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Fan B, Chopp M, Zhang Y, Wang X, Kemper A, Zhang ZG, Liu XS. Ablation of Argonaute 2 in Schwann cells accelerates the progression of diabetic peripheral neuropathy. Glia 2023; 71:2196-2209. [PMID: 37178056 PMCID: PMC11057225 DOI: 10.1002/glia.24387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 04/25/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023]
Abstract
Schwann cells (SCs) form myelin and provide metabolic support for axons, and are essential for normal nerve function. Identification of key molecules specific to SCs and nerve fibers may provide new therapeutic targets for diabetic peripheral neuropathy (DPN). Argonaute2 (Ago2) is a key molecular player that mediates the activity of miRNA-guided mRNA cleavage and miRNA stability. Our study found that Ago2 knockout (Ago2-KO) in proteolipid protein (PLP) lineage SCs in mice resulted in a significant reduction of nerve conduction velocities and impairments of thermal and mechanical sensitivities. Histopathological data revealed that Ago2-KO significantly induced demyelination and neurodegeneration. When DPN was induced in both wild-type and Ago2-KO mice, Ago2-KO mice exhibited further decreased myelin thickness and exacerbated neurological outcomes compared with wild-type mice. Deep sequencing analysis of Ago2 immunoprecipitated complexes showed that deregulated miR-206 in Ago2-KO mice is highly related to mitochondrial function. In vitro data showed that knockdown of miR-200 induced mitochondrial dysfunction and apoptosis in SCs. Together, our data suggest that Ago2 in SCs is essential to maintain peripheral nerve function while ablation of Ago2 in SCs exacerbates SC dysfunction and neuronal degeneration in DPN. These findings provide new insight into the molecular mechanisms of DPN.
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Affiliation(s)
- Baoyan Fan
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
- Department of Physics, Oakland University, Rochester, Michigan, USA
| | - Yi Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Xinli Wang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Amy Kemper
- Department of Pathology, Henry Ford Hospital, Detroit, Michigan, USA
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Xian Shuang Liu
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
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Ao Q, Wen LL, Yu TH, Ma YZ, Mao XY, Ao TR, Javed R, Ten H, Matsuno A. Sequential expression of miR-221-3p and miR-338-3p in Schwann cells as a therapeutic strategy to promote nerve regeneration and functional recovery. Neural Regen Res 2023; 18:671-682. [DOI: 10.4103/1673-5374.350214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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3
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Gastrodin promotes the regeneration of peripheral nerves by regulating miR-497/BDNF axis. BMC Complement Med Ther 2022; 22:45. [PMID: 35177060 PMCID: PMC8855574 DOI: 10.1186/s12906-021-03483-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/08/2021] [Indexed: 01/12/2023] Open
Abstract
Background Gastrodin (GAS), is a kind of phenolic compound extracted from the traditional Chinese herbal medicine Gastrodia elata Blume (GEB). This study was aimed at probing into the protective effect of GAS on peripheral nerve injury (PNI) and the underlying mechanism. Methods A rat model with PNI was established, followed by intraperitoneal injection of GAS (20 mg/kg/day). Sciatic nerve function index (SFI) was used to analyze the function of sciatic nerve. The amplitude and latency of compound muscle action potential (CMAP) were examined by electrophysiology. Schwann cells (SCs) were isolated from fetal rats and treated with GAS 200 μg/mL, and H2O2-induced model of oxidative stress injury was established. EdU and Transwell assays were adopted to detect the viability and migration of SCs. Dual-luciferase reporter gene assays were applied to verify the binding site between miR-497 and brain-derived neurotrophic factor (BDNF) 3’UTR. MiR-497 expression was probed by quantitative real-time polymerase chain reaction (qRT-PCR). BDNF, neurofilament-200 (NF-200) and myelin basic protein (MBP) expression levels were detected by Western blotting. Malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, glutathione content (GSH) and catalase (CAT) activity in SCs were also measured. Results GAS treatment could significantly increase the SFI and amplitude of CMAP, shorten the refractory period, and ameliorate muscle atrophy of the rats with PNI. GAS treatment could markedly restrain miR-497 expression and increase the expression levels of BDNF, NF-200 and MBP in SCs. BDNF was confirmed as the target of miR-497 and BDNF overexpression could reverse the impacts of miR-497 overexpression on the proliferation, migration, and oxidative stress response of SCs. Conclusions GAS promotes the recovery of PNI via modulating miR-497 / BDNF axis and inhibiting oxidative stress. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12906-021-03483-z.
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Bischoff JP, Schulz A, Morrison H. The role of exosomes in inter-cellular and inter-organ communication of the peripheral nervous system. FEBS Lett 2022; 596:655-664. [PMID: 34990014 DOI: 10.1002/1873-3468.14274] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/09/2021] [Accepted: 12/23/2021] [Indexed: 11/11/2022]
Abstract
Exosomes, nano-sized extracellular vesicles, are produced via the endosomal pathway and released in the extracellular space upon fusion of multivesicular bodies with the plasma membrane. Recent evidence shows that these extracellular vesicles play a key role in cell-to-cell communication. Exosomes transport bioactive proteins, messenger RNA (mRNAs) and microRNA (miRNAs) in an active form to adjacent cells or to distant organs. In this review, we focus on the role of exosomes in peripheral nerve maintenance and repair, as well as peripheral nerve/organ crosstalk, and discuss the potential benefits of exploiting exosomes for treating PNS injuries. In addition, we will highlight the emerging role of exosomes as new important vehicles for physiological systemic crosstalk failures, which could lead to organ dysfunction during neuroinflammation or aging.
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Affiliation(s)
- Julia Patricia Bischoff
- Leibniz Institute on Aging, Fritz Lipmann Institute, Beutenbergstrasse 11, 07745, Jena, Germany
| | - Alexander Schulz
- Leibniz Institute on Aging, Fritz Lipmann Institute, Beutenbergstrasse 11, 07745, Jena, Germany
| | - Helen Morrison
- Leibniz Institute on Aging, Fritz Lipmann Institute, Beutenbergstrasse 11, 07745, Jena, Germany.,Institute of Biochemistry and Biophysics, Friedrich-Schiller-University Jena, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
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Yin Y, Qu H, Yang Q, Fang Z, Gao R. Astragaloside IV alleviates Schwann cell injury in diabetic peripheral neuropathy by regulating microRNA-155-mediated autophagy. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2021; 92:153749. [PMID: 34601220 DOI: 10.1016/j.phymed.2021.153749] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND MicroRNA-155(miR-155) is closely associated with diabetic peripheral neuropathy (DPN). Astragaloside IV (AST) is a significant extract of Astragalus membranaceus, which has been found to be effective in the treatment of DPN. However, whether astragaloside IV alleviate DPN via regulating miR-155-mediated autophagy remains unclear. PURPOSE This study was designed to evaluate the effects of AST on DPN myelin Schwann cells injury and explore the mechanism of AST in treating DPN for the first time. METHODS GK rats fed with high-fat diet and RSC96 cells cultured in high glucose were used to establish DPN Schwann cells injury in vivo and in vitro model. The effects of AST on DPN were explored through blood glucose detection, nerve function detection, pathological detection and the expression of Neuritin detected by immunohistochemical. To study the effect of AST on the DPN Schwann cells autophagy and the upstream PI3K/Akt/mTOR pathway, the expressions of beclin-1 and LC3 were detected by western blot (WB) in sciatic nerves and by immunofluorescence (IFC) in RSC96 cells. The real-time polymerase chain reaction (RT-PCR) was applied to detect the expressions of miR-155, ATG5, ATG12 both in vivo and in vitro. The binding effect of miR-155 and target gene PI3KCA was verified by luciferase reporter gene assay. The expressions of PI3K, p-Akt/Akt, p-mTOR/mTOR were detected by WB and the expressions of PI3KCA were detected by RT-PCR in vitro. The apoptosis was detected by flow cytometry. Meanwhile, the influence of miR-155 overexpression and knocked down on the above indicators was also detected in RSC96 cells. At last, further mechanism experiments were conducted to verify the mechanism of AST regulating the autophagy and apoptosis of RSC96 cells. RESULTS AST reduced blood glucose levels, alleviated peripheral nerve myelin sheath injury, and improved neurological function in DPN rats. In addition, AST enhanced the autophagy activity and alleviated the apoptosis in RSC96 cell. Mechanism study shown that AST promote autophagy via regulating miR-155-mediated PI3K/Akt/mTOR signaling pathways. AST reduced RSC96 cells apoptosis by promoting autophagy. CONCLUSION AST alleviate the myelin sheath injury of DPN caused by the apoptosis of Schwann cells via enhancing autophagy, which was attributed to inhibiting the activation of the PI3K/Akt/mTOR signaling pathway by upregulating miR-155 expression.
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Affiliation(s)
- Yundong Yin
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China; Postdoctoral Research Station, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Hua Qu
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China; NMPA Key Laboratory for Clinical Research and Evaluation of Traditional Chinese Medicine, Beijing 100091, China; National Clinical Research Center for Chinese Medicine Cardiology, Beijing 100091, China
| | - Qiaoning Yang
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China; NMPA Key Laboratory for Clinical Research and Evaluation of Traditional Chinese Medicine, Beijing 100091, China; National Clinical Research Center for Chinese Medicine Cardiology, Beijing 100091, China
| | - Zhaohui Fang
- The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei 230031, China.
| | - Rui Gao
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China; NMPA Key Laboratory for Clinical Research and Evaluation of Traditional Chinese Medicine, Beijing 100091, China; National Clinical Research Center for Chinese Medicine Cardiology, Beijing 100091, China.
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Sohn EJ, Nam YK, Park HT. Involvement of the miR-363-5p/P2RX4 Axis in Regulating Schwann Cell Phenotype after Nerve Injury. Int J Mol Sci 2021; 22:ijms222111601. [PMID: 34769029 PMCID: PMC8584002 DOI: 10.3390/ijms222111601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 10/22/2021] [Accepted: 10/24/2021] [Indexed: 01/11/2023] Open
Abstract
Although microRNAs (miRNAs or miRs) have been studied in the peripheral nervous system, their function in Schwann cells remains elusive. In this study, we performed a microRNA array analysis of cyclic adenosine monophosphate (cAMP)-induced differentiated primary Schwann cells. KEGG pathway enrichment analysis of the target genes showed that upregulated miRNAs (mR212-5p, miR335, miR20b-5p, miR146b-3p, and miR363-5p) were related to the calcium signaling pathway, regulation of actin cytoskeleton, retrograde endocannabinoid signaling, and central carbon metabolism in cancer. Several key factors, such as purinergic receptors (P2X), guanine nucleotide-binding protein G(olf) subunit alpha (GNAL), P2RX5, P2RX3, platelet-derived growth factor receptor alpha (PDGFRA), and inositol 1,4,5-trisphosphate receptor type 2 (ITPR2; calcium signaling pathway) are potential targets of miRNAs regulating cAMP. Our analysis revealed that miRNAs were differentially expressed in cAMP-treated Schwann cells; miRNA363-5p was upregulated and directly targeted the P2X purinoceptor 4 (P2RX4)-UTR, reducing the luciferase activity of P2RX4. The expression of miRNA363-5p was inhibited and the expression of P2RX4 was upregulated in sciatic nerve injury. In contrast, miRNA363-5p expression was upregulated and P2RX4 expression was downregulated during postnatal development. Of note, a P2RX4 antagonist counteracted myelin degradation after nerve injury and increased pERK and c-Jun expression. Interestingly, a P2RX4 antagonist increased the levels of miRNA363-5p. This study suggests that a double-negative feedback loop between miRNA363-5p and P2RX4 contributes to the dedifferentiation and migration of Schwann cells after nerve injury.
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Affiliation(s)
- Eun-Jung Sohn
- Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 602-714, Korea; (Y.-K.N.); (H.-T.P.)
- School of Medicine, Pusan National University, Yangsan 50612, Korea
- Department of Korean Medical Science, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea
- Correspondence: ; Tel.: +82-051-510-8433; Fax: +82-051-247-3318
| | - Yun-Kyeong Nam
- Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 602-714, Korea; (Y.-K.N.); (H.-T.P.)
| | - Hwan-Tae Park
- Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 602-714, Korea; (Y.-K.N.); (H.-T.P.)
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Sohn EJ, Nam YK. The Transcription Factor TFCP2L1 is Associated with Myelination via miR708-5p Regulation in the Peripheral Nerve System. Neurochem Res 2021; 47:434-445. [PMID: 34581937 DOI: 10.1007/s11064-021-03457-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/25/2021] [Accepted: 09/22/2021] [Indexed: 11/25/2022]
Abstract
MicroRNAs (miRNAs) have been implicated in nerve injury and demyelination; however, their functions in peripheral nerves remain unclear. To determine the potential functions of miRNAs, an miRNA array was carried out. Here, miRNA array analysis of neuregulin-treated Schwann cells revealed 18 upregulated (> 2-fold) and 13 downregulated (> 2-fold) miRNAs. After sciatic nerve injury, miR708-5p was highly expressed in neuregulin-treated Schwann cells, whereas it was downregulated during postnatal development. A predicted functional interaction was found between miR708-5p and transcription factor CP2-like protein 1 (TFCP2L1) using a bioinformatics tool. This finding suggested that miR708-5p may regulate TFCP2L1. During sciatic nerve development, TFCP2L1 was upregulated on postnatal days 1 and 4, while it was downregulated after nerve axotomy and crush injury. Notably, TFCP2L1 was upregulated in cAMP-treated Schwann cells. We also found that activity of the myelin protein zero promoter was downregulated in TFCP2L1 siRNA-treated Schwann cells, whereas it was upregulated in TFCP2L1-overexpressing cells. Immunofluorescence analysis showed that TFCP2L1 was localized in Schwann cells. In addition, miR708-5p overexpression promoted migration of Schwann cells, while miR-708-5p inhibitor inhibited migration. miR708-5p inhibitor also blocked the migration of TFCP2L1 siRNA-treated Schwann cells. These findings indicate the functions of miR708-5p in TFCP2L1 regulation in the peripheral nervous system occur via regulation of Schwann cell migration.
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Affiliation(s)
- Eun Jung Sohn
- Department of Convergence Medical Sciences, School of Medicine, Pusan National University, Pusan National University, Yangsan, South Korea.
| | - Yun Kyung Nam
- Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan, South Korea
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8
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Wrestling and Wrapping: A Perspective on SUMO Proteins in Schwann Cells. Biomolecules 2021; 11:biom11071055. [PMID: 34356679 PMCID: PMC8301837 DOI: 10.3390/biom11071055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 11/20/2022] Open
Abstract
Schwann cell development and peripheral nerve myelination are finely orchestrated multistep processes; some of the underlying mechanisms are well described and others remain unknown. Many posttranslational modifications (PTMs) like phosphorylation and ubiquitination have been reported to play a role during the normal development of the peripheral nervous system (PNS) and in demyelinating neuropathies. However, a relatively novel PTM, SUMOylation, has not been studied in these contexts. SUMOylation involves the covalent attachment of one or more small ubiquitin-like modifier (SUMO) proteins to a substrate, which affects the function, cellular localization, and further PTMs of the conjugated protein. SUMOylation also regulates other proteins indirectly by facilitating non-covalent protein–protein interaction via SUMO interaction motifs (SIM). This pathway has important consequences on diverse cellular processes, and dysregulation of this pathway has been reported in several diseases including neurological and degenerative conditions. In this article, we revise the scarce literature on SUMOylation in Schwann cells and the PNS, we propose putative substrate proteins, and we speculate on potential mechanisms underlying the possible involvement of this PTM in peripheral myelination and neuropathies.
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9
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Stavrou M, Sargiannidou I, Georgiou E, Kagiava A, Kleopa KA. Emerging Therapies for Charcot-Marie-Tooth Inherited Neuropathies. Int J Mol Sci 2021; 22:6048. [PMID: 34205075 PMCID: PMC8199910 DOI: 10.3390/ijms22116048] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited neuropathies known as Charcot-Marie-Tooth (CMT) disease are genetically heterogeneous disorders affecting the peripheral nerves, causing significant and slowly progressive disability over the lifespan. The discovery of their diverse molecular genetic mechanisms over the past three decades has provided the basis for developing a wide range of therapeutics, leading to an exciting era of finding treatments for this, until now, incurable group of diseases. Many treatment approaches, including gene silencing and gene replacement therapies, as well as small molecule treatments are currently in preclinical testing while several have also reached clinical trial stage. Some of the treatment approaches are disease-specific targeted to the unique disease mechanism of each CMT form, while other therapeutics target common pathways shared by several or all CMT types. As promising treatments reach the stage of clinical translation, optimal outcome measures, novel biomarkers and appropriate trial designs are crucial in order to facilitate successful testing and validation of novel treatments for CMT patients.
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Affiliation(s)
- Marina Stavrou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Irene Sargiannidou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Elena Georgiou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Alexia Kagiava
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Kleopas A. Kleopa
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
- Center for Neuromuscular Diseases, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus
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10
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Zolboot N, Du JX, Zampa F, Lippi G. MicroRNAs Instruct and Maintain Cell Type Diversity in the Nervous System. Front Mol Neurosci 2021; 14:646072. [PMID: 33994943 PMCID: PMC8116551 DOI: 10.3389/fnmol.2021.646072] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/30/2021] [Indexed: 12/12/2022] Open
Abstract
Characterizing the diverse cell types that make up the nervous system is essential for understanding how the nervous system is structured and ultimately how it functions. The astonishing range of cellular diversity found in the nervous system emerges from a small pool of neural progenitor cells. These progenitors and their neuronal progeny proceed through sequential gene expression programs to produce different cell lineages and acquire distinct cell fates. These gene expression programs must be tightly regulated in order for the cells to achieve and maintain the proper differentiated state, remain functional throughout life, and avoid cell death. Disruption of developmental programs is associated with a wide range of abnormalities in brain structure and function, further indicating that elucidating their contribution to cellular diversity will be key to understanding brain health. A growing body of evidence suggests that tight regulation of developmental genes requires post-transcriptional regulation of the transcriptome by microRNAs (miRNAs). miRNAs are small non-coding RNAs that function by binding to mRNA targets containing complementary sequences and repressing their translation into protein, thereby providing a layer of precise spatial and temporal control over gene expression. Moreover, the expression profiles and targets of miRNAs show great specificity for distinct cell types, brain regions and developmental stages, suggesting that they are an important parameter of cell type identity. Here, we provide an overview of miRNAs that are critically involved in establishing neural cell identities, focusing on how miRNA-mediated regulation of gene expression modulates neural progenitor expansion, cell fate determination, cell migration, neuronal and glial subtype specification, and finally cell maintenance and survival.
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Affiliation(s)
- Norjin Zolboot
- The Scripps Research Institute, La Jolla, CA, United States
| | - Jessica X Du
- The Scripps Research Institute, La Jolla, CA, United States.,Department of Neurosciences, University of California, San Diego, San Diego, CA, United States
| | - Federico Zampa
- The Scripps Research Institute, La Jolla, CA, United States
| | - Giordano Lippi
- The Scripps Research Institute, La Jolla, CA, United States
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11
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Moss KR, Bopp TS, Johnson AE, Höke A. New evidence for secondary axonal degeneration in demyelinating neuropathies. Neurosci Lett 2021; 744:135595. [PMID: 33359733 PMCID: PMC7852893 DOI: 10.1016/j.neulet.2020.135595] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/31/2020] [Accepted: 12/19/2020] [Indexed: 12/28/2022]
Abstract
Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.
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Affiliation(s)
- Kathryn R Moss
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Taylor S Bopp
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Anna E Johnson
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States.
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12
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Fan B, Chopp M, Zhang ZG, Liu XS. Emerging Roles of microRNAs as Biomarkers and Therapeutic Targets for Diabetic Neuropathy. Front Neurol 2020; 11:558758. [PMID: 33192992 PMCID: PMC7642849 DOI: 10.3389/fneur.2020.558758] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/16/2020] [Indexed: 12/12/2022] Open
Abstract
Diabetic neuropathy (DN) is the most prevalent chronic complication of diabetes mellitus. The exact pathophysiological mechanisms of DN are unclear; however, communication network dysfunction among axons, Schwann cells, and the microvascular endothelium likely play an important role in the development of DN. Mounting evidence suggests that microRNAs (miRNAs) act as messengers that facilitate intercellular communication and may contribute to the pathogenesis of DN. Deregulation of miRNAs is among the initial molecular alterations observed in diabetics. As such, miRNAs hold promise as biomarkers and therapeutic targets. In preclinical studies, miRNA-based treatment of DN has shown evidence of therapeutic potential. But this therapy has been hampered by miRNA instability, targeting specificity, and potential toxicities. Recent findings reveal that when packaged within extracellular vesicles, miRNAs are resistant to degradation, and their delivery efficiency and therapeutic potential is markedly enhanced. Here, we review the latest research progress on the roles of miRNAs as biomarkers and as potential clinical therapeutic targets in DN. We also discuss the promise of exosomal miRNAs as therapeutics and provide recommendations for future research on miRNA-based medicine.
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Affiliation(s)
- Baoyan Fan
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States.,Department of Physics, Oakland University, Rochester, MI, United States
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Xian Shuang Liu
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
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13
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MicroRNAs are indispensable for the proliferation and differentiation of adult neural progenitor cells in mice. Biochem Biophys Res Commun 2020; 530:209-214. [PMID: 32828287 DOI: 10.1016/j.bbrc.2020.06.143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 01/18/2023]
Abstract
More than two decades after the discovery of adult neurogenesis in humans, researchers still struggle to elucidate the underlying transcriptional and post-transcriptional mechanisms. RNA interference is a crucially important process in the central nervous system, and its role in adult neurogenesis is poorly understood. In this work, we address the role of Dicer-dependent microRNA biogenesis in neuronal differentiation of adult neural stem cells within the subventricular zone of the mouse brain. Loss of the Dicer1 gene in the tailless (Tlx)-positive cells did not cause the decline in their numbers, but severely affected differentiation. Thus, our findings identify yet another phenomenon associated with microRNA pathway deregulation in adult neural stem cells which might be of relevance both for neuroscience and clinical practice.
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Thenmozhi R, Lee JS, Park NY, Choi BO, Hong YB. Gene Therapy Options as New Treatment for Inherited Peripheral Neuropathy. Exp Neurobiol 2020; 29:177-188. [PMID: 32624504 PMCID: PMC7344374 DOI: 10.5607/en20004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 04/21/2020] [Accepted: 05/11/2020] [Indexed: 02/06/2023] Open
Abstract
Inherited peripheral neuropathy (IPN) is caused by heterogeneous genetic mutations in more than 100 genes. So far, several treatment options for IPN have been developed and clinically evaluated using small molecules. However, gene therapy-based therapeutic strategies have not been aggressively investigated, likely due to the complexities of inheritance in IPN. Indeed, because the majority of the causative mutations of IPN lead to gain-of-function rather than loss-of-function, developing a therapeutic strategy is more difficult, especially considering gene therapy for genetic diseases began with the simple idea of replacing a defective gene with a functional copy. Recent advances in gene manipulation technology have brought novel approaches to gene therapy and its clinical application for IPN treatment. For example, in addition to the classically used gene replacement for mutant genes in recessively inherited IPN, other techniques including gene addition to modify the disease phenotype, modulations of target gene expression, and techniques to edit mutant genes have been developed and evaluated as potent therapeutic strategies for dominantly inherited IPN. In this review, the current status of gene therapy for IPN and future perspectives will be discussed.
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Affiliation(s)
| | - Ji-Su Lee
- Stem Cell & Regenerative Medicne Institute, Samsung Medical Center, Seoul 06351, Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Na Young Park
- Department of Biochemistry, College of Medicine, Dong-A University, Busan 49201, Korea
| | - Byung-Ok Choi
- Stem Cell & Regenerative Medicne Institute, Samsung Medical Center, Seoul 06351, Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Young Bin Hong
- Department of Biochemistry, College of Medicine, Dong-A University, Busan 49201, Korea
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15
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Lee JS, Kwak G, Kim HJ, Park HT, Choi BO, Hong YB. miR-381 Attenuates Peripheral Neuropathic Phenotype Caused by Overexpression of PMP22. Exp Neurobiol 2019; 28:279-288. [PMID: 31138995 PMCID: PMC6526106 DOI: 10.5607/en.2019.28.2.279] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/05/2019] [Accepted: 04/11/2019] [Indexed: 12/21/2022] Open
Abstract
Charcot-Marie Tooth disease type 1A (CMT1A), the major type of CMT, is caused by duplication of peripheral myelin protein 22 (PMP22) gene whose overexpression causes structural and functional abnormalities in myelination. We investigated whether miRNA-mediated regulation of PMP22 expression could reduce the expression level of PMP22, thereby alleviating the demyelinating neuropathic phenotype of CMT1A. We found that several miRNAs were down-regulated in C22 mouse, a CMT1A mouse model. Among them, miR-381 could target 3′ untranslated region (3′UTR) of PMP22 in vitro based on Western botting and quantitative Real Time-PCR (qRT-PCR) results. In vivo efficacy of miR-381 was assessed by administration of LV-miR-381, an miR-381 expressing lentiviral vector, into the sciatic nerve of C22 mice by a single injection at postnatal day 6 (p6). Administration of LV-miR-381 reduced expression level of PMP22 along with elevated level of miR-381 in the sciatic nerve. Rotarod performance analysis revealed that locomotor coordination of LV-miR-381 administered C22 mice was significantly enhanced from 8 weeks post administration. Electrophysiologically, increased motor nerve conduction velocity was observed in treated mice. Histologically, toluidine blue staining and electron microscopy revealed that structural abnormalities of myelination were improved in sciatic nerves of LV-miR-381 treated mice. Therefore, delivery of miR-381 ameliorated the phenotype of peripheral neuropathy in CMT1A mouse model by down-regulating PMP22 expression. These data suggest that miRNA can be used as a potent therapeutic strategy to control diseases with copy number variations such as CMT1A.
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Affiliation(s)
- Ji-Su Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Geon Kwak
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Hye Jin Kim
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Hwan-Tae Park
- Department of Physiology, College of Medicine, Dong-A University, Busan 49201, Korea
| | - Byung-Ok Choi
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Young Bin Hong
- Department of Biochemistry, College of Medicine, Dong-A University, Busan 49201, Korea
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16
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Jessen KR, Arthur-Farraj P. Repair Schwann cell update: Adaptive reprogramming, EMT, and stemness in regenerating nerves. Glia 2019; 67:421-437. [PMID: 30632639 DOI: 10.1002/glia.23532] [Citation(s) in RCA: 199] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/20/2018] [Accepted: 09/05/2018] [Indexed: 12/16/2022]
Abstract
Schwann cells respond to nerve injury by cellular reprogramming that generates cells specialized for promoting regeneration and repair. These repair cells clear redundant myelin, attract macrophages, support survival of damaged neurons, encourage axonal growth, and guide axons back to their targets. There are interesting parallels between this response and that found in other tissues. At the cellular level, many other tissues also react to injury by cellular reprogramming, generating cells specialized to promote tissue homeostasis and repair. And at the molecular level, a common feature possessed by Schwann cells and many other cells is the injury-induced activation of genes associated with epithelial-mesenchymal transitions and stemness, differentiation states that are linked to cellular plasticity and that help injury-induced tissue remodeling. The number of signaling systems regulating Schwann cell plasticity is rapidly increasing. Importantly, this includes mechanisms that are crucial for the generation of functional repair Schwann cells and nerve regeneration, although they have no or a minor role elsewhere in the Schwann cell lineage. This encourages the view that selective tools can be developed to control these particular cells, amplify their repair supportive functions and prevent their deterioration. In this review, we discuss the emerging similarities between the injury response seen in nerves and in other tissues and survey the transcription factors, epigenetic mechanisms, and signaling cascades that control repair Schwann cells, with emphasis on systems that selectively regulate the Schwann cell injury response.
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Affiliation(s)
- Kristjan R Jessen
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Peter Arthur-Farraj
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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17
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MicroRNAs 93-5p, 106b-5p, 17-5p, and 140-5p target the expression of early growth response protein 2 in Schwann cells. Neuroreport 2019; 30:241-246. [PMID: 30614908 DOI: 10.1097/wnr.0000000000001193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Early growth response protein 2 (EGR2) is an essential transcription factor for peripheral nerve myelination. Schwann cells (SCs), the peripheral myelin-forming glial cells, express high levels of EGR2 during postnatal myelination. In contrast, SCs exhibit low EGR2 expression during Wallerian degeneration after injury. In this study, we screened 10 potential microRNAs (miRNAs) (20a-5p, 137-5p, 140-5p, 148b-3p, 150-5p, 17-5p, 93-5p, 20b-5p, 106b-5p, and 152-3p) that potentially target EGR2 using miRNA algorithms and identified that miRNAs 106b-5p, 140-5p, 93-5p, and 17-5p target EGR2 in SCs. These miRNAs directly target EGR2 by binding to the 3'-untranslated region to suppress EGR2 mRNA levels. Additionally, the levels of miRNAs 93-5p, 106b-5p, 17-5p, and 140-5p were decreased in the sciatic nerves during postnatal development; however, these miRNAs were increased on day 1 after sciatic nerve injury. Taken together, these findings suggest that the expression of EGR2 during postnatal development and Wallerian degeneration could be regulated by the inverse expression of miRNAs 106b-5p, 140-5p, 93-5p, and 17-5p, which target EGR2.
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18
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Ji XM, Wang SS, Cai XD, Wang XH, Liu QY, Wang P, Cheng ZC, Qian TM. Novel miRNA, miR-sc14, promotes Schwann cell proliferation and migration. Neural Regen Res 2019; 14:1651-1656. [PMID: 31089066 PMCID: PMC6557103 DOI: 10.4103/1673-5374.255996] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
MicroRNAs refer to a class of endogenous, short non-coding RNAs that mediate numerous biological functions. MicroRNAs regulate various physiological and pathological activities of peripheral nerves, including peripheral nerve repair and regeneration. Previously, using a rat sciatic nerve injury model, we identified many functionally annotated novel microRNAs, including miR-sc14. Here, we used real-time reverse transcription-polymerase chain reaction to examine miR-sc14 expression in rat sciatic nerve stumps. Our results show that miR-sc14 is noticeably altered following sciatic nerve injury, being up-regulated at 1 day and diminished at 7 days. EdU and transwell chamber assay results showed that miR-sc14 mimic promoted proliferation and migration of Schwann cells, while miR-sc14 inhibitor suppressed their proliferation and migration. Additionally, bioinformatic analysis examined potential target genes of miR-sc14, and found that fibroblast growth factor receptor 2 might be a potential target gene. Specifically, our results show changes of miR-sc14 expression in the sciatic nerve of rats at different time points after nerve injury. Appropriately, up-regulation of miR-sc14 promoted proliferation and migration of Schwann cells. Consequently, miR-sc14 may be an intervention target to promote repair of peripheral nerve injury. The study was approved by the Jiangsu Provincial Laboratory Animal Management Committee, China on March 4, 2015 (approval No. 20150304-004).
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Affiliation(s)
- Xi-Meng Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong; Nonnasality Clinical Medicine, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Shan-Shan Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong; Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiao-Dong Cai
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Xing-Hui Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Qian-Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Pan Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Zhang-Chun Cheng
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Tian-Mei Qian
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
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19
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Gökbuget D, Pereira JA, Opitz L, Christe D, Kessler T, Marchais A, Suter U. The miRNA biogenesis pathway prevents inappropriate expression of injury response genes in developing and adult Schwann cells. Glia 2018; 66:2632-2644. [PMID: 30295958 PMCID: PMC6585637 DOI: 10.1002/glia.23516] [Citation(s) in RCA: 8] [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: 05/29/2018] [Revised: 07/18/2018] [Accepted: 07/18/2018] [Indexed: 12/24/2022]
Abstract
Proper function of the nervous system depends on myelination. In peripheral nerves, Schwann cells (SCs) myelinate axons and the miRNA biogenesis pathway is required for developmental myelination and myelin maintenance. However, regulatory roles of this pathway at different stages of myelination are only partially understood. We addressed the requirement of the core miRNA biogenesis pathway components Dgcr8, Drosha, and Dicer in developing and adult SCs using mouse mutants with a comparative genetics and transcriptomics approach. We found that the microprocessor components Dgcr8 and Drosha are crucial for axonal radial sorting and to establish correct SC numbers upon myelination. Transcriptome analyses revealed a requirement of the microprocessor to prevent aberrantly increased expression of injury-response genes. Those genes are predicted targets of abundant miRNAs in sciatic nerves (SNs) during developmental myelination. In agreement, Dgcr8 and Dicer are required for proper maintenance of the myelinated SC state, where abundant miRNAs in adult SNs are predicted to target injury-response genes. We conclude that the miRNA biogenesis pathway in SCs is crucial for preventing inappropriate activity of injury-response genes in developing and adult SCs.
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Affiliation(s)
- Deniz Gökbuget
- ETH Zurich, Department of BiologyInstitute of Molecular Health SciencesZurichSwitzerland
| | - Jorge A. Pereira
- ETH Zurich, Department of BiologyInstitute of Molecular Health SciencesZurichSwitzerland
| | - Lennart Opitz
- ETH Zurich/University of ZurichFunctional Genomics Center ZurichZurichSwitzerland
| | - Dominik Christe
- ETH Zurich, Department of BiologyInstitute of Molecular Health SciencesZurichSwitzerland
| | - Tobias Kessler
- ETH Zurich, Department of BiologyInstitute of Molecular Health SciencesZurichSwitzerland
| | - Antonin Marchais
- ETH Zurich, Department of BiologyInstitute of Agricultural SciencesZurichSwitzerland
| | - Ueli Suter
- ETH Zurich, Department of BiologyInstitute of Molecular Health SciencesZurichSwitzerland
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20
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Xie YJ, Zhou L, Wang Y, Jiang NW, Cao S, Shao CY, Wang XT, Li XY, Shen Y, Zhou L. Leucine-Rich Glioma Inactivated 1 Promotes Oligodendrocyte Differentiation and Myelination via TSC-mTOR Signaling. Front Mol Neurosci 2018; 11:231. [PMID: 30034322 PMCID: PMC6043672 DOI: 10.3389/fnmol.2018.00231] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022] Open
Abstract
Leucine-rich glioma inactivated 1 (Lgi1), a putative tumor suppressor, is tightly associated with autosomal dominant lateral temporal lobe epilepsy (ADLTE). It has been shown that Lgi1 regulates the myelination of Schwann cells in the peripheral nervous system (PNS). However, the function and underlying mechanisms for Lgi1 regulation of oligodendrocyte differentiation and myelination in the central nervous system (CNS) remain elusive. In addition, whether Lgi1 is required for myelin maintenance is unknown. Here, we show that Lgi1 is necessary and sufficient for the differentiation of oligodendrocyte precursor cells and is also required for the maintenance of myelinated fibers. The hypomyelination in Lgi1-/- mice attributes to the inhibition of the biosynthesis of lipids and proteins in oligodendrocytes (OLs). Moreover, we found that Lgi1 deficiency leads to a decrease in expression of tuberous sclerosis complex 1 (TSC1) and activates mammalian target of rapamycin signaling. Together, the present work establishes that Lgi1 is a regulator of oligodendrocyte development and myelination in CNS.
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Affiliation(s)
- Ya-Jun Xie
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Lin Zhou
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Yin Wang
- Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region, Ningxia Medical UniversityYinchuan, China
| | - Nan-Wei Jiang
- Ningbo Key Laboratory of Behavioral Neuroscience, Department of Physiology and Pharmacology, Ningbo University School of MedicineNingbo, China
| | - Shenglong Cao
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou, China
| | - Chong-Yu Shao
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Xin-Tai Wang
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Xiang-Yao Li
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Ying Shen
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Liang Zhou
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
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21
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Faroni A, Melfi S, Castelnovo LF, Bonalume V, Colleoni D, Magni P, Araúzo-Bravo MJ, Reinbold R, Magnaghi V. GABA-B1 Receptor-Null Schwann Cells Exhibit Compromised In Vitro Myelination. Mol Neurobiol 2018; 56:1461-1474. [PMID: 29948947 DOI: 10.1007/s12035-018-1158-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/28/2018] [Indexed: 12/11/2022]
Abstract
GABA-B receptors are important for Schwann cell (SC) commitment to a non-myelinating phenotype during development. However, the P0-GABA-B1fl/fl conditional knockout mice, lacking the GABA-B1 receptor specifically in SCs, also presented axon modifications, suggesting SC non-autonomous effects through the neuronal compartment. In this in vitro study, we evaluated whether the specific deletion of the GABA-B1 receptor in SCs may induce autonomous or non-autonomous cross-changes in sensory dorsal root ganglia (DRG) neurons. To this end, we performed an in vitro biomolecular and transcriptomic analysis of SC and DRG neuron primary cultures from P0-GABA-B1fl/fl mice. We found that cells from conditional P0-GABA-B1fl/fl mice exhibited proliferative, migratory and myelinating alterations. Moreover, we found transcriptomic changes in novel molecules that are involved in peripheral neuron-SC interaction.
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Affiliation(s)
- Alessandro Faroni
- Blond McIndoe Laboratories, Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Simona Melfi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133, Milan, Italy
| | - Luca Franco Castelnovo
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133, Milan, Italy
| | - Veronica Bonalume
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133, Milan, Italy
| | - Deborah Colleoni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133, Milan, Italy
| | - Paolo Magni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133, Milan, Italy
| | - Marcos J Araúzo-Bravo
- Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute, San Sebastián, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Rolland Reinbold
- Institute of Biomedical Technologies, National Research Council, Milan, Italy
| | - Valerio Magnaghi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133, Milan, Italy.
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22
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Weiner AMJ. MicroRNAs and the neural crest: From induction to differentiation. Mech Dev 2018; 154:98-106. [PMID: 29859253 DOI: 10.1016/j.mod.2018.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/18/2018] [Accepted: 05/28/2018] [Indexed: 01/06/2023]
Abstract
MicroRNAs are small noncoding RNAs that can control gene expression by base pairing to partially complementary mRNAs. Regulation by microRNAs plays essential roles in diverse biological processes such as neural crest formation during embryonic development. The neural crest is a multipotent cell population that develops from the dorsal neural fold of vertebrate embryos in order to migrate extensively and differentiate into a variety of tissues. Gene regulatory networks that coordinate neural crest cell specification and differentiation have been considerably studied so far. Although it is known that microRNAs play important roles in neural crest development, posttranscriptional regulation by microRNAs has not been deeply characterized yet. This review is focused on the microRNAs identified so far in order to regulate gene expression of neural crest cells during vertebrate development.
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Affiliation(s)
- Andrea M J Weiner
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, S2000EZP Rosario, Argentina.
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23
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Li T, Wang J, Wang H, Yang Y, Wang S, Huang N, Wang F, Gao X, Niu J, Li Z, Mei F, Xiao L. The deletion of dicer in mature myelinating glial cells causes progressive axonal degeneration but not overt demyelination in adult mice. Glia 2018; 66:1960-1971. [PMID: 29726608 DOI: 10.1002/glia.23450] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 04/05/2018] [Accepted: 04/05/2018] [Indexed: 01/17/2023]
Abstract
Myelinating glial cells (MGCs), oligodendrocytes (OLs) in the central nervous system (CNS) and Schwann cells (SCs) in the peripheral nervous system (PNS), generate myelin sheaths that insulate axons. After myelination is completed in adulthood, MGC functions independent from myelin are required to support axon survival, but the underlying mechanisms are still unclear. Dicer is a key enzyme that is responsible for generating functional micro-RNAs (miRNAs). Despite the importance of Dicer in initiating myelination, the role of Dicer in mature MGCs is still unclear. Here, Dicer was specifically deleted in mature MGCs in 2-month old mice (PLP-CreERT; Dicer fl/fl) by tamoxifen administration. Progressive motor dysfunction was observed in the Dicer conditional knockout mice, which displayed hind limb ataxia at 3 months post recombination that deteriorated into paralysis within 5 months. Massive axonal degeneration/atrophy in peripheral nerves was responsible for this phenomenon, but overt demyelination was not observed in either the CNS or PNS. In contrast to the PNS, signs of axonal degeneration were not observed in the CNS of these animals. We induced a Dicer deletion in oligodendroglia at postnatal day 5 in NG2-CreERT; Dicer fl/fl mice to evaluate whether Dicer expression in OLs is essential for axonal survival. Dicer deletion in oligodendroglia did not cause motor dysfunction at the age of 7 months. Neither axonal atrophy nor demyelination was observed in the CNS. Based on our results, Dicer expression in SCs is required to maintain axon integrity in adult PNS, and Dicer is dispensable for maintaining myelin sheaths in MGCs.
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Affiliation(s)
- Tao Li
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Jingjing Wang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Hongkai Wang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China.,Department of Orthopedics, The Secondary Affiliated Hospital, Guilin Medical University, Guangxi, 541100, China
| | - Yujian Yang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Shouyu Wang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Nanxin Huang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Fei Wang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Xing Gao
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Jianqin Niu
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Zhifang Li
- Department of Neurology, Affiliated Hospital of Academy of Military Medical Sciences, Beijing, 100071, China
| | - Feng Mei
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Lan Xiao
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
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24
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Sohn EJ, Park HT. MicroRNA Mediated Regulation of Schwann Cell Migration and Proliferation in Peripheral Nerve Injury. BIOMED RESEARCH INTERNATIONAL 2018; 2018:8198365. [PMID: 29854793 PMCID: PMC5952561 DOI: 10.1155/2018/8198365] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/26/2018] [Indexed: 11/17/2022]
Abstract
Schwann cells (SCs) contribute to nerve repair following injury; however, the underlying molecular mechanism is poorly understood. MicroRNAs (miRNAs), which are short noncoding RNAs, have been shown to play a role in neuronal disease. In this work, we show that miRNAs regulate the peripheral nerve system by modulating the migration and proliferation of SCs. Thus, miRNAs expressed in peripheral nerves may provide a potential therapeutic target for peripheral nerve injury or repair.
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Affiliation(s)
- Eun Jung Sohn
- Peripheral Neuropathy Research Center, Department of Physiology, College of Medicine, Dong-A University, Busan, Republic of Korea
| | - Hwan Tae Park
- Peripheral Neuropathy Research Center, Department of Physiology, College of Medicine, Dong-A University, Busan, Republic of Korea
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25
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Macrophage Depletion Ameliorates Peripheral Neuropathy in Aging Mice. J Neurosci 2018; 38:4610-4620. [PMID: 29712789 DOI: 10.1523/jneurosci.3030-17.2018] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 02/06/2018] [Accepted: 03/09/2018] [Indexed: 01/02/2023] Open
Abstract
Aging is known as a major risk factor for the structure and function of the nervous system. There is urgent need to overcome such deleterious effects of age-related neurodegeneration. Here we show that peripheral nerves of 24-month-old aging C57BL/6 mice of either sex show similar pathological alterations as nerves from aging human individuals, whereas 12-month-old adult mice lack such alterations. Specifically, nerve fibers showed demyelination, remyelination and axonal lesion. Moreover, in the aging mice, neuromuscular junctions showed features typical for dying-back neuropathies, as revealed by a decline of presynaptic markers, associated with α-bungarotoxin-positive postsynapses. In line with these observations were reduced muscle strengths. These alterations were accompanied by elevated numbers of endoneurial macrophages, partially comprising the features of phagocytosing macrophages. Comparable profiles of macrophages could be identified in peripheral nerve biopsies of aging persons. To determine the pathological impact of macrophages in aging mice, we selectively targeted the cells by applying an orally administered CSF-1R specific kinase (c-FMS) inhibitor. The 6-month-lasting treatment started before development of degenerative changes at 18 months and reduced macrophage numbers in mice by ∼70%, without side effects. Strikingly, nerve structure was ameliorated and muscle strength preserved. We show, for the first time, that age-related degenerative changes in peripheral nerves are driven by macrophages. These findings may pave the way for treating degeneration in the aging peripheral nervous system by targeting macrophages, leading to reduced weakness, improved mobility, and eventually increased quality of life in the elderly.SIGNIFICANCE STATEMENT Aging is a major risk factor for the structure and function of the nervous system. Here we show that peripheral nerves of 24-month-old aging mice show similar degenerative alterations as nerves from aging human individuals. Both in mice and humans, these alterations were accompanied by endoneurial macrophages. To determine the pathological impact of macrophages in aging mice, we selectively targeted the cells by blocking a cytokine receptor, essential for macrophage survival. The treatment strongly reduced macrophage numbers and substantially improved nerve structure and muscle strength. We show, for the first time, that age-related degenerative changes in peripheral nerves are driven by macrophages. These findings may be helpful for treatment weakness and reduced mobility in the elderly.
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Zhao L, Yuan Y, Li P, Pan J, Qin J, Liu Y, Zhang Y, Tian F, Yu B, Zhou S. miR-221-3p Inhibits Schwann Cell Myelination. Neuroscience 2018; 379:239-245. [PMID: 29577996 DOI: 10.1016/j.neuroscience.2018.03.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 12/14/2022]
Abstract
Following peripheral nerve injury, Schwann Cells (SCs) undergo dedifferentiation, proliferation, migration, and remyelination. Recent works demonstrated the importance of the short non-coding RNA (miRNAs) in SC dedifferentiation and remyelination after nerve injury. Previously, we found some miRNAs like miR-9, miR-221, miR-222 and miR-182 could regulate the proliferation and migration of SCs. Therefore, it is imperative to ask whether these miRNAs could regulate the myelination of SCs. Here we demonstrated that miR-221-3p could inhibit the myelination of SCs when co-cultured with dorsal root ganglion cells in vitro. In addition, NGF1-A binding protein 1 (Nab1) which was essential for SCs myelination could be downregulated by miR-221-3p. Suppressing the expression of Nab1 could reverse the promotion of miR-221-3p antagomir on SC myelination. The effects of miR-221-3p on SC myelination might be used to improve peripheral nerve regeneration, thus offering a new approach to peripheral nerve repair.
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Affiliation(s)
- Lili Zhao
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China; State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing, Jiangsu 210000, China
| | - Ying Yuan
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.
| | - Ping Li
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Jiacheng Pan
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Jing Qin
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Yisheng Liu
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Yu Zhang
- F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital, Harvard Medical School, 300 Longwood Anevue, Boston, MA 02115, USA
| | - Feng Tian
- F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital, Harvard Medical School, 300 Longwood Anevue, Boston, MA 02115, USA
| | - Bin Yu
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Songlin Zhou
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.
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Lin HP, Oksuz I, Svaren J, Awatramani R. Egr2-dependent microRNA-138 is dispensable for peripheral nerve myelination. Sci Rep 2018; 8:3817. [PMID: 29491350 PMCID: PMC5830491 DOI: 10.1038/s41598-018-22010-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 02/14/2018] [Indexed: 12/27/2022] Open
Abstract
Recent studies have elucidated the crucial role for microRNAs in peripheral nerve myelination by ablating components of the microRNA synthesis machinery. Few studies have focused on the role of individual microRNAs. To fill this gap, we focused this study on miR-138, which was shown to be drastically reduced in Dicer1 and Dgcr8 knockout mice with hypomyelinating phenotypes and to potentially target the negative regulators of Schwann cell differentiation. Here, we show that of two miR-138 encoding loci, mir-138-1 is the predominant locus transcribed in Schwann cells. mir-138-1 is transcriptionally upregulated during myelination and downregulated upon nerve injury. EGR2 is required for mir-138-1 transcription during development, and both SOX10 and EGR2 bind to an active enhancer near the mir-138-1 locus. Based on expression analyses, we hypothesized that miR-138 facilitates the transition between undifferentiated Schwann cells and myelinating Schwann cells. However, in conditional knockouts, we could not detect significant changes in Schwann cell proliferation, cell cycle exit, or myelination. Overall, our results demonstrate that miR-138 is an Egr2-dependent microRNA but is dispensable for Schwann cell myelination.
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Affiliation(s)
- Hsin-Pin Lin
- Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Idil Oksuz
- Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - John Svaren
- Waisman Center and Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Rajeshwar Awatramani
- Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
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Novel miR-sc4 regulates the proliferation and migration of Schwann cells by targeting Cdk5r1. Mol Cell Biochem 2018; 447:209-215. [DOI: 10.1007/s11010-018-3305-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/25/2018] [Indexed: 12/22/2022]
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Li WY, Zhang WT, Cheng YX, Liu YC, Zhai FG, Sun P, Li HT, Deng LX, Zhu XF, Wang Y. Inhibition of KLF7-Targeting MicroRNA 146b Promotes Sciatic Nerve Regeneration. Neurosci Bull 2018; 34:419-437. [PMID: 29356943 DOI: 10.1007/s12264-018-0206-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 10/28/2017] [Indexed: 12/12/2022] Open
Abstract
A previous study has indicated that Krüppel-like factor 7 (KLF7), a transcription factor that stimulates Schwann cell (SC) proliferation and axonal regeneration after peripheral nerve injury, is a promising therapeutic transcription factor in nerve injury. We aimed to identify whether inhibition of microRNA-146b (miR-146b) affected SC proliferation, migration, and myelinated axon regeneration following sciatic nerve injury by regulating its direct target KLF7. SCs were transfected with miRNA lentivirus, miRNA inhibitor lentivirus, or KLF7 siRNA lentivirus in vitro. The expression of miR146b and KLF7, as well as SC proliferation and migration, were subsequently evaluated. In vivo, an acellular nerve allograft (ANA) followed by injection of GFP control vector or a lentiviral vector encoding an miR-146b inhibitor was used to assess the repair potential in a model of sciatic nerve gap. miR-146b directly targeted KLF7 by binding to the 3'-UTR, suppressing KLF7. Up-regulation of miR-146b and KLF7 knockdown significantly reduced the proliferation and migration of SCs, whereas silencing miR-146b resulted in increased proliferation and migration. KLF7 protein was localized in SCs in which miR-146b was expressed in vivo. Similarly, 4 weeks after the ANA, anti-miR-146b increased KLF7 and its target gene nerve growth factor cascade, promoting axonal outgrowth. Closer analysis revealed improved nerve conduction and sciatic function index score, and enhanced expression of neurofilaments, P0 (anti-peripheral myelin), and myelinated axon regeneration. Our findings provide new insight into the regulation of KLF7 by miR-146b during peripheral nerve regeneration and suggest a potential therapeutic strategy for peripheral nerve injury.
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Affiliation(s)
- Wen-Yuan Li
- Department of Anatomy, Mudanjiang College of Medicine, Mudanjiang, 157011, China
| | - Wei-Ting Zhang
- The Affiliated Hongqi Hospital, Mudanjiang College of Medicine, Mudanjiang, 157011, China
| | - Yong-Xia Cheng
- Department of Pathology, Mudanjiang College of Medicine, Mudanjiang, 157011, China
| | - Yan-Cui Liu
- Department of Anatomy, Mudanjiang College of Medicine, Mudanjiang, 157011, China
| | - Feng-Guo Zhai
- Department of Pharmacy, Mudanjiang College of Medicine, Mudanjiang, 157011, China
| | - Ping Sun
- Department of Anatomy, Mudanjiang College of Medicine, Mudanjiang, 157011, China
| | - Hui-Ting Li
- The Affiliated Hongqi Hospital, Mudanjiang College of Medicine, Mudanjiang, 157011, China
| | - Ling-Xiao Deng
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Xiao-Feng Zhu
- Department of Anatomy, Mudanjiang College of Medicine, Mudanjiang, 157011, China.
| | - Ying Wang
- Department of Anatomy, Mudanjiang College of Medicine, Mudanjiang, 157011, China.
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Llorens F, Thüne K, Martí E, Kanata E, Dafou D, Díaz-Lucena D, Vivancos A, Shomroni O, Zafar S, Schmitz M, Michel U, Fernández-Borges N, Andréoletti O, del Río JA, Díez J, Fischer A, Bonn S, Sklaviadis T, Torres JM, Ferrer I, Zerr I. Regional and subtype-dependent miRNA signatures in sporadic Creutzfeldt-Jakob disease are accompanied by alterations in miRNA silencing machinery and biogenesis. PLoS Pathog 2018; 14:e1006802. [PMID: 29357384 PMCID: PMC5794191 DOI: 10.1371/journal.ppat.1006802] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 02/01/2018] [Accepted: 12/11/2017] [Indexed: 12/14/2022] Open
Abstract
Increasing evidence indicates that microRNAs (miRNAs) are contributing factors to neurodegeneration. Alterations in miRNA signatures have been reported in several neurodegenerative dementias, but data in prion diseases are restricted to ex vivo and animal models. The present study identified significant miRNA expression pattern alterations in the frontal cortex and cerebellum of sporadic Creutzfeldt-Jakob disease (sCJD) patients. These changes display a highly regional and disease subtype-dependent regulation that correlates with brain pathology. We demonstrate that selected miRNAs are enriched in sCJD isolated Argonaute(Ago)-binding complexes in disease, indicating their incorporation into RNA-induced silencing complexes, and further suggesting their contribution to disease-associated gene expression changes. Alterations in the miRNA-mRNA regulatory machinery and perturbed levels of miRNA biogenesis key components in sCJD brain samples reported here further implicate miRNAs in sCJD gene expression (de)regulation. We also show that a subset of sCJD-altered miRNAs are commonly changed in Alzheimer's disease, dementia with Lewy bodies and fatal familial insomnia, suggesting potential common mechanisms underlying these neurodegenerative processes. Additionally, we report no correlation between brain and cerebrospinal fluid (CSF) miRNA-profiles in sCJD, indicating that CSF-miRNA profiles do not faithfully mirror miRNA alterations detected in brain tissue of human prion diseases. Finally, utilizing a sCJD MM1 mouse model, we analyzed the miRNA deregulation patterns observed in sCJD in a temporal manner. While fourteen sCJD-related miRNAs were validated at clinical stages, only two of those were changed at early symptomatic phase, suggesting that the miRNAs altered in sCJD may contribute to later pathogenic processes. Altogether, the present work identifies alterations in the miRNA network, biogenesis and miRNA-mRNA silencing machinery in sCJD, whereby contributions to disease mechanisms deserve further investigation.
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Affiliation(s)
- Franc Llorens
- Department of Neurology, University Medical School, Göttingen, Germany
- Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Katrin Thüne
- Department of Neurology, University Medical School, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Translational Studies and Biomarkers, Göttingen, Germany
| | | | - Eirini Kanata
- Prion Diseases Research Group, School of Health Sciences, Department Of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Dimitra Dafou
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Daniela Díaz-Lucena
- Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Ana Vivancos
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Orr Shomroni
- German Center for Neurodegenerative Diseases (DZNE), Computational Systems Biology, Göttingen, Germany
| | - Saima Zafar
- Department of Neurology, University Medical School, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Translational Studies and Biomarkers, Göttingen, Germany
| | - Matthias Schmitz
- Department of Neurology, University Medical School, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Translational Studies and Biomarkers, Göttingen, Germany
| | - Uwe Michel
- Department of Neurology, University Medical School, Göttingen, Germany
| | | | - Olivier Andréoletti
- Institut National de la Recherche Agronomique/Ecole Nationale Vétérinaire, Toulouse, France
| | - José Antonio del Río
- Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
- Molecular and Cellular Neurobiotechnology, Catalonian Institute for Bioengineering (IBEC), Parc Científic de Barcelona, Barcelona, Spain
- Department of Cell Biology, University of Barcelona, Barcelona, Spain
| | - Juana Díez
- Molecular Virology group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Andre Fischer
- German Center for Neurodegenerative Diseases (DZNE), Epigenetics and Systems Medicine in Neurodegenerative Diseases, Göttingen, Germany
| | - Stefan Bonn
- German Center for Neurodegenerative Diseases (DZNE), Computational Systems Biology, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany
- Center for Molecular Neurobiology University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Theodoros Sklaviadis
- Prion Diseases Research Group, School of Health Sciences, Department Of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Juan Maria Torres
- Centro de Investigación en Sanidad Animal (CISA-INIA), Madrid, Spain
| | - Isidre Ferrer
- Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
- Senior consultant, Bellvitge University Hospital-IDIBELL, Department of Pathology and Experimental Therapeutics, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain
| | - Inga Zerr
- Department of Neurology, University Medical School, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Translational Studies and Biomarkers, Göttingen, Germany
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31
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Ghibaudi M, Boido M, Vercelli A. Functional integration of complex miRNA networks in central and peripheral lesion and axonal regeneration. Prog Neurobiol 2017; 158:69-93. [PMID: 28779869 DOI: 10.1016/j.pneurobio.2017.07.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 07/24/2017] [Accepted: 07/28/2017] [Indexed: 01/06/2023]
Abstract
New players are emerging in the game of peripheral and central nervous system injury since their physiopathological mechanisms remain partially elusive. These mechanisms are characterized by several molecules whose activation and/or modification following a trauma is often controlled at transcriptional level. In this scenario, microRNAs (miRNAs/miRs) have been identified as main actors in coordinating important molecular pathways in nerve or spinal cord injury (SCI). miRNAs are small non-coding RNAs whose functionality at network level is now emerging as a new level of complexity. Indeed they can act as an organized network to provide a precise control of several biological processes. Here we describe the functional synergy of some miRNAs in case of SCI and peripheral damage. In particular we show how several small RNAs can cooperate in influencing simultaneously the molecular pathways orchestrating axon regeneration, inflammation, apoptosis and remyelination. We report about the networks for which miRNA-target bindings have been experimentally demonstrated or inferred based on target prediction data: in both cases, the connection between one miRNA and its downstream pathway is derived from a validated observation or is predicted from the literature. Hence, we discuss the importance of miRNAs in some pathological processes focusing on their functional structure as participating in a cooperative and/or convergence network.
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Affiliation(s)
- M Ghibaudi
- Department of Neuroscience "Rita Levi Montalcini", Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Italian Institute of Neuroscience, Italy.
| | - M Boido
- Department of Neuroscience "Rita Levi Montalcini", Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Italian Institute of Neuroscience, Italy
| | - A Vercelli
- Department of Neuroscience "Rita Levi Montalcini", Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Italian Institute of Neuroscience, Italy
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Zhang X, Gong X, Qiu J, Zhang Y, Gong F. MicroRNA-210 contributes to peripheral nerve regeneration through promoting the proliferation and migration of Schwann cells. Exp Ther Med 2017; 14:2809-2816. [PMID: 28912843 PMCID: PMC5585723 DOI: 10.3892/etm.2017.4869] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 03/31/2017] [Indexed: 12/31/2022] Open
Abstract
Peripheral nerve injury impacts the daily life of affected individuals. MicroRNA (miR)-210 is a multifunctional miR and has effects on the proliferation, migration and differentiation of cells. However, whether miR-210 has effects on peripheral nerve regeneration has remained elusive. In the present study, the miR-210 levels in a rat model of sciatic nerve injury were evaluated by reverse-transcription quantitative PCR and the effects of miR-210 on the proliferation and migration of Schwann cells were explored. Elevated miR-210 levels were discovered in the sciatic nerve injury rat model. miR-210 mimics were found to promote the proliferation and migration of Schwann cells, while miR-210 inhibitor was found to inhibit the proliferation and migration of Schwann cells. Further study showed that miR-210 had effects on the expression of growth-associated protein-43, myelin-associated glycoprotein and myelin basic protein. These results showed that miR-210 had effects on the proliferation and migration of Schwann cells and may be involved in the peripheral nerve regeneration.
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Affiliation(s)
- Xiaona Zhang
- Department of Anesthesiology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Xu Gong
- Department of Hand and Foot Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jinpeng Qiu
- Department of Anesthesiology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yang Zhang
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Fengyan Gong
- Department of Gynaecology and Obstetrics, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
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Comparison of DNA Methylation in Schwann Cells before and after Peripheral Nerve Injury in Rats. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5393268. [PMID: 28459064 PMCID: PMC5385226 DOI: 10.1155/2017/5393268] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/23/2017] [Accepted: 03/08/2017] [Indexed: 01/13/2023]
Abstract
This study aims to find the difference of genomewide DNA methylation in Schwann cells (SCs) before and after peripheral nerve system (PNS) injury by Methylated DNA Immunoprecipitation Sequencing (MeDIP-Seq) and seek meaningful differentially methylated genes related to repairment of injured PNS. SCs harvested from sciatic nerve were named as activated Schwann cells (ASCs), and the ones harvested from brachial plexus were named as normal Schwann cells (NSCs). Genomic DNA of ASCs and NSCs were isolated and MeDIP-Seq was conducted. Differentially methylated genes and regions were discovered and analyzed by bioinformatic methods. MeDIP-Seq analysis showed methylation differences were identified between ASCs and NSCs. The distribution of differentially methylated regions (DMRs) peaks in different components of genome was mainly located in distal intergenic regions. GO and KEGG analysis of these methylated genes were also conducted. The expression patterns of hypermethylated genes (Dgcr8, Zeb2, Dixdc1, Sox2, and Shh) and hypomethylated genes (Gpr126, Birc2) detected by qRT-PCR were opposite to the MeDIP analysis data with significance (p < 0.05), which proved MeDIP analysis data were real and believable. Our data serve as a basis for understanding the injury-induced epigenetic changes in SCs and the foundation for further studies on repair of PNS injury.
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Grove M, Kim H, Santerre M, Krupka AJ, Han SB, Zhai J, Cho JY, Park R, Harris M, Kim S, Sawaya BE, Kang SH, Barbe MF, Cho SH, Lemay MA, Son YJ. YAP/TAZ initiate and maintain Schwann cell myelination. eLife 2017; 6:e20982. [PMID: 28124973 PMCID: PMC5287714 DOI: 10.7554/elife.20982] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 01/22/2017] [Indexed: 12/12/2022] Open
Abstract
Nuclear exclusion of the transcriptional regulators and potent oncoproteins, YAP/TAZ, is considered necessary for adult tissue homeostasis. Here we show that nuclear YAP/TAZ are essential regulators of peripheral nerve development and myelin maintenance. To proliferate, developing Schwann cells (SCs) require YAP/TAZ to enter S-phase and, without them, fail to generate sufficient SCs for timely axon sorting. To differentiate, SCs require YAP/TAZ to upregulate Krox20 and, without them, completely fail to myelinate, resulting in severe peripheral neuropathy. Remarkably, in adulthood, nuclear YAP/TAZ are selectively expressed by myelinating SCs, and conditional ablation results in severe peripheral demyelination and mouse death. YAP/TAZ regulate both developmental and adult myelination by driving TEAD1 to activate Krox20. Therefore, YAP/TAZ are crucial for SCs to myelinate developing nerve and to maintain myelinated nerve in adulthood. Our study also provides a new insight into the role of nuclear YAP/TAZ in homeostatic maintenance of an adult tissue.
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Affiliation(s)
- Matthew Grove
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Hyukmin Kim
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Maryline Santerre
- FELS Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Alexander J Krupka
- Department of Bioengineering, Temple University, Philadelphia, United States
| | - Seung Baek Han
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Jinbin Zhai
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Jennifer Y Cho
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Raehee Park
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Michele Harris
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Seonhee Kim
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Bassel E Sawaya
- FELS Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Shin H Kang
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Mary F Barbe
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Seo-Hee Cho
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
| | - Michel A Lemay
- Department of Bioengineering, Temple University, Philadelphia, United States
| | - Young-Jin Son
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, United States
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35
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Yi S, Wang QH, Zhao LL, Qin J, Wang YX, Yu B, Zhou SL. miR-30c promotes Schwann cell remyelination following peripheral nerve injury. Neural Regen Res 2017; 12:1708-1715. [PMID: 29171437 PMCID: PMC5696853 DOI: 10.4103/1673-5374.217351] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Differential expression of miRNAs occurs in injured proximal nerve stumps and includes miRNAs that are firstly down-regulated and then gradually up-regulated following nerve injury. These miRNAs might be related to a Schwann cell phenotypic switch. miR-30c, as a member of this group, was further investigated in the current study. Sprague-Dawley rats underwent sciatic nerve transection and proximal nerve stumps were collected at 1, 4, 7, 14, 21, and 28 days post injury for analysis. Following sciatic nerve injury, miR-30c was down-regulated, reaching a minimum on day 4, and was then upregulated to normal levels. Schwann cells were isolated from neonatal rat sciatic nerve stumps, then transfected with miR-30c agomir and co-cultured in vitro with dorsal root ganglia. The enhanced expression of miR-30c robustly increased the amount of myelin-associated protein in the co-cultured dorsal root ganglia and Schwann cells. We then modeled sciatic nerve crush injury in vivo in Sprague-Dawley rats and tested the effect of perineural injection of miR-30c agomir on myelin sheath regeneration. Fourteen days after surgery, sciatic nerve stumps were harvested and subjected to immunohistochemistry, western blot analysis, and transmission electron microscopy. The direct injection of miR-30c stimulated the formation of myelin sheath, thus contributing to peripheral nerve regeneration. Overall, our findings indicate that miR-30c can promote Schwann cell myelination following peripheral nerve injury. The functional study of miR-30c will benefit the discovery of new therapeutic targets and the development of new treatment strategies for peripheral nerve regeneration.
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Affiliation(s)
- Sheng Yi
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Qi-Hui Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Li-Li Zhao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Jing Qin
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Ya-Xian Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Bin Yu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Song-Lin Zhou
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
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Potential Mechanism of Neurite Outgrowth Enhanced by Electrical Stimulation: Involvement of MicroRNA-363-5p Targeting DCLK1 Expression in Rat. Neurochem Res 2016; 42:513-525. [DOI: 10.1007/s11064-016-2100-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 10/27/2016] [Accepted: 11/02/2016] [Indexed: 01/25/2023]
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Akt Regulates Axon Wrapping and Myelin Sheath Thickness in the PNS. J Neurosci 2016; 36:4506-21. [PMID: 27098694 DOI: 10.1523/jneurosci.3521-15.2016] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/02/2016] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED The signaling pathways that regulate myelination in the PNS remain poorly understood. Phosphatidylinositol-4,5-bisphosphate 3-kinase 1A, activated in Schwann cells by neuregulin and the extracellular matrix, has an essential role in the early events of myelination. Akt/PKB, a key effector of phosphatidylinositol-4,5-bisphosphate 3-kinase 1A, was previously implicated in CNS, but not PNS myelination. Here we demonstrate that Akt plays a crucial role in axon ensheathment and in the regulation of myelin sheath thickness in the PNS. Pharmacological inhibition of Akt in DRG neuron-Schwann cell cocultures dramatically decreased MBP and P0 levels and myelin sheath formation without affecting expression of Krox20/Egr2, a key transcriptional regulator of myelination. Conversely, expression of an activated form of Akt in purified Schwann cells increased expression of myelin proteins, but not Krox20/Egr2, and the levels of activated Rac1. Transgenic mice expressing a membrane-targeted, activated form of Akt under control of the 2',3'-cyclic nucleotide 3'-phosphodiesterase promoter, exhibited thicker PNS and CNS myelin sheaths, and PNS myelin abnormalities, such as tomacula and myelin infoldings/outfoldings, centered around the paranodes and Schmidt Lanterman incisures. These effects were corrected by rapamycin treatmentin vivo Importantly, Akt activity in the transgenic mice did not induce myelination of nonmyelinating Schwann cells in the sympathetic trunk or Remak fibers of the dorsal roots, although, in those structures, they wrapped membranes redundantly around axons. Together, our data indicate that Akt is crucial for PNS myelination driving axonal wrapping by unmyelinated and myelinated Schwann cells and enhancing myelin protein synthesis in myelinating Schwann cells. SIGNIFICANCE STATEMENT Although the role of the key serine/threonine kinase Akt in promoting CNS myelination has been demonstrated, its role in the PNS has not been established and remains uncertain. This work reveals that Akt controls several key steps of the PNS myelination. First, its activity promotes membrane production and axonal wrapping independent of a transcriptional effect. In myelinated axons, it also enhances myelin thickness through the mTOR pathway. Finally, sustained Akt activation in Schwann cells leads to hypermyelination/dysmyelination, mimicking some features present in neuropathies, such as hereditary neuropathy with liability to pressure palsies or demyelinating forms of Charcot-Marie-Tooth disease. Together, these data demonstrate the role of Akt in regulatory mechanisms underlying axonal wrapping and myelination in the PNS.
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Qian TM, Zhao LL, Wang J, Li P, Qin J, Liu YS, Yu B, Ding F, Gu XS, Zhou SL. miR-148b-3p promotes migration of Schwann cells by targeting cullin-associated and neddylation-dissociated 1. Neural Regen Res 2016; 11:1001-5. [PMID: 27482232 PMCID: PMC4962562 DOI: 10.4103/1673-5374.184504] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
MicroRNAs (miRNAs) are small, non-coding RNAs that negatively adjust gene expression in multifarious biological processes. However, the regulatory effects of miRNAs on Schwann cells remain poorly understood. Previous microarray analysis results have shown that miRNA expression is altered following sciatic nerve transaction, thereby affecting proliferation and migration of Schwann cells. This study investigated whether miR-148b-3p could regulate migration of Schwann cells by directly targeting cullin-associated and neddylation-dissociated 1 (Cand1). Up-regulated expression of miR-148b-3p promoted Schwann cell migration, whereas silencing of miR-148b-3p inhibited Schwann cell migration in vitro. Further experiments confirmed that Cand1 was a direct target of miR-148b-3p, and Cand1 knockdown reversed suppression of the miR-148b-3p inhibitor on Schwann cell migration. These results suggested that miR-148b-3p promoted migration of Schwann cells by directly targeting Cand1 in vitro.
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Affiliation(s)
- Tian-Mei Qian
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Li-Li Zhao
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Jing Wang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Ping Li
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Jing Qin
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Yi-Sheng Liu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Bin Yu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Fei Ding
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Xiao-Song Gu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
| | - Song-Lin Zhou
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Co-innovation Center of Neuroregeneration, Nantong, Jiangsu Province, China
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Li S, Zhang R, Yuan Y, Yi S, Chen Q, Gong L, Liu J, Ding F, Cao Z, Gu X. MiR-340 Regulates Fibrinolysis and Axon Regrowth Following Sciatic Nerve Injury. Mol Neurobiol 2016; 54:4379-4389. [PMID: 27344331 DOI: 10.1007/s12035-016-9965-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/08/2016] [Indexed: 01/08/2023]
Abstract
After peripheral nerve injury, the degenerative debris and inflammatory alterations at the injury site may block the elongation of regenerating axons to reach target organs. Tissue plasminogen activator (tPA), a serine protease, has a capability of degrading matrix molecules and cell adhesions. In this study, we found that either tPA or miR-340 was differentially expressed in the injured nerve after sciatic nerve injury, and that the expressions of tPA and miR-340 were negatively correlated to each other. Moreover, miR-340 and tPA were co-localized in sciatic nerve. miR-340 regulated tPA through direct targeting of the 3'-UTR of tPA. Functionally, over- or under-expression of miR-340 reduced or augmented the fibrinolytic activity and migration ability of cultured Schwann cells as well as tPA secretion from the cells, respectively. In rats with sciatic nerve crush injury, dysregulation of the miR-340 expression in the injury site affected the cell debris removal and axonal regrowth. Obviously, unlike many previous studies that investigate the functional impact of miRNAs on peripheral nerve regeneration in the perspective of miRNA regulation of neural cell behaviors, the present study focused on miRNA regulation of debris clearance, thus updating our understanding of the regulatory roles of miRNAs in peripheral nerve regeneration.
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Affiliation(s)
- Shiying Li
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Ruirui Zhang
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Ying Yuan
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Sheng Yi
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Qianqian Chen
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Leilei Gong
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Jie Liu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Fei Ding
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Zheng Cao
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China.
| | - Xiaosong Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China.
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40
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Fiorenza A, Barco A. Role of Dicer and the miRNA system in neuronal plasticity and brain function. Neurobiol Learn Mem 2016; 135:3-12. [PMID: 27163737 DOI: 10.1016/j.nlm.2016.05.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 01/26/2023]
Abstract
MicroRNAs (miRNAs) are small regulatory non-coding RNAs that contribute to fine-tuning regulation of gene expression by mRNA destabilization and/or translational repression. Their abundance in the nervous system, their temporally and spatially regulated expression and their ability to respond in an activity-dependent manner make miRNAs ideal candidates for the regulation of complex processes in the brain, including neuronal plasticity, memory formation and neural development. The conditional ablation of the RNase III Dicer, which is essential for the maturation of most miRNAs, is a useful model to investigate the effect of the loss of the miRNA system, as a whole, in different tissues and cellular types. In this review, we first provide an overview of Dicer function and structure, and discuss outstanding questions concerning the role of miRNAs in the regulation of gene expression and neuronal function, to later focus on the insight derived from studies in which the genetic ablation of Dicer was used to determine the role of the miRNA system in the nervous system. In particular, we highlight the collective role of miRNAs fine-tuning plasticity-related gene expression and providing robustness to neuronal gene expression networks.
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Affiliation(s)
- Anna Fiorenza
- Instituto de Neurociencias (Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n, Sant Joan d'Alacant, 03550 Alicante, Spain
| | - Angel Barco
- Instituto de Neurociencias (Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n, Sant Joan d'Alacant, 03550 Alicante, Spain.
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41
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Birchmeier C, Bennett DLH. Neuregulin/ErbB Signaling in Developmental Myelin Formation and Nerve Repair. Curr Top Dev Biol 2016; 116:45-64. [PMID: 26970613 DOI: 10.1016/bs.ctdb.2015.11.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Myelin is essential for rapid and accurate conduction of electrical impulses by axons in the central and peripheral nervous system (PNS). Myelin is formed in the early postnatal period, and developmental myelination in the PNS depends on axonal signals provided by Nrg1/ErbB receptors. In addition, Nrg1 is required for effective nerve repair and remyelination in adulthood. We discuss here similarities and differences in Nrg1/ErbB functions in developmental myelination and remyelination after nerve injury.
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Affiliation(s)
- Carmen Birchmeier
- Developmental Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.
| | - David L H Bennett
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
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42
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Yi S, Wang S, Zhao Q, Yao C, Gu Y, Liu J, Gu X, Li S. miR-sc3, a Novel MicroRNA, Promotes Schwann Cell Proliferation and Migration by Targeting Astn1. Cell Transplant 2016; 25:973-82. [PMID: 26786955 DOI: 10.3727/096368916x690520] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
MicroRNAs (miRNAs, miRs) are small noncoding RNAs that regulate gene expression at the posttranscriptional level. We have previously identified a group of novel miRNAs in proximal sciatic nerve after sciatic nerve transection by Solexa sequencing, and miR-sc3 is a member of the group. In this study, we aimed to investigate the effects of miR-sc3 on phenotypic modulation of Schwann cells (SCs). miR-sc3 was highly expressed in the injured nerve after sciatic nerve transection. An increased and decreased expression of miR-sc3 promoted and reduced the proliferation and migration of primary SCs, respectively. miR-sc3 directly targeted astrotactin 1 (Astn1) and led to translational suppression of Astn1. There was an inverse association between the time-dependent expressions of miR-sc3 and Astn1 in proximal sciatic nerve after sciatic nerve transection. Overall, miR-sc3 affected SC proliferation and migration by targeting Astn1, thus playing the regulatory role in peripheral nerve regeneration.
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Affiliation(s)
- Sheng Yi
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
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43
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Gu Y, Chen C, Yi S, Wang S, Gong L, Liu J, Gu X, Zhao Q, Li S. miR-sc8 Inhibits Schwann Cell Proliferation and Migration by Targeting Egfr. PLoS One 2015; 10:e0145185. [PMID: 26683191 PMCID: PMC4686161 DOI: 10.1371/journal.pone.0145185] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/30/2015] [Indexed: 11/18/2022] Open
Abstract
MicroRNAs (miRNAs) negatively regulate the expression of target genes at the post-transcriptional level in diverse biological processes. We have previously identified a group of novel miRNAs in proximal nerve following rat sciatic nerve transection by Solexa sequencing. In this study, the biological function and action mode of miR-sc8, one of the above identified miRNAs, were investigated. An increased expression of miR-sc8 inhibited cell proliferation and migration of Schwann cells (SCs), and inversely, silencing of the miR-sc8 expression promoted cell proliferation and migration of SCs. The epidermal growth factor receptor (Egfr) was identified as the target gene of miR-sc8, which exerted negative regulation of Egfr by translational suppression. The temporal change profile of the miR-sc8 expression was negatively correlated with that of the Egfr expression in proximal nerve following sciatic nerve transection. Moreover, Knockdown of Egfr attenuated the promoting effects of miR-sc8 inhibitor on SC proliferation and migration. Overall, our data indicate that miR-sc8 affects phenotype modulation of SCs by targeting Egfr, providing further insights into the regulatory role of miRNAs in peripheral nerve regeneration.
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Affiliation(s)
- Yun Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, P. R. China
| | - Chu Chen
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, P. R. China
| | - Sheng Yi
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, P. R. China
| | - Shanshan Wang
- Department of Obstetrics and Gynecology, Affiliated Hospital of Nantong University, Nantong, Jiangsu, P. R. China
| | - Leilei Gong
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, P. R. China
| | - Jie Liu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, P. R. China
| | - Xiaosong Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, P. R. China
| | - Qing Zhao
- Key Laboratory of the People’s Liberation Army, Institute of Orthopaedics, Chinese PLA General Hospital, Beijing, P. R. China
- * E-mail: (QZ); (SL)
| | - Shiying Li
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, P. R. China
- * E-mail: (QZ); (SL)
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44
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The Lin28/let-7 axis is critical for myelination in the peripheral nervous system. Nat Commun 2015; 6:8584. [PMID: 26466203 PMCID: PMC4634210 DOI: 10.1038/ncomms9584] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 09/04/2015] [Indexed: 12/31/2022] Open
Abstract
MicroRNAs (miRNAs) are crucial regulators of myelination in the peripheral nervous system (PNS). However, the miRNAs species involved and the underlying mechanisms are largely unknown. We found that let-7 miRNAs are highly abundant during PNS myelination and that their levels are inversely correlated to the expression of lin28 homolog B (Lin28B), an antagonist of let-7 accumulation. Sustained expression of Lin28B and consequently reduced levels of let-7 miRNAs results in a failure of Schwann cell myelination in transgenic mouse models and in cell culture. Subsequent analyses revealed that let-7 miRNAs promote expression of the myelination-driving master transcription factor Krox20 (also known as Egr2) through suppression of myelination inhibitory Notch signalling. We conclude that the Lin28B/let-7 axis acts as a critical driver of PNS myelination, in particular by regulating myelination onset, identifying this pathway also as a potential therapeutic target in demyelinating diseases.
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45
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Yu B, Zhou S, Yi S, Gu X. The regulatory roles of non-coding RNAs in nerve injury and regeneration. Prog Neurobiol 2015; 134:122-39. [PMID: 26432164 DOI: 10.1016/j.pneurobio.2015.09.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 08/20/2015] [Accepted: 09/05/2015] [Indexed: 12/16/2022]
Abstract
Non-coding RNAs (ncRNAs), especially microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have attracted much attention since their regulatory roles in diverse cell processes were recognized. Emerging studies demonstrate that many ncRNAs are differentially expressed after injury to the nervous system, significantly affecting nerve regeneration. In this review, we compile the miRNAs and lncRNAs that have been reported to be dysregulated following a variety of central and peripheral nerve injuries, including acquired brain injury, spinal cord injury, and peripheral nerve injury. We also list investigations on how these miRNAs and lncRNAs exert the regulatory actions in neurodegenerative and neuroregenerative processes through different mechanisms involving their interaction with target coding genes. We believe that comprehension of the expression profiles and the possible functions of ncRNAs during the processes of nerve injury and regeneration will help understand the molecular mechanisms responsible for post-nerve-injury changes, and may contribute to the potential use of ncRNAs as a diagnostic marker and therapeutic target for nerve injury.
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Affiliation(s)
- Bin Yu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
| | - Songlin Zhou
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
| | - Sheng Yi
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
| | - Xiaosong Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China.
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46
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Stolt CC, Wegner M. Schwann cells and their transcriptional network: Evolution of key regulators of peripheral myelination. Brain Res 2015; 1641:101-110. [PMID: 26423937 DOI: 10.1016/j.brainres.2015.09.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 09/18/2015] [Accepted: 09/20/2015] [Indexed: 11/29/2022]
Abstract
As derivatives of the neural crest, Schwann cells represent a vertebrate invention. Their development and differentiation is under control of a newly constructed, vertebrate-specific regulatory network that contains Sox10, Oct6 and Krox20 as cornerstones and central regulators of peripheral myelination. In this review, we discuss the function and relationship of these transcription factors among each other and in the context of their regulatory network, and present ideas of how neofunctionalization may have helped to recruit them to their novel task in Schwann cells. This article is part of a Special Issue entitled SI: Myelin Evolution.
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Affiliation(s)
- C Claus Stolt
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054 Erlangen, Germany.
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47
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SncRNA715 Inhibits Schwann Cell Myelin Basic Protein Synthesis. PLoS One 2015; 10:e0136900. [PMID: 26317513 PMCID: PMC4552632 DOI: 10.1371/journal.pone.0136900] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/10/2015] [Indexed: 01/03/2023] Open
Abstract
Myelin basic proteins (MBP) are major constituents of the myelin sheath in the central nervous system (CNS) and the peripheral nervous system (PNS). In the CNS Mbp translation occurs locally at the axon-glial contact site in a neuronal activity-dependent manner. Recently we identified the small non-coding RNA 715 (sncRNA715) as a key inhibitor of Mbp translation during transport in oligodendrocytes. Mbp mRNA localization in Schwann cells has been observed, but has not been investigated in much detail. Here we could confirm translational repression of Mbp mRNA in Schwann cells. We show that sncRNA715 is expressed and its levels correlate inversely with MBP in cultured Schwann cells and in the sciatic nerve in vivo. Furthermore we could reduce MBP protein levels in cultured Schwann cells by increasing the levels of the inhibitory sncRNA715. Our findings suggest similarities in sncRNA715-mediated translational repression of Mbp mRNA in oligodendrocytes and Schwann cells.
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48
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Lin HP, Oksuz I, Hurley E, Wrabetz L, Awatramani R. Microprocessor complex subunit DiGeorge syndrome critical region gene 8 (Dgcr8) is required for schwann cell myelination and myelin maintenance. J Biol Chem 2015; 290:24294-307. [PMID: 26272614 DOI: 10.1074/jbc.m115.636407] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Indexed: 01/25/2023] Open
Abstract
We investigated the role of a key component of the Microprocessor complex, DGCR8, in the regulation of myelin formation and maintenance. We found that conditionally ablating Dgcr8 in Schwann cells (SCs) during development results in an arrest of SC differentiation. Dgcr8 conditional knock-out (cKO) SCs fail to form 1:1 relationships with axons or, having achieved this, fail to form myelin sheaths. The expression of genes normally found in immature SCs, such as sex-determining region Y-box 2 (Sox2), is increased in Dgcr8 cKO SCs, whereas the expression of myelin-related genes, including the master regulatory transcription factor early growth response 2 (Egr2), is decreased. Additionally, expression of a novel gene expression program involving sonic hedgehog (Shh), activated de novo in injured nerves, is elevated in Dgcr8 cKOs but not in Egr2 null mice, a model of SC differentiation arrest, suggesting that the injury-related gene expression program in Dgcr8 cKOs cannot be attributed to differentiation arrest. Inducible ablation of Dgcr8 in adult SCs results in gene expression changes similar to those found in cKOs, including an increase in the expression of Sox2 and Shh. Analyses of these nerves mainly reveal normal myelin thickness and axon size distribution but some dedifferentiated SCs and increased macrophage infiltration. Together our data suggest that Dgcr8 is responsible for modulation of gene expression programs underlying myelin formation and maintenance as well as suppression of an injury-related gene expression program.
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Affiliation(s)
- Hsin-Pin Lin
- From the Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and
| | - Idil Oksuz
- From the Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and
| | - Edward Hurley
- Hunter James Kelly Research Institute, University at Buffalo, State University of New York, Buffalo, New York 14203
| | - Lawrence Wrabetz
- Hunter James Kelly Research Institute, University at Buffalo, State University of New York, Buffalo, New York 14203
| | - Rajeshwar Awatramani
- From the Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and
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Monk KR, Feltri ML, Taveggia C. New insights on Schwann cell development. Glia 2015; 63:1376-93. [PMID: 25921593 PMCID: PMC4470834 DOI: 10.1002/glia.22852] [Citation(s) in RCA: 179] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/13/2015] [Indexed: 12/11/2022]
Abstract
In the peripheral nervous system, Schwann cells are glial cells that are in intimate contact with axons throughout development. Schwann cells generate the insulating myelin sheath and provide vital trophic support to the neurons that they ensheathe. Schwann cell precursors arise from neural crest progenitor cells, and a highly ordered developmental sequence controls the progression of these cells to become mature myelinating or nonmyelinating Schwann cells. Here, we discuss both seminal discoveries and recent advances in our understanding of the molecular mechanisms that drive Schwann cell development and myelination with a focus on cell-cell and cell-matrix signaling events.
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Affiliation(s)
- Kelly R Monk
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri
| | - M Laura Feltri
- Department of Biochemistry and Neurology, Hunter James Kelly Research Institute, University at Buffalo, State University of New York, Buffalo, New York
| | - Carla Taveggia
- Division of Neuroscience and INSPE, San Raffaele Scientific Institute, Milan, Italy
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50
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Abstract
Myelinated nerve fibers are essential for the rapid propagation of action potentials by saltatory conduction. They form as the result of reciprocal interactions between axons and Schwann cells. Extrinsic signals from the axon, and the extracellular matrix, drive Schwann cells to adopt a myelinating fate, whereas myelination reorganizes the axon for its role in conduction and is essential for its integrity. Here, we review our current understanding of the development, molecular organization, and function of myelinating Schwann cells. Recent findings into the extrinsic signals that drive Schwann cell myelination, their cognate receptors, and the downstream intracellular signaling pathways they activate will be described. Together, these studies provide important new insights into how these pathways converge to activate the transcriptional cascade of myelination and remodel the actin cytoskeleton that is critical for morphogenesis of the myelin sheath.
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Affiliation(s)
- James L Salzer
- Department of Neuroscience and Physiology, New York University Neuroscience Institute, New York University School of Medicine, New York, New York 10016
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