RESUMO
We have previously reported evidence that Nogo-A activation of Nogo-receptor 1 (NgR1) can drive axonal dystrophy during the neurological progression of experimental autoimmune encephalomyelitis (EAE). However, the B-cell activating factor (BAFF/BlyS) may also be an important ligand of NgR during neuroinflammation. In the current study we define that NgR1 and its homologs may contribute to immune cell signaling during EAE. Meningeal B-cells expressing NgR1 and NgR3 were identified within the lumbosacral spinal cords of ngr1+/+ EAE-induced mice at clinical score 1. Furthermore, increased secretion of immunoglobulins that bound to central nervous system myelin were shown to be generated from isolated NgR1- and NgR3-expressing B-cells of ngr1+/+ EAE-induced mice. In vitro BAFF stimulation of NgR1- and NgR3-expressing B cells, directed them into the cell cycle DNA synthesis phase. However, when we antagonized BAFF signaling by co-incubation with recombinant BAFF-R, NgR1-Fc, or NgR3 peptides, the B cells remained in the G0/G1 phase. The data suggest that B cells express NgR1 and NgR3 during EAE, being localized to infiltrates of the meninges and that their regulation is governed by BAFF signaling.
Assuntos
Fator Ativador de Células B/metabolismo , Linfócitos B/imunologia , Encefalomielite Autoimune Experimental/imunologia , Meninges/patologia , Esclerose Múltipla/imunologia , Animais , Linfócitos B/metabolismo , Encefalomielite Autoimune Experimental/patologia , Feminino , Humanos , Meninges/imunologia , Camundongos , Camundongos Knockout , Esclerose Múltipla/patologia , Proteínas Nogo/metabolismo , Receptor Nogo 1/genética , Receptor Nogo 1/metabolismo , Receptores Nogo/metabolismoRESUMO
OBJECTIVE: The purpose of this case report is to describe chiropractic management of an elderly man with untreated bilateral hip joint dysplasia presenting with mild acute mechanical low back pain. CLINICAL FEATURES: A 75-year-old man presented with an insidious-onset intermittent low back pain of 3 days' duration. Physical examination findings supported a mechanical cause for mild acute low back pain. Plain radiography revealed dysplasia of hip joints with absence of femoral heads and necks and bilateral high dislocation. INTERVENTION AND OUTCOME: Chiropractic management included vibration, mobilization, light drop-piece adjustments of the lower lumbar and sacroiliac joints, and recommendation of the use of heat at home. Treatments were given 3 times over the course of 1 week. The low back pain intensity over this period dropped from 5 to 0 on an 11-point numerical rating scale, and the patient was discharged. CONCLUSION: This patient with substantial postural and gait abnormalities as a result of severe bilateral hip dysplasia associated with an unusual pattern of osteoarthritic change in the spine responded favorably to a short course of chiropractic care.
RESUMO
Multiple sclerosis involves demyelination and axonal degeneration of the central nervous system. The molecular mechanisms of axonal degeneration are relatively unexplored in both multiple sclerosis and its mouse model, experimental autoimmune encephalomyelitis. We previously reported that targeting the axonal growth inhibitor, Nogo-A, may protect against neurodegeneration in experimental autoimmune encephalomyelitis; however, the mechanism by which this occurs is unclear. We now show that the collapsin response mediator protein 2 (CRMP-2), an important tubulin-associated protein that regulates axonal growth, is phosphorylated and hence inhibited during the progression of experimental autoimmune encephalomyelitis in degenerating axons. The phosphorylated form of CRMP-2 (pThr555CRMP-2) is localized to spinal cord neurons and axons in chronic-active multiple sclerosis lesions. Specifically, pThr555CRMP-2 is implicated to be Nogo-66 receptor 1 (NgR1)-dependent, since myelin oligodendrocyte glycoprotein (MOG)(35-55)-induced NgR1 knock-out (ngr1(-)(/)(-)) mice display a reduced experimental autoimmune encephalomyelitis disease progression, without a deregulation of ngr1(-)(/)(-) MOG(35-55)-reactive lymphocytes and monocytes. The limitation of axonal degeneration/loss in experimental autoimmune encephalomyelitis-induced ngr1(-)(/)(-) mice is associated with lower levels of pThr555CRMP-2 in the spinal cord and optic nerve during experimental autoimmune encephalomyelitis. Furthermore, transduction of retinal ganglion cells with an adeno-associated viral vector encoding a site-specific mutant T555ACRMP-2 construct, limits optic nerve axonal degeneration occurring at peak stage of experimental autoimmune encephalomyelitis. Therapeutic administration of the anti-Nogo(623-640) antibody during the course of experimental autoimmune encephalomyelitis, associated with an improved clinical outcome, is demonstrated to abrogate the protein levels of pThr555CRMP-2 in the spinal cord and improve pathological outcome. We conclude that phosphorylation of CRMP-2 may be downstream of NgR1 activation and play a role in axonal degeneration in experimental autoimmune encephalomyelitis and multiple sclerosis. Blockade of Nogo-A/NgR1 interaction may serve as a viable therapeutic target in multiple sclerosis.
Assuntos
Axônios/metabolismo , Encefalomielite Autoimune Experimental/complicações , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Esclerose Múltipla/patologia , Degeneração Neural/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Adulto , Análise de Variância , Animais , Anticorpos/uso terapêutico , Axônios/patologia , Axônios/ultraestrutura , Complexo CD3/metabolismo , Linhagem Celular Tumoral , Doenças Desmielinizantes/etiologia , Doenças Desmielinizantes/metabolismo , Doenças Desmielinizantes/patologia , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/imunologia , Feminino , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/deficiência , Proteínas Ligadas por GPI/imunologia , Regulação da Expressão Gênica/genética , Glicoproteínas/efeitos adversos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Esclerose Múltipla/complicações , Mutação/genética , Proteínas da Mielina/antagonistas & inibidores , Proteínas da Mielina/deficiência , Proteínas da Mielina/imunologia , Glicoproteína Mielina-Oligodendrócito , Degeneração Neural/etiologia , Proteínas do Tecido Nervoso/genética , Neuroblastoma/patologia , Proteínas de Neurofilamentos/metabolismo , Receptor Nogo 1 , Nervo Óptico/metabolismo , Nervo Óptico/patologia , Fragmentos de Peptídeos/efeitos adversos , Fosforilação , Receptores de Superfície Celular/antagonistas & inibidores , Receptores de Superfície Celular/deficiência , Receptores de Superfície Celular/imunologia , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/patologiaRESUMO
Accumulation of the amyloid protein (Abeta) in the brain is an important step in the pathogenesis of Alzheimer's disease. However, the mechanism by which Abeta exerts its neurotoxic effect is largely unknown. It has been suggested that the peptide can bind to the alpha7 nicotinic acetylcholine receptor (alpha7nAChR). In this study, we examined the binding of Abeta1-42 to endogenous and recombinantly expressed alpha7nAChRs. Abeta1-42 did neither inhibit the specific binding of alpha7nAChR ligands to rat brain homogenate or slice preparations, nor did it influence the activity of alpha7nAChRs expressed in Xenopus oocytes. Similarly, Abeta1-42 did not compete for alpha-bungarotoxin-binding sites on SH-SY5Y cells stably expressing alpha7nAChRs. The effect of the Abeta1-42 on tau phosphorylation was also examined. Although Abeta1-42 altered tau phosphorylation in alpha7nAChR-transfected SH-SY5Y cells, the effect of the peptide was unrelated to alpha7nAChR expression or activity. Binding studies using surface plasmon resonance indicated that the majority of the Abeta bound to membrane lipid, rather than to a protein component. Fluorescence anisotropy experiments indicated that Abeta may disrupt membrane lipid structure or fluidity. We conclude that the effects of Abeta are unlikely to be mediated by direct binding to the alpha7nAChR. Instead, we speculate that Abeta may exert its effects by altering the packing of lipids within the plasma membrane, which could, in turn, influence the function of a variety of receptors and channels on the cell surface.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Lipídeos de Membrana/metabolismo , Receptores Nicotínicos/metabolismo , Aconitina/análogos & derivados , Aconitina/metabolismo , Animais , Bungarotoxinas/metabolismo , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Feminino , Polarização de Fluorescência , Hipocampo/metabolismo , Humanos , Fluidez de Membrana/efeitos dos fármacos , Neuroblastoma/metabolismo , Oócitos/metabolismo , Ratos , Ratos Sprague-Dawley , Ressonância de Plasmônio de Superfície , Transfecção , Xenopus laevis , Receptor Nicotínico de Acetilcolina alfa7 , Proteínas tau/metabolismoRESUMO
As a consequence of secondary pathophysiological mechanisms elicited after spinal cord injury (SCI), oligodendrocytes die by waves of apoptosis. This ultimately results in demyelination of intact axons leading to a loss of their conducting properties. Preservation of as few as 5% to 10% of myelinated axons in individual tracts can confer locomotor recovery. Thus, strategies aimed at rescuing mature oligodendrocytes ensheathing viable axons are likely to be of therapeutic significance. We report that leukemia inhibitory factor (LIF) can prevent oligodendrocyte apoptosis, notably contralateral to the spinal cord lesion, through the induction of the JAK/STAT and Akt signaling pathways as well as by potentiating the expression of the antiapoptotic molecule, cIAP2. Reduced oligodendrocyte apoptosis after SCI with LIF administration resulted in a substantial decrease in demyelination shown by the preservation of lamellated myelin surrounding viable axons and deposition of the degraded myelin basic protein. The data suggest that LIF signals survival in oligodendrocytes after SCI, prevents the secondary wave of demyelination, and thereby reduces inhibitory myelin deposits.
Assuntos
Doenças Desmielinizantes/tratamento farmacológico , Interleucina-6/administração & dosagem , Oligodendroglia/efeitos dos fármacos , Traumatismos da Medula Espinal , Animais , Axotomia/métodos , Proteína 3 com Repetições IAP de Baculovírus , Morte Celular/efeitos dos fármacos , Doenças Desmielinizantes/etiologia , Modelos Animais de Doenças , Feminino , Expressão Gênica/efeitos dos fármacos , Imunoprecipitação/métodos , Marcação In Situ das Extremidades Cortadas/métodos , Proteínas Inibidoras de Apoptose/metabolismo , Fator Inibidor de Leucemia , Subunidade alfa de Receptor de Fator Inibidor de Leucemia , Camundongos , Camundongos Endogâmicos C57BL , Proteína Básica da Mielina/metabolismo , Oligodendroglia/fisiologia , Receptores de Citocinas/metabolismo , Receptores de OSM-LIF , Fatores de Transcrição STAT/metabolismo , Índice de Gravidade de Doença , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia , Ubiquitina-Proteína LigasesRESUMO
Administration of tumour necrosis factor alpha (TNFalpha) to axotomised mouse neonatal sciatic nerves increased Schwann cell apoptosis in the distal nerve segments, 5-fold greater than axotomy alone. TNFalpha upregulated the low affinity neurotrophin receptor, p75NTR, indicative of phenotype reversion in Schwann cells. Furthermore, re-expression of p75NTR and downregulation of the pro-myelinating transcription factor, Oct 6, in Schwann cells occurred by treatment with TNFalpha, even after the maturation of these cells with brain derived neurotrophic factor (BDNF). TNFalpha treatment of Schwann cells produced only a transient activation of NFkappaB. More importantly, in NFkappaB (p65) mutant mice, axotomy increased Schwann cell apoptosis further than that seen in mice expressing NFkappaB (p65), implicating a survival role for NFkappaB. Collectively, these data suggest that TNFalpha can potentiate Schwann cell death through the modulation of their phenotype. Immature Schwann cells express a high level of p75NTR and as a consequence are susceptible to extracellular death stimuli because of the lack of sustained NFkappaB translocation.
Assuntos
NF-kappa B/metabolismo , Nervos Periféricos/metabolismo , Receptor de Fator de Crescimento Neural/metabolismo , Células de Schwann/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Animais Recém-Nascidos , Axotomia , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/efeitos dos fármacos , Fator 6 de Transcrição de Octâmero/efeitos dos fármacos , Fator 6 de Transcrição de Octâmero/metabolismo , Nervos Periféricos/efeitos dos fármacos , Nervos Periféricos/fisiopatologia , Doenças do Sistema Nervoso Periférico/metabolismo , Doenças do Sistema Nervoso Periférico/fisiopatologia , Fenótipo , Polirradiculoneuropatia/metabolismo , Polirradiculoneuropatia/fisiopatologia , Ratos , Ratos Wistar , Células de Schwann/efeitos dos fármacos , Células de Schwann/patologia , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/metabolismo , Nervo Isquiático/fisiopatologia , Fator de Transcrição RelA/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologiaRESUMO
We investigated the anatomical and behavioural effects of daily intraperitoneal injection of 25 microg/kg of LIF in the SOD1(G93A G1H) mouse model of familial ALS. We found some subtle beneficial behavioural changes in LIF treated mice. These included later onset of clinical disease in females as determined by clinical scoring; better grip strength in males; and delayed development of motor impairment in males as determined by the rotarod test. However, we found no significant rescue of motoneurons or prolongation of survival as a result of this systemic dose of LIF in these mice.