RESUMO
We reported a 61-year-old man presented with 10-month progressing left sciatic neuropathy and 10-day right facial neuropathy. Serum amphiphysin-IgG was positive. 18F-FDG PET/CT of the whole body showed no signs of malignancy. Treatment with plasma exchange and oral prednisone relieved the symptoms. Nine months later, right hemiparesis and seizure of right limbs developed. 18F-FDG and 18F-PBR06 (18 kDa translocator protein, TSPO) radioligand PET/MRI of the whole body revealed intense uptake in the intracranial lesions. Intracranial lymphoma was diagnosed by stereotactic needle brain biopsy. Mononeuropathies could be paraneoplastic syndromes. TSPO shows high uptake in intracranial lymphoma on 18F-PBR06 PET images.
Assuntos
Neoplasias do Sistema Nervoso Central , Doenças do Nervo Facial , Linfoma , Neuropatia Ciática , Humanos , Masculino , Pessoa de Meia-Idade , Encéfalo/imunologia , Doenças do Nervo Facial/etiologia , Doenças do Nervo Facial/imunologia , Doenças do Nervo Facial/terapia , Fluordesoxiglucose F18 , Imunoglobulina G/imunologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Receptores de GABA/metabolismo , Neuropatia Ciática/etiologia , Neuropatia Ciática/imunologia , Neuropatia Ciática/terapia , Neoplasias do Sistema Nervoso Central/complicações , Neoplasias do Sistema Nervoso Central/diagnóstico por imagem , Neoplasias do Sistema Nervoso Central/imunologia , Doenças Autoimunes/etiologia , Doenças Autoimunes/imunologia , Linfoma/complicações , Linfoma/diagnóstico por imagem , Linfoma/imunologia , Polineuropatia Paraneoplásica/etiologia , Polineuropatia Paraneoplásica/imunologia , Prednisona/uso terapêutico , Glucocorticoides/uso terapêutico , Troca Plasmática , Proteínas do Tecido Nervoso/imunologiaRESUMO
Interleukin-4 (IL-4) has garnered interest as a cytokine that mediates regeneration across multiple tissues including peripheral nerve. Within nerve, we previously showed endogenous IL-4 was critical to regeneration across nerve gaps. Here, we determined a generalizable role of IL-4 in nerve injury and regeneration. In wild-type (WT) mice receiving a sciatic nerve crush, IL-4 expressing cells preferentially accumulated within the injured nerve compared to affected sites proximal, such as dorsal root ganglia (DRGs), or distal muscle. Immunohistochemistry and flow cytometry confirmed that eosinophils (CD45+, CD11b+, CD64-, Siglec-F+) were sources of IL-4 expression. Examination of targets for IL-4 within nerve revealed macrophages, as well as subsets of neurons expressed IL-4R, while Schwann cells expressed limited IL-4R. Dorsal root ganglia cultures were exposed to IL-4 and demonstrated an increased proportion of neurons that extended axons compared to cultures without IL-4 (control), as well as longer myelinated axons compared to cultures without IL-4. The role of endogenous IL-4 during nerve injury and regeneration in vivo was assessed following a sciatic nerve crush using IL-4 knockout (KO) mice. Loss of IL-4 affected macrophage accumulation within injured nerve compared to WT mice, as well as shifted macrophage phenotype towards a CD206- phenotype with altered gene expression. Furthermore, this loss of IL-4 delayed initial axon regeneration from the injury crush site and subsequently delayed functional recovery and re-innervation of neuromuscular junctions compared to wild-type mice. Given the role of endogenous IL-4 in nerve regeneration, exogenous IL-4 was administered daily to WT mice following a nerve crush to examine regeneration. Daily IL-4 administration increased early axonal extension and CD206+ macrophage accumulation but did not alter functional recovery compared to untreated mice. Our data demonstrate IL-4 promotes nerve regeneration and recovery after injury.
Assuntos
Interleucina-4/administração & dosagem , Interleucina-4/biossíntese , Regeneração Nervosa/fisiologia , Neuropatia Ciática/metabolismo , Animais , Células Cultivadas , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Eosinófilos/metabolismo , Gânglios Espinais/imunologia , Gânglios Espinais/metabolismo , Regulação da Expressão Gênica , Injeções Intraperitoneais , Interleucina-4/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Compressão Nervosa/tendências , Regeneração Nervosa/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores de Interleucina-4/biossíntese , Receptores de Interleucina-4/imunologia , Neuropatia Ciática/tratamento farmacológico , Neuropatia Ciática/imunologiaRESUMO
One of the changes brought about by Wallerian degeneration distal to nerve injury is disintegration of axonal mitochondria and consequent leakage of mitochondrial DNA (mtDNA)-the natural ligand for the toll-like receptor 9 (TLR9). RT-PCR and immunohistochemical or Western blot analyses were used to detect TLR9 mRNA and protein respectively in the lumbar (L4-L5) and cervical (C7-C8) dorsal root ganglia (DRG) ipsilateral and contralateral to a sterile unilateral sciatic nerve compression or transection. The unilateral sciatic nerve lesions led to bilateral increases in levels of both TLR9 mRNA and protein not only in the lumbar but also in the remote cervical DRG compared with naive or sham-operated controls. This upregulation of TLR9 was linked to activation of the Nuclear Factor kappa B (NFκB) and nuclear translocation of the Signal Transducer and Activator of Transcription 3 (STAT3), implying innate neuronal immune reaction and a pro-regenerative state in uninjured primary sensory neurons of the cervical DRG. The relationship of TLR9 to the induction of a pro-regenerative state in the cervical DRG neurons was confirmed by the shorter lengths of regenerated axons distal to ulnar nerve crush following a previous sciatic nerve lesion and intrathecal chloroquine injection compared with control rats. The results suggest that a systemic innate immune reaction not only triggers the regenerative state of axotomized DRG neurons but also induces a pro-regenerative state further along the neural axis after unilateral nerve injury.
Assuntos
Gânglios Espinais/citologia , Imunidade Inata/imunologia , Neurônios/citologia , Neurônios/imunologia , Fator de Transcrição STAT3/metabolismo , Neuropatia Ciática/terapia , Receptor Toll-Like 9/metabolismo , Animais , Masculino , Ratos , Ratos Wistar , Fator de Transcrição STAT3/genética , Neuropatia Ciática/imunologia , Neuropatia Ciática/metabolismo , Neuropatia Ciática/patologia , Receptor Toll-Like 9/genéticaRESUMO
Peripheral compressive neuropathy causes significant neuropathic pain, muscle weakness and prolong neuroinflammation. Surgical decompression remains the gold standard of treatment but the outcome is suboptimal with a high recurrence rate. From mechanical compression to chemical propagation of the local inflammatory signals, little is known about the distinct neuropathologic patterns and the genetic signatures after nerve decompression. In this study, controllable mechanical constriction forces over rat sciatic nerve induces irreversible sensorimotor dysfunction with sustained local neuroinflammation, even 4 weeks after nerve release. Significant gene upregulations are found in the dorsal root ganglia, regarding inflammatory, proapoptotic and neuropathic pain signals. Genetic profiling of neuroinflammation at the local injured nerve reveals persistent upregulation of multiple genes involving oxysterol metabolism, neuronal apoptosis, and proliferation after nerve release. Further validation of the independent roles of each signal pathway will contribute to molecular therapies for compressive neuropathy in the future.
Assuntos
Lesões por Esmagamento/patologia , Descompressão Cirúrgica , Neuropatia Ciática/patologia , Animais , Axônios/patologia , Constrição , Lesões por Esmagamento/genética , Lesões por Esmagamento/imunologia , Lesões por Esmagamento/cirurgia , Denervação , Gânglios Espinais/patologia , Perfilação da Expressão Gênica , Hiperalgesia/etiologia , Imunidade Inata , Inflamação , Masculino , Músculo Esquelético/inervação , Músculo Esquelético/patologia , Atrofia Muscular/etiologia , Neuralgia/etiologia , Período Pós-Operatório , Ratos , Ratos Sprague-Dawley , Remielinização , Neuropatia Ciática/genética , Neuropatia Ciática/imunologia , Neuropatia Ciática/cirurgiaRESUMO
AIMS: Inflammation plays a key role in peripheral nerve adhesion and often leads to severe pain and nerve dysfunction. Minocycline was reported to have potent anti-inflammatory effects and might be a promising drug to prevent or attenuate peripheral nerve adhesion. The present study aimed to clarify whether minocycline contributes to nerve adhesion protection and its underlying mechanism. MATERIALS AND METHODS: Rats with sciatic nerve adhesion induced by glutaraldehyde glue (GG) were intraperitoneally injected with minocycline or saline every 12 h for 7 consecutive days. After that, the adhesion score, Ashcroft score, demyelination, macrophage polarization and inflammatory factors in peripheral nerve adhesion tissues or tissues in sham group were determined with histological staining, western blot and real time-PCR. Murine macrophage RAW264.7 cells were stimulated by LPS alone or together with minocycline at different concentrations and time duration to study the mechanism of minocycline in alleviating nerve adhesion. KEY FINDINGS: We found that minocycline treatment reduced the adhesion score, Ashcroft score, the growth of scar tissue, demyelination, and macrophage recruitment. Moreover, minocycline significantly and dose-dependently promoted regulatory macrophage polarization but decreased pro-inflammatory macrophage polarization. Furthermore, mechanism studies showed that TAK1 and its downstream pathway p38/JNK/ERK1/2/p65 were inhibited by minocycline, which led to lower IL-1ß and TNFα expression, but increased IL-10 expression. SIGNIFICANCE: Altogether, these results suggest that minocycline is highly effective against peripheral nerve adhesion through anti-fibrosis, anti-inflammation, and myelination protection, making it a highly promising candidate for treating adhesion-related disorders.
Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , MAP Quinase Quinase Quinases/metabolismo , Ativação de Macrófagos/imunologia , Minociclina/farmacologia , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Neuropatia Ciática/tratamento farmacológico , Aderências Teciduais/prevenção & controle , Animais , Antibacterianos/farmacologia , Modelos Animais de Doenças , Feminino , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , MAP Quinase Quinase Quinases/genética , Ativação de Macrófagos/efeitos dos fármacos , Doenças do Sistema Nervoso Periférico/imunologia , Doenças do Sistema Nervoso Periférico/metabolismo , Doenças do Sistema Nervoso Periférico/patologia , Ratos , Ratos Sprague-Dawley , Neuropatia Ciática/imunologia , Neuropatia Ciática/metabolismo , Neuropatia Ciática/patologiaRESUMO
Guillain-Barré Syndrome (GBS), characterized by peripheral nerve demyelination and axonal damage, is initiated and aggravated through various of immunopathogenesis. Ginsenoside Rd, main active components extracted from ginseng saponins, is known to exhibit immune-regulate functions in many immune-mediated diseases. However, the evidence of preventive effect of Ginsenoside Rd on GBS is lacking. Experimental autoimmune neuritis (EAN) mice, classic model of GBS, were established and treated with GSRd or vehicle. Clinical score and nerve tissue histomorphology were evaluated. Monocytes in peripheral blood and tissue were detected by flow cytometry analysis and immunofluorescence staining. For the in vitro study, GSRd and vehicle were added in the culture medium to assess their regulatory function on monocytes phenotype. In vivo data showed a protective role of GSRd on alleviating symptoms and tissue damage on Day 20 and 25. Administration of GSRd increased non-classical Ly6Clo monocytes in both peripheral blood and injured nerve tissue, and also switched tissue macrophages phenotype into resolution-phase. In vitro study indicated similar role of GSRd on monocytes differentiation status. Transcription factors like Nr4a1 were elevated after GSRd treatment. These findings revealed the protective role of GSRd against EAN, and potential preventive function on GBS patients.
Assuntos
Ginsenosídeos/uso terapêutico , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Neurite Autoimune Experimental/tratamento farmacológico , Neurite Autoimune Experimental/imunologia , Panax , Sequência de Aminoácidos , Animais , Relação Dose-Resposta a Droga , Ginsenosídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/imunologia , Neuropatia Ciática/tratamento farmacológico , Neuropatia Ciática/imunologiaRESUMO
Ablation/segmental loss peripheral nerve injuries (PNIs) exhibit poor functional recovery due to slow and inaccurate outgrowth of regenerating axons. Viable peripheral nerve allografts (PNAs) as growth-guide conduits are immunologically rejected and all anucleated donor/host axonal segments undergo Wallerian degeneration. In contrast, we report that ablation-type sciatic PNIs repaired by neurorrhaphy of viable sciatic PNAs and a polyethylene glycol (PEG)-fusion protocol using PEG immediately restored axonal continuity for many axons, reinnervated/maintained their neuromuscular junctions, and prevented much Wallerian degeneration. PEG-fused PNAs permanently restored many sciatic-mediated behaviors within 2-6 weeks. PEG-fused PNAs were not rejected even though host/donors were neither immunosuppressed nor tissue-matched in outbred female Sprague Dawley rats. Innate and adaptive immune responses to PEG-fused sciatic PNAs were analyzed using electron microscopy, immunohistochemistry, and quantitative reverse transcription polymerase chain reaction for morphological features, T cell and macrophage infiltration, major histocompatibility complex (MHC) expression, apoptosis, expression of cytokines, chemokines, and cytotoxic effectors. PEG-fused PNAs exhibited attenuated innate and adaptive immune responses by 14-21 days postoperatively, as evidenced by (a) many axons and cells remaining viable, (b) significantly reduced infiltration of cytotoxic and total T cells and macrophages, (c) significantly reduced expression of inflammatory cytokines, chemokines, and MHC proteins, (d) consistently low apoptotic response. Morphologically and/or biochemically, PEG-fused sciatic PNAs often resembled sciatic autografts or intact sciatic nerves. In brief, PEG-fused PNAs are an unstudied, perhaps unique, example of immune tolerance of viable allograft tissue in a nonimmune-privileged environment and could greatly improve the clinical outcomes for PNIs relative to current protocols.
Assuntos
Imunidade Adaptativa/fisiologia , Imunidade Inata/fisiologia , Polietilenoglicóis/administração & dosagem , Nervo Isquiático/imunologia , Nervo Isquiático/transplante , Neuropatia Ciática/terapia , Imunidade Adaptativa/efeitos dos fármacos , Aloenxertos/imunologia , Aloenxertos/transplante , Animais , Feminino , Imunidade Inata/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , Neuropatia Ciática/imunologia , Transplante Homólogo/métodosRESUMO
INTRODUCTION: The immuno-microenvironment of injured nerves adversely affects mesenchymal stem cell (MSC) therapy for neurotmesis. Magnetic resonance imaging (MRI) can be used noninvasively to monitor nerve degeneration and regeneration. The aim of this study was to investigate nerve repair after MSC transplantation combined with microenvironment immunomodulation in neurotmesis by using multiparametric MRI. METHODS: Rats with sciatic nerve transection and surgical coaptation were treated with MSCs combined with immunomodulation or MSCs alone. Serial multiparametric MRI examinations were performed over an 8-week period after surgery. RESULTS: Nerves treated with MSCs combined with immunomodulation showed better functional recovery, rapid recovery of nerve T2, fractional anisotropy and radial diffusivity values, and more rapid restoration of the fiber tracks than nerves treated with MSCs alone. DISCUSSION: Transplantation of MSCs in combination with immunomodulation can exert a synergistic repair effect on neurotmesis, which can be monitored by multiparametric MRI.
Assuntos
Imunomodulação/fisiologia , Imageamento por Ressonância Magnética/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Neuropatia Ciática/diagnóstico por imagem , Traumatismos do Sistema Nervoso/diagnóstico por imagem , Animais , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Neuropatia Ciática/imunologia , Neuropatia Ciática/terapia , Traumatismos do Sistema Nervoso/imunologia , Traumatismos do Sistema Nervoso/terapiaRESUMO
Neuropathic pain is a widespread and debilitating chronic pain and the treatment remains a clinical challenge. Isoorientin (3',4',5,7-tetrahydroxy-6-C-glucopyranosyl flavone) is a natural flavonoid-like compound that exhibits antioxidant and anti-inflammatory activities; however, its effect on neuropathic pain remains unclear. Our study aimed to evaluate the antinociceptive effect of isoorientin in neuropathic pain mouse models induced by chronic constriction injury (CCI). In our study, the mice with CCI were administered with 7.5, 15, and, 30â¯mg/kg isoorientin for 8 consecutive days. Behavioral parameters were assayed on days 0, 7, 8, 10, 12, and 14 post-CCI surgery. Electrophysiological, histopathological, and biochemical indices were analyzed on day 14. Immunofluorescence was utilized to examine matrix metalloproteinase-9 (MMP-9) and glial cell activation, and proinflammatory cytokine expression levels were detected via Western blot. It is obvious that the treatment of Isoorientin remarkably ameliorated hyperalgesia and allodynia, increased sensory nerve conduction velocities, and restored CCI-induced sciatic nerve damage in mice. Isoorientin treatment significantly increased the total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD) and catalase (CAT) levels, and decreased the malondialdehyde (MDA) concentrations. Isoorientin also suppressed MMP-9 and glial cell activation, and downregulated tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) expression levels. Therefore, this study provided a novel approach for neuropathic pain treatment and new insights into the pharmacological action of isoorientin.
Assuntos
Analgésicos/uso terapêutico , Hiperalgesia/tratamento farmacológico , Luteolina/uso terapêutico , Neuralgia/tratamento farmacológico , Neuropatia Ciática/tratamento farmacológico , Analgésicos/farmacologia , Animais , Astrócitos/efeitos dos fármacos , Citocinas/imunologia , Hiperalgesia/imunologia , Hiperalgesia/patologia , Hiperalgesia/fisiopatologia , Luteolina/farmacologia , Masculino , Metaloproteinase 9 da Matriz/imunologia , Camundongos Endogâmicos ICR , Microglia/efeitos dos fármacos , Neuralgia/imunologia , Neuralgia/patologia , Neuralgia/fisiopatologia , Nervo Isquiático/lesões , Nervo Isquiático/patologia , Nervo Isquiático/fisiologia , Neuropatia Ciática/imunologia , Neuropatia Ciática/fisiopatologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/imunologiaRESUMO
Peripheral nerve sheath tumors are benign tumors that have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs). Interleukin-13 receptor alpha 2 (IL13Rα2) is a cancer associated receptor expressed in glioblastoma and other invasive cancers. We analyzed IL13Rα2 expression in several MPNST cell lines including the STS26T cell line, as well as in several peripheral nerve sheath tumors to utilize the IL13Rα2 receptor as a target for therapy. In our studies, we demonstrated the selective expression of IL13Rα2 in several peripheral nerve sheath tumors by immunohistochemistry (IHC) and immunoblots. We established a sciatic nerve MPNST mouse model in NIH III nude mice using a luciferase transfected STS26T MPNST cell line. Similarly, analysis of the mouse sciatic nerves after tumor induction revealed significant expression of IL13Rα2 by IHC when compared to a normal sciatic nerve. IL13 conjugated liposomal doxorubicin was formulated and shown to bind and internalized in the MPNST cell culture model demonstrating cytotoxic effect. Our subsequent in vivo investigation in the STS26T MPNST sciatic nerve tumor model indicated that IL13 conjugated liposomal doxorubicin (IL13LIPDXR) was more effective in inhibiting tumor progression compared to unconjugated liposomal doxorubicin (LIPDXR). This further supports that IL13 receptor targeted nanoliposomes is a potential approach for treating MPNSTs.
Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Doxorrubicina/análogos & derivados , Neoplasias de Bainha Neural/tratamento farmacológico , Animais , Antibióticos Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacocinética , Sistemas de Liberação de Medicamentos , Humanos , Imuno-Histoquímica , Interleucina-13/administração & dosagem , Subunidade alfa2 de Receptor de Interleucina-13/metabolismo , Antígeno Ki-67/metabolismo , Camundongos , Camundongos Nus , Neoplasias de Bainha Neural/imunologia , Neoplasias de Bainha Neural/metabolismo , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/farmacocinética , Proteínas S100/metabolismo , Neuropatia Ciática/tratamento farmacológico , Neuropatia Ciática/imunologia , Neuropatia Ciática/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Toll-like receptors (TLRs) are extremely significant pattern recognition receptors. When nerve injury occurs, a variety of inflammatory factors are generated, leading to an exceedingly complex micro-environment. TLRs recognize damage-associated molecular patterns. To investigate the correlation between TLR4 and recovery after sciatic nerve injury, the model of sciatic nerve injury was conducted using TLR4-mutated mice (C3H/HeJ) and wild mice (C3H/HeN). Our goal was to identify short-stage and long-stage changes after sciatic nerve injury, mainly by checking the expression changes of inflammation factors in the short-stage and the differences in the recovery of the injured sciatic nerve in the long-stage. The results show that the increase of changes in the HeN group of IL-1ß, IL-6, TNF-α and MCP-1 are more obvious than in the HeJ group, with caspase1 expression higher and Nlrp3 expression lower in the former group. Further results reveal intense inflammation occurred in the HeN group showing more neutrophils and macrophages. Nlrp3 and caspase1 showed little difference by Immunohistochemistry, with Nlrp6 expression differing between the HeJ group and the HeN group. The results led us to conclude that better recovery of the injured sciatic nerve occurred in the HeJ group because the expression of GAP-43 and p75NTR was higher and had a better SFI figure. TLR4 mutation can decrease the expression of inflammatory factors and enhance the speed of recovery after sciatic nerve injury. The changes in the expression of Nlrp6, which are related to the TLR4 mutation, may influence recovery of the injured sciatic nerve. Further studies will be conducted to confirm these results.
Assuntos
Proteína GAP-43/metabolismo , Macrófagos/imunologia , Neutrófilos/imunologia , Receptores de Superfície Celular/metabolismo , Nervo Isquiático/imunologia , Neuropatia Ciática/imunologia , Receptor 4 Toll-Like/genética , Animais , Caspase 1/genética , Caspase 1/metabolismo , Movimento Celular , Citocinas/genética , Citocinas/metabolismo , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Camundongos Mutantes , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptores de Superfície Celular/genética , Receptores de Fator de Crescimento Neural/metabolismo , Recuperação de Função FisiológicaRESUMO
Interleukin-8 (IL-8) is a pro-inflammatory cytokine that has been shown to play a role in inflammatory and autoimmune disorders. The objective of the present study was to assess the levels of IL-8 in rat serum, dorsal root ganglion (DRG) and the sciatic nerve following four different forms of sciatic nerve injury. The models used to induce the injury included partial sciatic ligation (PSL), chronic constriction injury (CCI), perineural inflammation (neuritis) and complete sciatic transection (CST). Mechanical and thermal hyperalgesia were detected by measuring withdrawal responses from a mechanical stimulus and withdrawal latency from thermal stimulation. Enzyme-linked immunosorbent assays (ELISA) was used to assess the IL-8 levels in the affected and contralateral sciatic nerves. Rats exposed to PSL and neuritis developed significant nociceptive response (mechanical and thermal hyperalgesia) in the affected side at three days post-surgery whereas the CCI group at eight days post-surgery. No mechanical or thermal hyperalgesia was observed in rats exposed to CST at either three or eight days postsurgery. Additionally, IL-8 levels were significantly increased in the injured sciatic nerve at 3 and 8days following PSL and neuritis as well as at 8days following CCI when compared to naïve animals. A significant up regulation of IL-8 levels was observed in the ipsilateral DRG at 3 and 8days following CST compared to naïve animals. The serum IL-8 levels remained unchanged in all models of nerve damage. The results of this study suggest that IL-8's role in the neuropathic pain etiology may be specific to nerve injury type.
Assuntos
Gânglios Espinais , Interleucina-8/metabolismo , Neuralgia , Nervo Isquiático , Neuropatia Ciática , Animais , Modelos Animais de Doenças , Gânglios Espinais/imunologia , Gânglios Espinais/metabolismo , Gânglios Espinais/fisiopatologia , Interleucina-8/sangue , Masculino , Neuralgia/imunologia , Neuralgia/metabolismo , Neuralgia/fisiopatologia , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/lesões , Nervo Isquiático/metabolismo , Nervo Isquiático/fisiopatologia , Neuropatia Ciática/imunologia , Neuropatia Ciática/metabolismo , Neuropatia Ciática/fisiopatologiaRESUMO
BACKGROUND: Cellular responses to nerve injury play a central role in the pathogenesis of neuropathic pain. However, the analysis of site specific cellular responses to nerve injury and neuropathic pain is limited to immunohistochemistry staining with numerous limitations. NEW METHODS: We proposed to apply flow cytometry to overcome some of the limitations and developed two protocols for isolation of cells from small specimens of the sciatic nerve and dorsal root ganglion (DRG) in mice. RESULTS AND COMPARASION WITH EXISTING: methods We found that both the non-enzymatic and enzymatic approaches were highly effective in harvesting a sufficient number of cells for flow cytometry analysis in normal and pathological conditions. The total number of cells in the injury site of the sciatic and its DRGs increased significantly 14days after chronic constriction injury (CCI) of the sciatic nerve, compared to sham surgery control or the contralateral control. The enzymatic approach yielded a significantly higher total number of cells and CD45 negative cells, suggesting that this approach allows for harvest of more resident cells, compared to the non-enzymatic method. The percentage of CD45+/CD11b+ cells was significantly increased in the sciatic nerve but not in the DRG. These results were consistent with both protocols. CONCLUSIONS: We thus offer two simple and effective protocols that allow for application of flow cytometry to the investigation of cellular and molecular mechanisms of neuropathic pain.
Assuntos
Citometria de Fluxo/métodos , Síndromes de Compressão Nervosa/imunologia , Síndromes de Compressão Nervosa/patologia , Neuralgia/imunologia , Neuralgia/patologia , Neuropatia Ciática/imunologia , Neuropatia Ciática/patologia , Animais , Feminino , Gânglios Espinais/imunologia , Gânglios Espinais/lesões , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nervo Isquiático/imunologia , Nervo Isquiático/patologiaRESUMO
The precise mechanisms underlying the efficacy of intravenous immunoglobulin (IVIg) in autoimmune neurological disorders including Guillain-Barré syndrome (GBS) are not known. Anti-ganglioside antibodies have been reported to be pathogenic in some variants of GBS, and we have developed passive transfer animal models to study anti-ganglioside antibody mediated-endoneurial inflammation and associated neuropathological effects and to evaluate the efficacy of new therapeutic approaches. Some studies indicate that IVIg's anti-inflammatory activity resides in a minor sialylated IVIg (sIVIg) fractions and is dependent on an innate Th2 response via binding to a specific ICAM3-grabbing nonintegrin related 1 receptor (SIGN-R1). Therefore the efficacy of IVIg, IVIg fractions with various IgG Fc sialylation status, and the involvement of Th2 pathway were examined in one of our animal model of antibody-mediated inhibition of axonal regeneration. We demonstrate that both IVIg and sIVIg ameliorated anti-glycan antibody mediated-pathological effect, whereas, the unsialylated fractions of IVIg were not beneficial in our model. Tenfold lower doses of sIVIg compared to whole IVIg provided equivalent efficacy in our studies. Moreover, we found that whole IVIg and sIVIg significantly upregulates the gene expression of IL-33, which itself can provide protection from antibody-mediated nerve injury in our model. Our results support that the SIGN-R1-Th2 pathway is involved in the anti-inflammatory effects of IVIg on endoneurium in our model and elements of this pathway including IL-33 can provide novel therapeutics in inflammatory neuropathies.
Assuntos
Anticorpos/metabolismo , Gangliosídeos/imunologia , Síndrome de Guillain-Barré/tratamento farmacológico , Imunoglobulinas Intravenosas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Neuropatia Ciática/tratamento farmacológico , Neuropatia Ciática/metabolismo , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Gangliosídeos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Síndrome de Guillain-Barré/imunologia , Síndrome de Guillain-Barré/metabolismo , Interleucina-33/genética , Interleucina-33/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Regeneração Nervosa/efeitos dos fármacos , RNA Mensageiro/metabolismo , Recuperação de Função Fisiológica/efeitos dos fármacos , Neuropatia Ciática/imunologia , Fatores de TempoRESUMO
Prior studies of aging and neuropathic injury have focused on senescent animals compared to young adults, while changes in middle age, particularly in the dorsal root ganglia (DRG), have remained largely unexplored. 14 neuroimmune mRNA markers, previously associated with peripheral nerve injury, were measured in multiplex assays of lumbar spinal cord (LSC), and DRG from young and middle-aged (3, 17 month) naïve rats, or from rats subjected to chronic constriction injury (CCI) of the sciatic nerve (after 7 days), or from aged-matched sham controls. Results showed that CD2, CD3e, CD68, CD45, TNF-α, IL6, CCL2, ATF3 and TGFß1 mRNA levels were substantially elevated in LSC from naïve middle-aged animals compared to young adults. Similarly, LSC samples from older sham animals showed increased levels of T-cell and microglial/macrophage markers. CCI induced further increases in CCL2, and IL6, and elevated ATF3 mRNA levels in LSC of young and middle-aged adults. Immunofluorescence images of dorsal horn microglia from middle-aged naïve or sham rats were typically hypertrophic with mostly thickened, de-ramified processes, similar to microglia following CCI. Unlike the spinal cord, marker expression profiles in naïve DRG were unchanged across age (except increased ATF3); whereas, levels of GFAP protein, localized to satellite glia, were highly elevated in middle age, but independent of nerve injury. Most neuroimmune markers were elevated in DRG following CCI in young adults, yet middle-aged animals showed little response to injury. No age-related changes in nociception (heat, cold, mechanical) were observed in naïve adults, or at days 3 or 7 post-CCI. The patterns of marker expression and microglial morphologies in healthy middle age are consistent with development of a para-inflammatory state involving microglial activation and T-cell marker elevation in the dorsal horn, and neuronal stress and satellite cell activation in the DRG. These changes, however, did not affect the establishment of neuropathic pain.
Assuntos
Envelhecimento/metabolismo , Gânglios Espinais/metabolismo , Neuralgia/metabolismo , Nociceptividade/fisiologia , Neuropatia Ciática/metabolismo , Medula Espinal/metabolismo , Fatores Etários , Envelhecimento/imunologia , Animais , Antígenos CD/metabolismo , Citocinas/metabolismo , Gânglios Espinais/imunologia , Masculino , Microglia/imunologia , Microglia/metabolismo , Neuralgia/imunologia , Ratos , Células Satélites Perineuronais/imunologia , Células Satélites Perineuronais/metabolismo , Neuropatia Ciática/imunologia , Medula Espinal/imunologiaRESUMO
Neuronal activity regulated pentraxin (Narp) is a secreted protein implicated in regulating synaptic plasticity via its association with the extracellular surface of AMPA receptors. We found robust Narp immunostaining in dorsal root ganglia (DRG) that is largely restricted to small diameter neurons, and in the superficial layers of the dorsal horn of the spinal cord. In double staining studies of DRG, we found that Narp is expressed in both IB4- and CGRP-positive neurons, markers of distinct populations of nociceptive neurons. Although a panel of standard pain behavioral assays were unaffected by Narp deletion, we found that Narp knockout mice displayed an exaggerated microglia/macrophage response in the dorsal horn of the spinal cord to sciatic nerve transection 3days after surgery compared with wild type mice. As other members of the pentraxin family have been implicated in regulating innate immunity, these findings suggest that Narp, and perhaps other neuronal pentraxins, also regulate inflammation in the nervous system.
Assuntos
Proteína C-Reativa/imunologia , Macrófagos/imunologia , Microglia/imunologia , Proteínas do Tecido Nervoso/imunologia , Nociceptores/imunologia , Células Receptoras Sensoriais/imunologia , Neuropatia Tibial/imunologia , Animais , Proteína C-Reativa/genética , Feminino , Gânglios Espinais/citologia , Gânglios Espinais/imunologia , Expressão Gênica/imunologia , Hiperalgesia/imunologia , Macrófagos/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/citologia , Proteínas do Tecido Nervoso/genética , Células do Corno Posterior/citologia , Células do Corno Posterior/imunologia , Ratos , Ratos Sprague-Dawley , Rizotomia , Neuropatia Ciática/imunologia , Neuropatia Ciática/patologia , Células Receptoras Sensoriais/citologia , Nervo Tibial/imunologia , Nervo Tibial/lesões , Neuropatia Tibial/patologiaRESUMO
The widespread plant volatile beta-caryophyllene (BCP) was recently identified as a natural selective agonist of the peripherally expressed cannabinoid receptor 2 (CB2). It is found in relatively high concentrations in many spices and food plants. A number of studies have shown that CB2 is critically involved in the modulation of inflammatory and neuropathic pain responses. In this study, we have investigated the analgesic effects of BCP in animal models of inflammatory and neuropathic pain. We demonstrate that orally administered BCP reduced inflammatory (late phase) pain responses in the formalin test in a CB2 receptor-dependent manner, while it had no effect on acute (early phase) responses. In a neuropathic pain model the chronic oral administration of BCP attenuated thermal hyperalgesia and mechanical allodynia, and reduced spinal neuroinflammation. Importantly, we found no signs of tolerance to the anti-hyperalgesic effects of BCP after prolonged treatment. Oral BCP was more effective than the subcutaneously injected synthetic CB2 agonist JWH-133. Thus, the natural plant product BCP may be highly effective in the treatment of long lasting, debilitating pain states. Our results have important implications for the role of dietary factors in the development and modulation of chronic pain conditions.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Agonistas de Receptores de Canabinoides/uso terapêutico , Modelos Animais de Doenças , Neuralgia/tratamento farmacológico , Receptor CB2 de Canabinoide/agonistas , Neuropatia Ciática/tratamento farmacológico , Sesquiterpenos/uso terapêutico , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/efeitos adversos , Comportamento Animal/efeitos dos fármacos , Agonistas de Receptores de Canabinoides/administração & dosagem , Agonistas de Receptores de Canabinoides/efeitos adversos , Regulação da Expressão Gênica/efeitos dos fármacos , Hiperalgesia/tratamento farmacológico , Hiperalgesia/imunologia , Hiperalgesia/metabolismo , Masculino , Camundongos , Camundongos Congênicos , Atividade Motora/efeitos dos fármacos , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuralgia/imunologia , Neuralgia/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/imunologia , Neurônios/metabolismo , Medição da Dor , Compostos Fitoquímicos/administração & dosagem , Compostos Fitoquímicos/efeitos adversos , Compostos Fitoquímicos/uso terapêutico , Sesquiterpenos Policíclicos , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/metabolismo , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/imunologia , Nervo Isquiático/metabolismo , Neuropatia Ciática/imunologia , Neuropatia Ciática/metabolismo , Sesquiterpenos/administração & dosagem , Sesquiterpenos/efeitos adversos , Medula Espinal/efeitos dos fármacos , Medula Espinal/imunologia , Medula Espinal/metabolismoRESUMO
Subsequent to peripheral nerve compression and irritation, pathophysiological processes take place within nervous and immune systems. Here, we utilized a multimodal approach to comprehend peripheral and central soft tissue changes as well as alterations occurring in systemic analytes following unilateral chronic constriction injury (CCI) of the sciatic nerve in rodents. Using magnetic resonance imaging and [18F]-2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography, we demonstrated robust structural abnormalities and enhanced FDG uptake within the injured nerve and surrounding muscle, respectively. To assess whether central morphological changes were induced by nerve injury, diffusion tenor imaging was performed. A decrease in fractional anisotropy in primary motor cortex contralateral to the injury site was observed. Evaluation of a panel of circulating cytokines, chemokines, and growth factors showed decreased levels of interleukin-1ß and Fractalkine in CCI animals. Area under the receiver operating curve (ROC) calculations of analyte levels, imaging, and behavioral end points ranged from 0.786 to 1, where behavioral and peripheral imaging end points (eg, FDG uptake in muscle) were observed to have the highest discriminatory capabilities (maximum area under ROC = 1) between nerve injury and sham conditions. Lastly, performance of correlation analysis involving all analyte, behavioral, and imaging data provided an understanding of the overall association amongst these end points, and importantly, a distinction in correlation patterns was observed between CCI and sham conditions. These findings demonstrate the multidimensional pathophysiology of sciatic nerve injury and how a combined analyte, behavioral, and imaging assessment can be implemented to probe this complexity.
Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Mediadores da Inflamação/sangue , Neuropatia Ciática/sangue , Neuropatia Ciática/diagnóstico , Animais , Biomarcadores/sangue , Polarização de Fluorescência/métodos , Mediadores da Inflamação/imunologia , Imageamento por Ressonância Magnética/métodos , Masculino , Tomografia por Emissão de Pósitrons/métodos , Ratos , Ratos Sprague-Dawley , Neuropatia Ciática/imunologiaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: The infusion or decoction of Mirabilis jalapa leaves is used in traditional medicine in Brazil to treat inflammatory and painful diseases. Thus, the present study was designed to investigate whether the leaf ethyl acetate (Eta) fraction from Mirabilis jalapa exhibits antinociceptive effect in clinically relevant pain models in mice. Furthermore, we have investigated the role of cholinergic system in the antinociceptive action produced by Eta in mice. MATERIALS AND METHODS: The effect of Eta administered orally (10mg/kg, p.o.) in mice was verified on the painful hypersensitivity (mechanical allodynia) in models of chronic inflammation (subcutaneous injection of complete Freund's Adjuvant-CFA in the plantar surface of the right hind paw), postoperative (paw surgical incision) and neuropathic (partial sciatic nerve ligation) pain. In the chronic inflammation model, we further verified the effect of Eta treatment on paw edema and interleukin-1ß (IL-1ß) levels. We also investigated the role of muscarinic and nicotinic receptors in the antiallodynic action produced by Eta as well as the possible action of Eta on in vitro and ex vivo acetylcholinesterase activity in CFA treated animals. Furthermore, we verified the effect of Eta treatment on the parameters of liver and kidney lesion (level of urea, and activity of aspartate aminotransferase and alanine aminotransferase). RESULTS: Eta produced marked reduction in the allodynia caused by CFA, surgical incision and partial sciatic nerve ligation. However, Eta did not alter the paw edema or the increase of IL-1ß levels produced by CFA. The antinociceptive effect of Eta was reversed by the pre-treatment of animals with the antagonists of muscarinic (atropine, 5mg/kg, s.c) or nicotinic (mecamylamine, 0.001mg/kg, s.c.) receptors. Eta did not alter in vitro acetylcholinesterase activity in blood or spinal cord samples, but it reversed the increase in the acetylcholinesterase activity observed in the spinal cord samples from mice injected with CFA. Moreover, Eta did not alter the indicators of liver or kidney lesion. CONCLUSIONS: Based on its use in traditional medicine, the results of the present study confirmed the antinociceptive properties of Eta in clinically relevant pain models. Also its effect on the CFA-induced chronic inflammation seems to be related to acetylcholinesterase inhibition and cholinergic system.
Assuntos
Dor Aguda/tratamento farmacológico , Analgésicos/uso terapêutico , Dor Crônica/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Acetilcolinesterase/metabolismo , Dor Aguda/enzimologia , Dor Aguda/imunologia , Analgésicos/isolamento & purificação , Analgésicos/toxicidade , Animais , Artrite Experimental/tratamento farmacológico , Artrite Experimental/enzimologia , Artrite Experimental/imunologia , Dor Crônica/enzimologia , Dor Crônica/imunologia , Hiperalgesia/tratamento farmacológico , Hiperalgesia/enzimologia , Hiperalgesia/imunologia , Interleucina-1beta/imunologia , Masculino , Camundongos , Medição da Dor , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/enzimologia , Dor Pós-Operatória/imunologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Folhas de Planta/química , Neuropatia Ciática/tratamento farmacológico , Neuropatia Ciática/enzimologia , Neuropatia Ciática/imunologiaRESUMO
Peripheral neuropathy and insensate limbs and digits cause significant morbidity in diabetic individuals. Previous studies showed that deletion of the receptor for advanced end-glycation products (RAGE) in mice was protective in long-term diabetic neuropathy. Here, we tested the hypothesis that RAGE suppresses effective axonal regeneration in superimposed acute peripheral nerve injury attributable to tissue-damaging inflammatory responses. We report that deletion of RAGE, particularly in diabetic mice, resulted in significantly higher myelinated fiber densities and conduction velocities consequent to acute sciatic nerve crush compared with wild-type control animals. Consistent with key roles for RAGE-dependent inflammation, reconstitution of diabetic wild-type mice with RAGE-null versus wild-type bone marrow resulted in significantly improved axonal regeneration and restoration of function. Diabetic RAGE-null mice displayed higher numbers of invading macrophages in the nerve segments postcrush compared with wild-type animals, and these macrophages in diabetic RAGE-null mice displayed greater M2 polarization. In vitro, treatment of wild-type bone marrow-derived macrophages with advanced glycation end products (AGEs), which accumulate in diabetic nerve tissue, increased M1 and decreased M2 gene expression in a RAGE-dependent manner. Blockade of RAGE may be beneficial in the acute complications of diabetic neuropathy, at least in part, via upregulation of regeneration signals.