Sciatic Nerve Inflammation Research Articles

Autophagy and anti-inflammation ameliorate diabetic neuropathy with Rilmenidine.

To evaluate the neuroprotective effects of Rilmenidine on diabetic peripheral neuropathy (DPN) in a rat model of diabetes induced by streptozotocin (STZ). STZ (60 mg/kg) was administered to adult Sprague-Dawley rats to induce diabetes. On the 30th day after STZ administration, electromyography (EMG) and motor function tests confirmed the presence of DPN. Group 1: Control (n = 10), Group 2: DM + 0.1 mg/kg Rilmenidine (n = 10), and Group 3: DM + 0.2 mg/kg Rilmenidine (n = 10) were administered via oral lavage for four weeks. EMG, motor function test, biochemical analysis, and histological and immunohistochemical analysis of sciatic nerves were then performed. The administration of Rilmenidine to diabetic rats substantially reduced sciatic nerve inflammation and fibrosis and prevented electrophysiological alterations. Immunohistochemistry of sciatic nerves from saline-treated rats revealed increased perineural thickness, HMGB-1, tumor necrosis factor-α, and a decrease in nerve growth factor (NGF), LC-3. In contrast, Rilmendine significantly inhibited inflammation markers and prevented the reduction in NGF expression. In addition, Rilmenidine significantly decreased malondialdehyde and increased diabetic rats' total antioxidative capacity. The findings of this study suggest that Rilmenidine may have therapeutic effects on DNP by modulating antioxidant and autophagic pathways.

Campylobacter jejuni induces autoimmune peripheral neuropathy via Sialoadhesin and Interleukin-4 axes

ABSTRACT Campylobacter jejuni is a leading cause of gastroenteritis that has been causally linked with development of the autoimmune peripheral neuropathy Guillain Barré Syndrome (GBS). Previously, we showed that C. jejuni isolates from human enteritis patients induced Type1/17-cytokine dependent colitis in interleukin-10 (IL-10)−/− mice, while isolates from GBS patients colonized these mice without colitis but instead induced autoantibodies that cross-reacted with the sialylated oligosaccharide motifs on the LOS of GBS-associated C. jejuni and the peripheral nerve gangliosides. We show here that infection of IL-10−/− mice with the GBS but not the colitis isolate led to sciatic nerve inflammation and abnormal gait and hind limb movements, with character and timing consistent with this syndrome in humans. Autoantibody responses and associated nerve histologic changes were dependent on IL-4 production by CD4 T cells. We further show that Siglec-1 served as a central antigen presenting cell receptor mediating the uptake of the GBS isolates via interaction with the sialylated oligosaccharide motifs found specifically on the LOS of GBS-associated C. jejuni, and the ensuing T cell differentiation and autoantibody elicitation. Sialylated oligosaccharide motifs on the LOS of GBS-associated C. jejuni therefore acted as both the Siglec-1-ligand for phagocytosis, as well as the epitope for autoimmunity. Overall, we present a mouse model of an autoimmune disease induced directly by a bacterium that is dependent upon Siglec-1 and IL-4. We also demonstrate the negative regulatory role of IL-10 in C. jejuni induced autoimmunity and provide IL-4 and Siglec-1 blockade as potential therapeutic interventions against GBS.

MBP-activated autoimmunity plays a role in arsenic-induced peripheral neuropathy and the potential protective effect of mecobalamin.

Intake excessive arsenic (As) is related to the occurrence of peripheral neuropathy. However, both the underlying mechanism and the preventive approach remain largely unknown. In the present study, As treatment significantly decreased the mechanical withdrawal threshold and increased the titer of anti-myelin basic protein antibody in rats, accompanied with damaged BNB. The levels of inflammatory cytokines and proteolytic enzymes were also significantly upregulated. However, administration of MeCbl in As-treated rats significantly reversed the decline in hindfoot mechanical withdrawal threshold, as well as BNB failure and sciatic nerve inflammation. Repeated As treatment in athymic nude mice indicated that sciatic nerve inflammation and mechanical hyperalgesia were T cell-dependent. These data implicated that MBP-activated autoimmunity and the related neuroinflammation probably contributed to As-induced mechanical hyperalgesia and MeCbl exerted a protective role probably via maintenance the integrity of BNB and inhibition of neuroinflammation.

Human Neural Stem Cell-Conditioned Medium Inhibits Inflammation in Macrophages Via Sirt-1 Signaling Pathway In Vitro and Promotes Sciatic Nerve Injury Recovery in Rats.

Chronic persistent inflammation is thought to impede axon regeneration and cause demyelinating disease also with neuropathic pain, leading to more severe dysfunction after peripheral nerve injury. Increasing evidence indicates that neural stem cells (NSCs) have immunomodulatory effects, and previous studies have shown that many of the beneficial effects attributed to stem cell therapy may exert their therapeutic effects through paracrine mechanisms. In this research, the repairing effect of NSC-conditioned medium (NSC-CM) on sciatic nerve injury and its mechanism of repair were further explored. The present research showed that NSC-CM promoted histopathological and functional recovery after crush injury in rats, and what counts is that NSC-CM inhibited the inflammation of sciatic nerve in the late stage of injury. NSC-CM significantly downregulated the infiltration of proinflammatory factors [tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and IL-1β] as well as decreased the CD68 inflammatory macrophages infiltrating in the sciatic nerve. In addition, to study the effect of NSC-CM on the inflammatory state of macrophages in vitro, lipopolysaccharide (LPS) was used to induce the proinflammation of macrophages. The results showed that NSC-CM decreased the expression of macrophage proinflammatory-related proteins (IL-6, IL-1β, TNF-α, inducible nitric oxide synthase) induced by LPS. The activation of Sirt-1 signaling in macrophages effectively countered the proinflammation induced by LPS in the presence of NSC-CM. Using Sirt-1-specific inhibitor EX527 partially weakened the anti-inflammatory effect of NSC-CM. Altogether, this study demonstrated for the first time that NSC-CM promotes functional recovery after sciatic nerve crush injury in vivo and also inhibits the inflammation in activated macrophages by activating Sirt-1 signaling pathway in vitro.

Effect of Ayurvedic regimen and Panchakarma technique in the management of Sciatica (Gridhrasi) - A case report.

Sciatica is one of the common conditions of locomotor system disorder, affects people during their productive life. It is defined as inflammation of sciatic nerve, which cause sciatic neuritis. It restricts the leg movement. In Ayurved it is correlated to Gridhrasi. A case study was carried out to assess effect of Internal Ayurvedic regimen, Kala basti in Sciatica (Gridhrasi). As Bastikarma is the most important among the Panchakarma for the management of Vatavyadhi. Here an effort was made to treat a 48 year Female adult with sciatica using multiple ayurveda treatment. At the end of 16th days of treatment, Panchakarma procedures along with internal medication resulted in 90% improvement in overall effect of therapy.

IGF1 affects macrophage invasion and activation and TNF-α production in the sciatic nerves of female SOD1G93A mice

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease leading to paralysis and death within 3–5 years of its diagnosis. The SOD1G93A mouse is used extensively as an ALS animal model. Increasing evidence shows that non-neuronal cellscontribute to the pathogenesis and progression of ALS. Among them, many studies focus on microgliosis in the spinal cord (SC); while few on macrophage activation in the sciatic nerves. Substantial evidence shows that insulin-like growth factor 1 (IGF1) delays disease progression and increases the lifespan of SOD1G93A mice, and some studies indicate that IGF1 reduces inflammation in the SC of ALS mice. However, no studies have focused on the effect of IGF on sciatic nerve inflammation. Here, we find that ALS progression is characterized by increasing macrophage invasion and activation accompanied by significant TNF-α production in the sciatic nerve. Furthermore, IGF1 treatment and knockdown alleviate and aggravate these responses, respectively. Collectively, our findings show the first time that IGF1 has an anti-inflammatory effect in the sciatic nerves of SOD1G93A mice.

Evaluation of Analgesic and Anti-Inflammatory Activity of Mahanimba (Melia Azedarach Linn.) Moola Ghanavati In Albino Rats

The drugs which are used as analgesic and anti inflammatory agents cause many side effects and toxic effects. Many medicines of plant origin have been used from many years without any side effects. In Ayurvedic ancient text named Gada Nigraha, it has been mentioned that Mahanimba (Melia azedarach Linn.) Moola can be used in the management of Gridhrasi (Sciatica). In Gridhrasi pain and inflammation of Sciatic nerve is the main cardinal symptoms. So, in this pharmacological study evaluation of analgesic and anti inflammatory activity of test drug Mahanimba Moola have been assessed with compare to Standard drug Parijata Patra (Nyctanthes arbortristis).

Transplantation of dental pulp stem cells suppressed inflammation in sciatic nerves by promoting macrophage polarization towards anti-inflammation phenotypes and ameliorated diabetic polyneuropathy.

Aims/IntroductionDental pulp stem cells (DPSCs) are thought to be an attractive candidate for cell therapy. We recently reported that the transplantation of DPSCs increased nerve conduction velocity and nerve blood flow in diabetic rats. In the present study, we investigated the immunomodulatory effects of DPSC transplantation on diabetic peripheral nerves.Materials and Methods DPSCs were isolated from the dental pulp of Sprague–Dawley rats and expanded in culture. Eight weeks after the streptozotocin injection, DPSCs were transplanted into the unilateral hindlimb skeletal muscles. Four weeks after DPSC transplantation, neurophysiological measurements, inflammatory gene expressions and the number of CD68‐positive cells in sciatic nerves were assessed. To confirm the immunomodulatory effects of DPSCs, the effects of DPSC‐conditioned media on lipopolysaccharide‐stimulated murine macrophage RAW264.7 cells were investigated.ResultsDiabetic rats showed significant delays in sciatic nerve conduction velocities and decreased sciatic nerve blood flow, all of which were ameliorated by DPSC transplantation. The number of CD68‐positive monocytes/macrophages and the gene expressions of M1 macrophage‐expressed cytokines, tumor necrosis factor‐α and interleukin‐1β, were increased in the sciatic nerves of the diabetic rats. DPSC transplantation significantly decreased monocytes/macrophages and tumor necrosis factor‐α messenger ribonucleic acid expression, and increased the gene expression of the M2 macrophage marker, CD206, in the sciatic nerves of the diabetic rats. The in vitro study showed that DPSC‐conditioned media significantly increased the gene expressions of interleukin‐10 and CD206 in lipopolysaccharide‐stimulated RAW264.7 cells.ConclusionsThese results suggest that DPSC transplantation promoted macrophages polarization towards anti‐inflammatory M2 phenotypes, which might be one of the therapeutic mechanisms for diabetic polyneuropathy.

AAV1.NT-3 gene therapy attenuates spontaneous autoimmune peripheral polyneuropathy.

The spontaneous autoimmune peripheral polyneuropathy (SAPP) model in B7-2 knockout non-obese diabetic mice shares clinical and histological features with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Secondary axonal loss is prominent in the progressive phase of this neuropathy. Neurotrophin 3 (NT-3) is an important autocrine factor supporting Schwann cell survival and differentiation and stimulates neurite outgrowth and myelination. The anti-inflammatory and immunomodulatory effects of NT-3 raised considerations of potential efficacy in the SAPP model that could be applicable to CIDP. For this study, scAAV1.tMCK.NT-3 was delivered to the gastrocnemius muscle of 25-week-old SAPP mice. Measurable NT-3 levels were found in the serum at 7-week postgene delivery. The outcome measures included functional, electrophysiological and histological assessments. At week 32, NT-3-treated mice showed increased hind limb grip strength that correlated with improved compound muscle action potential amplitude. Myelinated fiber density was 1.9 times higher in the NT-3-treated group compared with controls and the number of demyelinated axons was significantly lower. The remyelinated nerve fiber population was significantly increased. These improved histopathological parameters from scAAV1.tMCK.NT-3 treatment occurred in the setting of reduced sciatic nerve inflammation. Collectively, these findings suggest a translational application to CIDP.

Sciatic Neuritis After Lumbar Decompression Surgery

Case report. To report a unique case of sciatica secondary to sciatic neuritis developed after spine decompression surgery. Sciatica may arise within the spinal canal, the pelvis, or along the extrapelvic journey of the nerve. Sciatica after spine surgery is less common and can be secondary to nerve root compression from hematoma, seroma, or abscess. The purpose of this article was to present a unique case of a 68-year-old female with sciatica secondary to sciatic neuritis developed after lumbar decompression surgery complicated by dural tear. A single patient with radicular leg pain after lumbar decompression surgery is reported. Pelvic magnetic resonance imaging revealed marked left sciatic nerve inflammation. The patient showed immediate pain relief after steroid administration. This is the first reported case of sciatica secondary to sciatic neuritis developed after spine decompression surgery.

The protective effect of dexmedetomidine on bupivacaine-induced sciatic nerve inflammation is mediated by mast cells

This study was designed to assess the correlation between the neuroprotective effect of dexmedetomidine and oxidative stress, neural inflammation and mast cell stability in rats with bupivacaine-induced sciatic nerve toxicity. Forty adult Wistar Albino rats, eight rats per group, were used. Saline (0.3 ml of 0.9%), dexmedetomidine (20 µg/kg), 0.5% bupivacaine or 0.5% bupivacaine+dexmedetomidine (20 µg/kg) was injected into the sciatic nerve. A control group of rats received no injection. Fourteen days after injection, the sciatic nerves were harvested and total oxidant status, total anti-oxidant status, paraoxonase-1, galectin-3 and matrix metalloproteinase 2 and 9 levels were measured in the sciatic nerves. In addition, the presence and status of inflammation, edema, and mast cells were evaluated histopathologically. The combination of dexmedetomidine and bupivacaine alleviated oxidative stress. In addition, it decreased matrix metalloproteinase 9 and galectin-3 levels and increased matrix metalloproteinase 2 levels. Moreover, it stabilized recruited mast cells at the injury site; however, it did not significantly decrease inflammation or edema. Dexmedetomidine may ameliorate bupivacaine-induced neurotoxicity by modulating mast cell degranulation. The neuroprotective effect of dexmedetomidine may make it a suitable adjuvant agent to local anesthetics in peripheral nerve blocks.

COMP-Angiopoietin-1 Recovers Molecular Biomarkers of Neuropathy and Improves Vascularisation in Sciatic Nerve of ob/ob Mice

BackgroundLeptin-deficient ob/ob mice are a model of type 2 diabetes induced peripheral neuropathy. Ob/ob mice exhibit obesity, insulin resistance, hyperglycaemia, and alterations of peripheral nerve fibres and endoneural microvessels. Here we test the hypothesis that cartilage oligomeric matrix protein (COMP)-Ang-1, a soluble and stabile form of Ang-1 which promotes angiogenesis and nerve growth, improves regeneration of nerve fibres and endoneural microvessels in ob/ob mice.Methods and FindingsCOMP-Ang-1 (100 ng/ml) or NaCl were intraperitoneally (i.p.) injected into male (N = 184), 3-month old, ob/ob or ob/+ mice for 7 and 21 days. We measured expression of Nf68, GAP43, Cx32, Cx26, Cx43, and TNFα in sciatic nerves using Western blot analysis. To investigate the inflammation in sciatic nerves, numbers of macrophages and T-cells were counted after immunofluorescence staining. In ultrathin section, number of myelinated/non-mylinated nerve fibers, g-ratio, the thickness of Schwann cell basal lamina and microvessel endothelium were investigated.Endoneural microvessels were reconstructed with intracardial FITC injection. Treatment with COMP-Ang-1 over 21 days significantly reduced fasting blood glucose and plasma cholesterol concentrations compared to saline treated ob/ob mice. In addition, COMP-Ang-1 treatment: 1) up-regulated expression of Nf68 and GAP43; 2) improved expression of gap junction proteins including connexin 32 and 26; 3) suppressed the expression of TNFα and Cx43 and 4) led to decreased macrophage and T-cell infiltration in sciatic nerve of ob/ob mice. The significant changes of sciatic nerve ultrastructure were not observed after 21-day long COMP-Ang-1 treatment. COMP-Ang-1 treated ob/ob mice displayed regeneration of small-diameter endoneural microvessels. Effects of COMP-Ang-1 corresponded to increased phosphorylation of Akt and p38 MAPK upon Tie-2 receptor.ConclusionsCOMP-Ang-1 recovers molecular biomarkers of neuropathy, promotes angiogenesis and suppresses inflammation in sciatic nerves of ob/ob mice suggesting COMP-Ang-1 as novel treatment option to improve morphologic and protein expression changes associated with diabetic neuropathy.

Off-balance dorsal position at volleyball service involved in sciatic nerve inflammation

ObjectiveThe aim of the study is to demonstrate that wrong physical position in volleyball service hit is associated with sciatic nerve injuries sustained by young female athletes.DesignObservational study through the...

Involvement of spinal cord nuclear factor κB activation in rat models of proinflammatory cytokine‐mediated pain facilitation

Proinflammatory cytokines, such as interleukin-1beta and tumour necrosis factor-alpha, are released by activated glial cells in the spinal cord and play a major role in pain facilitation. These cytokines exert their actions, at least partially, through the activation of the transcription factor, nuclear factor kappaB (NF-kappaB). In turn, NF-kappaB regulates the transcription of many inflammatory mediators, including cytokines. We have previously shown that intrathecal injection of the human immunodeficiency virus-1 (HIV-1) envelope glycoprotein, gp120, induces mechanical allodynia via the release of proinflammatory cytokines. Here, we investigated whether NF-kappaB is involved in gp120-induced pain behaviour in Sprague-Dawley rats. Intrathecal administration of NF-kappaB inhibitors, pyrrolidinedithiocarbamate (PDTC) and SN50, prior to gp120 partially attenuated gp120-induced allodynia. In addition, PDTC delayed and reversed allodynia in a model of neuropathic pain induced by sciatic nerve inflammation. These observations suggest that intrathecal gp120 may lead to activation of NF-kappaB within the spinal cord. To reveal NF-kappaB activation, we assessed inhibitory factor kappaBalpha (IkappaBalpha) mRNA expression by in situ hybridization, as NF-kappaB activation up-regulates IkappaBalpha gene expression as part of an autoregulatory feedback loop. No or low levels of IkappaBalpha mRNA were detected in the lumbar spinal cord of vehicle-injected rats, whereas IkappaBalpha mRNA expression was markedly induced in the spinal cord following intrathecal gp120 in predominantly astrocytes and endothelial cells. Moreover, IkappaBalpha mRNA expression positively correlated with proinflammatory cytokine protein levels in lumbosacral cerebrospinal fluid. Together, these results demonstrate that spinal cord NF-kappaB activation is involved, at least in part, in exaggerated pain states.

Minocycline attenuates mechanical allodynia and proinflammatory cytokine expression in rat models of pain facilitation

Activated glial cells (microglia and astroglia) in the spinal cord play a major role in mediating enhanced pain states by releasing proinflammatory cytokines and other substances thought to facilitate pain transmission. In the present study, we report that intrathecal administration of minocycline, a selective inhibitor of microglial cell activation, inhibits low threshold mechanical allodynia, as measured by the von Frey test, in two models of pain facilitation. In a rat model of neuropathic pain induced by sciatic nerve inflammation (sciatic inflammatory neuropathy, SIN), minocycline delayed the induction of allodynia in both acute and persistent paradigms. Moreover, minocycline was able to attenuate established SIN-induced allodynia 1 day, but not 1 week later, suggesting a limited role of microglial activation in more perseverative pain states. Our data are consistent with a crucial role for microglial cells in initiating, rather than maintaining, enhanced pain responses. In a model of spinal immune activation by intrathecal HIV-1 gp120, we show that the anti-allodynic effects of minocycline are associated with decreased microglial activation, attenuated mRNA expression of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-1β-converting enzyme, TNF-α-converting enzyme, IL-1 receptor antagonist and IL-10 in lumbar dorsal spinal cord, and reduced IL-1β and TNF-α levels in the CSF. In contrast, no significant effects of minocycline were observed on gp120-induced IL-6 and cyclooxygenase-2 expression in spinal cord or CSF IL-6 levels. Taken together these data highlight the importance of microglial activation in the development of exaggerated pain states.

Spinal gap junctions: Potential involvement in pain facilitation

Abstract Glia are now recognized as important contributors in pathological pain creation and maintenance. Spinal cord glia exhibit extensive gap junctional connectivity, raising the possibility that glia are involved in the contralateral spread of excitation resulting in mirror image pain. In the present experiments, the gap junction decoupler carbenoxolone was administered intrathecally after induction of neuropathic pain in response to sciatic nerve inflammation (sciatic inflammatory neuropathy) or partial nerve injury (chronic constriction injury). In both neuropathic pain models, a low dose of carbenoxolone reversed mirror image mechanical allodynia, while leaving ipsilateral mechanical allodynia unaffected. Ipsilateral thermal hyperalgesia was briefly attenuated. Critically, blockade of mechanical allodynia and thermal hyperalgesia was not observed in response to intrathecal glycyrrhizic acid, a compound similar to carbenoxolone in all respects but it does not decouple gap junctions. Thus, blockade of mechanical allodynia and thermal hyperalgesia by carbenoxolone does appear to reflect an effect on gap junctions. Examination of carbenoxolone's effects on intrathecal human immunodeficiency virus type 1 gp120 showed that blockade of pain facilitation might result, at least in part, via suppression of interleukin-1 and, in turn, interleukin-6. These data provide the first suggestion that spread of excitation via gap junctions might contribute importantly to inflammatory and traumatic neuropathic pain. Perspective The current studies provide evidence for involvement of gap junctions in spinal cord pain facilitation. Intrathecal carbenoxolone, a gap junction decoupler, reversed neuropathy-induced mirror image pain and intrathecal gp120-induced allodynia. In addition, it decreased gp120-induced proinflammatory cytokines. This suggests gap junction activation might lead to proinflammatory cytokine release by distantly activated glia.

Experimental allergic neuritis in Lewis rats: Altered pattern of disease induced by pertussis vaccine

Experimental allergic neuritis (EAN) was induced in Lewis rats by a single injection of sciatic nerve-complete Freund's adjuvant either with or without a simultaneous injection of pertussis vaccine as a supplemental immunopotentiating agent. Fibrin deposition, documented by immunofluorescence and electron microscopy, was found to be an important immunohistopathologic concomitant of this autoimmune peripheral nervous system disorder irrespective of whether pertussis vaccine was included in the sensitization regimen. In contrast to the well-known capacity of pertussis vaccine to accelerate and intensify other analogous experimental autoallergies, Lewis rats receiving pertussis vaccine in addition to peripheral nerve sensitization clearly developed a less intense form and altered pattern of EAN as manifested by: (a) decreased thoracic cage muscular weakness and associated respiratory impairment and (b) decreased sciatic nerve inflammation. Diminished inflammation of sciatic nerves was accompanied by increased fibrin deposition and focal cellular infiltration within the brain. Pertussis vaccine would appear to exert an immunosuppressive effect on EAN while simultaneously retaining its known capacity to augment immunologic injury of the central nervous system.

Novocain block for sciatic nerve inflammation

Extensive experience of Prof. Vishnevsky's clinic in the field of local anesthesia during surgical operations gave extremely valuable clinical observations on the course of a number of pathological processes, the favorable outcome of which could not be explained by anything else than the peculiar effect of the anesthetic solution used in the clinic on the general trophic setting of the nervous system. These observations, which did not fit into the framework of the usual notions, turned out to be possible to generalize and systematize on the basis of the observations and comparisons of the results obtained in a series of clinical experiments.