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Babaliari E, Ranella A, Stratakis E. Microfluidic Systems for Neural Cell Studies. Bioengineering (Basel) 2023; 10:902. [PMID: 37627787 PMCID: PMC10451731 DOI: 10.3390/bioengineering10080902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/05/2023] [Accepted: 07/25/2023] [Indexed: 08/27/2023] Open
Abstract
Whereas the axons of the peripheral nervous system (PNS) spontaneously regenerate after an injury, the occurring regeneration is rarely successful because axons are usually directed by inappropriate cues. Therefore, finding successful ways to guide neurite outgrowth, in vitro, is essential for neurogenesis. Microfluidic systems reflect more appropriately the in vivo environment of cells in tissues such as the normal fluid flow within the body, consistent nutrient delivery, effective waste removal, and mechanical stimulation due to fluid shear forces. At the same time, it has been well reported that topography affects neuronal outgrowth, orientation, and differentiation. In this review, we demonstrate how topography and microfluidic flow affect neuronal behavior, either separately or in synergy, and highlight the efficacy of microfluidic systems in promoting neuronal outgrowth.
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Affiliation(s)
- Eleftheria Babaliari
- Foundation for Research and Technology—Hellas (F.O.R.T.H.), Institute of Electronic Structure and Laser (I.E.S.L.), Vasilika Vouton, 70013 Heraklion, Greece;
| | - Anthi Ranella
- Foundation for Research and Technology—Hellas (F.O.R.T.H.), Institute of Electronic Structure and Laser (I.E.S.L.), Vasilika Vouton, 70013 Heraklion, Greece;
| | - Emmanuel Stratakis
- Foundation for Research and Technology—Hellas (F.O.R.T.H.), Institute of Electronic Structure and Laser (I.E.S.L.), Vasilika Vouton, 70013 Heraklion, Greece;
- Department of Physics, University of Crete, 70013 Heraklion, Greece
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2
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Malik T, Malik A, Abd-Elsayed A. Pathophysiology of Work-Related Neuropathies. Biomedicines 2023; 11:1745. [PMID: 37371842 DOI: 10.3390/biomedicines11061745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Work-related injuries are common. The cost of these injuries is around USD 176 billion to USD 350 billion a year. A significant number of work-related injuries involve nerve damage or dysfunction. Injuries may heal with full recovery of function, but those involving nerve damage may result in significant loss of function or very prolonged recovery. While many factors can predispose a person to suffer nerve damage, in most cases, it is a multifactorial issue that involves both intrinsic and extrinsic factors. This makes preventing work-related injuries hard. To date, no evidence-based guidelines are available to clinicians to evaluate work-related nerve dysfunction. While the symptoms range from poor endurance to cramping to clear loss of motor and sensory functions, not all nerves are equally vulnerable. The common risk factors for nerve damage are a superficial location, a long course, an acute change in trajectory along the course, and coursing through tight spaces. The pathophysiology of acute nerve injury is well known, but that of chronic nerve injury is much less well understood. The two most common mechanisms of nerve injury are stretching and compression. Chronic mild to moderate compression is the most common mechanism of nerve injury and it elicits a characteristic response from Schwann cells, which is different from the one when nerve is acutely injured. It is important to gain a better understanding of work-related nerve dysfunction, both from health and from regulatory standpoints. Currently, management depends upon etiology of nerve damage, recovery is often poor if nerves are badly damaged or treatment is not instituted early. This article reviews the current pathophysiology of chronic nerve injury. Chronic nerve injury animal models have contributed a lot to our understanding but it is still not complete. Better understanding of chronic nerve injury pathology will result in identification of novel and more effective targets for pharmacological interventions.
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Affiliation(s)
- Tariq Malik
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, B6/319 CSC, Madison, WI 53792-3272, USA
| | - Ahmed Malik
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, B6/319 CSC, Madison, WI 53792-3272, USA
| | - Alaa Abd-Elsayed
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, B6/319 CSC, Madison, WI 53792-3272, USA
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3
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Intisar A, Woo H, Kang HG, Kim WH, Shin HY, Kim MY, Kim YS, Mo YJ, Lee YI, Kim MS. Electroceutical approach ameliorates intracellular PMP22 aggregation and promotes pro-myelinating pathways in a CMT1A in vitro model. Biosens Bioelectron 2023; 224:115055. [PMID: 36630746 DOI: 10.1016/j.bios.2022.115055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/01/2023]
Abstract
Charcot-Marie-Tooth disease subtype 1A (CMT1A) is one of the most prevalent demyelinating peripheral neuropathies worldwide, caused by duplication of the peripheral myelin protein 22 (PMP22) gene, which is expressed primarily in Schwann cells (SCs). PMP22 overexpression in SCs leads to intracellular aggregation of the protein, which eventually results in demyelination. Unfortunately, previous biochemical approaches have not resulted in an approved treatment for CMT1A disease, compelling the pursuit for a biophysical approach such as electrical stimulation (ES). However, the effects of ES on CMT1A SCs have remained unexplored. In this study, we established PMP22-overexpressed Schwannoma cells as a CMT1A in vitro model, and investigated the biomolecular changes upon applying ES via a custom-made high-throughput ES platform, screening for the condition that delivers optimal therapeutic effects. While PMP22-overexpressed Schwannoma exhibited intracellular PMP22 aggregation, ES at 20 Hz for 1 h improved this phenomenon, bringing PMP22 distribution closer to healthy condition. ES at this condition also enhanced the expression of the genes encoding myelin basic protein (MBP) and myelin-associated glycoprotein (MAG), which are essential for assembling myelin sheath. Furthermore, ES altered the gene expression for myelination-regulating transcription factors Krox-20, Oct-6, c-Jun and Sox10, inducing pro-myelinating effects in PMP22-overexpressed Schwannoma. While electroceuticals has previously been applied in the peripheral nervous system towards acquired peripheral neuropathies such as pain and nerve injury, this study demonstrates its effectiveness towards ameliorating biomolecular abnormalities in an in vitro model of CMT1A, an inherited peripheral neuropathy. These findings will facilitate the clinical translation of an electroceutical treatment for CMT1A.
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Affiliation(s)
- Aseer Intisar
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Hanwoong Woo
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Hyun Gyu Kang
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Woon-Hae Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea; CTCELLS Corp., Daegu, 42988, Republic of Korea
| | - Hyun Young Shin
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea; CTCELLS Corp., Daegu, 42988, Republic of Korea; SBCure Corp., Daegu, 43017, Republic of Korea
| | - Min Young Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Yu Seon Kim
- Well Aging Research Center, DGIST, Daegu, 42988, Republic of Korea
| | - Yun Jeoung Mo
- Well Aging Research Center, DGIST, Daegu, 42988, Republic of Korea
| | - Yun-Il Lee
- Well Aging Research Center, DGIST, Daegu, 42988, Republic of Korea
| | - Minseok S Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea; CTCELLS Corp., Daegu, 42988, Republic of Korea; Translational Responsive Medicine Center (TRMC), DGIST, Daegu, 42988, Republic of Korea; New Biology Research Center (NBRC), DGIST, Daegu, 42988, Republic of Korea.
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4
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Fan Z, Wen X, Ding X, Wang Q, Wang S, Yu W. Advances in biotechnology and clinical therapy in the field of peripheral nerve regeneration based on magnetism. Front Neurol 2023; 14:1079757. [PMID: 36970536 PMCID: PMC10036769 DOI: 10.3389/fneur.2023.1079757] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/07/2023] [Indexed: 03/12/2023] Open
Abstract
Peripheral nerve injury (PNI) is one of the most common neurological diseases. Recent studies on nerve cells have provided new ideas for the regeneration of peripheral nerves and treatment of physical trauma or degenerative disease-induced loss of sensory and motor neuron functions. Accumulating evidence suggested that magnetic fields might have a significant impact on the growth of nerve cells. Studies have investigated different magnetic field properties (static or pulsed magnetic field) and intensities, various magnetic nanoparticle-encapsulating cytokines based on superparamagnetism, magnetically functionalized nanofibers, and their relevant mechanisms and clinical applications. This review provides an overview of these aspects as well as their future developmental prospects in related fields.
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Low-intensity pulsed ultrasound promotes proliferation and myelinating genes expression of Schwann cells through NRG1/ErbB signaling pathway. Tissue Cell 2023; 80:101985. [PMID: 36459840 DOI: 10.1016/j.tice.2022.101985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022]
Abstract
Schwann cells (SCs) are the major component of myelin sheath in the peripheral nervous system, which are necessary in the development, function maintenance, and repair of peripheral nerves. This study aimed to investigate the potential mechanism of low-intensity pulsed ultrasound (LIPUS) affecting the proliferation and myelinating activity of SCs. Rat Schwann cell line RSC96 were cultured and exposed to LIPUS of different duty ratios (control, 20 %, 50 %, 80 %). Results demonstrated that LIPUS with a duty ratio of 50 % showing the maximal effect in facilitating proliferation of SCs. The expressions of Krox20 and myelin basic protein (MBP), the key molecules of SC myelination, and the potent inducer of myelination neuregulin 1 (NRG1) and its receptors ErbB2 and ErbB3 increased significantly by LIPUS. The reaction of these factors to LIPUS were both time- and duty ratio-dependent: namely LIPUS with higher duty ratios took effects when applied repeatedly over more consecutive days. These observations indicated that NRG1/ErbB signaling pathway might contribute to the effects of LIPUS on the proliferation and myelinating status of SCs, which could be one of the mechanisms in the protective role of LIPUS in nerve repair and regeneration. Our work provided novel insights for promising strategies of nerve repair therapy.
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Manganas P, Kavatzikidou P, Kordas A, Babaliari E, Stratakis E, Ranella A. The role of mechanobiology on the Schwann cell response: A tissue engineering perspective. Front Cell Neurosci 2022; 16:948454. [PMID: 36035260 PMCID: PMC9399718 DOI: 10.3389/fncel.2022.948454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Schwann cells (SCs), the glial cells of the peripheral nervous system (PNS), do not only form myelin sheaths thereby insulating the electrical signal propagated by the axons, but also play an essential role in the regeneration of injured axons. SCs are inextricably connected with their extracellular environment and the mechanical stimuli that are received determine their response during development, myelination and injuries. To this end, the mechanobiological response of SCs is being actively researched, as it can determine the suitability of fabricated scaffolds for tissue engineering and regenerative medicine applications. There is growing evidence that SCs are sensitive to changes in the mechanical properties of the surrounding environment (such as the type of material, its elasticity and stiffness), different topographical features provided by the environment, as well as shear stress. In this review, we explore how different mechanical stimuli affect SC behaviour and highlight the importance of exploring many different avenues when designing scaffolds for the repair of PNS injuries.
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Affiliation(s)
- Phanee Manganas
- Tissue Engineering, Regenerative Medicine and Immunoengineering Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
| | - Paraskevi Kavatzikidou
- Tissue Engineering, Regenerative Medicine and Immunoengineering Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
- Ultrafast Laser Micro and Nano Processing Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
| | - Antonis Kordas
- Tissue Engineering, Regenerative Medicine and Immunoengineering Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
- Department of Materials Science and Technology, University of Crete, Heraklion, Greece
| | - Eleftheria Babaliari
- Tissue Engineering, Regenerative Medicine and Immunoengineering Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
- Ultrafast Laser Micro and Nano Processing Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
| | - Emmanuel Stratakis
- Ultrafast Laser Micro and Nano Processing Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
| | - Anthi Ranella
- Tissue Engineering, Regenerative Medicine and Immunoengineering Laboratory, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), Heraklion, Greece
- *Correspondence: Anthi Ranella
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7
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Kourtidou-Papadeli C, Frantzidis CA, Bakirtzis C, Petridou A, Gilou S, Karkala A, Machairas I, Kantouris N, Nday CM, Dermitzakis EV, Bakas E, Mougios V, Bamidis PD, Vernikos J. Therapeutic Benefits of Short-Arm Human Centrifugation in Multiple Sclerosis-A New Approach. Front Neurol 2022; 12:746832. [PMID: 35058870 PMCID: PMC8764123 DOI: 10.3389/fneur.2021.746832] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/03/2021] [Indexed: 12/16/2022] Open
Abstract
Short-arm human centrifugation (SAHC) is proposed as a robust countermeasure to treat deconditioning and prevent progressive disability in a case of secondary progressive multiple sclerosis. Based on long-term physiological knowledge derived from space medicine and missions, artificial gravity training seems to be a promising physical rehabilitation approach toward the prevention of musculoskeletal decrement due to confinement and inactivity. So, the present study proposes a novel infrastructure based on SAHC to investigate the hypothesis that artificial gravity ameliorates the degree of disability. The patient was submitted to a 4-week training programme including three weekly sessions of 30 min of intermittent centrifugation at 1.5–2 g. During sessions, cardiovascular, muscle oxygen saturation (SmO2) and electroencephalographic (EEG) responses were monitored, whereas neurological and physical performance tests were carried out before and after the intervention. Cardiovascular parameters improved in a way reminiscent of adaptations to aerobic exercise. SmO2 decreased during sessions concomitant with increased g load, and, as training progressed, SmO2 of the suffering limb dropped, both effects suggesting increased oxygen use, similar to that seen during hard exercise. EEG showed increased slow and decreased fast brain waves, with brain reorganization/plasticity evidenced through functional connectivity alterations. Multiple-sclerosis-related disability and balance capacity also improved. Overall, this study provides novel evidence supporting SAHC as a promising therapeutic strategy in multiple sclerosis, based on mechanical loading, thereby setting the basis for future randomized controlled trials.
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Affiliation(s)
- Chrysoula Kourtidou-Papadeli
- Biomedical Engineering and Aerospace Neuroscience (BEAN), Laboratory of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.,Greek Aerospace Medical Association and Space Research (GASMA-SR), Thessaloniki, Greece.,Laboratory of Aerospace and Rehabilitation Applications "Joan Vernikos", AROGI Rehabilitation Centre, Thessaloniki, Greece.,Aeromedical Center of Thessaloniki (AeMC), Thessaloniki, Greece
| | - Christos A Frantzidis
- Biomedical Engineering and Aerospace Neuroscience (BEAN), Laboratory of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.,Greek Aerospace Medical Association and Space Research (GASMA-SR), Thessaloniki, Greece
| | - Christos Bakirtzis
- Department of Neurology, Multiple Sclerosis Center, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Anatoli Petridou
- Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Sotiria Gilou
- Biomedical Engineering and Aerospace Neuroscience (BEAN), Laboratory of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Aliki Karkala
- Greek Aerospace Medical Association and Space Research (GASMA-SR), Thessaloniki, Greece
| | - Ilias Machairas
- Biomedical Engineering and Aerospace Neuroscience (BEAN), Laboratory of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Nikolaos Kantouris
- Greek Aerospace Medical Association and Space Research (GASMA-SR), Thessaloniki, Greece
| | - Christiane M Nday
- Biomedical Engineering and Aerospace Neuroscience (BEAN), Laboratory of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Eleftherios Bakas
- Laboratory of Aerospace and Rehabilitation Applications "Joan Vernikos", AROGI Rehabilitation Centre, Thessaloniki, Greece
| | - Vassilis Mougios
- Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Panagiotis D Bamidis
- Biomedical Engineering and Aerospace Neuroscience (BEAN), Laboratory of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.,Greek Aerospace Medical Association and Space Research (GASMA-SR), Thessaloniki, Greece
| | - Joan Vernikos
- Greek Aerospace Medical Association and Space Research (GASMA-SR), Thessaloniki, Greece.,Thirdage LLC, Culpeper, VA, United States
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Kim JS, Shah GM, Chae YJ, Hwang JS, Ahn JM, Gong HS. Ulnar nerve morphology on magnetic resonance imaging predicts nerve recovery after surgery for cubital tunnel syndrome. HAND SURGERY & REHABILITATION 2021; 41:90-95. [PMID: 34763114 DOI: 10.1016/j.hansur.2021.10.316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/19/2021] [Accepted: 10/25/2021] [Indexed: 10/19/2022]
Abstract
Magnetic resonance imaging (MRI) can evaluate nerve morphology in cubital tunnel syndrome (CuTS), but its value in predicting surgical outcome is unclear. The purpose of this study was to determine whether ulnar nerve morphology on MRI correlated with outcome after CuTS surgery. We reviewed 40 patients who had preoperative MRI and electrodiagnostic (EDX) examinations for CuTS and outcome evaluation 6 months and 2 years postoperatively. Using MRI, ulnar nerve cross-sectional area (UNCSA), changes in signal intensity, and any space-occupying lesion were evaluated. Other factors assessed were age, symptom duration and severity, type-2 diabetes and EDX parameters. Factors associated with unfavorable surgical outcome were identified. At 6 months postoperatively, 12 patients (30%) had excellent, 19 (47.5%) good, 8 (20%) fair and 1 (2.5%) poor results on modified Wilson-Krout criteria. On univariate analysis, unfavorable outcomes were associated with increased UNCSA, space-occupying lesion, and decreased motor nerve conduction velocity (mNCV), and on multivariate analysis with increased UNCSA 1 cm distal from the epicondyle only (model 1) or increased UNCSA 1 cm proximal from the epicondyle and decreased mNCV (model 2). At 2 years, 15 patients (37.5%) had excellent, 21 (52.5%) good, 3 (7.5%) fair and 1 (2.5%) poor results, and no factors correlated with unfavorable outcome. Increased UNCSA on MRI was associated with unfavorable outcome at 6 months but not at 2 years. This study suggests that morphologic ulnar nerve changes can predict delayed nerve recovery after surgery for CuTS.
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Affiliation(s)
- J S Kim
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea
| | - G M Shah
- Department of Orthopedics and Trauma Surgery, Patan Academy of Health Sciences, Lagankhel-5, 44700 Bagmati, Nepal
| | - Y J Chae
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea
| | - J S Hwang
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea.
| | - J M Ahn
- Department of Radiology, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea
| | - H S Gong
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea.
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9
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Ding YQ, Qi JG. Sensory root demyelination: Transforming touch into pain. Glia 2021; 70:397-413. [PMID: 34549463 DOI: 10.1002/glia.24097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 11/12/2022]
Abstract
The normal feeling of touch is vital for nearly every aspect of our daily life. However, touching is not always felt as touch, but also abnormally as pain under numerous diseased conditions. For either mechanistic understanding of the faithful feeling of touch or clinical management of chronic pain, there is an essential need to thoroughly dissect the neuropathological changes that lead to painful touch or tactile allodynia and their corresponding cellular and molecular underpinnings. In recent years, we have seen remarkable progress in our understanding of the neural circuits for painful touch, with an increasing emphasis on the upstream roles of non-neuronal cells. As a highly specialized form of axon ensheathment by glial cells in jawed vertebrates, myelin sheaths not only mediate their outstanding neural functions via saltatory impulse propagation of temporal and spatial precision, but also support long-term neuronal/axonal integrity via metabolic and neurotrophic coupling. Therefore, myelinopathies have been implicated in diverse neuropsychiatric diseases, which are traditionally recognized as a result of the dysfunctions of neural circuits. However, whether myelinopathies can transform touch into pain remains a long-standing question. By summarizing and reframing the fragmentary but accumulating evidence so far, the present review indicates that sensory root demyelination represents a hitherto underappreciated neuropathological change for most neuropathic conditions of painful touch and offers an insightful window into faithful tactile sensation as well as a potential therapeutic target for intractable painful touch.
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Affiliation(s)
- You-Quan Ding
- Department of Histology, Embryology and Neurobiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Jian-Guo Qi
- Department of Histology, Embryology and Neurobiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
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Hsiao MY, Wu YW, Chen WS, Lin YL, Kuo PL, Wu CH. Pathogenic Hydrogel? A Novel-Entrapment Neuropathy Model Induced by Ultrasound-Guided Perineural Injections. Int J Mol Sci 2021; 22:ijms22073494. [PMID: 33800600 PMCID: PMC8036453 DOI: 10.3390/ijms22073494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 12/20/2022] Open
Abstract
Entrapment neuropathy (EN) is a prevalent and debilitative condition caused by a complex pathogenesis that involves a chronic compression–edema–ischemia cascade and perineural adhesion that results in excessive shear stress during motion. Despite decades of research, an easily accessible and surgery-free animal model mimicking the mixed etiology is currently lacking, thus limiting our understanding of the disease and the development of effective therapies. In this proof-of-concept study, we used ultrasound-guided perineural injection of a methoxy poly(ethylene glycol)-b-Poly(lactide-co-glycoilide) carboxylic acid (mPEG-PLGA-BOX) hydrogel near the rat’s sciatic nerve to induce EN, as confirmed sonographically, electrophysiologically, and histologically. The nerve that was injected with hydrogel appeared unevenly contoured and swollen proximally with slowed nerve conduction velocities across the injected segments, thus showing the compressive features of EN. Histology showed perineural cellular infiltration, deposition of irregular collagen fibers, and a possible early demyelination process, thus indicating the existence of adhesions. The novel method provides a surgery-free and cost-effective way to establish a small-animal model of EN that has mixed compression and adhesion features, thus facilitating the additional elucidation of the pathophysiology of EN and the search for promising treatments.
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Affiliation(s)
- Ming-Yen Hsiao
- Department of Physical Medicine and Rehabilitation, College of Medicine, National Taiwan University, Taipei 10048, Taiwan; (M.-Y.H.); (W.-S.C.); (Y.-L.L.)
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei 10048, Taiwan; (Y.-W.W.); (P.L.-K.)
| | - Ya-Wen Wu
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei 10048, Taiwan; (Y.-W.W.); (P.L.-K.)
| | - Wen-Shiang Chen
- Department of Physical Medicine and Rehabilitation, College of Medicine, National Taiwan University, Taipei 10048, Taiwan; (M.-Y.H.); (W.-S.C.); (Y.-L.L.)
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei 10048, Taiwan; (Y.-W.W.); (P.L.-K.)
| | - Yu-Ling Lin
- Department of Physical Medicine and Rehabilitation, College of Medicine, National Taiwan University, Taipei 10048, Taiwan; (M.-Y.H.); (W.-S.C.); (Y.-L.L.)
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei 10048, Taiwan; (Y.-W.W.); (P.L.-K.)
| | - Po-Ling Kuo
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei 10048, Taiwan; (Y.-W.W.); (P.L.-K.)
- Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Chueh-Hung Wu
- Department of Physical Medicine and Rehabilitation, College of Medicine, National Taiwan University, Taipei 10048, Taiwan; (M.-Y.H.); (W.-S.C.); (Y.-L.L.)
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei 10048, Taiwan; (Y.-W.W.); (P.L.-K.)
- Department of Physical Medicine & Rehabilitation, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu 302058, Taiwan
- Correspondence:
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11
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Ginsenoside Compound K Promotes Proliferation, Migration and Differentiation of Schwann Cells via the Activation of MEK/ERK1/2 and PI3K/AKT Pathways. Neurochem Res 2021; 46:1400-1409. [PMID: 33738663 DOI: 10.1007/s11064-021-03279-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/29/2021] [Accepted: 02/19/2021] [Indexed: 12/17/2022]
Abstract
The proliferation and differentiation of Schwann cells are critical for the remyelination of injured peripheral nerve. Ginsenoside compound K (CK) is a metabolite produced from ginsenoside Rb1 which has strong anti-inflammatory effects. However, the potential effects of CK on Schwann cells have not been studied systematically before. Therefore, this study was aimed to explore the functions of CK in Schwann cell proliferation, migration and differentiation and its potential regulatory mechanism. Primary Schwann cells and RSC96 cells were treated with or without CK at different doses. The proliferation and migration of primary Schwann cells and RSC96 cells were examined by Cell Counting Kit-8 (CCK-8) and Transwell assays, respectively. The mRNA expression of myelin-associated glycoprotein (MAG) and myelin basic protein (MBP) was tested by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of all proteins were examined by Western blot. CK could promote cell proliferation, migration and induce MAG and MBP expression in primary Schwann cells and RSC96 cells. Furthermore, CK activated MEK/ERK1/2 and PI3K/AKT pathways, and the beneficial effects of CK on primary Schwann cells and RSC96 cells were distinctly suppressed by inhibitor PD98059 or LY294002. Ginsenoside compound K induced cell proliferation, migration and differentiation via the activation of MEK/ERK1/2 and PI3K/AKT pathways in cultured primary Schwann cells and RSC96 cells.
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Babaliari E, Kavatzikidou P, Mitraki A, Papaharilaou Y, Ranella A, Stratakis E. Combined effect of shear stress and laser-patterned topography on Schwann cell outgrowth: synergistic or antagonistic? Biomater Sci 2021; 9:1334-1344. [PMID: 33367414 DOI: 10.1039/d0bm01218a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Although the peripheral nervous system exhibits a higher rate of regeneration than that of the central nervous system through a spontaneous regeneration after injury, the functional recovery is fairly infrequent and misdirected. Thus, the development of successful methods to guide neuronal outgrowth, in vitro, is of great importance. In this study, a precise flow controlled microfluidic system with specific custom-designed chambers, incorporating laser-microstructured polyethylene terephthalate (PET) substrates comprising microgrooves, was fabricated to assess the combined effect of shear stress and topography on Schwann cells' behavior. The microgrooves were positioned either parallel or perpendicular to the direction of the flow inside the chambers. Additionally, the cell culture results were combined with computational flow simulations to calculate accurately the shear stress values. Our results demonstrated that wall shear stress gradients may be acting either synergistically or antagonistically depending on the substrate groove orientation relative to the flow direction. The ability to control cell alignment in vitro could potentially be used in the fields of neural tissue engineering and regenerative medicine.
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Affiliation(s)
- Eleftheria Babaliari
- Foundation for Research and Technology - Hellas (F.O.R.T.H.), Institute of Electronic Structure and Laser (I.E.S.L.) Vassilika Vouton, 70013 Heraklion, Greece.
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13
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Ning L, Gil CJ, Hwang B, Theus AS, Perez L, Tomov ML, Bauser-Heaton H, Serpooshan V. Biomechanical factors in three-dimensional tissue bioprinting. APPLIED PHYSICS REVIEWS 2020; 7:041319. [PMID: 33425087 PMCID: PMC7780402 DOI: 10.1063/5.0023206] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/23/2020] [Indexed: 05/07/2023]
Abstract
3D bioprinting techniques have shown great promise in various fields of tissue engineering and regenerative medicine. Yet, creating a tissue construct that faithfully represents the tightly regulated composition, microenvironment, and function of native tissues is still challenging. Among various factors, biomechanics of bioprinting processes play fundamental roles in determining the ultimate outcome of manufactured constructs. This review provides a comprehensive and detailed overview on various biomechanical factors involved in tissue bioprinting, including those involved in pre, during, and post printing procedures. In preprinting processes, factors including viscosity, osmotic pressure, and injectability are reviewed and their influence on cell behavior during the bioink preparation is discussed, providing a basic guidance for the selection and optimization of bioinks. In during bioprinting processes, we review the key characteristics that determine the success of tissue manufacturing, including the rheological properties and surface tension of the bioink, printing flow rate control, process-induced mechanical forces, and the in situ cross-linking mechanisms. Advanced bioprinting techniques, including embedded and multi-material printing, are explored. For post printing steps, general techniques and equipment that are used for characterizing the biomechanical properties of printed tissue constructs are reviewed. Furthermore, the biomechanical interactions between printed constructs and various tissue/cell types are elaborated for both in vitro and in vivo applications. The review is concluded with an outlook regarding the significance of biomechanical processes in tissue bioprinting, presenting future directions to address some of the key challenges faced by the bioprinting community.
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Affiliation(s)
- Liqun Ning
- Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, Georgia 30322, USA
| | - Carmen J. Gil
- Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, Georgia 30322, USA
| | - Boeun Hwang
- Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, Georgia 30322, USA
| | - Andrea S. Theus
- Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, Georgia 30322, USA
| | - Lilanni Perez
- Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, Georgia 30322, USA
| | - Martin L. Tomov
- Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, Georgia 30322, USA
| | - Holly Bauser-Heaton
- Authors to whom correspondence should be addressed:. Telephone: 404-712-9717. Fax: 404-727-9873
| | - Vahid Serpooshan
- Authors to whom correspondence should be addressed:. Telephone: 404-712-9717. Fax: 404-727-9873
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Xia B, Gao J, Li S, Huang L, Zhu L, Ma T, Zhao L, Yang Y, Luo K, Shi X, Mei L, Zhang H, Zheng Y, Lu L, Luo Z, Huang J. Mechanical stimulation of Schwann cells promote peripheral nerve regeneration via extracellular vesicle-mediated transfer of microRNA 23b-3p. Theranostics 2020; 10:8974-8995. [PMID: 32802175 PMCID: PMC7415818 DOI: 10.7150/thno.44912] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/09/2020] [Indexed: 12/14/2022] Open
Abstract
Rationale: Peripheral nerves are unique in their remarkable elasticity. Schwann cells (SCs), important components of the peripheral nervous system (PNS), are constantly subjected to physiological and mechanical stresses from dynamic stretching and compression forces during movement. So far, it is not clear if SCs sense and respond to mechanical signals. It is also unknown whether mechanical stimuli can interfere with the intercellular communications between neurons and SCs, and what role extracellular vesicles (EVs) play in this process. The present study aimed to examine the effect of mechanical stimuli on the EV-mediated intercellular communication between neurons and SCs, explore their effect on axonal regeneration, and investigate the underlying mechanism. Methods: Purified SCs were stimulated using a magnetic force-based mechanical stimulation (MS) system and EVs were purified from mechanically stimulated SCs (MS-SCs-EVs) and non-stimulated SCs (SCs-EVs). The effect of MS-SCs-EVs on axonal elongation was examined in vitro and in vivo. High throughput miRNA sequencing was performed to compare the differential miRNA profiles between MS-SCs-EVs and SCs-EVs. The functional role of differentially expressed miRNAs on neurite extension in MS-SCs-EVs was examined. Also, the putative target genes of differentially expressed miRNAs in MS-SCs-EVs were predicted by bioinformatics tools, and the regulatory effect of those miRNAs on putative target genes was validated both in vitro and in vivo. Results: The MS-SCs-EVs showed an average size of 137.52±1.77 nm, and could be internalized by dorsal root ganglion (DRG) neurons. Compared to SCs-EVs, MS-SCs-EVs showed a stronger ability to enhance neurite outgrowth in vitro and nerve regeneration in vivo. High throughput miRNA sequencing identified a number of differentially expressed miRNAs in MS-SCs-EVs. Further analysis of those EV-miRNAs demonstrated that miR-23b-3p played a predominant role in MS-SCs-EVs since its deprivation abolished their enhanced axonal elongation. Furthermore, we identified neuropilin 1 (Nrp1) in neurons as the target gene of miR-23b-3p in MS-SCs-EVs. This observation was supported by the evidence that miR-23b-3p could decrease Nrp1-3'-UTR-WT luciferase activity in vitro and down-regulate Nrp1 expression in neurons. Conclusion: Our findings suggested that mechanical stimuli are capable of modulating the intercellular communication between neurons and SCs by altering miRNA composition in MS-SCs-EVs. Transfer of miR-23b-3p by MS-SCs-EVs from mechanically stimulated SCs to neurons decreased neuronal Nrp1 expression, which was responsible, at least in part, for the beneficial effect of MS-SCs-EVs on axonal regeneration. Our results highlighted the potential therapeutic value of MS-SCs-EVs and miR-23b-3p-enriched EVs in peripheral nerve injury repair.
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Affiliation(s)
- Bing Xia
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Jianbo Gao
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Shengyou Li
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Liangliang Huang
- Department of Orthopedics, the General Hospital of Central Theater Command of People's Liberation Army, Wuhan, 430070, People's Republic of China
| | - Lei Zhu
- Department of Spine Surgery, Honghui Hospital Affiliated to Medical School of Xi'an Jiaotong University, Xi'an Shaanxi, 710054, People's Republic of China
| | - Teng Ma
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Laihe Zhao
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Yujie Yang
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Kai Luo
- Department of Orthopedics, the 985th Hospital People's Liberation Army Joint Logistics Support Force, Taiyuan, 030000, People's Republic of China
| | - Xiaowei Shi
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Liangwei Mei
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Hao Zhang
- Department of Spinal Surgery, the People's Hospital of Longhua District, Shenzhen, 518109, People's Republic of China
| | - Yi Zheng
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Lei Lu
- Department of Oral Anatomy and Physiology, State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, School of Stomatology, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Zhuojing Luo
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Jinghui Huang
- Department of Orthopedics, Xijing Hospital, the Fourth Military Medical University, Xi'an, 710032, People's Republic of China
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Grossemy S, Chan PP, Doran PM. Stimulation of cell growth and neurogenesis using protein-functionalized microfibrous scaffolds and fluid flow in bioreactors. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Losurdo M, Davidsson J, Sköld MK. Diffuse Axonal Injury in the Rat Brain: Axonal Injury and Oligodendrocyte Activity Following Rotational Injury. Brain Sci 2020; 10:E229. [PMID: 32290212 PMCID: PMC7225974 DOI: 10.3390/brainsci10040229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 02/06/2023] Open
Abstract
Traumatic brain injury (TBI) commonly results in primary diffuse axonal injury (DAI) and associated secondary injuries that evolve through a cascade of pathological mechanisms. We aim at assessing how myelin and oligodendrocytes react to head angular-acceleration-induced TBI in a previously described model. This model induces axonal injuries visible by amyloid precursor protein (APP) expression, predominantly in the corpus callosum and its borders. Brain tissue from a total of 27 adult rats was collected at 24 h, 72 h and 7 d post-injury. Coronal sections were prepared for immunohistochemistry and RNAscope® to investigate DAI and myelin changes (APP, MBP, Rip), oligodendrocyte lineage cell loss (Olig2), oligodendrocyte progenitor cells (OPCs) (NG2, PDGFRa) and neuronal stress (HSP70, ATF3). Oligodendrocytes and OPCs numbers (expressed as percentage of positive cells out of total number of cells) were measured in areas with high APP expression. Results showed non-statistically significant trends with a decrease in oligodendrocyte lineage cells and an increase in OPCs. Levels of myelination were mostly unaltered, although Rip expression differed significantly between sham and injured animals in the frontal brain. Neuronal stress markers were induced at the dorsal cortex and habenular nuclei. We conclude that rotational injury induces DAI and neuronal stress in specific areas. We noticed indications of oligodendrocyte death and regeneration without statistically significant changes at the timepoints measured, despite indications of axonal injuries and neuronal stress. This might suggest that oligodendrocytes are robust enough to withstand this kind of trauma, knowledge important for the understanding of thresholds for cell injury and post-traumatic recovery potential.
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Affiliation(s)
- Michela Losurdo
- Department of Neuroscience, Karolinska Institute, 171 77 Stockholm, Sweden;
- Department of Molecular Medicine, Università degli Studi di Pavia, 27100 Pavia, Italy
| | - Johan Davidsson
- Department of Mechanics and Maritime Sciences, Chalmers University of Technology, 412 96 Gothenburg, Sweden;
| | - Mattias K. Sköld
- Department of Neuroscience, Karolinska Institute, 171 77 Stockholm, Sweden;
- Department of Neuroscience, Section of Neurosurgery, Uppsala University, 751 85 Uppsala, Sweden
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17
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Coupling in vitro cell culture with synchrotron SAXS to understand the bio-interaction of lipid-based liquid crystalline nanoparticles with vascular endothelial cells. Drug Deliv Transl Res 2020; 10:610-620. [DOI: 10.1007/s13346-020-00718-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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Chen M, Song H, Cui J, Johnson CE, Hubler GK, DePalma RG, Gu Z, Xia W. Proteomic Profiling of Mouse Brains Exposed to Blast-Induced Mild Traumatic Brain Injury Reveals Changes in Axonal Proteins and Phosphorylated Tau. J Alzheimers Dis 2019; 66:751-773. [PMID: 30347620 DOI: 10.3233/jad-180726] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD), the most prevalent form of dementia, is characterized by two pathological hallmarks: Tau-containing neurofibrillary tangles and amyloid-β protein (Aβ)-containing neuritic plaques. The goal of this study is to understand mild traumatic brain injury (mTBI)-related brain proteomic changes and tau-related biochemical adaptations that may contribute to AD-like neurodegeneration. We found that both phosphorylated tau (p-tau) and the ratio of p-tau/tau were significantly increased in brains of mice collected at 3 and 24 h after exposure to 82-kPa low-intensity open-field blast. Neurological deficits were observed in animals at 24 h and 7 days after the blast using Simple Neuroassessment of Asymmetric imPairment (SNAP) test, and axon/dendrite degeneration was revealed at 7 days by silver staining. Liquid chromatography-mass spectrometry (LC-MS/MS) was used to analyze brain tissue labeled with isobaric mass tags for relative protein quantification. The results from the proteomics and bioinformatic analysis illustrated the alterations of axonal and synaptic proteins in related pathways, including but not being limited to substantia nigra development, cortical cytoskeleton organization, and synaptic vesicle exocytosis, suggesting a potential axonal damage caused by blast-induced mTBI. Among altered proteins found in brains suffering blast, microtubule-associated protein 1B, stathmin, neurofilaments, actin binding proteins, myelin basic protein, calcium/calmodulin-dependent protein kinase, and synaptotagmin I were representative ones involved in altered pathways elicited by mTBI. Therefore, TBI induces elevated phospho-tau, a pathological feature found in brains of AD, and altered a number of neurophysiological processes, supporting the notion that blast-induced mTBI as a risk factor contributes to AD pathogenesis. LC/MS-based profiling has presented candidate target/pathways that could be explored for future therapeutic development.
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Affiliation(s)
- Mei Chen
- Geriatric Research Education and Clinical Center, Office of Research and Development, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, USA.,Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Hailong Song
- Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, USA.,Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jiankun Cui
- Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, USA.,Truman VA Hospital Research Service, Columbia, MO, USA
| | - Catherine E Johnson
- Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, Rolla, MO, USA
| | - Graham K Hubler
- Sidney Kimmel Institute for Nuclear Renaissance, Department of Physics and Astronomy, University of Missouri, Columbia, MO USA
| | - Ralph G DePalma
- Office of Research and Development, Department of Veterans Affairs, Washington, DC, USA Department of Surgery, Uniformed University of the Health Science, Bethesda, MD, USA
| | - Zezong Gu
- Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, USA.,Truman VA Hospital Research Service, Columbia, MO, USA
| | - Weiming Xia
- Geriatric Research Education and Clinical Center, Office of Research and Development, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, USA.,Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
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19
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Modrak M, Sundem L, Gupta R, Zuscik MJ, Elfar J. Pharmacological Attenuation of Electrical Effects in a Model of Compression Neuropathy. J Bone Joint Surg Am 2019; 101:523-530. [PMID: 30893233 PMCID: PMC6738556 DOI: 10.2106/jbjs.18.00162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Peripheral nerve compression and entrapment can be debilitating. Using a validated animal model of peripheral nerve compression, we examined the utility of 2 drugs approved for other uses in humans, 4-aminopyridine (4-AP) and erythropoietin (EPO), as treatments for surgically induced ischemia and as adjuvants to surgical decompression. METHODS Peripheral nerve compression was induced in wild-type mice by placing an inert silicone sleeve around the sciatic nerve. Decompression surgery was performed at 6 weeks with mice receiving 4-AP, EPO, or saline solution either during and after compression or only after decompression. A nerve conduction study and morphometric analyses were performed to compare the extent of the injury and the efficacy of the therapies, and the findings were subjected to statistical analysis. RESULTS During peripheral nerve compression, there was a progressive decline in nerve conduction velocity compared with that in sham-treatment animals, in which nerve conduction velocity remained normal (∼55 m/s). Mice treated with 4-AP or EPO during the compression phase had significantly smaller declines in nerve conduction velocity and increased plateau nerve conduction velocities compared with untreated controls (animals that received saline solution). Histomorphometric analyses of newly decompressed nerves (i.e., nerves that underwent decompression on the day that the mouse was sacrificed) revealed that both treated groups had significantly greater proportions of large (>5-µm) axons than the untreated controls. Following surgical decompression, all animals recovered to a normal baseline nerve conduction velocity by day 15; however, treatment significantly accelerated improvement (in both the 4-AP and the EPO group), even when it was only started after decompression. Histomorphometric analyses at 7 and 15 days following surgical decompression revealed significantly increased myelin thickness and significantly greater proportions of large axons among the treated animals. CONCLUSIONS Both the 4-AP and the EPO-treated group demonstrated improvements in tissue architectural and electrodiagnostic measurements, both during and after peripheral nerve compression, compared with untreated mice. CLINICAL RELEVANCE Peripheral nerve decompression is one of the most commonly performed procedures in orthopaedic surgery. We believe that there is reason for some optimism about the translation of our findings to the clinical setting. Our findings in this murine model suggest that 4-AP and EPO may lessen the effects of nerve entrapment and that the use of these agents after decompression may speed and perhaps otherwise optimize recovery after surgery.
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Affiliation(s)
- Maxwell Modrak
- School of Medicine and Dentistry, University of Rochester, Rochester, New York
| | - Leigh Sundem
- School of Medicine and Dentistry, University of Rochester, Rochester, New York
| | - Ranjan Gupta
- Department of Orthopaedic Surgery, University of California at Irvine, Irvine, California
| | - Michael J. Zuscik
- Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, New York
| | - John Elfar
- Department of Orthopaedics and Rehabilitation, Center for Orthopaedic Research and Translational Science, The Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
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20
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Orgel J, Madhurapantula RS, Eidsmore A, Wang M, Dutov P, Modrich CD, Antipova O, McDonald J, Satapathy S. X-ray diffraction reveals blunt-force loading threshold for nanoscopic structural change in ex vivo neuronal tissues. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:89-95. [PMID: 30655472 PMCID: PMC6337887 DOI: 10.1107/s1600577518015035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/23/2018] [Indexed: 06/09/2023]
Abstract
An ex vivo blunt-force loading experiment is reported that may, in the future, provide insight into the molecular structural changes occurring in load-induced conditions such as traumatic brain injury (TBI). TBI appears to manifest in changes in multiple structures and elements within the brain and nervous system. Individuals with a TBI may suffer from cognitive and/or behavioral impairments which can adversely affect their quality of life. Information on the injury threshold of tissue loading for mammalian neurons is critical in the development of a quantified neuronal-level dose-response model. Such a model could aid in the discovery of enhanced methods for TBI detection, treatment and prevention. Currently, thresholds of mechanical load leading to direct force-coupled nanostructural changes in neurons are unknown. In this study, we make use of the fact that changes in the structure and periodicity of myelin may indicate neurological damage and can be detected with X-ray diffraction (XRD). XRD allows access to a nanoscopic resolution range not readily achieved by alternative methods, nor does the experimental methodology require chemical sample fixation. In this study, XRD was used to evaluate the affects of controlled mechanical loading on myelin packing structure in ex vivo optic nerve samples. By using a series of crush tests on isolated optic nerves a quantified baseline for mechanical load was found to induce changes in the packing structure of myelin. To the authors' knowledge, this is the first report of its kind.
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Affiliation(s)
- Joseph Orgel
- Departments of Biology, Physics and Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Rama S. Madhurapantula
- Departments of Biology, Physics and Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Ashley Eidsmore
- Weapons and Materials Research Directorate, Army Research Laboratory, USA
| | - Meng Wang
- Departments of Biology, Physics and Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Pavel Dutov
- Departments of Biology, Physics and Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Charles D. Modrich
- Departments of Biology, Physics and Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Olga Antipova
- X-ray Science Division, Argonne National Laboratory, Chicago, IL, USA
| | - Jason McDonald
- Weapons and Materials Research Directorate, Army Research Laboratory, USA
| | - Sikhanda Satapathy
- Weapons and Materials Research Directorate, Army Research Laboratory, USA
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21
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Wang J, Tian L, Luo B, Ramakrishna S, Kai D, Loh XJ, Yang IH, Deen GR, Mo X. Engineering PCL/lignin nanofibers as an antioxidant scaffold for the growth of neuron and Schwann cell. Colloids Surf B Biointerfaces 2018; 169:356-365. [PMID: 29803151 DOI: 10.1016/j.colsurfb.2018.05.021] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/28/2018] [Accepted: 05/09/2018] [Indexed: 01/30/2023]
Abstract
Antioxidant is critical for the successful of nerve tissue regeneration, and biomaterials with antioxidant activity might be favorable for peripheral nerve repair. Lignin, a biopolymer from wood with excellent antioxidant properties, is still "unexplored" as biomaterials. To design an antioxidative bioscaffold for nerve regeneration, here we synthesized lignin-polycaprolactone (PCL) copolymers via solvent free ring-opening polymerization (ROP). Then such lignin-PCL copolymers were incorporated with PCL and engineered into nanofibrous scaffolds for supporting the growth of neuron and Schwann cell. Our results showed that the addition of lignin-PCL enhanced the mechanical properties of PCL nanofibers and endowed them with good antioxidant properties (up to 98.3 ± 1.9% free radical inhibition within 4 h). Cell proliferation assay showed that PCL/lignin-PCL nanofibers increased cell viability compared to PCL fibers, especially after an oxidative challenge. Moreover, Schwann cells and dorsal root ganglion (DRG) neurons cultured on the nanofibers to assess their potential for nerve regeneration. These results suggested that nanofibers with lignin copolymers promoted cell proliferation of both BMSCs and Schwann cells, enhanced myelin basic protein expressions of Schwann cells and stimulated neurite outgrowth of DRG neurons. In all, these sustainable, intrinsically antioxidant nanofibers may be a potential candidate for nerve TE applications.
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Affiliation(s)
- Jing Wang
- State Key Laboratory of Modification of Chemical Fibers and Polymer Materials, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; Center for Nanofibers and Nanotechnology, E3-05-14, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, 117576, Singapore
| | - Lingling Tian
- Center for Nanofibers and Nanotechnology, E3-05-14, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, 117576, Singapore
| | - Baiwen Luo
- Singapore Institute for Neurotechnology, National University of Singapore, 28 Medical Drive, #05-COR, 119077, Singapore
| | - Seeram Ramakrishna
- Center for Nanofibers and Nanotechnology, E3-05-14, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, 117576, Singapore
| | - Dan Kai
- Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way. Innovis, #08-03, 138634, Singapore.
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way. Innovis, #08-03, 138634, Singapore; Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117576, Singapore; Singapore Eye Research Institute, 11 Third Hospital Avenue, 168751, Singapore
| | - In Hong Yang
- Singapore Institute for Neurotechnology, National University of Singapore, 28 Medical Drive, #05-COR, 119077, Singapore
| | - G Roshan Deen
- Soft Materials Laboratory, Natural Sciences and Science Education, National Institute of Education Nanyang Technological University, Singapore
| | - Xiumei Mo
- State Key Laboratory of Modification of Chemical Fibers and Polymer Materials, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China.
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22
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Caro XJ, Galbraith RG, Winter EF. Evidence of peripheral large nerve involvement in fibromyalgia: a retrospective review of EMG and nerve conduction findings in 55 FM subjects. Eur J Rheumatol 2018; 5:104-110. [PMID: 30185358 DOI: 10.5152/eurjrheum.2018.17109] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 09/05/2017] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE Whereas small fiber neuropathy (SFN) is now a recognized part of fibromyalgia (FM), surprisingly little attention has been paid to any findings of large fiber neuropathy (LFN) in this disorder. Since 90% to 95% of FM subjects seen in our outpatient facility routinely undergo EMG and nerve conduction studies (NCS) we elected to retrospectively review the EMG/NCS results garnered from a large cohort of unselected subjects in order to describe the electrodiagnostic features of LFN in FM. METHODS Records from 100 consecutive, unselected clinic patients meeting the 1990 ACR criteria for FM, who had undergone EMG/NCS, were reviewed. The same electromyographer tested all subjects. After exclusion of FM patients with any other clinically relevant condition that might influence EMG results (e.g., familial neural degenerative conditions, diabetes mellitus, Vitamin B-12 deficiency, etc.) fifty-five FM subjects remained: 29 subjects with "FM Only," and 26 subjects with FM+Rheumatoid Arthritis ("FM+RA"). All subjects had also undergone ankle area skin biopsy for determination of epidermal nerve fiber density (ENFD). Fourteen other subjects, without FM or RA, examined by the same electromyographer, were used as an EMG/NCS comparison group. RESULTS Ninety percent of the "FM Only" subjects demonstrated a demyelinating and/or axonal, sensorimotor polyneuropathy, and 63% had findings of SFN (ENFD ≤7 fibers/mm), suggesting a mixed fiber neuropathy in most. Furthermore, 61% of the "FM Only" subjects showed EMG findings suggestive of non-myotomal lower extremity axonal motor denervation, most likely due to a polyneuropathy, and 41% satisfied published criteria for "possible" chronic inflammatory demyelinating polyneuropathy (CIDP). There was surprisingly little difference in the EMG/NCS findings between the "FM Only" and the "FM+RA" groups. With the exception of carpal tunnel syndrome, our EMG/NCS comparison group showed few to none of these findings. CONCLUSION Our review of the EMG/NCS results, gleaned from the largest FM cohort yet studied with these modalities, shows that electrodiagnostic features of polyneuropathy, muscle denervation, and CIDP are common in FM. Furthermore these electrodiagnostic findings are often seen coincident with SFN, and are not significantly influenced by the presence of RA. These results, particularly when taken as a whole, suggest that EMG/NCS may be clinically useful in detecting LFN in FM and help in better understanding the etiopathogenesis of this painful disorder.
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Affiliation(s)
- Xavier J Caro
- Southern California Fibromyalgia Research & Treatment Center, Northridge, California, 91325, USA
| | - Robert G Galbraith
- Southern California Fibromyalgia Research & Treatment Center, Northridge, California, 91325, USA
| | - Earl F Winter
- Southern California Fibromyalgia Research & Treatment Center, Northridge, California, 91325, USA
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Belin S, Zuloaga KL, Poitelon Y. Influence of Mechanical Stimuli on Schwann Cell Biology. Front Cell Neurosci 2017; 11:347. [PMID: 29209171 PMCID: PMC5701625 DOI: 10.3389/fncel.2017.00347] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/19/2017] [Indexed: 12/05/2022] Open
Abstract
Schwann cells are the glial cells of the peripheral nervous system (PNS). They insulate axons by forming a specialized extension of plasma membrane called the myelin sheath. The formation of myelin is essential for the rapid saltatory propagation of action potentials and to maintain the integrity of axons. Although both axonal and extracellular matrix (ECM) signals are necessary for myelination to occur, the cellular and molecular mechanisms regulating myelination continue to be elucidated. Schwann cells in peripheral nerves are physiologically exposed to mechanical stresses (i.e., tensile, compressive and shear strains), occurring during development, adulthood and injuries. In addition, there is a growing body of evidences that Schwann cells are sensitive to the stiffness of their environment. In this review, we detail the mechanical constraints of Schwann cells and peripheral nerves. We explore the regulation of Schwann cell signaling pathways in response to mechanical stimulation. Finally, we provide a comprehensive overview of the experimental studies addressing the mechanobiology of Schwann cells. Understanding which mechanical properties can interfere with the cellular and molecular biology of Schwann cell during development, myelination and following injuries opens new insights in the regulation of PNS development and treatment approaches in peripheral neuropathies.
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Affiliation(s)
- Sophie Belin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
| | - Kristen L. Zuloaga
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
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Ning L, Chen X. A brief review of extrusion-based tissue scaffold bio-printing. Biotechnol J 2017; 12. [PMID: 28544779 DOI: 10.1002/biot.201600671] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/17/2017] [Accepted: 04/19/2017] [Indexed: 01/17/2023]
Abstract
Extrusion-based bio-printing has great potential as a technique for manipulating biomaterials and living cells to create three-dimensional (3D) scaffolds for damaged tissue repair and function restoration. Over the last two decades, advances in both engineering techniques and life sciences have evolved extrusion-based bio-printing from a simple technique to one able to create diverse tissue scaffolds from a wide range of biomaterials and cell types. However, the complexities associated with synthesis of materials for bio-printing and manipulation of multiple materials and cells in bio-printing pose many challenges for scaffold fabrication. This paper presents an overview of extrusion-based bio-printing for scaffold fabrication, focusing on the prior-printing considerations (such as scaffold design and materials/cell synthesis), working principles, comparison to other techniques, and to-date achievements. This paper also briefly reviews the recent development of strategies with regard to hydrogel synthesis, multi-materials/cells manipulation, and process-induced cell damage in extrusion-based bio-printing. The key issue and challenges for extrusion-based bio-printing are also identified and discussed along with recommendations for future, aimed at developing novel biomaterials and bio-printing systems, creating patterned vascular networks within scaffolds, and preserving the cell viability and functions in scaffold bio-printing. The address of these challenges will significantly enhance the capability of extrusion-based bio-printing.
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Affiliation(s)
- Liqun Ning
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Xiongbiao Chen
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada.,Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Canada
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Balikova M, Neklanova M, Sulla I, Hönig M, Halek J, Mihal V, Balik V. Bilateral position-related ulnar neuropathy at elbow in pediatric population and review of the literature. Childs Nerv Syst 2017; 33:399-405. [PMID: 28251323 DOI: 10.1007/s00381-017-3347-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 01/13/2017] [Indexed: 11/30/2022]
Abstract
Perioperative ulnar neuropathies attributed to inappropriate arm positioning and padding during surgical procedures are commonly found in adults. However, their extremely rare incidence in the pediatric population may cause absent awareness of the risk of nerve injury in anesthetized pediatric patients. Furthermore, young patients respond to conservative treatment of neuropathy less favorably than adults and their response also depends on the pathomechanism of the ulnar nerve injury. A surgeon's or anesthetist's failure to recognize all of these specifics in children may result in substantial morbidity of young patients leading to lawsuits. Fortunately, with an adequate knowledge of surgical anatomy and types of procedures and positions in which the ulnar nerve is particularly vulnerable, and familiarity with measures to minimize the potential for neuropathy, this serious complication can be prevented. The aims of this review are to highlight personal experience and current knowledge of the rare position-related ulnar neuropathy, both from a clinical and anatomical-pathophysiological perspective, and to raise awareness about this rare but serious complication in the pediatric population.
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Affiliation(s)
- Mariana Balikova
- Department of Pediatrics, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Marta Neklanova
- Department of Pediatrics, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Igor Sulla
- Department of Surgery, Hospital of Slovak Railways and Institute of Neurobiology, Slovak Academy of Sciences, Soltesovej 4, 040 01, Kosice, Slovak Republic
| | - Martin Hönig
- Neurofyz Ltd., Neurological clinic and EMG laboratory, Prerov, Czech Republic
| | - Jan Halek
- Department of Pediatrics, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Vladimir Mihal
- Department of Pediatrics, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Vladimir Balik
- Department of Neurosurgery, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic.
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Yue Y, Yang X, Zhang L, Xiao X, Nabar NR, Lin Y, Hao L, Zhang D, Huo J, Li J, Cai X, Wang M. Low-intensity pulsed ultrasound upregulates pro-myelination indicators of Schwann cells enhanced by co-culture with adipose-derived stem cells. Cell Prolif 2016; 49:720-728. [PMID: 27625295 PMCID: PMC6496622 DOI: 10.1111/cpr.12298] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/24/2016] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVES Peripheral nerve injuries are a common occurrence, resulting in considerable patient suffering; it also represents a major economic burden on society. To improve treatment options following peripheral nerve injuries, scientists aim to find a way to promote Schwann cell (SC) myelination to help nerves to carry out their functions effectively. In this study, we investigated myelination ability of SCs, regulated by co-culture with adipose-derived stem cells (ASCs) or low-intensity pulsed ultrasound (LIPUS), and synergistic effects of combined treatments. MATERIALS AND METHODS Schwann cells were co-cultured with or without ASCs, and either left untreated or treated with LIPUS for 10 min/d for 1, 4 or 7 days. Effects of LIPUS and ASC co-culture on pro-myelination indicators of SCs were analysed by real-time PCR (RT-PCR), Western blotting and immunofluorescence staining (IF). RESULTS Our results indicate that ASC-SC co-culture and LIPUS, together or individually, promoted mRNA levels of epidermal growth factor receptor 3 (EGFR3/ErbB3), neuregulin1 (NRG1), early growth response protein 2 (Egr2/Krox20) and myelin basic protein (MBP), with corresponding increases in protein levels of ErbB3, NRG1 and Krox20. Interestingly, combination of ASC-SC co-culture and LIPUS displayed the most remarkable effects. CONCLUSION We demonstrated that ASCs upregulated pro-myelination indicators of SCs by indirect contact (through co-culture) and that effects could be potentiated by LIPUS. We conclude that LIPUS, as a mechanical stress, may have potential in nerve regeneration with potential clinical relevance.
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Affiliation(s)
- Yuan Yue
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Xingmei Yang
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
- Oral Implant Center, West China School of Stomatology, Sichuan University, Chengdu, China.
| | - Liang Zhang
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
- Oral Implant Center, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Xun Xiao
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Neel R Nabar
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Yunfeng Lin
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Liang Hao
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Dongjiao Zhang
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Jingyi Huo
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Jingle Li
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Xiaoxiao Cai
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
- Oral Implant Center, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Min Wang
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
- Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China.
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Zhu X, Li K, Guo X, Wang J, Xiang Y. Schwann cell proliferation and differentiation that is induced by ferulic acid through MEK1/ERK1/2 signalling promotes peripheral nerve remyelination following crush injury in rats. Exp Ther Med 2016; 12:1915-1921. [PMID: 27588110 DOI: 10.3892/etm.2016.3525] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 05/10/2016] [Indexed: 11/06/2022] Open
Abstract
Schwann cell proliferation and differentiation is critical for the remyelination of injured peripheral nerves. Ferulic acid (FA) is a widely used antioxidant agent with neuroprotective properties. However, the potentially beneficial effects of FA on Schwann cells are unknown. Therefore, the present study was designed to examine the effects of FA on Schwann cell proliferation and differentiation. By using the cultured primary Schwann cells and proliferation assay, the results identified that FA was capable of increasing Schwann cell proliferation and expression of myelin-associated glycoprotein (MAG) and myelin basic protein (MBP) in vitro. It was also observed that the beneficial effect of FA treatment on Schwann cells was mainly dependent on the activation of MEK1/ERK1/2 signalling. Furthermore, FA was intraperitoneally administered to rats with sciatic nerve crush injury, and the results revealed an increase in Schwann cell proliferation and differentiation, while the MAG and MBP expression levels in sciatic nerves were markedly upregulated following FA administration. In conclusion, the current results demonstrate that Schwann cell proliferation and differentiation is induced by FA through MEK1/ERK1/2 signalling and that FA may accelerate injured peripheral nerve remyelination.
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Affiliation(s)
- Xiaoyan Zhu
- Center of Laboratory Medicine, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Kun Li
- Center of Laboratory Medicine, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Xin Guo
- Center of Laboratory Medicine, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Jian Wang
- Department of Neurology, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Yang Xiang
- Department of Neurology, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
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Rachana KS, Manu MS, Advirao GM. Insulin influenced expression of myelin proteins in diabetic peripheral neuropathy. Neurosci Lett 2016; 629:110-115. [PMID: 27373589 DOI: 10.1016/j.neulet.2016.06.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 06/28/2016] [Accepted: 06/29/2016] [Indexed: 01/11/2023]
Abstract
Diabetic peripheral neuropathy (DPN) is one of the downstream complications of diabetes. This complication is caused by the deficiency of insulin action and subsequent hyperglycemia, but the details of their pathogenesis remain unclear. Hence, it is of critical importance to understand how such hormonal variation affects the expression of myelin proteins such as myelin basic protein (MBP) and myelin associated glycoprotein (MAG) in the peripheral nerve. An earlier report from our lab has demonstrated the expression of insulin receptors (IR) in Schwann cells (SCs) of sciatic nerve. To assess the neurotrophic role of insulin in diabetic neuropathy, we studied the expression of these myelin proteins under control, DPN and insulin treated DPN subjects at developmental stages. Further, the expression of these myelin proteins was correlated with the expression of insulin receptor. Expression of myelin proteins was significantly reduced in the diabetic model compared to normal, and upregulated in insulin treated diabetic rats. Similarly, an in vitro study was also carried out in SCs grown at high glucose and insulin treated conditions. The expression pattern of myelin proteins in SCs was comparable to that of in vivo samples. In addition, quantitative study of myelin genes by real time PCR has also showed the significant expression pattern change in the insulin treated and non-treated DPN subjects. Taken together, these results corroborate the critical importance of insulin as a neurotrophic factor in demyelinized neurons in diabetic neuropathy.
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Affiliation(s)
| | - Mallahalli S Manu
- Department of Biochemistry, Davangere University, Davangere, Karnataka, India
| | - Gopal M Advirao
- Department of Biochemistry, Davangere University, Davangere, Karnataka, India.
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Ning L, Guillemot A, Zhao J, Kipouros G, Chen X. Influence of Flow Behavior of Alginate-Cell Suspensions on Cell Viability and Proliferation. Tissue Eng Part C Methods 2016; 22:652-62. [PMID: 27166436 DOI: 10.1089/ten.tec.2016.0011] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Tissue scaffolds with living cells fabricated by three-dimensional bioprinting/plotting techniques are becoming more prevalent in tissue repair and regeneration. In the bioprinting process, cells are subject to process-induced forces (such as shear force) that can result in cell damage and loss of cell function. The flow behavior of the biomaterial solutions that encapsulate living cells in this process plays an important role. This study used a rheometer to examine the flow behavior of alginate solution and alginate-Schwann cell (RSC96), alginate-fibroblast cell (NIH-3T3), and alginate-skeletal muscle cell (L8) suspensions during shearing with respect to effects on cell viability and proliferation. The flow behavior of all the alginate-cell suspensions varied with alginate concentration and cell density and had a significant influence on the viability and proliferation of the cells once sheared as well as on the recovery of the sheared cells. These findings provide a mean to preserve cell viability and/or retain cell proliferation function in the bioprinting process by regulating the flow behavior of cell-biomaterial suspensions and process parameters.
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Affiliation(s)
- Liqun Ning
- 1 Department of Mechanical Engineering, College of Engineering, University of Saskatchewan , Saskatoon, Canada
| | - Arthur Guillemot
- 2 Department of Mechanical Engineering, Icam Engineering School , Paris, France
| | - Jingxuan Zhao
- 1 Department of Mechanical Engineering, College of Engineering, University of Saskatchewan , Saskatoon, Canada
| | - Georges Kipouros
- 3 Department of Chemical and Biological Engineering, College of Engineering, University of Saskatchewan , Saskatoon, Canada
| | - Xiongbiao Chen
- 1 Department of Mechanical Engineering, College of Engineering, University of Saskatchewan , Saskatoon, Canada .,4 Division of Biomedical Engineering, College of Engineering, University of Saskatchewan , Saskatoon, Canada
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Sub-Chronic Neuropathological and Biochemical Changes in Mouse Visual System after Repetitive Mild Traumatic Brain Injury. PLoS One 2016; 11:e0153608. [PMID: 27088355 PMCID: PMC4835061 DOI: 10.1371/journal.pone.0153608] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 03/31/2016] [Indexed: 11/29/2022] Open
Abstract
Repetitive mild traumatic brain injury (r-mTBI) results in neuropathological and biochemical consequences in the human visual system. Using a recently developed mouse model of r-mTBI, with control mice receiving repetitive anesthesia alone (r-sham) we assessed the effects on the retina and optic nerve using histology, immunohistochemistry, proteomic and lipidomic analyses at 3 weeks post injury. Retina tissue was used to determine retinal ganglion cell (RGC) number, while optic nerve tissue was examined for cellularity, myelin content, protein and lipid changes. Increased cellularity and areas of demyelination were clearly detectable in optic nerves in r-mTBI, but not in r-sham. These changes were accompanied by a ~25% decrease in the total number of Brn3a-positive RGCs. Proteomic analysis of the optic nerves demonstrated various changes consistent with a negative effect of r-mTBI on major cellular processes like depolymerization of microtubules, disassembly of filaments and loss of neurons, manifested by decrease of several proteins, including neurofilaments (NEFH, NEFM, NEFL), tubulin (TUBB2A, TUBA4A), microtubule-associated proteins (MAP1A, MAP1B), collagen (COL6A1, COL6A3) and increased expression of other proteins, including heat shock proteins (HSP90B1, HSPB1), APOE and cathepsin D. Lipidomic analysis showed quantitative changes in a number of phospholipid species, including a significant increase in the total amount of lysophosphatidylcholine (LPC), including the molecular species 16:0, a known demyelinating agent. The overall amount of some ether phospholipids, like ether LPC, ether phosphatidylcholine and ether lysophosphatidylethanolamine were also increased, while the majority of individual molecular species of ester phospholipids, like phosphatidylcholine and phosphatidylethanolamine, were decreased. Results from the biochemical analysis correlate well with changes detected by histological and immunohistochemical methods and indicate the involvement of several important molecular pathways. This will allow future identification of therapeutic targets for improving the visual consequences of r-mTBI.
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Zhang L, Yang X, Yue Y, Ye J, Yao Y, Fu Y, Li G, Yao Q, Lin Y, Gong P. Cyclic mechanical stress modulates neurotrophic and myelinating gene expression of Schwann cells. Cell Prolif 2014; 48:59-66. [PMID: 25418681 DOI: 10.1111/cpr.12151] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 09/12/2014] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES This study aimed to investigate the response of Schwann cells to cyclic compressive and tensile stresses of different durations of stimulation. MATERIALS AND METHODS RSC96 cells were subjected to cyclic tensile stress or compressive stress; for either, cells in five groups were treated for 0, 1, 2, 24 and 48 h respectively. Enzyme-linked immunosorbent assay was conducted to detect secretion of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 and neurotrophin-4 in the culture medium. Real-time PCR was conducted to quantify mRNA expression of neurotrophins including NGF, BDNF, neurotrophin-3 and neurotrophin-4, and myelin-related genes including Sox10, Krox20, neuregulin 1, NCAM, N-cadherin, P0, MAG and MBP. Immunofluorescent staining was performed to visualize Krox20 and F-actin in the tensile groups. RESULTS Within 24 h, cells treated with cyclic tensile stress expressed and secreted significantly more BDNF, while cyclic compression down-regulated BDNF expression. Cells treated with both tensile and compressive stress down-regulated expression of NRG1, NCAM, Krox20 and Sox10 at all time points. Expression of N-cadherin was not affected by either stretch or compression. F-actin was down-regulated by tensile stress. CONCLUSIONS Both tensile and compressive loading down-regulated expression of several important myelin-related Schwann cells genes and thus facilitated demyelination. Tensile stress meanwhile promoted secretion of BDNF by Schwann cells within 24 h, which may contribute to maintenance and repair of damaged axons. These effects of mechanical stress might have been mediated by the actin cytoskeleton.
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Affiliation(s)
- L Zhang
- State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, 610041, China
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Gupta R, Mozaffar T. Reply. Muscle Nerve 2012. [DOI: 10.1002/mus.23457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Changes of myelinated nerve and myelin basic protein expression in rats' periodontal ligaments after experimental tooth movement. Am J Orthod Dentofacial Orthop 2012. [PMID: 23195367 DOI: 10.1016/j.ajodo.2012.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Information about the effect of tooth movement on the myelinated nerve in the periodontal ligament is limited. In this study, we aimed to investigate what responses of the periodontal myelinated nerve can be evoked during experimental tooth movement. METHODS In experimental-I group, the maxillary left and mandibular right third molars were moved distally. In experimental-II group, the maxillary left third molar but not the right one was moved, and the bilateral mandibular third molars were extracted. The ultrastructures of the myelinated nerve in the periodontal ligament of the bilateral maxillary third molars were observed under a transmission electron microscope. The expression of myelin basic protein was evaluated by immunohistochemistry. RESULTS Degenerative ultrastructural changes of the myelinated nerve in the periodontal ligament were noticed mainly in the myelin sheath; these were observed earlier and were recoverable in the experimental-I group. In contrast, the ultrastructural changes of the myelinated nerve occurred mainly in the axons, were observed later, and were unrecoverable in the experimental-II group. A concomitant decrease of myelin basic protein expression was observed in both groups. CONCLUSIONS Both experimental tooth movement and occlusal changes accompanying it caused changes of the myelinated nerve in the periodontal ligament.
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Lin MY, Frieboes LS, Forootan M, Palispis WA, Mozaffar T, Jafari M, Steward O, Gall CM, Gupta R. Biophysical stimulation induces demyelination via an integrin-dependent mechanism. Ann Neurol 2012; 72:112-23. [PMID: 22829273 DOI: 10.1002/ana.23592] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Chronic nerve compression (CNC) injuries occur when peripheral nerves are subjected to sustained mechanical forces, with increasing evidence implicating Schwann cells as key mediators. Integrins, a family of transmembrane adhesion molecules that are capable of intracellular signaling, have been implicated in a variety of biological processes such as myelination and nerve regeneration. In this study, we seek to define the physical stimuli mediating demyelination and to determine whether integrin plays a role in the demyelinating response. METHODS We used a previously described in vitro model of CNC injury where myelinating neuron-Schwann cell cocultures were subjected to independent manipulations of hydrostatic pressure, hypoxia, and glucose deprivation in a custom bioreactor. We assessed whether demyelination increased in response to applied manipulation and determined whether integrin-associated signaling cascades are upregulated. RESULTS Biophysical stimulation of neural tissue induced demyelination and Schwann cell proliferation without neuronal or glial cytotoxicity or apoptosis. Although glucose deprivation and hypoxia independently had minor effects on myelin stability, together they potentiated the demyelinating effects of hydrostatic compression, and in combination, significantly destabilized myelin. Biophysical stimuli transiently increased phosphorylation of the integrin-associated tyrosine kinase Src within Schwann cells. Silencing this integrin signaling cascade blocked Src activation and prevented pressure-induced demyelination. Colocalization analysis indicated that Src is localized within Schwann cells. INTERPRETATION These results indicate that myelin is sensitive to CNC injury and support the novel concept that myelinating cocultures respond directly to mechanical loading via activating an integrin signaling cascade.
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Affiliation(s)
- Michael Y Lin
- Department of Orthopedic Surgery, University of California, Irvine, USA
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Gladman SJ, Ward RE, Michael-Titus AT, Knight MM, Priestley JV. The effect of mechanical strain or hypoxia on cell death in subpopulations of rat dorsal root ganglion neurons in vitro. Neuroscience 2010; 171:577-87. [PMID: 20674687 DOI: 10.1016/j.neuroscience.2010.07.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 07/01/2010] [Accepted: 07/04/2010] [Indexed: 12/22/2022]
Abstract
Spinal nerves and their associated dorsal root ganglion (DRG) cells can be subject to mechanical deformation and hypoxia associated with pathology such as disc herniation, spinal stenosis and spine trauma. There is very limited information on the response of adult DRG neurons to such stressors. In this study we used an in vitro approach to examine the response of adult DRG cells to (a) mechanical, hypoxic, and combined injuries; and (b) to compare the effects on injury on nociceptive and non-nociceptive neurons, as well as on non-neuronal cells. Mechanical injury (20% tensile strain) led to significant neuronal cell death (assessed by ethidium homodimer-1 labelling), which was proportional to strain duration (5 min, 1 h, 6 h or 18 h). Hypoxia (2% O(2) for 24 h) also promoted death of DRG neurons, and was further enhanced when mechanical strain and hypoxia were combined. Both mechanical strain and hypoxia significantly decreased the maximum neurite length. Conversely, death of non-neuronal cells was only increased by hypoxia and not by mechanical strain. Total cell death in response to mechanical injury or hypoxia was similar in both non-nociceptive (neurofilament, NF-200 immunoreactive) and nociceptive (calcitonin gene-related peptide, CGRP immunoreactive) neurons, but apoptosis (assessed by activated caspase-3 immunostaining) was significantly higher in CGRP than NF-200 neurons. Surprisingly, cell death of non-peptidergic nociceptors (identified by Griffonia simplicifolia IB4 lectin binding) was already high in control cultures, and was not increased further by either mechanical stretch or hypoxia. These results provide detailed information on the response of adult DRG subpopulations to hypoxia and mechanical strain, and describe in vitro models that could be useful for screening potential neuroprotective agents.
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Affiliation(s)
- S J Gladman
- Centre for Neuroscience and Trauma, Blizard Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT, UK.
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37
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Tapadia M, Mozaffar T, Gupta R. Compressive neuropathies of the upper extremity: update on pathophysiology, classification, and electrodiagnostic findings. J Hand Surg Am 2010; 35:668-77. [PMID: 20223605 PMCID: PMC4715364 DOI: 10.1016/j.jhsa.2010.01.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Accepted: 01/12/2010] [Indexed: 02/02/2023]
Abstract
Clinical examination and electrodiagnostic studies remain the gold standard for diagnosis of nerve injuries. Diagnosis of chronic nerve compression (CNC) injuries can be difficult in patients with confounding factors such as diabetes. The treatment of nerve entrapment ranges from medical to surgical management, depending on the nerve involved and on the severity and duration of compression. Considerable insights have been made at the molecular level, differentiating between nerve crush injuries and CNC injuries. Although the myelin changes after CNC injury were previously thought to be a mild form of Wallerian degeneration, recent evidence points to a distinct pathophysiology involving Schwann cell mechanosensitivity. Future areas of research include Schwann cell transplantation in the treatment regimen, the correlation between demyelination and the onset of pain, and the role of Schwann cell integrins in transducing the mechanical forces involved in nerve compression injuries to Schwann cells.
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Affiliation(s)
- Minal Tapadia
- Peripheral Nerve Research Laboratory, University of California, Irvine; Irvine, CA
| | - Tahseen Mozaffar
- Department of Neurology, University of California, Irvine; Irvine, CA
- Peripheral Nerve Research Laboratory, University of California, Irvine; Irvine, CA
| | - Ranjan Gupta
- Department of Orthopaedic Surgery, University of California, Irvine; Irvine, CA
- Department of Anatomy and Neurobiology, University of California, Irvine; Irvine, CA
- Department of Biomedical Engineering, University of California, Irvine; Irvine, CA
- Peripheral Nerve Research Laboratory, University of California, Irvine; Irvine, CA
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38
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Abstract
Historically, clinical outcomes following spinal cord injury have been dismal. Over the past 20 years, the survival rate and long-term outcome of patients with spinal cord injury have improved with advances in both medical and surgical treatment. However, the efficacy and timing of these adjuvant treatments remain controversial. There has been a tremendous increase in the number of basic science and clinical studies on spinal cord injury. Current areas of investigation include early acute management, including early surgical intervention, as well as new pharmacotherapy and cellular transplantation strategies. It is unlikely that a single approach can uniformly address all of the issues associated with spinal cord injury. Thus, a multidisciplinary approach will be needed.
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39
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Lin G, Mela A, Guilfoyle EM, Goldman JE. Neonatal and adult O4(+) oligodendrocyte lineage cells display different growth factor responses and different gene expression patterns. J Neurosci Res 2010; 87:3390-402. [PMID: 19360905 DOI: 10.1002/jnr.22065] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Oligodendrocytes are the myelinating cells of the central nervous system. Although the CNS possesses the ability to repair demyelinating insults, in certain cases, such as the chronic lesions found in multiple sclerosis, remyelination fails. Cycling cells capable of becoming oligodendrocytes have been identified in both the developing and the adult mammalian forebrain. Many studies have focused on differences in gene expression profiles as oligodendrocyte progenitors differentiate into myelinating oligodendrocytes by isolating cells at different developmental stages from animals at a single age. However, few have studied the differences that exist between the progenitors of the neonatal CNS and those of the adult CNS. This study examined the response of neonatal and adult O4(+) cells to platelet-derived growth factor-AA, basic fibroblast growth factor, and insulin-like growth factor-1 and revealed marked differences. Whereas adult cells readily differentiated in vitro, the majority of neonatal progenitors remained immature. Microarray analysis was used to examine differences between acutely isolated neonatal and adult progenitors further. Gene expression profiles showed that the adult O4(+) cells are more developmentally mature than neonatal cells. Neonatal cells expressed higher levels of genes involved in proliferation. Adult O4(+) cells expressed higher levels of transcripts for genes involved in cell death and survival. Therefore, O4(+) cells from the adult differ greatly from those of the neonate, and the developmental stage of the animal models utilized must be taken into consideration when applying principles from neonatal systems to the adult.
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Affiliation(s)
- Grace Lin
- Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
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40
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Pham K, Nassiri N, Gupta R. c-Jun, krox-20, and integrin beta4 expression following chronic nerve compression injury. Neurosci Lett 2009; 465:194-8. [PMID: 19765400 DOI: 10.1016/j.neulet.2009.09.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 09/04/2009] [Accepted: 09/04/2009] [Indexed: 01/27/2023]
Abstract
Limited work has been done to investigate the molecular mechanisms behind the process of demyelination and remyelination that occurs in response to chronic nerve compression (CNC) injury. In the present study, we investigated the expression of the transcription factors krox-20 and c-jun, positive and negative regulators of myelination, respectively. A decrease in krox-20 expression and an increase in c-jun expression in both its phosphorylated and non-phosphorylated states were observed. In addition, we investigated the role of integrins, specifically the beta4 subunit of the alpha6beta4 dimer, as a possible upstream signal transducer in the signaling cascade leading to demyelination. We detected a decrease in beta4 integrin expression at 2 and 4 weeks post-injury and a concomitant relocalization to the Schmidt-Lanterman Incisures, suggesting a role for the beta4 integrin in facilitating Schwann cell-extracellular matrix interaction. The observed changes in transcription factor and integrin expression are temporally correlated with the process of demyelination, and suggest further investigation to define their definitive role in regulating the myelin response to CNC injury.
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Affiliation(s)
- Khoa Pham
- Department of Orthopaedic Surgery, University of California, Irvine, Irvine, CA, United States
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41
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Pham K, Gupta R. Understanding the mechanisms of entrapment neuropathies. Review article. Neurosurg Focus 2009; 26:E7. [PMID: 19435447 DOI: 10.3171/foc.2009.26.2.e7] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Compression neuropathies are highly prevalent, debilitating conditions with variable functional recovery following surgical decompression. Due to the limited amount of human nerve tissue available for analysis, a number of animal models have been created to help investigators understand the molecular and cellular pathogenesis of chronic nerve compression (CNC) injury. Evidence suggests that CNC injury induces concurrent Schwann cell proliferation and apoptosis in the early stages of the disorder. These proliferating Schwann cells downregulate myelin proteins, leading to local demyelination and remyelination in the region of injury. In addition, the downregulation of myelin proteins, in particular myelin-associated glycoprotein, allows for axonal sprouting. Interestingly, these changes occur in the absence of both morphological and electrophysiological evidence of axonal damage. This is in direct contrast to acute injuries, such as transection or crush, which are characterized by axonal injury followed by Wallerian degeneration. Because the accepted trigger for Schwann cell dedifferentiation is axonal injury, an alternate mechanism for Schwann response must exist in CNC injury. In vitro studies of pure Schwann cells have shown that these cells can respond directly to mechanical stimuli by downregulating myelin proteins and proliferating. These studies suggest that although the reciprocal relationship between neurons and glial cells is maintained, chronic nerve compression injury is a Schwann cell-mediated disease.
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Affiliation(s)
- Khoa Pham
- Department of Orthopaedic Surgery, University of California, Irvine, California, USA
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42
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Mozaffar T, Strandberg E, Abe K, Hilgenberg LG, Smith MA, Gupta R. Neuromuscular junction integrity after chronic nerve compression injury. J Orthop Res 2009; 27:114-9. [PMID: 18655131 PMCID: PMC2670070 DOI: 10.1002/jor.20704] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Chronic nerve compression injuries (CNC) are progressive demyelinating disorders characterized by a gradual decline of the nerve conduction velocity (NCV) in the affected nerve region. CNC injury induces a robust Schwann cell response with axonal sprouting, but without morphologic evidence of axonal injury. We hypothesize that early CNC injury occurs without damage to neuromuscular junction of motor axons. A well-established animal model was used to assess for damage to motor axons. As sprouting is considered a hallmark of regeneration during and after axonal degeneration and sprouting was confirmed visually at 2 weeks in CNC animals, we assessed for axonal degeneration in motor nerves after CNC by evaluating the integrity of the neuromuscular junction. NCV exhibited a gradual progressive decline consistent with the human condition. Compound motor action potential amplitudes decreased slightly immediately and plateaued, indicating that there was not sustained and increasing axonal loss. Sprouting was confirmed using immunofluorescence and by an increase in number of unmyelinated axons and Remak bundles. Blind analysis of the neuromuscular junction showed no difference between control and CNC images, indicating that there was no evidence for end-unit axonal loss in the soleus muscle. Because the progressive decline in NCV was not paired with a similar progressive decline in amplitude, it is likely that axonal loss is not responsible for slowing of action potentials. Blind analysis of the neuromuscular junction provides further evidence that the axonal sprouting seen early after CNC injury is not a consequence of axonal degeneration in the motor nerves.
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Affiliation(s)
- Tahseen Mozaffar
- Department of Neurology, 101 The City Drive South, Bldg. 22 C, Route 13, Orange, California 92868,Peripheral Nerve Research Laboratory, 2226 Gillespie Neuroscience Research Facility, University of California, Irvine, Calfornia 92697-4292
| | - Erika Strandberg
- Department of Orthopaedics, 101 The City Drive South, Pavilion III, Orange, California 92868,Peripheral Nerve Research Laboratory, 2226 Gillespie Neuroscience Research Facility, University of California, Irvine, Calfornia 92697-4292
| | - Kazuko Abe
- Department of Orthopaedics, 101 The City Drive South, Pavilion III, Orange, California 92868,Peripheral Nerve Research Laboratory, 2226 Gillespie Neuroscience Research Facility, University of California, Irvine, Calfornia 92697-4292
| | - Lutz G. Hilgenberg
- Department of Anatomy and Neurobiology, 110 Irvine Hall, University of California, Irvine, CA 92697-1280
| | - Martin A. Smith
- Department of Anatomy and Neurobiology, 110 Irvine Hall, University of California, Irvine, CA 92697-1280
| | - Ranjan Gupta
- Department of Orthopaedics, 101 The City Drive South, Pavilion III, Orange, California 92868,Department of Anatomy and Neurobiology, 110 Irvine Hall, University of California, Irvine, CA 92697-1280,Peripheral Nerve Research Laboratory, 2226 Gillespie Neuroscience Research Facility, University of California, Irvine, Calfornia 92697-4292
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Chao T, Pham K, Steward O, Gupta R. Chronic nerve compression injury induces a phenotypic switch of neurons within the dorsal root ganglia. J Comp Neurol 2008; 506:180-93. [PMID: 18022951 DOI: 10.1002/cne.21537] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chronic nerve compression (CNC) injury initiates a series of pathological changes within the peripheral nerve at the site of injury. However, to date, little work has been performed to explore neuronal cell body responses to CNC injury. Here we show a preferential upregulation of growth-associated protein-43 (GAP-43) and enhanced Fluoro Ruby uptake by the small-diameter calcitonin gene-related protein (CGRP) and isolectin B4 (IB4)-positive neurons in the L4 and L5 ipsilateral dorsal root ganglion (DRG) 2 weeks and 1 month post injury. Furthermore, L4 and L5 DRGs ipsilateral to CNC injury also demonstrated a marked reduction in neurofilament 200 (NF-200) neurons and an increase in CGRP and IB4 neurons at early time points. All numbers normalized to values comparable to those of control when the DRG was evaluated 6 months post injury. Quantification of glial-derived neurotrophic factor (GDNF) protein revealed an upregulation in L4 and L5 DRG followed by a return to baseline values at later stages following injury. Upregulation of GDNF expression by Schwann cells was also readily apparent with both immunohistochemistry and Western blot analysis of 1 month compressed sciatic nerve specimens. Thus, CNC induces a phenotypic change in the DRG that appears to be temporally associated with increases in GDNF protein expression at and near the site of the compression injury in the nerve.
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Affiliation(s)
- Tom Chao
- Department of Orthopaedic Surgery, University of California, Irvine, Irvine, California 92697, USA
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44
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The effect of the alignment of electrospun fibrous scaffolds on Schwann cell maturation. Biomaterials 2007; 29:653-61. [PMID: 17983651 DOI: 10.1016/j.biomaterials.2007.10.025] [Citation(s) in RCA: 343] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 10/17/2007] [Indexed: 12/26/2022]
Abstract
Peripheral nerve regeneration can be enhanced by the stimulation of formation of bands of Büngner prior to implantation. Aligned electrospun poly(epsilon-caprolactone) (PCL) fibers were fabricated to test their potential to provide contact guidance to human Schwann cells. After 7 days of culture, cell cytoskeleton and nuclei were observed to align and elongate along the fiber axes, emulating the structure of bands of Büngner. Microarray analysis revealed a general down-regulation in expression of neurotrophin and neurotrophic receptors in aligned cells as compared to cells seeded on two-dimensional PCL film. Real-time-PCR analyses confirmed the up-regulation of early myelination marker, myelin-associated glycoprotein (MAG), and the down-regulation of NCAM-1, a marker of immature Schwann cells. Similar gene expression changes were also observed on cells cultured on randomly oriented PCL electrospun fibers. However, up-regulation of the myelin-specific gene, P0, was observed only on aligned electrospun fibers, suggesting the propensity of aligned fibers in promoting Schwann cell maturation.
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45
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Gray M, Palispis W, Popovich PG, van Rooijen N, Gupta R. Macrophage depletion alters the blood-nerve barrier without affecting Schwann cell function after neural injury. J Neurosci Res 2007; 85:766-77. [PMID: 17266098 DOI: 10.1002/jnr.21166] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previous work has shown that, during the early phases of chronic nerve compression (CNC) injury, axonal pathology is absent while Schwann cells undergo a dramatic process of cellular turnover with marked proliferation. It is known that macrophages may release Schwann cell mitogens, so we sought to explore the role of macrophages in CNC injury by selectively depleting the population of hematogenously derived macrophages in nerves undergoing CNC injury by injecting clodronate liposomes at days 1, 3, and 6 postinjury and evaluating both the integrity of the blood-nerve barrier (BNB) and Schwann cell function. Integrity of the BNB was evaluated by intravenously injecting Evans blue albumin (EBA), and Schwann cell number was determined via stereologic techniques. The BNB was clearly altered by 2 weeks postinjury and continued to disintegrate at later time points. Macrophage depletion attenuated this response at all observed time points. Quantification of Schwann cell nuclei in CNC nerves showed no differences between compressed sections of macrophage-depleted and nondepleted animals. Although macrophages are largely responsible for the increased vascular permeability associated with CNC injury, it is likely that the Schwann cell response to CNC injury is not influenced by macrophage-derived mitogenic signals but rather must be mediated via alternative mechanisms.
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Affiliation(s)
- Michael Gray
- Department of Orthopaedic Surgery, University of California, Irvine, Irvine, California, USA
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46
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Berger BL, Gupta R. Demyelination secondary to chronic nerve compression injury alters Schmidt-Lanterman incisures. J Anat 2007; 209:111-8. [PMID: 16822274 PMCID: PMC2100307 DOI: 10.1111/j.1469-7580.2006.00561.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The role of Schmidt-Lanterman incisures (SLIs) within the myelin sheath remains the subject of much debate. Previous studies have shown a positive correlation between the number of SLIs per internode and internodal width for both normal and pathological myelin internodes. As chronic nerve compression (CNC) injury induces demyelination, we sought to evaluate if CNC injury altered the occurrence of SLIs using nerve-teasing techniques and light microscopy. Rigorous examination of the teased axons from nerves subjected to CNC injury for 1 month, 2 months or 8 months revealed that there is indeed a positive correlation between the number of SLIs per internode and the internodal width. However, unlike previous studies, the degree of positive correlation between these two parameters was greater in the internodes that had undergone remyelination in response to CNC injury as compared with the internodes from control nerves. These findings support the theory that SLIs are likely to assist in the metabolic processes of the myelin sheath, including growth and maintenance of the myelin sheath.
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Affiliation(s)
- Brent L Berger
- Department of Orthopedic Surgery, University of California, Irvine, CA 92697-4292, USA
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47
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Rasouli A, Bhatia N, Suryadevara S, Cahill K, Gupta R. Transplantation of preconditioned schwann cells in peripheral nerve grafts after contusion in the adult spinal cord. Improvement of recovery in a rat model. J Bone Joint Surg Am 2006; 88:2400-10. [PMID: 17079397 DOI: 10.2106/jbjs.e.01424] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Recovery after injury to the peripheral nervous system is based on the pro-regenerative relationship between axons and the extracellular matrix, a relationship established by Schwann cells. As mechanical conditioning of Schwann cells has been shown to stimulate their regenerative behavior, we sought to determine whether transplantation of these cells to the central nervous system (i.e., the spinal cord), with its limited regenerative capacity after injury, would improve axonal regeneration and functional recovery. METHODS A moderate contusion injury of the spinal cord was created with a force-directed impactor in forty-eight adult Sprague-Dawley rats, and, at one week postinjury, the spinal cords were reexposed in all animals. In twenty-four of these animals, peripheral nerve grafts with Schwann cells that had been obtained from the sciatic nerves of donor animals, and had been either untreated or subjected to mechanical conditioning, were transplanted to the contused area of the cords following resection of the glial scar. Another group of animals was treated with glial scar excision only, and a fourth group had the contusion injury but neither glial excision nor transplantation. Scores according to the Basso, Beattie, Bresnahan (BBB) Locomotor Rating Scale were assigned preoperatively and weekly thereafter. Tract tracing of descending and ascending spinal cord tracts was performed at six weeks postoperatively for quantitative histological evaluation of axonal regeneration. RESULTS While the recovery following glial scar excision without peripheral nerve transplantation was significantly worse than the recovery in the other groups, both transplantation groups had significantly higher BBB scores than the controls (no transplantation) in the early postoperative period (p < 0.05). Moreover, histological analysis showed markedly increased axonal regeneration at the lesional sites in the animals treated with the mechanically conditioned grafts than in the other groups (p < 0.05). CONCLUSIONS Functional recovery after spinal cord contusion improved following glial scar excision with transplantation of Schwann cells in peripheral nerve grafts to the contusion areas. Although recovery did not differ significantly between the transplantation groups, only the preconditioned grafts led to axonal regeneration at and past the lesional site. These grafts may further enhance functional recovery as the descending tracts eventually reach their target end-organs.
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Affiliation(s)
- Alexandre Rasouli
- University of California, Irvine, 2226 Gillespie Neuroscience Research Facility, Irvine, CA 92697, USA
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48
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Gupta R, Rummler LS, Palispis W, Truong L, Chao T, Rowshan K, Mozaffar T, Steward O. Local down-regulation of myelin-associated glycoprotein permits axonal sprouting with chronic nerve compression injury. Exp Neurol 2006; 200:418-29. [PMID: 16764860 DOI: 10.1016/j.expneurol.2006.02.134] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Revised: 02/23/2006] [Accepted: 02/28/2006] [Indexed: 11/19/2022]
Abstract
Chronic nerve compression (CNC) injuries induce a robust Schwann cell proliferation in a distinct spatial and temporal pattern, which is accompanied by an increase in the number of small un-myelinated axons in the area of the injury. These findings suggest that this local proliferation of Schwann cells may induce local axonal sprouting. Here, we use quantitative electron microscopic techniques to define the nature of this sprouting response, and explore whether the local sprouting is in response to down-regulation of expression of myelin-associated glycoprotein (MAG) by proliferating Schwann cells. Axonal sprouting was observed without evidence of Wallerian degeneration in the outer region of CNC-injured nerves with a noticeable increase in Remak bundles within this region of injury. Immunolabeling of teased nerve fibers and Western blot analysis of nerves from CNC-injured animals revealed a local down-regulation of MAG protein within the zone of injury. Moreover, local delivery of purified MAG protein intraneurally at the time of CNC model creation abrogates the axonal sprouting response. These data demonstrate that CNC injury triggers axonal sprouting and suggests that a local down-regulation of MAG within the peripheral nerve secondary to CNC injury is the critical signal for the sprouting response.
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Affiliation(s)
- Ranjan Gupta
- Department of Orthopaedic Surgery, University of California, Irvine, 92657, USA.
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