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1.
Proc Natl Acad Sci U S A ; 117(3): 1762-1771, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31900358

RESUMO

The pathological hallmark of synucleinopathies, including Lewy body dementia and Parkinson's disease (PD), is the presence of Lewy bodies, which are primarily composed of intracellular inclusions of misfolded α-synuclein (α-syn) among other proteins. α-Syn is found in extracellular biological fluids in PD patients and has been implicated in modulating immune responses in the central nervous system (CNS) and the periphery. Natural killer (NK) cells are innate effector lymphocytes that are present in the CNS in homeostatic and pathological conditions. NK cell numbers are increased in the blood of PD patients and their activity is associated with disease severity; however, the role of NK cells in the context of α-synucleinopathies has never been explored. Here, we show that human NK cells can efficiently internalize and degrade α-syn aggregates via the endosomal/lysosomal pathway. We demonstrate that α-syn aggregates attenuate NK cell cytotoxicity in a dose-dependent manner and decrease the release of the proinflammatory cytokine, IFN-γ. To address the role of NK cells in PD pathogenesis, NK cell function was investigated in a preformed fibril α-syn-induced mouse PD model. Our studies demonstrate that in vivo depletion of NK cells in a preclinical mouse PD model resulted in exacerbated motor deficits and increased phosphorylated α-syn deposits. Collectively, our data provide a role of NK cells in modulating synuclein pathology and motor symptoms in a preclinical mouse model of PD, which could be developed into a therapeutic for PD and other synucleinopathies.


Assuntos
Células Matadoras Naturais/metabolismo , Sinucleinopatias/metabolismo , Sinucleínas/metabolismo , alfa-Sinucleína/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Sistema Nervoso Central/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Corpos de Lewy/metabolismo , Doença por Corpos de Lewy/metabolismo , Lisossomos/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Doença de Parkinson/metabolismo , Sinucleinopatias/genética , Sinucleinopatias/patologia
2.
Molecules ; 27(5)2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35268801

RESUMO

Majority of dynamic nuclear polarization (DNP) experiments have been requiring helium cryogenics and strong magnetic fields for a high degree of nuclear polarization. In this work, we instead demonstrate an optical hyperpolarization of naturally abundant 13C nuclei in a diamond crystal at a low magnetic field and the room temperature. It exploits continuous laser irradiation for polarizing electronic spins of nitrogen vacancy centers and microwave irradiation for transferring the electronic polarization to 13C nuclear spins. We have studied the dependence of 13C polarization on laser and microwave powers. For the first time, a triplet structure corresponding to the 14N hyperfine splitting has been observed in the 13C polarization spectrum. By simultaneously exciting three microwave frequencies at the peaks of the triplet, we have achieved 13C bulk polarization of 0.113 %, leading to an enhancement of 90,000 over the thermal polarization at 17.6 mT. We believe that the multi-tone irradiation can be extended to further enhance the 13C polarization at a low magnetic field.

3.
J Neurophysiol ; 122(2): 616-631, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31166824

RESUMO

The cutaneus trunci muscle (CTM) reflex produces a skin "shrug" in response to pinch on a rat's back through a three-part neural circuit: 1) A-fiber and C-fiber afferents in segmental dorsal cutaneous nerves (DCNs) from lumbar to cervical levels, 2) ascending propriospinal interneurons, and 3) the CTM motoneuron pool located at the cervicothoracic junction. We recorded neurograms from a CTM nerve branch in response to electrical stimulation. The pulse trains were delivered at multiple DCNs (T6-L1), on both sides of the midline, at two stimulus strengths (0.5 or 5 mA, to activate Aδ fibers or Aδ and C fibers, respectively) and four stimulation frequencies (1, 2, 5, or 10 Hz) for 20 s. We quantified both the temporal dynamics (i.e., latency, sensitization, habituation, and frequency dependence) and the spatial dynamics (spinal level) of the reflex. The evoked responses were time-windowed into Early, Mid, Late, and Ongoing phases, of which the Mid phase, between the Early (Aδ fiber mediated) and Late (C fiber mediated) phases, has not been previously identified. All phases of the response varied with stimulus strength, frequency, history, and DCN level/side stimulated. In addition, we observed nociceptive characteristics like C fiber-mediated sensitization (wind-up) and habituation. Finally, the range of latencies in the ipsilateral responses were not very large rostrocaudally, suggesting a myelinated neural path within the ipsilateral spinal cord for at least the A fiber-mediated Early-phase response. Overall, these results demonstrate that the CTM reflex shares the temporal dynamics in other nociceptive reflexes and exhibits spatial (segmental and lateral) dynamics not seen in those reflexes.NEW & NOTEWORTHY We have physiologically studied an intersegmental reflex exploring detailed temporal, stimulus strength-based, stimulation history-dependent, lateral and segmental quantification of the reflex responses to cutaneous nociceptive stimulations. We found several physiological features in this reflex pathway, e.g., wind-up, latency changes, and somatotopic differences. These physiological observations allow us to understand how the anatomy of this reflex may be organized. We have also identified a new phase of this reflex, termed the "mid" response.


Assuntos
Músculos do Dorso/fisiologia , Potenciais Evocados/fisiologia , Habituação Psicofisiológica/fisiologia , Fibras Nervosas Mielinizadas/fisiologia , Fibras Nervosas Amielínicas/fisiologia , Nociceptividade/fisiologia , Reflexo/fisiologia , Medula Espinal/fisiologia , Animais , Estimulação Elétrica , Feminino , Ratos , Ratos Long-Evans
4.
Neural Plast ; 2019: 6147878, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827498

RESUMO

Electrical stimulations of dorsal cutaneous nerves (DCNs) at each lumbothoracic spinal level produce the bilateral cutaneus trunci muscle (CTM) reflex responses which consist of two temporal components: an early and late responses purportedly mediated by Aδ and C fibers, respectively. We have previously reported central projections of DCN A and C fibers and demonstrated that different projection patterns of those afferent types contributed to the somatotopic organization of CTM reflex responses. Unilateral hemisection spinal cord injury (SCI) was made at T10 spinal segments to investigate the plasticity of early and late CTM responses 6 weeks after injury. Both early and late responses were drastically increased in response to both ipsi- and contralateral DCN stimulations both above (T6 and T8) and below (T12 and L1) the levels of injury demonstrating that nociceptive hyperreflexia developed at 6 weeks following hemisection SCI. We also found that DCN A and C fibers centrally sprouted, expanded their projection areas, and increased synaptic terminations in both T7 and T13, which correlated with the size of hemisection injury. These data demonstrate that central sprouting of cutaneous afferents away from the site of injury is closely associated with enhanced responses of intraspinal signal processing potentially contributing to nociceptive hyperreflexia following SCI.


Assuntos
Músculo Esquelético/fisiopatologia , Reflexo Anormal/fisiologia , Reflexo/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Animais , Estimulação Elétrica/métodos , Feminino , Ratos Long-Evans , Pele/fisiopatologia , Medula Espinal/fisiopatologia
5.
Hum Brain Mapp ; 39(5): 1972-1981, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29363226

RESUMO

Thermoreception is an important cutaneous sense, which plays a role in the maintenance of our body temperature and in the detection of potential noxious heat stimulation. In this study, we investigated event-related fields (ERFs) and neural oscillatory activities, which were modulated by warmth stimulation. We developed a warmth stimulator that could elicit a warmth sensation, without pain or tactile sensation, by using a deep-penetrating 980-nm diode laser. The index finger of each participant (n = 24) was irradiated with the laser warmth stimulus, and the cortical responses were measured using magnetoencephalography (MEG). The ERFs and oscillatory responses had late latencies (∼1.3 s and 1.0-1.5 s for ERFs and oscillatory responses, respectively), which could be explained by a slow conduction velocity of warmth-specific C-fibers. Cortical sources of warmth-related ERFs were seen in the bilateral primary and secondary somatosensory cortices (SI and SII), posterior part of the anterior cingulate cortex (pACC), ipsilateral primary motor, and premotor cortex. Thus, we suggested that SI, SII, and pACC play a role in processing the warmth sensation. Time-frequency analysis demonstrated the suppression of the alpha (8-13 Hz) and beta (18-23 Hz) band power in the bilateral sensorimotor cortex. We proposed that the suppressions in alpha and beta band power are involved in the automatic response to the input of warmth stimulation and sensorimotor interactions. The delta band power (1-4 Hz) increased in the frontal, temporal, and cingulate cortices. The power changes in delta band might be related with the attentional processes during the warmth stimulation.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Potenciais Evocados/fisiologia , Magnetoencefalografia , Pele/inervação , Temperatura , Adulto , Atenção/fisiologia , Eletroencefalografia , Feminino , Humanos , Masculino , Estimulação Física , Adulto Jovem
6.
Int J Mol Sci ; 19(10)2018 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-30262747

RESUMO

In this study, we investigated the effects of minocycline, a putative suppressor of microglial activation, on systemic lipopolysaccharide (LPS)-induced spinal cord inflammation, allodynia, and hyperalgesia in neonatal rats. Intraperitoneal (i.p.) injection of LPS (2 mg/kg) or sterile saline was performed in postnatal day 5 (P5) rat pups and minocycline (45 mg/kg) or vehicle (phosphate buffer saline; PBS) was administered (i.p.) 5 min after LPS injection. The von Frey filament and tail-flick tests were performed to determine mechanical allodynia (a painful sensation caused by innocuous stimuli, e.g., light touch) and thermal hyperalgesia (a condition of altered perception of temperature), respectively, and spinal cord inflammation was examined 24 h after the administration of drugs. Systemic LPS administration resulted in a reduction of tactile threshold in the von Frey filament tests and pain response latency in the tail-flick test of neonatal rats. The levels of microglia and astrocyte activation, pro-inflammatory cytokine interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) in the spinal cord of neonatal rats were increased 24 h after the administration of LPS. Treatment with minocycline significantly attenuated LPS-induced allodynia, hyperalgesia, the increase in spinal cord microglia, and astrocyte activation, and elevated levels of IL-1ß, COX-2, and PGE2 in neonatal rats. These results suggest that minocycline provides protection against neonatal systemic LPS exposure-induced enhanced pain sensitivity (allodynia and hyperalgesia), and that the protective effects may be associated with its ability to attenuate LPS-induced microglia activation, and the levels of IL-1ß, COX-2, and PGE2 in the spinal cord of neonatal rats.


Assuntos
Antibacterianos/uso terapêutico , Hiperalgesia/tratamento farmacológico , Minociclina/uso terapêutico , Animais , Antibacterianos/farmacologia , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Feminino , Hiperalgesia/etiologia , Inflamação , Interleucina-1beta/metabolismo , Lipopolissacarídeos/toxicidade , Masculino , Minociclina/farmacologia , Ratos , Ratos Sprague-Dawley , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Medula Espinal/patologia
7.
Opt Express ; 22(17): 19887-94, 2014 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-25321199

RESUMO

We demonstrate that the use of negative feedback extends the detection bandwidth of an atomic magnetometer in a spin-exchange relaxation free (SERF) regime. A flat-frequency response from zero to 190 Hz was achieved, which is nearly a three-fold enhancement while maintaining sensitivity, 3 fT/Hz1/2 at 100 Hz. With the extension of the bandwidth, the linear correlation between measured signals and a magne-tocardiographic field synthesized for comparison was increased from 0.21 to 0.74. This result supports the feasibility of measuring weak biomagnetic signals containing multiple frequency components using a SERF atomic magnetometer under negative feedback.

8.
Neurobiol Dis ; 56: 104-15, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23639788

RESUMO

Alzheimer's disease (AD) is a devastating neurodegenerative disorder and the most common cause of elderly dementia. In an effort to contribute to the potential of molecular approaches to reduce degenerative processes we have tested the possibility that the neural adhesion molecule L1 ameliorates some characteristic cellular and molecular parameters associated with the disease in a mouse model of AD. Three-month-old mice overexpressing mutated forms of amyloid precursor protein and presenilin-1 under the control of a neuron-specific promoter received an injection of adeno-associated virus encoding the neuronal isoform of full-length L1 (AAV-L1) or, as negative control, green fluorescent protein (AAV-GFP) into the hippocampus and occipital cortex. Four months after virus injection, the mice were analyzed for histological and biochemical parameters of AD. AAV-L1 injection decreased the Aß plaque load, levels of Aß42, Aß42/40 ratio and astrogliosis compared with AAV-GFP controls. AAV-L1 injected mice also had increased densities of inhibitory synaptic terminals on pyramidal cells in the hippocampus when compared with AAV-GFP controls. Numbers of microglial cells/macrophages were similar in both groups, but numbers of microglial cells/macrophages per plaque were increased in AAV-L1 injected mice. To probe for a molecular mechanism that may underlie these effects, we analyzed whether L1 would directly and specifically interact with Aß. In a label-free binding assay, concentration dependent binding of the extracellular domain of L1, but not of the close homolog of L1 to Aß40 and Aß42 was seen, with the fibronectin type III homologous repeats 1-3 of L1 mediating this effect. Aggregation of Aß42 in vitro was reduced in the presence of the extracellular domain of L1. The combined observations indicate that L1, when overexpressed in neurons and glia, reduces several histopathological hallmarks of AD in mice, possibly by reduction of Aß aggregation. L1 thus appears to be a candidate molecule to ameliorate the pathology of AD, when applied in therapeutically viable treatment schemes.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Molécula L1 de Adesão de Célula Nervosa/uso terapêutico , Doença de Alzheimer/patologia , Animais , Western Blotting , Encéfalo/patologia , Dependovirus/genética , Ensaio de Imunoadsorção Enzimática , Gliose/patologia , Proteínas de Fluorescência Verde , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Lobo Occipital/metabolismo , Lobo Occipital/patologia , Placa Amiloide/patologia , Ligação Proteica , Células Piramidais/efeitos dos fármacos , Receptores CCR2/metabolismo , Fixação de Tecidos
9.
J Neurosci Res ; 91(2): 196-210, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23169458

RESUMO

The upregulation of genes normally associated with development may occur in the adult after spinal cord injury (SCI). To test this, we performed real-time RT-PCR array analysis of mouse spinal cord mRNAs comparing embryonic day (E)14.5 spinal cord with intact adult and adult cord 1 week after a clinically relevant standardized contusion SCI. We found significantly increased expression of a large number of neural development- and stem cell-associated genes after SCI. These included Sox2 (sex determining region Y-box 2), a transcription factor that regulates self-renewal and potency of embryonic neural stem cells and is one of only a few key factors needed to induce pluripotency. In adult spinal cord of Sox2-EGFP mice, Sox2-EGFP was found mainly in the ependymal cells of the central canal. After SCI, both mRNA and protein levels of Sox2 were significantly increased at and near the injury site. By 1 day, Sox2 was upregulated in NG2(+) oligodendrocyte progenitor cells (OPC) in the spared white matter. By 3 days, Sox2-EGFP ependymal cells had increased proliferation and begun to form multiple layers and clusters of cells in the central lesion zone of the cord. Expression of Sox2 by NG2(+) cells had declined by 1 week, but increased numbers of other Sox2-expressing cells persisted for at least 4 weeks after SCI in both mouse and rat models. Thus, SCI upregulates many genes associated with development and neural stem cells, including the key transcription factor Sox2, which is expressed in a pool of cells that persists for weeks after SCI.


Assuntos
Epêndima/patologia , Regulação da Expressão Gênica/genética , Oligodendroglia/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Traumatismos da Medula Espinal/patologia , Análise de Variância , Animais , Antígenos/metabolismo , Linhagem da Célula/fisiologia , Proliferação de Células , Modelos Animais de Doenças , Embrião de Mamíferos , Feminino , Citometria de Fluxo , Proteínas de Fluorescência Verde/genética , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Proteoglicanas/metabolismo , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Fatores de Transcrição SOXB1/genética , Traumatismos da Medula Espinal/fisiopatologia , Fatores de Tempo
10.
PLoS One ; 18(4): e0284409, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37058449

RESUMO

To explore the clinical significance of anti-cytosolic 5'-nucleoditase 1A (NT5c1A) antibody seropositivity in inflammatory myopathies, we measured anti-NT5c1A antibodies and analyzed their clinical features. Anti-NT5c1A antibodies were measured in the sera of 103 patients with inflammatory myopathies using an enzyme-linked immunosorbent assay. Positivity for anti-NT5c1A antibody was found in 13 (12.6%) of 103 patients with inflammatory myopathy. Anti-NT5c1A antibody was most frequently identified in patients with inclusion body myositis (IBM) (8/20, 40%), followed by dermatomyositis (2/13, 15.4%), immune-mediated necrotizing myopathy (2/28, 7.1%), and polymyositis (1/42, 2.4%). In eight patients with the anti-NT5c1A antibody-seropositive IBM, the median age at symptom onset was 54 years (interquartile range [IQR]: 48-57 years), and the median disease duration was 34 months (IQR: 24-50 months]. Knee extension weakness was greater than or equal to hip flexion weakness in eight (100%) patients, and finger flexion strength was less than shoulder abduction in three (38%) patients. Dysphagia symptoms were found in three (38%) patients. The median serum CK level was 581 IU/l (IQR: 434-868 IU/L]. Clinically significant differences were not found between anti-NT5c1A antibody-seropositive and seronegative IBM groups with respect to gender, age at symptom onset, age at diagnosis, disease duration, serum CK values, presence of other autoantibodies, dysphagia, and the pattern of muscle impairment. Although anti-NT5c1A antibody is known to be associated with IBM, seropositivity has also been noted in non-IBM inflammatory myopathies, and is insufficient to have clinical significance by itself. These findings have important implications for interpreting anti-NT5c1A antibody test results as the first study in Korea.


Assuntos
Transtornos de Deglutição , Miosite de Corpos de Inclusão , Miosite , Humanos , Pessoa de Meia-Idade , Autoanticorpos , Relevância Clínica , República da Coreia
11.
J Clin Neurol ; 19(5): 460-468, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36929062

RESUMO

BACKGROUND AND PURPOSE: To understand the characteristics of Korean patients with anti-3-hydroxy-3-methylglutaryl-coenxyme A reductase (HMGCR) myopathy, we measured anti-HMGCR antibodies and analyzed the clinical, radiological, and pathological features of patients with anti-HMGCR myopathy. METHODS: We measured titers of anti-HMGCR antibodies in the sera of 99 patients with inflammatory myopathy, 36 patients with genetic myopathy, and 63 healthy subjects using an enzyme-linked immunosorbent assay. We tested 16 myositis-specific autoantibodies (MSAs) in all patients with anti-HMGCR myopathy. RESULTS: Positivity for the anti-HMGCR antibody was observed in 17 (4 males and 13 females) of 99 patients with inflammatory myopathy. The median age at symptom onset was 60 years. Ten (59%) of the patients with anti-HMGCR positivity had taken statins. The titer of anti-HMGCR antibodies was significantly higher in the statin-naïve group (median=230 U/mL, interquartile range=170-443 U/mL) than in the statin-exposed group (median=178 U/mL, interquartile range=105-210 U/mL, p=0.045). The most common symptom was proximal muscle weakness in 15 patients (88%), followed by myalgia in 9 (53%), neck weakness in 4 (24%), dysphagia in 3 (18%), and skin lesions in 2 (12%). The median titer of anti-HMGCR antibody was 202 U/mL. We found eight different MSAs in nine (53%) patients. The median disease duration from symptom onset to diagnosis was significantly shorter in the MSA-positive group than in the MSA-negative group (p=0.027). CONCLUSIONS: Our study was the first to measure anti-HMGCR antibodies in inflammatory myopathy. It has provided new findings, including the suggestion of the coexistence of other MSAs in Korean patients.

12.
Glia ; 60(2): 281-94, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22042562

RESUMO

The adult spinal cord contains a pool of endogenous glial precursor cells, which spontaneously respond to spinal cord injury (SCI) with increased proliferation. These include oligodendrocyte precursor cells that express the NG2 proteoglycan and can differentiate into mature oligodendrocytes. Thus, a potential approach for SCI treatment is to enhance the proliferation and differentiation of these cells to yield more functional mature glia and improve remyelination of surviving axons. We previously reported that soluble glial growth factor 2 (GGF2)- and basic fibroblast growth factor 2 (FGF2)-stimulated growth of NG2(+) cells purified from injured spinal cord in primary culture. This study examines the effects of systemic administration of GGF2 and/or FGF2 after standardized contusive SCI in vivo in both rat and mouse models. In Sprague-Dawley rats, 1 week of GGF2 administration, beginning 24 h after injury, enhanced NG2(+) cell proliferation, oligodendrogenesis, chronic white matter at the injury epicenter, and recovery of hind limb function. In 2',3'-cyclic-nucleotide 3'-phosphodiesterase-enhanced green fluorescent protein mice, GGF2 treatment resulted in increased oligodendrogenesis and improved functional recovery, as well as elevated expression of the stem cell transcription factor Sox2 by oligodendrocyte lineage cells. Although oligodendrocyte number was increased chronically after SCI in GGF2-treated mice, no evidence of increased white matter was detected. However, GGF2 treatment significantly increased levels of P0 protein-containing peripheral myelin, produced by Schwann cells that infiltrate the injured spinal cord. Our results suggest that GGF2 may have therapeutic potential for SCI by enhancing endogenous recovery processes in a clinically relevant time frame.


Assuntos
Regeneração Nervosa/efeitos dos fármacos , Neuregulina-1/fisiologia , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/tratamento farmacológico , Regulação para Cima , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Modelos Animais de Doenças , Feminino , Substâncias de Crescimento/biossíntese , Substâncias de Crescimento/fisiologia , Masculino , Camundongos , Camundongos Transgênicos , Fibras Nervosas Mielinizadas/patologia , Fibras Nervosas Mielinizadas/fisiologia , Regeneração Nervosa/fisiologia , Neuregulina-1/biossíntese , Neuregulina-1/farmacologia , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Recuperação de Função Fisiológica/genética , Células de Schwann/efeitos dos fármacos , Células de Schwann/fisiologia , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Regulação para Cima/genética
13.
J Neurosci ; 30(27): 9292-305, 2010 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-20610764

RESUMO

Extension of axonal and dendritic processes in the CNS is tightly regulated by outgrowth-promoting and -inhibitory cues to assure precision of synaptic connections. We identify a novel role for contactin-associated protein (Caspr) as an inhibitory cue that reduces neurite outgrowth from CNS neurons. We show that proteolysis of Caspr at the cell surface is regulated by the cellular form of prion protein (PrP), which directly binds to Caspr. PrP inhibits Reelin-mediated shedding of Caspr from the cell surface, thereby increasing surface levels of Caspr and potentiating the inhibitory effect of Caspr on neurite outgrowth. PrP deficiency results in reduced levels of Caspr at the cell surface, enhanced neurite outgrowth in vitro, and more efficient regeneration of axons in vivo following spinal cord injury. Thus, we reveal a previously unrecognized role for Caspr and PrP in inhibitory modulation of neurite outgrowth in CNS neurons, which is counterbalanced by the proteolytic activity of Reelin.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neuritos/fisiologia , Neurônios/citologia , Príons/metabolismo , Serina Endopeptidases/metabolismo , Animais , Biotinilação/métodos , Encéfalo/citologia , Células CHO , Catecolaminas/metabolismo , Moléculas de Adesão Celular/metabolismo , Moléculas de Adesão Celular Neuronais/deficiência , Células Cultivadas , Cerebelo/citologia , Cricetinae , Cricetulus , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática/métodos , Proteínas da Matriz Extracelular/deficiência , Feminino , Regulação da Expressão Gênica/genética , Cones de Crescimento/efeitos dos fármacos , Cones de Crescimento/fisiologia , Imunoprecipitação/métodos , Locomoção/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/deficiência , Neuritos/efeitos dos fármacos , Neurônios/ultraestrutura , Príons/genética , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/fisiologia , Recuperação de Função Fisiológica/genética , Proteína Reelina , Serina/metabolismo , Serina Endopeptidases/deficiência , Medula Espinal/citologia , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia , Frações Subcelulares/metabolismo , Fatores de Tempo , Transfecção/métodos
14.
J Neurosci Res ; 89(5): 628-38, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21337374

RESUMO

The close homolog of the adhesion molecule L1 (CHL1) is important during CNS development, but a study with CHL1 knockout mice showed greater functional recovery after spinal cord injury (SCI) in its absence. We investigated CHL1 expression from 1 to 28 days after clinically relevant contusive SCI in Sprague-Dawley rats. Western blot analysis showed that CHL1 expression was significantly up-regulated at day 1 and further increased over 4 weeks after SCI. Immunohistochemistry of tissue sections showed that CHL1 in the intact spinal cord was expressed at low levels. By 1 day and through 4 weeks after SCI, CHL1 became highly expressed in NG2(+) cells. Hypertrophic GFAP(+) astrocytes also expressed CHL1 by 1 week after injury. The increase in CHL1 protein paralleled that of NG2 in the first week and GFAP between 1 and 4 weeks after injury. At 4 weeks, NG2(+) /CHL1(+) cells and GFAP(+) /CHL1(+) astrocytes were concentrated at the boundary between residual spinal cord tissue and the central lesion. NF200(+) spinal cord axons approached but did not penetrate this boundary. In contrast, CHL1(+) cells in the central lesion at 1 week and later colabeled with p75 and NG2 and were chronically associated with many NF200(+) axons, presumably axons that had sprouted in association with CHL1(+) Schwann cells infiltrating the cord after contusion. Thus, our study demonstrates up-regulation of CHL1 in multiple cell types and locations in a rat model of contusion injury and suggests that this molecule may be involved both in inhibition of axonal regeneration and in recovery processes after SCI.


Assuntos
Moléculas de Adesão Celular Neurônio-Glia/biossíntese , Moléculas de Adesão Celular/biossíntese , Regeneração Nervosa/fisiologia , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Animais , Axônios/patologia , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular Neurônio-Glia/genética , Moléculas de Adesão Celular Neurônio-Glia/fisiologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Regeneração Nervosa/genética , Inibição Neural/genética , Inibição Neural/fisiologia , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/genética , Traumatismos da Medula Espinal/fisiopatologia , Fatores de Tempo
15.
Neural Regen Res ; 16(3): 550-560, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32985487

RESUMO

Despite emerging contemporary biotechnological methods such as gene- and stem cell-based therapy, there are no clinically established therapeutic strategies for neural regeneration after spinal cord injury. Our previous studies have demonstrated that transplantation of genetically engineered human umbilical cord blood mononuclear cells producing three recombinant therapeutic molecules, including vascular endothelial growth factor (VEGF), glial cell-line derived neurotrophic factor (GDNF), and neural cell adhesion molecule (NCAM) can improve morpho-functional recovery of injured spinal cord in rats and mini-pigs. To investigate the efficacy of human umbilical cord blood mononuclear cells-mediated triple-gene therapy combined with epidural electrical stimulation in the treatment of spinal cord injury, in this study, rats with moderate spinal cord contusion injury were intrathecally infused with human umbilical cord blood mononuclear cells expressing recombinant genes VEGF165, GDNF, NCAM1 at 4 hours after spinal cord injury. Three days after injury, epidural stimulations were given simultaneously above the lesion site at C5 (to stimulate the cervical network related to forelimb functions) and below the lesion site at L2 (to activate the central pattern generators) every other day for 4 weeks. Rats subjected to the combined treatment showed a limited functional improvement of the knee joint, high preservation of muscle fiber area in tibialis anterior muscle and increased H/M ratio in gastrocnemius muscle 30 days after spinal cord injury. However, beneficial cellular outcomes such as reduced apoptosis and increased sparing of the gray and white matters, and enhanced expression of heat shock and synaptic proteins were found in rats with spinal cord injury subjected to the combined epidural electrical stimulation with gene therapy. This study presents the first proof of principle study of combination of the multisite epidural electrical stimulation with ex vivo triple gene therapy (VEGF, GDNF and NCAM) for treatment of spinal cord injury in rat models. The animal protocols were approved by the Kazan State Medical University Animal Care and Use Committee (approval No. 2.20.02.18) on February 20, 2018.

16.
Neurochem Int ; 135: 104686, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31987865

RESUMO

Perinatal inflammation-induced reduction in pain threshold may alter pain sensitivity to hyperalgesia or allodynia which may persist into adulthood. In this study, we investigated the anti-inflammatory protective effect of interleukin-1 receptor antagonist (IL-1ra), an anti-inflammatory cytokine, on systemic lipopolysaccharide (LPS)-induced spinal cord inflammation and oxidative stress, thermal hyperalgesia, and mechanical allodynia in neonatal rats. Intraperitoneal (i.p.) injection of LPS (2 mg/kg) or sterile saline was performed in postnatal day 5 (P5) rat pups, and IL-1ra (100 mg/kg) or saline was administered (i.p.) 5 min after LPS injection. Pain reflex behavior, spinal cord inflammation and oxidative stress were examined 24 h after LPS administration. Systemic LPS exposure led to a reduction of tactile threshold in the von Frey filament tests (mechanical allodynia) and pain response latency in the tail-flick test (thermal hyperalgesia) of P6 neonatal rats. Spinal cord inflammation was indicated by the increased numbers of activated glial cells including microglia (Iba1+) and astrocytes (GFAP+), and elevated levels of pro-inflammatory cytokine interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) 24 h after LPS treatment. LPS treatment induced spinal oxidative stress as evidenced by the increase in thiobarbituric acid reactive substances (TBARS) content in the spinal cord. LPS exposure also led to a significant increase in oligodendrocyte lineage population (Olig2+) and mature oligodendrocyte cells (APC+) in the neonatal rat spinal cord. IL-1ra treatment significantly reduced LPS-induced effects including hyperalgesia, allodynia, the increased number of activated microglia, astrocytes and oligodendrocytes, and elevated levels of IL-1ß, COX-2, PGE2, and lipid peroxidation (TBARS) in the neonatal rat spinal cord. These data suggest that IL-1ra provides a protective effect against the development of pain hypersensitivity, spinal cord inflammation and oxidative stress in the neonatal rats following LPS exposure, which may be associated with the blockade of LPS-induced pro-inflammatory cytokine IL-1ß.


Assuntos
Hiperalgesia/tratamento farmacológico , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Lipopolissacarídeos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Receptores de Interleucina-1/antagonistas & inibidores , Medula Espinal/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Feminino , Hiperalgesia/induzido quimicamente , Hiperalgesia/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Masculino , Estresse Oxidativo/fisiologia , Medição da Dor/efeitos dos fármacos , Medição da Dor/métodos , Gravidez , Ratos , Ratos Sprague-Dawley , Receptores de Interleucina-1/metabolismo , Medula Espinal/metabolismo
17.
Microsyst Nanoeng ; 6: 98, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34567707

RESUMO

In this study, a mutual capacitive-type on-screen fingerprint sensor, which can recognize fingerprints on a display screen to provide smartphones with full-screen displays with a minimal bezel area, is fabricated. On-screen fingerprint sensors are fabricated using an indium tin oxide transparent conductor with a sheet resistance of ~10 Ω/sq. and a transmittance of ~94% (~86% with the substrate effect) in the visible wavelength range, and assembled onto a display panel. Even at this high transmittance, the electrodes can degrade the display quality when they are placed on the display. The interference between periodic display pixel arrays and sensor patterns can lead to the Moiré phenomenon. It is necessary to find an appropriate sensor pattern that minimizes the Moiré pattern, while maintaining the signal sensitivity. To search for appropriate patterns, a numerical calculation is carried out over wide ranges of pitches and rotation angles. The range is narrowed for an experimental evaluation, which is used to finally determine the sensor design. As the selected sensor pitches are too small to detect capacitance variations, three unit patterns are electrically connected to obtain a unit block generating a larger signal. By applying the selected sensor pattern and circuit driving by block, fingerprint sensing on a display is demonstrated with a prototype built on a commercial smartphone.

18.
Sci Rep ; 9(1): 4273, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30862809

RESUMO

Central sprouting of nociceptive afferents in response to neural injury enhances excitability of nociceptive pathways in the central nervous system, often causing pain. A reliable quantification of central projections of afferent subtypes and their synaptic terminations is essential for understanding neural plasticity in any pathological condition. We previously characterized central projections of cutaneous nociceptive A and C fibers, selectively labeled with cholera toxin subunit B (CTB) and Isolectin B4 (IB4) respectively, and found that they expressed a general synaptic molecule, synaptophysin, largely depending on afferent subtypes (A vs. C fibers) across thoracic dorsal horns. The current studies extended the central termination profiles of nociceptive afferents with synaptoporin, an isoform of synaptophysin, known to be preferentially expressed in C fibers in lumbar dorsal root ganglions. Our findings demonstrated that synaptophysin was predominantly expressed in both peptidergic and IB4-binding C fiber populations in superficial laminae of the thoracic dorsal horn. Cutaneous IB4-labeled C fibers showed comparable expression levels of both isoforms, while cutaneous CTB-labeled A fibers exclusively expressed synaptophysin. These data suggest that central expression of synaptophysin consistently represents synaptic terminations of projecting afferents, at least in part, including nociceptive A-delta and C fibers in the dorsal horn.


Assuntos
Corno Dorsal da Medula Espinal/metabolismo , Medula Espinal/metabolismo , Sinaptofisina/metabolismo , Animais , Feminino , Imuno-Histoquímica , Microscopia Confocal , Fibras Nervosas Mielinizadas/metabolismo , Fibras Nervosas Amielínicas/metabolismo , Nociceptores/metabolismo , Ratos , Ratos Long-Evans , Sinaptofisina/genética
19.
Ther Deliv ; 10(4): 251-263, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30991923

RESUMO

Therapeutic strategies for traumatic injuries in the central nervous system (CNS) are largely limited to the efficiency of drug delivery. Despite the disrupted blood-CNS barrier during the early phase after injury, the drug administration faces a variety of obstacles derived from homeostatic imbalance at the injury site. In the late phase after CNS injury, the restoration of the blood-CNS barrier integrity varies depending on the injury severity resulting in inconsistent delivery of therapeutics. This review intends to characterize those different challenges of the therapeutic delivery in acute and chronic phases after injury and discuss recent advances in various approaches to explore novel strategies for the treatment of traumatic CNS injury.


Assuntos
Lesões Encefálicas Traumáticas/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Traumatismos da Medula Espinal/tratamento farmacológico , Doença Aguda , Animais , Barreira Hematoencefálica/metabolismo , Lesões Encefálicas Traumáticas/fisiopatologia , Doença Crônica , Humanos , Traumatismos da Medula Espinal/fisiopatologia , Distribuição Tecidual , Índices de Gravidade do Trauma
20.
J Magn Reson ; 300: 149-152, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30776565

RESUMO

The development of atomic magnetometers has led to nuclear magnetic resonance (NMR) in zero and ultralow magnetic fields without using cryogenic sensors. However, in-situ detection, meaning that a sample locates in the detection space beside a vapor cell, has been conducted only with parahydrogen-induced polarization. Other hyperpolarization techniques remain unexplored yet. In this work, we demonstrate that Overhauser dynamic nuclear polarization allows in-situ NMR detection with an atomic magnetometer at less than 1 µT. The 1H NMR signal of a nitroxide radical solution was observed at 13.83 Hz, which corresponds to 325 nT. Signal-to-noise ratio was 32 after sixteen averages. On the Larmor precession of 1H spins, a decaying oscillation was superimposed. We attribute it to a transient 87Rb spin precession in response to a non-adiabatic field variation. This work shows a new capability of zero- and ultralow-field NMR.

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