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1.
Nano Lett ; 24(15): 4393-4399, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38569084

RESUMO

Highly tunable properties make Mn(Bi,Sb)2Te4 a rich playground for exploring the interplay between band topology and magnetism: On one end, MnBi2Te4 is an antiferromagnetic topological insulator, while the magnetic structure of MnSb2Te4 (MST) can be tuned between antiferromagnetic and ferrimagnetic. Motivated to control electronic properties through real-space magnetic textures, we use magnetic force microscopy (MFM) to image the domains of ferrimagnetic MST. We find that magnetic field tunes between stripe and bubble domain morphologies, raising the possibility of topological spin textures. Moreover, we combine in situ transport with domain manipulation and imaging to both write MST device properties and directly measure the scaling of the Hall response with the domain area. This work demonstrates measurement of the local anomalous Hall response using MFM and opens the door to reconfigurable domain-based devices in the M(B,S)T family.

2.
Int J Pharm ; 655: 124002, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38492898

RESUMO

Pterostilbene, a stilbene compound, demonstrates neuroprotective effects through its antioxidant and anti-inflammatory properties. However, pterostilbene exhibits low bioavailability. We developed a pterostilbene nanoemulsion with better release stability and particle size. Behavioral tests, including the Y maze, new object recognition, and water maze, revealed that the pterostilbene nanoemulsion demonstrated a more significant effect on improving learning and memory function than pterostilbene. Immunofluorescence analysis revealed that pterostilbene nanoemulsion was more potent in safeguarding hippocampal neurons and inhibiting apoptosis and oxidative stress than pterostilbene. Further results from the Western blot and quantitative reverse transcription polymerase chain reaction indicated that the enhanced efficacy of pterostilbene nanoemulsion may be attributed to its stronger promotion of the nuclear factor erythroid 2-related factor 2 signaling pathway. Hence, enhanced drug delivery efficiency decreased dosage requirements and increased the bioavailability of pterostilbene, thereby potentially providing a safe, effective, and convenient treatment option for patients with Alzheimer's disease.


Assuntos
Doença de Alzheimer , Estilbenos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Transdução de Sinais , Estilbenos/farmacologia , Estilbenos/uso terapêutico , Animais , Camundongos
3.
J Agric Food Chem ; 71(36): 13270-13283, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37624928

RESUMO

Ischemic stroke is a major risk factor in human health, yet there are no drugs to cure cerebral ischemia/reperfusion injury (CIRI). Inflammation plays a fundamental role in the consequences of CIRI. Isorhapontigenin (ISOR) exhibits great anti-inflammatory activity; however, it is unclear whether ISOR can treat ischemic stroke through an anti-inflammation effect. Here, middle cerebral artery occlusion/reperfusion (MCAO/R) was used to investigate the effects of ISOR on CIRI. The in vitro activity was measured in BV-2 cells exposed to oxygen-glucose deprivation/reperfusion. As measured by neurological scores, brain water content, and infarction, neurological dysfunction was improved in the ISOR group. The neuronal death and microglial activation in the ipsilateral cortex were reduced by ISOR. TLR4 signaling was significantly inhibited by ISOR in vivo and in vitro. By reverse molecular docking, cellular thermal shift, and drug affinity-responsive target stability assays, an aryl hydrocarbon receptor (AHR) was found to be a target of ISOR. Furthermore, AHR knockdown blocked the effect of ISOR on TLR4 signaling, suggesting that ISOR may regulate TLR4-mediated inflammation through AHR, thereby protecting neurons from CIRI. This study demonstrated that ISOR is a promising drug candidate for the treatment of ischemic stroke and provided a theoretical basis for the development of the medicinal value of ISOR-derived foods, such as grapes.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Traumatismo por Reperfusão , Humanos , Receptores de Hidrocarboneto Arílico/genética , Receptor 4 Toll-Like/genética , Simulação de Acoplamento Molecular , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/genética , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/genética
4.
Phytomedicine ; 119: 155011, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37562093

RESUMO

BACKGROUND: Alzheimer's disease (AD), the most prevalent form of dementia, remains untreatable. One of the factors that contributes to its progression is microglia-mediated inflammation. Pterostilbene, a compound isolated from Chinese dragon's blood, can reduce inflammation caused by overactive microglia. However, its effects on AD transgenic animals and the possible underlying mechanism remain unknown. METHODS: We evaluated the effect of pterostilbene on learning and memory difficulties in transgenic APP/PS1 mice. We used immunofluorescence to detect microglial activation and Aß aggregation. We explored the cellular mechanism of pterostilbene by establishing LPS- stimulated BV2 cells and oAß1-42- exposed HEK 293T cells that overexpress TLR4 and/or MD2 via lentivirus. We applied flow cytometry and immunoprecipitation to examine how pterostilbene regulates TLR4 signaling. RESULTS: Pterostilbene enhanced the learning and memory abilities of APP/PS1 mice and reduced microglial activation and Aß aggregation in their hippocampus. Pterostilbene alleviated oAß1-42-induced inflammation, which required the involvement of MD2. Pterostilbene disrupted the binding between TLR4 and MD2, which may further prevent TLR4 dimerization and subsequent inflammatory response. Moreover, pterostilbene restored the impaired endocytosis of oAß1-42 through an autophagy-dependent mechanism. CONCLUSION: This is the first demonstration that pterostilbene can potentially treat AD by blocking the interaction of TLR4 and MD2, thereby suppressing TLR4-mediated inflammation.


Assuntos
Doença de Alzheimer , Camundongos , Animais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Receptor 4 Toll-Like/metabolismo , Peptídeos beta-Amiloides/metabolismo , Camundongos Transgênicos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Microglia , Autofagia , Endocitose , Modelos Animais de Doenças
5.
Food Funct ; 14(1): 369-387, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36511396

RESUMO

Cognitive impairment is the main clinical feature following stroke, and microglia-mediated inflammatory response is a major contributor to it. Coreopsis tinctoria Nutt., an edible chrysanthemum, is commonly used as a functional ingredient in healthcare beverages and food. Okanin, the main active ingredient of Coreopsis tinctoria Nutt. flower, inhibits microglial activation. However, the role of okanin in cognitive impairment following ischemic stroke is still unknown. In this study, we investigated the effect of okanin on ischemic stroke and its underlying mechanism both in vivo and in vitro. Okanin was found to attenuate cognitive impairment in bilateral common carotid artery occlusion (BCCAO) mice, inhibit neuronal loss and microglial activation, decrease NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation, and increase miR-7 expression. Okanin suppressed NLRP3 inflammasome activation in oxygen-glucose deprivation (OGD) and lipopolysaccharide (LPS)-stimulated microglia by increasing miR-7 expression and inhibited microglia-induced neuronal injury. This study provides new insights into the role of okanin in ischemic stroke and shows that the miR-7/NLRP3 axis plays an important role in mediating the beneficial effects of okanin on cerebral ischemia. These findings suggest that okanin has great potential as a functional food for stroke recovery.


Assuntos
Disfunção Cognitiva , Coreopsis , AVC Isquêmico , MicroRNAs , Acidente Vascular Cerebral , Camundongos , Animais , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Microglia , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Artéria Carótida Primitiva/metabolismo
6.
Phytother Res ; 36(12): 4527-4541, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36146897

RESUMO

Ischemic stroke is a leading cause of death and disability worldwide. Post-ischemia, microglia respond immediately to the alternations in neuronal activity and mediate inflammation. Toll-like receptor 4 (TLR4) plays a key role in this phenomenon. To explore the effect of loureirin C, an effective compound from Chinese Dragon's blood, on ischemic stroke, Sprague-Dawley rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) with/without intragastric administration of loureirin C (7, 14, and 28 mg/kg). Loureirin C alleviated MCAO/R-induced brain impairment evaluated by neurological scores (p < 0.001), brain water content (p < 0.001), and cerebral infarct volume (p = 0.001). The neuroprotective (p < 0.001) and inhibitory effects on microglial activation (p < 0.001) of loureirin C were revealed by immunofluorescence. Rescue studies with TLR4 overexpression in BV-2 microglia showed that the antiinflammatory effect of loureirin C was attributable to the inhibition of TLR4 protein expression. Moreover, co-immunoprecipitation assays showed that the binding of Triad3A, an E3 ubiquitin ligase of TLR4, was increased by loureirin C (p = 0.003). Our study demonstrates that loureirin C could be a promising therapeutic agent for the management of ischemic stroke by inhibiting microglial activation, potentially by Triad3A-mediated promotion of TLR4 ubiquitination and degradation.


Assuntos
AVC Isquêmico , Traumatismo por Reperfusão , Animais , Ratos , Isquemia , NF-kappa B , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológico , Receptor 4 Toll-Like
7.
J Agric Food Chem ; 70(19): 5896-5910, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35532888

RESUMO

Pterostilbene, a methylated stilbene derived from many plant foods, has significant anti-inflammatory activity. Meanwhile, vascular dementia (VaD) is the second most common subtype of dementia, in which inflammation is one of the major pathogenic contributors. However, the protective effect of pterostilbene on VaD is not well understood. In this work, we investigated the effect of pterostilbene on VaD and explored its underlying mechanisms using in vivo and in vitro models. Y-maze and Morris water maze tests showed pterostilbene-attenuated cognitive impairment in mice with bilateral common carotid artery occlusion (BCCAO). The hippocampal neuronal death and microglial activation in BCCAO mice were also reduced by pterostilbene treatment. Further, pterostilbene inhibited the expression of TLR4 and downstream inflammatory cytokines in these mice, with similar results observed in an oxygen-glucose deprivation and reperfusion (OGD/R) BV-2 cell model. In addition, its anti-inflammatory effect on OGD/R BV-2 cells was partially blocked by TLR4 overexpression. Moreover, Triad3A-TLR4 interactions were increased by pterostilbene following enhanced ubiquitination and degradation of TLR4, and the inhibitory effect of pterostilbene on inflammation was blocked by Triad3A knockdown in OGD/R-stimulated BV-2 cells. Together, these results reveal that pterostilbene could reduce vascular cognitive impairment and that Triad3A-mediated TLR4 degradation might be the key target.


Assuntos
Demência Vascular , Estilbenos , Receptor 4 Toll-Like , Animais , Anti-Inflamatórios/farmacologia , Glucose/metabolismo , Camundongos , Microglia/efeitos dos fármacos , Microglia/patologia , Estilbenos/farmacologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Ubiquitinação/efeitos dos fármacos
8.
Micromachines (Basel) ; 12(8)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34442568

RESUMO

Wafer bonding technology is one of the most effective methods for high-quality thin-film transfer onto different substrates combined with ion implantation processes, laser irradiation, and the removal of the sacrificial layers. In this review, we systematically summarize and introduce applications of the thin films obtained by wafer bonding technology in the fields of electronics, optical devices, on-chip integrated mid-infrared sensors, and wearable sensors. The fabrication of silicon-on-insulator (SOI) wafers based on the Smart CutTM process, heterogeneous integrations of wide-bandgap semiconductors, infrared materials, and electro-optical crystals via wafer bonding technology for thin-film transfer are orderly presented. Furthermore, device design and fabrication progress based on the platforms mentioned above is highlighted in this work. They demonstrate that the transferred films can satisfy high-performance power electronics, molecular sensors, and high-speed modulators for the next generation applications beyond 5G. Moreover, flexible composite structures prepared by the wafer bonding and de-bonding methods towards wearable electronics are reported. Finally, the outlooks and conclusions about the further development of heterogeneous structures that need to be achieved by the wafer bonding technology are discussed.

9.
J Ethnopharmacol ; 269: 113718, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33352239

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ferula sinkiangensis K. M. Shen is a traditional Chinese medicine that has a variety of pharmacological properties relevant to neurological disorders and inflammations. Kellerin, a novel compound extracted from Ferula sinkiangensis, exerts a strong anti-neuroinflammatory effect by inhibiting microglial activation. Microglial activation plays a vital role in ischemia-induced brain injury. However, the potential therapeutic effect of kellerin on focal cerebral ischemia is still unknown. AIM OF THE STUDY: To explore the effect of kellerin on cerebral ischemia and clarify its possible mechanisms, we applied the middle cerebral artery occlusion (MCAO) model and the LPS-activated microglia model in our study. MATERIALS AND METHODS: Neurological outcome was examined according to a 4-tiered grading system. Brain infarct size was measured using TTC staining. Brain edema was calculated using the wet weight minus dry weight method. Neuron damage and microglial activation were observed by immunofluorescence in MCAO model in rats. In in vitro studies, microglial activation was examined by flow cytometry and the viability of neuronal cells cultured in microglia-conditioned medium was measured using MTT assay. The levels of pro-inflammatory cytokines were measured by qRT-PCR and ELISA. The proteins involved in NF-κB signaling pathway were determined by western blot. Intracellular ROS was examined using DCFH-DA method and NADPH oxidase activity was measured using the NBT assay. RESULTS: We found that kellerin improved neurological outcome, reduced brain infarct size and decreased brain edema in MCAO model in rats. Under the pathologic conditions of focal cerebral ischemia, kellerin alleviated neuron damage and inhibited microglial activation. Moreover, in in vitro studies of LPS-stimulated BV2 cells kellerin protected neuronal cells from being damaged by inhibiting microglial activation. Kellerin also reduced the levels of pro-inflammatory cytokines, suppressed the NF-κB signaling pathway, and decreased ROS generation and NADPH oxidase activity. CONCLUSIONS: Our discoveries reveal that the neuroprotective effects of kellerin may largely depend on its inhibitory effect on microglial activation. This suggests that kellerin could serve as a novel anti-inflammatory agent which may have therapeutic effects in ischemic stroke.


Assuntos
Anti-Inflamatórios/farmacologia , Isquemia Encefálica/tratamento farmacológico , Ferula/química , Infarto da Artéria Cerebral Média/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Animais , Anti-Inflamatórios/uso terapêutico , Edema Encefálico/tratamento farmacológico , Isquemia Encefálica/etiologia , Isquemia Encefálica/patologia , Linhagem Celular Transformada , Linhagem Celular Tumoral , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Infarto da Artéria Cerebral Média/etiologia , Infarto da Artéria Cerebral Média/patologia , Inflamação/tratamento farmacológico , Lipopolissacarídeos/toxicidade , Camundongos , Microglia/efeitos dos fármacos , Microglia/patologia , NADPH Oxidases/antagonistas & inibidores , Subunidade p50 de NF-kappa B/antagonistas & inibidores , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Extratos Vegetais/uso terapêutico , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
10.
Sci Bull (Beijing) ; 66(12): 1176-1185, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-36654355

RESUMO

Ion mobility analysis is a well-known analytical technique for identifying gas-phase compounds in fast-response gas-monitoring systems. However, the conventional plasma discharge system is bulky, operates at a high temperature, and inappropriate for volatile organic compounds (VOCs) concentration detection. Therefore, we report a machine learning (ML)-enhanced ion mobility analyzer with a triboelectric-based ionizer, which offers good ion mobility selectivity and VOC recognition ability with a small-sized device and non-strict operating environment. Based on the charge accumulation mechanism, a multi-switched manipulation triboelectric nanogenerator (SM-TENG) can provide a direct current (DC) bias at the order of a few hundred, which can be further leveraged as the power source to obtain a unique and repeatable discharge characteristic of different VOCs, and their mixtures, with a special tip-plate electrode configuration. Aiming to tackle the grand challenge in the detection of multiple VOCs, the ML-enhanced ion mobility analysis method was successfully demonstrated by extracting specific features automatically from ion mobility spectrometry data with ML algorithms, which significantly enhance the detection ability of the SM-TENG based VOC analyzer, showing a portable real-time VOC monitoring solution with rapid response and low power consumption for future internet of things based environmental monitoring applications.

11.
Mol Nutr Food Res ; 65(2): e2000711, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33280250

RESUMO

SCOPE: In the present study, effect of pterostilbene on ß-amyloid 1-42 (Aß1-42 ) induced cognitive impairment in mice is investigated and explored its possible mechanism of action. METHODS AND RESULTS: The behavior results show that pterostilbene alleviated Aß1-42 -induces cognitive dysfunction assessed using the Y-maze test, novel object recognition task, Morris water maze test, and passive avoidance test. Pterostilbene alleviates neuron loss and accumulation of reactive oxygen species in Aß1-42 treated mouse brain. Additionally, pterostilbene promotes nuclear factor-E2 p45-related factor 2 (Nrf2) nuclear translocation and enhance the transcription and expression of antioxidant genes such as heme oxygenase-1 and superoxide dismutase both in vivo and in vitro. Nrf2 inhibitor ML385 reverses the antioxidant function of pterostilbene in SH-SY5Y cells. Nrf2 is the master regulator of oxidative homeostasis and can be activated by substrate adaptor sequestosome-1 (also named p62). Pterostilbene promotes the binding of Kelch-like ECH-associated protein 1 and p62, which enhanced activation of Nrf2. CONCLUSION: The present study reports that pterostilbene alleviated Aß1-42 -induces cognitive dysfunction in mice. The mechanism of pterostilbene can be associated to the inhibition of oxidative stress through the Nrf2 signaling pathway.


Assuntos
Disfunção Cognitiva/tratamento farmacológico , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estilbenos/farmacologia , Doença de Alzheimer/etiologia , Peptídeos beta-Amiloides/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Humanos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/fisiologia , Fragmentos de Peptídeos/toxicidade , Transdução de Sinais/efeitos dos fármacos
12.
ACS Nano ; 14(9): 12159-12172, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32812748

RESUMO

As one of the most effective surface-enhanced infrared absorption (SEIRA) techniques, metal-insulator-metal structured metamaterial perfect absorbers possess an ultrahigh sensitivity and selectivity in molecular infrared fingerprint detection. However, most of the localized electromagnetic fields (i.e., hotspots) are confined in the dielectric layer, hindering the interaction between analytes and hotspots. By replacing the dielectric layer with the nanofluidic channel, we develop a sapphire (Al2O3)-based mid-infrared (MIR) hybrid nanofluidic-SEIRA (HN-SEIRA) platform for liquid sensors with the aid of a low-temperature interfacial heterogeneous sapphire wafer direct bonding technique. The robust atomic bonding interface is confirmed by transmission electron microscope observation. We also establish a design methodology for the HN-SEIRA sensor using coupled-mode theory to carry out the loss engineering and experimentally validate its feasibility through the accurate nanogap control. Thanks to the capillary force, liquid analytes can be driven into sensing hotspots without external actuation systems. Besides, we demonstrate an in situ real-time dynamic monitoring process for the acetone molecular diffusion in deionized water. A small concentration change of 0.29% is distinguished and an ultrahigh sensitivity (0.8364 pmol-1 %) is achieved. With the aid of IR fingerprint absorption, our HN-SEIRA platform brings the selectivity of liquid molecules with similar refractive indexes. It also resolves water absorption issues in traditional IR liquid sensors thanks to the sub-nm long light path. Considering the wide transparency window of Al2O3 in MIR (up to 5.2 µm), the HN-SEIRA platform covers more IR absorption range for liquid sensing compared to fused glass commonly used in micro/nanofluidics. Leveraging the aforementioned advantages, our work provides insights into developing a MIR real-time liquid sensing platform with intrinsic IR fingerprint selectivity, label-free ultrahigh sensitivity, and ultralow analyte volume, demonstrating a way toward quantitative molecule identification and dynamic analysis for the chemical and biological reaction processes.

13.
Food Funct ; 11(6): 5432-5445, 2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-32490497

RESUMO

Ischemic stroke is a severe neurological disease without known effective therapy. Microglia-mediated neuroinflammation plays an important role in ischemic stroke. Therefore, finding a safe and effective microglial activation inhibitor might lead to an effective therapeutic strategy against ischemic stroke. In this project, our goal was to explore both the mechanism and effect of pterostilbene in MCAO/R rats. The potential effect of pterostilbene on ischemic stroke was tested using MCAO/R rats and its effect on microglial activation was tested in LPS-stimulated BV-2 cells. In vivo, pterostilbene decreased the neurological scores, brain water content and infarct volume in MCAO/R rats. Pterostilbene increased the number of mature neurons, decreased the number of activated microglia, and reduced iNOS and IL-1ß mRNA expression. Pterostilbene inhibited phosphorylated-IκBα expression, thus promoting IκBα expression and inhibiting ROS overexpression. In vitro, pterostilbene inhibited the expression of inflammatory cytokines and suppressed NAPDH activity as well as activation of both the NF-κB pathway and ROS production. To our knowledge, our study is the first to demonstrate that pterostilbene-mediated alleviation of cerebral ischemia and reperfusion injury in rats may be correlated with the inhibition of the ROS/NF-κB-mediated inflammatory pathway in microglia, indicating the potential for the use of pterostilbene as a candidate therapeutic compound for ischemic stroke.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Ativação de Macrófagos/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Estilbenos/farmacologia , Animais , Encéfalo/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Regulação da Expressão Gênica , Inflamação/tratamento farmacológico , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Masculino , Microglia/efeitos dos fármacos , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/tratamento farmacológico
14.
Phytother Res ; 34(9): 2258-2274, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32207202

RESUMO

Ischemic stroke is a global disease with high disability and mortality rates. Cognitive impairment is one of the major clinical features of ischemic stroke, and microglia-mediated inflammation has been shown to be an important contributor to the pathogenesis of ischemic stroke. Kellerin, extracted from Ferula sinkiangensis, was previously shown to inhibit microglial activation and exert a strong anti-neuroinflammatory effect. However, there is no report of the potential therapeutic effect of kellerin on ischemic stroke by targeting microglial cells. In this study, we wanted to examine the effects of kellerin on ischemic stroke in the bilateral common carotid artery occlusion (BCCAO) model and the lipopolysaccharide (LPS)-activated microglia model. We found that kellerin alleviated cognitive impairment, decreased neuronal loss, suppressed microglial activation, and transformed microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype in BCCAO mice. Moreover, in in vitro studies, we found that kellerin regulated microglial polarization and inhibited the NLRP3 and MAPK signaling pathways after LPS treatment. These findings provide a new understanding of the function of kellerin in ischemic stroke, and suggest that kellerin could be a potential therapeutic agent for the treatment of ischemic stroke.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Disfunção Cognitiva/tratamento farmacológico , Lipopolissacarídeos/uso terapêutico , Memória de Curto Prazo/efeitos dos fármacos , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Lipopolissacarídeos/farmacologia , Masculino , Camundongos
15.
J Neuroinflammation ; 16(1): 281, 2019 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-31883536

RESUMO

BACKGROUND: Microglia, the mononuclear immune cells of the central nervous system (CNS), are essential for the maintenance of CNS homeostasis. BAP31, a resident and ubiquitously expressed protein of the endoplasmic reticulum, serves as a sorting factor for its client proteins, mediating the subsequent export, retention, and degradation or survival. Recently, BAP31 has been defined as a regulatory molecule in the CNS, but the function of BAP31 in microglia has yet to be determined. In the present study, we investigated whether BAP31 is involved in the inflammatory response of microglia. METHODS: This study used the BV2 cell line and BAP31 conditional knockdown mice generated via the Cre/LoxP system. A BAP31 knockdown experiment was performed to elucidate the role of BAP31 in the endogenous inflammatory cytokine production by microglial BV2 cells. A mouse model of lipopolysaccharide (LPS)-induced cognitive impairment was established to evaluate the neuroprotective effect of BAP31 against neuroinflammation-induced memory deficits. Behavioral alterations were assessed with the open field test (OFT), Y maze, and Morris water maze. The activation of microglia in the hippocampus of mice was observed by immunohistochemistry. Western blot, enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining, and reverse transcription quantitative real-time polymerase chain reaction (RT-PCR) were used to clarify the mechanisms. RESULTS: BAP31 deficiency upregulates LPS-induced proinflammatory cytokines in BV2 cells and mice by upregulating the protein level of IRAK1, which in turn increases the translocation and transcriptional activity of NF-κB p65 and c-Jun, and moreover, knockdown of IRAK1 or use of an IRAK1 inhibitor reverses these functions. In the cognitive impairment animal model, the BAP31 knockdown mice displayed increased severity in memory deficiency accompanied by an increased expression of proinflammatory factors in the hippocampus. CONCLUSIONS: These findings indicate that BAP31 may modulate inflammatory cytokines and cognitive impairment induced by neuroinflammation through IRAK1, which demonstrates that BAP31 plays an essential role in microglial inflammation and prevention of memory deficits caused by neuroinflammation.


Assuntos
Encefalite/metabolismo , Inflamação/metabolismo , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Proteínas de Membrana/metabolismo , Microglia/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Citocinas/metabolismo , Encefalite/induzido quimicamente , Encefalite/patologia , Inflamação/induzido quimicamente , Inflamação/patologia , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Endogâmicos C57BL
16.
Bioorg Chem ; 91: 103175, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31398598

RESUMO

Modulating inflammatory responses after stroke can prevent brain injury and, therefore, improve neurological outcome. Stephania japonica (Thunb.) Miers is a Chinese folk medicine with the function of dispelling the "wind and blockage" in the human body according to the Chinese medicine theory, in which the symptoms of stroke are caused by the "wind and blockage" in the body. In this paper, we for the first time linked S. japonica to stroke by clarifying fifteen alkaloidal constituents including five undescribed (1-5) ones and screening out six hasubanan type alkaloids (1-4, 7, 15) that elicited stronger anti-neuroinflammatory activities than the positive drug. Moreover, the total alkaloid fraction (ASJ) with previously undescribed 3 as the main component was subject to the in vivo evaluation of the protective effect in the MCAO-induced brain injury. The results showed that ASJ exhibited potent protective effect against brain injury in the MCAO rat model. The results reported in this paper suggested that the hasubanan alkaloids from S. japonica would be an important molecular source for discovering novel therapeutic agents for neuroinflammation-related diseases, such as stroke diseases.


Assuntos
Alcaloides/farmacologia , Produtos Biológicos/farmacologia , Lesões Encefálicas/tratamento farmacológico , Infarto da Artéria Cerebral Média/complicações , Fármacos Neuroprotetores/farmacologia , Stephania/química , Alcaloides/química , Animais , Produtos Biológicos/química , Lesões Encefálicas/etiologia , Lesões Encefálicas/patologia , Infarto Cerebral/tratamento farmacológico , Infarto Cerebral/patologia , Masculino , Camundongos , Doenças do Sistema Nervoso/tratamento farmacológico , Doenças do Sistema Nervoso/patologia , Fármacos Neuroprotetores/química , Ratos , Ratos Sprague-Dawley
17.
Mol Nutr Food Res ; 63(20): e1801380, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31378007

RESUMO

SCOPE: The anti-neuroinflammatory effect of a novel quinolyl-substituted analogue of resveratrol (RV01) on lipopolysaccharide (LPS)-induced microglial activation is investigated, as well as the possible underlying mechanisms. METHODS AND RESULTS: Cell viability is measured using an MTT assay. Nitric oxide (NO) release is determined by nitrite assay. The interaction between RV01 and inducible nitric oxide synthase (iNOS) is studied using molecular docking. Free radical scavenging activity and reactive oxygen species (ROS) production are determined by DPPH reduction assay and DCFH-DA assay. Pretreatment with RV01 (1-30 µm) prior to LPS (1 µg mL-1 ) stimulation decreased NO release and iNOS expression without observable cytotoxicity. RV01 reduced the mRNA levels and secretion of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). RV01 also inhibited LPS-induced ROS production and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation. Furthermore, RV01 decreases the protein expression of toll-like receptor 4 (TLR4) and inhibits the LPS-induced activation of the mitogen-activated protein kinase (MAPK) and nuclear transcription factor-κB (NF-κB) signaling pathways. Additionally, conditioned medium from microglia co-treated with LPS and RV01 alleviates the death of SH-SY5Y cells induced by conditioned medium from activated N9 microglial cells. Lastly, a mouse neuroinflammation model is further used to confirm the effect of RV01 in vivo. CONCLUSION: These results show that RV01 suppresses microglia-mediated neuroinflammation and protects neurons from inflammatory damage, which indicates that RV01 has great potential as a nutritional preventive strategy for neuroinflammation-related diseases.


Assuntos
Inflamação/prevenção & controle , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Microglia/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Resveratrol/análogos & derivados , Animais , Células Cultivadas , Humanos , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , NADPH Oxidases/metabolismo , NF-kappa B/fisiologia , Óxido Nítrico/biossíntese , Espécies Reativas de Oxigênio/metabolismo , Resveratrol/farmacologia , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genética
18.
J Physiol Sci ; 69(3): 477-488, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30767122

RESUMO

Xanthoceraside, a novel triterpenoid saponin, has been found to attenuate learning and memory impairments in AD animal models. However, whether xanthoceraside has a positive effect on synaptic morphology remains unclear. Herein, we evaluated the effects of xanthoceraside on learning and memory impairments and the abnormalities of synaptic structure in APP/PS1 transgenic mice. The behavioral experiments demonstrated that xanthoceraside attenuated the imaginal memory and spatial learning impairments, and improved social interaction. Transmission electron microscopy and Golgi staining showed that xanthoceraside ameliorated synapse morphology abnormalities and dendritic spine density deficits, respectively. Western-blot analysis identified that xanthoceraside increased the expression of SYP and PSD95, activated BDNF/TrkB/MAPK/ERK and PI3K/Akt signaling pathways, meanwhile decreased the expression of RhoA, ROCK and Snk, increased the levels of SPAR, and activated the BDNF/TrkB/cofilin signaling pathway. Taken together, our study indicated that xanthoceraside improved cognitive function and protected both synaptic morphology and dendritic spine in APP/PS1 transgenic mice, which might be related in part to its activation in the BDNF/TrkB pathway.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Cognição/efeitos dos fármacos , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/prevenção & controle , Memória/efeitos dos fármacos , Saponinas/farmacologia , Sinapses/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/metabolismo , Modelos Animais de Doenças , Masculino , Transtornos da Memória/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transdução de Sinais/efeitos dos fármacos , Sinapses/metabolismo
19.
Phytomedicine ; 40: 10-19, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29496162

RESUMO

BACKGROUND: Tamarix species are well known as the main host plants of Herba Cistanches, a valuable Traditional Chinese Medicine. They are also traditional medicinal plants themselves and are used to treat spleen problems, leucoderma and ocular conditions. PURPOSE: The aim of the present study was to investigate the anti-inflammatory effect of Tamarix hohenackeri Bunge. METHODS: In the present study, BV-2 microglial cells were used and stimulated with lipopolysaccharide (LPS). Cell viability was tested using the MTT assay. The release of nitric oxide (NO) was determined using the Griess assay. The mRNA level of inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF-α), interleukin (IL)-1ß and IL-6 were investigated by quantitative real-time PCR (qRT-PCR). The protein levels of phosphorylated of IκBα, ERK and MEK, as well as the cytoplasmic and nuclear NF-κB p65 were tested by Western blot analysis. The translocation of the NF-κB p65 subunit from the cytosol to the nucleus was investigated by immunofluorescence staining. RESULTS: Ethyl acetate (EtOAc) extract of Tamarix hohenackeri Bunge significantly inhibited the release of NO. Phytochemical research was performed to produce 13 main constituents. Among them, compounds 6, 7, 10 and 13 were identified to be the effective components with anti-inflammatory activity. These compounds significantly inhibited the production of NO by LPS-activated BV-2 microglial cells. qRT-PCR showed that compounds 6 and 7 significantly suppressed the LPS-induced transcription of genes encoding pro-inflammatory mediators, including iNOS, TNF-α, IL-1ß and IL-6. Western blot analysis showed that compound 7 inhibited the LPS-induced phosphorylation of IκBα and antagonized the LPS-induced reduction of cytoplasmic NF-κB p65 and the increase of nuclear NF-κB p65. Immunofluorescence staining showed that nuclear translocation of NF-κB p65 was suppressed by compound 7. Western blot analysis showed that compound 7 inhibited the LPS-induced phosphorylation of ERK and MEK. CONCLUSION: The present study revealed, for the first time, the effective anti-inflammatory agents from T. Hohenackeri. Compound 7 exerted potent anti-inflammatory effects and its underlying mechanism may be associated with its capacity to inhibit NF-κB signaling pathway and the MEK/ERK activation in activated microglia. The compound may be potential candidate therapeutic agent for neurodegenerative diseases.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Inflamação/tratamento farmacológico , Microglia/efeitos dos fármacos , Tamaricaceae/química , Animais , Anti-Inflamatórios não Esteroides/química , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas I-kappa B/metabolismo , Inflamação/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Microglia/patologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Plantas Medicinais/química , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
20.
RSC Adv ; 8(21): 11528-11535, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35542819

RESUMO

Direct bonding is an attractive technique for joining two mirror polished surfaces without any intermediate materials. Vacuum ultraviolet (VUV) irradiation is an effective way for cleaning surfaces as well as increasing hydrophilicity with less surface damage. However, its applications for the direct bonding of silicon and quartz glasses have seldom been explored. Therefore, in this paper, a vacuum ultraviolet/ozone (VUV/O3) activated direct bonding method for Si/Si and quartz/quartz was developed. A defect-free interface with high bonding strength was achieved after a low-temperature annealing process at 200 °C. According to water contact angle, Raman spectroscopy, atomic force microscopy, and transmission electron microscopy measurements, we demonstrated an understanding of the beneficial surface treatments from VUV irradiation. Then two models for Si/Si and quartz/quartz bonding were established separately based on low-temperature water stress corrosion. Our studies found that the increase of surface roughness with the extension of VUV irradiation time was attributed to the oxide asperities generated on the irradiated surfaces, which possessed strong deformability under the water stress corrosion effect. The excellent bonding benefits from the saturated silanol groups formed on the VUV irradiated surfaces and the positive effects of the interfacial water on the gap closure during the annealing process.

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