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Gao M, Wang K, Zhao H. GABAergic neurons maturation is regulated by a delicate network. Int J Dev Neurosci 2023; 83:3-15. [PMID: 36401305 DOI: 10.1002/jdn.10242] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 10/25/2022] [Accepted: 11/13/2022] [Indexed: 11/21/2022] Open
Abstract
Gamma-aminobutyric acid-expressing (GABAergic) neurons are implicated in a variety of neuropsychiatric disorders, such as epilepsy, anxiety, autism, and other pathological processes, including cerebral ischemia injury and drug addiction. Therefore, GABAergic neuronal processes warrant further research. The development of GABAergic neurons is a tightly controlled process involving the activity of multiple transcription and growth factors. Here, we focus on the gene expression pathways and the molecular modulatory networks that are engaged during the development of GABAergic neurons with the goal of exploring regulatory mechanisms that influence GABAergic neuron fate (i.e., maturation). Overall, we hope to provide a basis for clarifying the pathogenesis of neurodegenerative disorders.
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Affiliation(s)
- Mingxing Gao
- Department of Histology and Embryology, School of Basic Medical Science, Jilin University, Changchun, Jilin, China
| | - Kaizhong Wang
- Department of Thoracic Surgery, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Hui Zhao
- Department of Histology and Embryology, School of Basic Medical Science, Jilin University, Changchun, Jilin, China
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2
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Hulme AJ, Maksour S, St-Clair Glover M, Miellet S, Dottori M. Making neurons, made easy: The use of Neurogenin-2 in neuronal differentiation. Stem Cell Reports 2021; 17:14-34. [PMID: 34971564 PMCID: PMC8758946 DOI: 10.1016/j.stemcr.2021.11.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/27/2021] [Accepted: 11/29/2021] [Indexed: 01/01/2023] Open
Abstract
Directed neuronal differentiation of human pluripotent stem cells (hPSCs), neural progenitors, or fibroblasts using transcription factors has allowed for the rapid and highly reproducible differentiation of mature and functional neurons. Exogenous expression of the transcription factor Neurogenin-2 (NGN2) has been widely used to generate different populations of neurons, which have been used in neurodevelopment studies, disease modeling, drug screening, and neuronal replacement therapies. Could NGN2 be a “one-glove-fits-all” approach for neuronal differentiations? This review summarizes the cellular roles of NGN2 and describes the applications and limitations of using NGN2 for the rapid and directed differentiation of neurons.
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Affiliation(s)
- Amy J Hulme
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; School of Medicine, University of Wollongong, Wollongong, NSW, Australia; Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Simon Maksour
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; School of Medicine, University of Wollongong, Wollongong, NSW, Australia; Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Mitchell St-Clair Glover
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; School of Medicine, University of Wollongong, Wollongong, NSW, Australia; Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Sara Miellet
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; School of Medicine, University of Wollongong, Wollongong, NSW, Australia; Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Mirella Dottori
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; School of Medicine, University of Wollongong, Wollongong, NSW, Australia; Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia.
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3
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Zhou M, Tao X, Sui M, Cui M, Liu D, Wang B, Wang T, Zheng Y, Luo J, Mu Y, Wan F, Zhu LQ, Zhang B. Reprogramming astrocytes to motor neurons by activation of endogenous Ngn2 and Isl1. Stem Cell Reports 2021; 16:1777-1791. [PMID: 34171285 PMCID: PMC8282467 DOI: 10.1016/j.stemcr.2021.05.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/27/2021] [Accepted: 05/27/2021] [Indexed: 12/13/2022] Open
Abstract
Central nervous system injury and neurodegenerative diseases cause irreversible loss of neurons. Overexpression of exogenous specific transcription factors can reprogram somatic cells into functional neurons for regeneration and functional reconstruction. However, these practices are potentially problematic due to the integration of vectors into the host genome. Here, we showed that the activation of endogenous genes Ngn2 and Isl1 by CRISPRa enabled reprogramming of mouse spinal astrocytes and embryonic fibroblasts to motor neurons. These induced neurons showed motor neuronal morphology and exhibited electrophysiological activities. Furthermore, astrocytes in the spinal cord of the adult mouse can be converted into motor neurons by this approach with high efficiency. These results demonstrate that the activation of endogenous genes is sufficient to induce astrocytes into functional motor neurons in vitro and in vivo. This direct neuronal reprogramming approach may provide a novel potential therapeutic strategy for treating neurodegenerative diseases and spinal cord injury.
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Affiliation(s)
- Meiling Zhou
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoqing Tao
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Wuhan Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan 430056, China
| | - Ming Sui
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Mengge Cui
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Dan Liu
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Beibei Wang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ting Wang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yunjie Zheng
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Juan Luo
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yangling Mu
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Feng Wan
- Department of Neurosurgery, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ling-Qiang Zhu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Bin Zhang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China; Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, Huazhong University of Science and Technology, Wuhan 430030, China.
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4
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Ndyabawe K, Cipriano M, Zhao W, Haidekker M, Yao K, Mao L, Kisaalita WS. Brain-on-a-Chip Device for Modeling Multiregional Networks. ACS Biomater Sci Eng 2020; 7:350-359. [PMID: 33320530 DOI: 10.1021/acsbiomaterials.0c00895] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Animal models are frequently used in drug discovery because they represent a mammalian in vivo model system, they are the closest approximation to the human brain, and experimentation in humans is not ethical. Working with postmortem human brain samples is challenging and developing human in vitro systems, which mimic the in vivo human brain, has been challenging. However, the use of animal models in drug discovery for human neurological diseases is currently under scrutiny because data from animal models has come with variations due to genetic differences. Evidence from the literature suggests that techniques to reconstruct multiple neurotransmission projections, which characterize neurological disease circuits in humans, in vitro, have not been demonstrated. This paper presents a multicompartment microdevice for patterning neurospheres and specification of neural stem cell fate toward networks of multiple neuronal phenotypes. We validated our design by specification of human neural stem cells to dopaminergic and GABAergic neurons in different compartments of the device, simultaneously. The neurospheres formed unrestricted robust neuronal circuits between arrays of neurospheres in all compartments of the device. Such a device design may provide a basis for formation of multineurotransmission circuits to model functional connectivity between specific human brain regions, in vitro, using human-derived neural stem cells. This work finds relevance in neurological disease modeling and drug screening using human cell-based assays and may provide the impetus for shifting from animal-based models.
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5
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Xu Z, Su S, Zhou S, Yang W, Deng X, Sun Y, Li L, Li Y. How to reprogram human fibroblasts to neurons. Cell Biosci 2020; 10:116. [PMID: 33062254 PMCID: PMC7549215 DOI: 10.1186/s13578-020-00476-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 09/15/2020] [Indexed: 12/13/2022] Open
Abstract
Destruction and death of neurons can lead to neurodegenerative diseases. One possible way to treat neurodegenerative diseases and damage of the nervous system is replacing damaged and dead neurons by cell transplantation. If new neurons can replace the lost neurons, patients may be able to regain the lost functions of memory, motor, and so on. Therefore, acquiring neurons conveniently and efficiently is vital to treat neurological diseases. In recent years, studies on reprogramming human fibroblasts into neurons have emerged one after another, and this paper summarizes all these studies. Scientists find small molecules and transcription factors playing a crucial role in reprogramming and inducing neuron production. At the same time, both the physiological microenvironment in vivo and the physical and chemical factors in vitro play an essential role in the induction of neurons. Therefore, this paper summarized and analyzed these relevant factors. In addition, due to the unique advantages of physical factors in the process of reprogramming human fibroblasts into neurons, such as safe and minimally invasive, it has a more promising application prospect. Therefore, this paper also summarizes some successful physical mechanisms of utilizing fibroblasts to acquire neurons, which will provide new ideas for somatic cell reprogramming.
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Affiliation(s)
- Ziran Xu
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, 130021 People's Republic of China
| | - Shengnan Su
- The Second Hospital of Jilin University, Jilin, Changchun, 130041 China
| | - Siyan Zhou
- Department of Stomatology, The First Hospital of Jilin University, Changchun, 130021 People's Republic of China
| | - Wentao Yang
- Norman Bethune College of Medicine, Jilin University, Changchun, 130021 People's Republic of China
| | - Xin Deng
- Norman Bethune College of Medicine, Jilin University, Changchun, 130021 People's Republic of China
| | - Yingying Sun
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, 130021 People's Republic of China.,Department of Stomatology, The First Hospital of Jilin University, Changchun, 130021 People's Republic of China
| | - Lisha Li
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, 130021 People's Republic of China
| | - Yulin Li
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, 130021 People's Republic of China
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6
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Song M, Kim H, Park S, Kwon H, Joung I, Kim Kwon Y. Aucubin Promotes Differentiation of Neural Precursor Cells into GABAergic Neurons. Exp Neurobiol 2018; 27:112-119. [PMID: 29731677 PMCID: PMC5934542 DOI: 10.5607/en.2018.27.2.112] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 12/13/2022] Open
Abstract
Aucubin is a small compound naturally found in traditional medicinal herbs with primarily anti-inflammatory and protective effects. In the nervous system, aucubin is reported to be neuroprotective by enhancing neuronal survival and inhibiting apoptotic cell death in cultures and disease models. Our previous data, however, suggest that aucubin facilitates neurite elongation in cultured hippocampal neurons and axonal regrowth in regenerating sciatic nerves. Here, we investigated whether aucubin facilitates the differentiation of neural precursor cells (NPCs) into specific types of neurons. In NPCs cultured primarily from the rat embryonic hippocampus, aucubin significantly elevated the number of GAD65/67 immunoreactive cells and the expression of GAD65/67 proteins was upregulated dramatically by more than three-fold at relatively low concentrations of aucubin (0.01 µM to 10 µM). The expression of both NeuN and vGluT1 of NPCs, the markers for neurons and glutamatergic cells, respectively, and the number of vGluT1 immunoreactive cells also increased with higher concentrations of aucubin (1 µM and 10 µM), but the ratio of the increases was largely lower than GAD expression and GAD immunoreactive cells. The GABAergic differentiation of pax6-expressing late NPCs into GABA-producing cells was further supported in cortical NPCs primarily cultured from transgenic mouse brains, which express recombinant GFP under the control of pax6 promoter. The results suggest that aucubin can be developed as a therapeutic candidate for neurodegenerative disorders caused by the loss of inhibitory GABAergic neurons.
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Affiliation(s)
- Miyeoun Song
- Department of Life and Nanopharmarceutical Science, Kyung Hee University, Seoul 02447, Korea
| | - Hyomin Kim
- Department of Life and Nanopharmarceutical Science, Kyung Hee University, Seoul 02447, Korea
| | - Sujin Park
- Department of Life and Nanopharmarceutical Science, Kyung Hee University, Seoul 02447, Korea
| | - Hyockman Kwon
- Department of Biosciences and Biotechnology, Hankuk University of Foreign Studies, Yongin 17035, Korea
| | - Insil Joung
- Department of Biological Sciences, Hanseo University, Seosan 31962, Korea
| | - Yunhee Kim Kwon
- Department of Life and Nanopharmarceutical Science, Kyung Hee University, Seoul 02447, Korea.,Department of Biology, Kyung Hee University, Seoul 02447, Korea
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7
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Qin H, Zhao A, Fu X. Small molecules for reprogramming and transdifferentiation. Cell Mol Life Sci 2017; 74:3553-3575. [PMID: 28698932 PMCID: PMC11107793 DOI: 10.1007/s00018-017-2586-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 06/26/2017] [Accepted: 06/28/2017] [Indexed: 01/15/2023]
Abstract
Pluripotency reprogramming and transdifferentiation induced by transcription factors can generate induced pluripotent stem cells, adult stem cells or specialized cells. However, the induction efficiency and the reintroduction of exogenous genes limit their translation into clinical applications. Small molecules that target signaling pathways, epigenetic modifications, or metabolic processes can regulate cell development, cell fate, and function. In the recent decade, small molecules have been widely used in reprogramming and transdifferentiation fields, which can promote the induction efficiency, replace exogenous genes, or even induce cell fate conversion alone. Small molecules are expected as novel approaches to generate new cells from somatic cells in vitro and in vivo. Here, we will discuss the recent progress, new insights, and future challenges about the use of small molecules in cell fate conversion.
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Affiliation(s)
- Hua Qin
- Tianjin Medical University, Tianjin, 300070, China
| | - Andong Zhao
- Tianjin Medical University, Tianjin, 300070, China
| | - Xiaobing Fu
- Key Laboratory of Wound Repair and Regeneration of PLA, The First Hospital Affiliated to the PLA General Hospital, 51 Fu Cheng Road, Haidian District, Beijing, 100048, China.
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8
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NEUROD2 Regulates Stim1 Expression and Store-Operated Calcium Entry in Cortical Neurons. eNeuro 2017; 4:eN-NWR-0255-16. [PMID: 28303257 PMCID: PMC5343279 DOI: 10.1523/eneuro.0255-16.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 01/18/2017] [Accepted: 01/25/2017] [Indexed: 12/26/2022] Open
Abstract
Calcium signaling controls many key processes in neurons, including gene expression, axon guidance, and synaptic plasticity. In contrast to calcium influx through voltage- or neurotransmitter-gated channels, regulatory pathways that control store-operated calcium entry (SOCE) in neurons are poorly understood. Here, we report a transcriptional control of Stim1 (stromal interaction molecule 1) gene, which is a major sensor of endoplasmic reticulum (ER) calcium levels and a regulator of SOCE. By using a genome-wide chromatin immunoprecipitation and sequencing approach in mice, we find that NEUROD2, a neurogenic transcription factor, binds to an intronic element within the Stim1 gene. We show that NEUROD2 limits Stim1 expression in cortical neurons and consequently fine-tunes the SOCE response upon depletion of ER calcium. Our findings reveal a novel mechanism that regulates neuronal calcium homeostasis during cortical development.
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9
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Kim YM, Sim UC, Shin Y, Kim Kwon Y. Aucubin promotes neurite outgrowth in neural stem cells and axonal regeneration in sciatic nerves. Exp Neurobiol 2014; 23:238-45. [PMID: 25258571 PMCID: PMC4174615 DOI: 10.5607/en.2014.23.3.238] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 03/06/2014] [Accepted: 03/06/2014] [Indexed: 11/23/2022] Open
Abstract
Aucubin is an iridoid glycoside with a wide range of biological activities, including anti-inflammatory, anti-microbial, anti-algesic as well as anti-tumor activities. Recently, it has been shown that aucubin prevents neuronal death in the hippocampal CA1 region in rats with diabetic encephalopathy. In addition, it has protective effects on H2O2-induced apoptosis in PC12 cells. We have shown here that aucubin promotes neuronal differentiation and neurite outgrowth in neural stem cells cultured primarily from the rat embryonic hippocampus. We also investigated whether aucubin facilitates axonal elongation in the injured peripheral nervous system. Aucubin promoted lengthening and thickness of axons and re-myelination at 3 weeks after sciatic nerve injury. These results indicate that administration of aucubin improved nerve regeneration in the rat model of sciatic nerve injury, suggesting that aucubin may be a useful therapeutic compound for the human peripheral nervous system after various nerve injuries.
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Affiliation(s)
- Yong Min Kim
- Department of Biology, Kyunghee University, Seoul 130-701, Korea
| | - U-Cheol Sim
- Department of Biology, Kyunghee University, Seoul 130-701, Korea
| | - Yongsung Shin
- Department of Biology, Kyunghee University, Seoul 130-701, Korea. ; Department of Life and Nanopharmaceutical Science, Kyunghee University, Seoul 130-701, Korea
| | - Yunhee Kim Kwon
- Department of Biology, Kyunghee University, Seoul 130-701, Korea. ; Department of Life and Nanopharmaceutical Science, Kyunghee University, Seoul 130-701, Korea
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10
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Yuan L, Hassan BA. Neurogenins in brain development and disease: an overview. Arch Biochem Biophys 2014; 558:10-3. [PMID: 24950022 DOI: 10.1016/j.abb.2014.05.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/25/2014] [Accepted: 05/28/2014] [Indexed: 11/25/2022]
Abstract
The production of neurons, astrocytes and oligodendrocytes is regulated by a group of transcription factors, which determine cell fates and specify subtype identities in the nervous system. Here we focus on profiling the distinct roles of Neurogenin (Ngn or Neurog) family members during the neuronal development. Ngn proteins are tightly regulated to be expressed at defined times and positions of different progenitor cell pools. In addition to their well-elucidated proneural function, Ngn proteins play various critical roles to specify or maintain cell fate and regulate neurite outgrowth and targeting in the central nervous system. Finally, Ngns have been associated with neuronal disorders. Therefore understanding the function and regulation of Ngns will not only improve the understanding of the molecular mechanism underlying the development of nervous system, but may also provide insight into neuronal disease.
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Affiliation(s)
- Liqun Yuan
- VIB Center for the Biology of Disease, VIB, 3000 Leuven, Belgium; Center for Human Genetics, University of Leuven School of Medicine, 3000 Leuven, Belgium
| | - Bassem A Hassan
- VIB Center for the Biology of Disease, VIB, 3000 Leuven, Belgium; Center for Human Genetics, University of Leuven School of Medicine, 3000 Leuven, Belgium.
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11
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Yi SH, He XB, Rhee YH, Park CH, Takizawa T, Nakashima K, Lee SH. Foxa2 acts as a co-activator potentiating expression of the Nurr1-induced DA phenotype via epigenetic regulation. Development 2014; 141:761-72. [PMID: 24496614 DOI: 10.1242/dev.095802] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Understanding how dopamine (DA) phenotypes are acquired in midbrain DA (mDA) neuron development is important for bioassays and cell replacement therapy for mDA neuron-associated disorders. Here, we demonstrate a feed-forward mechanism of mDA neuron development involving Nurr1 and Foxa2. Nurr1 acts as a transcription factor for DA phenotype gene expression. However, Nurr1-mediated DA gene expression was inactivated by forming a protein complex with CoREST, and then recruiting histone deacetylase 1 (Hdac1), an enzyme catalyzing histone deacetylation, to DA gene promoters. Co-expression of Nurr1 and Foxa2 was established in mDA neuron precursor cells by a positive cross-regulatory loop. In the presence of Foxa2, the Nurr1-CoREST interaction was diminished (by competitive formation of the Nurr1-Foxa2 activator complex), and CoREST-Hdac1 proteins were less enriched in DA gene promoters. Consequently, histone 3 acetylation (H3Ac), which is responsible for open chromatin structures, was strikingly increased at DA phenotype gene promoters. These data establish the interplay of Nurr1 and Foxa2 as the crucial determinant for DA phenotype acquisition during mDA neuron development.
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Affiliation(s)
- Sang-Hoon Yi
- Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul 133-791, Korea
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12
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Ascl1 as a novel player in the Ptf1a transcriptional network for GABAergic cell specification in the retina. PLoS One 2014; 9:e92113. [PMID: 24643195 PMCID: PMC3958475 DOI: 10.1371/journal.pone.0092113] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 02/17/2014] [Indexed: 11/19/2022] Open
Abstract
In contrast with the wealth of data involving bHLH and homeodomain transcription factors in retinal cell type determination, the molecular bases underlying neurotransmitter subtype specification is far less understood. Using both gain and loss of function analyses in Xenopus, we investigated the putative implication of the bHLH factor Ascl1 in this process. We found that in addition to its previously characterized proneural function, Ascl1 also contributes to the specification of the GABAergic phenotype. We showed that it is necessary for retinal GABAergic cell genesis and sufficient in overexpression experiments to bias a subset of retinal precursor cells towards a GABAergic fate. We also analysed the relationships between Ascl1 and a set of other bHLH factors using an in vivo ectopic neurogenic assay. We demonstrated that Ascl1 has unique features as a GABAergic inducer and is epistatic over factors endowed with glutamatergic potentialities such as Neurog2, NeuroD1 or Atoh7. This functional specificity is conferred by the basic DNA binding domain of Ascl1 and involves a specific genetic network, distinct from that underlying its previously demonstrated effects on catecholaminergic differentiation. Our data show that GABAergic inducing activity of Ascl1 requires the direct transcriptional regulation of Ptf1a, providing therefore a new piece of the network governing neurotransmitter subtype specification during retinogenesis.
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13
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Small molecules enable neurogenin 2 to efficiently convert human fibroblasts into cholinergic neurons. Nat Commun 2014; 4:2183. [PMID: 23873306 PMCID: PMC3843951 DOI: 10.1038/ncomms3183] [Citation(s) in RCA: 258] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 06/24/2013] [Indexed: 12/16/2022] Open
Abstract
Cell fate can be reprogrammed by modifying intrinsic and extrinsic cues. Here, we show that two small molecules (forskolin and dorsomorphin) enable the transcription factor Neurogenin 2 (NGN2) to convert human fetal lung fibroblasts into cholinergic neurons with high purity (>90%) and efficiency (up to 99% of NGN2-expressing cells). The conversion is direct without passing through a proliferative progenitor state. These human induced cholinergic neurons show mature electrophysiological properties and exhibit motor neuron-like features including morphology, gene expression, and the formation of functional neuromuscular junctions. Inclusion of an additional transcription factor, SOX11 also efficiently converts postnatal and adult skin fibroblasts from healthy and diseased human patients to cholinergic neurons. Taken together, this study identifies a simple and highly efficient strategy for reprogramming human fibroblasts to subtype-specific neurons. These findings offer a unique venue for investigating the molecular mechanisms underlying cellular plasticity and human neurodegenerative diseases.
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14
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Rhee YH, Choi M, Lee HS, Park CH, Kim SM, Yi SH, Oh SM, Cha HJ, Chang MY, Lee SH. Insulin concentration is critical in culturing human neural stem cells and neurons. Cell Death Dis 2013; 4:e766. [PMID: 23928705 PMCID: PMC3763456 DOI: 10.1038/cddis.2013.295] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 06/27/2013] [Accepted: 07/15/2013] [Indexed: 12/25/2022]
Abstract
Cell culture of human-derived neural stem cells (NSCs) is a useful tool that contributes to our understanding of human brain development and allows for the development of therapies for intractable human brain disorders. Human NSC (hNSC) cultures, however, are not commonly used, mainly because of difficulty with consistently maintaining the cells in a healthy state. In this study, we show that hNSC cultures, unlike NSCs of rodent origins, are extremely sensitive to insulin, an indispensable culture supplement, and that the previously reported difficulty in culturing hNSCs is likely because of a lack of understanding of this relationship. Like other neural cell cultures, insulin is required for hNSC growth, as withdrawal of insulin supplementation results in massive cell death and delayed cell growth. However, severe apoptotic cell death was also detected in insulin concentrations optimized to rodent NSC cultures. Thus, healthy hNSC cultures were only produced in a narrow range of relatively low insulin concentrations. Insulin-mediated cell death manifested not only in all human NSCs tested, regardless of origin, but also in differentiated human neurons. The underlying cell death mechanism at high insulin concentrations was similar to insulin resistance, where cells became less responsive to insulin, resulting in a reduction in the activation of the PI3K/Akt pathway critical to cell survival signaling.
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Affiliation(s)
- Y-H Rhee
- Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul, Korea
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15
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He XB, Yi SH, Rhee YH, Kim H, Han YM, Lee SH, Lee H, Park CH, Lee YS, Richardson E, Kim BW, Lee SH. Prolonged membrane depolarization enhances midbrain dopamine neuron differentiation via epigenetic histone modifications. Stem Cells 2012; 29:1861-73. [PMID: 21922608 DOI: 10.1002/stem.739] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Understanding midbrain dopamine (DA) neuron differentiation is of importance, because of physiological and clinical implications of this neuronal subtype. We show that prolonged membrane depolarization induced by KCl treatment promotes DA neuron differentiation from neural precursor cells (NPCs) derived from embryonic ventral midbrain (VM). Interestingly, the depolarization-induced increase of DA neuron yields was not abolished by L-type calcium channel blockers, along with no depolarization-mediated change of intracellular calcium level in the VM-derived NPCs (VM-NPCs), suggesting that the depolarization effect is due to a calcium-independent mechanism. Experiments with labeled DA neuron progenitors indicate that membrane depolarization acts at the differentiation fate determination stage and promotes the expression of DA phenotype genes (tyrosine hydroxylase [TH] and DA transporter [DAT]). Recruitment of Nurr1, a transcription factor crucial for midbrain DA neuron development, to the promoter of TH gene was enhanced by depolarization, along with increases of histone 3 acetylation (H3Ac) and trimethylation of histone3 on lysine 4 (H3K4m3), and decreases of H3K9m3 and H3K27m3 in the consensus Nurr1 binding regions of TH promoter. Depolarization stimuli on differentiating VM-NPCs also induced dissociation of methyl CpG binding protein 2 and related repressor complex molecules (repressor element-1 silencing transcription factor corepressor and histone deacetylase 1) from the CpG sites of TH and DAT promoters. Based on these findings, we suggest that membrane depolarization promotes DA neuron differentiation by opening chromatin structures surrounding DA phenotype genes and inhibiting the binding of corepressors, thus allowing transcriptional activators such as Nurr1 to access DA neuron differentiation gene promoter regions.
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Affiliation(s)
- Xi-Biao He
- Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul, Korea
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Messmer K, Shen WB, Remington M, Fishman PS. Induction of neural differentiation by the transcription factor neuroD2. Int J Dev Neurosci 2011; 30:105-12. [PMID: 22197973 DOI: 10.1016/j.ijdevneu.2011.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 09/30/2011] [Accepted: 12/09/2011] [Indexed: 01/08/2023] Open
Abstract
Pro-neural basic helix loop helix (bHLH) transcription factors are involved in many aspects of normal neuronal development, and over-expression of genes for several of these factors has been shown to induce aspects of neuronal differentiation in cell lines and stem cells. Here we show that over-expression of NeuroD2 (ND2), Neurogenin1 and 2 leads to morphological differentiation of N18-RE-105 neuroblastoma cells and increased expression of synaptic proteins. Particularly ND2 induced neurite formation and increases in the expression of synaptic proteins such as synaptotagmin, that is not expressed normally in this cell type, as well as the redistribution of another synaptic protein, SNAP25, to a cell membrane location. Infection of human neural progenitor cells using adeno associated viral (AAV) vectors also promoted neuronal differentiation. Over-expressing cells demonstrated a significant increase in the neuron specific form of tubulin as well as increased expression of synaptotagmin. Genetic modification of neural progenitor cell with bHLH factors such as ND2 may be a viable strategy to enhance differentiation of these cells into replacement neurons for human disease.
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Affiliation(s)
- Kirsten Messmer
- Department of Pharmacology and Experimental Therapeutics, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
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17
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Wogonin induces differentiation and neurite outgrowth of neural precursor cells. Biochem Biophys Res Commun 2010; 402:42-7. [DOI: 10.1016/j.bbrc.2010.09.098] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 09/24/2010] [Indexed: 01/04/2023]
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Peltopuro P, Kala K, Partanen J. Distinct requirements for Ascl1 in subpopulations of midbrain GABAergic neurons. Dev Biol 2010; 343:63-70. [PMID: 20417196 DOI: 10.1016/j.ydbio.2010.04.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 03/31/2010] [Accepted: 04/14/2010] [Indexed: 11/30/2022]
Abstract
Midbrain GABAergic neurons regulate multiple aspects of behavior and play important roles in psychiatric and neurological disease. These neurons constitute several anatomical and functional subpopulations, but their molecular heterogeneity and developmental regulatory mechanisms are poorly understood. Here we have studied the involvement of the proneural gene Ascl1 in the development of the midbrain GABAergic neurons. Analysis of Ascl1 mutant mice demonstrated highly region-specific requirements for Ascl1 for development of different GABAergic neuron subpopulations. Ascl1 is dispensable for the development of the ventral-most midbrain GABAergic neurons associated with dopaminergic nuclei substantia nigra pars reticulata (SNpr) and ventral tegmental area (VTA) GABAergic neurons. In the ventrolateral midbrain, loss of Ascl1 results in markedly delayed neurogenesis in the midbrain domains m3-m5. Within this region, Ascl1 has a unique role in m4, where it also regulates glutamatergic neurogenesis. Our results suggest that the m3-m5 midbrain neuroepithelium gives rise to the GABAergic neuron groups located in the midbrain reticular formation and ventrolateral periaqueductal gray. In contrast to m3-m5, Ascl1 is absolutely required in the dorsal midbrain domains m1-m2, for generation of the GABAergic neurons populating the superior and inferior colliculi as well as dorsal periaqueductal gray. These studies demonstrate different molecular regulatory mechanisms for the distinct midbrain GABAergic neuron subpopulations. Also, our results have implications on understanding the origins of the various midbrain GABAergic neuron groups in the embryonic neuroepithelium.
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Affiliation(s)
- Paula Peltopuro
- Institute of Biotechnology, P.O. Box 56, Viikinkaari 9, FIN00014-University of Helsinki, Helsinki, Finland
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19
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Ahmed S, Gan HT, Lam CS, Poonepalli A, Ramasamy S, Tay Y, Tham M, Yu YH. Transcription factors and neural stem cell self-renewal, growth and differentiation. Cell Adh Migr 2009; 3:412-24. [PMID: 19535895 DOI: 10.4161/cam.3.4.8803] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The central nervous system (CNS) is a large network of interconnecting and intercommunicating cells that form functional circuits. Disease and injury of the CNS are prominent features of the healthcare landscape. There is an urgent unmet need to generate therapeutic solutions for CNS disease/injury. To increase our understanding of the CNS we need to generate cellular models that are experimentally tractable. Neural stem cells (NSCs), cells that generate the CNS during embryonic development, have been identified and propagated in vitro. To develop NSCs as a cellular model for the CNS we need to understand more about their genetics and cell biology. In particular, we need to define the mechanisms of self-renewal, proliferation and differentiation--i.e. NSC behavior. The analysis of pluripotency of embryonic stem cells through mapping regulatory networks of transcription factors has proven to be a powerful approach to understanding embryonic development. Here, we discuss the role of transcription factors in NSC behavior.
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Affiliation(s)
- Sohail Ahmed
- Institute of Medical Biology, Immunos, Singapore.
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Selective induction of neocortical GABAergic neurons by the PDK1-Akt pathway through activation of Mash1. Proc Natl Acad Sci U S A 2009; 106:13064-9. [PMID: 19549840 DOI: 10.1073/pnas.0808400106] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Extracellular stimuli regulate neuronal differentiation and subtype specification during brain development, although the intracellular signaling pathways that mediate these processes remain largely unclear. We now show that the PDK1-Akt pathway regulates differentiation of telencephalic neural precursor cells (NPCs). Active Akt promotes differentiation of NPC into gamma-aminobutyric acid-containing (GABAergic) but not glutamatergic neurons. Disruption of the Pdk1 gene or expression of dominant-negative forms of Akt suppresses insulin-like growth factor (IGF)-1 enhancement of NPC differentiation into neurons in vitro and production of neocortical GABAergic neurons in vivo. Furthermore, active Akt increased the protein levels and transactivation activity of Mash1, a proneural basic helix-loop-helix protein required for the generation of neocortical GABAergic neurons, and Mash1 was required for Akt-induced neuronal differentiation. These results have unveiled an unexpected role of the PDK1-Akt pathway: a key mediator of extracellular signals regulating the production of neocortical GABAergic neurons.
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Bae EJ, Lee HS, Park CH, Lee SH. Orphan nuclear receptor Nurr1 induces neuron differentiation from embryonic cortical precursor cells via an extrinsic paracrine mechanism. FEBS Lett 2009; 583:1505-10. [PMID: 19362551 DOI: 10.1016/j.febslet.2009.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 03/30/2009] [Accepted: 04/07/2009] [Indexed: 10/20/2022]
Abstract
Nurr1 is an orphan nuclear receptor-type transcription factor (TF) that plays critical roles in midbrain dopamine neuron development. This study demonstrated a novel role for Nurr1 in neuronal/astrocytic differentiation of neural precursor (NP) cells isolated from rat embryonic cortices: overexpression of this TF promoted NP cell differentiation towards neurons at the expense of astrocytic differentiation. Single cell-based lineage analyses and experiments using co-cultures revealed that Nurr1 elicited its neurogenic role in an extrinsic paracrine manner. We defined diffusible factors and downstream neurogenic TFs responsible for the Nurr1-mediated neuronal differentiation.
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Affiliation(s)
- Eun-Ji Bae
- Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, # 17 Haengdang-dong, Sungdong-gu, Seoul 133-791, Republic of Korea
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Geoffroy CG, Critchley JA, Castro DS, Ramelli S, Barraclough C, Descombes P, Guillemot F, Raineteau O. Engineering of Dominant Active Basic Helix-Loop-Helix Proteins That Are Resistant to Negative Regulation by Postnatal Central Nervous System Antineurogenic Cues. Stem Cells 2009; 27:847-56. [DOI: 10.1002/stem.17] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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23
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Fähling M, Mrowka R, Steege A, Kirschner KM, Benko E, Förstera B, Persson PB, Thiele BJ, Meier JC, Scholz H. Translational regulation of the human achaete-scute homologue-1 by fragile X mental retardation protein. J Biol Chem 2008; 284:4255-66. [PMID: 19097999 DOI: 10.1074/jbc.m807354200] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fragile X syndrome is a common inherited cause of mental retardation that results from loss or mutation of the fragile X mental retardation protein (FMRP). In this study, we identified the mRNA of the basic helix-loop-helix transcription factor human achaete-scute homologue-1 (hASH1 or ASCL1), which is required for normal development of the nervous system and has been implicated in the formation of neuroendocrine tumors, as a new FMRP target. Using a double-immunofluorescent staining technique we detected an overlapping pattern of both proteins in the hippocampus, temporal cortex, subventricular zone, and cerebellum of newborn rats. Forced expression of FMRP and gene silencing by small interference RNA transfection revealed a positive correlation between the cellular protein levels of FMRP and hASH1. A luciferase reporter construct containing the 5'-untranslated region of hASH1 mRNA was activated by the full-length FMRP, but not by naturally occurring truncated FMR proteins, in transient co-transfections. The responsible cis-element was mapped by UV-cross-linking experiments and reporter mutagenesis assays to a (U)(10) sequence located in the 5'-untranslated region of the hASH1 mRNA. Sucrose density gradient centrifugation revealed that hASH1 transcripts were translocated into a translationally active polysomal fraction upon transient transfection of HEK293 cells with FMRP, thus indicating translational activation of hASH1 mRNA. In conclusion, we identified hASH1 as a novel downstream target of FMRP. Improved translation efficiency of hASH1 mRNA by FMRP may represent an important regulatory switch in neuronal differentiation.
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Affiliation(s)
- Michael Fähling
- Charité, Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Tucholskystrasse 2, D-10117 Berlin
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Park CH, Kang JS, Yoon EH, Shim JW, Suh-Kim H, Lee SH. Proneural bHLH neurogenin 2 differentially regulates Nurr1-induced dopamine neuron differentiation in rat and mouse neural precursor cells in vitro. FEBS Lett 2008; 582:537-42. [DOI: 10.1016/j.febslet.2008.01.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2007] [Revised: 12/13/2007] [Accepted: 01/08/2008] [Indexed: 11/28/2022]
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