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Dong W, Liu S, Li S, Wang Z. Cell reprogramming therapy for Parkinson's disease. Neural Regen Res 2024; 19:2444-2455. [PMID: 38526281 PMCID: PMC11090434 DOI: 10.4103/1673-5374.390965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/23/2023] [Accepted: 10/08/2023] [Indexed: 03/26/2024] Open
Abstract
Parkinson's disease is typically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Many studies have been performed based on the supplementation of lost dopaminergic neurons to treat Parkinson's disease. The initial strategy for cell replacement therapy used human fetal ventral midbrain and human embryonic stem cells to treat Parkinson's disease, which could substantially alleviate the symptoms of Parkinson's disease in clinical practice. However, ethical issues and tumor formation were limitations of its clinical application. Induced pluripotent stem cells can be acquired without sacrificing human embryos, which eliminates the huge ethical barriers of human stem cell therapy. Another widely considered neuronal regeneration strategy is to directly reprogram fibroblasts and astrocytes into neurons, without the need for intermediate proliferation states, thus avoiding issues of immune rejection and tumor formation. Both induced pluripotent stem cells and direct reprogramming of lineage cells have shown promising results in the treatment of Parkinson's disease. However, there are also ethical concerns and the risk of tumor formation that need to be addressed. This review highlights the current application status of cell reprogramming in the treatment of Parkinson's disease, focusing on the use of induced pluripotent stem cells in cell replacement therapy, including preclinical animal models and progress in clinical research. The review also discusses the advancements in direct reprogramming of lineage cells in the treatment of Parkinson's disease, as well as the controversy surrounding in vivo reprogramming. These findings suggest that cell reprogramming may hold great promise as a potential strategy for treating Parkinson's disease.
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Affiliation(s)
- Wenjing Dong
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan Province, China
| | - Shuyi Liu
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan Province, China
| | - Shangang Li
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan Province, China
| | - Zhengbo Wang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan Province, China
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2
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Li ST, Wan Y, Chen L, Ding Y. Advances in neuronal reprogramming for neurodegenerative diseases: Strategies, controversies, and opportunities. Exp Neurol 2024; 378:114817. [PMID: 38763354 DOI: 10.1016/j.expneurol.2024.114817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 05/21/2024]
Abstract
Neuronal death is often observed in central nervous system injuries and neurodegenerative diseases. The mammalian central nervous system manifests limited neuronal regeneration capabilities, and traditional cell therapies are limited in their potential applications due to finite cell sources and immune rejection. Neuronal reprogramming has emerged as a novel technology, in which non-neuronal cells (e.g. glial cells) are transdifferentiated into mature neurons. This process results in relatively minimal immune rejection. The present review discuss the latest progress in this cutting-edge field, including starter cell selection, innovative technical strategies and methods of neuronal reprogramming for neurodegenerative diseases, as well as the potential problems and controversies. The further development of neuronal reprogramming technology may pave the way for novel therapeutic strategies in the treatment of neurodegenerative diseases.
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Affiliation(s)
- Si-Tong Li
- Department of Histology and Embryology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Yue Wan
- Department of Histology and Embryology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Li Chen
- Department of Histology and Embryology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Yan Ding
- Department of Histology and Embryology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
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3
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Liu MH, Xu YG, Bai XN, Lin JH, Xiang ZQ, Wang T, Xu L, Chen G. Efficient Dlx2-mediated astrocyte-to-neuron conversion and inhibition of neuroinflammation by NeuroD1. Dev Neurobiol 2024. [PMID: 39034481 DOI: 10.1002/dneu.22951] [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: 08/21/2023] [Revised: 06/05/2024] [Accepted: 07/01/2024] [Indexed: 07/23/2024]
Abstract
In vivo astrocyte-to-neuron (AtN) conversion induced by overexpression of neural transcriptional factors has great potential for neural regeneration and repair. Here, we demonstrate that a single neural transcriptional factor, Dlx2, converts mouse striatal astrocytes into neurons in a dose-dependent manner. Lineage-tracing studies in Aldh1l1-CreERT2 mice confirm that Dlx2 can convert striatal astrocytes into DARPP32+ and Ctip2+ medium spiny neurons (MSNs). Time-course studies reveal a gradual conversion from astrocytes to neurons in 1 month, with a distinct intermediate state in between astrocytes and neurons. Interestingly, when Dlx2-infected astrocytes start to lose astrocytic markers, the other local astrocytes proliferate to maintain astrocytic levels in the converted areas. Unexpectedly, although Dlx2 efficiently reprograms astrocytes into neurons in the gray matter striatum, it also induces partial reprogramming of astrocytes in the white matter corpus callosum. Such partial reprogramming of white matter astrocytes is associated with neuroinflammation, which can be suppressed by the addition of NeuroD1. Our results highlight the importance of investigating AtN conversion in both the gray matter and white matter to thoroughly evaluate therapeutic potentials. This study also unveils the critical role of anti-inflammation by NeuroD1 during AtN conversion.
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Affiliation(s)
- Min-Hui Liu
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
- VIB Center for Brain and Disease, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Yu-Ge Xu
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
| | - Xiao-Ni Bai
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
| | - Jian-Hua Lin
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
| | - Zong-Qin Xiang
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
- Department of Neurosurgery, the First Affiliated Hospital, Jinan University, Guangzhou, Guangdong Province, China
| | - Tao Wang
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
| | - Liang Xu
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
| | - Gong Chen
- Guangdong-HongKong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
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Wu Y, Meng X, Cheng WY, Yan Z, Li K, Wang J, Jiang T, Zhou F, Wong KH, Zhong C, Dong Y, Gao S. Can pluripotent/multipotent stem cells reverse Parkinson's disease progression? Front Neurosci 2024; 18:1210447. [PMID: 38356648 PMCID: PMC10864507 DOI: 10.3389/fnins.2024.1210447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 01/02/2024] [Indexed: 02/16/2024] Open
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by continuous and selective degeneration or death of dopamine neurons in the midbrain, leading to dysfunction of the nigrostriatal neural circuits. Current clinical treatments for PD include drug treatment and surgery, which provide short-term relief of symptoms but are associated with many side effects and cannot reverse the progression of PD. Pluripotent/multipotent stem cells possess a self-renewal capacity and the potential to differentiate into dopaminergic neurons. Transplantation of pluripotent/multipotent stem cells or dopaminergic neurons derived from these cells is a promising strategy for the complete repair of damaged neural circuits in PD. This article reviews and summarizes the current preclinical/clinical treatments for PD, their efficacies, and the advantages/disadvantages of various stem cells, including pluripotent and multipotent stem cells, to provide a detailed overview of how these cells can be applied in the treatment of PD, as well as the challenges and bottlenecks that need to be overcome in future translational studies.
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Affiliation(s)
- Yongkang Wu
- Key Laboratory of Adolescent Health Evaluation and Sports Intervention, Ministry of Education, East China Normal University, Shanghai, China
| | - Xiangtian Meng
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Wai-Yin Cheng
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
- Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
| | - Zhichao Yan
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Keqin Li
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Jian Wang
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Tianfang Jiang
- Department of Neurology, Shanghai Eighth People’s Hospital Affiliated to Jiangsu University, Shanghai, China
| | - Fei Zhou
- Department of Neurology, Third Affiliated Hospital of Navy Military Medical University, Shanghai, China
| | - Ka-Hing Wong
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
- Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
| | - Chunlong Zhong
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yi Dong
- Key Laboratory of Adolescent Health Evaluation and Sports Intervention, Ministry of Education, East China Normal University, Shanghai, China
| | - Shane Gao
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
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Xiao H, Amarsaikhan O, Zhao Y, Yu X, Hu X, Han S, Chaolumen, Baigude H. Astrocyte-targeted siRNA delivery by adenosine-functionalized LNP in mouse TBI model. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 34:102065. [PMID: 38028196 PMCID: PMC10661454 DOI: 10.1016/j.omtn.2023.102065] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023]
Abstract
Traumatic brain injury (TBI) induces pro-inflammatory polarization of astrocytes and causes secondary disruption of the blood-brain barrier (BBB) and brain damage. Herein, we report a successful astrocyte-targeted delivery of small interfering RNA (siRNA) by ligand functionalized lipid nanoparticles (LNPs) formulated from adenosine-conjugated lipids and a novel ionizable lipid (denoted by Ad4 LNPs). Systemic administration of Ad4 LNPs carrying siRNA against TLR4 to the mice TBI model resulted in the specific internalization of the LNPs by astrocytes in the vicinity of damaged brain tissue. A substantial knockdown of TLR4 at both mRNA and protein levels in the brain was observed, which led to a significant decrease of key pro-inflammatory cytokines and an increase of key anti-inflammatory cytokines in serum. Dye leakage measurement suggested that the Ad4-LNP-mediated knockdown of TLR4 attenuated the TBI-induced BBB disruption. Together, our data suggest that Ad4 LNP is a promising vehicle for astrocyte-specific delivery of nucleic acid therapeutics.
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Affiliation(s)
- Hai Xiao
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
| | - Odmaa Amarsaikhan
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
| | - Yunwang Zhao
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
| | - Xiang Yu
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
| | - Xin Hu
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
| | - Shuqin Han
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
| | - Chaolumen
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
| | - Huricha Baigude
- Inner Mongolia Key Laboratory of Mongolian Medicinal Chemistry, School of Chemistry & Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010020, P.R. China
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Guo X, Jiang P, Pan M, Ding Y, Lin Y, Jiang T, Li R, Wang W, Dai Y, Wang S, Cao Y, Lin H, Yang M, Liu W, Tao J. Overexpression of miR-124 in astrocyte improves neurological deficits in rat with ischemic stroke via DLL4 modulation. Exp Neurol 2023; 370:114571. [PMID: 37848121 DOI: 10.1016/j.expneurol.2023.114571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/27/2023] [Accepted: 10/13/2023] [Indexed: 10/19/2023]
Abstract
BACKGROUND Astrocytes have been demonstrated to undergo conversion into functional neurons, presenting a promising approach for stroke treatment. However, the development of small molecules capable of effectively inducing this cellular reprogramming remains a critical challenge. METHODS Initially, we introduced a glial cell marker gene, GFaABC1D, as the promoter within an adeno-associated virus vector overexpressing miR-124 into the motor cortex of an ischemia-reperfusion model in rats. Additionally, we administered NeuroD1 as a positive control. Lentiviral vectors overexpressing miR-124 were constructed and transfected into primary rat astrocytes. We assessed the cellular distribution of GFAP, DCX, and NeuN on days 7, 14, and 28, respectively. RESULTS In rats with ischemic stroke, miR-124-transduced glial cells exhibited positive staining for the immature neuron marker doublecortin (DCX) and the mature neuron marker NeuN after 4 weeks. In contrast, NeuroD1-overexpressing model rats only expressed NeuN, and the positive percentage was higher in co-transfection with miR-124 and NeuroD1. Overexpression of miR-124 effectively ameliorated neurological deficits and motor functional impairment in the model rats. In primary rat astrocytes transduced with miR-124, DCX was not observed after 7 days of transfection, but it appeared at 14 days, with the percentage further increasing to 44.6% at 28 days. Simultaneously, 15.1% of miR-124-transduced cells exhibited NeuN positivity, which was not detected at 7 and 14 days. In vitro, double fluorescence assays revealed that miR-124 targeted Dll4, and in vivo experiments confirmed that miR-124 inhibited the expression of Notch1 and DLL4. CONCLUSIONS The overexpression of miR-124 in astrocytes demonstrates significant potential for improving neurological deficits following ischemic stroke by inhibiting DLL4 expression, and it may facilitate astrocyte-to-neuronal transformation.
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Affiliation(s)
- Xiaoqin Guo
- Provincial and Ministerial Co-founded Collaborative Innovation Center of Rehabilitation Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Pingli Jiang
- Provincial and Ministerial Co-founded Collaborative Innovation Center of Rehabilitation Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Meihua Pan
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Yanyi Ding
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Yanting Lin
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Tao Jiang
- Fujian Key Laboratory of Cognitive Rehabilitation, Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350001, China
| | - Rui Li
- Fujian Key Laboratory of Cognitive Rehabilitation, Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350001, China
| | - Wenju Wang
- Fujian Key Laboratory of Cognitive Rehabilitation, Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350001, China
| | - Yaling Dai
- Fujian Key Laboratory of Cognitive Rehabilitation, Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350001, China
| | - Sinuo Wang
- Traditional Chinese Medicine Rehabilitation Research Center of State Administration of Traditional Chinese Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Yajun Cao
- Traditional Chinese Medicine Rehabilitation Research Center of State Administration of Traditional Chinese Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Huawei Lin
- Traditional Chinese Medicine Rehabilitation Research Center of State Administration of Traditional Chinese Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Minguang Yang
- Traditional Chinese Medicine Rehabilitation Research Center of State Administration of Traditional Chinese Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Weilin Liu
- The Institute of Rehabilitation Industry, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China.
| | - Jing Tao
- The Institute of Rehabilitation Industry, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China.
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Yang G, Yan Z, Wu X, Zhang M, Xu C, Shi L, Yang H, Fang K. Ptbp1 knockdown failed to induce astrocytes to neurons in vivo. Gene Ther 2023; 30:801-806. [PMID: 36721028 DOI: 10.1038/s41434-023-00382-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 12/20/2022] [Accepted: 01/13/2023] [Indexed: 02/02/2023]
Abstract
The conversion of non-neuronal cells to neurons is a promising potential strategy for the treatment of neurodegenerative diseases. Recent studies have reported that shRNA-, CasRx-, or ASO-mediated Ptbp1 suppression could reprogram resident astrocytes to neurons. However, some groups have disputed the interpretation of the data underlying the reported neuron conversion events. These controversies surrounding neuron conversion may be due to differences in the astrocyte fate-mapping systems. Here, we suppressed Ptbp1 using Cas13X and labelled astrocytes with an HA tag fused to Cas13X (Cas13X-NLS-HA). We found no astrocyte-to-neuron conversion in the mouse striatum via the HA-tagged labelling system compared with the GFAP-driven tdTomato labelling system (AAV-GFAP::tdTomato-WPRE) used in previous studies. Our findings indicate that Cas13X-mediated Ptbp1 knockdown failed to induce neuron conversion in vivo.
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Affiliation(s)
| | - Zixiang Yan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | | | - Meng Zhang
- Huigene Therapeutics Inc., Shanghai, China
| | - Chunlong Xu
- Lingang Laboratory/Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai, China
| | - Linyu Shi
- Huigene Therapeutics Inc., Shanghai, China
| | - Hui Yang
- Huigene Therapeutics Inc., Shanghai, China.
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
| | - Kailun Fang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
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Woodworth MB, Greig LC, Goldberg JL. Intrinsic and Induced Neuronal Regeneration in the Mammalian Retina. Antioxid Redox Signal 2023; 39:1039-1052. [PMID: 37276181 PMCID: PMC10715439 DOI: 10.1089/ars.2023.0309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/05/2023] [Accepted: 05/14/2023] [Indexed: 06/07/2023]
Abstract
Significance: Retinal neurons are vulnerable to disease and injury, which can result in neuronal death and degeneration leading to irreversible vision loss. The human retina does not regenerate to replace neurons lost to disease or injury. However, cells within the retina of other animals are capable of regenerating neurons, and homologous cells within the mammalian retina could potentially be prompted to do the same. Activating evolutionarily silenced intrinsic regenerative capacity of the mammalian retina could slow, or even reverse, vision loss, leading to an improved quality of life for millions of people. Recent Advances: During development, neurons in the retina are generated progressively by retinal progenitor cells, with distinct neuron types born over developmental time. Many genes function in this process to specify the identity of newly generated neuron types, and these appropriate states of gene expression inform recent regenerative work. When regeneration is initiated in other vertebrates, including birds and fish, specific signaling pathways control the efficiency of regeneration, and these conserved pathways are likely to be important in mammals as well. Critical Issues: Using insights from development and from other animals, limited regeneration from intrinsic cell types has been demonstrated in the mammalian retina, but it is able only to generate a subset of partially differentiated retinal neuron types. Future Directions: Future studies should aim at increasing the efficiency of regeneration, activating regeneration in a targeted fashion across the retina, and improving the ability to generate specific types of retinal neurons to replace those lost to disease or injury. Antioxid. Redox Signal. 39, 1039-1052.
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Affiliation(s)
- Mollie B. Woodworth
- Department of Ophthalmology, Spencer Center for Vision Research, Byers Eye Institute, Stanford University, Palo Alto, California, USA
| | - Luciano C. Greig
- Department of Ophthalmology, Spencer Center for Vision Research, Byers Eye Institute, Stanford University, Palo Alto, California, USA
| | - Jeffrey L. Goldberg
- Department of Ophthalmology, Spencer Center for Vision Research, Byers Eye Institute, Stanford University, Palo Alto, California, USA
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9
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Gleichman AJ, Kawaguchi R, Sofroniew MV, Carmichael ST. A toolbox of astrocyte-specific, serotype-independent adeno-associated viral vectors using microRNA targeting sequences. Nat Commun 2023; 14:7426. [PMID: 37973910 PMCID: PMC10654773 DOI: 10.1038/s41467-023-42746-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 10/17/2023] [Indexed: 11/19/2023] Open
Abstract
Astrocytes, one of the most prevalent cell types in the central nervous system (CNS), are critically involved in neural function. Genetically manipulating astrocytes is an essential tool in understanding and affecting their roles. Adeno-associated viruses (AAVs) enable rapid genetic manipulation; however, astrocyte specificity of AAVs can be limited, with high off-target expression in neurons and sparsely in endothelial cells. Here, we report the development of a cassette of four copies of six miRNA targeting sequences (4x6T) which triggers transgene degradation specifically in neurons and endothelial cells. In combination with the GfaABC1D promoter, 4x6T increases astrocytic specificity of Cre with a viral reporter from <50% to >99% in multiple serotypes in mice, and confers astrocyte specificity in multiple recombinases and reporters. We also present empty vectors to add 4x6T to other cargo, independently and in Cre/Dre-dependent forms. This toolbox of AAVs allows rapid manipulation of astrocytes throughout the CNS, is compatible with different AAV serotypes, and demonstrates the efficacy of using multiplexed miRNA targeting sequences to decrease expression in multiple off-target cell populations simultaneously.
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Affiliation(s)
- Amy J Gleichman
- Department of Neurology, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, CA, USA
| | - Riki Kawaguchi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael V Sofroniew
- Department of Neurobiology, University of California-Los Angeles, Los Angeles, CA, USA
| | - S Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, CA, USA.
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10
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Wang LL, Zhang CL. Therapeutic Potential of PTBP1 Inhibition, If Any, Is Not Attributed to Glia-to-Neuron Conversion. Annu Rev Neurosci 2023; 46:1-15. [PMID: 36750409 PMCID: PMC10404630 DOI: 10.1146/annurev-neuro-092822-083410] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A holy grail of regenerative medicine is to replenish the cells that are lost due to disease. The adult mammalian central nervous system (CNS) has, however, largely lost such a regenerative ability. An emerging strategy for the generation of new neurons is through glia-to-neuron (GtN) conversion in vivo, mainly accomplished by the regulation of fate-determining factors. When inhibited, PTBP1, a factor involved in RNA biology, was reported to induce rapid and efficient GtN conversion in multiple regions of the adult CNS. Remarkably, PTBP1 inhibition was also claimed to greatly improve behaviors of mice with neurological diseases or aging. These phenomenal claims, if confirmed, would constitute a significant advancement in regenerative medicine. Unfortunately, neither GtN conversion nor therapeutic potential via PTBP1 inhibition was validated by the results of multiple subsequent replication studies with stringent methods. Here we review these controversial studies and conclude with recommendations for examining GtN conversion in vivo and future investigations of PTBP1.
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Affiliation(s)
- Lei-Lei Wang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
| | - Chun-Li Zhang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
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11
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Fu XD, Mobley WC. Therapeutic Potential of PTB Inhibition Through Converting Glial Cells to Neurons in the Brain. Annu Rev Neurosci 2023; 46:145-165. [PMID: 37428606 DOI: 10.1146/annurev-neuro-083022-113120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Cell replacement therapy represents a promising approach for treating neurodegenerative diseases. Contrary to the common addition strategy to generate new neurons from glia by overexpressing a lineage-specific transcription factor(s), a recent study introduced a subtraction strategy by depleting a single RNA-binding protein, Ptbp1, to convert astroglia to neurons not only in vitro but also in the brain. Given its simplicity, multiple groups have attempted to validate and extend this attractive approach but have met with difficulty in lineage tracing newly induced neurons from mature astrocytes, raising the possibility of neuronal leakage as an alternative explanation for apparent astrocyte-to-neuron conversion. This review focuses on the debate over this critical issue. Importantly, multiple lines of evidence suggest that Ptbp1 depletion can convert a selective subpopulation of glial cells into neurons and, via this and other mechanisms, reverse deficits in a Parkinson's disease model, emphasizing the importance of future efforts in exploring this therapeutic strategy.
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Affiliation(s)
- Xiang-Dong Fu
- Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China;
| | - William C Mobley
- Department of Neuroscience, University of California, San Diego, La Jolla, California, USA;
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12
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Stogsdill JA, Harwell CC, Goldman SA. Astrocytes as master modulators of neural networks: Synaptic functions and disease-associated dysfunction of astrocytes. Ann N Y Acad Sci 2023; 1525:41-60. [PMID: 37219367 DOI: 10.1111/nyas.15004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Astrocytes are the most abundant glial cell type in the central nervous system and are essential to the development, plasticity, and maintenance of neural circuits. Astrocytes are heterogeneous, with their diversity rooted in developmental programs modulated by the local brain environment. Astrocytes play integral roles in regulating and coordinating neural activity extending far beyond their metabolic support of neurons and other brain cell phenotypes. Both gray and white matter astrocytes occupy critical functional niches capable of modulating brain physiology on time scales slower than synaptic activity but faster than those adaptive responses requiring a structural change or adaptive myelination. Given their many associations and functional roles, it is not surprising that astrocytic dysfunction has been causally implicated in a broad set of neurodegenerative and neuropsychiatric disorders. In this review, we focus on recent discoveries concerning the contributions of astrocytes to the function of neural networks, with a dual focus on the contribution of astrocytes to synaptic development and maturation, and on their role in supporting myelin integrity, and hence conduction and its regulation. We then address the emerging roles of astrocytic dysfunction in disease pathogenesis and on potential strategies for targeting these cells for therapeutic purposes.
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Affiliation(s)
| | - Corey C Harwell
- Department of Neurology, University of California San Francisco, San Francisco, California, USA
| | - Steven A Goldman
- Sana Biotechnology Inc., Cambridge, Massachusetts, USA
- Center for Translational Neuromedicine, University of Rochester, Rochester, New York, USA
- University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
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13
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Develop an efficient and specific AAV-based labeling system for Muller glia in mice. Sci Rep 2022; 12:22410. [PMID: 36575359 PMCID: PMC9794687 DOI: 10.1038/s41598-022-27013-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Reprogramming Müller glia (MG) into functional cells is considered a promising therapeutic strategy to treat ocular diseases and vision loss. However, current AAV-based system for MG-tracing was reported to have high leakage in recent studies. Here, we focused on reducing the leakage of AAV-based labeling systems and found that different AAV serotypes showed a range of efficiency and specificity in labeling MG, leading us to optimize a human GFAP-Cre reporter system packaged in the AAV9 serotype with the woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) removed. The leakage ratio of the AAV9-hGFAP-Cre-ΔWPRE decreased by an approximate 40-fold compared with the AAV9-hGFAP-Cre-WPRE labeling system. In addition, we validated the specificity of the AAV-ΔWPRE system for tracing MG reprogramming under Ptbp1-suppression and observed strict non-MG-conversion, similar to previous studies using genetic lineage tracking mouse models. Thus, the AAV9-hGFAP-Cre-ΔWPRE system showed high efficiency and specificity for MG labeling, providing a promising tool for tracing cell fate in vivo.
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14
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Ghazale H, Park E, Vasan L, Mester J, Saleh F, Trevisiol A, Zinyk D, Chinchalongporn V, Liu M, Fleming T, Prokopchuk O, Klenin N, Kurrasch D, Faiz M, Stefanovic B, McLaurin J, Schuurmans C. Ascl1 phospho-site mutations enhance neuronal conversion of adult cortical astrocytes in vivo. Front Neurosci 2022; 16:917071. [PMID: 36061596 PMCID: PMC9434350 DOI: 10.3389/fnins.2022.917071] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Direct neuronal reprogramming, the process whereby a terminally differentiated cell is converted into an induced neuron without traversing a pluripotent state, has tremendous therapeutic potential for a host of neurodegenerative diseases. While there is strong evidence for astrocyte-to-neuron conversion in vitro, in vivo studies in the adult brain are less supportive or controversial. Here, we set out to enhance the efficacy of neuronal conversion of adult astrocytes in vivo by optimizing the neurogenic capacity of a driver transcription factor encoded by the proneural gene Ascl1. Specifically, we mutated six serine phospho-acceptor sites in Ascl1 to alanines (Ascl1SA6) to prevent phosphorylation by proline-directed serine/threonine kinases. Native Ascl1 or Ascl1SA6 were expressed in adult, murine cortical astrocytes under the control of a glial fibrillary acidic protein (GFAP) promoter using adeno-associated viruses (AAVs). When targeted to the cerebral cortex in vivo, mCherry+ cells transduced with AAV8-GFAP-Ascl1SA6-mCherry or AAV8-GFAP-Ascl1-mCherry expressed neuronal markers within 14 days post-transduction, with Ascl1SA6 promoting the formation of more mature dendritic arbors compared to Ascl1. However, mCherry expression disappeared by 2-months post-transduction of the AAV8-GFAP-mCherry control-vector. To circumvent reporter issues, AAV-GFAP-iCre (control) and AAV-GFAP-Ascl1 (or Ascl1SA6)-iCre constructs were generated and injected into the cerebral cortex of Rosa reporter mice. In all comparisons of AAV capsids (AAV5 and AAV8), GFAP promoters (long and short), and reporter mice (Rosa-zsGreen and Rosa-tdtomato), Ascl1SA6 transduced cells more frequently expressed early- (Dcx) and late- (NeuN) neuronal markers. Furthermore, Ascl1SA6 repressed the expression of astrocytic markers Sox9 and GFAP more efficiently than Ascl1. Finally, we co-transduced an AAV expressing ChR2-(H134R)-YFP, an optogenetic actuator. After channelrhodopsin photostimulation, we found that Ascl1SA6 co-transduced astrocytes exhibited a significantly faster decay of evoked potentials to baseline, a neuronal feature, when compared to iCre control cells. Taken together, our findings support an enhanced neuronal conversion efficiency of Ascl1SA6 vs. Ascl1, and position Ascl1SA6 as a critical transcription factor for future studies aimed at converting adult brain astrocytes to mature neurons to treat disease.
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Affiliation(s)
- Hussein Ghazale
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - EunJee Park
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Lakshmy Vasan
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - James Mester
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Fermisk Saleh
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Andrea Trevisiol
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Dawn Zinyk
- Sunnybrook Research Institute, Toronto, ON, Canada
| | - Vorapin Chinchalongporn
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Mingzhe Liu
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Taylor Fleming
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | | | - Natalia Klenin
- Department of Medical Genetics, Cumming School of Medicine, Hotchkiss Brain Institute, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Deborah Kurrasch
- Department of Medical Genetics, Cumming School of Medicine, Hotchkiss Brain Institute, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Maryam Faiz
- Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Bojana Stefanovic
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - JoAnne McLaurin
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- *Correspondence: Carol Schuurmans,
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15
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Ma NX, Puls B, Chen G. Transcriptomic analyses of NeuroD1-mediated astrocyte-to-neuron conversion. Dev Neurobiol 2022; 82:375-391. [PMID: 35606902 PMCID: PMC9540770 DOI: 10.1002/dneu.22882] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 05/03/2022] [Accepted: 05/05/2022] [Indexed: 12/30/2022]
Abstract
Ectopic expression of a single neural transcription factor NeuroD1 can reprogram reactive glial cells into functional neurons both in vitro and in vivo, but the underlying mechanisms are not well understood yet. Here, we used RNA-sequencing technology to capture the transcriptomic changes at different time points during the reprogramming process. We found that following NeuroD1 overexpression, astroglial genes (ACTG1, ALDH1A3, EMP1, CLDN6, SOX21) were significantly downregulated, whereas neuronal genes (DCX, RBFOX3/NeuN, CUX2, RELN, SNAP25) were significantly upregulated. NeuroD family members (NeuroD1/2/6) and signaling pathways (Wnt, MAPK, cAMP) as well as neurotransmitter receptors (acetylcholine, somatostatin, dopamine) were also significantly upregulated. Gene co-expression analysis identified many central genes among the NeuroD1-interacting network, including CABP7, KIAA1456, SSTR2, GADD45G, LRRTM2, and INSM1. Compared to chemical conversion, we found that NeuroD1 acted as a strong driving force and triggered fast transcriptomic changes during astrocyte-to-neuron conversion process. Together, this study reveals many important downstream targets of NeuroD1 such as HES6, BHLHE22, INSM1, CHRNA1/3, CABP7, and SSTR2, which may play critical roles during the transcriptomic landscape shift from a glial profile to a neuronal profile.
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Affiliation(s)
- Ning-Xin Ma
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Brendan Puls
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Gong Chen
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA.,GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
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16
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Chen W, Zheng Q, Huang Q, Ma S, Li M. Repressing PTBP1 fails to convert reactive astrocytes to dopaminergic neurons in a 6-hydroxydopamine mouse model of Parkinson's disease. eLife 2022; 11:75636. [PMID: 35535997 PMCID: PMC9208759 DOI: 10.7554/elife.75636] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 05/06/2022] [Indexed: 11/16/2022] Open
Abstract
Lineage reprogramming of resident glial cells to dopaminergic neurons (DAns) is an attractive prospect of the cell-replacement therapy for Parkinson’s disease (PD). However, it is unclear whether repressing polypyrimidine tract binding protein 1 (PTBP1) could efficiently convert astrocyte to DAns in the substantia nigra and striatum. Although reporter-positive DAns were observed in both groups after delivering the adeno-associated virus (AAV) expressing a reporter with shRNA or CRISPR-CasRx to repress astroglial PTBP1, the possibility of AAV leaking into endogenous DAns could not be excluded without using a reliable lineage-tracing method. By adopting stringent lineage-tracing strategy, two other studies show that either knockdown or genetic deletion of quiescent astroglial PTBP1 fails to obtain induced DAns under physiological condition. However, the role of reactive astrocytes might be underestimated because upon brain injury, reactive astrocyte can acquire certain stem cell hallmarks that may facilitate the lineage conversion process. Therefore, whether reactive astrocytes could be genuinely converted to DAns after PTBP1 repression in a PD model needs further validation. In this study, we used Aldh1l1-CreERT2-mediated specific astrocyte-lineage-tracing method to investigate whether reactive astrocytes could be converted to DAns in a 6-hydroxydopamine (6-OHDA) mouse model of PD. However, we found that no astrocyte-originated DAn was generated after effective and persistent knockdown of astroglial PTBP1 either in the substantia nigra or in striatum, while AAV ‘leakage’ to nearby neurons was easily observed. Our results confirm that repressing PTBP1 does not convert astrocytes to DAns, regardless of physiological or PD-related pathological conditions.
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Affiliation(s)
- Weizhao Chen
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Qiongping Zheng
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Qiaoying Huang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Shanshan Ma
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Mingtao Li
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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17
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Wang LL, Zhang CL. In vivo glia-to-neuron conversion: pitfalls and solutions. Dev Neurobiol 2022; 82:367-374. [PMID: 35535734 DOI: 10.1002/dneu.22880] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/15/2022] [Accepted: 05/05/2022] [Indexed: 11/08/2022]
Abstract
Neuron loss and disruption of neural circuits are associated with many neurological conditions. A key question is how to rebuild neural circuits for functional improvements. In vivo glia-to-neuron (GtN) conversion emerges as a potential solution for regeneration-based therapeutics. This approach takes advantage of the regenerative ability of resident glial cells to produce new neurons through cell fate reprogramming. Significant progress has been made over the years in this emerging field. However, inappropriate analysis often leads to misleading conclusions that create confusion and hype. In this perspective, we point out the most salient pitfalls associated with some recent studies and provide solutions to prevent them in the future. The goal is to foster healthy development of this promising field and lay a solid cellular foundation for future regeneration-based medicine. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Lei-Lei Wang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Chun-Li Zhang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
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