Publications by authors named "Yoshimasa Nakamura"

Abscisic acid (ABA) signaling in stomatal guard cells is crucial for plants to cope with abiotic stress condition. Pyrabactin is a synthetic agonist of ABA that has a selective affinity to limited isoforms of ABA receptors. Here we investigated the differential utilization of downstream signaling events in guard cell ABA signaling under specific receptor isoforms taking advantage of pyrabactin affinity.

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In guard cells, cytosolic Ca acts as a second messenger that mediates abscisic acid (ABA)- and pathogen-associated molecular pattern (PAMP)-induced stomatal closure. It was reported that Arabidopsis cyclic nucleotide-gated ion channel 2 (CNGC2) functions as hydrogen peroxide (HO)- and PAMP-activated Ca-permeable channels at the plasma membrane of mesophyll cells and mediates Ca-dependent PAMP-triggered immunity. In this study, we examined the role of CNGC2 in the regulation of stomatal movement because CNGC2 is also expressed in guard cells.

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Salt stress increases levels of reactive oxygen species (ROS), leading to a variety of damages in plants. Production of reactive carbonyl species (RCS) following ROS accumulation has been reported to be closely related to damage by salt stress. We investigated the effects of RCS scavengers, carnosine and pyridoxamine, on the inhibition of germination and seedling growth of Nipponbare (Oryza sativa L.

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Traditional Chinese Zhenjiang aromatic vinegar (Kozu) contains Fraglide-1 (FG1), a bioactive lactone with demonstrated peroxisome proliferator-activated receptor gamma (PPARγ) agonist and antioxidant activities. This study explored FG1's novel ability to antagonize the aryl hydrocarbon receptor (AhR) signaling pathway, which regulates artemin expression and contributes to itching and inflammation in atopic dermatitis. Through molecular docking simulations and cell-based assays in human keratinocytes, we demonstrated FG1's potent antagonistic activity against AhR signaling.

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Abscisic acid (ABA) induces stomatal closure in higher plants under drought stress. Glutathione (GSH) negatively regulates ABA-induced stomatal closure and reactive carbonyl species (RCS) play a role as signal mediators downstream of reactive oxygen species production in ABA signaling pathway in Arabidopsis thaliana. Activation of slow (S-type) anion channels and inhibition of inward-rectifying potassium ion (K) channels in the plasma membrane are essential for ABA-induced stomatal closure.

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Myrosinase, referred to as thioglucoside glucohydrolase (TGG), plays a crucial role in plant physiology through catalyzing the hydrolysis of glucosinolates into bioactive isothiocyanates. In Arabidopsis thaliana, the myrosinases TGG1 and TGG2 are essential for abscisic acid- and methyl jasmonate-induced stomata closure. Allyl isothiocyanate (AITC), one of myrosinase products, triggers stomatal closure in A.

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An elicitor, chitosan (CHT), induces stomatal closure in plants, which is accompanied by salicylhydroxamic acid (SHAM)-sensitive peroxidases-mediated reactive oxygen species (ROS) production in guard cells. Reactive carbonyl species (RCS) function downstream of ROS in abscisic acid (ABA) and methyl jasmonate (MeJA) signalling in guard cells. However, the involvement of RCS in CHT-induced stomatal closure is still unknown.

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Heat treatment is the most common processing method in Apostichopus japonicus (A. japonicus) processing. However, improper heat treatment can lead to the degradation of protein.

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This research endeavored to engineer robust delivery matrices for bioactives, specifically benzyl isothiocyanate (BITC), by harnessing the synergistic covalent and non-covalent interactions between fish skin gelatin (FSG) and proanthocyanidins (PC) to synthesize novel composite emulsions. The objective was to delineate the influence of these molecular interactions on the emulsion's structural integrity and stability, which are pivotal for the efficacious encapsulation and controlled release of BITC. Employing a suite of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy, and contact angle measurements, the study delineated the predominant molecular forces at play within the FSG-PC complex, identifying electrostatic and hydrophobic interactions as the cornerstones of this interaction.

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GUARD CELL HYDROGEN PEROXIDE-RESISTANT1 (GHR1), a leucine-rich repeat receptor-like kinase, is involved in abscisic acid (ABA)-induced stomatal closure. We investigated the role of GHR1 in reactive oxygen species (ROS) signaling for ABA-induced stomatal closure. ABA induced ROS production in wild type (WT) and the ghr1 of Arabidopsis thaliana.

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Recently, the increasing incidence of malignant melanoma has become a major public health concern owing to its poor prognosis and impact on quality of life. Consuming foods with potent antitumor compounds can help prevent melanoma and maintain skin health. Fucoxanthin (FX), a naturally occurring carotenoid found in brown algae, possesses antitumor properties.

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It is still unclear whether or how quercetin influences the toxic events induced by acetaldehyde in hepatocytes, though quercetin has been reported to mitigate alcohol-induced mouse liver injury. In this study, we evaluated the modulating effect of quercetin on the cytotoxicity induced by acetaldehyde in mouse hepatoma Hepa1c1c7 cells, the frequently used cellular hepatocyte model. The pretreatment with quercetin significantly inhibited the cytotoxicity induced by acetaldehyde.

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Fucoxanthin (FX), a non-provitamin-A carotenoid, is a well-known major xanthophyll contained in edible brown algae. The nanoencapsulation of FX was motivated due to its multiple activities. Here, nano-encapsulated-FX (nano-FX) was prepared according to our early method by using whey protein and flaxseed gum as the biomacromolecule carrier material, then in vivo antitumor effect and mechanism of nano-FX on xenograft mice were investigated.

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Plants often face high salinity as a significant environmental challenge with roots being the first responders to this stress. Maintaining K/Na ratio within plant cells is crucial for survival, as the intracellular K level decreases and the intracellular Na level increases under saline conditions. However, knowledge about the molecular regulatory mechanisms of K loss in response to salt stress through outward-rectifying K channels in plants is largely unknown.

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Protective effect of quercetin against acetaldehyde was evaluated using the cultured hepatocyte models with aldehyde dehydrogenase (ALDH) isozyme deficiency (aldh2-kd and aldh1a1-kd). The quercetin-induced cytoprotection against acetaldehyde in the ALDH1A1-deficient mutant (aldh1a1-kd) was weaker than that in the wild type. Furthermore, quercetin did not enhance the ALDH activity in aldh1a1-kd cells, suggesting that ALDH1A1 is involved in quercetin-induced cytoprotection.

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Chitosan (CHT) is a deacylated derivative of chitin and improves growth and yield performance, activates defensive genes, and also induces stomatal closure in plants. Glutathione (GSH) has significant functions in the growth, development, defense systems, signaling, and gene expression. GSH negatively regulates abscisic acid-, methyl jasmonate-, and salicylic acid-induced stomatal closure.

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Apostichopus japonicus (A. japonicus) has rich nutritional value and is an important economic crop. Due to its rich endogenous enzyme system, fresh A.

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The aim of this study is to investigate the modulating effect of coexisting food components on the absorption and metabolism of quercetin and blood plasma antioxidant potentials. The combination of quercetin with α-tocopherol (αT), cellulose, or a commercially available vegetable beverage containing αT and dietary fiber was orally administered to mice. Compared to the single administration of quercetin aglycone, the coadministration of αT with quercetin significantly increased the plasma quercetin concentration at 0.

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In atopic dermatitis (AD), nerves are abnormally stretched near the surface of the skin, making it sensitive to itching. Expression of neurotrophic factor Artemin (ARTN) involved in such nerve stretching is induced by the xenobiotic response (XRE) to air pollutants and UV radiation products. Therefore, AD can be monitored by the XRE response.

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Article Synopsis
  • The study explores how fucoxanthin (FX), a marine dietary compound, can lower oxidative stress in retinal Müller cells caused by UVB exposure.
  • It highlights that digestive processes can affect how well FX is absorbed, leading to the examination of FX's digestion products (FX-ID) and their protective effects on cells.
  • Findings indicate that FX-ID reduces harmful reactive oxygen species and cell death, while also impacting key signaling pathways related to inflammation and metabolism, potentially aiding in the prevention of retinal disorders.
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Dihydroxyacetone (DHA) occurs in wide-ranging organisms, including plants, and can undergo spontaneous conversion to methylglyoxal (MG). While the toxicity of MG to plants is well-known, the toxicity of DHA to plants remains to be elucidated. We investigated the effects of DHA and MG on Arabidopsis.

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To retard the protein degradation during sea cucumber processing, polyphenol extracts from Ascophyllum nodosum (PhE) was used as a potential antioxidant to maintain the structural integrity of sea cucumber body wall. Accordingly, the protection effects of PhE (0, 0.5, 1.

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Since brown rice extract is a rich source of biologically active compounds, the present study is aimed to quantify the major compounds in brown rice and to compare their cytoprotective potential against oxidative stress. The content of the main hydrophobic compounds in brown rice followed the order of cycloartenyl ferulate (CAF) (89.00 ± 8.

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3,4-Dihydroxyphenylacetic acid (DOPAC) and 3-hydroxyphenylacetic acid (OPAC) are the predominant catabolites of quercetin glycosides, such as quercetin 4'--β-glucoside from the onion, produced by intestinal microbiota. Although each catabolite has been reported to protect the cells from acetaldehyde-induced cytotoxicity, the effect of their combination remains to be clarified. The purpose of this study was to determine whether the combination of DOPAC and OPAC enhances the resistance against the acetaldehyde-induced oxidative stress in the cultured hepatocytes.

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Background: Fish skin gelatin (FSG) and luteolin (LUT) were used as composite emulsifiers, and benzyl isothiocyanate (BITC) was used as a model of nutrient delivery to construct a stable emulsion. The storage stability of the FSG-LUT emulsion and its effect on BITC release were investigated both in vitro and ex vivo.

Results: LUT can quench FSG fluorophores statically and form a stable complex through hydrogen bonding and hydrophobic interactions.

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