Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 202
Filtrar
1.
Nitric Oxide ; 147: 1-5, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38547960

RESUMO

Endotoxin tolerance (ET) is the hyporesponsiveness to lipopolysaccharide (LPS) after prior exposure. It is characterized by the downregulation of pro-inflammatory cytokine levels. Although ET protects against inflammation, its abolishment or recovery is critical for immunity. Nitric oxide (NO) plays various roles in the development of ET; however, its specific role in ET recovery remains unknown. To induce ET, RAW264.7 cells (a murine macrophage cell line) were pre-exposed to LPS (LPS1, 100 ng/mL for 24 h) and subsequently re-stimulated with LPS (LPS2, 100 ng/mL for 24 h). Expression of cytokines, NO, nitrite and inducible NO synthase (iNOS) were measured after 0, 12, 24, and 36 h of resting after LPS1 treatment with or without the iNOS-specific inhibitor, 1400W. LPS2-induced tumor necrosis factor-⍺ (TNF-⍺) and interleukin-6 (IL-6) were downregulated after LPS1 treatment, confirming the development of ET. Notably, TNF-⍺ and IL-6 levels spontaneously rebounded after 12-24 h of resting following LPS1 treatment. In contrast, levles of NO, nitrite and iNOS increased during ET development and decreased during ET recovery. Moreover, 1400W inhibited ET development and blocked the early production of NO (<12 h) during ET recovery. Our findings suggest a negative correlation between iNOS-induced NO and cytokine levels in the abolishment of ET.


Assuntos
Lipopolissacarídeos , Óxido Nítrico Sintase Tipo II , Óxido Nítrico , Fator de Necrose Tumoral alfa , Animais , Óxido Nítrico/metabolismo , Camundongos , Lipopolissacarídeos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , Interleucina-6/metabolismo , Endotoxinas/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo
2.
Curr Microbiol ; 81(10): 328, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39186081

RESUMO

A polyphasic taxonomic approach was used to characterize a novel bacterium, designated strain CC-CFT758T, isolated from a maize-rice rotation agriculture field in Taiwan. The cells are aerobic, Gram-stain-negative, rod-shaped, positive for catalase and oxidase, and grow at 20-30 °C (optimal 30 â„ƒ), at pH 6.0-8.0 (optimal 8.0), and with 0-4% (w/v) NaCl (optimum, 2-3%). Phylogenetic analysis based on 16S rRNA gene sequencing, the strain CC-CFT758T belongs to the genus "Aliirhizobium" of the family Rhizobiaceae. The closest known relatives of this strain are "Aliirhizobium wenxiniae" 166T (with 98.7% similarity), "Aliirhizobium cellulosilyticum" SEMIA 448T (with 97.9% similarity), and "Aliirhizobium smilacinae" PTYR-5T (with 97.0% similarity). The genome size was 5.9 Mbp, with a G + C content of 60.6%. Values of digital DNA-DNA hybridization between the strain and closely related species were 29.5% for "Ali. cellulosilyticum", and 23.9% for "Ali. wenxiniae" and "Ali. smilacinae". Strain CC-CFT758T exhibited the highest orthologous average nucleotide identity (OrthoANI) values with members of the genus "Aliirhizobium", ranging from 80.4 to 81.6% (n = 3). Chemotaxonomical analysis indicated that strain CC-CFT758T contained C16:0, C16:0 3OH, C19:0 cyclo ω8c, C14:0 3OH/iso-C16:1 I, and C18:2 ω6,9c/ante C18:0 as dominant fatty acids, and the major polyamines were putrescine and spermidine. The polar lipids comprised diphosphatidylglycerol, phosphatidylcholin, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, seven unidentified aminolipids, three unidentified phospholipids, and two unidentified polar lipids. Strain CC-CFT758T exhibited distinct phylogenetic, phenotypic, and chemotaxonomic characteristics, as well as unique results in comparative analysis of 16S rRNA gene sequence, OrthoANI, AAI, dDDH, and phylogenomic placement. Therefore, this strain represents a new species of the genus "Aliirhizobium", for which the name Aliirhizobium terrae sp. nov. is proposed, with the type strain is CC-CFT758T (= BCRC 81364T = JCM 35482T).


Assuntos
Composição de Bases , DNA Bacteriano , Ácidos Graxos , Oryza , Filogenia , RNA Ribossômico 16S , Zea mays , Zea mays/microbiologia , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Oryza/microbiologia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Hibridização de Ácido Nucleico , Taiwan , Agricultura , Análise de Sequência de DNA , Fosfolipídeos/análise
3.
Int J Mol Sci ; 25(16)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39201534

RESUMO

The purpose of this study was to investigate whether and how albiflorin, a natural monoterpene glycoside, affects the release of glutamate, one of the most important neurotransmitters involved in neurotoxicity, from cerebrocortical nerve terminals (synaptosomes) in rats. The results showed that albiflorin reduced 4-aminopyridine (4-AP)-elicited glutamate release from synaptosomes, which was abrogated in the absence of extracellular Ca2+ or in the presence of the vesicular glutamate transporter inhibitor or a P/Q-type Ca2+ channel inhibitor, indicating a mechanism of action involving Ca2+-dependent depression of vesicular exocytotic glutamate release. Albiflorin failed to alter the increase in the fluorescence intensity of 3,3-diethylthiacarbocyanine iodide (DiSC3(5)), a membrane-potential-sensitive dye. In addition, the suppression of protein kinase A (PKA) abolished the effect of albiflorin on glutamate release. Albiflorin also reduced the phosphorylation of PKA and synaptosomal-associated protein of 25 kDa (SNAP-25) and synapsin I at PKA-specific residues, which correlated with decreased available synaptic vesicles. The results of transmission electron microscopy (TEM) also observed that albiflorin reduces the release competence of synaptic vesicles evoked by 4-AP in synaptosomes. In conclusion, by studying synaptosomally released glutamate, we suggested that albiflorin reduces vesicular exocytotic glutamate release by decreasing extracellular Ca2+ entry via P/Q-type Ca2+ channels and reducing PKA-mediated synapsin I and SNAP-25 phosphorylation.


Assuntos
Córtex Cerebral , Proteínas Quinases Dependentes de AMP Cíclico , Ácido Glutâmico , Sinaptossomos , Animais , Ácido Glutâmico/metabolismo , Sinaptossomos/metabolismo , Sinaptossomos/efeitos dos fármacos , Ratos , Córtex Cerebral/metabolismo , Córtex Cerebral/efeitos dos fármacos , Masculino , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Canais de Cálcio Tipo Q/metabolismo , Ratos Sprague-Dawley , Canais de Cálcio Tipo P/metabolismo , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Cálcio/metabolismo , Fosforilação/efeitos dos fármacos , Sinapsinas/metabolismo
4.
Geriatr Nurs ; 56: 321-327, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38422627

RESUMO

AIM(S): To investigate the factorial structure, test-retest reliability, and internal consistency of the Older Volunteer Competency Scale and establish its psychometric properties. DESIGN: Cross-sectional survey. METHODS: A total of 1,000 older volunteers were recruited through random sampling and asked to complete the Older Volunteer Competency Scale. Subsequently, 100 participants were selected to participate in a second test to determine the scale's test-retest reliability. Factorial structure was assessed through exploratory factor analysis and confirmatory factor analysis, and internal consistency was assessed using Cronbach's α. RESULTS: Favorable exploratory and confirmatory factor analysis results were obtained. In addition, the three dimensions of the Older Volunteer Competency Scale, namely service awareness, service skills, and interpersonal interaction, had high internal consistency and test-retest reliability. CONCLUSION: The Older Volunteer Competency Scale is an effective and reliable research instrument for evaluating competency and needs among older volunteers.


Assuntos
Projetos de Pesquisa , Humanos , Inquéritos e Questionários , Estudos Transversais , Psicometria/métodos , Reprodutibilidade dos Testes
5.
J Gerontol Soc Work ; 67(8): 1211-1226, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38922327

RESUMO

The present survey research investigated older people's volunteering competency relating to social inequality by exploring the latent ability profile and demographic correlates of 1,000 older volunteers in 73 community care centersin southern Taiwan. Older volunteers were classified into advanced (n = 509), basic (n = 214), and novice (n = 277) groups. Demographics examined included: individualistic characteristics (religious beliefs), resources (education; number of chronic diseases), andsocial factors (serving area and spoken language, volunteering duration, marital status, and gender). Apparent inequality issues were revealed. The advanced group was better educated, Mandarin-speaking, and in urban areas. while the novice group featured the opposite (lower education Taiwanese-speaking suburban areas).


Assuntos
Voluntários , Humanos , Voluntários/psicologia , Masculino , Feminino , Idoso , Taiwan , Idoso de 80 Anos ou mais , Fatores Socioeconômicos , Fatores Sociodemográficos
6.
Small ; : e2308676, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072780

RESUMO

Highly emissive semiconductor nanocrystals, or so-called quantum dots (QDs) possess a variety of applications from displays and biology labeling, to quantum communication and modern security. Though ensembles of QDs have already shown very high photoluminescent quantum yields (PLQYs) and have been widely utilized in current optoelectronic products, QDs that exhibit high absorption cross-section, high emission intensity, and, most important, nonblinking behavior at single-dot level have long been desired and not yet realized at room temperature. In this work, infrared-emissive MAPbI3 -based halide perovskite QDs is demonstrated. These QDs not only show a ≈100% PLQY at the ensemble level but also, surprisingly, at the single-dot level, display an extra-large absorption cross-section up to 1.80 × 10-12 cm2 and non-blinking single photon emission with a high single photon purity of 95.3%, a unique property that is extremely rare among all types of quantum emitters operated at room temperature. An in-depth analysis indicates that neither trion formation nor band-edge carrier trapping is observed in MAPbI3 QDs, resulting in the suppression of intensity blinking and lifetime blinking. Fluence-dependent transient absorption measurements reveal that the coexistence of non-blinking behavior and high single photon purity in these perovskite QDs results from a significant repulsive exciton-exciton interaction, which suppresses the formation of biexciton, and thus greatly reduces photocharging. The robustness of these QDs is confirmed by their excellent stability under continuous 1 h electron irradiation in high-resolution transmission electron microscope inspection. It is believed that these results mark an important milestone in realizing nonblinking single photon emission in semiconductor QDs.

7.
Int J Syst Evol Microbiol ; 73(11)2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37962187

RESUMO

A polyphasic taxonomic approach was used to characterize a novel bacterium, designated strain CC-YST667T, isolated from poultry manure sampled in Taiwan. The cells were observed to be aerobic, motile and non-spore-forming rods, displaying positive reactions for oxidase. Optimal growth of CC-YST667T was observed at 25 °C, pH 8.0 and with 1 % (w/v) NaCl. The polar lipid profile consisted of phosphatidylmonomethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and multiple unidentified polar lipids. The major polyamine was spermidine. The major cellular fatty acids (>5 %) included C16 : 0, C17 : 0cyclo, C19 : 0cyclo ω8c and C14 : 0 3OH/iso-C16 : 1 I. On the basis of the results of analysis of 16S rRNA gene sequences, this isolate showed the closest phylogenetic relationship with 'Neopusillimonas minor' (with 98.2 % similarity) and Paralcaligenes ureilyticus (with 97.3 % similarity) of the family Alcaligenaceae. The draft genome, (3.3 Mb) with a DNA G+C content of 57.2 mol%, harboured various genes involved in the biodegradation of aromatic hydrocarbons. CC-YST667T shared highest orthologous average nucleotide identity (OrthoANI) with the type strains of species of of the genera Neopusillimonas (72.4‒77.9 %, n=2), Pusillimonas (72.8‒73.0 %, n=2) and Pollutimonas (71.7‒73.0 %, n=5). On the basis of its distinct phylogenetic, phenotypic and chemotaxonomic traits together with the results of comparative 16S rRNA gene sequencing, OrthoANI, digital DNA-DNA hybridization (DDH) and the phylogenomic placement, strain CC-YST667T is considered to represent a novel species of the genus Neopusillimonas, for which the name Neopusillimonas aromaticivorans sp. nov. is proposed. The type strain is CC-YST667T (=BCRC 81321T =JCM 34761T).


Assuntos
Ácidos Graxos , Fosfolipídeos , Animais , Ácidos Graxos/química , Fosfolipídeos/química , Esterco , Filogenia , RNA Ribossômico 16S/genética , Aves Domésticas , Análise de Sequência de DNA , Composição de Bases , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética
8.
Int J Mol Sci ; 24(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36674576

RESUMO

We attempted to examine the alterations elicited by opioids via coexpressed µ-opioid (MOP) and nociceptin/orphanin FQ (NOP) receptors for receptor localization and Erk1/2 (p44/42 MAPK) in human embryonic kidney (HEK) 293 cells. Through two-photon microscopy, the proximity of MOP and NOP receptors was verified by fluorescence resonance energy transfer (FRET), and morphine but not buprenorphine facilitated the process of MOP-NOP heterodimerization. Single-particle tracking (SPT) further revealed that morphine or buprenorphine hindered the movement of the MOP-NOP heterodimers. After exposure to morphine or buprenorphine, receptor localization on lipid rafts was detected by immunocytochemistry, and phosphorylation of Erk1/2 was determined by immunoblotting in HEK 293 cells expressing MOP, NOP, or MOP+NOP receptors. Colocalization of MOP and NOP on lipid rafts was enhanced by morphine but not buprenorphine. Morphine stimulated the phosphorylation of Erk1/2 with a similar potency in HEK 293 cells expressing MOP and MOP+NOP receptors, but buprenorphine appeared to activate Erk1/2 solely through NOP receptors. Our results suggest that opioids can fine-tune the cellular localization of opioid receptors and phosphorylation of Erk1/2 in MOP+NOP-expressing cells.


Assuntos
Buprenorfina , Receptores Opioides , Humanos , Receptores Opioides/metabolismo , Receptor de Nociceptina , Analgésicos Opioides/farmacologia , Células HEK293 , Fosforilação , Receptores Opioides mu/metabolismo , Buprenorfina/farmacologia , Morfina/farmacologia
9.
Molecules ; 28(3)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36770979

RESUMO

Inhibiting the excessive release of glutamate in the brain is emerging as a promising therapeutic option and is efficient for treating neurodegenerative disorders. The aim of this study is to investigate the effect and mechanism of plantainoside D (PD), a phenylenthanoid glycoside isolated from Plantago asiatica L., on glutamate release in rat cerebral cortical nerve terminals (synaptosomes). We observed that PD inhibited the potassium channel blocker 4-aminopyridine (4-AP)-evoked release of glutamate and elevated concentration of cytosolic Ca2+. Using bafilomycin A1 to block glutamate uptake into synaptic vesicles and EDTA to chelate extracellular Ca2+, the inhibitory effect of PD on 4-AP-evoked glutamate release was prevented. In contrast, the action of PD on the 4-AP-evoked release of glutamate in the presence of dl-TBOA, a potent nontransportable inhibitor of glutamate transporters, was unaffected. PD does not alter the 4-AP-mediated depolarization of the synaptosomal membrane potential, suggesting that the inhibitory effect of PD on glutamate release is associated with voltage-dependent Ca2+ channels (VDCCs) but not the modulation of plasma membrane potential. Pretreatment with the Ca2+ channel blocker (N-type) ω-conotoxin GVIA abolished the inhibitory effect of PD on the evoked glutamate release, as did pretreatment with the protein kinase C inhibitor GF109203x. However, the PD-mediated inhibition of glutamate release was eliminated by applying the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157 or dantrolene, which inhibits Ca2+ release through ryanodine receptor channels. These data suggest that PD mediates the inhibition of evoked glutamate release from synaptosomes primarily by reducing the influx of Ca2+ through N-type Ca2+ channels, subsequently reducing the protein kinase C cascade.


Assuntos
4-Aminopiridina , Ácido Glutâmico , Ratos , Animais , Ácido Glutâmico/metabolismo , Ratos Sprague-Dawley , 4-Aminopiridina/farmacologia , Sinaptossomos/metabolismo , Sinalização do Cálcio , Proteína Quinase C/metabolismo , Córtex Cerebral/metabolismo , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia
10.
J Cell Physiol ; 237(1): 178-188, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34406646

RESUMO

Dysregulation of DNA damage response/repair and genomic instability promote tumorigenesis and the development of various neurological diseases. Autophagy is a dynamic catabolic process used for removing unnecessary or dysfunctional proteins and organelles in cells. Despite the consensus in the field that upregulation of autophagy promotes the initiation of the DNA damage response and assists the process of homologous recombination upon genotoxic stress, a few studies showed that upregulation of autophagy (or excessive autophagy), under certain circumstances, triggers caspase/apoptosis-independent DNA damage and promotes genomic instability in cells. As the cytoprotective and the DNA repairing roles of autophagy have been discussed extensively in different reviews, here, we mainly focus on describing the latest studies which reported the "opposite" roles of autophagy (or excessive autophagy). We will discuss whether the "dark side" (i.e., the opposite/unconventional effect) of autophagy on the maintenance of DNA integrity and genomic stability really does exist in cells and if it does, will it be one of the yet-to-be-identified causes of cancer, in this review.


Assuntos
Autofagia , Instabilidade Genômica , Autofagia/genética , Carcinogênese/metabolismo , Dano ao DNA/genética , Reparo do DNA , Instabilidade Genômica/genética , Humanos
11.
Environ Microbiol ; 24(12): 6112-6127, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36222141

RESUMO

Saline springs within the Illinois Basin result from the discharge of deep-seated evaporated seawater (brine) and likely contain diverse and complex microbial communities that are poorly understood. In this study, seven saline/mineral springs with different geochemical characteristics and salinity origins were investigated using geochemical and molecular microbiological analyses to reveal the composition of microbial communities inhabiting springs and their key controlling factors. The 16S rRNA sequencing results demonstrated that each spring harbours a unique microbial community influenced by its geochemical properties and subsurface conditions. The microbial communities in springs that originated from Cambrian/Ordovician strata, which are deep confined units that have limited recharge from overlying formations, share a greater similarity in community composition and have a higher species richness and more overlapped taxa than those that originated from shallower Pennsylvanian strata, which are subject to extensive regional surface and groundwater recharge. The microbial distribution along the spring flow paths at the surface indicates that 59.8%-94.2% of total sequences in sedimentary samples originated from spring water, highlighting the role of springs in influencing microbiota in the immediate terrestrial environment. The results indicate that the springs introduce microbiota with a high biodiversity into surface terrestrial or aquatic ecosystems, potentially affecting microbial reservoirs in downstream ecosystems.


Assuntos
Água Subterrânea , Microbiota , RNA Ribossômico 16S/genética , Salinidade , Microbiota/genética , Água Subterrânea/microbiologia , Água do Mar/microbiologia
12.
Ann Plast Surg ; 88(1s Suppl 1): S114-S118, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35225858

RESUMO

ABSTRACT: Recurrent pelvic pressure injuries are common among paraplegic patients with spinal cord injury. Most of them experienced multiple surgical treatments because of recurrence. Based on the "spare part" concept, the double fillet flap is feasible when all other reconstructive procedures were exhausted. In this case report, we present the double fillet flap technique to manage recurrent extended pelvic pressure ulcers in a paraplegic spinal cord injury patient.


Assuntos
Procedimentos de Cirurgia Plástica , Úlcera por Pressão , Traumatismos da Medula Espinal , Humanos , Paraplegia/complicações , Úlcera por Pressão/etiologia , Úlcera por Pressão/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/cirurgia , Retalhos Cirúrgicos/cirurgia
13.
Ann Plast Surg ; 88(1s Suppl 1): S62-S67, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35225849

RESUMO

BACKGROUND: The most challenging complication associated with lower blepharoplasty is ectropion, and the traditional lateral canthopexy or canthoplasty procedure may carry the risk of eyelid malposition or subsequent chemosis. We propose lateral tarsoplasty with a detailed description of the techniques to treat and even prevent ectropion by not involving the medial or lateral canthal ligament so as to avoid complications. MATERIALS AND METHODS: Lower eyelid laxity was analyzed with the snap-back test and distraction test before surgery. Approximately 5 mm medial to the lateral canthus, lateral tarsoplasty is performed through a full-thickness pentagonal tarsal-conjunctival resection according to the "overlapping test" for an accurate measurement of the amount of the tarsus to be resected. Seventy-two eyelids that received either ectropion correction or prevention with lateral tarsoplasty over an 8-year period at a single institution were collected and analyzed for this retrospective review. RESULTS: Lateral tarsoplasty was performed in 39 patients with a mean age of 63.8 years. Thirteen patients with 20 eyelids presented for ectropion correction, in whom 5 to 10 mm of tarsus was resected, 6.0 mm in average. The other 26 patients with 52 eyelids presented for ectropion prevention, in whom 3 to 7 mm of tarsus was resected, 4.1 mm in average. Apart from temporary mild chemosis, all patients experienced highly satisfactory results without any ectropion or malposition of the involved lower eyelids after a follow-up of 8.1 months in average. CONCLUSIONS: For patients with moderate and severe laxity of lower eyelids, lateral tarsoplasty without involvement of the lateral canthal ligament proves to be an effective way to treat and prevent lower eyelid ectropion.


Assuntos
Blefaroplastia , Ectrópio , Procedimentos de Cirurgia Plástica , Blefaroplastia/métodos , Ectrópio/etiologia , Ectrópio/cirurgia , Pálpebras/cirurgia , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos
14.
Int J Mol Sci ; 23(5)2022 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-35269784

RESUMO

The neurotransmitter glutamate plays an essential role in excitatory neurotransmission; however, excessive amounts of glutamate lead to excitotoxicity, which is the most common pathogenic feature of numerous brain disorders. This study aimed to investigate the role of butyl 2-[2-(2-fluorophenyl)acetamido]benzoate (HFP034), a synthesized anthranilate derivative, in the central glutamatergic system. We used rat cerebro-cortical synaptosomes to examine the effect of HFP034 on glutamate release. In addition, we used a rat model of kainic acid (KA)-induced glutamate excitotoxicity to evaluate the neuroprotective potential of HFP034. We showed that HFP034 inhibits 4-aminopyridine (4-AP)-induced glutamate release from synaptosomes, and this inhibition was absent in the absence of extracellular calcium. HFP034-mediated inhibition of glutamate release was associated with decreased 4-AP-evoked Ca2+ level elevation and had no effect on synaptosomal membrane potential. The inhibitory effect of HFP034 on evoked glutamate release was suppressed by blocking P/Q-type Ca2+ channels and protein kinase C (PKC). Furthermore, HFP034 inhibited the phosphorylation of PKC and its substrate, myristoylated alanine-rich C kinase substrate (MARCKS) in synaptosomes. We also observed that HFP034 pretreatment reduced neuronal death, glutamate concentration, glial activation, and the levels of endoplasmic reticulum stress-related proteins, calpains, glucose-regulated protein 78 (GRP 78), C/EBP homologous protein (CHOP), and caspase-12 in the hippocampus of KA-injected rats. We conclude that HFP034 is a neuroprotective agent that prevents glutamate excitotoxicity, and we suggest that this effect involves inhibition of presynaptic glutamate release through the suppression of P/Q-type Ca2+ channels and PKC/MARCKS pathways.


Assuntos
Ácido Glutâmico , Sinaptossomos , 4-Aminopiridina/farmacologia , Animais , Cálcio/metabolismo , Córtex Cerebral/metabolismo , Ácido Glutâmico/metabolismo , Ácido Caínico/farmacologia , Proteína Quinase C/metabolismo , Ratos , Ratos Sprague-Dawley , Sinaptossomos/metabolismo , ortoaminobenzoatos
15.
Int J Mol Sci ; 23(8)2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35456948

RESUMO

Current anti-seizure drugs fail to control approximately 30% of epilepsies. Therefore, there is a need to develop more effective anti-seizure drugs, and medicinal plants provide an attractive source for new compounds. This study aimed to evaluate the possible anti-seizure and neuroprotective effects of neferine, an alkaloid from the lotus seed embryos of Nelumbo nucifera, in a kainic acid (KA)-induced seizure rat model and its underlying mechanisms. Rats were intraperitoneally (i.p.) administrated neferine (10 and 50 mg/kg) 30 min before KA injection (15 mg/kg, i.p.). Neferine pretreatment increased seizure latency and reduced seizure scores, prevented glutamate elevation and neuronal loss, and increased presynaptic protein synaptophysin and postsynaptic density protein 95 expression in the hippocampi of rats with KA. Neferine pretreatment also decreased glial cell activation and proinflammatory cytokine (interleukin-1ß, interleukin-6, tumor necrosis factor-α) expression in the hippocampi of rats with KA. In addition, NOD-like receptor 3 (NLRP3) inflammasome, caspase-1, and interleukin-18 expression levels were decreased in the hippocampi of seizure rats pretreated with neferine. These results indicated that neferine reduced seizure severity, exerted neuroprotective effects, and ameliorated neuroinflammation in the hippocampi of KA-treated rats, possibly by inhibiting NLRP3 inflammasome activation and decreasing inflammatory cytokine secretion. Our findings highlight the potential of neferine as a therapeutic option in the treatment of epilepsy.


Assuntos
Alcaloides , Antineoplásicos , Benzilisoquinolinas , Fármacos Neuroprotetores , Alcaloides/farmacologia , Alcaloides/uso terapêutico , Animais , Benzilisoquinolinas/farmacologia , Benzilisoquinolinas/uso terapêutico , Citocinas/metabolismo , Inflamassomos/metabolismo , Ácido Caínico/efeitos adversos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Ratos , Sementes/metabolismo , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico
16.
Int J Mol Sci ; 23(21)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36362193

RESUMO

The inhibition of synaptic glutamate release to maintain glutamate homeostasis contributes to the alleviation of neuronal cell injury, and accumulating evidence suggests that natural products can repress glutamate levels and associated excitotoxicity. In this study, we investigated whether eupatilin, a constituent of Artemisia argyi, affected glutamate release in rat cortical nerve terminals (synaptosomes). Additionally, we evaluated the effect of eupatilin in an animal model of kainic acid (KA) excitotoxicity, particularly on the levels of glutamate and N-methyl-D-aspartate (NMDA) receptor subunits (GluN2A and GluN2B). We found that eupatilin decreased depolarization-evoked glutamate release from rat cortical synaptosomes and that this effect was accompanied by a reduction in cytosolic Ca2+ elevation, inhibition of P/Q-type Ca2+ channels, decreased synapsin I Ca2+-dependent phosphorylation and no detectable effect on the membrane potential. In a KA-induced glutamate excitotoxicity rat model, the administration of eupatilin before KA administration prevented neuronal cell degeneration, glutamate elevation, glutamate-generating enzyme glutaminase increase, excitatory amino acid transporter (EAAT) decrease, GluN2A protein decrease and GluN2B protein increase in the rat cortex. Taken together, the results suggest that eupatilin depresses glutamate exocytosis from cerebrocortical synaptosomes by decreasing P/Q-type Ca2+ channels and synapsin I phosphorylation and alleviates glutamate excitotoxicity caused by KA by preventing glutamatergic alterations in the rat cortex. Thus, this study suggests that eupatilin can be considered a potential therapeutic agent in the treatment of brain impairment associated with glutamate excitotoxicity.


Assuntos
Artemisia , Síndromes Neurotóxicas , Ratos , Animais , Ácido Glutâmico/metabolismo , Sinapsinas/metabolismo , Artemisia/metabolismo , 4-Aminopiridina/farmacologia , Ratos Sprague-Dawley , Córtex Cerebral/metabolismo , Cálcio/metabolismo , Sinaptossomos/metabolismo , Exocitose , Ácido Caínico/farmacologia , Síndromes Neurotóxicas/metabolismo
17.
Int J Mol Sci ; 23(15)2022 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-35955884

RESUMO

Excessive glutamate release is known to be involved in the pathogenesis of neurological diseases, and suppression of glutamate release from nerve terminals is considered to be a treatment strategy. In this study, we investigated whether isosaponarin, a flavone glycoside isolated from wasabi leaves, could affect glutamate release in rat cerebral cortex nerve terminals (synaptosomes). The release of glutamate was evoked by the K+ channel blocker 4-aminopyridine (4-AP) and measured by an online enzyme-coupled fluorimetric assay. Isosaponarin produced a concentration-dependent inhibition of 4-AP-evoked glutamate release with a half-maximum inhibition of release value of 22 µM. The inhibition caused by isosaponarin was prevented by eliminating extracellular Ca2+ or by using bafilomycin A1, an inhibitor of synaptic vesicle exocytosis. Isosaponarin decreased intrasynaptosomal rises in Ca2+ levels that were induced by 4-AP, without affecting the synaptosomal membrane potential. The isosaponarin-induced inhibition of glutamate release was significantly prevented in synaptosomes that were pretreated with a combination of the calcium channel blockers ω-conotoxin GVIA (N-type) and ω-agatoxin IVA (P/Q-types). The protein kinase C (PKC) pan-inhibitor GF109203X and the Ca2+-dependent PKC inhibitor Go6976 abolished the inhibition of glutamate release by isosaponarin, while the Ca2+-independent PKC inhibitor rottlerin did not show any effect. The results from immunoblotting assays also showed that isosaponarin lowered PKC, PKCα, synaptosomal-associated protein of 25 kDa (SNAP-25), and myristoylated alanine-rich C-kinase substrate (MARCKS) phosphorylation induced by 4-AP. In addition, FM1-43-labeled synaptic vesicles in synaptosomes showed that treatment with isosaponarin resulted in an attenuation of the 4-AP-induced decrease in fluorescence intensity that is consistent with glutamate release. Transmission electron microscopy of synaptosomes also provided evidence that isosaponarin altered the number of synaptic vesicles. These results indicate that isosaponarin suppresses the Ca2+-dependent PKC/SNAP-25 and MARCKS pathways in synaptosomes, causing a decrease in the number of available synaptic vesicles, which inhibits vesicular glutamate release from synaptosomes.


Assuntos
Ácido Glutâmico , Sinaptossomos , Animais , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Córtex Cerebral/metabolismo , Ácido Glutâmico/metabolismo , Potenciais da Membrana , Terminações Nervosas/metabolismo , Ratos , Ratos Sprague-Dawley , Sinaptossomos/metabolismo
18.
Molecules ; 27(3)2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35164225

RESUMO

Excessive release of glutamate induces excitotoxicity and causes neuronal damage in several neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for preventing and treating neurological disorders. Dehydrocorydaline (DHC), an active alkaloid compound isolated from Corydalis yanhusuo, possesses neuroprotective capacity. The present study investigated the effect of DHC on glutamate release using a rat brain cortical synaptosome model. Our results indicate that DHC inhibited 4-aminopyridine (4-AP)-evoked glutamate release and elevated intrasynaptosomal calcium levels. The inhibitory effect of DHC on 4-AP-evoked glutamate release was prevented in the presence of the vesicular transporter inhibitor bafilomycin A1 and the N- and P/Q-type Ca2+ channel blocker ω-conotoxin MVIIC but not the intracellular inhibitor of Ca2+ release dantrolene or the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157. Moreover, the inhibitory effect of DHC on evoked glutamate release was prevented by the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) inhibitor PD98059. Western blotting data in synaptosomes also showed that DHC significantly decreased the level of ERK1/2 phosphorylation and synaptic vesicle-associated protein synapsin I, the main presynaptic target of ERK. Together, these results suggest that DHC inhibits presynaptic glutamate release from cerebrocortical synaptosomes by suppressing presynaptic voltage-dependent Ca2+ entry and the MAPK/ERK/synapsin I signaling pathway.


Assuntos
Alcaloides/farmacologia , Cálcio/metabolismo , Córtex Cerebral/efeitos dos fármacos , Corydalis/química , Ácido Glutâmico/metabolismo , Tecido Nervoso/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio/química , Córtex Cerebral/metabolismo , Masculino , Tecido Nervoso/metabolismo , Ratos , Ratos Sprague-Dawley
19.
Medicina (Kaunas) ; 58(1)2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-35056379

RESUMO

Idiopathic multicentric Castleman disease (iMCD) is characterized by the benign proliferation of lymphoid cells in multiple regions. However, the co-occurrence of epithelial malignancy and idiopathic multicentric Castleman disease (iMCD) is rarely reported. Herein, we present a case of iMCD mimicking lymph nodal metastasis of Marjolin's ulcer in the lower extremity. A 53-year-old male presented with an unhealed chronic ulcer on the left lower leg and foot accompanied by an enlarged mass in the left inguinal region. Intralesional biopsy was performed, and pathological examination showed squamous cell carcinoma (SCC). Imaged studies revealed left calcaneus bone invasion, and lymph nodal metastasis was suspected by the cancer TNM staging of T4N2M0 pre-operatively. The patient received below-knee amputation and lymph node dissection; intraoperative histological examination showed no lymphatic nodal malignancy and diagnosed the patient as having iMCD with lymphadenopathy. The patient recovered uneventfully and was referred to a hematologist for further treatment.


Assuntos
Carcinoma de Células Escamosas , Hiperplasia do Linfonodo Gigante , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/cirurgia , Hiperplasia do Linfonodo Gigante/complicações , Hiperplasia do Linfonodo Gigante/cirurgia , Humanos , Extremidade Inferior/cirurgia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Úlcera
20.
Medicina (Kaunas) ; 58(3)2022 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-35334626

RESUMO

A thyroid storm is an extreme manifestation of thyrotoxicosis, and is life threatening without an early diagnosis. Pregnancy or childbirth may worsen maternal hyperthyroidism or induce the development of a thyroid storm. Gestational hypertension, a disorder defined as new-onset hypertension, develops after 20 weeks of gestation and shares symptoms with a thyroid storm. The diagnosis of a thyroid storm may be challenging in patients with gestational hypertension. To highlight the significance of early thyrotoxicosis-related gastrointestinal symptoms, we report a case of a 38-year-old woman with a twin pregnancy, who was diagnosed with gestational hypertension, and then developed a thyroid storm during the peripartum period. She complained of nausea and abdominal pain, followed by tachycardia, hypertension, and a disturbance of consciousness with desaturation. After emergency caesarean section, fever, diarrhea, and high-output heart failure, with pulmonary edema, were noted during the postoperative period in the intensive care unit. The diagnosis of a thyroid storm was confirmed using the Burch-Wartofsky point scale, which was 75 points. In this patient, the uncommon gastrointestinal symptoms, as initial manifestations of thyrotoxicosis, indicated the development of a thyroid storm. The distinguished presentation of thyrotoxicosis-induced cardiomyopathy and peripartum cardiomyopathy also helped in the differential diagnosis between a thyroid storm and gestational hypertension. Aggressive treatment for thyrotoxicosis should not be delayed because of a missed diagnosis.


Assuntos
Cardiomiopatias , Hipertensão Induzida pela Gravidez , Crise Tireóidea , Tireotoxicose , Adulto , Cardiomiopatias/complicações , Cesárea/efeitos adversos , Feminino , Humanos , Gravidez , Crise Tireóidea/complicações , Crise Tireóidea/diagnóstico , Tireotoxicose/complicações
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa