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1.
Neuroimage ; 243: 118541, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34478824

RESUMEN

Resting-state functional magnetic resonance imaging (fMRI) has drastically expanded the scope of brain research by advancing our knowledge about the topologies, dynamics, and interspecies translatability of functional brain networks. Several databases have been developed and shared in accordance with recent key initiatives in the rodent fMRI community to enhance the transparency, reproducibility, and interpretability of data acquired at various sites. Despite these pioneering efforts, one notable challenge preventing efficient standardization in the field is the customary choice of anisotropic echo planar imaging (EPI) schemes with limited spatial coverage. Imaging with anisotropic resolution and/or reduced brain coverage has significant shortcomings including reduced registration accuracy and increased deviation in brain feature detection. Here we proposed a high-spatial-resolution (0.4 mm), isotropic, whole-brain EPI protocol for the rat brain using a horizontal slicing scheme that can maintain a functionally relevant repetition time (TR), avoid high gradient duty cycles, and offer unequivocal whole-brain coverage. Using this protocol, we acquired resting-state EPI fMRI data from 87 healthy rats under the widely used dexmedetomidine sedation supplemented with low-dose isoflurane on a 9.4 T MRI system. We developed an EPI template that closely approximates the Paxinos and Watson's rat brain coordinate system and demonstrated its ability to improve the accuracy of group-level approaches and streamline fMRI data pre-processing. Using this database, we employed a multi-scale dictionary-learning approach to identify reliable spatiotemporal features representing rat brain intrinsic activity. Subsequently, we performed k-means clustering on those features to obtain spatially discrete, functional regions of interest (ROIs). Using Euclidean-based hierarchical clustering and modularity-based partitioning, we identified the topological organizations of the rat brain. Additionally, the identified group-level FC network appeared robust across strains and sexes. The "triple-network" commonly adapted in human fMRI were resembled in the rat brain. Through this work, we disseminate raw and pre-processed isotropic EPI data, a rat brain EPI template, as well as identified functional ROIs and networks in standardized rat brain coordinates. We also make our analytical pipelines and scripts publicly available, with the hope of facilitating rat brain resting-state fMRI study standardization.


Asunto(s)
Encéfalo/diagnóstico por imagen , Imagen Eco-Planar/métodos , Animales , Mapeo Encefálico/métodos , Análisis por Conglomerados , Procesamiento de Imagen Asistido por Computador/métodos , Isoflurano , Masculino , Ratas , Reproducibilidad de los Resultados
2.
Gerontology ; 64(6): 562-575, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30138913

RESUMEN

BACKGROUND: Ginseng has been used to improve brain function and increase longevity. However, little is known about the ingredients of ginseng and molecular mechanisms of its anti-brain aging effects. Gintonin is a novel exogenous ginseng-derived lysophosphatidic acid (LPA) receptor ligand; LPA and LPA1 receptors are involved in adult hippocampal neurogenesis. D-galactose (D-gal) is used to induce brain -aging in animal models because long-term treatment with D-gal facilitates hippocampal aging in experimental adult animals by decreasing hippocampal neurogenesis and inducing learning and memory dysfunction. OBJECTIVE: To investigate the protective effects of gintonin on D-gal-induced hippocampal senescence, impairment of long-term potentiation (LTP), and memory dysfunction. METHODS: Brain hippocampal aging was induced by D-gal administration (150 mg/kg/day, s.c.; 10 weeks). From the 7th week, gintonin (50 or 100 mg/kg/day, per os) was co-administered with D-gal for 4 weeks. We performed histological analyses, LTP measurements, and object location test. RESULTS: Co-administration of gintonin ameliorated D-gal-induced reductions in hippocampal Ki67-immunoreactive proliferating cells, doublecortin-immunoreactive neuroblasts, 5-bromo-2'-deoxyuridine-incorporating NeuN-immunoreactive mature neurons, and LPA1 receptor expression. Co-administration of gintonin in D-gal-treated mice increased the expression of phosphorylated cyclic adenosine monophosphate response element binding protein in the hippocampal dentate gyrus. In addition, co-administration of gintonin in D-gal-treated mice enhanced LTP and restored the cognitive functions compared with those in mice treated with D-gal only. CONCLUSION: These results show that gintonin administration restores D-gal-induced memory deficits by enhancing hippocampal LPA1 receptor expression, LTP, and neurogenesis. Finally, the present study shows that gintonin exerts anti-brain aging effects that are responsible for alleviating brain aging-related dysfunction.


Asunto(s)
Senescencia Celular , Galactosa/metabolismo , Hipocampo , Potenciación a Largo Plazo/efectos de los fármacos , Trastornos de la Memoria , Extractos Vegetales/farmacología , Animales , Senescencia Celular/efectos de los fármacos , Senescencia Celular/fisiología , Modelos Animales de Enfermedad , Glicoproteínas/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Lisofosfolípidos/farmacología , Trastornos de la Memoria/tratamiento farmacológico , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/fisiopatología , Ratones , Neurogénesis/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/fisiología , Receptores del Ácido Lisofosfatídico/metabolismo , Resultado del Tratamiento
3.
Biol Pharm Bull ; 40(7): 1063-1070, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28674249

RESUMEN

Ginseng extract has been used for prevention of atopic dermatitis (AD) in experimental animal models. However, little is known about its active ingredients and the molecular mechanisms underlying its anti-AD effects. Recently, we isolated a unique lysophosphatidic acid (LPA) receptor ligand, gintonin, from ginseng. Gintonin, the glycolipoprotein fraction of ginseng, contains LPAs, mainly LPA C18 : 2 with other minor lysophospholipid components. A line of evidence showed that serum autotaxin (ATX) activity and level are significantly elevated in human AD patients compared to those in normal controls, which indicates that ATX may be involved in human AD. In a previous study, we demonstrated that gintonin exerted anti-inflammatory effects via inhibition of microglial activation and proinflammatory cytokine production by immune cells and that it strongly inhibited ATX activity. In this study, we investigated whether oral administration of the gintonin-enriched fraction (GEF) could ameliorate the symptoms of 2,4-dinitrofluorobenzene (DNFB)-induced AD in NC/Nga mice. We found that oral administration of GEF to DNFB-induced AD mice for 2 weeks reduced ear swelling and AD skin index. In addition, oral administration of GEF reduced the serum levels of immunoglobulin E, histamine, interleukin-4, and interferon-γ. Histological examination showed that oral administration of GEF attenuated skin inflammation and significantly reduced eosinophil and mast cell infiltration into the skin. Moreover, oral administration of GEF not only decreased serum ATX level but also reduced serum ATX activity. The present study shows that the anti-AD effects of ginseng might be attributed to GEF-induced anti-inflammatory activity and ATX regulation.


Asunto(s)
Dermatitis Atópica/tratamiento farmacológico , Modelos Animales de Enfermedad , Hidrolasas Diéster Fosfóricas/sangre , Extractos Vegetales/uso terapéutico , Administración Oral , Animales , Estudios de Casos y Controles , Dermatitis Atópica/inducido químicamente , Dermatitis Atópica/metabolismo , Dinitrofluorobenceno/administración & dosificación , Masculino , Ratones , Extractos Vegetales/administración & dosificación
4.
Biol Pharm Bull ; 39(2): 156-62, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26830477

RESUMEN

Lysophosphatidic acid (1-acyl-2-lyso-sn-glycero-3-phosphatidic acid; LPA) is a simple and minor phospholipid in plants. Plant LPAs are merely metabolic intermediates in de novo lipid synthesis in plant cell membranes or for glycerophospholipid storage. The production and metabolisms of LPAs in animals are also well characterized and LPAs have diverse cellular effects in animal systems; i.e., from brain development to wound healing through the activation of G protein-coupled LPA receptors. Recent studies show that various foodstuffs such as soybean, cabbage and seeds such as sesame and sunflower contain bioactive LPAs. Some LPAs are produced from phosphatidic acid during the digestion of foodstuff. In addition, herbal medicines such as corydalis tuber, and especially ginseng, contain large amounts of LPAs compared to foodstuffs. Herbal LPAs bind to cell surface LPA receptors in animal cells and exert their biological effects. Herbal LPAs elicit [Ca(2+)]i transient and are coupled to various Ca(2+)-dependent ion channels and receptor regulations via the activation of LPA receptors. They also showed beneficial effects of in vitro wound healing, in vivo anti-gastric ulcer, anti-Alzheimer's disease, autotaxin inhibition and anti-metastasis activity. Thus, herbal LPAs can be useful agents for human health. Humans can utilize exogenous plant-derived LPAs for preventive or therapeutic purposes if plant-derived LPAs are developed as functional foods or natural medicine targeting LPA receptors. This brief review article introduces the known rich sources of herbal LPAs and herbal LPA binding protein, describes their biological effects, and further addresses possible clinical applications.


Asunto(s)
Lisofosfolípidos/química , Lisofosfolípidos/farmacología , Plantas/metabolismo , Animales , Lisofosfolípidos/metabolismo , Estructura Molecular , Preparaciones de Plantas/química , Plantas/química
5.
Acta Crystallogr D Biol Crystallogr ; 71(Pt 5): 1039-50, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25945569

RESUMEN

Lysophosphatidic acid (LPA) is a phospholipid growth factor with myriad effects on biological systems. LPA is usually present bound to animal plasma proteins such as albumin or gelsolin. When LPA complexes with plasma proteins, it binds to its cognate receptors with higher affinity than when it is free. Recently, gintonin from ginseng was found to bind to LPA and to activate mammalian LPA receptors. Gintonin contains two components: ginseng major latex-like protein 151 (GLP) and ginseng ribonuclease-like storage protein. Here, the crystal structure of GLP is reported, which belongs to the plant Bet v 1 superfamily, and a model is proposed for how GLP binds LPA. Amino-acid residues of GLP recognizing LPA were identified using site-directed mutagenesis and isothermal titration calorimetry. The resulting GLP mutants were used to study the activation of LPA receptor-dependent signalling pathways. In contrast to wild-type GLP, the H147A mutant did not bind LPA, elicit intracellular Ca(2+) transients in neuronal cells or activate Ca(2+)-dependent Cl(-) channels in Xenopus oocytes. Based on these results, a mechanism by which GLP recognizes LPA and its requirement to activate G protein-coupled LPA receptors to elicit diverse biological responses were proposed.


Asunto(s)
Embrión de Mamíferos/metabolismo , Hipocampo/metabolismo , Lisofosfolípidos/metabolismo , Oocitos/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Animales , Calcio/metabolismo , Células Cultivadas , Electrofisiología , Embrión de Mamíferos/citología , Femenino , Hipocampo/citología , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Mutación/genética , Oocitos/citología , Proteínas de Plantas/genética , Conformación Proteica , Homología de Secuencia de Aminoácido , Transducción de Señal , Xenopus laevis/crecimiento & desarrollo , Xenopus laevis/metabolismo
6.
J Neurophysiol ; 113(5): 1493-500, 2015 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25505112

RESUMEN

Lysophosphatidic acid (LPA) is one of the well-characterized, ubiquitous phospholipid molecules. LPA exerts its effect by activating G protein-coupled receptors known as LPA receptors (LPARs). So far, LPAR signaling has been critically implicated during early development stages, including the regulation of synapse formation and the morphology of cortical and hippocampal neurons. In adult brains, LPARs seem to participate in cognitive as well as emotional learning and memory. Recent studies using LPAR1-deficient mice reported impaired performances in a number of behavioral tasks, including the hippocampus-dependent spatial memory and fear conditioning tests. Nevertheless, the effect of LPAR activation in the synaptic transmission of central synapses after the completion of embryonic development has not been investigated. In this study, we took advantage of a novel extracellular agonist for LPARs called gintonin to activate LPARs in adult brain systems. Gintonin, a recently identified active ingredient in ginseng, has been shown to activate LPARs and mobilize Ca(2+) in an artificial cell system. We found that the activation of LPARs by application of gintonin acutely enhanced both excitatory and inhibitory transmission in central synapses, albeit through tentatively distinct mechanisms. Gintonin-mediated LPAR activation primarily resulted in synaptic enhancement and an increase in neuronal excitability in a phospholipase C-dependent manner. Our findings suggest that LPARs are able to directly potentiate synaptic transmission in central synapses when stimulated exogenously. Therefore, LPARs could serve as a useful target to modulate synaptic activity under pathological conditions, including neurodegenerative diseases.


Asunto(s)
Encéfalo/metabolismo , Potenciales Postsinápticos Excitadores , Potenciales Postsinápticos Inhibidores , Extractos Vegetales/farmacología , Receptores del Ácido Lisofosfatídico/metabolismo , Sinapsis/metabolismo , Animales , Encéfalo/efectos de los fármacos , Encéfalo/fisiología , Calcio/metabolismo , Masculino , Extractos Vegetales/química , Ratas , Ratas Sprague-Dawley , Receptores del Ácido Lisofosfatídico/agonistas , Sinapsis/efectos de los fármacos , Sinapsis/fisiología , Fosfolipasas de Tipo C/metabolismo
7.
Biol Pharm Bull ; 38(10): 1631-7, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26424022

RESUMEN

Gintonin is a novel ginseng-derived G protein-coupled lysophosphatidic acid (LPA) receptor ligand. Gintonin elicits an [Ca(2+)]i transient in animal cells via activation of LPA receptors. In vitro studies have shown that gintonin regulates various calcium-dependent ion channels and receptors. In in vivo studies, gintonin elicits anti-Alzheimer's disease activity through the activation of the non-amyloidogenic pathway and anti-metastatic effects through the inhibition of autotaxin. However, a method for gintonin quantitation in ginseng has not been developed. In the present study, we developed an enzyme immunoassay (EIA) to measure gintonin. A monoclonal antibody was raised in a mouse using gintonin as the immunogen, and an indirect competitive EIA was used to measure gintonin. The working range was 0.01-10 µg per assay. The anti-gintonin monoclonal antibody did not cross-react with the ginsenosides Ra, Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, and Rg3 or with LPAs such as LPA C16:0, LPA C18:0, LPA C18:1, and LPA C18:2. Using a standard curve, we measured the amount of gintonin in various ginseng extract fractions. Interestingly, we only detected a little amount of gintonin in conventional hot water extracts of Korean red ginseng. However, we can measure gintonin after ethanol extraction of Korean red ginseng marc. Thus, gintonin can be extracted from ginseng with ethanol but not water, and the remaining Korean red ginseng marc can be used to obtain gintonin. These results indicate that the EIA with the anti-gintonin monoclonal antibody can be used to quantify gintonin in various ginseng preparations, including commercial ginseng products.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Técnicas para Inmunoenzimas , Extractos Vegetales/análisis , Extractos Vegetales/inmunología , Animales , Línea Celular Tumoral , Etanol/química , Peroxidasa de Rábano Silvestre , Ratones Endogámicos BALB C , Panax/química , Agua/química
8.
Biol Pharm Bull ; 37(4): 576-80, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24694604

RESUMEN

Resveratrol is found in grapes, red wine, and berries. Resveratrol has been known to have many beneficial health effects, such as anti-cancer, neuroprotective, anti-nociceptive, and life-prolonging effects. However, the single cellular mechanisms by which resveratrol acts are relatively unknown, especially in terms of possible regulation of receptors involved in synaptic transmission. The glycine receptor is an inhibitory ligand-gated ion channel involved in fast synaptic transmission in spinal cord. In the present study, we investigated the effect of resveratrol on human glycine receptor channel activity. Glycine α1 receptors were expressed in Xenopus oocytes and glycine receptor channel activity was measured using a two-electrode voltage clamp technique. Treatment with resveratrol alone had no effect on oocytes injected with H2O or on oocytes injected with glycine α1 receptor cRNA. In the oocytes injected with glycine α1 receptor cRNA, co- or pre-treatment of resveratrol with glycine inhibited the glycine-induced inward peak current (IGly) in a reversible manner. The inhibitory effect of resveratrol on IGly was also concentration dependent, voltage independent, and non-competitive. These results indicate that resveratrol regulates glycine receptor channel activity and that resveratrol-mediated regulation of glycine receptor channel activity is one of several cellular action mechanisms of resveratrol for pain regulation.


Asunto(s)
Potenciales de la Membrana/efectos de los fármacos , Receptores de Glicina/antagonistas & inhibidores , Estilbenos/farmacología , Animales , Relación Dosis-Respuesta a Droga , Conductividad Eléctrica , Glicina/antagonistas & inhibidores , Glicina/farmacología , Humanos , Oocitos , Receptores de Glicina/metabolismo , Resveratrol , Xenopus laevis
9.
bioRxiv ; 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38464010

RESUMEN

While deep brain stimulation (DBS) is widely employed for managing motor symptoms in Parkinson's disease (PD), its exact circuit mechanisms remain controversial. To identify the neural targets affected by therapeutic DBS in PD, we analyzed DBS-evoked whole brain activity in female hemi-parkinsonian rats using function magnetic resonance imaging (fMRI). We delivered subthalamic nucleus (STN) DBS at various stimulation pulse repetition rates using optogenetics, allowing unbiased examinations of cell-type specific STN feed-forward neural activity. Unilateral STN optogenetic stimulation elicited pulse repetition rate-dependent alterations of blood-oxygenation-level-dependent (BOLD) signals in SNr (substantia nigra pars reticulata), GP (globus pallidus), and CPu (caudate putamen). Notably, these manipulations effectively ameliorated pathological circling behavior in animals expressing the kinetically faster Chronos opsin, but not in animals expressing ChR2. Furthermore, mediation analysis revealed that the pulse repetition rate-dependent behavioral rescue was significantly mediated by optogenetically induced activity changes in GP and CPu, but not in SNr. This suggests that the activation of GP and CPu are critically involved in the therapeutic mechanisms of STN DBS.

10.
Biol Pharm Bull ; 36(5): 812-8, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23649337

RESUMEN

Ginsenosides is a low molecular weight substance found in ginseng as one of the active ingredients. Ginsenosides, like other herbal medicines, has a wide range of neuropharmacological actions including neuroprotective effects. The α9α10 nicotinic acetylcholine receptor is one of numerous nicotinic acetylcholine receptors that exists as a heteropentameric form in auditory hair cells of the cochlea. In this study, we report the effects of ginsenosides on rat α9α10 nicotinic acetylcholine receptor-mediated ion currents using the two-electrode voltage clamp technique. Treatment with acetylcholine evoked inward currents (IACh) in oocytes heterologously expressing the α9α10 nicotinic acetylcholine receptor. Ginsenosides blocked IACh in order of potency of Rg3> Rb2> CK>Re = Rg2> Rf>Rc> Rb1> Rg1 with reversible manners, and the blocking effect of Rg3 on IACh was same after pre-application than co-application of Rg3. The half maximal inhibitory concentration (IC50) of Rg3 was 39.6 ± 4.9 µm. Rg3-induced IACh inhibition was not affected by acetylcholine concentration and was independent of membrane holding potential. Although the inhibitory effect of Rg3 on IACh was abolished in oocytes expressing α9 subunit alone, indicating that the presence of α10 subunit might be required for Rg3-induced regulations of α9α10 nicotinic acetylcholine receptor channel activity. These results indicate that α10 subunit of α9α10 nicotinic acetylcholine receptor might play an important role in Rg3-induced regulation of the α9α10 nicotinic acetylcholine receptor.


Asunto(s)
Ginsenósidos/farmacología , Subunidades de Proteína/fisiología , Receptores Nicotínicos/fisiología , Animales , Femenino , Técnicas In Vitro , Oocitos/efectos de los fármacos , Oocitos/fisiología , Ratas , Xenopus laevis
11.
Korean J Physiol Pharmacol ; 17(2): 127-32, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23626474

RESUMEN

Ginsenosides, one of the active ingredients of Panax ginseng, show various pharmacological and physiological effects, and they are converted into compound K (CK) or protopanaxatriol (M4) by intestinal microorganisms. CK is a metabolite derived from protopanaxadiol (PD) ginsenosides, whereas M4 is a metabolite derived from protopanaxatriol (PT) ginsenosides. The γ-aminobutyric acid receptorC (GABAC) is primarily expressed in retinal bipolar cells and several regions of the brain. However, little is known of the effects of ginsenoside metabolites on GABAC receptor channel activity. In the present study, we examined the effects of CK and M4 on the activity of human recombinant GABAC receptor (ρ1) channels expressed in Xenopus oocytes by using a 2-electrode voltage clamp technique. In oocytes expressing GABAC receptor cRNA, we found that CK or M4 alone had no effect in oocytes. However, co-application of either CK or M4 with GABA inhibited the GABA-induced inward peak current (IGABA ). Interestingly, pre-application of M4 inhibited IGABA more potently than CK in a dose-dependent and reversible manner. The half-inhibitory concentration (IC50) values of CK and M4 were 52.1±2.3 and 45.7±3.9 µM, respectively. Inhibition of IGABA by CK and M4 was voltage-independent and non-competitive. This study implies that ginsenoside metabolites may regulate GABAC receptor channel activity in the brain, including in the eyes.

12.
Korean J Physiol Pharmacol ; 17(2): 175-80, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23626481

RESUMEN

Resveratrol is a phytoalexin found in grapes, red wine, and berries. Resveratrol has been known to have many beneficial health effects, such as anti-cancer, neuroprotective, anti-inflammatory, and life-prolonging effects. However, relatively little is known about the effects of resveratrol on the regulation of ligand-gated ion channels. We have previously reported that resveratrol regulates subsets of homomeric ligand-gated ion channels such as those of 5-HT3A receptors. The γ-aminobutyric acidC (GABAC) receptor is mainly expressed in retinal bipolar cells and plays an important role in visual processing. In the present study, we examined the effects of resveratrol on the channel activity of homomeric GABAC receptor expressed in Xenopus oocytes injected with cRNA encoding human GABAC ρ subunits. Our data show that the application of GABA elicits an inward peak current (IGABA ) in oocytes that express the GABAC receptor. Resveratrol treatment had no effect on oocytes injected with H2O or with GABAC receptor cRNA. Co-treatment with resveratrol and GABA inhibited IGABA in oocytes with GABAC receptors. The inhibition of IGABA by resveratrol was in a reversible and concentration-dependent manner. The IC50 of resveratrol was 28.9±2.8 µM in oocytes expressing GABAC receptor. The inhibition of IGABA by resveratrol was in voltage-independent and non-competitive manner. These results indicate that resveratrol might regulate GABAC receptor expression and that this regulation might be one of the pharmacological actions of resveratrol on the nervous system.

13.
Korean J Physiol Pharmacol ; 17(3): 223-8, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23776399

RESUMEN

The calcium-activated K(+) (BKCa) channel is one of the potassium-selective ion channels that are present in the nervous and vascular systems. Ca(2+) is the main regulator of BKCa channel activation. The BKCa channel contains two high affinity Ca(2+) binding sites, namely, regulators of K(+) conductance, RCK1 and the Ca(2+) bowl. Lysophosphatidic acid (LPA, 1-radyl-2-hydroxy-sn-glycero-3-phosphate) is one of the neurolipids. LPA affects diverse cellular functions on many cell types through G protein-coupled LPA receptor subtypes. The activation of LPA receptors induces transient elevation of intracellular Ca(2+) levels through diverse G proteins such as Gαq/11, Gαi, Gα12/13, and Gαs and the related signal transduction pathway. In the present study, we examined LPA effects on BKCa channel activity expressed in Xenopus oocytes, which are known to endogenously express the LPA receptor. Treatment with LPA induced a large outward current in a reversible and concentration-dependent manner. However, repeated treatment with LPA induced a rapid desensitization, and the LPA receptor antagonist Ki16425 blocked LPA action. LPA-mediated BKCa channel activation was also attenuated by the PLC inhibitor U-73122, IP3 inhibitor 2-APB, Ca(2+) chelator BAPTA, or PKC inhibitor calphostin. In addition, mutations in RCK1 and RCK2 also attenuated LPA-mediated BKCa channel activation. The present study indicates that LPA-mediated activation of the BKCa channel is achieved through the PLC, IP3, Ca(2+), and PKC pathway and that LPA-mediated activation of the BKCa channel could be one of the biological effects of LPA in the nervous and vascular systems.

14.
ACS Appl Mater Interfaces ; 14(8): 10558-10565, 2022 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-35175718

RESUMEN

This study examines the effect of the annealing time of the Y2O3 passivation layer on the electrical performances and bias stabilities of sol-gel-deposited SnO2 thin-film transistors (TFTs). The environmental stabilities of SnO2 TFTs were examined. After optimizing the Y2O3 passivation layers in SnO2 TFTs, the field-effect mobility was 7.59 cm2/V•s, the VTH was 9.16 V, the subthreshold swing (SS) was 0.88 V/decade, and the on/off-current ratio was approximately 1 × 108. VTH shifts were only -0.18 and +0.06 V under negative and positive bias stresses, respectively. The SnO2 channel layer thickness and oxygen-vacancy concentration in SnO2, which determine the carrier concentration, were successfully tuned by controlling the annealing time of the Y2O3 passivation layers. An extremely thin Y2O3 passivation layer effectively blocked external molecules, thus affecting the device performance. The electrical performance was maximized in SnO2 TFTs using a 15 min-annealed Y2O3 passivation layer. In this TFT, the field-effect mobility was maximally retained and the bias and environmental stabilities were sustained over 90 days of air exposure.

15.
Materials (Basel) ; 15(5)2022 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-35269129

RESUMEN

Flexible indium tin oxide (ITO)/Y2O3/Ag resistive random access memory (RRAM) devices were successfully fabricated using a thermal-energy-free ultraviolet (UV)/ozone-assisted photochemical annealing process. Using the UV/ozone-assisted photochemical process, the organic residue can be eliminated, and thinner and smother Y2O3 films than those formed using other methods can be fabricated. The flexible UV/ozone-assisted photochemical annealing process-based ITO/Y2O3/Ag RRAM devices exhibited the properties of conventional bipolar RRAM without any forming process. Furthermore, the pure and amorphous-phase Y2O3 films formed via this process showed a decreased leakage current and an increased high-resistance status (HRS) compared with the films formed using other methods. Therefore, RRAM devices can be realized on plastic substrates using a thermal-energy-free UV/ozone-assisted photochemical annealing process. The fabricated devices exhibited a resistive window (ratio of HRS/low-resistance status (LRS)) of >104, with the HRS and LRS values remaining almost the same (i.e., limited deterioration occurred) for 104 s and up to 102 programming/erasing operation cycles.

16.
Materials (Basel) ; 15(5)2022 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-35269170

RESUMEN

Sol-gel-processed Y2O3 films were used as active channel layers for resistive random access memory (RRAM) devices. The fabricated ITO/Y2O3/Ag RRAM devices exhibited the properties of conventional bipolar memory devices. A triethylamine stabilizer with a high vapor pressure and low surface tension was added to realize the local electric field area. During drying and high-temperature post-annealing processes, the large convective flow enhanced the surface elevation, and the increased -OH groups accelerated the hydrolysis reaction and aggregation. These phenomena afforded Y2O3 films with an uneven surface morphology and an increased surface roughness. The increased roughness of the Y2O3 films attributable to the triethylamine stabilizer enhanced the local electrical field, improved device reliability, and achieved successful repetition of the switching properties over an extended period.

17.
J Anim Sci Technol ; 63(5): 1159-1168, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34796354

RESUMEN

Ovotransferrin (OTF), an egg protein known as transferrin family protein, possess strong antimicrobial and antioxidant activity. This is because OTF has two iron binding sites, so it has a strong metal chelating ability. The present study aimed to evaluate the improved immune-enhancing activities of OTF hydrolysates produced using bromelain, pancreatin, and papain. The effects of OTF hydrolysates on the production and secretion of pro-inflammatory mediators in RAW 264.7 macrophages were confirmed. The production of nitric oxide (NO) was evaluated using Griess reagent and the expression of inducible nitric oxide synthase (iNOS) were evaluated using quantitative real-time polymerase chain reaction (PCR). And the production of pro-inflammatory cytokines (tumor necrosis factor [TNF]-α and interleukin [IL]-6) and the phagocytic activity of macrophages were evaluated using an ELISA assay and neutral red uptake assay, respectively. All OTF hydrolysates enhanced NO production by increasing iNOS mRNA expression. Treating RAW 264.7 macrophages with OTF hydrolysates increased the production of pro-inflammatory cytokines and the phagocytic activity. The production of NO and pro-inflammatory cytokines induced by OTF hydrolysates was inhibited by the addition of specific mitogen-activated protein kinase (MAPK) inhibitors. In conclusion, results indicated that all OTF hydrolysates activated RAW 264.7 macrophages by activating MAPK signaling pathway.

18.
J Ginseng Res ; 45(3): 401-407, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34025133

RESUMEN

BACKGROUND: Gintonin is an exogenous ginseng-derived G-protein-coupled lysophosphatidic acid (LPA) receptor ligand. LPA induces in vitro morphological changes and migration through neuronal LPA1 receptor. Recently, we reported that systemic administration of gintonin increases blood-brain barrier (BBB) permeability via the paracellular pathway and its binding to brain neurons. However, little is known about the influences of gintonin on in vivo neuron morphology and migration in the brain. MATERIALS AND METHODS: We examined the effects of gintonin on in vitro migration and morphology using primary hippocampal neural precursor cells (hNPC) and in vivo effects of gintonin on adult brain neurons using real time microscopic analysis and immunohistochemical analysis to observe the morphological and locational changes induced by gintonin treatment. RESULTS: We found that treating hNPCs with gintonin induced morphological changes with a cell rounding following cell aggregation and return to individual neurons with time relapses. However, the in vitro effects of gintonin on hNPCs were blocked by the LPA1/3 receptor antagonist, Ki16425, and Rho kinase inhibitor, Y27632. We also examined the in vivo effects of gintonin on the morphological changes and migration of neurons in adult mouse brains using anti-NeuN and -neurofilament H antibodies. We found that acute intravenous administration of gintonin induced morphological and migrational changes in brain neurons. Gintonin induced some migrations of neurons with shortened neurofilament H in the cortex. The in vivo effects of gintonin were also blocked by Ki16425. CONCLUSION: The present report raises the possibility that gintonin could enter the brain and exert its influences on the migration and morphology of adult mouse brain neurons and possibly explains the therapeutic effects of neurological diseases behind the gintonin administration.

19.
Food Sci Anim Resour ; 40(6): 1001-1013, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33305284

RESUMEN

The formation of biofilms on the enamel surface of teeth by Streptococcus mutans is an important step in dental plaque formation, demineralization, and early caries because the biofilm is where other bacteria involved in dental caries attach, grow, and proliferate. The objectives of this study were to determine the effect of phosvitin (PSV) on the biofilm formation, exopolysaccharides (EPS) production, adherence activity of S. mutans, and the expression of genes related to the compounds essential for biofilm formation (quorum-sensing inducers and components of biofilm matrix) by S. mutans. PSV significantly reduced the biofilm-forming activity of S. mutans and increased the degradation of preformed biofilms by S. mutans. PSV inhibited the adherence activity of S. mutans by 31.9%-33.6%, and the production of EPS by 62%-65% depending upon the strains and the amount of PSV added. The expressions of genes regulating the production of EPS and the quorum-sensing-inducers (gtfA, gtfD, ftf, relA, vicR, brpA, and comDE) in all S. mutans strains were down-regulated by PSV, but gtfB was down-regulated only in S. mutans KCTC 5316. Therefore, the anti-biofilm-forming activity of PSV was accomplished through the inhibition of biofilm formation, adherence activity, and the production of quorum-sensing inducers and EPS by S. mutans.

20.
Artículo en Inglés | MEDLINE | ID: mdl-32013120

RESUMEN

Gintonin is a newly discovered ingredient of ginseng and plays an exogenous ligand for G protein-coupled lysophosphatidic acid receptors. We previously showed that gintonin exhibits diverse effects from neurotransmitter release to improvement of Alzheimer's disease-related cognitive dysfunctions. However, previous studies did not show whether gintonin has protective effects against environmental heavy metal. We investigated the effects of gintonin-enriched fraction (GEF) on methylmercury (MeHg)-induced neurotoxicity and learning and memory dysfunction and on organ MeHg elimination. Using hippocampal neural progenitor cells (hNPCs) and mice we examined the effects of GEF on MeHg-induced hippocampal NPC neurotoxicity, on formation of reactive oxygen species (ROS), and on in vivo learning and memory functions after acute MeHg exposure. Treatment of GEF to hNPCs attenuated MeHg-induced neurotoxicity with concentration- and time-dependent manner. GEF treatment inhibited MeHg- and ROS inducer-induced ROS formations. Long-term treatment of GEF also improved MeHg-induced learning and memory dysfunctions. Oral administration of GEF decreased the concentrations of MeHg in blood, brain, liver, and kidney. This is the first report that GEF attenuated MeHg-induced in vitro and in vivo neurotoxicities through LPA (lysophosphatidic acids) receptor-independent manner and increased organ MeHg elimination. GEF-mediated neuroprotection might achieve via inhibition of ROS formation and facilitation of MeHg elimination from body.


Asunto(s)
Disfunción Cognitiva/tratamiento farmacológico , Compuestos de Metilmercurio/toxicidad , Panax/química , Extractos Vegetales/uso terapéutico , Animales , Disfunción Cognitiva/inducido químicamente , Femenino , Ratones , Ratones Endogámicos C57BL , Receptores del Ácido Lisofosfatídico
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