Dexmedetomidine Improves Locomotor Function and Alleviates Thermal Hyperalgesia Following Sciatic Nerve Crush Injury in Rats

Purpose: The effects of dexmedetomidine on locomotor function and thermal hyperalgesia in sciatic nerve crush injury (SNCI) were investigated using rats.Methods: After exposing the right sciatic nerve, the sciatic nerve was crushed for 1 minute by a surgical clip. One day after nerve injury, dexmedetomidine (5, 25, and 50 µg/kg) was directly applied to the injured sciatic nerve once a day for 14 days. Walking track analysis was used to assess locomotor function and plantar test was conducted to assess thermal pain sensitivity. Immunohistochemistry was performed to determine the expression of c-Fos in the ventrolateral periaqueductal gray (vlPAG) and paraventricular nucleus (PVN). Western blot was used to evaluate the expression level of nerve growth factor (NGF) and myelin basic protein (MBP) in the sciatic nerve.Results: SNCI resulted in deterioration of locomotor function and increased thermal pain sensitivity. The level of c-Fos expression in the PVN and vlPAG was increased and the level of NGF and MBP expression in the sciatic nerve was enhanced by SNCI. Dexmedetomidine treatment improved locomotor function and upregulated expression of NGF and MBP in the sciatic nerve of SNCI. Dexmedetomidine treatment alleviated thermal hyperalgesia and downregulated expression of c-Fos in the vlPAG and PVN after SNCI.Conclusions: Dexmedetomidine may be used as a potential new treatment drug for recovery of locomotion and control of pain in peripheral nerve injury.

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Reduced Renshaw Recurrent Inhibition after Neonatal Sciatic Nerve Crush in Rats

Neural Plasticity ◽

10.1155/2014/786985 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11

Author(s):

Liang Shu ◽

Jingjing Su ◽

Lingyan Jing ◽

Ying Huang ◽

Yu Di ◽

...

Keyword(s):

Spinal Cord ◽

Sciatic Nerve ◽

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Recurrent Inhibition ◽

Crush Injury ◽

Sciatic Nerve Crush ◽

Nerve Crush ◽

Nerve Crush Injury

Renshaw recurrent inhibition (RI) plays an important gated role in spinal motion circuit. Peripheral nerve injury is a common disease in clinic. Our current research was designed to investigate the change of the recurrent inhibitory function in the spinal cord after the peripheral nerve crush injury in neonatal rat. Sciatic nerve crush was performed on 5-day-old rat puppies and the recurrent inhibition between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSR) elicited from the sectioned dorsal roots and recorded either from the LG-S and MG nerves by antidromic stimulation of the synergist muscle nerve. Our results demonstrated that the MSR recorded from both LG-S or MG nerves had larger amplitude and longer latency after neonatal sciatic nerve crush. The RI in both LG-S and MG motoneuron pools was significantly reduced to virtual loss (15–20% of the normal RI size) even after a long recovery period upto 30 weeks after nerve crush. Further, the degree of the RI reduction after tibial nerve crush was much less than that after sciatic nerve crush indicatig that the neuron-muscle disconnection time is vital to the recovery of the spinal neuronal circuit function during reinnervation. In addition, sciatic nerve crush injury did not cause any spinal motor neuron loss but severally damaged peripheral muscle structure and function. In conclusion, our results suggest that peripheral nerve injury during neonatal early development period would cause a more sever spinal cord inhibitory circuit damage, particularly to the Renshaw recurrent inhibition pathway, which might be the target of neuroregeneration therapy.

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Presence and activation of pro-inflammatory macrophages are associated with CRYAB expression in vitro and after peripheral nerve injury

Journal of Neuroinflammation ◽

10.1186/s12974-021-02108-z ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Erin-Mai F. Lim ◽

Vahid Hoghooghi ◽

Kathleen M. Hagen ◽

Kunal Kapoor ◽

Ariana Frederick ◽

...

Keyword(s):

Sciatic Nerve ◽

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Sciatic Nerve Crush ◽

Nerve Crush ◽

Cytokines And Chemokines ◽

Inflammatory Macrophages ◽

Nerve Crush Injury

Abstract Background Inflammation constitutes both positive and negative aspects to recovery following peripheral nerve injury. Following damage to the peripheral nervous system (PNS), immune cells such as macrophages play a beneficial role in creating a supportive environment for regrowing axons by phagocytosing myelin and axonal debris. However, a prolonged inflammatory response after peripheral nerve injury has been implicated in the pathogenesis of negative symptoms like neuropathic pain. Therefore, the post-injury inflammation must be carefully controlled to prevent secondary damage while allowing for regeneration. CRYAB (also known as alphaB-crystallin/HSPB5) is a small heat shock protein that has many protective functions including an immunomodulatory role in mouse models of multiple sclerosis, spinal cord injury, and stroke. Because its expression wanes and rebounds in the early and late periods respectively after PNS damage, and CRYAB null mice with sciatic nerve crush injury display symptoms of pain, we investigated whether CRYAB is involved in the immune response following PNS injury. Methods Sciatic nerve crush injuries were performed in age-matched Cryab knockout (Cryab−/−) and wildtype (WT) female mice. Nerve segments distal to the injury site were processed by immunohistochemistry for macrophages and myelin while protein lysates of the nerves were analyzed for cytokines and chemokines using Luminex and enzyme-linked immunosorbent assay (ELISA). Peritoneal macrophages from the two genotypes were also cultured and polarized into pro-inflammatory or anti-inflammatory phenotypes where their supernatants were analyzed for cytokines and chemokines by ELISA and protein lysates for macrophage antigen presenting markers using western blotting. Results We report that (1) more pro-inflammatory CD16/32+ macrophages are present in the nerves of Cryab−/− mice at days 14 and 21 after sciatic nerve crush-injury compared to WT counterparts, and (2) CRYAB has an immunosuppressive effect on cytokine secretion [interleukin (IL)-β, IL-6, IL-12p40, tumor necrosis factor (TNF)-α] from pro-inflammatory macrophages in vitro. Conclusions CRYAB may play a role in curbing the potentially detrimental pro-inflammatory macrophage response during the late stages of peripheral nerve regeneration.

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Possible role of antioxidative capacity of (−)-epigallocatechin-3-gallate treatment in morphological and neurobehavioral recovery after sciatic nerve crush injury

Journal of Neurosurgery Spine ◽

10.3171/2016.10.spine16218 ◽

2017 ◽

Vol 27 (5) ◽

pp. 593-613 ◽

Cited By ~ 13

Author(s):

Waleed M. Renno ◽

Ludmil Benov ◽

Khalid M. Khan

Keyword(s):

Spinal Cord ◽

Sciatic Nerve ◽

Nerve Injury ◽

Diameter Ratio ◽

Crush Injury ◽

Sciatic Nerve Crush ◽

Axon Diameter ◽

Nerve Crush ◽

Myelin Thickness ◽

Nerve Crush Injury

OBJECTIVEThis study examined the capacity of the major polyphenolic green tea extract (−)-epigallocatechin-3-gallate (EGCG) to suppress oxidative stress and stimulate the recovery and prompt the regeneration of sciatic nerve after crush injury.METHODSAdult male Wistar rats were randomly assigned to one of 4 groups: 1) Naïve, 2) Sham (sham injury, surgical control group), 3) Crush (sciatic nerve crush injury treated with saline), and 4) Crush+EGCG (sciatic nerve crush injury treated with intraperitoneally administered EGCG, 50 mg/kg). All animals were tested for motor and sensory neurobehavioral parameters throughout the study. Sciatic nerve and spinal cord tissues were harvested and processed for morphometric and stereological analysis. For the biochemical assays, the time points were Day 1, Day 7, Day 14, and Day 28 after nerve injury.RESULTSAfter sciatic nerve crush injury, the EGCG-treated animals (Crush+EGCG group) showed significantly better recovery of foot position and toe spread and 50% greater improvement in motor recovery than the saline-treated animals (Crush group). The Crush+EGCG group displayed an early hopping response at the beginning of the 3rd week postinjury. Animals in the Crush+EGCG group also showed a significant reduction in mechanical allodynia and hyperalgesia latencies and significant improvement in recovery from nociception deficits in both heat withdrawal and tail flick withdrawal latencies compared with the Crush group. In both the Crush+EGCG and Crush groups, quantitative evaluation revealed significant morphological evidence of neuroregeneration according to the following parameters: mean cross-sectional area of axons, myelin thickness in the sciatic nerve (from Week 4 to Week 8), increase of myelin basic protein concentration and gene expression in both the injured sciatic nerve and spinal cord, and fiber diameter to axon diameter ratio and myelin thickness to axon diameter ratio at Week 2 after sciatic nerve injury. However, the axon area remained much smaller in both the Crush+EGCG and Crush groups compared with the Sham and Naïve groups. The number of axons per unit area was significantly decreased in the Crush+EGCG and Crush groups compared with controls. Sciatic nerve injury produced generalized oxidative stress manifested as a significant increase of isoprostanes in the urine and decrease of the total antioxidant capacity (TAC) of the blood from Day 7 until Day 14. EGCG-treated rats showed significantly less increase of isoprostanes than saline-treated animals and also showed full recovery of TAC levels by Day 14 after nerve injury. In spinal cord tissue analysis, EGCG-treated animals showed induced glutathione reductase and suppressed induction of heme oxygenase 1 gene expression compared with nontreated animals.CONCLUSIONSEGCG treatment suppressed the crush-induced production of isoprostanes and stimulated the recovery of the TAC and was associated with remarkable alleviation of motor and sensory impairment and significant histomorphological evidence of neuronal regeneration following sciatic nerve crush injury in rats. The findings of this study suggest that EGCG can be used as an adjunctive therapeutic remedy for nerve injury. However, further investigations are needed to establish the antioxidative mechanism involved in the regenerative process after nerve injury. Only upregulation of glutathione reductase supports the idea that EGCG is acting indirectly via induction of enzymes or transcription factors.

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Dexamethasone Enhanced Functional Recovery after Sciatic Nerve Crush Injury in Rats

BioMed Research International ◽

10.1155/2015/627923 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 18

Author(s):

Xinhong Feng ◽

Wei Yuan

Keyword(s):

Sciatic Nerve ◽

Nerve Injury ◽

Muscle Mass ◽

Functional Recovery ◽

Rat Model ◽

Gastrocnemius Muscle ◽

Sciatic Nerve Crush ◽

Mass Ratio ◽

Nerve Crush ◽

Nerve Crush Injury

Dexamethasone is currently used for the treatment of peripheral nerve injury, but its mechanisms of action are not completely understood. Inflammation/immune response at the site of nerve lesion is known to be an essential trigger of the pathological changes that have a critical impact on nerve repair and regeneration. In this study, we observed the effects of various doses of dexamethasone on the functional recovery after sciatic nerve crush injury in a rat model. Motor functional recovery was monitored by walking track analysis and gastrocnemius muscle mass ratio. The myelinated axon number was counted by morphometric analysis. Rats administered dexamethasone by local intramuscular injection had a higher nerve function index value, increased gastrocnemius muscle mass ratio, reduced Wallerian degeneration severity, and enhanced regenerated myelinated nerve fibers. Immunohistochemical analysis was performed for CD3 expression, which is a marker for T-cell activation, and infiltration in the sciatic nerve. Dexamethasone-injected rats had fewer CD3-positive cells compared to controls. Furthermore, we found increased expression of GAP-43, which is a factor associated with development and plasticity of the nervous system, in rat nerves receiving dexamethasone. These results provide strong evidence that dexamethasone enhances sciatic nerve regeneration and function recovery in a rat model of sciatic nerve injury through immunosuppressive and potential neurotrophic effects.

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Catfish Epidermal Preparation Accelerates Healing of Damaged Nerve in a Sciatic Nerve Crush Injury Rat Model

Frontiers in Pharmacology ◽

10.3389/fphar.2021.632028 ◽

2021 ◽

Vol 12 ◽

Author(s):

Waleed M. Renno ◽

Mohammad Afzal ◽

Bincy Paul ◽

Divya Nair ◽

Jijin Kumar ◽

...

Keyword(s):

Sciatic Nerve ◽

Nerve Injury ◽

Axonal Regeneration ◽

Crush Injury ◽

Male Rats ◽

Sciatic Nerve Crush ◽

Spinal Neurons ◽

Nerve Crush ◽

Neurobehavioral Deficits ◽

Nerve Crush Injury

Preliminary investigations showed that preparations from Arabian Gulf catfish (Arius bilineatus, Val) epidermal gel secretion (PCEGS) exhibit potent anti-inflammatory and healing properties as shown in our previous clinical trials for the healing of non-healing diabetic foot ulcers, chronic back pain, and some other neurological disorders. Here, we report for the first time a unique preparation containing only proteins and lipids (soluble protein fraction B, SPF-FB), derived from the PCEGS accelerated the healing and recovery of sensory-motor functions of experimental sciatic nerve crush injury in rats with its unique neuroprotective and neuroregenerative properties on the spinal neurons and peripheral nerve fibers. Male rats were randomly assigned to five groups: (I) NAÏVE, (II) SHAM, (III) CRUSH treated with saline, (IV) CRUSH + SPF-FB treated with 3 mg/kg intraperitoneally (IP) and (V) CRUSH + SPF-FB treated with 6 mg/kg subcutaneously (SC) groups. The crush groups III, IV and V underwent sciatic nerve crush injury, followed by treatment daily for 14 days with saline, SPF-FB IP and SPF-FB SC. All animals were tested for the neurobehavioral parameters throughout the 6 weeks of the study. Sciatic nerve and spinal cord tissues were processed for light and electron histological examinations, stereological analysis, immunohistochemical and biochemical examinations at Week 4 and Week 6 post-injury. Administration of SPF-FB IP or SC significantly enhanced the neurobehavioral sensory and motor performance and histomorphological neuroregeneration of the sciatic nerve-injured rats. The stereological evaluation of the axon area, average axon perimeters, and myelin thickness revealed significant histomorphological evidence of neuroregeneration in the FB-treated sciatic nerve crush injured groups compared to controls at 4 and 6 weeks. SPF-FB treatment significantly prevented the increased in NeuN-immunoreactive neurons, increased GFAP immunoreactive astrocytes, and decreased GAP-43. We conclude that SPF-FB treatment lessens neurobehavioral deficits, enhances axonal regeneration following nerve injury. We conclude that SPF-FB treatment lessens neurobehavioral deficits and enhances axonal regeneration following nerve injury, as well as protects spinal neurons and enhances subcellular recovery by increasing astrocytic activity and decreasing GAP-43 expression.

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Muscle-derived GDNF facilitates motor nerve recovery following sciatic nerve crush injury

Journal of the American College of Surgeons ◽

10.1016/j.jamcollsurg.2007.06.230 ◽

2007 ◽

Vol 205 (3) ◽

pp. S92

Author(s):

Terence M. Myckatyn ◽

Christina Kenney ◽

Alice Tong ◽

Jessica Duan ◽

Daniel Hunter ◽

...

Keyword(s):

Sciatic Nerve ◽

Motor Nerve ◽

Crush Injury ◽

Sciatic Nerve Crush ◽

Nerve Crush ◽

Nerve Recovery ◽

Nerve Crush Injury

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Functional Recovery and Vitamin E Level Following Sciatic Nerve Crush Injury in Normal and Diabetic Rats

International Journal of Neuroscience ◽

10.3109/00207459808986472 ◽

1998 ◽

Vol 96 (3-4) ◽

pp. 245-254 ◽

Cited By ~ 10

Author(s):

Khalaf Al Moutaery ◽

Mohammed Arshaduddin ◽

Mohammad Tariq ◽

Saleh Al Deeb

Keyword(s):

Vitamin E ◽

Sciatic Nerve ◽

Functional Recovery ◽

Diabetic Rats ◽

Crush Injury ◽

Sciatic Nerve Crush ◽

Nerve Crush ◽

Nerve Crush Injury

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Canine Adipose-Derived Mesenchymal Stromal Cells Enhance Neuroregeneration in a Rat Model of Sciatic Nerve Crush Injury

Cell Transplantation ◽

10.1177/0963689718809045 ◽

2018 ◽

Vol 28 (1) ◽

pp. 47-54 ◽

Cited By ~ 7

Author(s):

Diego Noé Rodríguez Sánchez ◽

Luiz Antonio de Lima Resende ◽

Giovana Boff Araujo Pinto ◽

Ana Lívia de Carvalho Bovolato ◽

Fábio Sossai Possebon ◽

...

Keyword(s):

Sciatic Nerve ◽

Mesenchymal Stromal Cells ◽

Rat Model ◽

Stromal Cells ◽

Multipotent Mesenchymal Stromal Cells ◽

Crush Injury ◽

Sciatic Nerve Crush ◽

Muscle Weight ◽

Nerve Crush ◽

Nerve Crush Injury

Crush injuries in peripheral nerves are frequent and induce long-term disability with motor and sensory deficits. Due to axonal and myelin sheath disruptions, strategies for optimized axonal regeneration are needed. Multipotent mesenchymal stromal cells (MSC) are promising because of their anti-inflammatory properties and secretion of neurotrophins. The present study investigated the effect of canine adipose tissue MSC (Ad-MSC) transplantation in an experimental sciatic nerve crush injury. Wistar rats were divided into three groups: sham ( n = 8); Crush+PBS ( n = 8); Crush+MSC ( n = 8). Measurements of sciatic nerve functional index (SFI), muscle mass, and electromyography (EMG) were performed. Canine Ad-MSC showed mesodermal characteristics (CD34-, CD45-, CD44+, CD90+ and CD105+) and multipotentiality due to chondrogenic, adipogenic, and osteogenic differentiation. SFI during weeks 3 and 4 was significantly higher in the Crush+MSC group ( p < 0.001). During week 4, the EMG latency in the Crush+MSC groups had better near normality ( p < 0.05). The EMG amplitude showed results close to normality during week 4 in the Crush+MSC group ( p < 0.04). There were no statistical differences in muscle weight between the groups ( p > 0.05), but there was a tendency toward weight gain in the Crush+MSC groups. Better motor functional recovery after crush and perineural canine Ad-MSC transplantation was observed during week 2. This was maintained till week 4. In conclusion, the canine Ad-MSC transplantation showed early pro-regenerative effects between 2–4 weeks in the rat model of sciatic nerve crush injury.

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