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Novacescu D, Nesiu A, Bardan R, Latcu SC, Dema VF, Croitor A, Raica M, Cut TG, Walter J, Cumpanas AA. Rats, Neuregulins and Radical Prostatectomy: A Conceptual Overview. J Clin Med 2023; 12:jcm12062208. [PMID: 36983210 PMCID: PMC10051646 DOI: 10.3390/jcm12062208] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/06/2023] [Accepted: 03/10/2023] [Indexed: 03/14/2023] Open
Abstract
In the contemporary era of early detection, with mostly curative initial treatment for prostate cancer (PC), mortality rates have significantly diminished. In addition, mean age at initial PC diagnosis has decreased. Despite technical advancements, the probability of erectile function (EF) recovery post radical prostatectomy (RP) has not significantly changed throughout the last decade. Due to virtually unavoidable intraoperative cavernous nerve (CN) lesions and operations with younger patients, post-RP erectile dysfunction (ED) has now begun affecting these younger patients. To address this pervasive limitation, a plethora of CN lesion animal model investigations have analyzed the use of systemic/local treatments for EF recovery post-RP. Most promisingly, neuregulins (NRGs) have demonstrated neurotrophic effects in both neurodegenerative disease and peripheral nerve injury models. Recently, glial growth factor 2 (GGF2) has demonstrated far superior, dose-dependent, neuroprotective/restorative effects in the CN injury rat model, as compared to previous therapeutic counterparts. Although potentially impactful, these initial findings remain limited and under-investigated. In an effort to aid clinicians, our paper reviews post-RP ED pathogenesis and currently available therapeutic tools. To stimulate further experimentation, a standardized preparation protocol and in-depth analysis of applications for the CN injury rat model is provided. Lastly, we report on NRGs, such as GGF2, and their potentially revolutionary clinical applications, in hopes of identifying relevant future research directions.
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Affiliation(s)
- Dorin Novacescu
- Doctoral School, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Alexandru Nesiu
- Department Medicine, Discipline of Urology, Vasile Goldiş Western University, Liviu Rebreanu Boulevard, Nr. 86, 310414 Arad, Romania
- Correspondence: ; Tel.: +40-753521488
| | - Razvan Bardan
- Department XV, Discipline of Urology, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Silviu Constantin Latcu
- Doctoral School, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- Department XV, Discipline of Urology, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Vlad Filodel Dema
- Doctoral School, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- Department XV, Discipline of Urology, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Alexei Croitor
- Doctoral School, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- Department XV, Discipline of Urology, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Marius Raica
- Department II, Discipline of Histology, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- Angiogenesis Research Center, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Talida Georgiana Cut
- Doctoral School, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- Department XIII, Discipline of Infectious Diseases, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- Center for Ethics in Human Genetic Identifications, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - James Walter
- Emeritus, Department of Urology, Loyola Medical Center, Maywood, IL 60153, USA
| | - Alin Adrian Cumpanas
- Department XV, Discipline of Urology, Victor Babes University of Medicine and Pharmacy Timisoara, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
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Nocera G, Jacob C. Mechanisms of Schwann cell plasticity involved in peripheral nerve repair after injury. Cell Mol Life Sci 2020; 77:3977-3989. [PMID: 32277262 PMCID: PMC7532964 DOI: 10.1007/s00018-020-03516-9] [Citation(s) in RCA: 210] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 03/09/2020] [Accepted: 03/30/2020] [Indexed: 01/01/2023]
Abstract
The great plasticity of Schwann cells (SCs), the myelinating glia of the peripheral nervous system (PNS), is a critical feature in the context of peripheral nerve regeneration following traumatic injuries and peripheral neuropathies. After a nerve damage, SCs are rapidly activated by injury-induced signals and respond by entering the repair program. During the repair program, SCs undergo dynamic cell reprogramming and morphogenic changes aimed at promoting nerve regeneration and functional recovery. SCs convert into a repair phenotype, activate negative regulators of myelination and demyelinate the damaged nerve. Moreover, they express many genes typical of their immature state as well as numerous de-novo genes. These genes modulate and drive the regeneration process by promoting neuronal survival, damaged axon disintegration, myelin clearance, axonal regrowth and guidance to their former target, and by finally remyelinating the regenerated axon. Many signaling pathways, transcriptional regulators and epigenetic mechanisms regulate these events. In this review, we discuss the main steps of the repair program with a particular focus on the molecular mechanisms that regulate SC plasticity following peripheral nerve injury.
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Affiliation(s)
- Gianluigi Nocera
- Faculty of Biology, Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany
| | - Claire Jacob
- Faculty of Biology, Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany.
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Mòdol-Caballero G, Santos D, Navarro X, Herrando-Grabulosa M. Neuregulin 1 Reduces Motoneuron Cell Death and Promotes Neurite Growth in an in Vitro Model of Motoneuron Degeneration. Front Cell Neurosci 2018; 11:431. [PMID: 29375317 PMCID: PMC5767462 DOI: 10.3389/fncel.2017.00431] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/21/2017] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disorder with no effective treatment currently available. Although the mechanisms of motoneuron (MN) death are still unclear, glutamate excitotoxicity and neuroinflammatory reaction are two main features in the neurodegenerative process of ALS. Neuregulin 1 (NRG1) is a trophic factor highly expressed in MNs and neuromuscular junctions. Several recent evidences suggest that NRG1 and their ErbB receptors are involved in ALS. However, further knowledge is still needed to clarify the role of the NRG1-ErbB pathway on MN survival. In this study we used an in vitro model of spinal cord organotypic cultures (SCOCs) subject to chronic excitotoxicity caused by DL-threo-β-hydroxyaspartic acid (THA) to characterize the effect of NRG1 on MN survival. Our results show that addition of recombinant human NRG1 (rhNRG1) to the medium significantly increased MN survival through the activation of ErbB receptors which was ablated with lapatinib (LP), an ErbB inhibitor, and reduced microglial reactivity overcoming the excitotoxicity effects. rhNRG1 activated the pro-survival PI3K/AKT pathway and restored the autophagic flux in the spinal cord culture. Moreover, addition of rhNRG1 to the medium promoted motor and sensory neurite outgrowth. These findings indicate that increasing NRG1 at the spinal cord is an interesting approach for promoting MN protection and regeneration.
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Affiliation(s)
- Guillem Mòdol-Caballero
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Daniel Santos
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Xavier Navarro
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Mireia Herrando-Grabulosa
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
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Boerboom A, Dion V, Chariot A, Franzen R. Molecular Mechanisms Involved in Schwann Cell Plasticity. Front Mol Neurosci 2017; 10:38. [PMID: 28261057 PMCID: PMC5314106 DOI: 10.3389/fnmol.2017.00038] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/31/2017] [Indexed: 01/09/2023] Open
Abstract
Schwann cell incredible plasticity is a hallmark of the utmost importance following nerve damage or in demyelinating neuropathies. After injury, Schwann cells undergo dedifferentiation before redifferentiating to promote nerve regeneration and complete functional recovery. This review updates and discusses the molecular mechanisms involved in the negative regulation of myelination as well as in the reprogramming of Schwann cells taking place early following nerve lesion to support repair. Significant advance has been made on signaling pathways and molecular components that regulate SC regenerative properties. These include for instance transcriptional regulators such as c-Jun or Notch, the MAPK and the Nrg1/ErbB2/3 pathways. This comprehensive overview ends with some therapeutical applications targeting factors that control Schwann cell plasticity and highlights the need to carefully modulate and balance this capacity to drive nerve repair.
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Affiliation(s)
| | - Valérie Dion
- GIGA-Neurosciences, University of Liège Liège, Belgium
| | - Alain Chariot
- GIGA-Molecular Biology of Diseases, University of LiègeLiège, Belgium; Walloon Excellence in Lifesciences and Biotechnology (WELBIO)Wavre, Belgium
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Lim JH, Olby NJ. Generation of pure cultures of autologous Schwann cells by use of biopsy specimens of the dorsal cutaneous branches of the cervical nerves of young adult dogs. Am J Vet Res 2017; 77:1166-74. [PMID: 27668589 DOI: 10.2460/ajvr.77.10.1166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To identify an optimal technique for isolation, purification, and amplification of Schwann cells (SCs) from biopsy specimens of the dorsal cutaneous branches of the cervical nerves of dogs. SAMPLE Biopsy specimens of dorsal cervical cutaneous nerves from the cadavers of three 1- to 2-year-old dogs. PROCEDURES Nerve specimens were dissected, predegenerated, and dissociated to isolate single cells. After culture to enhance SC growth, cells were immunopurified by use of magnetic beads. Cell purity was evaluated by assessing expression of cell surface antigens p75 (to detect SCs) and CD90 (to detect fibroblasts). Effects of various concentrations of recombinant human glial growth factor 2 (rhGGF2) on SC proliferation were tested. Cell doubling time was assessed in SC cultures with selected concentrations of rhGGF2. RESULTS Mean ± SD wet weight of nerve fascicles obtained from the biopsy specimens was 16.8 ± 2.8 mg. A mean predegeneration period of 8.6 days yielded approximately 6,000 cells/mg of nerve tissue, and primary culture yielded 43,000 cells/mg of nerve tissue in a mean of 11 days, of which 39.9 ± 9.1% expressed p75. Immunopurification with magnetic beads yielded a mean of 85.4 ± 1.9% p75-positive cells. Two passages of subculture with 10μM cytosine arabinoside further enhanced SC purity to a mean of 97.8 ± 1.2% p75-positive cells. Finally, rhGGF2 supplementation at a range of 40 to 100 ng/mL increased the SC proliferation rate up to 3-fold. CONCLUSIONS AND CLINICAL RELEVANCE SCs could be cultured from biopsy specimens of dorsal cervical cutaneous nerves and purified and expanded to generate adequate numbers for autologous transplants to treat dogs with spinal cord and peripheral nerve injuries.
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Ganguly A, McEwen C, Troy EL, Colburn RW, Caggiano AO, Schallert TJ, Parry TJ. Recovery of sensorimotor function following sciatic nerve injury across multiple rat strains. J Neurosci Methods 2017; 275:25-32. [DOI: 10.1016/j.jneumeth.2016.10.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 10/25/2016] [Accepted: 10/28/2016] [Indexed: 12/20/2022]
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Bara JJ, Turner S, Roberts S, Griffiths G, Benson R, Trivedi JM, Wright KT. High content and high throughput screening to assess the angiogenic and neurogenic actions of mesenchymal stem cells in vitro. Exp Cell Res 2015; 333:93-104. [DOI: 10.1016/j.yexcr.2014.12.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/16/2014] [Accepted: 12/30/2014] [Indexed: 01/01/2023]
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Burnett AL, Sezen SF, Hoke A, Caggiano AO, Iaci J, Lagoda G, Musicki B, Bella AJ. GGF2 is neuroprotective in a rat model of cavernous nerve injury-induced erectile dysfunction. J Sex Med 2015; 12:897-905. [PMID: 25639458 DOI: 10.1111/jsm.12834] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Erectile dysfunction is a major complication of radical prostatectomy, commonly associated with penile neuropathy. In animal models of peripheral nerve injury, glial growth factor-2 (GGF2), a member of the neuregulin family of growth factors, has neuroprotective and neurorestorative properties, but this potential has not been established after cavernous nerve (CN) injury. AIMS The effectiveness of GGF2 in preserving axonal integrity and recovering erectile function in a rat model of radical prostatectomy-associated CN injury. METHODS Adult male Sprague-Dawley rats underwent bilateral CN crush injury (BCNI) or sham surgery. Rats were administered GGF2 (0.5, 5, or 15 mg/kg) or vehicle subcutaneously 24 hour pre and 24-hour post-BCNI, and once weekly for 5 weeks. Erectile function was assessed in response to electrical stimulation of the CN. CN survival was assessed by fluorogold retrograde axonal tracing in major pelvic ganglia (MPG). Unmyelinated axons in the CNs were quantitated by electron microscopy. MAIN OUTCOME MEASURES Erectile function recovery, CN survival, and unmyelinated CN axon preservation in response to GGF2 treatment following BCNI. RESULTS Erectile function was decreased (P < 0.05) after BCNI, and it was improved (P < 0.05) by all doses of GGF2. The number of fluorogold-labeled cells in the MPG was reduced (P < 0.05) by BCNI and was increased (P < 0.05) by GGF2 (0.5 and 5 mg/kg). The percentage of denervated Schwann cells in the BCNI group was higher (P < 0.05) than that in the sham-treated group and was decreased (P < 0.05) in the GGF2-treated (5 mg/kg) BCNI group. In the BCNI + GGF2 (5 mg/kg) group, the unmyelinated fiber histogram demonstrated a rightward shift, indicating an increased number of unmyelinated axons per Schwann cell compared with the BCNI group. CONCLUSIONS GGF2 promotes erectile function recovery following CN injury in conjunction with preserving unmyelinated CN fibers. Our findings suggest the clinical opportunity to develop GGF2 as a neuroprotective therapy for radical prostatectomy.
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Affiliation(s)
- Arthur L Burnett
- Department of Urology, The James Buchanan Brady Urological Institute, The Johns Hopkins School of Medicine, Baltimore, MD, USA
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Gambarotta G, Ronchi G, Geuna S, Perroteau I. Neuregulin 1 isoforms could be an effective therapeutic candidate to promote peripheral nerve regeneration. Neural Regen Res 2014; 9:1183-5. [PMID: 25206780 PMCID: PMC4146285 DOI: 10.4103/1673-5374.135324] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2014] [Indexed: 12/29/2022] Open
Affiliation(s)
- Giovanna Gambarotta
- Department of Clinical and Biological Sciences, University of Turin, Italy ; Neuroscience Institute of Turin (NIT), University of Turin, Italy
| | - Giulia Ronchi
- Department of Clinical and Biological Sciences, University of Turin, Italy ; Neuroscience Institute of the "Cavalieri Ottolenghi" Foundation (NICO), University of Turin, Italy
| | - Stefano Geuna
- Department of Clinical and Biological Sciences, University of Turin, Italy ; Neuroscience Institute of Turin (NIT), University of Turin, Italy ; Neuroscience Institute of the "Cavalieri Ottolenghi" Foundation (NICO), University of Turin, Italy
| | - Isabelle Perroteau
- Department of Clinical and Biological Sciences, University of Turin, Italy ; Neuroscience Institute of Turin (NIT), University of Turin, Italy
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Lee HJ, Shin YK, Park HT. Mitogen Activated Protein Kinase Family Proteins and c-jun Signaling in Injury-induced Schwann Cell Plasticity. Exp Neurobiol 2014; 23:130-7. [PMID: 24963277 PMCID: PMC4065826 DOI: 10.5607/en.2014.23.2.130] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 05/21/2014] [Accepted: 05/21/2014] [Indexed: 12/31/2022] Open
Abstract
Schwann cells (SCs) in the peripheral nerves myelinate axons during postnatal development to allow saltatory conduction of nerve impulses. Well-organized structures of myelin sheathes are maintained throughout life unless nerves are insulted. After peripheral nerve injury, unidentified signals from injured nerves drive SC dedifferentiation into an immature state. Dedifferentiated SCs participate in axonal regeneration by producing neurotrophic factors and removing degenerating nerve debris. In this review, we focus on the role of mitogen activated protein kinase family proteins (MAP kinases) in SC dedifferentiation. In addition, we will highlight neuregulin 1 and the transcription factor c-jun as upstream and downstream signals for MAP kinases in SC responses to nerve injury.
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Affiliation(s)
- Hye Jeong Lee
- Department of Pharmacology, Mitochondria Hub Regulation Center (MHRC), College of Medicine, Dong-A University, Busan 602-714, Korea
| | - Yoon Kyung Shin
- Department of Physiology, Mitochondria Hub Regulation Center (MHRC), College of Medicine, Dong-A University, Busan 602-714, Korea
| | - Hwan Tae Park
- Department of Physiology, Mitochondria Hub Regulation Center (MHRC), College of Medicine, Dong-A University, Busan 602-714, Korea
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Fricker FR, Antunes-Martins A, Galino J, Paramsothy R, La Russa F, Perkins J, Goldberg R, Brelstaff J, Zhu N, McMahon SB, Orengo C, Garratt AN, Birchmeier C, Bennett DLH. Axonal neuregulin 1 is a rate limiting but not essential factor for nerve remyelination. ACTA ACUST UNITED AC 2013; 136:2279-97. [PMID: 23801741 PMCID: PMC3692042 DOI: 10.1093/brain/awt148] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Neuregulin 1 acts as an axonal signal that regulates multiple aspects of Schwann cell
development including the survival and migration of Schwann cell precursors, the
ensheathment of axons and subsequent elaboration of the myelin sheath. To examine the role
of this factor in remyelination and repair following nerve injury, we ablated neuregulin 1
in the adult nervous system using a tamoxifen inducible Cre recombinase transgenic mouse
system. The loss of neuregulin 1 impaired remyelination after nerve crush, but did not
affect Schwann cell proliferation associated with Wallerian degeneration or axon
regeneration or the clearance of myelin debris by macrophages. Myelination changes were
most marked at 10 days after injury but still apparent at 2 months post-crush.
Transcriptional analysis demonstrated reduced expression of myelin-related genes during
nerve repair in animals lacking neuregulin 1. We also studied repair over a prolonged time
course in a more severe injury model, sciatic nerve transection and reanastamosis. In the
neuregulin 1 mutant mice, remyelination was again impaired 2 months after nerve
transection and reanastamosis. However, by 3 months post-injury axons lacking neuregulin 1
were effectively remyelinated and virtually indistinguishable from control. Neuregulin 1
signalling is therefore an important factor in nerve repair regulating the rate of
remyelination and functional recovery at early phases following injury. In contrast to
development, however, the determination of myelination fate following nerve injury is not
dependent on axonal neuregulin 1 expression. In the early phase following injury, axonal
neuregulin 1 therefore promotes nerve repair, but at late stages other signalling pathways
appear to compensate.
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Affiliation(s)
- Florence R Fricker
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU UK
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Abstract
Neuregulin 1 (NRG1) is an axon-derived factor that is critical for Schwann cell (SC) development and myelinogenesis in a manner dependent on transmembrane tyrosine kinases ErbB2 and ErbB3. Recent studies suggest that NRG1 signaling plays a role in remyelination of regenerated nerves after injury. In this study, we investigated the role of Erbin, a protein that interacts with ErbB2 in remyelination of injured nerves. We show that Erbin expression increased dramatically in injured nerves. Myelinated axons were fewer, and g-ratios of those that were myelinated were increased in erbin(-/-) mice, which were impaired in functional recovery from nerve injury. These results indicate a necessary role of Erbin in remyelination of regenerating axons. Erbin ablation had little effect on numbers of BrdU-labeled and TUNEL-labeled SCs, suggesting mechanisms independent of altered proliferation or apoptosis. We demonstrated that Erbin mutant mice were impaired in raising or maintaining the levels of ErbB2 and in producing NRG1 in axons. Together, these observations demonstrate that Erbin is required for remyelination of regenerated axons after injury, probably by regulating ErbB2 and NRG1 levels, identifying a novel player in regulating remyelination.
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Chang HM, Shyu MK, Tseng GF, Liu CH, Chang HS, Lan CT, Hsu WM, Liao WC. Neuregulin facilitates nerve regeneration by speeding Schwann cell migration via ErbB2/3-dependent FAK pathway. PLoS One 2013; 8:e53444. [PMID: 23301073 PMCID: PMC3534691 DOI: 10.1371/journal.pone.0053444] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 11/28/2012] [Indexed: 11/19/2022] Open
Abstract
Background Adequate migration of Schwann cells (Sc) is crucial for axon-guidance in the regenerative process after peripheral nerve injury (PNI). Considering neuregulin-erbB-FAK signaling is an essential pathway participating in the regulation of Sc migration during development, the present study is aimed to examine whether neuregulin would exert its beneficial effects on adult following PNI and further determine the potential changes of downstream pathway engaged in neuro-regeneration by both in vitro and in vivo approaches. Methodology and Principal Findings Cultured RSC96 cells treated with neuregulin were processed for erbB2/3 immunofluorescence and FAK immunoblotings. The potential effects of neuregulin on Sc were assessed by cell adherence, spreading, and migration assays. In order to evaluate the functional significance of neuregulin on neuro-regeneration, the in vivo model of PNI was performed by chronic end-to-side neurorrhaphy (ESN). In vitro studies indicated that after neuregulin incubation, erbB2/3 were not only expressed in cell membranes, but also distributed throughout the cytoplasm and nucleus of RSC96 cells. Activation of erbB2/3 was positively correlated with FAK phosphorylation. Neuregulin also increases Sc adherence, spreading, and migration by 127.2±5.0%, 336.8±3.0%, and 80.0±5.7%, respectively. As for in vivo study, neuregulin significantly accelerates the speed of Sc migration and increases Sc expression in the distal stump of injured nerves. Retrograde labeling and compound muscle action potential recordings (CMAP) also showed that neuregulin successfully facilitates nerve regeneration by eliciting noticeably larger CMAP and promoting quick re-innervation of target muscles. Conclusions As neuregulin successfully improves axo-glial interaction by speeding Sc migration via the erbB2/3-FAK pathway, therapeutic use of neuregulin may thus serve as a promising strategy to facilitate the progress of nerve regeneration after PNI.
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Affiliation(s)
- Hung-Ming Chang
- Department of Anatomy, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ming-Kwang Shyu
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan
| | - Guo-Fang Tseng
- Department of Anatomy, College of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Chiung-Hui Liu
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hung-Shuo Chang
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chyn-Tair Lan
- Department of Anatomy, Faculty of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Wen-Ming Hsu
- Division of Pediatric Surgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Wen-Chieh Liao
- Department of Anatomy, Faculty of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan
- * E-mail:
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Gambarotta G, Fregnan F, Gnavi S, Perroteau I. Neuregulin 1 role in Schwann cell regulation and potential applications to promote peripheral nerve regeneration. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 108:223-56. [PMID: 24083437 DOI: 10.1016/b978-0-12-410499-0.00009-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neuregulin 1 (NRG1) is a multifunctional and versatile protein: its numerous isoforms can signal in a paracrine, autocrine, or juxtacrine manner, playing a fundamental role during the development of the peripheral nervous system and during the process of nerve repair, suggesting that the treatment with NRG1 could improve functional outcome following injury. Accordingly, the use of NRG1 in vivo has already yielded encouraging results. The aim of this review is to focus on the role played by the different NRG1 isoforms during peripheral nerve regeneration and remyelination and to identify good candidates to be used for the development of tissue engineered medical devices delivering NRG1, with the objective of promoting better nerve repair.
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Affiliation(s)
- Giovanna Gambarotta
- Nerve Regeneration Group, Department of Clinical and Biological Sciences, University of Torino, Torino, Italy.
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Neural and molecular features on Charcot-Marie-Tooth disease plasticity and therapy. Neural Plast 2012; 2012:171636. [PMID: 22745917 PMCID: PMC3382403 DOI: 10.1155/2012/171636] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 04/16/2012] [Indexed: 12/21/2022] Open
Abstract
In the peripheral nervous system disorders plasticity is related to changes on the axon and Schwann cell biology, and the synaptic formations and connections, which could be also a focus for therapeutic research. Charcot-Marie-Tooth disease (CMT) represents a large group of inherited peripheral neuropathies that involve mainly both motor and sensory nerves and induce muscular atrophy and weakness. Genetic analysis has identified several pathways and molecular mechanisms involving myelin structure and proper nerve myelination, transcriptional regulation, protein turnover, vesicle trafficking, axonal transport and mitochondrial dynamics. These pathogenic mechanisms affect the continuous signaling and dialogue between the Schwann cell and the axon, having as final result the loss of myelin and nerve maintenance; however, some late onset axonal CMT neuropathies are a consequence of Schwann cell specific changes not affecting myelin. Comprehension of molecular pathways involved in Schwann cell-axonal interactions is likely not only to increase the understanding of nerve biology but also to identify the molecular targets and cell pathways to design novel therapeutic approaches for inherited neuropathies but also for most common peripheral neuropathies. These approaches should improve the plasticity of the synaptic connections at the neuromuscular junction and regenerate cell viability based on improving myelin and axon interaction.
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Xu C, Lv L, Zheng G, Li B, Gao L, Sun Y. Neuregulin1β1 protects oligodendrocyte progenitor cells from oxygen glucose deprivation injury induced apoptosis via ErbB4-dependent activation of PI3-kinase/Akt. Brain Res 2012; 1467:104-12. [PMID: 22659027 DOI: 10.1016/j.brainres.2012.05.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 05/03/2012] [Accepted: 05/22/2012] [Indexed: 02/07/2023]
Abstract
Mounting evidence suggests that the injury of oligodendrocyte progenitor cells (OPCs) caused by hypoxia plays a pivotal role in periventricular white matter injury (PWMI) causation. We investigated the potential role of active extracellular domain of Neuregulin1 isotypeβ1 (NRG1β1)/ErbB signaling in protecting OPCs from oxygen glucose deprivation (OGD) induced apoptosis. At different time points, endogenous NRG1β1 protein was analyzed after OGD. Escalating dosages of NRG1β1 were used to treat OPCs with OGD, and the apoptosis was measured, as well as the expression of ErbB receptors, Akt and Erk phosphorylation and caspase3 activation. OGD damage resulted in decreased expression of endogenous NRG1β1. In parallel, NRG1β1 treatment promoted the expression of p-ErbB4 receptor, phosphorylated Akt and inhibited caspase3 activation. Furthermore, the activation of PI3-kinase/Akt by NRG1β1 was ErbB4 dependent. Our data demonstrated that NRG1β1 protected OPCs from OGD induced apoptosis and the possible protective mechanism is linking with ErbB4-dependent activation of PI3-kinase/Akt pathway.
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Affiliation(s)
- Chongchong Xu
- Department of Anatomy, Histology and Embryology, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, PR China
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17
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Fricker FR, Bennett DL. The role of neuregulin-1 in the response to nerve injury. FUTURE NEUROLOGY 2011; 6:809-822. [PMID: 22121335 DOI: 10.2217/fnl.11.45] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Axons and Schwann cells exist in a highly interdependent relationship: damage to one cell type invariably leads to pathophysiological changes in the other. Greater understanding of communication between these cell types will not only give insight into peripheral nerve development, but also the reaction to and recovery from peripheral nerve injury. The type III isoform of neuregulin-1 (NRG1) has emerged as a key signaling factor that is expressed on axons and, through binding to erbB2/3 receptors on Schwann cells, regulates multiple phases of their development. In adulthood, NRG1 is dispensable for the maintenance of the myelin sheath; however, this factor is required for both axon regeneration and remyelination following nerve injury. The outcome of NRG1 signaling depends on interactions with other pathways within Schwann cells such as Notch, integrin and cAMP signaling. In certain circumstances, this signaling pathway may be maladaptive; for instance, direct binding of Mycobacterium leprae onto erbB2 receptors produces excessive activation and can actually promote demyelination. Attempts to modulate this pathway in order to promote nerve repair will therefore need to give consideration to the exact isoform used, as well as how it is processed and the context in which it is presented to the Schwann cell.
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18
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Whittaker MT, Zai LJ, Lee HJ, Pajoohesh-Ganji A, Wu J, Sharp A, Wyse R, Wrathall JR. GGF2 (Nrg1-β3) treatment enhances NG2+ cell response and improves functional recovery after spinal cord injury. Glia 2011; 60:281-94. [PMID: 22042562 DOI: 10.1002/glia.21262] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 10/06/2011] [Indexed: 12/13/2022]
Abstract
The adult spinal cord contains a pool of endogenous glial precursor cells, which spontaneously respond to spinal cord injury (SCI) with increased proliferation. These include oligodendrocyte precursor cells that express the NG2 proteoglycan and can differentiate into mature oligodendrocytes. Thus, a potential approach for SCI treatment is to enhance the proliferation and differentiation of these cells to yield more functional mature glia and improve remyelination of surviving axons. We previously reported that soluble glial growth factor 2 (GGF2)- and basic fibroblast growth factor 2 (FGF2)-stimulated growth of NG2(+) cells purified from injured spinal cord in primary culture. This study examines the effects of systemic administration of GGF2 and/or FGF2 after standardized contusive SCI in vivo in both rat and mouse models. In Sprague-Dawley rats, 1 week of GGF2 administration, beginning 24 h after injury, enhanced NG2(+) cell proliferation, oligodendrogenesis, chronic white matter at the injury epicenter, and recovery of hind limb function. In 2',3'-cyclic-nucleotide 3'-phosphodiesterase-enhanced green fluorescent protein mice, GGF2 treatment resulted in increased oligodendrogenesis and improved functional recovery, as well as elevated expression of the stem cell transcription factor Sox2 by oligodendrocyte lineage cells. Although oligodendrocyte number was increased chronically after SCI in GGF2-treated mice, no evidence of increased white matter was detected. However, GGF2 treatment significantly increased levels of P0 protein-containing peripheral myelin, produced by Schwann cells that infiltrate the injured spinal cord. Our results suggest that GGF2 may have therapeutic potential for SCI by enhancing endogenous recovery processes in a clinically relevant time frame.
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Affiliation(s)
- Matthew T Whittaker
- Department of Neuroscience, Georgetown University, Washington, District of Columbia 20057, USA
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19
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Joung I, Yoo M, Woo JH, Chang CY, Heo H, Kwon YK. Secretion of EGF-like domain of heregulinβ promotes axonal growth and functional recovery of injured sciatic nerve. Mol Cells 2010; 30:477-84. [PMID: 20957456 DOI: 10.1007/s10059-010-0137-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 08/16/2010] [Indexed: 01/12/2023] Open
Abstract
Neuregulin 1 (NRG1) and epidermal growth factor receptor (ErbB) signaling pathways control Schwann cells during axonal regeneration in an injured peripheral nervous system. We investigated whether a persistent supply of recombinant NRG1 to the injury site could improve axonal growth and recovery of sensory and motor functions in rats during nerve regeneration. We generated a recombinant adenovirus expressing a secreted form of EGF-like domain from Heregulinβ (sHRGβE-Ad). This virus, sHRGβE-Ad allowed for the secretion of 30-50 ng of small sHRGβE peptides per 10(7-8) virus particle outside cells and was able to phosphorylate ErbB receptors. Transduction of the concentrated sHRGβE-Ad into an axotomy model of sciatic nerve damage caused an effective promotion of nerve regeneration, as shown by histological features of the axons and Schwann cells, as well as increased expression of neurofilaments, GAP43 and S100 in the distal stump of the injury site. This result is consistent with longer axon lengths and thicker calibers observed in the sHRGβE-Ad treated animals. Furthermore, sensory and motor functions were significantly improved in sHRGβE-Ad treated animals when evaluated by a behavioral test. These results suggest a therapeutic potential for sHRGβE-Ad in treatment of peripheral nerve injury.
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Affiliation(s)
- Insil Joung
- Department of Biological Sciences, Hanseo University, Seosan, 352-820, Korea
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20
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Coert JH. Pathophysiology of nerve regeneration and nerve reconstruction in burned patients. Burns 2010; 36:593-8. [PMID: 20071095 DOI: 10.1016/j.burns.2009.10.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 08/09/2009] [Accepted: 10/06/2009] [Indexed: 12/18/2022]
Abstract
In extensive burns peripheral nerves can be involved. The injury to the nerve can be direct by thermal or electrical burns, but nerves can also be indirectly affected by the systemic reaction that follows the burn. Mediators will be released causing a neuropathy to nerves remote from the involved area. Involved mediators and possible therapeutic options will be discussed. In burned patients nerves can be reconstructed using autologous nerve grafts or nerve conduits. A key factor is an adequate wound debridement and a well-vascularized bed to optimize the outgrowth of the axons. Early free tissue transfers have shown promising results.
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Affiliation(s)
- J Henk Coert
- Department of Plastic Surgery and Hand Surgery, Erasmus University Medical Center and Sint Franciscus Hospital, Office HS-511, Rotterdam, The Netherlands.
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21
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Bian Y, Sun M, Silver M, Ho KKL, Marchionni MA, Caggiano AO, Stone JR, Amende I, Hampton TG, Morgan JP, Yan X. Neuregulin-1 attenuated doxorubicin-induced decrease in cardiac troponins. Am J Physiol Heart Circ Physiol 2009; 297:H1974-83. [PMID: 19801490 DOI: 10.1152/ajpheart.01010.2008] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neuregulin-1 (NRG1) is a potential therapeutic agent for the treatment of doxorubicin (Dox)-induced heart failure. NRG1, however, activates the erbB2 receptor, which is frequently overexpressed in breast cancers. It is, therefore, important to understand how NRG1, via erbB2, protects the heart against Dox cardiotoxicity. Here, we studied NRG1-erbB2 signaling in Dox-treated mice hearts and in isolated neonatal rat ventricular myocytes (NRVM). Male C57BL/6 mice were treated with recombinant NRG1 before and daily after a single dose of Dox. Cardiac function was determined by catheterization. Two-week survival was analyzed by the Kaplan-Meier method. Cardiac troponins [cardiac troponin I (cTnI) and cardiac troponin T (cTnT)] and phosphorylated Akt protein levels were determined in mice hearts and in NRVM by Western blot analysis. Activation of caspases and ubiquitinylation of troponins were determined in NRVM by caspase assay and immunoprecipitation. NRG1 significantly improved survival and cardiac function in Dox-treated mice. NRG1 reduced the decrease in cTnI, cTnT, and cardiac troponin C (cTnC) and maintained Akt phosphorylation in Dox-treated mice hearts. NRG1 reduced the decrease in cTnI and cTnT mRNA and proteins in Dox-treated NRVM. Inhibition of erbB2, phosphoinositide 3-kinase (PI3K), Akt, and mTOR blocked the protective effects of NRG1 on cTnI and cTnT in NRVM. NRG1 significantly reduced Dox-induced caspase activation, which degraded troponins, in NRVM. NRG1 reduced Dox-induced proteasome degradation of cTnI. NRG1 attenuates Dox-induced decrease in cardiac troponins by increasing transcription and translation and by inhibiting caspase activation and proteasome degradation of troponin proteins. NRG1 maintains cardiac troponins by the erbB2-PI3K pathway, which may lessen Dox-induced cardiac dysfunction.
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Affiliation(s)
- Yun Bian
- Cardiovascular Research, Caritas St. Elizabeth's Medical Center, 736 Cambridge St. CBR3, Boston, MA 02135, USA
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22
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Abstract
Whereas the central nervous system (CNS) usually cannot regenerate, peripheral nerves regenerate spontaneously after injury because of a permissive environment and activation of the intrinsic growth capacity of neurons. Functional regeneration requires axon regrowth and remyelination of the regenerated axons by Schwann cells. Multiple factors including neurotrophic factors, extracellular matrix (ECM) proteins, and hormones participate in Schwann cell dedifferentiation, proliferation, and remyelination. We describe the current understanding of peripheral axon regeneration and focus on the molecules and potential mechanisms involved in remyelination.
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Affiliation(s)
- Zu-Lin Chen
- Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY 10021, USA.
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23
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Abstract
The incidence of DM is rapidly growing among Americans. DM will rival cancer and heart disease in terms of cost and suffering. The National Institute of Health is tripling the research dollars that are spent on diabetic-related research in an attempt to combat this disease. Urologists are on the front line in the diagnosis and treatment of the complications of DM. The complications of DM that we reviewed in this article, diabetic cystopathy and diabetic ED, can occur in the early stage of DM and often progress in a silent fashion. More awareness and interest are needed to improve our understanding of diabetic complications in urology. Exciting new approaches in the treatment of diabetic cystopathy and ED are being investigated.
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Affiliation(s)
- Katsumi Sasaki
- Department of Urology, Division of Female Urology, University of Pittsburgh School of Medicine, Suite 700 Kaufmann Building, 3471 Fifth Avenue, Pittsburgh, PA 15213, USA
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24
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McDonald DS, Zochodne DW. An injectable nerve regeneration chamber for studies of unstable soluble growth factors. J Neurosci Methods 2003; 122:171-8. [PMID: 12573476 DOI: 10.1016/s0165-0270(02)00319-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Modern surgical techniques cannot guarantee functional recovery following peripheral nerve injuries. Research into factors that may influence nerve regeneration has therefore assumed a prominent potential therapeutic role. We report here on the development of an approach to allow for direct manipulation of the microenvironment of regenerating peripheral nerve axons. We show that solutions can be delivered directly to this local milieu in vivo and that such a delivery can be performed multiple times over an extended period, potentially facilitating studies of multiple molecular players that act locally. We also demonstrate that the bundle of regenerated axons are amenable to morphological analysis by 21 days and that the injection system remains patent for at least 21 days.
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Affiliation(s)
- D S McDonald
- Department of Clinical Neurosciences, University of Calgary, Room 182A, 3330 Hospital Drive, Alta, Calgary, Canada T2N 4N1
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25
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Haggiag S, Zhang PL, Slutzky G, Shinder V, Kumar A, Chebath J, Revel M. Stimulation of myelin gene expression in vitro and of sciatic nerve remyelination by interleukin-6 receptor-interleukin-6 chimera. J Neurosci Res 2001; 64:564-74. [PMID: 11398179 DOI: 10.1002/jnr.1108] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Induction of myelin gene expression denotes the last stage of differentiation of myelinating glial cells. Following peripheral nerve transection, Schwann cells (SC) lose myelin gene expression and proliferate, resembling premyelinating embryonic SC (eSC). We show that a fusion protein of the soluble interleukin-6 receptor to interleukin-6 (IL6RIL6), a potent activator of the gp130 signaling receptor, is an inducer of MBP and Po gene products in rat E18 embryonic dorsal root ganglia (DRG) 3 day cultures. Cells whose growth is dependent on the IL6RIL6 chimera were isolated from DRG. These cells (designated CH cells) express Krox-20, as do promyelinating and myelinating SC (mSC). IL6RIL6 induces Po and MBP in CH cells and their cocultures with neurons. In addition, IL6RIL6 leads to a disappearance of Pax-3, a marker of eSC and nonmyelinating Schwann cells (nmSC). Glial fibrillary acidic protein, present in nmSC, is not significantly induced by IL6RIL6. The CH cells acquire glial morphology when exposed to IL6RIL6 and cover axons in cocultures. In a sciatic nerve-derived SC line, IL6RIL6 also induces Po and triggers a rapid attachment along axons. In vivo administration of IL6RIL6 intraperitoneally to rats after sciatic nerve transection and resuture increases 4-fold the number of myelinated nerve fibers (MF) measured on day 12, 2.5-5 mm distal to the suture. The stimulation by IL6RIL6 treatment is highest (7.1-fold) at the more distant 5 mm site, and the thickness of myelin sheaths is increased. Compared to known SC growth factors, the gp130 activator IL6RIL6 appears to combine both in vitro mitogenic effects and promotion of myelin gene expression.
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Affiliation(s)
- S Haggiag
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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26
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Abstract
Neurologic erectile dysfunction presents a diagnostic and treatment challenge to the internist and urologist. Multiple chronic disease modalities and traumatic etiologies exist. Education regarding these conditions and a detailed and thorough history and office work-up are the best resources for the clinician. Treatment can follow the model of proceeding from the least to most invasive procedure (process of care), taking into account patient and partner satisfaction. Because the psychology of grief and loss may enter into treatment of some neurologic conditions (e.g., erectile dysfunction after radical retropubic prostatectomy, spinal cord injury, or chronic diseases), a whole-patient approach encompassing psychotherapy is warranted.
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Affiliation(s)
- A Nehra
- Department of Urology, Mayo Medical School, and Mayo Clinic and Foundation, Rochester, Minnesota, USA.
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27
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Garratt AN, Voiculescu O, Topilko P, Charnay P, Birchmeier C. A dual role of erbB2 in myelination and in expansion of the schwann cell precursor pool. J Cell Biol 2000; 148:1035-46. [PMID: 10704452 PMCID: PMC2174554 DOI: 10.1083/jcb.148.5.1035] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuregulin-1 provides an important axonally derived signal for the survival and growth of developing Schwann cells, which is transmitted by the ErbB2/ErbB3 receptor tyrosine kinases. Null mutations of the neuregulin-1, erbB2, or erbB3 mouse genes cause severe deficits in early Schwann cell development. Here, we employ Cre-loxP technology to introduce erbB2 mutations late in Schwann cell development, using a Krox20-cre allele. Cre-mediated erbB2 ablation occurs perinatally in peripheral nerves, but already at E11 within spinal roots. The mutant mice exhibit a widespread peripheral neuropathy characterized by abnormally thin myelin sheaths, containing fewer myelin wraps. In addition, in spinal roots the Schwann cell precursor pool is not correctly established. Thus, the Neuregulin signaling system functions during multiple stages of Schwann cell development and is essential for correct myelination. The thickness of the myelin sheath is determined by the axon diameter, and we suggest that trophic signals provided by the nerve determine the number of times a Schwann cell wraps an axon.
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Affiliation(s)
| | | | - Piotr Topilko
- INSERM U368, École Normale Supérieure, 75230 Paris 05, France
| | - Patrick Charnay
- INSERM U368, École Normale Supérieure, 75230 Paris 05, France
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28
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Affiliation(s)
- K Adlkofer
- Molecular Neurobiology Lab, Salk Institute, La Jolla, California
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29
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Haggiag S, Chebath J, Revel M. Induction of myelin gene expression in Schwann cell cultures by an interleukin-6 receptor-interleukin-6 chimera. FEBS Lett 1999; 457:200-4. [PMID: 10471778 DOI: 10.1016/s0014-5793(99)01040-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Expression of myelin basic protein (MBP) and Po gene products is induced during the final postnatal maturation of Schwann cells and reinduced during nerve regeneration. We show that a chimeric protein containing interleukin-6 fused to its soluble receptor (IL6RIL6 chimera) induces MBP and Po RNAs and proteins in cultures of dorsal root ganglia (DRG) from 14 day old mouse embryos. Activation of gp130 signaling by IL6RIL6 appears comparable to cyclic AMP elevating agents to induce the myelin gene products in DRG and in pure Schwann cell cultures.
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Affiliation(s)
- S Haggiag
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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30
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Liu K, Chen LE, Seaber AV, Goldner RV, Urbaniak JR. Motor functional and morphological findings following end-to-side neurorrhaphy in the rat model. J Orthop Res 1999; 17:293-300. [PMID: 10221848 DOI: 10.1002/jor.1100170220] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Nerve repair cannot always be achieved by the conventional end-to-end technique. This study evaluated the functional recovery of nerves repaired with end-to-side neurorrhaphy in a rat model. The right peroneal nerves of 80 female rats were transected and divided into four groups. In group A, the nerve ends were separated and remained unrepaired; in group B, the distal peroneal ends were directly sutured to the epineurium of the tibial nerves in end-to-side fashion; in group C, the distal ends were sutured through an epineurial window at the repair site in end-to-side fashion; and in group D, the nerve ends were reconnected by the traditional end-to-end technique. Evaluation included gait analysis by calculation of a peroneal functional index, measurement of contractile function of the extensor digitorum longus muscle, wet weight of the extensor digitorum longus, and histological examination. The findings of this study suggested the following: (a) end-to-side neurorrhaphy allows effective motor functional recovery, demonstrated by earlier improvement of the peroneal functional index, stronger muscle contractile function, greater muscle weight, and higher density of regenerated axons compared with unrepaired nerves; (b) removal of the epineurium of the donor nerve at the nerve coaptation site increases the effectiveness of end-to-side neurorrhaphy, but the epineurium appears to be a partial barrier to axonal regeneration; (c) removal of the epineurium does not affect the structure and function of the donor nerve; and (d) end-to-end repair achieved the best functional recovery among the four groups; therefore, end-to-side repair should be considered as a potential alternative only when no proximal nerve is available.
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Affiliation(s)
- K Liu
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
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