Transplantation of Schwann cells in a collagen tube for the repair of large, segmental peripheral nerve defects in rats

Object Segmental nerve defects pose a daunting clinical challenge, as peripheral nerve injury studies have established that there is a critical nerve gap length for which the distance cannot be successfully bridged with current techniques. Construction of a neural prosthesis filled with Schwann cells (SCs) could provide an alternative treatment to successfully repair these long segmental gaps in the peripheral nervous system. The object of this study was to evaluate the ability of autologous SCs to increase the length at which segmental nerve defects can be bridged using a collagen tube. Methods The authors studied the use of absorbable collagen conduits in combination with autologous SCs (200,000 cells/μl) to promote axonal growth across a critical size defect (13 mm) in the sciatic nerve of male Fischer rats. Control groups were treated with serum only–filled conduits of reversed sciatic nerve autografts. Animals were assessed for survival of the transplanted SCs as well as the quantity of myelinated axons in the proximal, middle, and distal portions of the channel. Results Schwann cell survival was confirmed at 4 and 16 weeks postsurgery by the presence of prelabeled green fluorescent protein–positive SCs within the regenerated cable. The addition of SCs to the nerve guide significantly enhanced the regeneration of myelinated axons from the nerve stump into the proximal (p < 0.001) and middle points (p < 0.01) of the tube at 4 weeks. The regeneration of myelinated axons at 16 weeks was significantly enhanced throughout the entire length of the nerve guide (p < 0.001) as compared with their number in a serum–only filled tube and was similar in number compared with the reversed autograft. Autotomy scores were significantly lower in the animals whose sciatic nerve was repaired with a collagen conduit either without (p < 0.01) or with SCs (p < 0.001) when compared with a reversed autograft. Conclusions The technique of adding SCs to a guidance channel significantly enhanced the gap distance that can be repaired after peripheral nerve injury with long segmental defects and holds promise in humans. Most importantly, this study represents some of the first essential steps in bringing autologous SC-based therapies to the domain of peripheral nerve injuries with long segmental defects.

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Peripheral sensory neurons and non-neuronal cells express functional Piezo1 that is activated in peripheral nerve injury-induced neuropathic pain

10.1101/2021.10.05.463243 ◽

2021 ◽

Author(s):

Seung Min Shin ◽

Brandon Itson-Zoske ◽

Fan Fan ◽

Cheryl L. Stucky ◽

Quinn H. Hogan ◽

...

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Peripheral Nerve ◽

Schwann Cells ◽

Nerve Injury ◽

Sensory Neurons ◽

Peripheral Nerve Injury ◽

Neuronal Cells ◽

Satellite Glial Cells ◽

Peripheral Sensory

AbstractHere, we present evidence showing Piezo1 expression in the primary sensory neurons (PSNs) and non-neuronal cells of rat peripheral nervous system. Using a knockdown/knockout validated antibody, we detected Piezo1 immunoreactivity (IR) in ∼80% of PSNs of rat dorsal root ganglia (DRG) with higher IR density in the small- and medium-sized neurons, and within axons extending to both central presynaptic terminals innervating to the spinal dorsal horn and peripheral cutaneous sensory terminals in the skin. Piezo-IR was clearly identified in DRG perineuronal glia, including satellite glial cells (SGCs) and non-myelinating Schwann cells; in sciatic nerve Schwann cells surrounding the axons and cutaneous afferent endings; and in skin epidermal Merkel cells and melanocytes. Neuronal and non-neuronal Piezo1 channels were functional, since various cells (dissociated PSNs and SGCs from DRGs, isolated Schwann cells, and primary human melanocytes) exhibited a robust response to Piezo1 agonist Yoda1 by an increase of intracellular Ca2+ concentration ([Ca2+]i). These responses were abolished by Piezo1 antagonist GsMTx4. Immunoblots showed elevated Piezo1 protein in DRG proximal to peripheral nerve injury-induced painful neuropathy, while PSNs and SGCs from rats with neuropathic pain showed greater Yuda1-evoked elevation of [Ca2+]i and an increased frequency of cells responding to Yoda1, compared to controls. Ipsilateral sciatic nerve application of GsMTx4 alleviated mechanical hypersensitivity following nerve injury. Overall, our data show that Piezo1 is widely expressed by the neuronal and non-neuronal cells in the peripheral sensory pathways and that painful nerve injury is associated with activation of Piezo1 in PSNs and peripheral glia cells.

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Altered expression of neuronal cell adhesion molecules induced by nerve injury and repair.

The Journal of Cell Biology ◽

10.1083/jcb.103.3.929 ◽

1986 ◽

Vol 103 (3) ◽

pp. 929-945 ◽

Cited By ~ 208

Author(s):

J K Daniloff ◽

G Levi ◽

M Grumet ◽

F Rieger ◽

G M Edelman

Keyword(s):

Spinal Cord ◽

Cell Adhesion ◽

Sciatic Nerve ◽

Peripheral Nerve ◽

Schwann Cells ◽

Nerve Injury ◽

Adhesion Molecule ◽

Peripheral Nerve Injury ◽

Dorsal Root ◽

Cell Adhesion Molecule

Peripheral nerve injury results in short-term and long-term changes in both neurons and glia. In the present study, immunohistological and immunoblot analyses were used to examine the expression of the neural cell adhesion molecule (N-CAM) and the neuron-glia cell adhesion molecule (Ng-CAM) within different parts of a functionally linked neuromuscular system extending from skeletal muscle to the spinal cord after peripheral nerve injury. Histological samples were taken from 3 to 150 d after crushing or transecting the sciatic nerve in adult chickens and mice. In unperturbed tissues, both N-CAM and Ng-CAM were found on nonmyelinated axons, and to a lesser extent on Schwann cells and myelinated axons. Only N-CAM was found on muscles. After denervation, the following changes were observed: The amount of N-CAM in muscle fibers increased transiently on the surface and in the cytoplasm, and in interstitial spaces between fibers. Restoration of normal N-CAM levels in muscle was dependent on reinnervation; in a chronically denervated state, N-CAM levels remained high. After crushing or cutting the nerve, the amount of both CAMs increased in the area surrounding the lesion, and the predominant form of N-CAM changed from a discrete Mr 140,000 component to the polydisperse high molecular weight embryonic form. Anti-N-CAM antibodies stained neurites, Schwann cells, and the perineurium of the regenerating sciatic nerve. Anti-Ng-CAM antibodies labeled neurites, Schwann cells and the endoneurial tubes in the distal stump. Changes in CAM distribution were observed in dorsal root ganglia and in the spinal cord only after the nerve was cut. The fibers within affected dorsal root ganglia were more intensely labeled for both CAMs, and the motor neurons in the ventral horn of the spinal cord of the affected segments were stained more intensely in a ring pattern by anti-N-CAM and anti-Ng-CAM than their counterparts on the side contralateral to the lesion. Taken together with the previous studies (Rieger, F., M. Grumet, and G. M. Edelman, J. Cell Biol. 101:285-293), these data suggest that local signals between neurons and glia may regulate CAM expression in the spinal cord and nerve during regeneration, and that activity may regulate N-CAM expression in muscle. Correlations of the present observations are made here with established events of nerve degeneration and suggest a number of roles for the CAMs in regenerative events.(ABSTRACT TRUNCATED AT 400 WORDS)

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Changes in Crossed Spinal Reflexes After Peripheral Nerve Injury and Repair

Journal of Neurophysiology ◽

10.1152/jn.00305.2001 ◽

2002 ◽

Vol 87 (4) ◽

pp. 1763-1771 ◽

Cited By ~ 34

Author(s):

Antoni Valero-Cabré ◽

Xavier Navarro

Keyword(s):

Sciatic Nerve ◽

Action Potential ◽

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Tibialis Anterior ◽

Tibial Nerve ◽

Spinal Reflexes ◽

Injury And Repair

We investigated the changes induced in crossed extensor reflex responses after peripheral nerve injury and repair in the rat. Adults rats were submitted to non repaired sciatic nerve crush (CRH, n = 9), section repaired by either aligned epineurial suture (CS, n = 11) or silicone tube (SIL4, n = 13), and 8 mm resection repaired by tubulization (SIL8, n = 12). To assess reinnervation, the sciatic nerve was stimulated proximal to the injury site, and the evoked compound muscle action potential (M and H waves) from tibialis anterior and plantar muscles and nerve action potential (CNAP) from the tibial nerve and the 4th digital nerve were recorded at monthly intervals for 3 mo postoperation. Nociceptive reinnervation to the hindpaw was also assessed by plantar algesimetry. Crossed extensor reflexes were evoked by stimulation of the tibial nerve at the ankle and recorded from the contralateral tibialis anterior muscle. Reinnervation of the hindpaw increased progressively with time during the 3 mo after lesion. The degree of muscle and sensory target reinnervation was dependent on the severity of the injury and the nerve gap created. The crossed extensor reflex consisted of three bursts of activity (C1, C2, and C3) of gradually longer latency, lower amplitude, and higher threshold in control rats. During follow-up after sciatic nerve injury, all animals in the operated groups showed recovery of components C1 and C2 and of the reflex H wave, whereas component C3 was detected in a significantly lower proportion of animals in groups with tube repair. The maximal amplitude of components C1 and C2 recovered to values higher than preoperative values, reaching final levels between 150 and 245% at the end of the follow-up in groups CRH, CS, and SIL4. When reflex amplitude was normalized by the CNAP amplitude of the regenerated tibial nerve, components C1 (300–400%) and C2 (150–350%) showed highly increased responses, while C3 was similar to baseline levels. In conclusion, reflexes mediated by myelinated sensory afferents showed, after nerve injuries, a higher degree of facilitation than those mediated by unmyelinated fibers. These changes tended to decline toward baseline values with progressive reinnervation but still remained significant 3 mo after injury.

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SUR1, newly expressed in astrocytes, mediates neuropathic pain in a mouse model of peripheral nerve injury

Molecular Pain ◽

10.1177/17448069211006603 ◽

2021 ◽

Vol 17 ◽

pp. 174480692110066

Author(s):

Orest Tsymbalyuk ◽

Volodymyr Gerzanich ◽

Aaida Mumtaz ◽

Sanketh Andhavarapu ◽

Svetlana Ivanova ◽

...

Keyword(s):

Spinal Cord ◽

Neuropathic Pain ◽

Sciatic Nerve ◽

Peripheral Nerve ◽

Dorsal Horn ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Thermal Sensitivity ◽

Gradual Improvement ◽

Pain Behaviors

Background Neuropathic pain following peripheral nerve injury (PNI) is linked to neuroinflammation in the spinal cord marked by astrocyte activation and upregulation of interleukin 6 (IL -6 ), chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-X-C motif) ligand 1 (CXCL1), with inhibition of each individually being beneficial in pain models. Methods Wild type (WT) mice and mice with global or pGfap-cre- or pGFAP-cre/ERT2-driven Abcc8/SUR1 deletion or global Trpm4 deletion underwent unilateral sciatic nerve cuffing. WT mice received prophylactic (starting on post-operative day [pod]-0) or therapeutic (starting on pod-21) administration of the SUR1 antagonist, glibenclamide (10 µg IP) daily. We measured mechanical and thermal sensitivity using von Frey filaments and an automated Hargreaves method. Spinal cord tissues were evaluated for SUR1-TRPM4, IL-6, CCL2 and CXCL1. Results Sciatic nerve cuffing in WT mice resulted in pain behaviors (mechanical allodynia, thermal hyperalgesia) and newly upregulated SUR1-TRPM4 in dorsal horn astrocytes. Global and pGfap-cre-driven Abcc8 deletion and global Trpm4 deletion prevented development of pain behaviors. In mice with Abcc8 deletion regulated by pGFAP-cre/ERT2, after pain behaviors were established, delayed silencing of Abcc8 by tamoxifen resulted in gradual improvement over the next 14 days. After PNI, leakage of the blood-spinal barrier allowed entry of glibenclamide into the affected dorsal horn. Daily repeated administration of glibenclamide, both prophylactically and after allodynia was established, prevented or reduced allodynia. The salutary effects of glibenclamide on pain behaviors correlated with reduced expression of IL-6, CCL2 and CXCL1 by dorsal horn astrocytes. Conclusion SUR1-TRPM4 may represent a novel non-addicting target for neuropathic pain.

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Gene transfer to schwann cells after peripheral nerve injury: A delivery system for therapeutic agents

Annals of Neurology ◽

10.1002/ana.410430210 ◽

1998 ◽

Vol 43 (2) ◽

pp. 205-211 ◽

Cited By ~ 39

Author(s):

Jesper Sørensen ◽

Georg Haase ◽

Christian Krarup ◽

Helene Gilgenkrantz ◽

Axel Kahn ◽

...

Keyword(s):

Gene Transfer ◽

Peripheral Nerve ◽

Schwann Cells ◽

Nerve Injury ◽

Delivery System ◽

Peripheral Nerve Injury ◽

Therapeutic Agents

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The dynamic changes of main cell types in the microenvironment of sciatic nerves following sciatic nerve injury and the influence of let-7 on their distribution

RSC Advances ◽

10.1039/c8ra08298g ◽

2018 ◽

Vol 8 (72) ◽

pp. 41181-41191 ◽

Cited By ~ 4

Author(s):

Tianmei Qian ◽

Pan Wang ◽

Qianqian Chen ◽

Sheng Yi ◽

Qianyan Liu ◽

...

Keyword(s):

Sciatic Nerve ◽

Peripheral Nerve ◽

Schwann Cells ◽

Nerve Injury ◽

Cell Types ◽

Sciatic Nerve Injury ◽

Dynamic Changes ◽

Main Cell ◽

Sciatic Nerves

Schwann cells (SCs), fibroblasts and macrophages are the main cells in the peripheral nerve stumps.

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The macrophage response to central and peripheral nerve injury. A possible role for macrophages in regeneration.

Journal of Experimental Medicine ◽

10.1084/jem.165.4.1218 ◽

1987 ◽

Vol 165 (4) ◽

pp. 1218-1223 ◽

Cited By ~ 423

Author(s):

V H Perry ◽

M C Brown ◽

S Gordon

Keyword(s):

Optic Nerve ◽

Peripheral Nerve ◽

Schwann Cells ◽

Nerve Injury ◽

Peripheral Nerves ◽

Peripheral Nerve Injury ◽

Macrophage Response ◽

Large Numbers ◽

Myelin Degradation ◽

Degenerating Axons

Using mAbs and immunocytochemistry we have examined the response of macrophages (M phi) after crush injury to the sciatic or optic nerve in the mouse and rat. We have established that large numbers of M phi enter peripheral nerves containing degenerating axons; the M phi are localized to the portion containing damaged axons, and they phagocytose myelin. The period of recruitment of the M phi in the peripheral nerve is before and during the period of maximal proliferation of the Schwann cells. In contrast, the degenerating optic nerve attracts few M phi, and the removal of myelin is much slower. These results show the clearly different responses of M phi to damage in the central and peripheral nervous systems, and suggest that M phi may be an important component of subsequent repair as well as myelin degradation.

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Expression of Nrf2 Promotes Schwann Cell-Mediated Sciatic Nerve Recovery in Diabetic Peripheral Neuropathy

Cellular Physiology and Biochemistry ◽

10.1159/000489373 ◽

2018 ◽

Vol 46 (5) ◽

pp. 1879-1894 ◽

Cited By ~ 13

Author(s):

Wei Tang ◽

Xiangfang Chen ◽

Haoqi Liu ◽

Qian Lv ◽

Junjie Zou ◽

...

Keyword(s):

Peripheral Neuropathy ◽

Sciatic Nerve ◽

Peripheral Nerve ◽

Nerve Injury ◽

Rat Model ◽

Peripheral Nerve Injury ◽

Signal Pathway ◽

Inflammatory Factors ◽

Survival Ratio ◽

Nrf2 Expression

Background/Aims: High glucose-induced oxidative stress and inflammatory responses play an important role in painful diabetic neuropathy by activating the TLR4/NFκB signal pathway. Schwann cells (SCs) are integral to peripheral nerve biology, contributing to saltatory conduction along axons, nerve and axon development, and axonal regeneration. SCs provide a microenvironment favoring vascular regeneration but their low survival ratio in hyperglycemic conditions suppress the function to promote nerve growth. Nuclear factor erythroid 2-related factor 2 (Nrf2) promotes remyelination after peripheral nerve injury. The aim of this study was to identify the role of Nrf2 in SC-mediated functional recovery after sciatic nerve injury. Methods: We compared plasma inflammatory factors in diabetic patients (DN) with/without diabetic peripheral neuropathy (DPN) and assessed whether Nrf2 expression in SCs could repair peripheral nerve injury in a rat model. Nrf2, TLR4/NFκB signal pathway and apoptosis relative protein expression were detected by western blot. Apoptosis and angiogenesis were determined by immunofluorescence and tubule formation assay, respectively. Regenerated nerves were determined by transmission electron microscope. Results: Higher levels of inflammatory factors and VEGF expression were found in DPN patients. Cellular experiments indicate that Nrf2 expression inhibits hyperglycemia-induced apoptosis and promotes angiogenesis by regulating the TLR4/NFκB signal pathway. Animal experiments show that nerve conduction velocity, myelin sheath thickness, and sciatic vasa nervorum are restored with transplantation of SCs overexpressing Nrf2. Conclusions: Taken together, the high survival ratio of SCs in a DPN rat model indicates that overexpression of Nrf2 restores nerve injury.

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Functional Recovery via Preregenerated Nerve Graft in Rat Sciatic Nerve Injury Model

Neurosurgery ◽

10.1093/neuros/nyz310_145 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Umang Khandpur ◽

Ying Yan ◽

Wilson Zachary Ray ◽

Matthew R MacEwan

Keyword(s):

Sciatic Nerve ◽

Peripheral Nerve ◽

Nerve Injury ◽

Functional Recovery ◽

Peripheral Nerve Injury ◽

Muscle Force ◽

Nerve Graft ◽

Tissue Loss ◽

Limb Amputation ◽

Percent Recovery

Abstract INTRODUCTION Patients who have experienced major tissue loss with peripheral nerve injury (eg, limb amputation) may be offered composite tissue allotransplantation (CTA). The return of sensory ability and cosmetic component of CTAs make them an attractive alternative to prosthetic devices. Unfortunately, robust reinnervation especially over great distances remains an issue for hand allotransplants. In this study, we introduce a preregenerated nerve graft to shorten the distance and therefore time to terminal tissue reinnervation, which could improve the utility of CTAs. METHODS A total of 18 rats weighing 250 to 300 gm each were randomized into 1 of 3 groups: baseline, fresh, or preregenerated. The baseline group underwent sham surgery to obtain baseline functional data. The fresh and preregenerated groups both underwent grafting of the sciatic nerve but the preregenerated group utilized 8-wk preregenerated grafts. At postperative week 8 from distal neurorrhaphy, both groups underwent terminal functional testing via EMG and evoked muscle force. RESULTS The preregenerated group had significantly greater mean EMG (P < .05) and maximum tetanic muscle force values (P < .05) than the fresh group. Mean percent recovery in EMG for the fresh group was 21.95% compared with 81.79% in the preregenerated group. Mean percent recovery in muscle force was 9.46% and 33.15%, respectively. CONCLUSION The results of this study provide a novel approach to enhance final functional recovery after peripheral nerve injury. The current practice of constructing a nerve stump may be improved by grafting a nerve segment at the time of injury and allowing it to preregenerate into local musculature so that if a CTA is later performed, an expedited and more robust reinnervation could be accomplished.

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