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Wei C, Guo Y, Ci Z, Li M, Zhang Y, Zhou Y. Advances of Schwann cells in peripheral nerve regeneration: From mechanism to cell therapy. Biomed Pharmacother 2024; 175:116645. [PMID: 38729050 DOI: 10.1016/j.biopha.2024.116645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/18/2024] [Accepted: 04/24/2024] [Indexed: 05/12/2024] Open
Abstract
Peripheral nerve injuries (PNIs) frequently occur due to various factors, including mechanical trauma such as accidents or tool-related incidents, as well as complications arising from diseases like tumor resection. These injuries frequently result in persistent numbness, impaired motor and sensory functions, neuropathic pain, or even paralysis, which can impose a significant financial burden on patients due to outcomes that often fall short of expectations. The most frequently employed clinical treatment for PNIs involves either direct sutures of the severed ends or bridging the proximal and distal stumps using autologous nerve grafts. However, autologous nerve transplantation may result in sensory and motor functional loss at the donor site, as well as neuroma formation and scarring. Transplantation of Schwann cells/Schwann cell-like cells has emerged as a promising cellular therapy to reconstruct the microenvironment and facilitate peripheral nerve regeneration. In this review, we summarize the role of Schwann cells and recent advances in Schwann cell therapy in peripheral nerve regeneration. We summarize current techniques used in cell therapy, including cell injection, 3D-printed scaffolds for cell delivery, cell encapsulation techniques, as well as the cell types employed in experiments, experimental models, and research findings. At the end of the paper, we summarize the challenges and advantages of various cells (including ESCs, iPSCs, and BMSCs) in clinical cell therapy. Our goal is to provide the theoretical and experimental basis for future treatments targeting peripheral nerves, highlighting the potential of cell therapy and tissue engineering as invaluable resources for promoting nerve regeneration.
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Affiliation(s)
- Chuqiao Wei
- Department of Oral Implantology, Hospital of Stomatology, Jilin University, Changchun, China; Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun, China
| | - Yuanxin Guo
- Department of Oral Implantology, Hospital of Stomatology, Jilin University, Changchun, China; Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun, China
| | - Zhen Ci
- Department of Oral Implantology, Hospital of Stomatology, Jilin University, Changchun, China; Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun, China
| | - Mucong Li
- Department of Oral Implantology, Hospital of Stomatology, Jilin University, Changchun, China; Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun, China
| | - Yidi Zhang
- Department of Oral Implantology, Hospital of Stomatology, Jilin University, Changchun, China; Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun, China.
| | - Yanmin Zhou
- Department of Oral Implantology, Hospital of Stomatology, Jilin University, Changchun, China; Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun, China.
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Yetkin-Arik B, Jansen SA, Varderidou-Minasian S, Westendorp B, Skarp KP, Altelaar M, Lindemans CA, Lorenowicz MJ. Mesenchymal stromal/stem cells promote intestinal epithelium regeneration after chemotherapy-induced damage. Stem Cell Res Ther 2024; 15:125. [PMID: 38679715 PMCID: PMC11057078 DOI: 10.1186/s13287-024-03738-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 04/20/2024] [Indexed: 05/01/2024] Open
Abstract
BACKGROUND Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for leukemia and a range of non-malignant disorders. The success of the therapy is hampered by occurrence of acute graft-versus-host disease (aGvHD); an inflammatory response damaging recipient organs, with gut, liver, and skin being the most susceptible. Intestinal GvHD injury is often a life-threatening complication in patients unresponsive to steroid treatment. Allogeneic mesenchymal stromal/stem cell (MSC) infusions are a promising potential treatment for steroid-resistant aGvHD. Data from our institution and others demonstrate rescue of approximately 40-50% of aGvHD patients with MSCs in Phase I, II studies and minor side effects. Although promising, better understanding of MSC mode of action and patient response to MSC-based therapy is essential to improve this lifesaving treatment. METHODS Single cell human small intestine organoids were embedded in Matrigel, grown for 5 days and treated with busulfan for 48 h. Organoids damaged by treatment with busulfan or control organoids were co-cultured with 5000, 10,000, and 50,000 MSCs for 24 h, 48 h or 7 days and the analyses such as surface area determination, proliferation and apoptosis assessment, RNA sequencing and proteomics were performed. RESULTS Here, we developed a 3D co-culture model of human small intestinal organoids and MSCs, which allows to study the regenerative effects of MSCs on intestinal epithelium in a more physiologically relevant setting than existing in vitro systems. Using this model we mimicked chemotherapy-mediated damage of the intestinal epithelium. The treatment with busulfan, the chemotherapeutic commonly used as conditioning regiment before the HSCT, affected pathways regulating epithelial to mesenchymal transition, proliferation, and apoptosis in small intestinal organoids, as shown by transcriptomic and proteomic analysis. The co-culture of busulfan-treated intestinal organoids with MSCs reversed the effects of busulfan on the transcriptome and proteome of intestinal epithelium, which we also confirmed by functional evaluation of proliferation and apoptosis. CONCLUSIONS Collectively, we demonstrate that our in vitro co-culture system is a new valuable tool to facilitate the investigation of the molecular mechanisms behind the therapeutic effects of MSCs on damaged intestinal epithelium. This could benefit further optimization of the use of MSCs in HSCT patients.
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Affiliation(s)
- B Yetkin-Arik
- Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
- Regenerative Medicine Center, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
- Centre for Living Technologies, Alliance TU/E, WUR, UU, UMC Utrecht, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - S A Jansen
- Regenerative Medicine Center, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
- Division of Pediatrics, University Medical Center Utrecht, Utrecht, The Netherlands
- Pediatric Stem Cell Transplantation, Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - S Varderidou-Minasian
- Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
- Regenerative Medicine Center, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - B Westendorp
- Regenerative Medicine Center, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
- Division Cell Biology, Metabolism and Cancer, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - K-P Skarp
- Biomedical Primate Research Center, Lange Kleiweg 161, 2288 GJ, Rijswijk, The Netherlands
| | - M Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, and Utrecht Institute For Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - C A Lindemans
- Regenerative Medicine Center, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
- Division of Pediatrics, University Medical Center Utrecht, Utrecht, The Netherlands
- Pediatric Stem Cell Transplantation, Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - M J Lorenowicz
- Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands.
- Regenerative Medicine Center, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands.
- Biomedical Primate Research Center, Lange Kleiweg 161, 2288 GJ, Rijswijk, The Netherlands.
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Zhang WJ, Liu SC, Ming LG, Yu JW, Zuo C, Hu DX, Luo HL, Zhang Q. Potential role of Schwann cells in neuropathic pain. Eur J Pharmacol 2023; 956:175955. [PMID: 37541365 DOI: 10.1016/j.ejphar.2023.175955] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Neuropathic pain (NPP) is a common syndrome associated with most forms of disease, which poses a serious threat to human health. NPP may persist even after the nociceptive stimulation is eliminated, and treatment is extremely challenging in such cases. Schwann cells (SCs) form the myelin sheaths around neuronal axons and play a crucial role in neural information transmission. SCs can secrete trophic factors to nourish and protect axons, and can further secrete pain-related factors to induce pain. SCs may be activated by peripheral nerve injury, triggering the transformation of myelinated and non-myelinated SCs into cell phenotypes that specifically promote repair. These differentiated SCs provide necessary signals and spatial clues for survival, axonal regeneration, and nerve regeneration of damaged neurons. They can further change the microenvironment around the regions of nerve injury, and relieve the pain by repairing the injured nerve. Herein, we provide a comprehensive overview of the biological characteristics of SCs, discuss the relationship between SCs and nerve injury, and explore the potential mechanism of SCs and the occurrence of NPP. Moreover, we summarize the feasible strategies of SCs in the treatment of NPP, and attempt to elucidate the deficiencies and defects of SCs in the treatment of NPP.
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Affiliation(s)
- Wen-Jun Zhang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Si-Cheng Liu
- Department of Gastrointestinal surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Li-Guo Ming
- Department of Gastrointestinal surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Jian-Wen Yu
- Department of Gastrointestinal surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Cheng Zuo
- Department of Gastrointestinal surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Dong-Xia Hu
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Hong-Liang Luo
- Department of Gastrointestinal surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China.
| | - Qiao Zhang
- Orthopedics Department, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China.
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Fu J, Zhao L, Yang J, Chen H, Cao S, Jia H. An unconventional SNARE complex mediates exocytosis at the plasma membrane and vesicular fusion at the apical annuli in Toxoplasma gondii. PLoS Pathog 2023; 19:e1011288. [PMID: 36972314 PMCID: PMC10079086 DOI: 10.1371/journal.ppat.1011288] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 04/06/2023] [Accepted: 03/09/2023] [Indexed: 03/29/2023] Open
Abstract
Exocytosis is a key active process in cells by which proteins are released in bulk via the fusion of exocytic vesicles with the plasma membrane. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein-mediated vesicle fusion with the plasma membrane is essential in most exocytotic pathways. In mammalian cells, the vesicular fusion step of exocytosis is normally mediated by Syntaxin-1 (Stx1) and SNAP25 family proteins (SNAP25 and SNAP23). However, in Toxoplasma gondii, a model organism of Apicomplexa, the only SNAP25 family protein, with a SNAP29-like molecular structure, is involved in vesicular fusion at the apicoplast. Here, we reveal that an unconventional SNARE complex comprising TgStx1, TgStx20, and TgStx21 mediates vesicular fusion at the plasma membrane. This complex is essential for the exocytosis of surface proteins and vesicular fusion at the apical annuli in T. gondii.
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Affiliation(s)
- Jiawen Fu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Harbin, China
| | - Lin Zhao
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Harbin, China
| | - Juan Yang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Harbin, China
| | - Heming Chen
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Harbin, China
| | - Shinuo Cao
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Harbin, China
| | - Honglin Jia
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Harbin, China
- * E-mail:
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Chun YL, Eom WJ, Lee JH, Nguyen TNC, Park KH, Chung HJ, Seo H, Huh Y, Kim SH, Yeo SG, Park W, Bang G, Kim JY, Kim MS, Jeong NY, Jung J. Investigation of the Hydrogen Sulfide Signaling Pathway in Schwann Cells during Peripheral Nerve Degeneration: Multi-Omics Approaches. Antioxidants (Basel) 2022; 11:antiox11081606. [PMID: 36009325 PMCID: PMC9405209 DOI: 10.3390/antiox11081606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/09/2022] [Accepted: 08/16/2022] [Indexed: 11/30/2022] Open
Abstract
N-ethylmaleimide (NEM) inhibits peripheral nerve degeneration (PND) by targeting Schwann cells in a hydrogen sulfide (H2S)-pathway-dependent manner, but the underlying molecular and pharmacological mechanisms are unclear. We investigated the effect of NEM, an α,β-unsaturated carboxyl compound, on H2S signaling in in vitro- and ex vivo-dedifferentiated Schwann cells using global proteomics (LC-MS) and transcriptomics (whole-genome and small RNA-sequencing (RNA-seq)) methods. The multi-omics analyses identified several genes and proteins related to oxidative stress, such as Sod1, Gnao1, Stx4, Hmox2, Srxn1, and Edn1. The responses to oxidative stress were transcriptionally regulated by several transcription factors, such as Atf3, Fos, Rela, and Smad2. In a functional enrichment analysis, cell cycle, oxidative stress, and lipid/cholesterol metabolism were enriched, implicating H2S signaling in Schwann cell dedifferentiation, proliferation, and myelination. NEM-induced changes in the H2S signaling pathway affect oxidative stress, lipid metabolism, and the cell cycle in Schwann cells. Therefore, regulation of the H2S signaling pathway by NEM during PND could prevent Schwann cell demyelination, dedifferentiation, and proliferation.
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Affiliation(s)
- Yoo Lim Chun
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
- Department of Biomedical Science, Graduation School, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
- Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Seo-gu, Busan 49201, Korea
| | - Won-Joon Eom
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
- Department of Biomedical Science, Graduation School, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
| | - Jun Hyung Lee
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Dalseong-gu, Daegu 42988, Korea
| | - Thy N. C. Nguyen
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Dalseong-gu, Daegu 42988, Korea
| | - Ki-Hoon Park
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
- Department of Anesthesiology and Pain Medicine, College of Medicine, Kosin University, Seo-gu, Busan 49267, Korea
| | - Hyung-Joo Chung
- Department of Anesthesiology and Pain Medicine, College of Medicine, Kosin University, Seo-gu, Busan 49267, Korea
| | - Han Seo
- Department of Anesthesiology and Pain Medicine, College of Medicine, Kosin University, Seo-gu, Busan 49267, Korea
| | - Youngbuhm Huh
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
- Department of Biomedical Science, Graduation School, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
| | - Sang Hoon Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
| | - Seung Geun Yeo
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
| | - Wonseok Park
- Department of Orthopedic Surgery, Good Samsun Hospital, Sasang-gu, Busan, 47007, Korea
| | - Geul Bang
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang 28119, Korea
| | - Jin Young Kim
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang 28119, Korea
| | - Min-Sik Kim
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Dalseong-gu, Daegu 42988, Korea
- Correspondence: (M.-S.K.); (N.Y.J.); (J.J.)
| | - Na Young Jeong
- Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Seo-gu, Busan 49201, Korea
- Correspondence: (M.-S.K.); (N.Y.J.); (J.J.)
| | - Junyang Jung
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
- Department of Biomedical Science, Graduation School, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea
- Correspondence: (M.-S.K.); (N.Y.J.); (J.J.)
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Chang SJ, Hsu YT, Chen Y, Lin YY, Lara-Tejero M, Galan JE. Typhoid toxin sorting and exocytic transport from Salmonella Typhi-infected cells. eLife 2022; 11:e78561. [PMID: 35579416 PMCID: PMC9142146 DOI: 10.7554/elife.78561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/15/2022] [Indexed: 11/13/2022] Open
Abstract
Typhoid toxin is an essential virulence factor for Salmonella Typhi, the cause of typhoid fever in humans. This toxin has an unusual biology in that it is produced by Salmonella Typhi only when located within host cells. Once synthesized, the toxin is secreted to the lumen of the Salmonella-containing vacuole from where it is transported to the extracellular space by vesicle carrier intermediates. Here, we report the identification of the typhoid toxin sorting receptor and components of the cellular machinery that packages the toxin into vesicle carriers, and exports it to the extracellular space. We found that the cation-independent mannose-6-phosphate receptor serves as typhoid toxin sorting receptor and that the coat protein COPII and the GTPase Sar1 mediate its packaging into vesicle carriers. Formation of the typhoid toxin carriers requires the specific environment of the Salmonella Typhi-containing vacuole, which is determined by the activities of specific effectors of its type III protein secretion systems. We also found that Rab11B and its interacting protein Rip11 control the intracellular transport of the typhoid toxin carriers, and the SNARE proteins VAMP7, SNAP23, and Syntaxin 4 their fusion to the plasma membrane. Typhoid toxin's cooption of specific cellular machinery for its transport to the extracellular space illustrates the remarkable adaptation of an exotoxin to exert its function in the context of an intracellular pathogen.
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Affiliation(s)
- Shu-Jung Chang
- Department of Microbial Pathogenesis, Yale University School of MedicineNew HavenUnited States
- Graduate Institute of Microbiology, College of Medicine, National Taiwan UniversityTaipeiTaiwan
| | - Yu-Ting Hsu
- Graduate Institute of Microbiology, College of Medicine, National Taiwan UniversityTaipeiTaiwan
| | - Yun Chen
- Graduate Institute of Microbiology, College of Medicine, National Taiwan UniversityTaipeiTaiwan
| | - Yen-Yi Lin
- Graduate Institute of Microbiology, College of Medicine, National Taiwan UniversityTaipeiTaiwan
| | - Maria Lara-Tejero
- Department of Microbial Pathogenesis, Yale University School of MedicineNew HavenUnited States
| | - Jorge E Galan
- Department of Microbial Pathogenesis, Yale University School of MedicineNew HavenUnited States
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Abstract
Schwann cells are components of the peripheral nerve myelin sheath, which supports and nourishes axons. Upon injury of the trigeminal nerve, Schwann cells are activated and cause trigeminal neuralgia by engulfing the myelin sheath and secreting various neurotrophic factors. Further, Schwann cells can repair the damaged nerve and thus alleviate trigeminal neuralgia. Here, we briefly describe the development and activation of Schwann cells after nerve injury. Moreover, we expound on the occurrence, regulation, and treatment of trigeminal neuralgia; further, we point out the current research deficiencies and future research directions.
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Affiliation(s)
- Jia-Yi Liao
- Stomatology College of Nanchang University, Nanchang, China
| | - Tian-Hua Zhou
- Basic Medical School, Nanchang University, Nanchang, China
| | - Bao-Kang Chen
- First Clinical Medical College of Nanchang University, Nanchang, China
| | - Zeng-Xu Liu
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang, China
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8
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Hirano AA, Vuong HE, Kornmann HL, Schietroma C, Stella SL, Barnes S, Brecha NC. Vesicular Release of GABA by Mammalian Horizontal Cells Mediates Inhibitory Output to Photoreceptors. Front Cell Neurosci 2020; 14:600777. [PMID: 33335476 PMCID: PMC7735995 DOI: 10.3389/fncel.2020.600777] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/04/2020] [Indexed: 12/14/2022] Open
Abstract
Feedback inhibition by horizontal cells regulates rod and cone photoreceptor calcium channels that control their release of the neurotransmitter glutamate. This inhibition contributes to synaptic gain control and the formation of the center-surround antagonistic receptive fields passed on to all downstream neurons, which is important for contrast sensitivity and color opponency in vision. In contrast to the plasmalemmal GABA transporter found in non-mammalian horizontal cells, there is evidence that the mechanism by which mammalian horizontal cells inhibit photoreceptors involves the vesicular release of the inhibitory neurotransmitter GABA. Historically, inconsistent findings of GABA and its biosynthetic enzyme, L-glutamate decarboxylase (GAD) in horizontal cells, and the apparent lack of surround response block by GABAergic agents diminished support for GABA's role in feedback inhibition. However, the immunolocalization of the vesicular GABA transporter (VGAT) in the dendritic and axonal endings of horizontal cells that innervate photoreceptor terminals suggested GABA was released via vesicular exocytosis. To test the idea that GABA is released from vesicles, we localized GABA and GAD, multiple SNARE complex proteins, synaptic vesicle proteins, and Cav channels that mediate exocytosis to horizontal cell dendritic tips and axonal terminals. To address the perceived relative paucity of synaptic vesicles in horizontal cell endings, we used conical electron tomography on mouse and guinea pig retinas that revealed small, clear-core vesicles, along with a few clathrin-coated vesicles and endosomes in horizontal cell processes within photoreceptor terminals. Some small-diameter vesicles were adjacent to the plasma membrane and plasma membrane specializations. To assess vesicular release, a functional assay involving incubation of retinal slices in luminal VGAT-C antibodies demonstrated vesicles fused with the membrane in a depolarization- and calcium-dependent manner, and these labeled vesicles can fuse multiple times. Finally, targeted elimination of VGAT in horizontal cells resulted in a loss of tonic, autaptic GABA currents, and of inhibitory feedback modulation of the cone photoreceptor Cai, consistent with the elimination of GABA release from horizontal cell endings. These results in mammalian retina identify the central role of vesicular release of GABA from horizontal cells in the feedback inhibition of photoreceptors.
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Affiliation(s)
- Arlene A. Hirano
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Helen E. Vuong
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Helen L. Kornmann
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Cataldo Schietroma
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Salvatore L. Stella
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Steven Barnes
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Doheny Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Nicholas C. Brecha
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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The SNAP-25 Protein Family. Neuroscience 2019; 420:50-71. [DOI: 10.1016/j.neuroscience.2018.09.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/31/2018] [Accepted: 09/14/2018] [Indexed: 01/04/2023]
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10
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Gao D, Tang T, Zhu J, Tang Y, Sun H, Li S. CXCL12 has therapeutic value in facial nerve injury and promotes Schwann cells autophagy and migration via PI3K-AKT-mTOR signal pathway. Int J Biol Macromol 2018; 124:460-468. [PMID: 30391592 DOI: 10.1016/j.ijbiomac.2018.10.212] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/06/2018] [Accepted: 10/30/2018] [Indexed: 01/10/2023]
Abstract
Facial nerve injury is a clinically common disease accompanied by demyelination of damaged nerves. The remyelination of damaged nerves and the unsatisfactory function recovery are problems that have been plaguing people for a long time. The role that CXCL12 plays after facial nerve injury remains unknown. Our experiments found that the expression of CXCL12 was up-regulated in the early stage of facial nerve injury and decreased after two weeks. Further research found that CXCL12 had no effect on Schwann cells proliferation, apoptosis and cell cycle, while significantly promoted Schwann cells migration. Treatment with CXCL12 decreased the phosphorylation of PI3K, AKT and mTOR, but increased autophagy marker LC3II/I. The CXCL12-induced Schwann cells migration was significantly attenuated by inhibition of autophagy and activation of PI3K pathway through pretreatment with 3-MA and IGF-1 respectively, and this effect was enhanced by PI3K pathway inhibitor LY294002. Animal experiment also confirmed that CXCL12 could improve facial nerve function and myelin regeneration. The findings of this study indicate that CXCL12 can promote the migration of Schwann cells and potentially become a key molecule in the repair of facial nerve injury.
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Affiliation(s)
- Dekun Gao
- Department of Neurosurgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Tianchi Tang
- Department of Neurosurgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Jin Zhu
- Department of Neurosurgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Yinda Tang
- Department of Neurosurgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Hui Sun
- Department of Neurosurgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China.
| | - Shiting Li
- Department of Neurosurgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China.
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