the nerve repair and regeneration ability of SCAPs using dynamic changes in neuron-like cells, immunofluorescence staining, and a SCI model. We employed a coimmunoprecipitation (Co-IP) assay, real-time RT-PCR, microarray analysis, and chromatin immunoprecipitation (ChIP) assay to investigate the molecular mechanism. The results showed that MLL1 knock-down increased the expression of neural markers, including neurogenic differentiation factor (NeuroD), neural cell adhesion molecule (NCAM), tyrosine hydroxylase (TH), βIII-tubulin and Nestin, and promoted neuron-like cell formation in SCAPs. In vivo, a transplantation experiment showed that depletion of MLL 1 in SCAPs can restore motor function in a rat SCI model. MLL1 can combine with WD repeat domain 5 (WDR5) and WDR5 inhibit the expression of neural markers in SCAPs. MLL1 regulates Hairy and enhancer of split 1 (HES1) expression by directly binds to HES1 promoters via regulating H3K4me3 methylation by interacting with WDR5. Additionally, HES1 enhances the expression of neural markers in SCAPs. Our findings demonstrate that MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1. These results provide a potential therapeutic target for promoting the recovery of motor function in SCI patients.
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Affiliation(s)
- Chen Zhang
- Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
- Department of Dental Emergency, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Weilong Ye
- Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Mengyao Zhao
- Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Lujue Long
- Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Dengsheng Xia
- Department of Dental Emergency, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Zhipeng Fan
- Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China.
- Beijing Laboratory of Oral Health, Capital Medical University, Beijing, China.
- Research Unit of Tooth Development and Regeneration, Chinese Academy of Medical Sciences, Beijing, China.
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Yeh TH, Liu HF, Chiu CC, Cheng ML, Huang GJ, Huang YC, Liu YC, Huang YZ, Lu CS, Chen YC, Chen HY, Cheng YC. PLA2G6 mutations cause motor dysfunction phenotypes of young-onset dystonia-parkinsonism type 14 and can be relieved by DHA treatment in animal models. Exp Neurol 2021; 346:113863. [PMID: 34520727 DOI: 10.1016/j.expneurol.2021.113863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 08/30/2021] [Accepted: 09/08/2021] [Indexed: 10/20/2022]
Abstract
Parkinson's disease (PD), the most common neurodegenerative motor disorder, is currently incurable. Although many studies have provided insights on the substantial influence of genetic factors on the occurrence and development of PD, the molecular mechanism underlying the disease is largely unclear. Previous studies have shown that point mutations in the phospholipase A2 group VI gene (PLA2G6) correlate with young-onset dystonia-parkinsonism type 14 (PARK14). However, limited information is available regarding the pathogenic role of this gene and the mechanism underlying its function. To study the role of PLA2G6 mutations, we first used zebrafish larvae to screen six PLA2G6 mutations and revealed that injection of D331Y, T572I, and R741Q mutation constructs induced phenotypes such as motility defects and reduction in dopaminergic neurons. The motility defects could be alleviated by treatment with L-3, 4-dihydroxyphenylalanine (L-dopa), indicating that these mutations are pathological for PARK14 symptoms. Furthermore, the injection of D331Y and T572I mutation constructs reduced phospholipase activity of PLA2G6 and its lipid metabolites, which confirmed that these two mutations are loss-of-function mutations. Metabolomic analysis revealed that D331Y or T572I mutation led to higher phospholipid and lower docosahexaenoic acid (DHA) levels, indicating that reduced DHA levels are pathological for defective motor functions. Further, a dietary DHA supplement relieved the motility defects in PLA2G6D331Y/D331Y knock-in mice. This result revealed that the D331Y mutation caused defective PLA2G6 phospholipase activity and consequently reduced the DHA level, which is the pathogenic factor responsible for PARK14. The results of this study will facilitate the development of therapeutic strategies for PARK14.
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Affiliation(s)
- Tu-Hsueh Yeh
- Department of Neurology, Taipei Medical University Hospital, Taipei, Taiwan; School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Han-Fang Liu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ching-Chi Chiu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
| | - Mei-Ling Cheng
- Department of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan.; Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan; Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital, Taoyuan City, Taiwan
| | - Guo-Jen Huang
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; Department of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Yin-Cheng Huang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Yu-Chien Liu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ying-Zu Huang
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Chin-Song Lu
- Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan; Section of Movement Disorders, Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Yi-Chieh Chen
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Hao-Yuan Chen
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Chuan Cheng
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.
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Chen L, Wang Z, Gu W, Zhang XX, Ren H, Wu B. Single-Cell Sequencing Reveals Heterogeneity Effects of Bisphenol A on Zebrafish Embryonic Development. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:9537-9546. [PMID: 32644799 DOI: 10.1021/acs.est.0c02428] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The embryonic period is a sensitive window for bisphenol A (BPA) exposure. However, embryonic development is a highly dynamic process with changing cell populations. The heterogeneity effects of BPA on fish embryo cells during development remain unclear. We applied single-cell RNA sequencing to analyze the impact of BPA exposure on transcriptome heterogeneity of 64 683 cells from zebrafish embryos at 8, 12, and 30 h postfertilization (hpf). Thirty-eight cell populations were identified and gene expression profiles of 16 cell populations were significantly altered by BPA. At 8 hpf, BPA mainly influenced the outer layer cell populations of embryos, such as neural plate border and enveloping layer cells. At 12 and 30 hpf, nervous system formation and heart morphogenesis were disturbed. The altered differential processes of the neural plate border, neural crest, and neuronal cells were found to lead to increased neurogenesis in zebrafish larvae. In the forebrain, midbrain, neurons, and optic cells, pathways related to cell division and DNA replication and repair were altered. Moreover, BPA also changed transforming growth factor (TGF) β signaling and heart tube morphogenesis in heart cells, leading to a decreased heartbeat in zebrafish larvae. Our study provides a comprehensive understanding of BPA toxicity on fish embryonic development at a single-cell level.
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Affiliation(s)
- Ling Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, P. R. China
| | - Zhizhi Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, P. R. China
| | - Weiqing Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, P. R. China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, P. R. China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, P. R. China
| | - Bing Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, P. R. China
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Hsieh YC, Chiang MC, Huang YC, Yeh TH, Shih HY, Liu HF, Chen HY, Wang CP, Cheng YC. Pparα deficiency inhibits the proliferation of neuronal and glial precursors in the zebrafish central nervous system. Dev Dyn 2018; 247:1264-1275. [DOI: 10.1002/dvdy.24683] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 09/12/2018] [Accepted: 10/16/2018] [Indexed: 12/28/2022] Open
Affiliation(s)
- Yen-Che Hsieh
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Taoyuan Taiwan
| | - Ming-Chang Chiang
- Department of Life Science; Fu Jen Catholic University; New Taipei City Taiwan
| | - Yin-Cheng Huang
- College of Medicine; Chang Gung University; Taoyuan Taiwan
- Department of Neurosurgery; Chang Gung Memorial Hospital; Linkou, Taoyuan Taiwan
| | - Tu-Hsueh Yeh
- College of Medicine; Chang Gung University; Taoyuan Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital; Linkou, Taoyuan Taiwan
- Section of Movement Disorders, Department of Neurology; Chang Gung Memorial Hospital; Linkou, Taoyuan Taiwan
- Department of Neurology; Taipei Medical University Hospital; Taipei Taiwan
| | - Hung-Yu Shih
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Taoyuan Taiwan
| | - Han-Fang Liu
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Taoyuan Taiwan
| | - Hao-Yuan Chen
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Taoyuan Taiwan
| | - Chien-Ping Wang
- School of Medicine, College of Medicine, Chang Gung University; Taoyuan Taiwan
| | - Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Taoyuan Taiwan
- College of Medicine; Chang Gung University; Taoyuan Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital; Linkou, Taoyuan Taiwan
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Yeh TH, Liu HF, Li YW, Lu CS, Shih HY, Chiu CC, Lin SJ, Huang YC, Cheng YC. C9orf72 is essential for neurodevelopment and motility mediated by Cyclin G1. Exp Neurol 2018. [PMID: 29522758 DOI: 10.1016/j.expneurol.2018.03.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Hexanucleotide repeat expansions in the C9orf72 gene are a common genetic cause of familial and sporadic amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). However, the function of C9orf72 in neural development and the pathogenic mechanism underlying neurodegeneration are unknown. We found that disrupting C9orf72 expression by using C9orf72 constructs that lack the complete DENN domain result in reduced GTPase activity in zebrafish embryos, demonstrating the indispensability of the complete DENN domain. This effect was phenocopied by knocking down endogenous C9orf72 expression by using morpholinos. C9orf72-deficient zebrafish embryos exhibited impaired axonogenesis and motility defects. The C9orf72 deficiency upregulated the expression of tp53 and caused neuronal apoptosis. Knockdown Tp53 in the C9orf72-deficient embryos rescued only the apoptotic phenotype but not the phenotype with axonal and motility defects. The C9orf72 deficiency also induced ccng1 (encodes Cyclin G1) mRNA expression, and injection of a dominant-negative Cyclin G1 construct rescued the axonal impairment, apoptosis, and motility defects in the C9orf72-deficient embryos. Our results revealed the GTPase activity of C9orf72 and demonstrated that Cyclin G1 is an essential downstream mediator for C9orf72 in neural development and motility. Furthermore, downregulating Cyclin G1 was sufficient to rescue all the defects caused by C9orf72 deficiency. In summary, we revealed a novel regulatory mechanism underlying the role of C9orf72 in neurological and motility defects. This result facilitates understanding the function of the C9orf72 gene in the developing nervous system and provides a potential mechanism underlying the pathogenesis of ALS-FTD.
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Affiliation(s)
- Tu-Hsueh Yeh
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan; Section of Movement Disorders, Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan; Department of Neurology, Taipei Medical University Hospital, Taipei, Taiwan; School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Han-Fang Liu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Wen Li
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chin-Song Lu
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan; Section of Movement Disorders, Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Hung-Yu Shih
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ching-Chi Chiu
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Sheng-Jia Lin
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yin-Cheng Huang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan.
| | - Yi-Chuan Cheng
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
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9
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Wu YH, Lee YH, Shih HY, Chen SH, Cheng YC, Tsun-Yee Chiu D. Glucose-6-phosphate dehydrogenase is indispensable in embryonic development by modulation of epithelial-mesenchymal transition via the NOX/Smad3/miR-200b axis. Cell Death Dis 2018; 9:10. [PMID: 29317613 PMCID: PMC5849038 DOI: 10.1038/s41419-017-0005-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 10/02/2017] [Accepted: 10/02/2017] [Indexed: 12/24/2022]
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) is a housekeeping enzyme involved in the pentose phosphate shunt for producing nicotinamide adenine dinucleotide phosphate (NADPH). Severe G6PD deficiency leads to embryonic lethality, but the underlying mechanism is unclear. In the current study, the effects of G6PD on epithelial-mesenchymal transition (EMT), especially during embryonic development, were investigated. The knockdown of G6PD induced morphological changes, accompanied by the suppression of epithelial markers, E-cadherin and β-catenin, in A549 and MDCK cells. Such modulation of EMT was corroborated by the enhancement of migration ability in G6PD-knockdown A549 cells. Zebrafish embryos with g6pd knockdown exhibited downregulation of the E-cadherin/β-catenin adhesion molecules and impaired embryonic development through reduction in epiboly rate and increase in cell shedding at the embryo surface. The dysregulation in zebrafish embryonic development caused by g6pd knockdown could be rescued through human G6PD or CDH1 (E-cadherin gene) cRNA coinjection. The Smad3/miR-200b axis was dysregulated upon G6PD knockdown, and the reconstitution of SMAD3 in G6PD-knockdown A549 cells restored the expression of E-cadherin/β-catenin. The inhibition of NADPH oxidase (NOX) activation through the loss of p22phox signaling was involved in the dysregulation of the Smad3/miR-200b axis upon G6PD knockdown. The reconstitution of G6PD led to the recovery of the regulation of NOX/Smad3/miR-200b signaling and increased the expression of E-cadherin/β-catenin in G6PD-knockdown cells. Thus, these results suggest that in the EMT process, G6PD plays an important regulatory role as an integral component of the NOX/Smad3/miR-200b axis.
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Affiliation(s)
- Yi-Hsuan Wu
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ying-Hsuan Lee
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hung-Yu Shih
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shih-Hsiang Chen
- Department of Pediatric Hematology/Oncology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan. .,Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan.
| | - Daniel Tsun-Yee Chiu
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan. .,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan. .,Department of Pediatric Hematology/Oncology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan.
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Lin SJ, Chiang MC, Shih HY, Hsu LS, Yeh TH, Huang YC, Lin CY, Cheng YC. Regulator of G protein signaling 2 (Rgs2) regulates neural crest development through Pparδ-Sox10 cascade. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:463-474. [PMID: 27979767 DOI: 10.1016/j.bbamcr.2016.12.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 12/08/2016] [Accepted: 12/12/2016] [Indexed: 12/21/2022]
Abstract
Neural crest cells are multipotent progenitors that migrate extensively and differentiate into numerous derivatives. The developmental plasticity and migratory ability of neural crest cells render them an attractive model for studying numerous aspects of cell progression. We observed that zebrafish rgs2 was expressed in neural crest cells. Disrupting Rgs2 expression by using a dominant negative rgs2 construct or rgs2 morpholinos reduced GTPase-activating protein activity, induced the formation of neural crest progenitors, increased the proliferation of nonectomesenchymal neural crest cells, and inhibited the formation of ectomesenchymal neural crest derivatives. The transcription of pparda (which encodes Pparδ, a Wnt-activated transcription factor) was upregulated in Rgs2-deficient embryos, and Pparδ inhibition using a selective antagonist in the Rgs2-deficient embryos repaired neural crest defects. Our results clarify the mechanism through which the Rgs2-Pparδ cascade regulates neural crest development; specifically, Pparδ directly binds to the promoter and upregulates the transcription of the neural crest specifier sox10. This study reveals a unique regulatory mechanism, the Rgs2-Pparδ-Sox10 signaling cascade, and defines a key molecular regulator, Rgs2, in neural crest development.
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Affiliation(s)
- Sheng-Jia Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, Taiwan
| | - Ming-Chang Chiang
- Department of Life Science, College of Science and Engineering, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Hung-Yu Shih
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, Taiwan
| | - Li-Sung Hsu
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung City, Taiwan
| | - Tu-Hsueh Yeh
- Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan; Section of Movement Disorders, Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Yin-Cheng Huang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Ching-Yu Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, Taiwan
| | - Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, Taiwan; Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan.
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11
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Cheng YC, Huang YC, Yeh TH, Shih HY, Lin CY, Lin SJ, Chiu CC, Huang CW, Jiang YJ. Deltex1 is inhibited by the Notch-Hairy/E(Spl) signaling pathway and induces neuronal and glial differentiation. Neural Dev 2015; 10:28. [PMID: 26714454 PMCID: PMC4696291 DOI: 10.1186/s13064-015-0055-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 12/20/2015] [Indexed: 12/23/2022] Open
Abstract
Background Notch signaling has been conserved throughout evolution and plays a fundamental role in various neural developmental processes and the pathogenesis of several human cancers and genetic disorders. However, how Notch signaling regulates various cellular processes remains unclear. Although Deltex proteins have been identified as cytoplasmic downstream elements of the Notch signaling pathway, few studies have been reported on their physiological role. Results We isolated zebrafish deltex1 (dtx1) and showed that this gene is primarily transcribed in the developing nervous system, and its spatiotemporal expression pattern suggests a role in neural differentiation. The transcription of dtx1 was suppressed by the direct binding of the Notch downstream transcription factors Her2 and Her8a. Overexpressing the complete coding sequence of Dtx1 was necessary for inducing neuronal and glial differentiation. By contrast, disrupting Dtx1 expression by using a Dtx1 construct without the RING finger domain reduced neuronal and glial differentiation. This effect was phenocopied by the knockdown of endogenous Dtx1 expression by using morpholinos, demonstrating the essential function of the RING finger domain and confirming the knockdown specificity. Cell proliferation and apoptosis were unaltered in Dtx1-overexpressed and -deficient zebrafish embryos. Examination of the expression of her2 and her8a in embryos with altered Dtx1 expression showed that Dxt1-induced neuronal differentiation did not require a regulatory effect on the Notch–Hairy/E(Spl) pathway. However, both Dtx1 and Notch activation induced glial differentiation, and Dtx1 and Notch activation negatively inhibited each other in a reciprocal manner, which achieves a proper balance for the expression of Dtx1 and Notch to facilitate glial differentiation. We further confirmed that the Dtx1–Notch–Hairy/E(Spl) cascade was sufficient to induce neuronal and glial differentiation by concomitant injection of an active form of Notch with dtx1, which rescued the neuronogenic and gliogenic defects caused by the activation of Notch signaling. Conclusions Our results demonstrated that Dtx1 is regulated by Notch–Hairy/E(Spl) signaling and is a major factor specifically regulating neural differentiation. Thus, our results provide new insights into the mediation of neural development by the Notch signaling pathway. Electronic supplementary material The online version of this article (doi:10.1186/s13064-015-0055-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, 33383, Taiwan. .,Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan.
| | - Yin-Cheng Huang
- Department of Neurosurgery, Chang Gung Memorial Hospital, Chiayi branch, Chiayi, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Tu-Hsueh Yeh
- Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Section of Movement Disorders, Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Hung-Yu Shih
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, 33383, Taiwan
| | - Ching-Yu Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, 33383, Taiwan
| | - Sheng-Jia Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, 33383, Taiwan
| | - Ching-Chi Chiu
- Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan
| | - Ching-Wen Huang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1 Road, Taoyuan, 33383, Taiwan
| | - Yun-Jin Jiang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan
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12
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The transcription factor hairy/E(spl)-related 2 induces proliferation of neural progenitors and regulates neurogenesis and gliogenesis. Dev Biol 2014; 397:116-28. [PMID: 25446033 DOI: 10.1016/j.ydbio.2014.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 10/15/2014] [Accepted: 10/21/2014] [Indexed: 02/06/2023]
Abstract
The study of molecular regulation in neural development provides information to understand how diverse neural cells are generated. It also helps to establish therapeutic strategies for the treatment of neural degenerative disorders and brain tumors. The Hairy/E(spl) family members are potential targets of Notch signaling, which is fundamental to neural cell maintenance, cell fate decisions, and compartment boundary formation. In this study, we isolated a zebrafish homolog of Hairy/E(spl), her2, and showed that this gene is expressed in neural progenitor cells and in the developing nervous system. The expression of her2 required Notch activation, as revealed by a Notch-defective mutant and a chemical inhibitor, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT). The endogenous expression of Her2 was altered by both overexpression and morpholino-knockdown approaches, and the results demonstrated that Her2 was both necessary and sufficient to promote the proliferation of neural progenitors by inhibiting the transcription of the cell cycle inhibitors cdkn1a, cdkn1ba, and cdkn1bb. Her2 knockdown caused premature neuronal differentiation, which indicates that Her2 is essential for inhibiting neuronal differentiation. At a later stage of neural development, Her2 could induce glial differentiation. The overexpression of Her2 constructs lacking the bHLH or WRPW domain phenocopied the effect of the morpholino knockdown, demonstrating the essential function of these two domains and further confirming the knockdown specificity. In conclusion, our data reveal that Her2 promotes progenitor proliferation and maintains progenitor characteristics by inhibiting neuronal differentiation. Together, these two mechanisms ensure the proper development of the neural progenitor cell pool.
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Huang YC, Shih HY, Lin SJ, Chiu CC, Ma TL, Yeh TH, Cheng YC. The epigenetic factor Kmt2a/Mll1 regulates neural progenitor proliferation and neuronal and glial differentiation. Dev Neurobiol 2014; 75:452-62. [PMID: 25284327 DOI: 10.1002/dneu.22235] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 09/14/2014] [Accepted: 09/29/2014] [Indexed: 12/29/2022]
Abstract
Multiple epigenetic factors play a critical role in cell proliferation and differentiation. However, their function in embryogenesis, especially in neural development, is currently unclear. The Trithorax group (TrxG) homolog KMT2A (MLL1) is an important epigenetic regulator during development and has an especially well-defined role in hematopoiesis. Translocation and aberrant expression of KMT2A is often observed in many tumors, indicating its proto-oncogenic character. Here, we show that Kmt2a was essential for neural development in zebrafish embryos. Disrupting the expression of Kmt2a using morpholino antisense oligonucleotides and a dominant-negative variant resulted in neurogenic phenotypes, including downregulated proliferation of neural progenitors, premature differentiation of neurons, and impaired gliogenesis. This study therefore revealed a novel function of Kmt2a in cell proliferation and differentiation, providing further insight into the function of TrxG proteins in neural development and brain tumors.
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Affiliation(s)
- Yin-Cheng Huang
- Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan
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14
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Chen SY, Shih HY, Lin SJ, Hsiao CD, Li ZC, Cheng YC. Etv5a regulates the proliferation of ventral mesoderm cells and the formation of hemato-vascular derivatives. J Cell Sci 2013; 126:5626-34. [PMID: 24101720 DOI: 10.1242/jcs.132613] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Hematopoietic and vascular endothelial cells constitute the circulatory system and are both generated from the ventral mesoderm. However, the molecules and signaling pathways involved in ventral mesoderm formation and specification remain unclear. We found that zebrafish etv5a was expressed in the ventral mesoderm during gastrulation. Knockdown of Etv5a using morpholinos increased the proliferation of ventral mesoderm cells and caused defects in hematopoietic derivatives and in vascular formation. By contrast, the formation of other mesodermal derivatives, such as pronephros, somites and the gut wall, was not affected. Knockdown specificity was further confirmed by overexpression of an etv5a construct lacking its acidic domain. In conclusion, our data reveal that etv5a is essential for the inhibition of ventral mesoderm cell proliferation and for the formation of the hemato-vascular lineage.
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Affiliation(s)
- Shin-Yi Chen
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Taoyuan 33383, Taiwan
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15
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Tissue factor pathway inhibitor-2: a novel gene involved in zebrafish central nervous system development. Dev Biol 2013; 381:38-49. [PMID: 23796905 DOI: 10.1016/j.ydbio.2013.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/24/2013] [Accepted: 06/12/2013] [Indexed: 01/18/2023]
Abstract
Tissue factor pathway inhibitor-2 (Tfpi-2) is an important serine protease inhibitor in the extracellular matrix (ECM), but its precise physiological significance remains unknown. This work is part of a series of studies intended to investigate functional roles of Tfpi-2 and explore the underlying molecular mechanisms. First, we cloned and identified zebrafish Tfpi-2 (zTfpi-2) as an evolutionarily conserved protein essential for zebrafish development. We also demonstrated that ztfpi-2 is mainly expressed in the central nervous system (CNS) of zebrafish, and embryonic depletion of ztfpi-2 caused severe CNS defects. In addition, changes of neural markers, including pax2a, egr2b, huC, ngn1, gfap and olig2, confirmed the presence of developmental abnormalities in the relevant regions of ztfpi-2 morphants. Using microarray analysis, we found that members of the Notch pathway, especially her4 and mib, which mediate lateral inhibition in CNS development, were also downregulated. Intriguingly, both her4 and mib were able to partially rescue the ztfpi-2 morphant phenotype. Furthermore, Morpholino knockdown of ztfpi-2 resulted in upregulation of neuronal markers while downregulation of glial markers, providing evidence that the Notch pathway is probably involved in ztfpi-2-mediated CNS development.
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16
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Cheng YC, Scotting PJ, Hsu LS, Lin SJ, Shih HY, Hsieh FY, Wu HL, Tsao CL, Shen CJ. Zebrafish rgs4 is essential for motility and axonogenesis mediated by Akt signaling. Cell Mol Life Sci 2013; 70:935-50. [PMID: 23052218 PMCID: PMC11113239 DOI: 10.1007/s00018-012-1178-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 12/21/2022]
Abstract
The schizophrenia susceptibility gene, Rgs4, is one of the most intensively studied regulators of G-protein signaling members, well known to be fundamental in regulating neurotransmission. However, little is known about its role in the developing nervous system. We have isolated zebrafish rgs4 and shown that it is transcribed in the developing nervous system. Rgs4 knockdown did not affect neuron number and patterning but resulted in locomotion defects and aberrant development of axons. This was confirmed using a selective Rgs4 inhibitor, CCG-4986. Rgs4 knockdown also attenuated the level of phosphorylated-Akt1, and injection of constitutively-activated AKT1 rescued the motility defects and axonal phenotypes in the spinal cord but not in the hindbrain and trigeminal neurons. Our in vivo analysis reveals a novel role for Rgs4 in regulating axonogenesis during embryogenesis, which is mediated by another schizophrenia-associated gene, Akt1, in a region-specific manner.
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Affiliation(s)
- Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang Gung University, Taoyuan, 33383, Taiwan.
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17
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Hsieh FY, Ma TL, Shih HY, Lin SJ, Huang CW, Wang HY, Cheng YC. Dner inhibits neural progenitor proliferation and induces neuronal and glial differentiation in zebrafish. Dev Biol 2013; 375:1-12. [PMID: 23328254 DOI: 10.1016/j.ydbio.2013.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 12/17/2012] [Accepted: 01/02/2013] [Indexed: 11/19/2022]
Abstract
Delta/notch-like epidermal growth factor (EGF)-related receptor (DNER) is a single-pass transmembrane protein found to be a novel ligand in the Notch signaling pathway. Its function was previously characterized in the developing cerebellum and inner ear hair cells. In this study, we isolated a zebrafish homolog of DNER and showed that this gene is expressed in the developing nervous system. Overexpression of dner or the intracellular domain of dner was sufficient to inhibit the proliferation of neural progenitors and induce neuronal and glial differentiation. In contrast, the knockdown of endogenous Dner expression using antisense morpholino oligonucleotides increased the proliferation of neural progenitors and maintained neural cells in a progenitor status through inhibition of neuronal and glial differentiation. Through analysis of the antagonistic effect on the Delta ligand and the role of the potential downstream mediator Deltex1, we showed that Dner acts in Notch-dependent and Notch-independent manner. This is the first study to demonstrate a role for Dner in neural progenitors and neuronal differentiation and provides new insights into mediation of neuronal development and differentiation by the Notch signaling pathway.
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Affiliation(s)
- Fu-Yu Hsieh
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang Gung University, Taoyuan 333, Taiwan
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18
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Cheng YC, Hsieh FY, Chiang MC, Scotting PJ, Shih HY, Lin SJ, Wu HL, Lee HT. Akt1 mediates neuronal differentiation in zebrafish via a reciprocal interaction with notch signaling. PLoS One 2013; 8:e54262. [PMID: 23342113 PMCID: PMC3544797 DOI: 10.1371/journal.pone.0054262] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 12/10/2012] [Indexed: 12/12/2022] Open
Abstract
Akt1 is well known for its role in regulating cell proliferation, differentiation, and apoptosis and is implicated in tumors and several neurological disorders. However, the role of Akt1 in neural development has not been well defined. We have isolated zebrafish akt1 and shown that this gene is primarily transcribed in the developing nervous system, and its spatiotemporal expression pattern suggests a role in neural differentiation. Injection of akt1 morpholinos resulted in loss of neuronal precursors with a concomitant increase in post-mitotic neurons, indicating that knockdown of Akt1 is sufficient to cause premature differentiation of neurons. A similar phenotype was observed in embryos deficient for Notch signaling. Both the ligand (deltaA) and the downstream target of Notch (her8a) were downregulated in akt1 morphants, indicating that Akt1 is required for Delta-Notch signaling. Furthermore, akt1 expression was downregulated in Delta-Notch signaling-deficient embryos and could be induced by constitutive activation of Notch signaling. In addition, knockdown of Akt1 was able to nullify the inhibition of neuronal differentiation caused by constitutive activation of Notch signaling. Taken together, these results provide in vivo evidence that Akt1 interacts with Notch signaling reciprocally and provide an explanation of why Akt1 is essential for the inhibition of neuronal differentiation.
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Affiliation(s)
- Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
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Hung FC, Cheng YC, Sun NK, Chao CCK. Identification and functional characterization of zebrafish Gas7 gene in early development. J Neurosci Res 2012; 91:51-61. [PMID: 23086717 DOI: 10.1002/jnr.23145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 08/07/2012] [Accepted: 08/22/2012] [Indexed: 12/17/2022]
Abstract
Growth arrest-specific 7 (Gas7) is preferentially expressed in the nervous system and plays an important role during neuritogenesis in mammals. However, the structure and function of Gas7 homologs have not been studied in nonmammalian vertebrates used as models. In this report, we identify a Gas7 gene in zebrafish that we termed zfGas7. The transcript of this gene was produced by canonical splicing, and its protein product contained a Fes/CIP4 homology and a coiled-coil domain. In early zebrafish embryos, RT-PCR analyses revealed that zfGas7 was initially expressed at 5.3 hr postfertilization (hpf), followed by an increase of expression at 10 hpf and further accumulation during somitogenesis at 48 hpf. Spatiotemporal analyses further showed that Gas7 mRNA was detected in the brain, somite, and posterior presomitic mesoderm regions during somitogenesis. At 36 hpf, zfGas7 mRNA was detected in the brain and somite but was later found only in neuronal clusters of the brain at 52 hpf. Gas7 knockdown with morpholino antisense oligonucleotides (Gas7MO) reduced the number of HuC-positive neurons in the trigeminal and statoacoustic ganglions and produced deformed phenotypes, such as flattening of the top of the head. Notably, the neuron reduction and deformed phenotypes observed in Gas7MO embryos were partially rescued by ectopic expression of Gas7. Because altered somitogenesis and pigmentation were also found in the morphants, the neuronal phenotypes observed likely are due to a general developmental delay of embryogenesis. These results indicate that Gas7 is expressed in neuronal cells but is not specifically required for neuronal development in vertebrates.
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Affiliation(s)
- Feng-Chun Hung
- Department of Biochemistry and Molecular Biology, Chang Gung University, Gueishan, Taiwan, Republic of China
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