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Oxygenated water (OW) contains more oxygen than normal drinking water. It may induce oxygen enrichment in the blood and reduce oxidative stress. Hypoxia and oxidative stress could be involved in epilepsy. We aimed to examine the effects of OW-treated vs. control on four rodent models of epilepsy: (1) prenatal betamethasone priming with postnatal N-methyl-D-aspartate (NMDA)-triggered spasm, (2) no prenatal betamethasone, (3) repetitive kainate injection, and (4) intraperitoneal pilocarpine. We evaluated, in (1) and (2), the latency to onset and the total number of spasms; (3) the number of kainate injections required to induce epileptic seizures; (4) spontaneous recurrent seizures (SRS) (numbers and duration). In model (1), the OW-treated group showed significantly increased latency to onset and a decreased total number of spasms; in (2), OW completely inhibited spasms; in (3), the OW-treated group showed a significantly decreased number of injections required to induce epileptic seizures; and in (4), in the OW-treated group, the duration of a single SRS was significantly reduced. In summary, OW may increase the seizure threshold. Although the underlying mechanism remains unclear, OW may provide an adjunctive alternative for patients with refractory epilepsy.
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Epilepsia , Roedores , Animais , Ácido Caínico , Água , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Espasmo , Betametasona , OxigênioRESUMO
A type of ultrathin films has been developed for suppressing capsule formation induced by medical silicone implants and hence reducing the inflammation response to such formation and the differentiation to myofibroblasts. The films were each fabricated from hyaluronic acid (HA) and modified ß-cyclodextrin (Mod-ß-CyD) polymer which was synthesized with a cyclodextrin with partially substituted quaternary amine. Ultrathin films comprising HA and Mod-ß-CyD or poly(allylamine hydrochloride) (PAH) were fabricated by using a layer-by-layer dipping method. The electrostatic interactions produced from the functional groups of Mod-ß-CyD and HA influenced the surface morphology, wettability, and bio-functional activity of the film. Notably, medical silicone implants coated with PAH/HA and Mod-ß-CyD multilayers under a low pH condition exhibited excellent biocompatibility and antibiofilm and anti-inflammation properties. Implantation of these nanoscale film-coated silicones showed a reduced capsular thickness as well as reduced TGFß-SMAD signaling, myofibroblast differentiation, biofilm formation, and inflammatory response levels. We expect our novel coating system to be considered a strong candidate for use in various medical implant applications in order to decrease implant-induced capsule formation.
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Infecções Bacterianas , beta-Ciclodextrinas , Humanos , Ácido Hialurônico/química , Polímeros , Silicones/químicaRESUMO
Targeting microglial activation is emerging as a clinically promising drug target for neuropathic pain treatment. Fexofenadine, a histamine receptor 1 antagonist, is a clinical drug for the management of allergic reactions as well as pain and inflammation. However, the effect of fexofenadine on microglial activation and pain behaviors remains elucidated. Here, we investigated nanomedicinal approach that targets more preferentially microglia and long-term analgesics. Fexofenadine significantly abolished histamine-induced microglial activation. The fexofenadine-encapsulated poly(lactic-co-glycolic acid) nanoparticles (Fexo NPs) injection reduced the pain sensitivity of spinal nerve ligation rats in a dose-dependent manner. This alleviation was sustained for 4 days, whereas the effective period by direct fexofenadine injection was 3 h. Moreover, Fexo NPs inhibited microglial activation, inflammatory signaling, cytokine release, and a macrophage phenotype shift towards the alternative activated state in the spinal cord. These results show that Fexo NPs exhibit drug repositioning promise as a long-term treatment modality for neuropathic pain.
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Nanopartículas , Neuralgia , Animais , Microglia , Neuralgia/genética , Ratos , Medula Espinal , Nervos Espinhais , Terfenadina/análogos & derivadosRESUMO
Duloxetine (DLX) is a selective serotonin and noradrenaline reuptake inhibitor (SNRI) used for the treatment of pain, but it has been reported to show side effects in 10-20% of patients. Its analgesic efficacy in central pain is putatively related to its influence on descending inhibitory neuronal pathways. However, DLX can also affect the activation of microglia. This study was performed to investigate whether PLGA nanoparticles (NPs), which are expected to enhance targeting to microglia, can improve the analgesic efficacy and limit the side effects of DLX. PLGA NPs encapsulating a low dose of DLX (DLX NPs) were synthesized and characterized and their localization was determined. The analgesic and anti-inflammatory effects of DLX NPs were evaluated in a spinal nerve ligation (SNL)-induced neuropathic pain model. The analgesic effect of DLX lasted for only a few hours and disappeared within 1 day. However, DLX NPs alleviated mechanical allodynia, and the effect was maintained for 1 week. DLX NPs were localized to the spinal microglia and suppressed microglial activation, phosphorylation of p38/NF-κB-mediated pathways and the production of inflammatory cytokines in the spinal dorsal horn of SNL rats. We demonstrated that DLX NPs can provide a prolonged analgesic effect by enhanced targeting of microglia. Our observations imply that DLX delivery through nanoparticle encapsulation allows drug repositioning with a prolonged analgesic effect, and reduces the potential side effects of abuse and overdose.
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Nanopartículas , Neuralgia , Animais , Cloridrato de Duloxetina , Humanos , Microglia , Neuralgia/tratamento farmacológico , Ratos , Ratos Sprague-DawleyRESUMO
Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic steatohepatitis (NASH), affects 25% of the global population. Despite the prevalence of NAFLD worldwide, effective therapeutics are currently lacking. Amomum villosum var. xanthioides (Wall. ex Baker) T.L.Wu & S.J.Chen (AX) is a medicinal herb traditionally used for treating digestive tract disorders in countries across Asia. We aimed to examine the pharmacological effects of the ethyl acetate fraction of AX (AXEF) against tunicamycin (TM)-induced ER stress in a NASH mouse model using C57/BL6J male mice. Following TM injections (2 mg/kg), the mice were orally administrated AXEF (12.5, 25, or 50 mg/kg), silymarin (50 mg/kg), or distilled water daily for 5 days, and the outcomes for fatty liver, inflammation, and oxidative stress were measured in serum or liver tissue levels. AXEF drastically attenuated hepatic ER stress-induced NASH as indicated by decreases in lipid droplet accumulations, serum liver enzymes, hepatic inflammations, and cell death signals in the hepatic tissue and/or serum levels. Interestingly, AXEF showed potent antioxidant effects by quenching reactive oxidative stress and its final product lipid peroxide in the hepatic tissue, specifically an increase in metallothionein (MT). To confirm the underlying actions of AXEF, we observed that AXEF increases MT1 gene promoter activities in the physiological levels. Collectively, AXEF showed antioxidant properties on TM-induced ER stress in a NASH mice model through the improvement of MTs.
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[This corrects the article DOI: 10.3389/fgene.2020.590924.].
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Reactive oxygen species (ROS) exacerbate stroke-induced cell damage. We found that ShcA, a protein that regulates ROS, is highly expressed in a Rose Bengal photothrombosis model. We investigated whether ShcA is essential for mitophagy in ROS-induced cellular damage and determined whether ROS exacerbate mitochondrial dysfunction via ShcA protein expression. Ischemic stroke was generated by Rose Bengal photothrombosis in mice. To silence ShcA protein expression in the mouse brain, ShcA-targeting siRNA-encapsulated nanoparticles were intrathecally injected into the cisterna magna. Upon staining with antibodies against ShcA counterpart caspase-3 or NeuN, we found that the ShcA protein expression was increased in apoptotic neurons. In addition, mitochondrial dysfunction and excessive mitophagy were evident in photothrombotic stroke tissue. Infarct volumes were significantly reduced, and neurological deficits were diminished in the ShcA siRNA nanoparticle-treated group, compared with the negative control siRNA nanoparticle-treated group. We confirmed that the reduction of ShcA expression by nanoparticle treatment rescued the expression of genes, associated with mitochondrial dynamics and mitophagy mediation in a stroke model. This study suggests that the regulation of ShcA protein expression can be a therapeutic target for reducing brain damage with mitochondrial dysfunction caused by thrombotic infarction.
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Isquemia Encefálica , Acidente Vascular Cerebral , Animais , Infarto Cerebral/etiologia , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de SrcRESUMO
BACKGROUND: Prenatal stress increases the susceptibility of infants to seizures and is known to be associated with oxidative stress. Recent studies suggest that vitamin E has beneficial effects in various neurological diseases due to its antioxidant properties. In this study, we investigated the relationship between prenatal stress and vitamin E treatment on N-methyl-D-aspartate (NMDA)-induced spasms. METHODS: We used pregnant female Sprague Dawley rats and induced prenatal stress with an injection of betamethasone on G15. They were then treated orally with 200â¯mg/kg vitamin E or saline twice a day from G15-G21. On postnatal day 15, NMDA was administered to trigger spasms in offspring. The total number of spasms and latency to the first spasm were recorded. We also measured oxidative stress in the medial cortex using western blot, and calpain activity, thiobarbituric acid reactive substances (TBARS), glutathione (GSH)/GSH/glutathione disulfide (GSSG), superoxide dismutase (SOD) activity, catalase activity, and nitric oxide (NO) assays. RESULTS: We observed that rats treated with vitamin E while exposed to prenatal stress demonstrated reduced total number and frequency of spasms. Expression of glutamate decarboxylase 67 (GAD67) and K+/Cl- co-transporter (KCC2) were reduced after prenatal stress; this recovered in the vitamin E treated group. Further, expression of calpain 2 was decreased and various markers of oxidative stress (malondialdehyde (MDA), GSH/GSSG, SOD, catalase, and NO) were reduced in the vitamin E treated group. CONCLUSIONS: Our results provide evidence that vitamin E lowers oxidative stress and decreases seizure susceptibility in rat offspring exposed to prenatal stress. Given the well-known safety profile of vitamin E, these results indicate its potential as a strategy for preventing seizures.
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Calpaína , Vitamina E , Animais , Antioxidantes , Catalase/metabolismo , Feminino , Glutationa/metabolismo , Estresse Oxidativo , Gravidez , Ratos , Ratos Sprague-Dawley , Espasmo , Superóxido Dismutase/metabolismo , Vitamina E/uso terapêuticoRESUMO
Because inflammation in osteoarthritis (OA) is related to the Toll-like receptor 4 (TLR4) signaling cascades, TLR4 is a reasonable target for developing therapeutics for OA. Thus, we investigated whether TAP2, a peptide antagonist of TLR4, reduces the monoiodoacetate (MIA)-induced arthritic pain and cartilage degradation in rats. TLR4 expression of human OA chondrocytes and synoviocytes and the knee joint tissue of MIA-induced arthritis were evaluated. MIA-induced arthritic model using Sprague-Dawley rats (6 week-old-male) were treated with TAP2, a TLR4 antagonist, and evaluated with behavioral test, immunohistochemistry, and quantitative PCR. TLR4 was highly expressed in the knee joints of patients with OA and the MIA-induced rat model. Further, a single intraarticular injection of TAP2 (25 nmol/rat) molecules targeting TLR4 on day 7 after MIA injection dramatically attenuated pain behavior for about 3 weeks and reduced cartilage loss in the knee joints and microglial activation in the spinal dorsal horns. Likewise, the mRNA levels of TNFα and IL-1ß, reactive oxygen species, and the expression of MMP13 in the knee joints of TAP2-treated rats was significantly decreased by TAP2 treatment compared with the control. Moreover, interestingly, the duration of OA pain relief by TAP2 was much longer than that of chemical TLR4 antagonists, such as C34 and M62812. In conclusion, TAP2 could effectively attenuate MIA-induced arthritis in rats by blocking TLR4 and its successive inflammatory cytokines and MMP13. Therefore, TAP2 could be a prospective therapeutic to treat patients with OA.
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Membro 3 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/química , Osteoartrite/tratamento farmacológico , Dor/tratamento farmacológico , Receptor 4 Toll-Like/antagonistas & inibidores , Animais , Artrite Experimental/induzido quimicamente , Artrite Experimental/tratamento farmacológico , Cartilagem Articular/citologia , Células Cultivadas , Condrócitos/citologia , Modelos Animais de Doenças , Humanos , Inflamação , Ácido Iodoacético , Masculino , Metaloproteinase 13 da Matriz/química , Inibidores de Metaloproteinases de Matriz/química , Osteoartrite/induzido quimicamente , Manejo da Dor , Peptídeos/química , Ratos , Ratos Sprague-Dawley , Sinoviócitos/citologiaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Yuk-Mi-Jihwang-Tang (YJT) has been popularly prescribed to treat aging related disorders over than hundreds of years in East Asia countries. AIM OF THE STUDY: To investigate possible modulatory actions of YJT on chronic restraint stress (CRS)-induced neurodegeneration on hippocampus neuronal injuries. MATERIALS AND METHODS: Mice were orally administered with YJT (100, 200, or 400 mg/kg) or ascorbic acid (100 mg/kg) before 4 h of stress for 28 days. Morris water maze task was completed from day 24th to 28th, and stress hormones and biochemical analyzes were measured. RESULTS: Four weeks of the CRS abnormally affected memory impairments by measurement of escape latency and time spent in the target quadrant. Additionally, neurotransmitters were also drastically altered in serum or hippocampus protein levels by CRS. Gene expressions for 5-hydroxytryptamine (5-HT) receptor, 5-HT-transport, and tryptophan hydroxylase were also altered, whereas YJT led to normalize the above alterations. Additionally, YJT also beneficially worked on endogenous redox system as well as inflammatory reactions in the hippocampal neurons. We observed that hippocampal excitotoxicity was induced by CRS which were evidenced by depletion of phosphor-cAMP response element-binding protein, brain-derived neurotrophic factor, nuclear factor erythroid-2-related factor 2, heme oxygenase-1 and abnormally increases of acetylcholine esterase activities in hippocampus protein levels; however, YJT considerably improved the above pathological conditions. CONCLUSIONS: Our findings supported YJT enhance memory function via regulation of hippocampal excitotoxicity-derived memory impairment, stress hormone, and endogenous redox, respectively.
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Comportamento Animal/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Hipocampo/efeitos dos fármacos , Transtornos da Memória/prevenção & controle , Memória/efeitos dos fármacos , Degeneração Neural , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Nootrópicos/farmacologia , Estresse Psicológico/tratamento farmacológico , Animais , Doença Crônica , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Hipocampo/patologia , Mediadores da Inflamação/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Transtornos da Memória/psicologia , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Oxirredução , Restrição Física , Estresse Psicológico/metabolismo , Estresse Psicológico/patologia , Estresse Psicológico/psicologiaRESUMO
Aims: We investigated whether miRNA (miR) 146a-5p-loaded nanoparticles (NPs) can attenuate neuropathic pain behaviors in the rat spinal nerve ligation-induced neuropathic pain model by inhibiting activation of the NF-κB and p38 MAPK pathways in spinal microglia. Materials & methods: After NP preparation, miR NPs were assessed for their physical characteristics and then injected intrathecally into the spinal cords of rat spinal nerve ligation rats to test their analgesic effects. Results: miR NPs reduced pain behaviors for 11 days by negatively regulating the inflammatory response in spinal microglia. Conclusion: The anti-inflammatory effects of miR 146a-5p along with nanoparticle-based materials make miR NPs promising tools for treating neuropathic pain.
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MicroRNAs , Nanopartículas , Neuralgia , Animais , Glicolatos , Glicóis , Ácido Láctico , MicroRNAs/genética , Microglia , Neuralgia/tratamento farmacológico , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Osteoarthritis (OA) is the most common type of joint disease associated with cartilage breakdown. However, the role played by mitochondrial dysfunction in OA remains inadequately understood. Therefore, we investigated the role played by p66shc during oxidative damage and mitochondrial dysfunction in OA and the effects of p66shc downregulation on OA progression. METHODS: Monosodium iodoacetate (MIA), which is commonly used to generate OA animal models, inhibits glycolysis and biosynthetic processes in chondrocytes, eventually causing cell death. To observe the effects of MIA and poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles, histological analysis, immunohistochemistry, micro-CT, mechanical paw withdrawal thresholds, quantitative PCR, and measurement of oxygen consumption rate and extracellular acidification rate were conducted. RESULTS: p-p66shc was highly expressed in cartilage from OA patients and rats with MIA-induced OA. MIA caused mitochondrial dysfunction and reactive oxygen species (ROS) production, and the inhibition of p66shc phosphorylation attenuated MIA-induced ROS production in human chondrocytes. Inhibition of p66shc by PLGA-based nanoparticles-delivered siRNA ameliorated pain behavior, cartilage damage, and inflammatory cytokine production in the knee joints of MIA-induced OA rats. CONCLUSION: p66shc is involved in cartilage degeneration in OA. By delivering p66shc-siRNA-loaded nanoparticles into the knee joints with OA, mitochondrial dysfunction-induced cartilage damage can be significantly decreased. Thus, p66shc siRNA PLGA nanoparticles may be a promising option for the treatment of OA.
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Mitocôndrias/patologia , Osteoartrite/tratamento farmacológico , RNA Interferente Pequeno/farmacologia , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/genética , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/metabolismo , Animais , Cartilagem Articular/metabolismo , Condrócitos/efeitos dos fármacos , Condrócitos/metabolismo , Condrócitos/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Ácido Iodoacético/toxicidade , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/efeitos dos fármacos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/uso terapêutico , Osteoartrite/induzido quimicamente , Osteoartrite/patologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , RNA Interferente Pequeno/administração & dosagem , Ratos Sprague-DawleyRESUMO
Osteoarthritis (OA) is the most common joint disorder that has had an increasing prevalence due to the aging of the population. Recent studies have concluded that OA progression is related to oxidative stress and reactive oxygen species (ROS). ROS are produced at low levels in articular chondrocytes, mainly by the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and ROS production and oxidative stress have been found to be elevated in patients with OA. The cartilage of OA-affected rat exhibits a significant induction of p47phox, a cytosolic subunit of the NADPH oxidase, similarly to human osteoarthritis cartilage. Therefore, this study tested whether siRNA p47phox that is introduced with poly (D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (p47phox si_NPs) can alleviate chondrocyte cell death by reducing ROS production. Here, we confirm that p47phox si_NPs significantly attenuated oxidative stress and decreased cartilage damage in mono-iodoacetate (MIA)-induced OA. In conclusion, these data suggest that p47phox si_NPs may be of therapeutic value in the treatment of osteoarthritis.
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Lennox-Gastaut syndrome (LGS) is a severe type of childhood-onset epilepsy characterized by multiple types of seizures, specific discharges on electroencephalography, and intellectual disability. Most patients with LGS do not respond well to drug treatment and show poor long-term prognosis. Approximately 30% of patients without brain abnormalities have unidentifiable causes. Therefore, accurate diagnosis and treatment of LGS remain challenging. To identify causative mutations of LGS, we analyzed the whole-exome sequencing data of 17 unrelated Korean families, including patients with LGS and LGS-like epilepsy without brain abnormalities, using the Genome Analysis Toolkit. We identified 14 mutations in 14 genes as causes of LGS or LGS-like epilepsy. 64 percent of the identified genes were reported as LGS or epilepsy-related genes. Many of these variations were novel and considered as pathogenic or likely pathogenic. Network analysis was performed to classify the identified genes into two network clusters: neuronal signal transmission or neuronal development. Additionally, knockdown of two candidate genes with insufficient evidence of neuronal functions, SLC25A39 and TBC1D8, decreased neurite outgrowth and the expression level of MAP2, a neuronal marker. These results expand the spectrum of genetic variations and may aid the diagnosis and management of individuals with LGS.
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Cartilage loss is a central event in the pathogenesis of osteoarthritis (OA), though other than mechanical loading, the biochemical mechanisms underlying OA pathology remain poorly elucidated. We investigated the role of Pink1-mediated mitophagy in mitochondrial fission, a crucial process in OA pathogenesis. We used a monosodium iodoacetate (MIA)-induced rodent model of OA, which inhibits the activity of articular chondrocytes, leading to disruption of glycolytic energy metabolism and eventual cell death. The OA rat cartilage exhibits significant induction of autophagy-related proteins LC3B and p62, similar to human osteoarthritic cartilage. Moreover, expression of Pink1 and Parkin proteins were also increased in OA. Here, we confirm that Pink1-mediated mitophagy leads to cell death in chondrocytes following MIA treatment, while deficiency in Pink1 expression was associated with decreased cartilage damage and pain behaviors in MIA-induced OA. Finally, we found that autophagy and mitophagy-related genes are highly expressed in human osteoarthritic cartilage. These results indicate that OA is a degenerative condition associated with mitophagy, and suggest that targeting the Pink1 pathway may provide a therapeutic avenue for OA treatment.
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Upon peripheral nerve injury, vesicular ATP is released from damaged primary afferent neurons. This extracellular ATP subsequently activates purinergic receptors of the spinal cord, which play a critical role in neuropathic pain. As an inhibitor of the vesicular nucleotide transporter (VNUT), Evans blue (EB) inhibits the vesicular storage and release of ATP in neurons. Thus, we tested whether EB could attenuate neuropathic pain behavior induced by spinal nerve ligation (SNL) in rats by targeting VNUT. An intrathecal injection of EB efficiently attenuated mechanical allodynia for five days in a dose-dependent manner and enhanced locomotive activity in an SNL rat model. Immunohistochemical analysis showed that EB was found in VNUT immunoreactivity on neurons in the dorsal root ganglion and the spinal dorsal horn. The level of ATP in cerebrospinal fluid in rats with SNL-induced neuropathic pain decreased upon administration of EB. Interestingly, EB blocked ATP release from neurons, but not glial cells in vitro. Eventually, the loss of ATP decreased microglial activity in the ipsilateral dorsal horn of the spinal cord, followed by a reduction in reactive oxygen species and proinflammatory mediators, such as interleukin (IL)-1ß and IL-6. Finally, a similar analgesic effect of EB was demonstrated in rats with monoiodoacetate-induced osteoarthritis (OA) pain. Taken together, these data demonstrate that EB prevents ATP release in the spinal dorsal horn and reduces the ATP/purinergic receptor-induced activation of spinal microglia followed by a decline in algogenic substances, thereby relieving neuropathic pain in rats with SNL.
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Trifosfato de Adenosina/líquido cefalorraquidiano , Azul Evans/farmacologia , Neuralgia , Coluna Vertebral , Animais , Modelos Animais de Doenças , Gânglios Espinais/metabolismo , Gânglios Espinais/patologia , Gânglios Espinais/fisiopatologia , Interleucina-1beta/líquido cefalorraquidiano , Interleucina-6/líquido cefalorraquidiano , Masculino , Neuralgia/líquido cefalorraquidiano , Neuralgia/tratamento farmacológico , Neuralgia/patologia , Neuralgia/fisiopatologia , Neurônios/metabolismo , Neurônios/patologia , Ratos , Ratos Sprague-Dawley , Coluna Vertebral/metabolismo , Coluna Vertebral/patologia , Coluna Vertebral/fisiopatologiaRESUMO
Stress can induce a serious epileptic encephalopathy that occurs during early infancy. Recent studies have revealed that prenatal stress exposure is a risk factor for the development of infantile spasms. Our previous work demonstrates that prenatal stress with betamethasone-induced alterations to the expression of the K+/Cl- co-transporter (KCC2) in gamma-aminobutyric acid (GABA) interneurons lowers the seizure threshold in exposed animals. Here, we further investigated the mechanisms involved in this KCC2 dysfunction and explored possible treatment options. We stressed Sprague-Dawley rats prenatally and further treated dams with betamethasone on gestational day 15, which increases seizure susceptibility and NMDA (N-Methyl-D-aspartate)-triggered spasms on postnatal day 15. In this animal model, first, we evaluated baseline calpain activity. Second, we examined the cleavage and dephosphorylation of KCC2. Finally, we checked the effect of a calpain inhibitor on seizure occurrence. The phosphorylated-N-methyl-Daspartate Receptor 2B (NR2B):non-phosphorylated NR2B ratio was found to be higher in the cortex of the prenatally stressed betamethasone model. We further found that the betamethasone model exhibited increased phosphorylation of calpain-2 and decreased phosphorylation of KCC2 and Glutamic acid decarboxylase 67 (GAD67). After using a calpain inhibitor in prenatal-stress rats, the seizure frequency decreased, while latency increased. GABAergic depolarization was further normalized in prenatal-stress rats treated with the calpain inhibitor. Our study suggests that calpain-dependent cleavage and dephosphorylation of KCC2 decreased the seizure threshold of rats under prenatal stress. Calpain-2 functions might, thus, be targeted in the future for the development of treatments for epileptic spasms.
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AIMS: Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease thought to be caused by repetitive traumatic brain injury (TBI) and subconcussive injuries. While hyperphosphorylation of tau (p-Tau), which is attributed to astrocytic tangles (ATs) and neurofibrillary tangles, is known to be involved in CTE, there are limited neuropathological or molecular data. By utilizing repetitive mild TBI (rmTBI) mouse models, our aim was to examine the pathological changes of CTE-associated structures, specifically the ATs. RESULTS: Our rmTBI mouse models showed symptoms of depressive behavior and memory deficit, alongside an increased p-Tau expression in their neurons and astrocytes in both the hippocampus and cortex. rmTBI induced oxidative stress in endothelial cells and nitric oxide (NO) generation in astrocytes, which were mediated by hypoxia and increased hypoxia-inducible factor 1-α (HIF1α). There was also correlated decreased regional cerebral tissue perfusion units, mild activation of astrocytes and NFκB phosphorylation, increased expression of inducible nitric oxide synthase (iNOS), increased endothelial nitric oxide synthase (eNOS) uncoupling with decreased tetrahydrobiopterin, and increased expression of nitrotyrosine, NADPH oxidase 2 (Nox2)/nuclear factor (erythroid-derived 2) factor 2 (Nrf2) signaling proteins. Combined, these effects induced peroxynitrite formation and hyperphosphorylation of tau in the hippocampus and cortex toward the formation of ATs. INNOVATION: Our model features molecular pathogenesis events of CTE with clinically relevant latency periods. In particular, this is the first demonstration of an increased astrocytic iNOS expression in an in vivo model. CONCLUSION: We propose a novel mechanism of uncoupled eNOS and NO contribution to Tau phosphorylation and AT formation in rmTBI brain, toward an increased molecular understanding of the pathophysiology of human CTE.
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Encefalopatia Traumática Crônica/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Proteínas tau/metabolismo , Animais , Astrócitos/metabolismo , Encéfalo/metabolismo , Encefalopatia Traumática Crônica/etiologia , Modelos Animais de Doenças , Expressão Gênica , Hipocampo/metabolismo , Hipóxia/metabolismo , Camundongos , Microglia/metabolismo , NF-kappa B/metabolismo , Neurônios/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Oxirredução , Fosforilação , Proteínas tau/genéticaRESUMO
PURPOSE: Headache is a common symptom during childhood. It is usually persistent and requires special care. This study aimed to identify the characteristics of headache in children <7 years of age. METHODS: We reviewed 3 years of clinical files on children <7 years of age with a chief complaint of headache. RESULTS: This study included 146 children (66 males, 80 females; mean age, 5.5±1.0 years). Mean symptom duration was 5.8±7.9 months. Attack durations were longer than 2 hours in 31 patients, shorter than 2 hours in 70 patients, and unchecked in 45 patients. Attack frequency was 15.1±10.6 times per month. Pain locations and characteristics were also variable. Mean pain severity score was 5.1±2.2 on the visual analog scale. Of 38 patients who underwent electroencephalography, 9 showed positive findings. Of 41 who underwent brain magnetic resonance imaging, 20 showed positive findings. The diagnoses were migraine (including probable migraine) in 34, tension-type headache in 5, and congenital malformations in 3. Medications were used in 29 patients: acetaminophen in 17, ibuprofen in 8, naproxen sodium in 1, and topiramate or amitriptyline in 3. CONCLUSION: In children aged <7 years, headache has a relatively benign course, but detailed history taking is needed for more accurate diagnosis.
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PURPOSE: Sacral dimples are a common cutaneous anomaly in infants. Spine ultrasonography (USG) is an effective and safe screening tool for patients with a sacral dimple. The aim of this study was to determine the clinical manifestations in patients with an isolated sacral dimple and to review the management of spinal cord abnormalities identified with USG. METHODS: We reviewed clinical records and collected data on admissions for a sacral dimple from March 2014 through February 2017 that were evaluated with spine USG by a pediatric radiologist. During the same period, patients who were admitted for other complaints, but were found to have a sacral dimple were also included. RESULTS: This study included 230 infants under 6-months-old (130 males and 100 females; mean age 52.8±42.6 days). Thirty-one infants with a sacral dimple had an echogenic filum terminale, and 57 children had a filar cyst. Twenty-seven patients had a low-lying spinal cord, and only one patient was suspected of having a tethered cord. Follow-up spine USG was performed in 28 patients, which showed normalization or insignificant change. CONCLUSION: In this study, all but one infant with a sacral dimple had benign imaging findings. USG can be recommended in infants with a sacral dimple for its convenience and safety.