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1.
Environ Toxicol ; 39(5): 2927-2936, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38303669

RESUMO

Macrophages play an important role in defending the body against invading pathogens. In the face of pathogens, macrophages become activated and release toxic materials that disrupt the pathogens. Macrophage overactivation can lead to severe illness and inflammation. Wogonin has several therapeutic effects, including anti-inflammatory, anticancer, antioxidant, and neuroprotective effects. No studies have investigated the cytotoxic effects of wogonin at concentrations of more than 0.1 mM in RAW264.7 cells. In this study, RAW 264.7 cells were treated with wogonin, which, at concentrations of more than 0.1 mM, had cytotoxic and genotoxic effects in the RAW264.7 cells, leading to apoptosis and necrosis. Further, wogonin at concentrations of more than 0.1 mM induced caspase-3, caspase-8, and caspase-9 activation and mitochondrial dysfunction and death receptor expression. These results suggest that wogonin induces apoptosis through upstream intrinsic and extrinsic pathways by exhibiting cytotoxic and genotoxic effects.


Assuntos
Apoptose , Flavanonas , Flavanonas/farmacologia , Macrófagos , Dano ao DNA
2.
Environ Toxicol ; 39(5): 2970-2979, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38314619

RESUMO

Cyclizine, an over-the-counter and prescription antihistamine, finds widespread application in the prevention and treatment of motion sickness, encompassing symptoms such as nausea, vomiting, dizziness, along with its effectiveness in managing vertigo. However, the overuse or misuse of cyclizine may lead to hallucinations, confusion, tachycardia, and hypertension. The molecular mechanisms underlying cyclizine-induced cytotoxicity and apoptosis remain unclear. During the 24 h incubation duration, RAW264.7 macrophages were exposed to different concentrations of cyclizine. Cytotoxicity was assessed through the lactate dehydrogenase assay. Flow cytometry employing annexin V-fluorescein isothiocyanate and propidium iodide was utilized to evaluate apoptosis and necrosis. Caspase activity and mitochondrial dysfunction were evaluated through a fluorogenic substrate assay and JC-1 dye, respectively. Flow cytometry employing fluorogenic antibodies was utilized to evaluate the release of cytochrome c and expression of death receptor, including tumor necrosis factor-α receptor and Fas receptor. Western blotting was utilized to evaluate the expression of the Bcl2 and Bad apoptotic regulatory proteins. The findings unveiled from the present study demonstrated that cyclizine exerted a concentration-dependent effect on RAW264.7 macrophages, leading to the induction of cytotoxicity, apoptosis, and necrosis. This compound further activated the intrinsic apoptotic pathway by inducing mitochondrial dysfunction, Bcl2/Bad exchange expression, cytochrome c liberation, and activation of caspases contained caspase 3, 8, and 9. Moreover, the activation of the extrinsic apoptotic pathway was observed as cyclizine induced the upregulation of death receptors and increased caspase activities. Based on our investigations, it can be inferred that cyclizine prompts cytotoxicity and apoptosis in RAW264.7 macrophages in a concentration-dependent manner by triggering both the intrinsic and extrinsic apoptotic pathways.


Assuntos
Ciclizina , Doenças Mitocondriais , Humanos , Ciclizina/metabolismo , Ciclizina/farmacologia , Citocromos c/metabolismo , Mitocôndrias/metabolismo , Apoptose , Caspases/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Macrófagos , Necrose/metabolismo , Doenças Mitocondriais/metabolismo
3.
J Am Chem Soc ; 145(25): 13520-13525, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37310230

RESUMO

We report biosynthetic pathways that can synthesize and transform conjugated octaenes and nonaenes to complex natural products. The biosynthesis of (-)-PF1018 involves an enzyme PfB that can control the regio-, stereo-, and periselectivity of multiple reactions starting from a conjugated octaene. Using PfB as a lead, we discovered a homologous enzyme, BruB, that facilitates diene isomerization, tandem 8π-6π-electrocyclization, and a 1,2-divinylcyclobutane Cope rearrangement to generate a new-to-nature compound.


Assuntos
Produtos Biológicos , Produtos Biológicos/metabolismo , Isomerismo , Polienos , Ciclização
4.
Nat Prod Rep ; 40(1): 89-127, 2023 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-36125308

RESUMO

Covering: 2010 to 2022Heterologous expression of natural product biosynthetic gene clusters (BGCs) has become a widely used tool for genome mining of cryptic pathways, bottom-up investigation of biosynthetic enzymes, and engineered biosynthesis of new natural product variants. In the field of fungal natural products, heterologous expression of a complete pathway was first demonstrated in the biosynthesis of tenellin in Aspergillus oryzae in 2010. Since then, advances in genome sequencing, DNA synthesis, synthetic biology, etc. have led to mining, assignment, and characterization of many fungal BGCs using various heterologous hosts. In this review, we will highlight key examples in the last decade in integrating heterologous expression into genome mining and biosynthetic investigations. The review will cover the choice of heterologous hosts, prioritization of BGCs for structural novelty, and how shunt products from heterologous expression can reveal important insights into the chemical logic of biosynthesis. The review is not meant to be exhaustive but is rather a collection of examples from researchers in the field, including ours, that demonstrates the usefulness and pitfalls of heterologous biosynthesis in fungal natural product discovery.


Assuntos
Produtos Biológicos , Produtos Biológicos/metabolismo , Família Multigênica , Vias Biossintéticas/genética
5.
J Acoust Soc Am ; 153(4): 2406, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37092944

RESUMO

A data-driven approach to constructing a prosodic grammar of Mandarin read speech is proposed. Prosodic labeling is performed, first, on a large speech corpus with syntactic-tree parsing to add four-level break indices. Two types of prosodic grammatical rules are explored. One type is composed of simplified rules to compute break-type distributions at critical junctures for 5 phrase-level and 11 basic syntactic patterns. The other type entails detailed rules to compute break-type distributions conditioned on syntactic function for four determinative-measure (DM)-related syntactic patterns. Effectiveness of the approach was confirmed by meaningful interpretations of the resulting main prosodic patterns and outliers of targeted syntactic patterns by inferred rules. The main findings are given below. Strong paused breaks are found at VE-clause object (VE, active verb with a sentential object) junctures and junctures after idioms. For DM-related patterns, the entropies of break-type distributions decrease significantly as syntactic functions are involved; break-type distributions on both edges are seriously affected by their syntactic functions; when acting as subject (S) and object (O), their prosodic phenomena support the tendency of Mandarin to be S(VO) (V, verb); strong paused breaks at postboundaries of DM-2-DM-4 are caused by their more complex syntactic structures and greater lengths; and the insertions of modifier + DE (special tag for the word DE) into DM-N (N, noun) junctures cause more paused-break insertions at junctures after DMs.


Assuntos
Percepção da Fala , Fala , Linguística , Idioma , Estimulação Acústica
6.
Environ Toxicol ; 38(12): 2819-2825, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37551787

RESUMO

Cyclizine exhibits sedation and treatment of nausea, vomiting, and motion sickness due to antihistaminic and antimuscarinic effects. Cyclizine has the potential for abuse due to the hallucinogenic and euphoric effect. The response of overdose and illegal abuse of cyclizine includes confusion, tremors, chest pain, ataxia, seizures, and lead to suicide. Macrophage plays the important role in the innate immunity. However, over activation of macrophages results in pro-inflammatory responses in peripheral tissues. In the present study, cyclizine was found to enhanced the generation of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. We further found that secretion of nitrogen oxide (NO) induced by cyclizine via expression of inducible nitric oxide synthases (iNOS). Cyclizine exhibited parallel stimulation of phosphorylation of nuclear factor-κB (NFκB) p65, and its up-stream factor Akt. These results indicated that the expression of pro-inflammatory cytokines, pro-inflammatory mediators, and adhesion molecules would be induced by cyclizine via activation of Akt-NFκB pathway in macrophages.


Assuntos
NF-kappa B , Proteínas Proto-Oncogênicas c-akt , Humanos , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ciclizina/metabolismo , Ciclizina/farmacologia , Anti-Inflamatórios/farmacologia , Macrófagos , Citocinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Lipopolissacarídeos/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo
7.
Environ Toxicol ; 37(12): 3007-3012, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36178853

RESUMO

Composites, resins, and sealants that are commonly used in orthopedics and dentistry are based on 2,2-bis[p-(2'-hydroxy-3'-methacryloxypropoxy)phenylene]propane (BisGMA), which induces proinflammatory responses in macrophages. The present study aimed to explore the anti-inflammatory responses of wogonin, which is a natural dihydroxyl flavonoid compound, in BisGMA-treated macrophages. According to the findings, wogonin exhibits anti-inflammatory, antiallergic, anticancer, and antioxidative properties. The generation of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) were noted to be inhibited by wogonin in BisGMA-treated macrophages. Furthermore, the production of proinflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 was reduced. In addition, BisGMA-induced nuclear factor (NF)-κB p65 phosphorylation and inhibitor of κB (IκB) degradation were inhibited. Finally, the BisGMA-induced phosphorylation of mitogen-activated protein kinases (MAPKs), including p38 MAPK, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) was inhibited. All these effects were induced by wogonin in the macrophages in a concentration-dependent manner. Similar inhibitory effects of wogonin were observed on the production of NO and proinflammatory cytokines, expression of iNOS, phosphorylation of NF-κB p65 and MAPK, and degradation of IκB. These results indicated that rutin is a potential anti-inflammatory agent for BisGMA-treated macrophages that undergo NFκB p65 phosphorylation and IκB degradation through upstream MAPK phosphorylation. Therefore, wogonin inhibits BisGMA-induced proinflammatory responses in macrophages through the regulation of the NFκB pathway and its upstream factor, MAPK.


Assuntos
Lipopolissacarídeos , NF-kappa B , NF-kappa B/metabolismo , Lipopolissacarídeos/farmacologia , Óxido Nítrico Sintase Tipo II/metabolismo , Macrófagos , Anti-Inflamatórios/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Óxido Nítrico/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fosforilação , Citocinas/metabolismo , Ciclo-Oxigenase 2/metabolismo
8.
Environ Toxicol ; 36(1): 45-54, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32830914

RESUMO

Bisphenol-A-glycidyldimethacrylate (BisGMA) is a resin monomer frequently used in dentin restorative treatments. The leakage of BisGMA monomer from BisGMA-based polymeric resins can lead to cytotoxicity in macrophages. Rutin has various beneficial bioeffects, including antioxidation and antiinflammation. In this study, we found that pretreatment of RAW264.7 macrophages with rutin-inhibited cytotoxicity induced by BisGMA in a concentration-dependent manner. BisGMA-induced apoptosis, which was detected by levels of phosphatidylserine from the internal to the external membrane and formation of sub-G1, and genotoxicity, which was detected by cytokinesis-blocked micronucleus and single-cell gel electrophoresis assays, were inhibited by rutin in a concentration-dependent manner. Rutin suppressed the BisGMA-induced activation of caspase-3 and -9 rather than caspase-8. Rutin inhibited the activation of the mitochondrial apoptotic pathway, including cytochrome C release and mitochondria disruption, after macrophages were treated with BisGMA. Finally, BisGMA-induced reactive oxygen species (ROS) generation and antioxidant enzyme (AOE) deactivation could be reversed by rutin. Parallel trends were observed in the elevation of AOE activation and inhibition of ROS generation, caspase-3 activity, mitochondrial apoptotic pathway activation, and genotoxicity. These results suggested that rutin suppressed BisGMA-induced cytotoxicity through genotoxicity, the mitochondrial apoptotic pathway, and relatively upstream factors, including reduction of ROS generation and induction of AOE.

9.
Ecotoxicol Environ Saf ; 193: 110348, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32114240

RESUMO

Due to rapid advances in the era of electronic technologies, indium has played the important material for the production of liquid crystal display screens in the semiconductor and optoelectronic industries. The present study focuses on evaluating the toxic effects and related mechanisms of indium chloride (InCl3) on RAW264.7 macrophages. Cytotoxicity was induced by InCl3 in a concentration- and time-dependent manner. InCl3 had the ability to induce macrophage death through apoptosis rather than through necrosis. According to the cytokinesis-block micronucleus assay and alkaline single-cell gel electrophoresis assay, InCl3 induced DNA damage, also called genotoxicity, in a concentration-dependent manner. Cysteine-dependent aspartate-directed protease (caspase)-3, -8, and -9 were activated by InCl3 in a concentration-dependent manner. Mitochondria dysfunction and cytochrome c release from the mitochondria were induced by InCl3 in a concentration-dependent manner. Downregulation of BCL2 and upregulation of BAD were induced by InCl3 in a concentration-dependent manner. More, we proposed that InCl3 treatment generated reactive oxygen species (ROS) in a concentration-dependent manner. In conclusion, the current study revealed that InCl3 induced macrophage cytotoxicity, apoptosis, and genotoxicity via a mitochondria-dependent apoptotic pathway and ROS generation.


Assuntos
Dano ao DNA , Índio/toxicidade , Macrófagos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Citotoxinas/toxicidade , Macrófagos/metabolismo , Camundongos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Proteína de Morte Celular Associada a bcl/metabolismo
10.
Appl Microbiol Biotechnol ; 103(8): 3277-3287, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30859257

RESUMO

Secondary metabolites (SM) produced by fungi and bacteria have long been of exceptional interest owing to their unique biomedical ramifications. The traditional discovery of new natural products that was mainly driven by bioactivity screening has now experienced a fresh new approach in the form of genome mining. Several bioinformatics tools have been continuously developed to detect potential biosynthetic gene clusters (BGCs) that are responsible for the production of SM. Although the principles underlying the computation of these tools have been discussed, the biological background is left underrated and ambiguous. In this review, we emphasize the biological hypotheses in BGC formation driven from the observations across genomes in bacteria and fungi, and provide a comprehensive list of updated algorithms/tools exclusively for BGC detection. Our review points to a direction that the biological hypotheses should be systematically incorporated into the BGC prediction and assist the prioritization of candidate BGC.


Assuntos
Bactérias/genética , Biologia Computacional , Fungos/genética , Família Multigênica/genética , Metabolismo Secundário/genética , Bactérias/química , Bactérias/metabolismo , Produtos Biológicos/metabolismo , Resistência Microbiana a Medicamentos/genética , Fungos/química , Fungos/metabolismo , Duplicação Gênica , Transferência Genética Horizontal , Genoma Microbiano/genética
11.
J Acoust Soc Am ; 145(4): 2576, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31046330

RESUMO

In this paper, a hierarchical prosody model (HPM)-based method for Mandarin spontaneous speech is proposed. First, an HPM is designed for describing relations among acoustic features of utterances, linguistic features of texts, and prosodic tags representing the underlying hierarchical prosodic structures of utterances. Subsequently, a sequential optimization algorithm is employed to train the HPM based on a large conversational speech corpus, the Mandarin Conversational Dialogue Corpus (MCDC), which features orthographic transcriptions and prosodic event annotations. In this unsupervised training method, all utterances of the MCDC are labeled with two types of prosodic tags, namely, break and prosodic states, automatically and simultaneously. After training, the HPM parameters are examined to identify critical prosodic properties of Mandarin spontaneous speech, which are then compared with their counterparts in the read-speech HPM. The prosodic tags on the studied utterances enable mapping of various prosodic events onto the hierarchical prosodic structures of the utterances. Prosodic analyses of some disfluent events are conducted using the prosodic tags affixed to the MCDC. Finally, an application of the HPM to assist in Mandarin spontaneous-speech recognition is discussed. Significant relative error rate reductions of 9.0%, 9.2%, 15.6%, and 7.3% are obtained for base-syllable, character, tone, and word recognition, respectively.

12.
Angew Chem Int Ed Engl ; 58(51): 18414-18418, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31618514

RESUMO

Aculenes are a unique class of norsequiterpenes (C14 ) that are produced by Aspergillus aculeatus. The nordaucane skeleton in aculenes A-D may be derived from an ent-daucane precursor through demethylation, however, the enzymes involved remain unexplored. We identified the biosynthetic gene cluster and characterized the biosynthetic pathway based on gene inactivation, feeding experiments, and heterologous reconstitution in Saccharomyces cerevisiae and Aspergillus oryzae. We discovered that three cytochrome P450 monoxygenases are required to catalyze the stepwise demethylation process. AneF converts the 12-methyl group into a carboxylic acid and AneD installs the 10-hydroxy group for later tautomerization and stabilization. Finally, AneG installs an electron-withdrawing carbonyl group at the C-2 position, which triggers C-12 decarboxylation to yield the nordaucane skeleton. Additionally, a terpene cyclase (AneC) was found that forms a new product (dauca-4,7-diene).


Assuntos
Vias Biossintéticas/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Terpenos/metabolismo , Catálise , Desmetilação , Humanos
13.
Environ Toxicol Pharmacol ; 108: 104468, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38759849

RESUMO

Chlorpyrifos, widely used for pest control, is known to have various harmful effects, although its toxic effects in macrophages and the mechanisms underlying its toxicity remain unclear. The present study investigated the toxic effects of chlorypyrifos in a macrophage cell line. Here, we found that chlorpyrifos induced cytotoxicity and genotoxicity in RAW264.7 macrophages. Moreover, chlorpyrifos induced intracellular ROS production, subsequently leading to lipid peroxidation. Chlorpyrifos reduced the activation of antioxidative enzymes including superoxide dismutase, catalase, and glutathione peroxidase. Chlorpyrifos upregulated HO-1 expression and activated the Keap1-Nrf2 pathway, as indicated by enhanced Nrf2 phosphorylation and Keap1 degradation. Chlorpyrifos exerted effects on the following in a dose-dependent manner: cytotoxicity, genotoxicity, lipid peroxidation, intracellular ROS production, antioxidative enzyme activity reduction, HO-1 expression, Nrf2 phosphorylation, and Keap1 degradation. Notably, N-acetyl-L-cysteine successfully inhibited chlorpyrifos-induced intracellular ROS generation, cytotoxicity, and genotoxicity. Thus, chlorpyrifos may induce cytotoxicity and genotoxicity by promoting intracellular ROS production and suppressing the antioxidative defense system activation in macrophages.


Assuntos
Clorpirifos , Inseticidas , Proteína 1 Associada a ECH Semelhante a Kelch , Macrófagos , Fator 2 Relacionado a NF-E2 , Espécies Reativas de Oxigênio , Clorpirifos/toxicidade , Animais , Camundongos , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Inseticidas/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Antioxidantes/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Heme Oxigenase-1/genética , Superóxido Dismutase/metabolismo , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Proteínas de Membrana
14.
Artigo em Inglês | MEDLINE | ID: mdl-35682430

RESUMO

Depression is a common mental disorder that affects more than 264 million people worldwide. Anxiety, diabetes, Alzheimer's disease, myocardial infarction, and cancer, among other disorders, are known to increase the risk of depression. Exposure to ultraviolet B (UVB) can cause human serotonin levels to increase. The vitamin D pathway is one mechanism through which ultraviolet light absorbed through the skin can affect mood; however, UVB exposure is known to increase the risk of cancer. In this study, we explored the effects of prolonged exposure to UVB on depression. Data were retrieved from the Taiwan National Health Insurance Research Database for 2008 to 2013. Each patient with depression was matched 1:4 with a comparison patient by sex and age (±5 years); thus, the study included 23,579 patients with depression and 94,316 healthy controls for comparison. The patients had been exposed to UVB for at least 1 year to observe the cumulative effect of UVB exposure. Based on the World Health Organization UV index, we divided the observation period data into five UV levels: low, moderate, high, very high, and extreme. A multivariate Poisson regression model was used to assess the risk of depression according to UVB exposure level, adjusting for sex, age, income, urbanization level, month, and comorbidities. The results revealed that the incidence rate ratio (IRR) for patients with depression was 0.889 for moderate levels (95% CI 0.835-0.947), 1.134 for high levels (95% CI: 1.022-1.260), 1.711 for very high levels (95% CI: 1.505-1.945), and 2.785 for extreme levels (95% CI: 2.439-3.180) when compared to low levels. Moderate levels of UVB lowered the risk of depression, while high levels of UVB gradually increased the risk. We propose that UVB at normal concentrations can effectively improve depression. However, exposure to high concentrations of UVB damage DNA results in physical diseases such as skin cancer, which increase the risk of depression.


Assuntos
Psoríase , Neoplasias Cutâneas , Adulto , Estudos de Casos e Controles , Depressão/epidemiologia , Humanos , Neoplasias Cutâneas/etiologia , Raios Ultravioleta/efeitos adversos
15.
J Phys Condens Matter ; 23(3): 035301, 2011 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-21406862

RESUMO

In this paper we study the characteristics of subwavelength imaging of a photonic crystal (PhC) superlens under the influence of source displacement. For square and triangular lattice photonic crystal lenses, we investigate the influence of changing the lateral position of a single point source on imaging uniformity and stability. We also study the effect of changing the geometrical center of a pair of sources on the resolution of the double image. Both properties are found to be sensitive to the displacement, which implies that a PhC slab cannot be treated seriously as a flat lens. We also show that by introducing material absorption into the dielectric cylinders of the PhC slab and widening the lateral width of the slab, the imaging uniformity and stability can be substantially improved. This study helps us to clarify the underlying mechanisms of some recently found phenomena concerning imaging instability.

16.
Brain Res ; 1767: 147539, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34052258

RESUMO

The rostral ventromedial medulla (RVM) plays a key role in the endogenous modulation of nociceptive transmission in the central nervous system (CNS). The primary aim of this study was to examine whether the activities of RVM neurons were related to craniofacial nociceptive behaviour (jaw-motor response, JMR) as well as the tail-flick response (TF). The activities of RVM neurons and TF and JMR evoked by noxious heating of the tail or perioral skin were recorded simultaneously in lightly anaesthetized rats. Tail or perioral heating evoked the TF and JMR, and the latency of the JMR was significantly shorter (P < 0.001) than that of the TF. Of 89 neurons recorded in RVM, 40 were classified as ON-cells, 27 as OFF-cells, and 22 as NEUTRAL-cells based on their responsiveness to heating of the tail. Heating at either site caused an increase in ON-cell and decrease in OFF-cell activity before the occurrence of the TF and JMR, but did not alter the activity of NEUTRAL cells. Likewise, noxious stimulation of the temporomandibular joint had similar effects on RVM neurons. These findings reveal that the JMR is a measure of the excitability of trigeminal and spinal nociceptive circuits in the CNS, and that the JMR as well as TF can be used for studying processes related to descending modulation of pain. The findings also support the view that RVM ON- and OFF-cells play an important role in the elaboration of diverse nociceptive behaviours evoked by noxious stimulation of widely separated regions of the body.


Assuntos
Neurônios/fisiologia , Dor/fisiopatologia , Vias Aferentes/fisiologia , Animais , Mapeamento Encefálico , Face , Masculino , Bulbo/fisiologia , Vias Neurais/fisiologia , Nociceptividade/fisiologia , Nociceptores/fisiologia , Estimulação Física , Ratos , Ratos Sprague-Dawley , Reflexo/fisiologia , Crânio , Cauda
17.
J Neurosci ; 29(36): 11161-71, 2009 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-19741123

RESUMO

The aim of this study was to investigate whether astroglia in the medullary dorsal horn (trigeminal spinal subnucleus caudalis; Vc) may be involved in orofacial neuropathic pain following trigeminal nerve injury. The effects of intrathecal administration of the astroglial aconitase inhibitor sodium fluoroacetate (FA) were tested on Vc astroglial hyperactivity [as revealed by glial fibrillary acid protein (GFAP) labeling], nocifensive behavior, Vc extracellular signal-regulated kinase phosphorylation (pERK), and Vc neuronal activity in inferior alveolar nerve-transected (IANX) rats. Compared with sham-control rats, a significant increase occurred in GFAP-positive cells in ipsilateral Vc at postoperative day 7 in IANX rats, which was prevented following FA administration. FA significantly increased the reduced head withdrawal latency to high-intensity heat stimulation of the maxillary whisker pad skin in IANX rats, although it did not significantly affect the reduced escape threshold to low-intensity mechanical stimulation of the whisker skin in IANX rats. FA also significantly reduced the increased number of pERK-like immunoreactive cells in Vc and the enhanced Vc nociceptive neuronal responses following high-intensity skin stimulation that were documented in IANX rats, and glutamine administration restored the enhanced responses. These various findings provide the first documentation that astroglia is involved in the enhanced nociceptive responses of functionally identified Vc nociceptive neurons and in the associated orofacial hyperalgesia following trigeminal nerve injury.


Assuntos
Astrócitos/fisiologia , Dor/fisiopatologia , Células do Corno Posterior/fisiologia , Núcleo Inferior Caudal do Nervo Trigêmeo/fisiologia , Doenças do Nervo Trigêmeo/fisiopatologia , Animais , Astrócitos/química , Masculino , Bulbo/química , Bulbo/fisiologia , Dor/diagnóstico , Medição da Dor/métodos , Estimulação Física/métodos , Células do Corno Posterior/química , Ratos , Ratos Sprague-Dawley , Núcleo Inferior Caudal do Nervo Trigêmeo/química , Doenças do Nervo Trigêmeo/diagnóstico
18.
Tzu Chi Med J ; 32(4): 344-350, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33163379

RESUMO

OBJECTIVE: Safrole, also called shikimol and Sassafras, is the carcinogenic and phenylpropanoid compound extracted from Sassafras tree and anise, betel, and camphor. Moreover, a high concentration of safrole can be occur in the saliva because of betel nut or areca quid chewing which a common habit observed in Southern and Southeastern Asia. Notably, macrophages are crucial phagocytic cells of the immune system. Nonetheless, to date, no evidence has been reported regarding safrole-induced proinflammatory response and the corresponding mechanism in macrophages. MATERIALS AND METHODS: In the present study, the cytokines expression, NO generation, protein phosphorylation, and expression were assessed by enzyme-linked immunosorbent assay, Griess reagent, and Western blot assay, respectively. RESULTS: In this study, we determined that safrole induces the generation of nitric oxide and proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1ß, and IL-6 in RAW264.7 macrophages in a concentration-dependent manner. Furthermore, inhibitor of κB (IκB) degradation was caused by safrole in a concentration-dependent manner. In addition, the phosphorylation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) family, including p38 MAPK, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase, was induced by safrole began to increase at 10 µM and attained a plateau at 100 µM. CONCLUSION: These results indicated that safrole induces the expression of proinflammatory responses in macrophages through the NF-κB/IκB pathway and its upstream factor, MAPK family phosphorylation.

19.
Polymers (Basel) ; 12(6)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580382

RESUMO

Urethane dimethacrylate (UDMA) is a dimethacrylate-based resin monomer that can react with other related monomers and inorganic particles, causing hydrophobic polymerization through cross-linking upon light activation. UDMA polymers are commonly used for the reconstruction and reinforcement of teeth and bones. UDMA can become unbound and be released from light-cured polymer resins. Thus far, no evidence exists on the toxic effects of UDMA and its related working mechanisms for macrophages. Therefore, in the present study, we investigated the cytotoxicity, mode of cell death, DNA damage, caspase activities, mitochondrial dysfunction, and reactive oxygen species (ROS) generation in RAW264.7 macrophages treated with UDMA using the lactate dehydrogenase (LDH) assay kit, Annexin V-FITC and PI assays, micronucleus formation and comet assay, caspase fluorometric assay, JC-1 assay, and 2',7'-dichlorofluorescin diacetate (DCFH-DA) assay, respectively. Our results show that UDMA induced cytotoxicity; apoptosis and necrosis; genotoxicity, which is also called DNA damage; increased caspase-3, -8, and -9 activities; mitochondrial dysfunction; and intracellular ROS generation in a concentration-dependent manner in RAW264.7 macrophages. Thus, based on the observed inhibited concentration parallel trends, we concluded that UDMA induces toxic effects in macrophages. Furthermore, UDMA-induced intracellular ROS generation, cytotoxicity, and DNA damage were reduced by N-acetyl-L-cysteine.

20.
J Acoust Soc Am ; 125(2): 1164-83, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19206890

RESUMO

An unsupervised joint prosody labeling and modeling method for Mandarin speech is proposed, a new scheme intended to construct statistical prosodic models and to label prosodic tags consistently for Mandarin speech. Two types of prosodic tags are determined by four prosodic models designed to illustrate the hierarchy of Mandarin prosody: the break of a syllable juncture to demarcate prosodic constituents and the prosodic state to represent any prosodic domain's pitch-level variation resulting from its upper-layered prosodic constituents' influences. The performance of the proposed method was evaluated using an unlabeled read-speech corpus articulated by an experienced female announcer. Experimental results showed that the estimated parameters of the four prosodic models were able to explore and describe the structures and patterns of Mandarin prosody. Besides, certain corresponding relationships between the break indices labeled and the associated words were found, and manifested the connections between prosodic and linguistic parameters, a finding further verifying the capability of the method presented. Finally, a quantitative comparison in labeling results between the proposed method and human labelers indicated that the former was more consistent and discriminative than the latter in prosodic feature distributions, a merit of the method developed here on the applications of prosody modeling.


Assuntos
Sinais (Psicologia) , Idioma , Modelos Estatísticos , Acústica da Fala , Percepção da Fala , Algoritmos , Feminino , Humanos , Reconhecimento Fisiológico de Modelo , Percepção da Altura Sonora
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