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As an autophagic adaptor, p62 specifically targets ubiquitinated proteins to an autophagosome for lysosomal degradation through a critical ubiquitin-associated (UBA) domain. Recent research studies reported that the Ser403 and Ser407 sites on the UBA domain were modified by phosphorylation, increasing the binding affinity between p62 and ubiquitin (Ub). However, the exact role of each phosphorylation site in the regulation of the UBA domain and Ub binding remains unclear. In this text, we applied total chemical synthesis to prepare four types of phosphorylated UBAs, among which the bisphosphorylated UBA was successfully synthesized via the pseudo-dipeptide unit and auxiliary-mediated hydrazide-based native chemical ligation (NCL). Isothermal titration calorimetry (ITC) assays showed that the phosphorylation at S407 enhanced the binding affinity between UBA and Ub, while that at S403 did not. It was suggested that phosphorylation at S407 might be important for promoting the interplay between the UBA domain and Ub, whereas phosphorylation at S403 was not directly involved in this interaction.
Assuntos
Ubiquitina , Ligação ProteicaRESUMO
ABSRACT: Hospital stay and mortality in high-risk patients after noncardiac surgery has been associated with a triple low anesthesia. However, the association between anesthesia-related factors and perioperative outcome after cardiac surgery remains unclear.We tested the effect of a novel triple low state: low mean arterial pressure (MAP) <65 mmHg and low bispectral index (BIS) <45 during a low target effect-site concentration (Ce) <1.5 µg ml-1 of propofol anesthesia on postoperative duration of hospitalization and 30-day mortality in cardiac valvular patients. In this prospective observational study, univariable and multivariable logistic regression analyses were used to determine whether perioperative factors, in particular, cumulative duration of triple low state were independently associated with duration of hospitalization and 30-day mortality among patients who underwent elective valvular replacement. 489 patients were included in the final analysis. After adjusting for related covariates, cumulative duration of the triple-low state was not associated with prolonged hospitalization (multivariable odds ratio: 1.007; 95 % confidence interval 0.997-1.017; P = 0.564), but was a significant predictor of 30-day mortality (multivariable odds ratio: 1.016; 95 % confidence interval 1.002-1.031; P = 0.030). Compared to a triple-low duration of <15 min, a duration >60 min increased the 30-day mortality rate by 8 times. After adjusting for patient- and procedure-related characteristics, the cumulative duration of a triple-low state (intraoperative low MAP, low BIS, and low Ce) was associated with poorer 30-day mortality, but not with prolonged duration of hospital stay.The mortality risk was even greater when a cumulative time >60 min.
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Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Cardiopatias/mortalidade , Cardiopatias/cirurgia , Adulto , Anestesia/efeitos adversos , Valva Aórtica , Pressão Arterial , Pressão Sanguínea , Monitores de Consciência , Ponte de Artéria Coronária , Procedimentos Cirúrgicos Eletivos/efeitos adversos , Feminino , Próteses Valvulares Cardíacas , Mortalidade Hospitalar , Hospitalização , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Razão de Chances , Período Perioperatório , Estudos Prospectivos , Análise de Regressão , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Our previous studies have demonstrated that EphBs receptors and ephrinBs ligands were involved in modulation of spinal nociceptive information. However, the downstream mechanisms that control this process are not well understood. The aim of this study was to further investigate whether mitogen-activated protein kinases (MAPKs), as the downstream effectors, participate in modulation of spinal nociceptive information related to ephrinBs/EphBs. METHODS: Thermal hyperalgesia and mechanical allodynia were measured using radiant heat and von Frey filaments test. Immunofluorescence staining was used to detect the expression of p-MAPKs and of p-MAPKs/neuronal nuclei, or p-MAPKs/glial fibrillary acidic protein double label. C-Fos expression was determined by immunohistochemistry. The expression of p-MAPKs was also determined by Western blot assay. RESULTS: Intrathecal injection of ephrinB1-Fc produced a dose- and time-dependent thermal and mechanical hyperalgesia, accompanied by the increase of spinal p-MAPKs and c-Fos expression. Immunofluorescence staining revealed that p-MAPKs colocalized with the neuronal marker (neuronal nuclei) and the astrocyte marker (glial fibrillary acidic protein). Inhibition of MAPKs prevented and reversed pain behaviors and the increase of spinal c-Fos expression induced by intrathecal injection of ephrinB1-Fc. Inhibition of EphBs receptors by intrathecal injection of EphB1-Fc reduced formalin-induced inflammation and chronic constrictive injury-induced neuropathic pain behaviors accompanied by decreased expression of spinal p-MAPKs and c-Fos protein. Furthermore, pretreatment with MK-801, an N-methyl-d-aspartate receptor antagonist, prevented behavioral hyperalgesia and activation of spinal MAPKs induced by intrathecal injection of ephrinB1-Fc. CONCLUSIONS: These results demonstrated that activation of MAPKs contributed to modulation of spinal nociceptive information related to ephrinBs/EphBs.
Assuntos
Efrina-B1/administração & dosagem , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Dor/enzimologia , Receptores da Família Eph/fisiologia , Animais , Butadienos/administração & dosagem , Efrina-B1/toxicidade , Hiperalgesia/induzido quimicamente , Hiperalgesia/enzimologia , Hiperalgesia/patologia , Mediadores da Inflamação/administração & dosagem , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/fisiologia , Mediadores da Inflamação/toxicidade , Injeções Espinhais , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Nitrilas/administração & dosagem , Dor/induzido quimicamente , Dor/patologia , Medição da Dor/métodosRESUMO
To observe the expression of drebrin in the distal cerebrospinal fluid contacting neurons (dCSF-CNs) of rats with chronic constriction injury (CCI) of sciatic nerve by immunofluorescence technique, male Sprague-Dawley rats were randomly divided into three groups: control group, sham surgery group and CCI group. The behavior of rats was scored. After choleratoxin subunit B-conjugated horseradish peroxidase (CB-HRP, 3 muL) was injected into the lateral cerebroventricle to trace dCSF-CNs, the expression of drebrin was observed in the dCSF-CNs through immunofluorescence double staining and laser scanning confocal microscopy technique. The results showed that only the pain threshold of CCI group was decreased. The dCSF-CNs were clearly displayed in three groups. No drebrin expression was observed in the control and sham groups. In CCI group, drebrin was markedly expressed in intracytoplasm. It is suggested that the technique displaying dCSF-CNs with immunofluorescence is successful and the dCSF-CNs are possibly involved in the transmission of nociceptive information under the neuropathic pain state.
Assuntos
Neurônios/metabolismo , Neuropeptídeos/metabolismo , Nervo Isquiático/lesões , Animais , Líquido Cefalorraquidiano , Constrição Patológica , Masculino , Neuralgia/metabolismo , Limiar da Dor , Ratos , Ratos Sprague-DawleyRESUMO
Xueyu Cave watershed is located in Fengdu County in the outskirts of Chongqing, where rainfall events were monitored continuously from July 2015 to December 2017. We explored the variation of mass concentration of atmospheric dissolved inorganic nitrogen (NH4+-N and NO3--N), and quantitatively calculated its wet deposition fluxes, then the sources of NH4+-N and NO3--N were tracked using the Xueyu cave air mass backward trajectory model. The results showed that:â During the monitoring period, the average annual dissolved inorganic nitrogen (DIN) deposition in the watershed was 14.25 kg·(hm2·a)-1, of which NH4+-N and NO3--N were 7.72 kg·(hm2·a)-1 and 6.53 kg·(hm2·a)-1, accounting for 54% and 46% of DIN wet precipitation, respectively, and indicating that NH4+-N is the dominant species, followed by NO3--N; â¡DIN wet deposition flux and concentration showed marked seasonal changes. The DIN wet deposition flux in spring and summer was 50% higher than that in autumn and winter, while the DIN concentration of wet deposition in autumn and winter was 30% higher than those in spring and summer. â¢NH4+-N/NO3--N was between 0.29 and 2.27, and NH4+-N/NO3--N > 1 during the rainy season (April to October) and NH4+-N/NO3--N < 1 during the dry season (November to March), indicating that the main sources of DIN wet deposition results from agricultural activities in the rainy season, and urban contributions in the dry season. â£In the study area, the southeastern winds are dominant in the rainy season but southwestern winds are dominant in the dry season. These determine the sources of DIN wet deposition (agricultural or urban).
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In this research, the bacterial community compositions of underground water in a tourist and pristine cave were studied. Xueyu Cave and Shuiming Cave are tourist and pristine caves, respectively, in the same karst cave system located in Chongqing, southwest China. To understand the impact of tourism on bacterial community compositions in underground water that flows through the caves, filtered materials from water were collected, and 16S rDNA gene sequences were obtained by high-throughput sequencing. The Shuiming Cave (the pristine cave) had less diversity than Xueyu Cave (the tourist cave) based on the Shannon's diversity index according to Illumina operational taxonomic units (OTUs). Proteobacteria, represented mostly by γ-Proteobacterium and Bacteroidetes, dominated both systems. OTUs from Shuiming Cave were dominated by 38% Proteobacteria, 24% Chlorobi, and 19% Bacteroidetes. In the Xueyu Cave, OTUs from upstream samples were comprised of 62% Proteobacteria but comprised 64% in the downstream samples. In the Xueyu Cave, Bacteroidetes accounted for 11% of the total OTUs in the upstream sample and 16% in the downstream. Among the γ-Proteobacterium and Bacteroidetes, Acinetobacter, Pseudomonas spp., and Flavobacteriaceae, which are related to potentially pathogenic species, were prevalent in the Xueyu Cave, while Methylococcaceae-uncultured, Methylomonas spp., and Methylobacter, all methane-oxidizing bacteria, had high relative abundances in the Shuiming Cave. These results revealed that potentially more pathogenic bacteria are present in the stream waters from the tourist cave, which has important implications for the protection of tourist caves. The RDA analysis of the environmental factor and bacteria community in groundwater showed that the distribution of pathogenic bacteria was positively correlated with the cave air CO2, and the Spearman correlation analysis of the two environmental factors indicated that the influence of the number of tourists on the structure of the bacterial community in the groundwater was more obvious and led to the disappearance of a large number of native bacteria. We proposed that tourist caves control the number of daily tourists and that they enter in batches and increase the import and export of closed devices to avoid the cave air exchange inside and outside. In addition, it was recommended that they increase the import and export of sterilization devices to reduce tourists with bacteria and organic matter, and avoid leaving garbage in the hole to avoid cave microbial exchange inside and outside. A reduction in the fixed lighting inside caves should be required to reduce long exposure, since the tourists can bring individual source lighting.
Assuntos
Bactérias/classificação , Cavernas/microbiologia , Água Subterrânea/microbiologia , Viagem , China , RiosRESUMO
Geochemical indexes of drip water were monitored to unveil their seasonal variability and response mechanism to the external climate from March 2015 to March 2017 at four sites in Xueyu Cave, Chongqing municipality. The results showed that four drips show a significant difference in ion concentration and discharge despite all sites having simple HCO3--Ca2+ waters and being super-saturated with respect to calcite. Being subject to geochemical processes, such as bedrock dissolution, dilution, and prior calcite precipitation (PCP), the geochemistry indexes, such as Ca2+, Mg2+, HCO3-, EC, pH, pCO2, and SIc, at the four sites showed extraordinary seasonal variations and could perfectly respond to external climate events. Due to the difference of migration pathways and PCP intension, different types of drip water had diverse seasonal variations in Mg/Ca. Affected by soil CO2 content and hydrodynamic conditions, the δ13CDIC of all sites had correlations with external temperature or precipitation. On a short time scale, the δ13CDIC values reflected the precipitation amount in the site with its flow path controlled by conduit flow.
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Microbial contamination in karst groundwater continually increases and tracing the source researches has become a hot topic for international researchers. In this study, Laolongdong underground river at Nanshan, Chongqing was chosen as an example to adopt filter membrane methods to monitor the fecal microbial contaminations including the total bacterial concentration (TB), the total E. coli concentration (TE), the total fecal coliform (FC) and the total fecal Streptocoocci (FS). Bacteriodes was used as an indicator and PCR-DGGE analysis was used to trace fecal contamination sources in karst groundwater. The results suggested that groundwater in this area was seriously polluted by microbes from feces. The concentrations of microbial parameters exceeded limited levels greatly and the total bacterial amounts ranged 10-2.9 x 107 CFU · mL⻹, the concentrations of E. coli were between 4.3-4.0 x 105 CFU · mL⻹, the max concentration of FC was 1.1 x 106 CFU · (100 mL)⻹ and the max concentration of FS was 1.1 x 105 CFU · (100 mL)⻹. The FC/FS ratios were mostly over 2 which suggested that the main fecal source in groundwater was human feces. In addition, PCR-DGGE contrastive analysis of Bacteroides communities showed that the similarities between groundwater samples and human feces were in range of 7. 1% -69. 1% , and the similarity of the groundwater sample from Laolongdong underground river outlet was 69.1% . Bacteroides community similarities between groundwater samples and swine feces were in range of 1.1%-53.4%, and the similarity of Laolongdong underground river outlet was merely 1.5%. The similarity data implied that groundwater contamination resulted mainly from human feces, swine feces contamination composed part of animals' fecal contamination, and other animals' feces participated too. Furthermore, sequencing results of PCR-DGGE products revealed that most Bacteroides in groundwater originated from human intestinal tract and human feces.
Assuntos
Bacteroides/isolamento & purificação , Monitoramento Ambiental , Fezes/microbiologia , Água Subterrânea/microbiologia , Rios/microbiologia , Animais , China , Escherichia coli/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , SuínosRESUMO
To analyze the influencing factors of karstification and karst carbon cycle, a simulation experiment was carried out and 6 soil columns were designed. The results showed that the content of H2O4, hydrodynamic condition and thickness of the soil had important influence on karstification and karst carbon cycle. For the soil columns which were covered by the same thickness of soil, the concentrations of Ca2+ + Mg2+ and SO4(2-) followed the order of B20-2 > B20-1 > B20-3, B50-2 > B50-1 > B50-3. This meant that input of H2SO4 enhanced the karstification and increasing infiltration water had significant dilution effect on the chemical properties. For the soil columns with different thickness of soil but with the same slag pile and hydrodynamic conditions, the concentrations of Ca2+ + Mg2+ and SO4(2-) followed the order of B50-1 > B20-1, B50-2 > B20-2, B50-3 > B20-3. It was demonstrated that more carbonate rock was dissolved under the thick soil columns. In addition, the net consumption of CO2 mainly depended on the content of H2SO4 in this experiment due to slight contribution of H2CO3 to carbonate rock dissolution. More content of H2SO4 brought about less net consumption of C02, but B50-2 was an exception. Organic matter and other nutrients might be input into deep soil with the slag pile, and they promoted the production of soil C)2. Therefore, more CO2 was consumed due to the increased contribution of H2CO to karstification.
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Ciclo do Carbono , Solo/química , Carbono , Carbonatos , Modelos Teóricos , ÁguaRESUMO
To gain more knowledge on the change of karst spring and its influencing factors, the hydrochemistry and δ13CDIC of Baishuwan spring, Lanhuagou spring and Hougou spring were monitored in rainy season (from June 2014 to October 2014) and contrasted with the results obtained in dry season. The results showed that more carbonate rock was dissolved and less CO2 was consumed in rainy season. And for Lanhuagou spring and Hougou spring, the CO2 consumption was less than the production. Compared to other months in rainy season, the least carbonate rock dissolution and the most CO2 consumption were observed in July 2014. Influenced by hydrodynamic condition, carbonate rock dissolved by HNO3 and H2SO4 increased while that dissolved by H2CO3 decreased during the rainy season. The δ13CDIC increased due to the HNO3 and H2SO4 dissolution of carbonate rock and the dehydration of HCO3-. Therefore, δ13CDIC correlated negatively to HCO3- concentration and positively to NO3- + SO(4)2- concentration. It was indicated that the hydrochemistry and δ13CDIC of karst springs were affected by the HNO3, H2SO4 and hydrodynamic condition.
Assuntos
Isótopos de Carbono/análise , Carbonatos/análise , Monitoramento Ambiental , Nascentes Naturais/química , Dióxido de Carbono/análise , Chuva , Estações do AnoRESUMO
The brainstem is well recognized as a critical site for integrating descending modulatory systems that both inhibit and facilitate pain at the level of the spinal cord. The cerebrospinal fluid-contacting nucleus (CSF-contacting nucleus) distributes and localizes in the ventral periaqueductal central gray of the brainstem. Although emerging lines of evidence suggest that the CSF-contacting nucleus may be closely linked to transduction and regulation of pain signals, the definitive role of the CSF-contacting nucleus in pain modulation remains poorly understood. In the present study, we determined the role of the CSF-contacting nucleus in rat nocifensive behaviors after persistent pain by targeted ablation of the CSF-contacting nucleus in the brainstem using the cholera toxin subunit B-saporin (CB-SAP), a cytotoxin coupled to cholera toxin subunit B. Compared with CB/SAP, CB-SAP induced complete ablation of the CSF-contacting nucleus, and the CB-SAP-treated rats showed hypersensitivity in responses to acute nociceptive stimulation, and exacerbated spontaneous nocifensive responses induced by formalin, thermal hyperalgesia and mechanical allodynia induced by plantar incision. Furthermore, immunohistochemical experiments showed that the CSF-contacting nucleus was a cluster of 5-HT-containing neurons in the brainstem, and the spinal projection of serotonergic axons originating from the CSF-contacting nucleus constituted the descending 5-HT pathway to the spinal cord. CB-SAP induced significant downregulation of 5-HT in the spinal dorsal horn, and intrathecal injection of 5-HT significantly reversed hypersensitivity in responses to acute nociceptive stimulation in the CB-SAP-treated rats. These results indicate that the CSF-contacting nucleus 5-HT pathway is an important component of the endogenous descending inhibitory system in the control of spinal nociceptive transmission.
Assuntos
Tronco Encefálico/patologia , Líquido Cefalorraquidiano , Dor/patologia , Transdução de Sinais , Medula Espinal/patologia , Animais , Toxina da Cólera , Modelos Animais de Doenças , Formaldeído/toxicidade , Frequência Cardíaca/efeitos dos fármacos , Masculino , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Vias Neurais/metabolismo , Vias Neurais/fisiopatologia , Dor/etiologia , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Ratos , Ratos Sprague-Dawley , Respiração/efeitos dos fármacos , Proteínas Inativadoras de Ribossomos Tipo 1 , Saporinas , Serotonina/farmacologiaRESUMO
To optimize a technique that induces bone marrow mesenchymal stem cells (BMSCs) to differentiation into neural-like cells, using cerebrospinal fluid (CSF) from the patient. In vitro, CSF (Group A) and the cell growth factors EGF and bFGF (Group B) were used to induce BMSCs to differentiate into neural-like cells. Post-induction, presence of neural-like cells was confirmed through the use of light and immunofluorescence microscopy. BMSCs can be induced to differentiate into neural-like cells. The presence of neural-like cells was confirmed via morphological characteristics, phenotype, and biological properties. Induction using CSF can shorten the production time of neural-like cells and the quantity is significantly higher than that obtained by induction with growth factor (P < 0.01). The two induction methods can induce BMSCs to differentiate into neural-like cells. Using CSF induction, 30 ml bone marrow can produce a sufficient number of neural-like cells that totally meet the requirements for clinical treatment.
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Células da Medula Óssea/citologia , Diferenciação Celular , Líquido Cefalorraquidiano , Células-Tronco Mesenquimais/citologia , Neurônios/citologia , Contagem de Células , Técnicas de Cultura de Células , Humanos , Valores de ReferênciaRESUMO
The activation of mitogen-activated protein kinases (MAPKs) has been observed in synaptic plasticity processes of learning and memory in morphine dependence. However, the role of extracellular signal-regulated protein kinase 5 (ERK5), a member of MAPKs, has not been studied yet in morphine dependence. To identify the function of ERK5 in the formation and development of morphine physical dependence, morphine withdrawal-like behavioral test and western blot technique were used in this research. Morphine was subcutaneously injected by an intermittent and escalating procedure to induce physical dependence, which was measured by withdrawal symptoms. In this study, spinal ERK5 signaling pathway was remarkably activated by chronic morphine injection and naloxone-precipitated withdrawal. Intrathecal injection of BIX02188, a novel specific inhibitor of mitogen-activated protein kinases kinase 5 (MEK5), produced a dose- and time-dependent inhibition of the activation of spinal ERK5, without affecting activation of other MAPKs. Moreover, selective attenuation of spinal p-ERK5 expression by BIX02188 could significantly relieve morphine withdrawal symptom, accompanying with the decreased phosphorylation of cAMP response-element binding protein (CREB) in the spinal cord. These findings suggested that activation of the ERK5 signaling pathway might contribute to morphine physical dependence and its specific pharmacological inhibitor BIX02188 could be a potential therapeutic choice for alleviation of morphine withdrawal symptoms in the future.
Assuntos
Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Dependência de Morfina/metabolismo , Morfina/administração & dosagem , Transdução de Sinais/fisiologia , Medula Espinal/metabolismo , Análise de Variância , Compostos de Anilina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Western Blotting , Relação Dose-Resposta a Droga , Indóis/farmacologia , Distribuição Aleatória , Ratos , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacosRESUMO
The cerebrospinal fluid-contacting nucleus (CSF-CN), distributes and localizes in the ventral periaqueductal central gray (PAG) of the brainstem, which may influence actual composition of the cerebrospinal fluid (CSF) for non-synaptic signal transmission via releasing or absorbing bioactive substances. Many experiments have demonstrated that substance P (SP), a substance that is shown to be up-regulated in CSF-CN, plays an important role in the development of inflammatory pain and neuropathic pain. Thus in the present study, we hypothesize that SP in CSF-CN might contribute to morphine dependence in rats, inhibiting SP with (D-Pro2, D-Phe7, D-Trp9)-SP intracerebroventricular (i.c.v.) injection reduce chronic morphine dependence and withdrawal. Rats were repeatedly injected with morphine in five escalating doses for morphine physical dependence. Morphine withdrawal-like behavioral signs and morphine analgesia behaviors were monitored after naloxone administration following i.c.v. injection of (D-Pro2, D-Phe7, D-Trp9)-SP. And SP-expression of CSF-CN was evaluated with dual-label immunofluorescent technique on morphine withdrawal in rats. After i.c.v. treatment with (D-Pro2, D-Phe7, D-Trp9)-SP, the naloxone-precipitated withdrawal symptoms were significantly attenuated, paw withdrawal threshold/thermal withdrawal latency (PWT/TWL) were increased, and SP-expression in CSF-CN was significantly reduced than control group. SP, known a neurotransmitter/neuromodulator of nociception, has also been implicated in the signs of opioid withdrawal. This study provides the first evidence that SP in CSF-CN contributes to morphine physical dependence and withdrawal, which may provide an important and specific role in mediating the motivational aspects of opiates withdrawal via CSF - the parenchyma of the brain, and may represent a novel pharmacological route such as SP inhibitor i.c.v. injection for the control of drug abuse.
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Dependência de Morfina/metabolismo , Substância Cinzenta Periaquedutal/metabolismo , Substância P/metabolismo , Animais , Imunofluorescência , Masculino , Dependência de Morfina/fisiopatologia , Substância Cinzenta Periaquedutal/química , Ratos , Ratos Sprague-DawleyRESUMO
Recent studies have shown that general anesthesia induces memory impairment. Sevoflurane, an inhalation anesthetic, is widely used in clinical practice, increasing pieces of evidence suggest that sevoflurane impairs memory processes due to changing gene expression in hippocampus. However, little is known about genome-widely analyzing the expression change induced by sevoflurane in hippocampus. In this study, we profiled the changes of hippocampal gene expression by microarray analysis. Six-week-old male Sprague-Dawley rats were anesthetized for 4h with 2.5% sevoflurane (n = 6) and were sacrificed 48 h later. RNA was extracted from the hippocampus for gene expression profile. Compared to control group, 417 genes, including up-regulated 67 and down-regulated 350, were significantly changed (> 2.0 or < -2.0 fold) (P < 0.05). Of these, there are 45 named genes, which are most involved in metabolism, development, biosynthesis, life material binding, location, signal transduction and communication, structural and vesicular processes. We randomly chose 6 differential genes to verify the microarray result. We also selected seven most differential genes, including 3 up-regulated genes (RMCP-1, Slc6a3, and Pitx2) and 4 down-regulated genes (VN7, AVP, IP10, and OT), to investigate whether there is a dose- or time-dependent effect of sevoflurane on gene expression. The result indicated that the microarray profile is reliable; there is no obvious dose-dependent effect of sevoflurane on gene expression. These results suggested that sevoflurane induced long-term (at least 2 days) expression change of the numerous genes in hippocampus, which may be related to the memory impairment or the other neural disorders.
Assuntos
Anestésicos Inalatórios/farmacologia , Perfilação da Expressão Gênica , Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Éteres Metílicos/farmacologia , Animais , Relação Dose-Resposta a Droga , Hipocampo/metabolismo , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SevofluranoRESUMO
BACKGROUND: Previous studies have demonstrated that QX-314, an intracellular sodium channel blocker, can enter into nociceptors through capsaicin-activated TRPV1 or permeation of the membrane by chemical enhancers to produce a sensory-selective blockade. However, the obvious side effects of these combinations limit the application of QX-314. A new strategy for targeting delivery of QX-314 into nociceptors needs further investigation. The aim of this study is to test whether acidic QX-314, when dissolves in acidic solution directly, can enter into nociceptors through acid-activated TRPV1 and block sodium channels from the intracellular side to produce a sensory-specific analgesic effect. METHODOLOGY/PRINCIPAL FINDINGS: Acidic solution or noradrenaline was injected intraplantarly to induce acute pain behavior in mice. A chronic constrictive injury model was performed to induce chronic neuropathic pain. A sciatic nerve blockade model was used to evaluate the sensory-specific analgesic effects of acidic QX-314. Thermal and mechanical hyperalgesia were measured by using radiant heat and electronic von Frey filaments test. Spinal Fos protein expression was determined by immunohistochemistry. The expression of p-ERK was detected by western blot assay. Whole cell clamp recording was performed to measure action potentials and total sodium current in rats DRG neurons. We found that pH 5.0 PBS solution induced behavioral hyperalgesia accompanied with the increased expression of spinal Fos protein and p-ERK. Pretreatment with pH 5.0 QX-314, and not pH 7.4 QX-314, alleviated pain behavior, inhibited the increased spinal Fos protein and p-ERK expression induced by pH 5.0 PBS or norepinephrine, blocked sodium currents and abolished the production of action potentials evoked by current injection. The above effects were prevented by TRPV1 channel inhibitor SB366791, but not by ASIC channel inhibitor amiloride. Furthermore, acidic QX-314 employed adjacent to the sciatic nerve selectively blocked the sensory but not the motor functions in naïve and CCI mice. CONCLUSIONS/SIGNIFICANCE: Acid solution is a suitable medium for introducing QX-314 into nociceptors through TRPV1 channels to produce a sensory-specific analgesic effect.
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Ácidos/química , Analgésicos/farmacologia , Lidocaína/análogos & derivados , Nociceptores/efeitos dos fármacos , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Cátion TRPV/metabolismo , Animais , Western Blotting , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Imuno-Histoquímica , Lidocaína/farmacologia , Masculino , Camundongos , Técnicas de Patch-Clamp , Ratos Sprague-Dawley , SoluçõesRESUMO
EphBs receptors and their ephrinBs ligands are present in the adult brain and peripheral tissue and play a critical role in modulating multiple aspects of physiology and pathophysiology. Our recent evidence has shown that ephrinBs acted as a sensitizer to participate in peripheral sensitization and hyperalgesia induced by activation of peripheral ephrinBs/EphBs signaling. In the present study, we explored the role of phosphatidylinositol 3-kinase (PI3K) in ephrinB1-Fc-induced pain behaviors. Intraplantar injection of ephrinB1-Fc produced a time- and dose-dependent increase of PI3K-p110gamma expression and of phosphorylation of AKT in skin of injection site. Pre-treatment with PI3K inhibitor wortmannin or LY294002 prevented activation of peripheral AKT by ephrinB1-Fc. The activated AKT expressed in peripheral nerve terminals and DRG peptide-containing and small non-peptide-containing neurons. Inhibition of peripheral PI3K signaling dose-dependently prevented and reversed pain behaviors and spinal Fos protein expression induced by intraplantar injection of ephrinB1-Fc. Furthermore, pre-treatment with PI3K inhibitor wortmannin or LY294002 prevented ephrinB1-Fc-induced ERK activation in a dose-dependent manner. These data demonstrated that PI3K and PI3K crosstalk to ERK signaling mediated pain behaviors induced by activation of peripheral ephrinBs/EphBs signaling in mice.