Application of custom anatomy-based nerve conduits on rabbit sciatic nerve defects: in vitro and in vivo evaluations

Toll-like receptors (TLRs) are key receptors through which infectious and non-infectious challenges act with consequent activation of the inflammatory cascade that plays a critical function in various acute and chronic diseases, behaving as amplification and chronicization factors of the inflammatory response. Previous studies have shown that synthetic analogues of lipid A based on glucosamine with few chains of unsaturated and saturated fatty acids, bind MD-2 and inhibit TLR4 receptors. These synthetic compounds showed antagonistic activity against TLR4 activation in vitro by LPS, but little or no activity in vivo. This study aimed to show the potential use of N-palmitoyl-D-glucosamine (PGA), a bacterial molecule with structural similarity to the lipid A component of LPS, which could be useful for preventing LPS-induced tissue damage or even peripheral neuropathies. Molecular docking and molecular dynamics simulations showed that PGA stably binds MD-2 with a MD-2/(PGA)3 stoichiometry. Treatment with PGA resulted in the following effects: (i) it prevented the NF-kB activation in LPS stimulated RAW264.7 cells; (ii) it decreased LPS-induced keratitis and corneal pro-inflammatory cytokines, whilst increasing anti-inflammatory cytokines; (iii) it normalized LPS-induced miR-20a-5p and miR-106a-5p upregulation and increased miR-27a-3p levels in the inflamed corneas; (iv) it decreased allodynia in peripheral neuropathy induced by oxaliplatin or formalin, but not following spared nerve injury of the sciatic nerve (SNI); (v) it prevented the formalin- or oxaliplatin-induced myelino-axonal degeneration of sciatic nerve. SIGNIFICANCE STATEMENT We report that PGA acts as a TLR4 antagonist and this may be the basis of its potent anti-inflammatory activity. Being unique because of its potency and stability, as compared to other similar congeners, PGA can represent a tool for the optimization of new TLR4 modulating drugs directed against the cytokine storm and the chronization of inflammation.

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Continuation of fast axonal transport in regenerating axons in vitro

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y79-189 ◽

1979 ◽

Vol 57 (11) ◽

pp. 1251-1255

Author(s):

M. A. Bisby ◽

C. E. Hilton

Keyword(s):

Sciatic Nerve ◽

Vagus Nerve ◽

Axonal Transport ◽

Nerve Injury ◽

Axon Regeneration ◽

Free Medium ◽

Fast Axonal Transport ◽

Sensory Axons

A previous study by McLean and co-workers reported that regenerating axons of the rabbit vagus nerve were unable to sustain axonal transport in vitro for several months after nerve injury. In contrast, we found that sensory axons of the rat sciatic nerve were able to transport 3H-labeled protein into their regenerating portions distal to the site of injury within a week after injury when placed in vitro. Transport in vitro was not significantly less than transport in axons maintained in vivo for the same period. Transport occurred in the medium that was used by the McLean group, but was significantly reduced in calcium-free medium. When axon regeneration was delared, only small amounts of activity were present in the nerve distal to the site of injury, showing that labeled protein normally present in that part of the nerve was associated with axons and was not a result of local precursor uptake by nonneural elements in the sciatic nerve. We were not able to explain the failure of McLean and co-workers to demonstrate transport in vitro in regenerating vagus nerve, but we conclude that there is no general peculiarity of growing axons that makes them unable to sustain transport in vitro.

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Neurotrophins affect the pattern of DRG neurite growth in a bioassay that presents a choice of CNS and PNS substrates

Development ◽

10.1242/dev.121.5.1301 ◽

1995 ◽

Vol 121 (5) ◽

pp. 1301-1309 ◽

Cited By ~ 1

Author(s):

R. Tuttle ◽

W.D. Matthew

Keyword(s):

Spinal Cord ◽

Central Nervous System ◽

Nervous System ◽

Sciatic Nerve ◽

Sympathetic Neurons ◽

Neurite Growth ◽

Drg Neurons ◽

Substrate Preferences

Neurons can be categorized in terms of where their axons project: within the central nervous system, within the peripheral nervous system, or through both central and peripheral environments. Examples of these categories are cerebellar neurons, sympathetic neurons, and dorsal root ganglion (DRG) neurons, respectively. When explants containing one type of neuron were placed between cryosections of neonatal or adult sciatic nerve and neonatal spinal cord, the neurites exhibited a strong preference for the substrates that they would normally encounter in vivo: cerebellar neurites generally extended only on spinal cord, sympathetic neurites on sciatic nerve, and DRG neurites on both. Neurite growth from DRG neurons has been shown to be stimulated by neurotrophins. To determine whether neurotrophins might also affect the substrate preferences of neurites, DRG were placed between cryosections of neonatal spinal cord and adult sciatic nerve and cultured for 36 to 48 hours in the presence of various neurotrophins. While DRG cultured in NGF-containing media exhibited neurite growth over both spinal cord and sciatic nerve substrates, in the absence of neurotrophins DRG neurites were found almost exclusively on the CNS cryosection. To determine whether these neurotrophin-dependent neurite patterns resulted from the selective survival of subpopulations of DRG neurons with distinct neurite growth characteristics, a type of rescue experiment was performed: DRG cultured in neurotrophin-free medium were fed with NGF-containing medium after 36 hours in vitro and neurite growth examined 24 hours later; most DRG exhibited extensive neurite growth on both peripheral and central nervous system substrates.(ABSTRACT TRUNCATED AT 250 WORDS)

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Mitigation of Direct Neurotoxic Effects of Lidocaine and Amitriptyline by Inhibition of p38 Mitogen-activated Protein Kinase In Vitro and In Vivo

Anesthesiology ◽

10.1097/00000542-200606000-00023 ◽

2006 ◽

Vol 104 (6) ◽

pp. 1266-1273 ◽

Cited By ~ 45

Author(s):

Philipp Lirk ◽

Ingrid Haller ◽

Robert R. Myers ◽

Lars Klimaschewski ◽

Yi-Chuan Kau ◽

...

Keyword(s):

Sciatic Nerve ◽

P38 Mapk ◽

Local Anesthetic ◽

Apoptotic Cell ◽

Mitogen Activated Protein Kinase ◽

Mitogen Activated Protein ◽

P38 Mapk Inhibitor ◽

Mapk Inhibitor

Background Local anesthetic-induced direct neurotoxicity (paresthesia, failure to regain normal sensory and motor function) is a potentially devastating complication of regional anesthesia. Local anesthetics activate the p38 mitogen-activated protein kinase (MAPK) system, which is involved in apoptotic cell death. The authors therefore investigated in vitro (cultured primary sensory neurons) and in vivo (sciatic nerve block model) the potential neuroprotective effect of the p38 MAPK inhibitor SB203580 administered together with a clinical (lidocaine) or investigational (amitriptyline) local anesthetic. Methods Cell survival and mitochondrial depolarization as marker of apoptotic cell death was assessed in rat dorsal root ganglia incubated with lidocaine or amitriptyline either with or without the addition of SB203580. Similarly, in a sciatic nerve block model, the authors assessed wallerian degeneration by light microscopy to detect a potential mitigating effect of MAPK inhibition. Results Lidocaine at 40 mm/approximately 1% and amitriptyline at 100 microm reduce neuron count, but coincubation with the p38 MAPK inhibitor SB203580 at 10 mum significantly reduces cytotoxicity and the number of neurons exhibiting mitochondrial depolarization. Also, wallerian degeneration and demyelination induced by lidocaine (600 mm/approximately 15%) and amitriptyline (10 mm/approximately 0.3%) seem to be mitigated by SB203580. Conclusions The cytotoxic effect of lidocaine and amitriptyline in cultured dorsal root ganglia cells and the nerve degeneration in the rat sciatic nerve model seem, at least in part, to be mediated by apoptosis but seem efficiently blocked by an inhibitor of p38 MAPK, making it conceivable that coinjection might be useful in preventing local anesthetic-induced neurotoxicity.

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N -Phenylethyl Amitriptyline in Rat Sciatic Nerve Blockade

Anesthesiology ◽

10.1097/00000542-200206000-00024 ◽

2002 ◽

Vol 96 (6) ◽

pp. 1435-1442 ◽

Cited By ~ 22

Author(s):

Peter Gerner ◽

Mustafa Mujtaba ◽

Mohammed Khan ◽

Yukari Sudoh ◽

Kamen Vlassakov ◽

...

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Therapeutic Range ◽

Local Anesthetic ◽

Na Channel ◽

Patch Clamp Technique ◽

Rat Sciatic Nerve ◽

Nerve Model

Background The antidepressant amitriptyline is commonly used orally for the treatment of chronic pain, particularly neuropathic pain, which is thought to be caused by high-frequency ectopic discharge. Among its many properties, amitriptyline is a potent Na(+) channel blocker in vitro, has local anesthetic properties in vivo, and confers additional blockade at high stimulus-discharge rates (use-dependent blockade). As with other drug modifications, adding a phenylethyl group to obtain a permanently charged quaternary ammonium derivative may improve these advantageous properties. Methods The electrophysiologic properties of N-phenylethyl amitriptyline were assessed in cultured neuronal GH(3) cells with the whole cell mode of the patch clamp technique, and the therapeutic range and toxicity were evaluated in the rat sciatic nerve model. Results In vitro, N-phenylethyl amitriptyline at 10 microm elicits a greater block of Na(+) channels than amitriptyline (resting block of approximately 90% vs. approximately 15%). This derivative also retains the attribute of amitriptyline in evoking high-degree use-dependent blockade during repetitive pulses. In vivo, duration to full recovery of nociception in the sciatic nerve model was 1,932 +/- 72 min for N-phenylethyl amitriptyline at 2.5 mm (n = 7) versus 72 +/- 3 min for lidocaine at 37 mm (n = 4; mean +/- SEM). However, there was evidence of neurotoxicity at 5 mm. Conclusion N-phenylethyl amitriptyline appears to have a narrow therapeutic range but is much more potent than lidocaine, providing a block duration several times longer than any clinically used local anesthetic. Further work in animal models of neuropathic pain will assess the potential use of this drug.

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Effect of Arecoline on Regeneration of Injured Peripheral Nerves

The American Journal of Chinese Medicine ◽

10.1142/s0192415x13500584 ◽

2013 ◽

Vol 41 (04) ◽

pp. 865-885 ◽

Cited By ~ 4

Author(s):

Sheng-Chi Lee ◽

Chin-Chuan Tsai ◽

Chun-Hsu Yao ◽

Yuan-Man Hsu ◽

Yueh-Sheng Chen ◽

...

Keyword(s):

Sciatic Nerve ◽

Peripheral Nerve ◽

Nerve Regeneration ◽

Peripheral Nerve Regeneration ◽

In Vitro Study ◽

Control Group ◽

Neural Cells ◽

In Vivo Evaluation

The present study provides in vitro and in vivo evaluation of arecoline on peripheral nerve regeneration. In the in vitro study, we found that arecoline at 50 μg/ml could significantly promote the survival and outgrowth of cultured Schwann cells as compared to the controls treated with culture medium only. In the in vivo study, we evaluated peripheral nerve regeneration across a 10-mm gap in the sciatic nerve of the rat, using a silicone rubber nerve chamber filled with the arecoline solution. In the control group, the chambers were filled with normal saline only. At the end of the fourth week, morphometric data revealed that the arecoline-treated group at 5 μg/ml significantly increased the number and the density of myelinated axons as compared to the controls. Immunohistochemical staining in the arecoline-treated animals at 5 μg/ml also showed their neural cells in the L4 and L5 dorsal root ganglia ipsilateral to the injury were strongly retrograde-labeled with fluorogold and lamina I–II regions in the dorsal horn ipsilateral to the injury were significantly calcitonin gene-related peptide-immunolabeled compared with the controls. In addition, we found that the number of macrophages recruited in the distal sciatic nerve was increased as the concentration of arecoline was increased. Electrophysiological measurements showed the arecoline-treated groups at 5 and 50 μg/ml had a relatively larger nerve conductive velocity of the evoked muscle action potentials compared to the controls. These results indicate that arecoline could stimulate local inflammatory conditions, improving the recovery of a severe peripheral nerve injury.

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Ultralong Peripheral Nerve Block by Lidocaine:Prilocaine 1:1 Mixture in a Lipid Depot Formulation

Anesthesiology ◽

10.1097/00000542-200601000-00017 ◽

2006 ◽

Vol 104 (1) ◽

pp. 110-121 ◽

Cited By ~ 23

Author(s):

Lars Söderberg ◽

Henrik Dyhre ◽

Bodil Roth ◽

Sven Björkman

Keyword(s):

Sciatic Nerve ◽

Nerve Block ◽

Local Anesthetic ◽

In Vitro Release ◽

Sciatic Nerve Block ◽

Depot Formulation ◽

Duration Of Action ◽

Depot Preparations

Background The aim of this study was to develop stable and easily injectable lipid depot preparations of local anesthetics in which the drug concentration can be varied according to desired duration of action. Methods The formulations contained a 2.0, 5.0, 10, 20, 40, 60, 80, or 100% eutectic mixture of lidocaine and prilocaine base in medium-chain triglyceride. Duration of sciatic nerve block and local neurotoxicity was investigated in rats with 2.0% lidocaine:prilocaine HCl solution and 99.5% ethanol as controls. The rate of release of local anesthetic from the site of administration and the possibility to predict in vivo depot characteristics from in vitro release data were investigated for the 20 and 60% formulations. Results The duration of sensory sciatic block was prolonged 3 times with the 20% formulation and approximately 180 times with the 60% formulation, in comparison with the 2% aqueous solution. With the 80 and 100% formulations, all animals still showed nerve block after 2 weeks. The in vivo release of local anesthetic could be approximately predicted from in vitro data for the 20% but not for the 60% formulation. The formulations of 60% or greater and ethanol showed neurotoxic effects. Conclusions The pharmaceutical properties of these formulations compare favorably with those of other depot preparations. The high-percentage ones showed the longest duration of action yet reported for sciatic nerve block in rats. The possibility of using a high-concentration local anesthetic depot formulation as an alternative to ethanol or phenol for long-term nerve blocks in chronic pain merits further investigation.

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Protocatechuic acid as an inhibitor of the JNK/CXCL1/CXCR2 pathway relieves neuropathic pain in CCI rats

Bosnian Journal of Basic Medical Sciences ◽

10.17305/bjbms.2021.5928 ◽

2021 ◽

Author(s):

Hong-xia Chang ◽

Yue-feng Zhao

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Satellite Cells ◽

Protocatechuic Acid ◽

Thermal Hyperalgesia ◽

Tnf Α ◽

Chemokine Ligand ◽

New Perspective

Emerging evidence has shown that protocatechuic acid (PCA) has antioxidant and anti-inflammatory effects. Evidence suggests that PCA can alleviate the injury of sciatic nerve, while the mechanism of its therapeutic effect on neuralgia remains unknown. Chromium bowel ligation was used in vivo to establish a chronic constriction injury (CCI) rat model to induce sciatic nerve pain. Subsequently, two doses of PCA were used to treat CCI rats. In vitro, 10 ng/mL TNF-α was used to stimulate glial satellite cells derived from the dorsal root ganglia (DRG) L4-L6 of the sciatic nerve to simulate sciatic nerve pain. PCA relieved mechanical allodynia and thermal hyperalgesia in CCI rats. CCK-8 assay revealed that PCA inhibited the proliferation of glial satellite cells induced by TNF-α. Moreover, ELISA demonstrated that PCA could improve the inflammatory response of rats caused by CCI and cells induced by TNF-α. Next, RT-qPCR and Western blot assays showed that PCA blocked the c-Jun N-terminal kinase/the chemokine ligand 1/CXC chemokine receptor 2 (JNK/CXCL1/CXCR2) pathway by inhibiting CXCL1 levels in cells induced by TNF-α and DRG in CCI rats. In conclusion, PCA can alleviate neuropathic pain in CCI rats and improve oxidative stress by inhibiting the JNK/CXCL1/CXCR2 signaling pathway. Thus, these findings provide a new perspective for the treatment of neuropathic pain caused by CCI.

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p38/TF/HIF-α Signaling Pathway Participates in the Progression of CIPN in Mice

BioMed Research International ◽

10.1155/2019/5347804 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11

Author(s):

Yang Yang ◽

Liang Hu ◽

Chaoyu Wang ◽

Xing Yang ◽

Ling Song ◽

...

Keyword(s):

Sciatic Nerve ◽

Coagulation Factor ◽

Gelatin Zymography ◽

Pathological Process ◽

Macrophage Cell Line ◽

Macrophage Cell ◽

Microcirculatory Disturbance ◽

Molecular Signal

Chemotherapy induced peripheral neuropathy (CIPN) is a serious adverse effect of chemotherapeutics with limited pathogenetic mechanism been known. Whether microcirculatory disturbance is involved in CIPN has not been reported. Considering that tissue factor (TF) is an endogenous coagulation factor, we hypothesize CIPN may be induced by the high expression of TF in macrophages and sciatic nerve, which induces the molecular signal related to ischemia and hypoxia. Oxaliplatin (L-OHP) was used to establish CIPN model. Von Frey Hairs was used to measure nociception. The murine macrophage cell line Raw 264.7 was used for cell experiments. Gelatin zymography and western blotting were used to measure the activity or expression of protein. TF expression and MMP-9/2 activity in sciatic nerve and blood are significantly increased by L-OHP. L-OHP increased the release of HSP70 from macrophage and enhanced the expression of p-p38 and HIF-1α in vivo and in vitro. Hirudin significantly suppressed the overexpression of p38, HIF-1α and activation of MMP-9/2 induced by L-OHP and attenuated CIPN in mice. This study suggests that a novel HSP70-TLR-4-p38-TF-HIF-1a axis may play a pivotal role in the pathological process of CIPN. It is also shown that the use of anticoagulant Hirudin can inhibit the above mechanisms and improve CIPN.

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