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Yang X, Zhou B. Unleashing metabolic power for axonal regeneration. Trends Endocrinol Metab 2024:S1043-2760(24)00182-6. [PMID: 39069446 DOI: 10.1016/j.tem.2024.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/13/2024] [Accepted: 07/03/2024] [Indexed: 07/30/2024]
Abstract
Axon regeneration requires the mobilization of intracellular resources, including proteins, lipids, and nucleotides. After injury, neurons need to adapt their metabolism to meet the biosynthetic demands needed to achieve axonal regeneration. However, the exact contribution of cellular metabolism to this process remains elusive. Insights into the metabolic characteristics of proliferative cells may illuminate similar mechanisms operating in axon regeneration; therefore, unraveling previously unappreciated roles of metabolic adaptation is critical to achieving neuron regrowth, which is connected to the therapeutic strategies for neurological conditions necessitating nerve repairs, such as spinal cord injury and stroke. Here, we outline the metabolic role in axon regeneration and discuss factors enhancing nerve regrowth, highlighting potential novel metabolic treatments for restoring nerve function.
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Affiliation(s)
- Xiaoyan Yang
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing 100191, China
| | - Bing Zhou
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing 100191, China; School of Engineering Medicine, Beihang University, Beijing 100191, China.
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2
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Luo W, Egger M, Cruz-Ochoa N, Tse A, Maloveczky G, Tamás B, Lukacsovich D, Seng C, Amrein I, Lukacsovich T, Wolfer D, Földy C. Activation of feedforward wiring in adult hippocampal neurons by the basic-helix-loop-helix transcription factor Ascl4. PNAS NEXUS 2024; 3:pgae174. [PMID: 38711810 PMCID: PMC11071515 DOI: 10.1093/pnasnexus/pgae174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/17/2024] [Indexed: 05/08/2024]
Abstract
Although evidence indicates that the adult brain retains a considerable capacity for circuit formation, adult wiring has not been broadly considered and remains poorly understood. In this study, we investigate wiring activation in adult neurons. We show that the basic-helix-loop-helix transcription factor Ascl4 can induce wiring in different types of hippocampal neurons of adult mice. The new axons are mainly feedforward and reconfigure synaptic weights in the circuit. Mice with the Ascl4-induced circuits do not display signs of pathology and solve spatial problems equally well as controls. Our results demonstrate reprogrammed connectivity by a single transcriptional factor and provide insights into the regulation of brain wiring in adults.
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Affiliation(s)
- Wenshu Luo
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
| | - Matteo Egger
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
- Adaptive Brain Circuits in Development and Learning (AdaBD), University Research Priority Program (URPP), University of Zürich, Zürich 8057, Switzerland
| | - Natalia Cruz-Ochoa
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
- Adaptive Brain Circuits in Development and Learning (AdaBD), University Research Priority Program (URPP), University of Zürich, Zürich 8057, Switzerland
| | - Alice Tse
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
| | - Gyula Maloveczky
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
| | - Bálint Tamás
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
| | - David Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
| | - Charlotte Seng
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
| | - Irmgard Amrein
- Institute of Anatomy, Faculty of Medicine, University of Zürich, Zürich 8057, Switzerland
| | - Tamás Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
| | - David Wolfer
- Institute of Anatomy, Faculty of Medicine, University of Zürich, Zürich 8057, Switzerland
- Institute of Human Movement Sciences and Sport, D-HEST, ETH Zürich, Zürich 8057, Switzerland
| | - Csaba Földy
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich 8057, Switzerland
- Adaptive Brain Circuits in Development and Learning (AdaBD), University Research Priority Program (URPP), University of Zürich, Zürich 8057, Switzerland
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Duan Q, Zheng H, Qin Y, Yan J, Wang J, Burgess SM, Fan C. Stat3 Has a Different Role in Axon Growth During Development Than It Does in Axon Regeneration After Injury. Mol Neurobiol 2024; 61:1753-1768. [PMID: 37775721 DOI: 10.1007/s12035-023-03644-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: 04/27/2023] [Accepted: 09/07/2023] [Indexed: 10/01/2023]
Abstract
Signal transducer and activator of transcription 3 (STAT3) is essential for neural development and regeneration as a key transcription factor and mitochondrial activator. However, the mechanism of Stat3 in axon development and regeneration has not been fully understood. In this study, using zebrafish posterior lateral line (PLL) axons, we demonstrate that Stat3 plays distinct roles in PLL axon embryonic growth and regeneration. Our experiments indicate that stat3 is required for PLL axon extension. In stat3 mutant zebrafish, the PLL axon ends were stalled at the level of the cloaca, and expression of stat3 rescues the PLL axon growth in a cell-autonomous manner. Jak/Stat signaling inhibition did not affect PLL axon growth indicating Jak/Stat was dispensable for PLL axon growth. In addition, we found that Stat3 was co-localized with mitochondria in PLL axons and important for the mitochondrial membrane potential and ATPase activity. The PLL axon growth defect of stat3 mutants was mimicked and rescued by rotenone and DCHC treatment, respectively, which suggests that Stat3 regulates PLL axon growth through mitochondrial Stat3. By contrast, mutation of stat3 or Jak/Stat signaling inhibition retarded PLL axon regeneration. Meanwhile, we also found Schwann cell migration was also inhibited in stat3 mutants. Taken together, Stat3 is required for embryonic PLL axon growth by regulating the ATP synthesis efficiency of mitochondria, whereas Stat3 stimulates PLL axon regeneration by regulating Schwann cell migration via Jak/Stat signaling. Our findings show a new mechanism of Stat3 in axon growth and regeneration.
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Affiliation(s)
- Qinwen Duan
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Hongfei Zheng
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yanjun Qin
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Jizhou Yan
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Jian Wang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Shawn M Burgess
- Translational and Functional Genomics Branch, National Human Genome Research Institute, Bethesda, MD, USA
| | - Chunxin Fan
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China.
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China.
- Marine Biomedical Science and Technology Innovation Platform of Lingang New Area, Shanghai, China.
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4
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Lukomska A, Theune WC, Frost MP, Xing J, Kearney A, Trakhtenberg EF. Upregulation of developmentally-downregulated miR-1247-5p promotes neuroprotection and axon regeneration in vivo. Neurosci Lett 2024; 823:137662. [PMID: 38286398 PMCID: PMC10923146 DOI: 10.1016/j.neulet.2024.137662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 01/31/2024]
Abstract
Numerous micro-RNAs (miRNAs) affect neurodevelopment and neuroprotection, but potential roles of many miRNAs in regulating these processes are still unknown. Here, we used the retinal ganglion cell (RGC) central nervous system (CNS) projection neuron and optic nerve crush (ONC) injury model, to optimize a mature miRNA arm-specific quantification method for characterizing the developmental regulation of miR-1247-5p in RGCs, investigated whether injury affects its expression, and tested whether upregulating miR-1247-5p-mimic in RGCs promotes neuroprotection and axon regeneration. We found that, miR-1247-5p is developmentally-downregulated in RGCs, and is further downregulated after ONC. Importantly, RGC-specific upregulation of miR-1247-5p promoted neuroprotection and axon regeneration after injury in vivo. To gain insight into the underlying mechanisms, we analyzed by bulk-mRNA-seq embryonic and adult RGCs, along with adult RGCs transduced by miR-1247-5p-expressing viral vector, and identified developmentally-regulated cilial and mitochondrial biological processes, which were reinstated to their embryonic levels in adult RGCs by upregulation of miR-1247-5p. Since axon growth is also a developmentally-regulated process, in which mitochondrial dynamics play important roles, it is possible that miR-1247-5p promoted neuroprotection and axon regeneration through regulating mitochondrial functions.
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Affiliation(s)
- Agnieszka Lukomska
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - William C Theune
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Matthew P Frost
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Jian Xing
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Anja Kearney
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA.
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5
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Smit RD, Ghosh B, Campion TJ, Stingel R, Lavell E, Hooper R, Fan X, Soboloff J, Smith GM. STAT3 protects dopaminergic neurons against degeneration in animal model of Parkinson's disease. Brain Res 2024; 1824:148691. [PMID: 38030102 PMCID: PMC10842767 DOI: 10.1016/j.brainres.2023.148691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 11/22/2023] [Accepted: 11/26/2023] [Indexed: 12/01/2023]
Abstract
INTRODUCTION Parkinson's disease (PD) is the most prevalent disorder of the basal ganglia, propagated by the degeneration of axon terminals within the striatum and subsequent loss of dopaminergic neurons in the substantia nigra (SN). Exposure of environmental neurotoxins and mutations of several mitochondrial and proteasomal genes are primarily responsible. METHODS To determine whether signal transducer and activator of transcription 3 (STAT3) could protect dopaminergic neurons against degeneration, we first screened it in the in vitro capacity using immortalized rat dopaminergic N27 cells under 6-OHDA neurotoxicity. We then evaluated the effectiveness of constitutively active (ca) STAT3 as a neuroprotective agent on N27 cells in a 6-hydroxydopamine (6-OHDA) induced rat model of PD and compared it to control animals or animals where AAV/caRheb was expressed in SN. Behavioral outcomes were assessed using rotational and cylinder assays and mitochondrial function using reactive oxygen species (ROS) levels. RESULTS Using flow cytometry, the in vitro analysis determined caSTAT3 significantly decreased dopaminergic neuronal death under 6-OHDA treatment conditions. Importantly, in vivo overexpression of caSTAT3 in SN dopaminergic neurons using AAV-mediated expression demonstrated significant neuroprotection of dopaminergic neurons following 6-OHDA. Both caSTAT3 and caRheb + caSTAT3 co-injection into substantia nigra reduced D-amphetamine-induced rotational behavior and increased ipsilateral forelimb function when compared to control animals. In addition, caSTAT3 decreased mitochondrial ROS production following 6-OHDA induced neurotoxicity. CONCLUSION caSTAT3 confers resistance against ROS production in mitochondria of susceptible SN dopaminergic neurons potentially offering a new avenue for treatment against PD.
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Affiliation(s)
- Rupert D Smit
- Department of Neuroscience & Shriners Hospitals for Pediatric Research Center, Temple University, USA.
| | - Biswarup Ghosh
- Department of Neuroscience & Shriners Hospitals for Pediatric Research Center, Temple University, USA
| | - Thomas J Campion
- Department of Neuroscience & Shriners Hospitals for Pediatric Research Center, Temple University, USA
| | - Rachel Stingel
- Department of Neuroscience & Shriners Hospitals for Pediatric Research Center, Temple University, USA
| | - Emily Lavell
- Department of Neuroscience & Shriners Hospitals for Pediatric Research Center, Temple University, USA
| | - Robert Hooper
- Fels Institute for Cancer Research & Molecular Biology, Temple University, USA
| | - Xiaoxuan Fan
- Flow Cytometry Core Facility, Temple University, USA
| | - Jonathan Soboloff
- Fels Institute for Cancer Research & Molecular Biology, Temple University, USA
| | - George M Smith
- Department of Neuroscience & Shriners Hospitals for Pediatric Research Center, Temple University, USA
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6
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Gu M, Li X, Wu R, Cheng X, Zhou S, Gu X. The Transcription Factor Ets1 Influences Axonal Growth via Regulation of Lcn2. Mol Neurobiol 2024; 61:971-981. [PMID: 37672148 PMCID: PMC10861751 DOI: 10.1007/s12035-023-03616-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 08/25/2023] [Indexed: 09/07/2023]
Abstract
Transcription factors are essential for the development and regeneration of the nervous system. The current study investigated key regulatory transcription factors in rat spinal cord development via RNA sequencing. The hub gene Ets1 was highly expressed in the spinal cord during the embryonic period, and then its expression decreased during spinal cord development. Knockdown of Ets1 significantly increased the axonal growth of cultured spinal cord neurons. Luciferase reporter assays and chromatin immunoprecipitation assays indicated that Ets1 could directly bind to the Lcn2 promoter and positively regulate Lcn2 transcription. In conclusion, these findings provide the first direct evidence that Ets1 regulates axon growth by controlling Lcn2 expression, and Ets1 may be a novel therapeutic target for axon regeneration in the central nervous system.
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Affiliation(s)
- Miao Gu
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
- School of Basic Medical Sciences, Hebei Key Laboratory of Nerve Injury and Repair, Chengde Medical University, Chengde, Hebei, China
| | - Xiaodi Li
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Ronghua Wu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu, China
| | - Xiao Cheng
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu, China
| | - Songlin Zhou
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu, China.
| | - Xiaosong Gu
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China.
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu, China.
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7
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Richardson PJ, Smith DP, de Giorgio A, Snetkov X, Almond-Thynne J, Cronin S, Mead RJ, McDermott CJ, Shaw PJ. Janus kinase inhibitors are potential therapeutics for amyotrophic lateral sclerosis. Transl Neurodegener 2023; 12:47. [PMID: 37828541 PMCID: PMC10568794 DOI: 10.1186/s40035-023-00380-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/03/2023] [Indexed: 10/14/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a poorly treated multifactorial neurodegenerative disease associated with multiple cell types and subcellular organelles. As with other multifactorial diseases, it is likely that drugs will need to target multiple disease processes and cell types to be effective. We review here the role of Janus kinase (JAK)/Signal transducer and activator of transcription (STAT) signalling in ALS, confirm the association of this signalling with fundamental ALS disease processes using the BenevolentAI Knowledge Graph, and demonstrate that inhibitors of this pathway could reduce the ALS pathophysiology in neurons, glia, muscle fibres, and blood cells. Specifically, we suggest that inhibition of the JAK enzymes by approved inhibitors known as Jakinibs could reduce STAT3 activation and modify the progress of this disease. Analysis of the Jakinibs highlights baricitinib as a suitable candidate due to its ability to penetrate the central nervous system and exert beneficial effects on the immune system. Therefore, we recommend that this drug be tested in appropriately designed clinical trials for ALS.
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Affiliation(s)
| | | | | | | | | | - Sara Cronin
- BenevolentAI, 15 MetroTech Centre, 8th FL, Brooklyn, NY, 11201, USA
| | - Richard J Mead
- Sheffield Institute for Translational Neuroscience, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, UK
| | - Christopher J McDermott
- Sheffield Institute for Translational Neuroscience, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, UK
- NIHR Sheffield Biomedical Research Centre, University of Sheffield and Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, UK
- NIHR Sheffield Biomedical Research Centre, University of Sheffield and Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
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8
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Ávila-Mendoza J, Delgado-Rueda K, Urban-Sosa VA, Carranza M, Luna M, Martínez-Moreno CG, Arámburo C. KLF13 Regulates the Activity of the GH-Induced JAK/STAT Signaling by Targeting Genes Involved in the Pathway. Int J Mol Sci 2023; 24:11187. [PMID: 37446365 DOI: 10.3390/ijms241311187] [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: 06/15/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
The Krüppel-like factor 13 (KLF13) has emerged as an important transcription factor involved in essential processes of the central nervous system (CNS). It predominantly functions as a transcriptional repressor, impacting the activity of several signaling pathways with essential roles in the CNS, including the JAK/STAT pathway, which is the canonical mediator of growth hormone (GH) signaling. It is now recognized that GH has important actions as a neurotrophic factor. Therefore, we analyzed the effects of KLF13 on the activity of the JAK/STAT signaling pathway in the hippocampus-derived cell line HT22. Results showed that KLF13 directly regulates the expression of several genes involved in the JAK-STAT pathway, including Jak1, Jak2, Jak3, and Socs1, by associating with their proximal gene promoters. In addition, it was found that in KLF13-deficient HT22 neurons, the expression of Jak1, Stat3, Socs1, Socs3, and Igf1 was dysregulated, exhibiting mRNA levels that went up to 7-fold higher than the control cell line. KLF13 displayed a differential effect on the GH-induced JAK/STAT pathway activity, decreasing the STAT3 branch while enhancing the STAT5 branch. In KLF13-deficient HT22 cells, the activity of the STAT3 branch was enhanced, mediating the GH-dependent augmented expression of the JAK/STAT output genes Socs1, Socs3, Igf1, and Bdnf. Furthermore, GH treatment increased both the nuclear content of KLF13 and Klf13 mRNA levels, suggesting that KLF13 could be part of the mechanisms that maintain the homeostatic state of this pathway. These findings support the notion that KLF13 is a regulator of JAK/STAT activity.
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Affiliation(s)
- José Ávila-Mendoza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico
| | - Karen Delgado-Rueda
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico
| | - Valeria A Urban-Sosa
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico
| | - Martha Carranza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico
| | - Maricela Luna
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico
| | - Carlos G Martínez-Moreno
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico
| | - Carlos Arámburo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico
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9
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Zhang ZY, Zuo ZY, Liang Y, Zhang SM, Zhang CX, Chi J, Fan B, Li GY. Promotion of axon regeneration and protection on injured retinal ganglion cells by rCXCL2. Inflamm Regen 2023; 43:31. [PMID: 37340465 DOI: 10.1186/s41232-023-00283-5] [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: 11/21/2022] [Accepted: 05/31/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND In addition to rescuing injured retinal ganglion cells (RGCs) by stimulating the intrinsic growth ability of damaged RGCs in various retinal/optic neuropathies, increasing evidence has shown that the external microenvironmental factors also play a crucial role in restoring the survival of RGCs by promoting the regrowth of RGC axons, especially inflammatory factors. In this study, we aimed to screen out the underlying inflammatory factor involved in the signaling of staurosporine (STS)-induced axon regeneration and verify its role in the protection of RGCs and the promotion of axon regrowth. METHODS We performed transcriptome RNA sequencing for STS induction models in vitro and analyzed the differentially expressed genes. After targeting the key gene, we verified the role of the candidate factor in RGC protection and promotion of axon regeneration in vivo with two RGC-injured animal models (optic nerve crush, ONC; retinal N-methyl-D-aspartate, NMDA damage) by using cholera toxin subunit B anterograde axon tracing and specific immunostaining of RGCs. RESULTS We found that a series of inflammatory genes expressed upregulated in the signaling of STS-induced axon regrowth and we targeted the candidate CXCL2 gene since the level of the chemokine CXCL2 gene elevated significantly among the top upregulated genes. We further demonstrated that intravitreal injection of rCXCL2 robustly promoted axon regeneration and significantly improved RGC survival in ONC-injured mice in vivo. However, different from its role in ONC model, the intravitreal injection of rCXCL2 was able to simply protect RGCs against NMDA-induced excitotoxicity in mouse retina and maintain the long-distance projection of RGC axons, yet failed to promote significant axon regeneration. CONCLUSIONS We provide the first in vivo evidence that CXCL2, as an inflammatory factor, is a key regulator in the axon regeneration and neuroprotection of RGCs. Our comparative study may facilitate deciphering the exact molecular mechanisms of RGC axon regeneration and developing high-potency targeted drugs.
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Affiliation(s)
- Zi-Yuan Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Zhao-Yang Zuo
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Yang Liang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Si-Ming Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Chun-Xia Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Jing Chi
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Bin Fan
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China.
| | - Guang-Yu Li
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China.
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10
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Clary RC, Jenkins BA, Lumpkin EA. Spatiotemporal dynamics of sensory neuron and Merkel-cell remodeling are decoupled during epidermal homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528558. [PMID: 36824872 PMCID: PMC9949164 DOI: 10.1101/2023.02.14.528558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
As the juncture between the body and environment, epithelia are both protective barriers and sensory interfaces that continually renew. To determine whether sensory neurons remodel to maintain homeostasis, we used in vivo two-photon imaging of somatosensory axons innervating Merkel cells in adult mouse skin. These touch receptors were highly plastic: 63% of Merkel cells and 89% of branches appeared, disappeared, grew, regressed and/or relocated over a month. Interestingly, Merkel-cell plasticity was synchronized across arbors during rapid epithelial turnover. When Merkel cells remodeled, the degree of plasticity between Merkel-cell clusters and their axons was well correlated. Moreover, branches were stabilized by Merkel-cell contacts. These findings highlight the role of epithelial-neural crosstalk in homeostatic remodeling. Conversely, axons were also dynamic when Merkel cells were stable, indicating that intrinsic neural mechanisms drive branch plasticity. Two terminal morphologies innervated Merkel cells: transient swellings called boutons, and stable cups termed kylikes. In Atoh1 knockout mice that lack Merkel cells, axons showed higher complexity than control mice, with exuberant branching and no kylikes. Thus, Merkel cells limit axonal branching and promote branch maturation. Together, these results reveal a previously unsuspected high degree of plasticity in somatosensory axons that is biased, but not solely dictated, by plasticity of target epithelial cells. This system provides a platform to identify intrinsic and extrinsic mechanisms that govern axonal patterning in epithelial homeostasis.
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11
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Barron A, Manna S, McElwain CJ, Musumeci A, McCarthy FP, O’Keeffe GW, McCarthy CM. Maternal pre-eclampsia serum increases neurite growth and mitochondrial function through a potential IL-6-dependent mechanism in differentiated SH-SY5Y cells. Front Physiol 2023; 13:1043481. [PMID: 36714304 PMCID: PMC9877349 DOI: 10.3389/fphys.2022.1043481] [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: 09/13/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Abstract
Introduction: Pre-eclampsia (PE) is a common and serious hypertensive disorder of pregnancy, which affects 3%-5% of first-time pregnancies and is a leading cause of maternal and neonatal morbidity and mortality. Prenatal exposure to PE is associated with an increased risk of neurodevelopmental disorders in affected offspring, although the cellular and molecular basis of this increased risk is largely unknown. Methods: Here, we examined the effects of exposure to maternal serum from women with PE or a healthy uncomplicated pregnancy on the survival, neurite growth and mitochondrial function of neuronally differentiated human SH-SY5Y neuroblastoma cells, which are commonly used to study neurite growth. Neurite growth and mitochondrial function are two strongly linked neurodevelopmental parameters in which alterations have been implicated in neurodevelopmental disorders. Following this, we investigated the pleiotropic cytokine interleukin-6 (IL-6) levels as a potential mechanism. Results: Cells exposed to 3% (v/v) PE serum for 72 h exhibited increased neurite growth (p < 0.05), which was validated in the human neural progenitor cell line, ReNcell® VM (p < 0.01), and mitochondrial respiration (elevated oxygen consumption rate (p < 0.05), basal mitochondrial respiration, proton leak, ATP synthesis, and non-mitochondrial respiration) compared to control serum-treated cells. ELISA analysis showed elevations in maternal IL-6 in PE sera (p < 0.05) and placental explants (p < 0.05). In support of this, SH-SY5Y cells exposed to 3% (v/v) PE serum for 24 h had increased phospho-STAT3 levels, which is a key intracellular mediator of IL-6 signalling (p < 0.05). Furthermore, treatment with anti-IL-6 neutralizing antibody blocked the effects of PE serum on neurite growth (p < 0.05), and exposure to IL-6 promoted neurite growth in SH-SY5Y cells (p < 0.01). Discussion: Collectively these data show elevated serum levels of maternal IL-6 in PE, which increases neurite growth and mitochondrial function in SH-SY5Y cells. This rationalizes the further study of IL-6 as a potential mediator between PE exposure and neurodevelopmental outcome in the offspring.
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Affiliation(s)
- Aaron Barron
- Department of Anatomy and Neuroscience, University College, Cork, Ireland,Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland
| | - Samprikta Manna
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland,Department of Obstetrics and Gynaecology, Cork University Maternity Hospital, Cork, Ireland
| | - Colm J. McElwain
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland
| | - Andrea Musumeci
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland
| | - Fergus P. McCarthy
- Department of Obstetrics and Gynaecology, Cork University Maternity Hospital, Cork, Ireland
| | - Gerard W. O’Keeffe
- Department of Anatomy and Neuroscience, University College, Cork, Ireland,Cork Neuroscience Centre, University College Cork, Cork, Ireland,*Correspondence: Gerard W. O’Keeffe, ; Cathal M. McCarthy,
| | - Cathal M. McCarthy
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland,*Correspondence: Gerard W. O’Keeffe, ; Cathal M. McCarthy,
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12
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Yu W, Ren C, Ji X. A review of remote ischemic conditioning as a potential strategy for neural repair poststroke. CNS Neurosci Ther 2022; 29:516-524. [PMID: 36550592 PMCID: PMC9873528 DOI: 10.1111/cns.14064] [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: 06/24/2022] [Revised: 11/17/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Ischemic stroke is one of the major disabling health-care problem and multiple different approaches are needed to enhance rehabilitation, in which neural repair is the structural basement. Remote ischemic conditioning (RIC) is a strategy to trigger endogenous protect. RIC has been reported to play neuroprotective role in acute stage of stroke, but the effect of RIC on repair process remaining unclear. Several studies have discovered some overlapped mechanisms RIC and neural repair performs. This review provides a hypothesis that RIC is a potential therapeutic strategy on stroke rehabilitation by evaluating the existing evidence and puts forward some remaining questions to clarify and future researches to be performed in the field.
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Affiliation(s)
- Wantong Yu
- Department of Neurology and Beijing Key Laboratory of Hypoxia Translational MedicineXuanwu Hospital, Capital Medical UniversityBeijingChina
| | - Changhong Ren
- Department of Neurology and Beijing Key Laboratory of Hypoxia Translational MedicineXuanwu Hospital, Capital Medical UniversityBeijingChina,Center of Stroke, Beijing Institute for Brain DisorderCapital Medical UniversityBeijingChina
| | - Xunming Ji
- Department of Neurology and Beijing Key Laboratory of Hypoxia Translational MedicineXuanwu Hospital, Capital Medical UniversityBeijingChina,Center of Stroke, Beijing Institute for Brain DisorderCapital Medical UniversityBeijingChina
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13
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GADD34 Ablation Exacerbates Retinal Degeneration in P23H RHO Mice. Int J Mol Sci 2022; 23:ijms232213748. [PMID: 36430227 PMCID: PMC9697375 DOI: 10.3390/ijms232213748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
The UPR is sustainably activated in degenerating retinas, leading to translational inhibition via p-eIF2α. Recent findings have demonstrated that ablation of growth arrest and DNA damage-inducible protein 34 (GADD34), a protein phosphatase 1 regulatory subunit permitting translational machinery operation through p-eIF2α elevation, does not impact the rate of translation in fast-degenerating rd16 mice. The current study aimed to validate whether P23H RHO mice degenerating at a slower pace manifest translational attenuation and whether GADD34 ablation impacts the rate of retinal degeneration via further suppression of retinal protein synthesis and apoptotic cell death. For this study, mice were examined with ERG and histological analyses. The molecular assessment was conducted in the naïve and LPS-challenged mice using Western blot and qRT-PCR analyses. Thus, this study demonstrates that the P23H RHO retinas manifest translational attenuation. However, GADD34 ablation resulted in a more prominent p-eIF2a increase without impacting the translation rate. GADD34 deficiency also led to a reduction in scotopic ERG amplitudes and an increased number of TUNEL-positive cells. Molecular analysis revealed that GADD34 deficiency reduces the expression of p-STAT3 and Il-6 while increasing the expression of Tnfa. Overall, the data indicate that GADD34 plays a multifunctional role. Under chronic UPR activation, GADD34 acts as a feedback player, dephosphorylating p-eIF2a, although this role does not seem to be critical. Additionally, GADD34 controls cytokine expression and STAT3 activation. Perhaps these molecular events are particularly important in controlling the pace of retinal degeneration.
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14
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Transcriptional Control of Peripheral Nerve Regeneration. Mol Neurobiol 2022; 60:329-341. [PMID: 36261692 DOI: 10.1007/s12035-022-03090-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/10/2022] [Indexed: 10/24/2022]
Abstract
Transcription factors are master regulators of various cellular processes under diverse physiological and pathological conditions. Many transcription factors that are differentially expressed after injury to peripheral nerves play important roles in nerve regeneration. Considering that rapid and timely regrowth of injured axons is a prerequisite for successful target reinnervation, here, we compile transcription factors that mediates axon elongation, including axon growth suppressor Klf4 and axon growth promoters c-Myc, Sox11, STAT3, Atf3, c-Jun, Smad1, C/EBPδ, and p53. Besides neuronal changes, Schwann cell phenotype modulation is also critical for nerve regeneration. The activation of Schwann cells at early time points post injury provides a permissive microenvironment whereas the re-differentiation of Schwann cells at later time points supports myelin sheath formation. Hence, c-Jun and Sox2, two critical drivers for Schwann cell reprogramming, as well as Krox-20 and Sox10, two essential regulators of Schwann cell myelination, are reviewed. These transcription factors may serve as promising targets for promoting the functional recovery of injured peripheral nerves.
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15
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Noro T, Shah SH, Yin Y, Kawaguchi R, Yokota S, Chang KC, Madaan A, Sun C, Coppola G, Geschwind D, Benowitz LI, Goldberg JL. Elk-1 regulates retinal ganglion cell axon regeneration after injury. Sci Rep 2022; 12:17446. [PMID: 36261683 PMCID: PMC9581912 DOI: 10.1038/s41598-022-21767-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 09/30/2022] [Indexed: 01/12/2023] Open
Abstract
Adult central nervous system (CNS) axons fail to regenerate after injury, and master regulators of the regenerative program remain to be identified. We analyzed the transcriptomes of retinal ganglion cells (RGCs) at 1 and 5 days after optic nerve injury with and without a cocktail of strongly pro-regenerative factors to discover genes that regulate survival and regeneration. We used advanced bioinformatic analysis to identify the top transcriptional regulators of upstream genes and cross-referenced these with the regulators upstream of genes differentially expressed between embryonic RGCs that exhibit robust axon growth vs. postnatal RGCs where this potential has been lost. We established the transcriptional activator Elk-1 as the top regulator of RGC gene expression associated with axon outgrowth in both models. We demonstrate that Elk-1 is necessary and sufficient to promote RGC neuroprotection and regeneration in vivo, and is enhanced by manipulating specific phosphorylation sites. Finally, we co-manipulated Elk-1, PTEN, and REST, another transcription factor discovered in our analysis, and found Elk-1 to be downstream of PTEN and inhibited by REST in the survival and axon regenerative pathway in RGCs. These results uncover the basic mechanisms of regulation of survival and axon growth and reveal a novel, potent therapeutic strategy to promote neuroprotection and regeneration in the adult CNS.
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Affiliation(s)
- Takahiko Noro
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
- Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan
| | - Sahil H Shah
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA.
- Medical Scientist Training Program, University of California San Diego, La Jolla, CA, USA.
| | - Yuqin Yin
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Riki Kawaguchi
- Departments of Neurology and Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Satoshi Yokota
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
- Kobe City Eye Hospital, Kobe, Hyogo, Japan
| | - Kun-Che Chang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ankush Madaan
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
| | - Catalina Sun
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
| | - Giovanni Coppola
- Departments of Neurology and Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Daniel Geschwind
- Departments of Neurology and Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Larry I Benowitz
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
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Wong KA, Benowitz LI. Retinal Ganglion Cell Survival and Axon Regeneration after Optic Nerve Injury: Role of Inflammation and Other Factors. Int J Mol Sci 2022; 23:ijms231710179. [PMID: 36077577 PMCID: PMC9456227 DOI: 10.3390/ijms231710179] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/24/2022] Open
Abstract
The optic nerve, like most pathways in the mature central nervous system, cannot regenerate if injured, and within days, retinal ganglion cells (RGCs), the neurons that extend axons through the optic nerve, begin to die. Thus, there are few clinical options to improve vision after traumatic or ischemic optic nerve injury or in neurodegenerative diseases such as glaucoma, dominant optic neuropathy, or optic pathway gliomas. Research over the past two decades has identified several strategies to enable RGCs to regenerate axons the entire length of the optic nerve, in some cases leading to modest reinnervation of di- and mesencephalic visual relay centers. This review primarily focuses on the role of the innate immune system in improving RGC survival and axon regeneration, and its synergy with manipulations of signal transduction pathways, transcription factors, and cell-extrinsic suppressors of axon growth. Research in this field provides hope that clinically effective strategies to improve vision in patients with currently untreatable losses could become a reality in 5-10 years.
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Affiliation(s)
- Kimberly A. Wong
- Department of Neurosurgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Correspondence: (K.A.W.); (L.I.B.)
| | - Larry I. Benowitz
- Department of Neurosurgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
- Correspondence: (K.A.W.); (L.I.B.)
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17
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Ribeiro M, Ayupe AC, Beckedorff FC, Levay K, Rodriguez S, Tsoulfas P, Lee JK, Nascimento-Dos-Santos G, Park KK. Retinal ganglion cell expression of cytokine enhances occupancy of NG2 cell-derived astrocytes at the nerve injury site: Implication for axon regeneration. Exp Neurol 2022; 355:114147. [PMID: 35738417 PMCID: PMC10648309 DOI: 10.1016/j.expneurol.2022.114147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 05/27/2022] [Accepted: 06/14/2022] [Indexed: 11/18/2022]
Abstract
Following injury in the central nervous system, a population of astrocytes occupy the lesion site, form glial bridges and facilitate axon regeneration. These astrocytes originate primarily from resident astrocytes or NG2+ oligodendrocyte progenitor cells. However, the extent to which these cell types give rise to the lesion-filling astrocytes, and whether the astrocytes derived from different cell types contribute similarly to optic nerve regeneration remain unclear. Here we examine the distribution of astrocytes and NG2+ cells in an optic nerve crush model. We show that optic nerve astrocytes partially fill the injury site over time after a crush injury. Viral mediated expression of a growth-promoting factor, ciliary neurotrophic factor (CNTF), in retinal ganglion cells (RGCs) promotes axon regeneration without altering the lesion size or the degree of lesion-filling GFAP+ cells. Strikingly, using inducible NG2CreER driver mice, we found that CNTF overexpression in RGCs increases the occupancy of NG2+ cell-derived astrocytes in the optic nerve lesion. An EdU pulse-chase experiment shows that the increase in NG2 cell-derived astrocytes is not due to an increase in cell proliferation. Lastly, we performed RNA-sequencing on the injured optic nerve and reveal that CNTF overexpression in RGCs results in significant changes in the expression of distinct genes, including those that encode chemokines, growth factor receptors, and immune cell modulators. Even though CNTF-induced axon regeneration has long been recognized, this is the first evidence of this procedure affecting glial cell fate at the optic nerve crush site. We discuss possible implication of these results for axon regeneration.
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Affiliation(s)
- Marcio Ribeiro
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA; Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, AA7103 MCN/VUIIS, 1161 21st Ave. S., Nashville, TN 37232, USA
| | - Ana C Ayupe
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Felipe C Beckedorff
- Sylvester Comprehensive Cancer Center, Department of Human Genetics, Biomedical Research Building, University of Miami Miller School of Medicine, Room 715, 1501 NW 10th Avenue, Miami, FL 33136, USA
| | - Konstantin Levay
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Sara Rodriguez
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Pantelis Tsoulfas
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Jae K Lee
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Gabriel Nascimento-Dos-Santos
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Kevin K Park
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA.
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18
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Tapia ML, Nascimento-dos-Santos G, Park KK. Subtype-specific survival and regeneration of retinal ganglion cells in response to injury. Front Cell Dev Biol 2022; 10:956279. [PMID: 36035999 PMCID: PMC9411869 DOI: 10.3389/fcell.2022.956279] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 06/28/2022] [Indexed: 11/19/2022] Open
Abstract
Retinal ganglion cells (RGCs) are a heterogeneous population of neurons that function synchronously to convey visual information through the optic nerve to retinorecipient target areas in the brain. Injury or disease to the optic nerve results in RGC degeneration and loss of visual function, as few RGCs survive, and even fewer can be provoked to regenerate their axons. Despite causative insults being broadly shared, regeneration studies demonstrate that RGC types exhibit differential resilience to injury and undergo selective survival and regeneration of their axons. While most early studies have identified these RGC types based their morphological and physiological characteristics, recent advances in transgenic and gene sequencing technologies have further enabled type identification based on unique molecular features. In this review, we provide an overview of the well characterized RGC types and identify those shown to preferentially survive and regenerate in various regeneration models. Furthermore, we discuss cellular characteristics of both the resilient and susceptible RGC types including the combinatorial expression of different molecular markers that identify these specific populations. Lastly, we discuss potential molecular mechanisms and genes found to be selectively expressed by specific types that may contribute to their reparative capacity. Together, we describe the studies that lay the important groundwork for identifying factors that promote neural regeneration and help advance the development of targeted therapy for the treatment of RGC degeneration as well as neurodegenerative diseases in general.
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19
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Histological and molecular characterization of glaucoma model induced by one or two injections of microbeads to the anterior chamber of mice. Int Ophthalmol 2022; 42:3763-3775. [PMID: 35731354 DOI: 10.1007/s10792-022-02372-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 05/28/2022] [Indexed: 10/17/2022]
Abstract
PURPOSE To characterize glaucoma-induced damage following injections of plastic microbeads into the anterior chamber of mice. METHODS Mice were divided into three groups: a single plastic microbeads injection (n = 21); two consecutive plastic microbead injections to the right eye at 1-week intervals, 4 of which with two consecutive saline injections in the left eye (n = 15); and an additional control group of two consecutive saline injections at 1-week intervals (n = 6). Intraocular pressure (IOP) was measured weekly. Retinal thickness, ganglion cells (RGCs) and axonal loss, inflammatory and gliosis reactions were measured at week four. Molecular analysis using qRT-PCR in the microbeads injection groups focused on expression levels of inflammation and glaucoma-related genes. RESULTS Mean IOP following single injection at 4 weeks was significantly elevated compared to baseline in injected eyes (14.5 ± 3.3 mmHg vs. 11.1 ± 2.5 mmHg, respectively, p = 0.003) and not in fellow eyes (13.2 ± 2.9 mmHg vs. 12.2 ± 2.9, respectively, NS). Six (35.3%) bead-injected eyes had IOP ≥ 17 mmHg compared with 2 (11.8%) saline-injected control eyes. Retinal thickness in injected and fellow eyes was 193.7 ± 15.5 µm and 223.9 ± 15.5 µm, respectively (p = 0.03). RGC loss in injected and fellow eyes was 16.0 ± 0.5 and 17.6 ± 0.7 cells per 200 µm, respectively (p = 0.005). Retinal gliosis, axonal loss and inflammatory cell infiltration to the bead-injected eyes were noted. Molecular analysis following double injection showed STAT3 expression decreased in the glaucoma-induced optic nerves (0.69 ± 0.3 vs. 1.16 ± 0.3, p = 0.04), but increased in the glaucoma-induced retinae (p = 0.05) versus saline; retinal IL-1β decreased significantly (0.04 ± 0.04 vs. 0.36 ± 0.2, p = 0.02). TNF-α, NFkB and SOD-1 expression did not change. CONCLUSION One/two injections of microbeads elevated IOP, with measurable neuronal damage. An inflammatory response was detected in the injured retina and optic nerve. The therapeutic significance of these findings should be explored.
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20
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Li S, Zhou H, Xie M, Zhang Z, Gou J, Yang J, Tian C, Ma K, Wang CY, Lu Y, Li Q, Peng W, Xiang M. Regenerating islet-derived protein 3 gamma (Reg3g) ameliorates tacrolimus-induced pancreatic β-cell dysfunction in mice by restoring mitochondrial function. Br J Pharmacol 2022; 179:3078-3095. [PMID: 35060126 DOI: 10.1111/bph.15803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Tacrolimus a first-line medication used after transplantation can induce β-cell dysfunction, causing new-onset diabetes mellitus (NODM). Regenerating islet-derived protein 3 gamma (Reg3g), a member of the pancreatic regenerative gene family, has been reported to improve type 1 diabetes by promoting β-cell regeneration. We aim to investigate the role of Reg3g in reversing tacrolimus-induced β-cell dysfunction and NODM in mice. EXPERIMENTAL APPROACH Circulating REG3A (the human homologue of mouse Reg3g) in heart transplantation patients treated with tacrolimus was detected. The glucose-stimulated insulin secretion and mitochondrial functions, including mitochondria membrane potential (MMP), mitochondria calcium, ATP production, oxygen consumption rate and mitochondrial morphology were investigated in β-cells. Additionally, effects of Reg3g on tacrolimus-induced NODM in mice were analysed. KEY RESULTS Circulating REG3A level in heart transplantation patients with NODM significantly decreased compared with those without diabetes. Tacrolimus down-regulated Reg3g via inhibiting STAT3-mediated transcription activation. Moreover, Reg3g restored glucose-stimulated insulin secretion suppressed by tacrolimus in β-cells by improving mitochondrial functions, including increased MMP, mitochondria calcium uptake, ATP production, oxygen consumption rate and contributing to an intact mitochondrial morphology. Mechanistically, Reg3g increased accumulation of pSTAT3(Ser727) in mitochondria by activating ERK1/2-STAT3 signalling pathway, leading to restoration of tacrolimus-induced mitochondrial impairment. Reg3g overexpression also effectively mitigated tacrolimus-induced NODM in mice. CONCLUSION AND IMPLICATIONS Reg3g can significantly ameliorate tacrolimus-induced β-cell dysfunction by restoring mitochondrial function in a pSTAT3(Ser727)-dependent manner. Our observations identify a novel Reg3g-mediated mechanism that is involved in tacrolimus-induced NODM and establish the novel role of Reg3g in reversing tacrolimus-induced β-cell dysfunction.
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Affiliation(s)
- Senlin Li
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong Zhou
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Mengyuan Xie
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zijun Zhang
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Gou
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian Yang
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cheng Tian
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kun Ma
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cong-Yi Wang
- The Center for Biomedical Research, Department of Respiratory and Critical Care Medicine, NHC Key Laboratory of Respiratory Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Sciences and Technology, Wuhan, China
| | - Yi Lu
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Li
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wen Peng
- Department of General Practice, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ming Xiang
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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21
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Chen S, Lathrop KL, Kuwajima T, Gross JM. Retinal ganglion cell survival after severe optic nerve injury is modulated by crosstalk between Jak/Stat signaling and innate immune responses in the zebrafish retina. Development 2022; 149:272198. [PMID: 34528064 DOI: 10.1242/dev.199694] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/23/2021] [Indexed: 12/15/2022]
Abstract
Visual information is transmitted from the eye to the brain along the optic nerve, a structure composed of retinal ganglion cell (RGC) axons. The optic nerve is highly vulnerable to damage in neurodegenerative diseases, such as glaucoma, and there are currently no FDA-approved drugs or therapies to protect RGCs from death. Zebrafish possess remarkable neuroprotective and regenerative abilities. Here, utilizing an optic nerve transection (ONT) injury and an RNA-seq-based approach, we identify genes and pathways active in RGCs that may modulate their survival. Through pharmacological perturbation, we demonstrate that Jak/Stat pathway activity is required for RGC survival after ONT. Furthermore, we show that immune responses directly contribute to RGC death after ONT; macrophages/microglia are recruited to the retina and blocking neuroinflammation or depleting these cells after ONT rescues survival of RGCs. Taken together, these data support a model in which crosstalk between macrophages/microglia and RGCs, mediated by Jak/Stat pathway activity, regulates RGC survival after optic nerve injury.
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Affiliation(s)
- Si Chen
- Eye Center of Xiangya Hospital, Central South University, 410008 Changsha, Hunan, People's Republic of China.,Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Hunan Key Laboratory of Ophthalmology, 410008 Changsha, Hunan, People's Republic of China
| | - Kira L Lathrop
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania, United States of America
| | - Takaaki Kuwajima
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Department of Developmental Biology, Louis J. Fox Center for Vision Restoration, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jeffrey M Gross
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Department of Developmental Biology, Louis J. Fox Center for Vision Restoration, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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Regulation of mitochondrial morphology and metabolism by Jak-STAT pathway. JOURNAL OF ANIMAL REPRODUCTION AND BIOTECHNOLOGY 2021. [DOI: 10.12750/jarb.36.4.189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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23
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Correia JC, Kelahmetoglu Y, Jannig PR, Schweingruber C, Shvaikovskaya D, Zhengye L, Cervenka I, Khan N, Stec M, Oliveira M, Nijssen J, Martínez-Redondo V, Ducommun S, Azzolini M, Lanner JT, Kleiner S, Hedlund E, Ruas JL. Muscle-secreted neurturin couples myofiber oxidative metabolism and slow motor neuron identity. Cell Metab 2021; 33:2215-2230.e8. [PMID: 34592133 DOI: 10.1016/j.cmet.2021.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 05/28/2021] [Accepted: 09/07/2021] [Indexed: 01/04/2023]
Abstract
Endurance exercise promotes skeletal muscle vascularization, oxidative metabolism, fiber-type switching, and neuromuscular junction integrity. Importantly, the metabolic and contractile properties of the muscle fiber must be coupled to the identity of the innervating motor neuron (MN). Here, we show that muscle-derived neurturin (NRTN) acts on muscle fibers and MNs to couple their characteristics. Using a muscle-specific NRTN transgenic mouse (HSA-NRTN) and RNA sequencing of MN somas, we observed that retrograde NRTN signaling promotes a shift toward a slow MN identity. In muscle, NRTN increased capillary density and oxidative capacity and induced a transcriptional reprograming favoring fatty acid metabolism over glycolysis. This combination of effects on muscle and MNs makes HSA-NRTN mice lean with remarkable exercise performance and motor coordination. Interestingly, HSA-NRTN mice largely recapitulate the phenotype of mice with muscle-specific expression of its upstream regulator PGC-1ɑ1. This work identifies NRTN as a myokine that couples muscle oxidative capacity to slow MN identity.
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Affiliation(s)
- Jorge C Correia
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Yildiz Kelahmetoglu
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Paulo R Jannig
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Christoph Schweingruber
- Department of Neuroscience, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden; Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Dasha Shvaikovskaya
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Liu Zhengye
- Molecular Muscle Physiology and Pathophysiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Igor Cervenka
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Naveen Khan
- Regeneron Pharmaceuticals, Tarrytown, NY 10 591, USA
| | - Michael Stec
- Regeneron Pharmaceuticals, Tarrytown, NY 10 591, USA
| | - Mariana Oliveira
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Jik Nijssen
- Department of Neuroscience, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Vicente Martínez-Redondo
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Serge Ducommun
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Michele Azzolini
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Johanna T Lanner
- Molecular Muscle Physiology and Pathophysiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden
| | | | - Eva Hedlund
- Department of Neuroscience, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden; Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Jorge L Ruas
- Molecular and Cellular Exercise Physiology, Department of Physiology and Pharmacology, Biomedicum, Karolinska Institutet, 17165 Stockholm, Sweden.
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Recurrent rewiring of the adult hippocampal mossy fiber system by a single transcriptional regulator, Id2. Proc Natl Acad Sci U S A 2021; 118:2108239118. [PMID: 34599103 PMCID: PMC8501755 DOI: 10.1073/pnas.2108239118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2021] [Indexed: 12/03/2022] Open
Abstract
Neurons have an exceptional capacity to grow axons and form synaptic circuits during development but not later life. In adults, the lack of circuit formation may support retention of skilled actions and memories but also limits regeneration and repair after injuries and in disorders. Research on developing and damaged neurons has revealed many molecules that help circuit formation and regeneration, and yet factors that could induce axon growth and synapse formation in adult brain neurons remain elusive. Here, we searched for such key molecules and find one that alone can induce complete circuit formation. After engineering a new circuit in adult mice, we also looked into its function and relevance for memories. Circuit formation in the central nervous system has been historically studied during development, after which cell-autonomous and nonautonomous wiring factors inactivate. In principle, balanced reactivation of such factors could enable further wiring in adults, but their relative contributions may be circuit dependent and are largely unknown. Here, we investigated hippocampal mossy fiber sprouting to gain insight into wiring mechanisms in mature circuits. We found that sole ectopic expression of Id2 in granule cells is capable of driving mossy fiber sprouting in healthy adult mouse and rat. Mice with the new mossy fiber circuit solved spatial problems equally well as controls but appeared to rely on local rather than global spatial cues. Our results demonstrate reprogrammed connectivity in mature neurons by one defined factor and an assembly of a new synaptic circuit in adult brain.
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Ketogenesis controls mitochondrial gene expression and rescues mitochondrial bioenergetics after cervical spinal cord injury in rats. Sci Rep 2021; 11:16359. [PMID: 34381166 PMCID: PMC8357839 DOI: 10.1038/s41598-021-96003-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 07/29/2021] [Indexed: 11/08/2022] Open
Abstract
A better understanding of the secondary injury mechanisms that occur after traumatic spinal cord injury (SCI) is essential for the development of novel neuroprotective strategies linked to the restoration of metabolic deficits. We and others have shown that Ketogenic diet (KD), a high fat, moderate in proteins and low in carbohydrates is neuroprotective and improves behavioural outcomes in rats with acute SCI. Ketones are alternative fuels for mitochondrial ATP generation, and can modulate signaling pathways via targeting specific receptors. Here, we demonstrate that ad libitum administration of KD for 7 days after SCI rescued mitochondrial respiratory capacity, increased parameters of mitochondrial biogenesis, affected the regulation of mitochondrial-related genes, and activated the NRF2-dependent antioxidant pathway. This study demonstrates that KD improves post-SCI metabolism by rescuing mitochondrial function and supports the potential of KD for treatment of acute SCI in humans.
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Chemokine CCL5 promotes robust optic nerve regeneration and mediates many of the effects of CNTF gene therapy. Proc Natl Acad Sci U S A 2021; 118:2017282118. [PMID: 33627402 DOI: 10.1073/pnas.2017282118] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Ciliary neurotrophic factor (CNTF) is a leading therapeutic candidate for several ocular diseases and induces optic nerve regeneration in animal models. Paradoxically, however, although CNTF gene therapy promotes extensive regeneration, recombinant CNTF (rCNTF) has little effect. Because intraocular viral vectors induce inflammation, and because CNTF is an immune modulator, we investigated whether CNTF gene therapy acts indirectly through other immune mediators. The beneficial effects of CNTF gene therapy remained unchanged after deleting CNTF receptor alpha (CNTFRα) in retinal ganglion cells (RGCs), the projection neurons of the retina, but were diminished by depleting neutrophils or by genetically suppressing monocyte infiltration. CNTF gene therapy increased expression of C-C motif chemokine ligand 5 (CCL5) in immune cells and retinal glia, and recombinant CCL5 induced extensive axon regeneration. Conversely, CRISPR-mediated knockdown of the cognate receptor (CCR5) in RGCs or treating wild-type mice with a CCR5 antagonist repressed the effects of CNTF gene therapy. Thus, CCL5 is a previously unrecognized, potent activator of optic nerve regeneration and mediates many of the effects of CNTF gene therapy.
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Fague L, Liu YA, Marsh-Armstrong N. The basic science of optic nerve regeneration. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1276. [PMID: 34532413 PMCID: PMC8421956 DOI: 10.21037/atm-20-5351] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 01/15/2021] [Indexed: 12/25/2022]
Abstract
Diverse insults to the optic nerve result in partial to total vision loss as the axons of retinal ganglion cells are destroyed. In glaucoma, axons are injured at the optic nerve head; in other optic neuropathies, axons can be damaged along the entire visual pathway. In all cases, as mammals cannot regenerate injured central nervous system cells, once the axons are lost, vision loss is irreversible. However, much has been learned about how retinal ganglion cells respond to axon injuries, and many of these crucial discoveries offer hope for future regenerative therapies. Here we review the current understanding regarding the temporal progression of axonal degeneration. We summarize known survival and regenerative mechanisms in mammals, including specific signaling pathways, key transcription factors, and reprogramming genes. We cover mechanisms intrinsic to retinal ganglion cells as well as their interactions with myeloid and glial cell populations in the retina and optic nerve that affect survival and regeneration. Finally, we highlight some non-mammalian species that are able to regenerate their retinal ganglion cell axons after injury, as understanding these successful regenerative responses may be essential to the rational design of future clinical interventions to regrow the optic nerve. In the end, a combination of many different molecular and cellular interventions will likely be the only way to achieve functional recovery of vision and restore quality of life to millions of patients around the world.
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Affiliation(s)
- Lindsay Fague
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Yin Allison Liu
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Nicholas Marsh-Armstrong
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
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Pita-Thomas W, Gonçalves TM, Kumar A, Zhao G, Cavalli V. Genome-wide chromatin accessibility analyses provide a map for enhancing optic nerve regeneration. Sci Rep 2021; 11:14924. [PMID: 34290335 PMCID: PMC8295311 DOI: 10.1038/s41598-021-94341-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 07/05/2021] [Indexed: 11/21/2022] Open
Abstract
Retinal Ganglion Cells (RGCs) lose their ability to grow axons during development. Adult RGCs thus fail to regenerate their axons after injury, leading to vision loss. To uncover mechanisms that promote regeneration of RGC axons, we identified transcription factors (TF) and open chromatin regions that are enriched in rat embryonic RGCs (high axon growth capacity) compared to postnatal RGCs (low axon growth capacity). We found that developmental stage-specific gene expression changes correlated with changes in promoter chromatin accessibility. Binding motifs for TFs such as CREB, CTCF, JUN and YY1 were enriched in the regions of the chromatin that were more accessible in embryonic RGCs. Proteomic analysis of purified rat RGC nuclei confirmed the expression of TFs with potential role in axon growth such as CREB, CTCF, YY1, and JUND. The CREB/ATF binding motif was widespread at the open chromatin region of known pro-regenerative TFs, supporting a role of CREB in regulating axon regeneration. Consistently, overexpression of CREB fused to the VP64 transactivation domain in mouse RGCs promoted axon regeneration after optic nerve injury. Our study provides a map of the chromatin accessibility during RGC development and highlights that TF associated with developmental axon growth can stimulate axon regeneration in mature RGC.
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Affiliation(s)
- Wolfgang Pita-Thomas
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO, 63110, USA
| | | | - Ajeet Kumar
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Guoyan Zhao
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO, 63110, USA. .,Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, 63110, USA.
| | - Valeria Cavalli
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO, 63110, USA. .,Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA. .,Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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Zhang Y, Meng T, Chen J, Zhang Y, Kang J, Li X, Yu G, Tian L, Jin Z, Dong H, Zhang X, Ning B. miR-21a-5p Promotes Inflammation following Traumatic Spinal Cord Injury through Upregulation of Neurotoxic Reactive Astrocyte (A1) Polarization by Inhibiting the CNTF/STAT3/Nkrf Pathway. Int J Biol Sci 2021; 17:2795-2810. [PMID: 34345208 PMCID: PMC8326122 DOI: 10.7150/ijbs.60509] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/16/2021] [Indexed: 01/05/2023] Open
Abstract
Reactive astrocytes are implicated in traumatic spinal cord injury (TSCI). Interestingly, naïve astrocytes can easily transform into neurotoxic reactive astrocytes (A1s) with inflammatory stimulation. Previous studies demonstrated that microRNA(miR)-21a-5p was up-regulated in spinal cord tissue after TSCI; however, it is not clear whether this affected reactive astrocyte polarization. Here, we aim to detect the effects of miR-21a-5p on the induction of A1 formation and the underlying mechanisms. Our study found that the expression of miR-21a-5p was significantly increased while that of Cntfr α was decreased, since naïve astrocytes transformed into A1s 3 days post-TSCI; the binding site between miR-21a-5p and Cntfr α was further confirmed in astrocytes. After treatment with CNTF, the levels of A1 markers decreased while that of A2 increased. The expression of A1 markers significantly decreased with the downregulation of miR-21a-5p, while Cntfr α siRNA treatment caused the opposite both in vitro and in vivo. To summarize, miR-21a-5p/Cntfr α promotes A1 induction and might enhance the inflammatory process of TSCI; furthermore, we identified, for the first time, the effect and potential mechanism by which CNTF inhibits naïve astrocytes transformation into A1s. Collectively, our findings demonstrate that targeting miR-21a-5p represents a prospective therapy for promoting the recovery of TSCI.
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Affiliation(s)
- Yining Zhang
- Central Hospital Affiliated to Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250013, China
| | - Tingting Meng
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No.105, Jiefang Road, Jinan, Shandong 250013, China
| | - Jianan Chen
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No.105, Jiefang Road, Jinan, Shandong 250013, China
| | - Ying Zhang
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No.105, Jiefang Road, Jinan, Shandong 250013, China
| | - Jianning Kang
- Central Hospital Affiliated to Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250013, China
| | - Xinyu Li
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No.105, Jiefang Road, Jinan, Shandong 250013, China
| | - Guilian Yu
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No.105, Jiefang Road, Jinan, Shandong 250013, China
| | - Lige Tian
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No.105, Jiefang Road, Jinan, Shandong 250013, China
| | - Zhengxin Jin
- Central Hospital Affiliated to Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250013, China
| | - Hui Dong
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No.105, Jiefang Road, Jinan, Shandong 250013, China
| | - Xiaodi Zhang
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Bin Ning
- Central Hospital Affiliated to Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250013, China
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Targeting Canonical and Non-Canonical STAT Signaling Pathways in Renal Diseases. Cells 2021; 10:cells10071610. [PMID: 34199002 PMCID: PMC8305338 DOI: 10.3390/cells10071610] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/16/2021] [Accepted: 06/22/2021] [Indexed: 01/05/2023] Open
Abstract
Signal transducer and activator of transcription (STAT) plays an essential role in the inflammatory reaction and immune response of numerous renal diseases. STATs can transmit the signals of cytokines, chemokines, and growth factors from the cell membrane to the nucleus. In the canonical STAT signaling pathways, upon binding with their cognate receptors, cytokines lead to a caspase of Janus kinases (JAKs) and STATs tyrosine phosphorylation and activation. Besides receptor-associated tyrosine kinases JAKs, receptors with intrinsic tyrosine kinase activities, G-protein coupled receptors, and non-receptor tyrosine kinases can also activate STATs through tyrosine phosphorylation or, alternatively, other post-translational modifications. Activated STATs translocate into the nucleus and mediate the transcription of specific genes, thus mediating the progression of various renal diseases. Non-canonical STAT pathways consist of preassembled receptor complexes, preformed STAT dimers, unphosphorylated STATs (U-STATs), and non-canonical functions including mitochondria modulation, microtubule regulation and heterochromatin stabilization. Most studies targeting STAT signaling pathways have focused on canonical pathways, but research extending into non-canonical STAT pathways would provide novel strategies for treating renal diseases. In this review, we will introduce both canonical and non-canonical STAT pathways and their roles in a variety of renal diseases.
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Liu W, Qaed E, Zhu HG, Dong MX, Tang Z. Non-energy mechanism of phosphocreatine on the protection of cell survival. Biomed Pharmacother 2021; 141:111839. [PMID: 34174505 DOI: 10.1016/j.biopha.2021.111839] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/12/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
If mitochondrial energy availability or oxidative metabolism is altered, patients will suffer from insufficient energy supply Phosphocreatine (PCr) not only acts as an energy carrier, but also acts as an antioxidant and defensive agent to maintain the integrity and stability of the membrane, to maintain ATP homeostasis through regulating mitochondrial respiration. Meanwhile, PCr can enhance calcium balance and reduce morphological pathological changes, ultimately, PCr helps to reduce apoptosis. On the other aspect, the activities of ATP synthase and MitCK play a crucial role in the maintenance of cellular energy metabolic function. It is interesting to note, PCr not only rises the activities of ATP synthase as well as MitCK, but also promotes these two enzymatic reactions. Additionally, PCr can also inhibit mitochondrial permeability transition in a concentration-dependent manner, prevent ROS and CytC from spilling into the cytoplasm, thereby inhibit the release of proapoptotic factors caspase-3 and caspase-9, and eventually, effectively prevent LPS-induced apoptosis of cells. Understandably, PCr prevents the apoptosis caused by abnormal mitochondrial energy metabolism and has a protective role in a non-energy manner. Moreover, recent studies have shown that PCr protects cell survival through PI3K/Akt/eNOS, MAPK pathway, and inhibition of Ang II-induced NF-κB activation. Furthermore, PCr antagonizes oxidative stress through the activation of PI3K/Akt/GSK3b intracellular pathway, PI3K/AKT-PGC1α signaling pathway, while through the promotion of SIRT3 expression to maintain normal cell metabolism. Interestingly, PCr results in delaying the time to enter pathological metabolism through the delayed activation of AMPK pathway, which is different from previous studies, now we propose the hypothesis that the "miRNA-JAK2/STAT3 -CypD pathway" may take part in protecting cells from apoptosis, PCr may be further be involved in the dynamic relationship between CypD and STAT3. Furthermore, we believe that PCr and CypD would be the central link to maintain cell survival and maintain cell stability and mitochondrial repair under the mitochondrial dysfunction caused by oxidative stress. This review provides the modern progress knowledge and views on the molecular mechanism and molecular targets of PCr in a non-energy way.
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Affiliation(s)
- Wu Liu
- Department of Pharmacology, Dalian Medical University, 9 West Section, South Road of Lushun, 116044 Dalian, China
| | - Eskandar Qaed
- Department of Pharmacology, Dalian Medical University, 9 West Section, South Road of Lushun, 116044 Dalian, China
| | - Han Guo Zhu
- Department of Pharmacology, Dalian Medical University, 9 West Section, South Road of Lushun, 116044 Dalian, China
| | - Ma Xiao Dong
- Department of Pharmacology, Dalian Medical University, 9 West Section, South Road of Lushun, 116044 Dalian, China
| | - ZeYao Tang
- Department of Pharmacology, Dalian Medical University, 9 West Section, South Road of Lushun, 116044 Dalian, China.
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Wang Q, Gong L, Mao S, Yao C, Liu M, Wang Y, Yang J, Yu B, Chen G, Gu X. Klf2-Vav1-Rac1 axis promotes axon regeneration after peripheral nerve injury. Exp Neurol 2021; 343:113788. [PMID: 34147481 DOI: 10.1016/j.expneurol.2021.113788] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 05/03/2021] [Accepted: 06/16/2021] [Indexed: 11/28/2022]
Abstract
Increasing the intrinsic regeneration potential of neurons is the key to promote axon regeneration and repair of nerve injury. Therefore, identifying the molecular switches that respond to nerve injury may play critical role in improving intrinsic regeneration ability. The mechanisms by which injury unlocks the intrinsic axonal growth competence of mature neurons are not well understood. The present study identified the key regulatory genes after sciatic nerve crush injury by RNA sequencing (RNA-Seq) and found that the hub gene Vav1 was highly expressed at both early response and regenerative stages of sciatic nerve injury. Furthermore, Vav1 was required for axon regeneration of dorsal root ganglia (DRG) neurons and functional recovery. Krüppel-like factor 2 (Klf2) was induced by retrograde Ca2+ signaling from injured axons and could directly promote Vav1 transcription in adult DRG neurons. The increased Vav1 then promoted axon regeneration by activating Rac1 GTPase independent of its tyrosine phosphorylation. Collectively, these findings break through previous limited cognition of Vav1, and first reveal a crucial role of Vav1 as a molecular switch in response to axonal injury for promoting axon regeneration, which might further serve as a novel molecular therapeutic target for clinical nerve injury repair.
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Affiliation(s)
- Qihui Wang
- Ministry of Education (MOE) Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210061, China; Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Leilei Gong
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Susu Mao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Chun Yao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Mingwen Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Yaxian Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Jian Yang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Bin Yu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Guiquan Chen
- Ministry of Education (MOE) Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210061, China.
| | - Xiaosong Gu
- Ministry of Education (MOE) Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210061, China; Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China.
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33
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Venkatesh I, Mehra V, Wang Z, Simpson MT, Eastwood E, Chakraborty A, Beine Z, Gross D, Cabahug M, Olson G, Blackmore MG. Co-occupancy identifies transcription factor co-operation for axon growth. Nat Commun 2021; 12:2555. [PMID: 33953205 PMCID: PMC8099911 DOI: 10.1038/s41467-021-22828-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 03/29/2021] [Indexed: 12/13/2022] Open
Abstract
Transcription factors (TFs) act as powerful levers to regulate neural physiology and can be targeted to improve cellular responses to injury or disease. Because TFs often depend on cooperative activity, a major challenge is to identify and deploy optimal sets. Here we developed a bioinformatics pipeline, centered on TF co-occupancy of regulatory DNA, and used it to predict factors that potentiate the effects of pro-regenerative Klf6 in vitro. High content screens of neurite outgrowth identified cooperative activity by 12 candidates, and systematic testing in a mouse model of corticospinal tract (CST) damage substantiated three novel instances of pairwise cooperation. Combined Klf6 and Nr5a2 drove the strongest growth, and transcriptional profiling of CST neurons identified Klf6/Nr5a2-responsive gene networks involved in macromolecule biosynthesis and DNA repair. These data identify TF combinations that promote enhanced CST growth, clarify the transcriptional correlates, and provide a bioinformatics approach to detect TF cooperation.
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Affiliation(s)
- Ishwariya Venkatesh
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA.
| | - Vatsal Mehra
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Zimei Wang
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Matthew T Simpson
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Erik Eastwood
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | | | - Zac Beine
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Derek Gross
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Michael Cabahug
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Greta Olson
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Murray G Blackmore
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA.
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Lee N, Lee MY, Lee J, Kwon SH, Seung H, Lim J, Kim S. Hepatocyte growth factor induces pErk and pSTAT3 (Ser 727) to promote mitochondrial activity and neurite outgrowth in primary dorsal root ganglion cultures. Neuroreport 2021; 32:525-530. [PMID: 33788814 DOI: 10.1097/wnr.0000000000001622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hepatocyte growth factor (HGF) promotes the neurite outgrowth of sensory neurons in developmental stages, but its role in injured peripheral nerves in adult mice remains largely been unexplored. In this study, we investigated the role of HGF in the regeneration of injured peripheral nerves using cultured dorsal root ganglions (DRGs). When cells were treated with HGF protein, the length of the neurite was increased 1.4-fold compared to the untreated control group. HGF greatly increased the level of phosphorylated STAT3 at serine 727 [pSTAT3 (Ser 727)], thereby translocating the protein to the mitochondria. HGF treatment increased the activity of mitochondrial complex I. When DRGs were cultured in the presence of U0126, a pharmacological inhibitor of Erk, the HGF-mediated increase in neurite outgrowth and the level of pSTAT3 (Ser 727) were both suppressed. Taken together, these results suggest that the HGF/c-met pathway might promote neurite outgrowth by controlling mitochondrial activity through the HGF/Erk/STAT3 axis.
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Affiliation(s)
- Nayeon Lee
- Department of Biological Sciences, Seoul National University.,Division of Gene Therapy, Helixmith Co Ltd., Seoul, Korea
| | - Mi-Young Lee
- Division of Gene Therapy, Helixmith Co Ltd., Seoul, Korea
| | - Junghun Lee
- Division of Gene Therapy, Helixmith Co Ltd., Seoul, Korea
| | - Sang Ho Kwon
- Division of Gene Therapy, Helixmith Co Ltd., Seoul, Korea
| | - Hana Seung
- Division of Gene Therapy, Helixmith Co Ltd., Seoul, Korea
| | - Jaegook Lim
- Division of Gene Therapy, Helixmith Co Ltd., Seoul, Korea
| | - Sunyoung Kim
- Division of Gene Therapy, Helixmith Co Ltd., Seoul, Korea
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Wang B, Huang M, Shang D, Yan X, Zhao B, Zhang X. Mitochondrial Behavior in Axon Degeneration and Regeneration. Front Aging Neurosci 2021; 13:650038. [PMID: 33762926 PMCID: PMC7982458 DOI: 10.3389/fnagi.2021.650038] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/18/2021] [Indexed: 12/19/2022] Open
Abstract
Mitochondria are organelles responsible for bioenergetic metabolism, calcium homeostasis, and signal transmission essential for neurons due to their high energy consumption. Accumulating evidence has demonstrated that mitochondria play a key role in axon degeneration and regeneration under physiological and pathological conditions. Mitochondrial dysfunction occurs at an early stage of axon degeneration and involves oxidative stress, energy deficiency, imbalance of mitochondrial dynamics, defects in mitochondrial transport, and mitophagy dysregulation. The restoration of these defective mitochondria by enhancing mitochondrial transport, clearance of reactive oxidative species (ROS), and improving bioenergetic can greatly contribute to axon regeneration. In this paper, we focus on the biological behavior of axonal mitochondria in aging, injury (e.g., traumatic brain and spinal cord injury), and neurodegenerative diseases (Alzheimer's disease, AD; Parkinson's disease, PD; Amyotrophic lateral sclerosis, ALS) and consider the role of mitochondria in axon regeneration. We also compare the behavior of mitochondria in different diseases and outline novel therapeutic strategies for addressing abnormal mitochondrial biological behavior to promote axonal regeneration in neurological diseases and injuries.
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Affiliation(s)
- Biyao Wang
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Minghao Huang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Dehao Shang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xu Yan
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Baohong Zhao
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xinwen Zhang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
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36
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Axonal Organelles as Molecular Platforms for Axon Growth and Regeneration after Injury. Int J Mol Sci 2021; 22:ijms22041798. [PMID: 33670312 PMCID: PMC7918155 DOI: 10.3390/ijms22041798] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
Investigating the molecular mechanisms governing developmental axon growth has been a useful approach for identifying new strategies for boosting axon regeneration after injury, with the goal of treating debilitating conditions such as spinal cord injury and vision loss. The picture emerging is that various axonal organelles are important centers for organizing the molecular mechanisms and machinery required for growth cone development and axon extension, and these have recently been targeted to stimulate robust regeneration in the injured adult central nervous system (CNS). This review summarizes recent literature highlighting a central role for organelles such as recycling endosomes, the endoplasmic reticulum, mitochondria, lysosomes, autophagosomes and the proteasome in developmental axon growth, and describes how these organelles can be targeted to promote axon regeneration after injury to the adult CNS. This review also examines the connections between these organelles in developing and regenerating axons, and finally discusses the molecular mechanisms within the axon that are required for successful axon growth.
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Lu Y, Brommer B, Tian X, Krishnan A, Meer M, Wang C, Vera DL, Zeng Q, Yu D, Bonkowski MS, Yang JH, Zhou S, Hoffmann EM, Karg MM, Schultz MB, Kane AE, Davidsohn N, Korobkina E, Chwalek K, Rajman LA, Church GM, Hochedlinger K, Gladyshev VN, Horvath S, Levine ME, Gregory-Ksander MS, Ksander BR, He Z, Sinclair DA. Reprogramming to recover youthful epigenetic information and restore vision. Nature 2020; 588:124-129. [PMID: 33268865 PMCID: PMC7752134 DOI: 10.1038/s41586-020-2975-4] [Citation(s) in RCA: 360] [Impact Index Per Article: 90.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/22/2020] [Indexed: 02/07/2023]
Abstract
Ageing is a degenerative process that leads to tissue dysfunction and death. A proposed cause of ageing is the accumulation of epigenetic noise that disrupts gene expression patterns, leading to decreases in tissue function and regenerative capacity1-3. Changes to DNA methylation patterns over time form the basis of ageing clocks4, but whether older individuals retain the information needed to restore these patterns-and, if so, whether this could improve tissue function-is not known. Over time, the central nervous system (CNS) loses function and regenerative capacity5-7. Using the eye as a model CNS tissue, here we show that ectopic expression of Oct4 (also known as Pou5f1), Sox2 and Klf4 genes (OSK) in mouse retinal ganglion cells restores youthful DNA methylation patterns and transcriptomes, promotes axon regeneration after injury, and reverses vision loss in a mouse model of glaucoma and in aged mice. The beneficial effects of OSK-induced reprogramming in axon regeneration and vision require the DNA demethylases TET1 and TET2. These data indicate that mammalian tissues retain a record of youthful epigenetic information-encoded in part by DNA methylation-that can be accessed to improve tissue function and promote regeneration in vivo.
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Affiliation(s)
- Yuancheng Lu
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Benedikt Brommer
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Xiao Tian
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Anitha Krishnan
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Margarita Meer
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Yale School of Medicine, New Haven, CT, USA
| | - Chen Wang
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Daniel L Vera
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Qiurui Zeng
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Doudou Yu
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Michael S Bonkowski
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Jae-Hyun Yang
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Songlin Zhou
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Emma M Hoffmann
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Margarete M Karg
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Michael B Schultz
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Alice E Kane
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Noah Davidsohn
- Department of Genetics, Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Ekaterina Korobkina
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Karolina Chwalek
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - Luis A Rajman
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA
| | - George M Church
- Department of Genetics, Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Konrad Hochedlinger
- Department of Molecular Biology, Cancer Center and Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Vadim N Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Steve Horvath
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Morgan E Levine
- Department of Pathology, Yale School of Medicine, New Haven, CT, USA
| | - Meredith S Gregory-Ksander
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Bruce R Ksander
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Zhigang He
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - David A Sinclair
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for Biology of Aging Research, Harvard Medical School, Boston, MA, USA.
- Laboratory for Ageing Research, Department of Pharmacology, School of Medical Sciences, The University of New South Wales, Sydney, New South Wales, Australia.
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Hwang J, Namgung U. Phosphorylation of STAT3 by axonal Cdk5 promotes axonal regeneration by modulating mitochondrial activity. Exp Neurol 2020; 335:113511. [PMID: 33098871 DOI: 10.1016/j.expneurol.2020.113511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 09/14/2020] [Accepted: 10/17/2020] [Indexed: 01/03/2023]
Abstract
Cyclin-dependent kinase 5 (Cdk5) is involved in neural organization and synaptic functions in developing and adult brains, yet its role in axonal regeneration is not known well. Here, we characterize Cdk5 function for axonal regeneration after peripheral nerve injury. Levels of Cdk5 and p25 were elevated in sciatic nerve axons after injury. Cdk5 activity was concomitantly induced from injured nerve and increased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) on the serine 727 residue. Pharmacological and genetic blockades of Cdk5 activity phosphorylating STAT3 resulted in the inhibition of axonal regeneration as evidenced by reduction of retrograde labeling of dorsal root ganglion (DRG) sensory neurons and spinal motor neurons and also of neurite outgrowth of preconditioned DRG neurons in culture. Cdk5 and STAT3 were found in mitochondrial membranes of the injured sciatic nerve. Cdk5-GFP, which was translocated into the mitochondria by the mitochondrial target sequence (MTS), induced STAT3 phosphorylation in transfected DRG neurons and was sufficient to induce neurite outgrowth. In the mitochondria, Cdk5 activity was positively correlated with increased mitochondrial membrane potential as measured by fluorescence intensity of JC-1 aggregates. Our data suggest that Cdk5 may play a role in modulating mitochondrial activity through STAT3 phosphorylation, thereby promoting axonal regeneration.
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Affiliation(s)
- Jinyeon Hwang
- Neurophysiology Laboratory, Department of Oriental Medicine, Institute of Bioscience and Integrative Medicine, Daejeon University, Daehak-ro 62, Daejeon 34520, South Korea
| | - Uk Namgung
- Neurophysiology Laboratory, Department of Oriental Medicine, Institute of Bioscience and Integrative Medicine, Daejeon University, Daehak-ro 62, Daejeon 34520, South Korea.
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Qian C, Zhou FQ. Updates and challenges of axon regeneration in the mammalian central nervous system. J Mol Cell Biol 2020; 12:798-806. [PMID: 32470988 PMCID: PMC7816684 DOI: 10.1093/jmcb/mjaa026] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 05/01/2020] [Accepted: 05/26/2020] [Indexed: 02/07/2023] Open
Abstract
Axon regeneration in the mammalian central nervous system (CNS) has been a long-standing and highly challenging issue. Successful CNS axon regeneration will benefit many human diseases involving axonal damage, such as spinal cord injury, traumatic brain injury, glaucoma, and neurodegenerative diseases. The current consensus is that the diminished intrinsic regenerative ability in mature CNS neurons and the presence of extrinsic inhibitors blocking axon regrowth are two major barriers for axon regeneration. During the past decade, studies targeting the intrinsic axon growth ability via regulation of gene transcription have produced very promising results in optic nerve and/or spinal cord regeneration. Manipulations of various signaling pathways or the nuclear transcription factors directly have been shown to sufficiently drive CNS axon regrowth. Converging evidence reveals that some pro-regenerative transcriptomic states, which are commonly accomplished by more comprehensive epigenetic regulations, exist to orchestrate the complex tasks of injury sensing and axon regeneration. Moreover, genetic reprogramming achieved via transcriptome and epigenome modifications provides novel mechanisms for enhancing axon regeneration. Recent studies also highlighted the important roles of remodeling neuronal cytoskeleton in overcoming the extrinsic inhibitory cues. However, our knowledge about the cellular and molecular mechanisms by which neurons regulate their intrinsic axon regeneration ability and response to extrinsic inhibitory cues is still fragmented. Here, we provide an update about recent research progress in axon regeneration and discuss major remaining challenges for long-distance axon regeneration and the subsequent functional recovery.
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Affiliation(s)
- Cheng Qian
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Feng-Quan Zhou
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.,The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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Neural Cadherin Plays Distinct Roles for Neuronal Survival and Axon Growth under Different Regenerative Conditions. eNeuro 2020; 7:ENEURO.0325-20.2020. [PMID: 32967889 PMCID: PMC7688304 DOI: 10.1523/eneuro.0325-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/18/2022] Open
Abstract
Growing axons in the CNS often migrate along specific pathways to reach their targets. During embryonic development, this migration is guided by different types of cell adhesion molecules (CAMs) present on the surface of glial cells or other neurons, including the neural cadherin (NCAD). Axons in the adult CNS can be stimulated to regenerate, and travel long distances. Crucially, however, while a few axons are guided effectively through the injured nerve under certain conditions, most axons never migrate properly. The molecular underpinnings of the variable growth, and the glial CAMs that are responsible for CNS axon regeneration remain unclear. Here we used optic nerve crush to demonstrate that NCAD plays multifaceted functions in facilitating CNS axon regeneration. Astrocyte-specific deletion of NCAD dramatically decreases regeneration induced by phosphatase and tensin homolog (PTEN) ablation in retinal ganglion cells (RGCs). Consistent with NCAD’s tendency to act as homodimers, deletion of NCAD in RGCs also reduces regeneration. Deletion of NCAD in astrocytes neither alters RGCs’ mammalian target of rapamycin complex 1 (mTORC1) activity nor lesion size, two factors known to affect regeneration. Unexpectedly, however, we find that NCAD deletion in RGCs reduces PTEN-deletion-induced RGC survival. We further show that NCAD deletion, in either astrocytes or RGCs, has negligible effects on the regeneration induced by ciliary neurotrophic factor (CNTF), suggesting that other CAMs are critical under this regenerative condition. Consistent with this notion, CNTF induces expression various integrins known to mediate cell adhesion. Together, our study reveals multilayered functions of NCAD and a molecular basis of variability in guided axon growth.
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Cdk5 Phosphorylation of STAT3 in Dorsal Root Ganglion Neurons Is Involved in Promoting Axonal Regeneration After Peripheral Nerve Injury. Int Neurourol J 2020; 24:S19-27. [PMID: 32482054 PMCID: PMC7285696 DOI: 10.5213/inj.2040158.080] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/07/2020] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The goal of this study is to investigate the role of cyclin-dependent kinase 5 (Cdk5) in axonal regeneration in dorsal root ganglion (DRG) neurons after peripheral nerve injury. METHODS Crush injury was given on the sciatic nerve in rats. The DRG tissues were prepared 1, 3, and 7 days after injury and used for western blotting and immunofluorescence staining experiments. Primary DRG neurons were prepared and treated with Cdk5 inhibitor roscovitine or used for transfections with plasmid constructs. After immunofluorescence staining, neurite length of DRG neurons was analyzed and compared among experimental groups. In addition, roscovitine was injected into the DRG in vivo, and the sciatic nerve after injury was prepared and used for immunofluorescence staining to analyze axonal regeneration in nerve sections. RESULTS Levels of Cdk5 and p25 were increased in DRG neurons after sciatic nerve injury (SNI). Levels of S727-p-STAT3, but not Y705-p-STAT3, were increased in the DRG. Immunofluorescence staining revealed that Cdk5 and STAT3 proteins were mostly colocalized in DRG neurons and Y705-p-STAT3 signals were localized within the nucleus area of DRG neurons. A blockade of Cdk5 activity by roscovitine or by transfection with dominant negative Cdk5 (dn-Cdk5) and nonphosphorylatable forms of STAT3 (S727A or Y705F) resulted in significant reductions of the neurite outgrowth of cultured DRG neurons. In vivo administration of roscovitine into the DRG markedly attenuated distal elongation of regenerating axons in the sciatic nerve after injury. CONCLUSION Our study demonstrated that Cdk5 activity induced from DRG neurons after SNI increased phosphorylation of STAT3. The activation of Cdk5-STAT3 pathway may be involved in promoting axonal regeneration in the peripheral nerve after injury.
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Su Y, Zhang W, Patro CPK, Zhao J, Mu T, Ma Z, Xu J, Ban K, Yi C, Zhou Y. STAT3 Regulates Mouse Neural Progenitor Proliferation and Differentiation by Promoting Mitochondrial Metabolism. Front Cell Dev Biol 2020; 8:362. [PMID: 32509786 PMCID: PMC7248371 DOI: 10.3389/fcell.2020.00362] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/22/2020] [Indexed: 02/05/2023] Open
Abstract
The proliferation and differentiation of neural progenitor lay the foundation for brain development. In neural progenitors, activation of Signal Transducer and Activator of Transcription 3 (STAT3) has been found to promote proliferation and astrocytogenesis while suppressing neurogenesis. However, our study found that Stat3 conditional knockout in neural progenitors (Stat3 cKO) also results in increased proliferation and suppressed neurogenesis. To investigate how STAT3 regulates these processes, we attempted to identify potential STAT3 target genes by RNA-seq profiling of the control (CTL) and Stat3 cKO neural progenitors. We found that STAT3 promotes the expression of genes involved in the mitochondrial oxidative phosphorylation (OXPHOS), and thereby promotes mitochondrial respiration and negatively regulates reactive oxygen species (ROS) production. In addition, we demonstrated that Stat3 loss-of-function promotes proliferation via regulation of mitochondrial metabolism and downstream signaling pathways. Our study provides novel insights into the relation between STAT3, mitochondrial metabolism and the process of embryonic neurogenesis.
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Affiliation(s)
- Yixun Su
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Wenjun Zhang
- School of Medicine, Indiana University, Indianapolis, IN, United States
| | - C Pawan K Patro
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Cancer Science Institute of Singapore, Singapore, Singapore
| | - Jing Zhao
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Tianhao Mu
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Cancer Science Institute of Singapore, Singapore, Singapore
| | - Zhongnan Ma
- Department of Biology, Southern University of Science and Technology, Shenzhen, China.,West China Hospital, Sichuan University, Chengdu, China.,Model Animal Research Center of Nanjing University, Nanjing, China
| | - Jianqiang Xu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Kenneth Ban
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Chenju Yi
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yi Zhou
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, Singapore.,West China Hospital, Sichuan University, Chengdu, China
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Yang SG, Li CP, Peng XQ, Teng ZQ, Liu CM, Zhou FQ. Strategies to Promote Long-Distance Optic Nerve Regeneration. Front Cell Neurosci 2020; 14:119. [PMID: 32477071 PMCID: PMC7240020 DOI: 10.3389/fncel.2020.00119] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/14/2020] [Indexed: 02/06/2023] Open
Abstract
Mammalian retinal ganglion cells (RGCs) in the central nervous system (CNS) often die after optic nerve injury and surviving RGCs fail to regenerate their axons, eventually resulting in irreversible vision loss. Manipulation of a diverse group of genes can significantly boost optic nerve regeneration of mature RGCs by reactivating developmental-like growth programs or suppressing growth inhibitory pathways. By injury of the vision pathway near their brain targets, a few studies have shown that regenerated RGC axons could form functional synapses with targeted neurons but exhibited poor neural conduction or partial functional recovery. Therefore, the functional restoration of eye-to-brain pathways remains a greatly challenging issue. Here, we review recent advances in long-distance optic nerve regeneration and the subsequent reconnecting to central targets. By summarizing our current strategies for promoting functional recovery, we hope to provide potential insights into future exploration in vision reformation after neural injuries.
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Affiliation(s)
- Shu-Guang Yang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Chang-Ping Li
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xue-Qi Peng
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhao-Qian Teng
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Chang-Mei Liu
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng-Quan Zhou
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, United States.,The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Regenerative Potential of Carbon Monoxide in Adult Neural Circuits of the Central Nervous System. Int J Mol Sci 2020; 21:ijms21072273. [PMID: 32218342 PMCID: PMC7177523 DOI: 10.3390/ijms21072273] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/17/2020] [Accepted: 03/23/2020] [Indexed: 01/04/2023] Open
Abstract
Regeneration of adult neural circuits after an injury is limited in the central nervous system (CNS). Heme oxygenase (HO) is an enzyme that produces HO metabolites, such as carbon monoxide (CO), biliverdin and iron by heme degradation. CO may act as a biological signal transduction effector in CNS regeneration by stimulating neuronal intrinsic and extrinsic mechanisms as well as mitochondrial biogenesis. CO may give directions by which the injured neurovascular system switches into regeneration mode by stimulating endogenous neural stem cells and endothelial cells to produce neurons and vessels capable of replacing injured neurons and vessels in the CNS. The present review discusses the regenerative potential of CO in acute and chronic neuroinflammatory diseases of the CNS, such as stroke, traumatic brain injury, multiple sclerosis and Alzheimer’s disease and the role of signaling pathways and neurotrophic factors. CO-mediated facilitation of cellular communications may boost regeneration, consequently forming functional adult neural circuits in CNS injury.
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Rewiring Neuronal Glycerolipid Metabolism Determines the Extent of Axon Regeneration. Neuron 2019; 105:276-292.e5. [PMID: 31786011 PMCID: PMC6975164 DOI: 10.1016/j.neuron.2019.10.009] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 09/11/2019] [Accepted: 10/03/2019] [Indexed: 12/21/2022]
Abstract
How adult neurons coordinate lipid metabolism to regenerate axons remains elusive. We found that depleting neuronal lipin1, a key enzyme controlling the balanced synthesis of glycerolipids through the glycerol phosphate pathway, enhanced axon regeneration after optic nerve injury. Axotomy elevated lipin1 in retinal ganglion cells, which contributed to regeneration failure in the CNS by favorably producing triglyceride (TG) storage lipids rather than phospholipid (PL) membrane lipids in neurons. Regrowth induced by lipin1 depletion required TG hydrolysis and PL synthesis. Decreasing TG synthesis by deleting neuronal diglyceride acyltransferases (DGATs) and enhancing PL synthesis through the Kennedy pathway promoted axon regeneration. In addition, peripheral neurons adopted this mechanism for their spontaneous axon regeneration. Our study reveals a critical role of lipin1 and DGATs as intrinsic regulators of glycerolipid metabolism in neurons and indicates that directing neuronal lipid synthesis away from TG synthesis and toward PL synthesis may promote axon regeneration. Injury-elevated Lipin1 and DGAT in retinal ganglion cells suppress regeneration Neuronal lipin1 and DGATs increase triglyceride and decrease phospholipids Redirecting triacylglyceride to phospholipid synthesis promotes axon regeneration
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Wang S, Smith GM, Selzer ME, Li S. Emerging molecular therapeutic targets for spinal cord injury. Expert Opin Ther Targets 2019; 23:787-803. [PMID: 31460807 DOI: 10.1080/14728222.2019.1661381] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Introduction: Spinal cord injury (SCI) is a complicated and devastating neurological disorder. Patients with SCI usually have dramatically reduced quality of life. In recent years, numerous studies have reported advances in understanding the pathophysiology of SCI and developing preclinical therapeutic strategies for SCI, including various molecular therapies, and yet there is still no cure. Areas covered: After SCI, tissue damage, responses and repair involve interactions among many cellular components, including neurons, axons, glia, leukocytes, and other cells. Accordingly, numerous cellular genes and molecules have become therapeutic targets for neural tissue repair, circuit reconstruction, and behavioral restoration. Here, we review the major recent advances in biological and molecular strategies to enhance neuroprotection, axon regeneration, remyelination, neuroplasticity and functional recovery in preclinical studies of SCI. Expert opinion: Researchers have made tremendous progress in identifying individual and combined molecular therapies in animal studies. It is very important to identify additional highly effective treatments for early neuroprotective intervention and for functionally meaningful axon regeneration and neuronal reconnections. Because multiple mechanisms contribute to the functional loss after SCI, combining the most promising approaches that target different pathophysiological and molecular mechanisms should exhibit synergistic actions for maximal functional restoration. [Databases searched: PubMed; inclusive dates: 6/27/2019].
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Affiliation(s)
- Shuo Wang
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Anatomy and Cell Biology, Temple University School of Medicine , Philadelphia , PA , USA
| | - George M Smith
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Neuroscience, Temple University School of Medicine , Philadelphia , PA , USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Neurology, Temple University School of Medicine , Philadelphia , PA , USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Anatomy and Cell Biology, Temple University School of Medicine , Philadelphia , PA , USA
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Abstract
Permanent disabilities following CNS injuries result from the failure of injured axons to regenerate and rebuild functional connections with their original targets. By contrast, injury to peripheral nerves is followed by robust regeneration, which can lead to recovery of sensory and motor functions. This regenerative response requires the induction of widespread transcriptional and epigenetic changes in injured neurons. Considerable progress has been made in recent years in understanding how peripheral axon injury elicits these widespread changes through the coordinated actions of transcription factors, epigenetic modifiers and, to a lesser extent, microRNAs. Although many questions remain about the interplay between these mechanisms, these new findings provide important insights into the pivotal role of coordinated gene expression and chromatin remodelling in the neuronal response to injury.
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Affiliation(s)
- Marcus Mahar
- Department of Neuroscience, Hope Center for Neurological Disorders and Center of Regenerative Medicine, Washington University School of Medicine, St Louis, MO, USA
| | - Valeria Cavalli
- Department of Neuroscience, Hope Center for Neurological Disorders and Center of Regenerative Medicine, Washington University School of Medicine, St Louis, MO, USA.
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Kreymerman A, Buickians DN, Nahmou MM, Tran T, Galvao J, Wang Y, Sun N, Bazik L, Huynh SK, Cho IJ, Boczek T, Chang KC, Kunzevitzky NJ, Goldberg JL. MTP18 is a Novel Regulator of Mitochondrial Fission in CNS Neuron Development, Axonal Growth, and Injury Responses. Sci Rep 2019; 9:10669. [PMID: 31337818 PMCID: PMC6650498 DOI: 10.1038/s41598-019-46956-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/05/2019] [Indexed: 12/17/2022] Open
Abstract
The process of mitochondrial fission-fusion has been implicated in diverse neuronal roles including neuronal survival, axon degeneration, and axon regeneration. However, whether increased fission or fusion is beneficial for neuronal health and/or axonal growth is not entirely clear, and is likely situational and cell type-dependent. In searching for mitochondrial fission-fusion regulating proteins for improving axonal growth within the visual system, we uncover that mitochondrial fission process 1,18 kDa (MTP18/MTFP1), a pro-fission protein within the CNS, is critical to maintaining mitochondrial size and volume under normal and injury conditions, in retinal ganglion cells (RGCs). We demonstrate that MTP18’s expression is regulated by transcription factors involved in axonal growth, Kruppel-like factor (KLF) transcription factors-7 and -9, and that knockdown of MTP18 promotes axon growth. This investigation exposes MTP18’s previously unexplored role in regulating mitochondrial fission, implicates MTP18 as a downstream component of axon regenerative signaling, and ultimately lays the groundwork for investigations on the therapeutic efficacy of MTP18 expression suppression during CNS axon degenerative events.
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Affiliation(s)
- Alexander Kreymerman
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA. .,University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| | - David N Buickians
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - Michael M Nahmou
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - Tammy Tran
- University of California, San Diego, CA, 92093, USA
| | - Joana Galvao
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - Yan Wang
- University of California, San Diego, CA, 92093, USA
| | - Nicholas Sun
- University of California, San Diego, CA, 92093, USA
| | - Leah Bazik
- University of California, San Diego, CA, 92093, USA
| | - Star K Huynh
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - In-Jae Cho
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - Tomasz Boczek
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - Kun-Che Chang
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - Noelia J Kunzevitzky
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
| | - Jeffrey L Goldberg
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, CA, 94303, USA
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Dickson RG, Lall VK, Ichiyama RM. Enhancing plasticity in spinal sensorimotor circuits following injuries to facilitate recovery of motor control. CURRENT OPINION IN PHYSIOLOGY 2019. [DOI: 10.1016/j.cophys.2019.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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50
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Abstract
Traumatic brain and spinal cord injuries cause permanent disability. Although progress has been made in understanding the cellular and molecular mechanisms underlying the pathophysiological changes that affect both structure and function after injury to the brain or spinal cord, there are currently no cures for either condition. This may change with the development and application of multi-layer omics, new sophisticated bioinformatics tools, and cutting-edge imaging techniques. Already, these technical advances, when combined, are revealing an unprecedented number of novel cellular and molecular targets that could be manipulated alone or in combination to repair the injured central nervous system with precision. In this review, we highlight recent advances in applying these new technologies to the study of axon regeneration and rebuilding of injured neural circuitry. We then discuss the challenges ahead to translate results produced by these technologies into clinical application to help improve the lives of individuals who have a brain or spinal cord injury.
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Affiliation(s)
- Andrea Tedeschi
- Department of Neuroscience and Discovery Themes Initiative, College of Medicine, Ohio State University, Columbus, Ohio, 43210, USA
| | - Phillip G Popovich
- Center for Brain and Spinal Cord Repair, Institute for Behavioral Medicine Research, Ohio State University, Columbus, Ohio, 43210, USA
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