Simple aromatic compounds containing propenone moiety show considerable dual COX/5-LOX inhibitory activities

For the development of safer anti-inflammatory agents, simple aromatic compounds containing propenone moiety were prepared and evaluated for their dual COX/5-LOX inhibitory activities. Among the 17 prepared compounds, most of the compounds exhibited considerable COX/5-LOX inhibitory activities. Especially compound C(15) showed the most significant dual COX/5-LOX inhibitory activity.     

Mechanism for antiplatelet effect of onion: AA release inhibition, thromboxane A(2)synthase inhibition and TXA(2)/PGH(2)receptor blockade

Antiplatelet actions of aqueous extract of onion were investigated in rat and human platelet. IC(50)values of onion extract for collagen-, thrombin-, arachidonic acid (AA)-induced aggregations and collagen-induced thromboxane A(2)(TXA(2)) formation were 0.17 +/- 0. 01, 0.23 + 0.03, 0.34 +/- 0.02 and 0.12 +/- 0.01 g/ml, respectively. [(3)H]-AA release induced by collagen (10 microg/ml) in rat platelet was decreased by onion compared to control (22.1 +/- 2.13 and 5.2 +/- 0.82% of total [(3)H]-AA incorporated, respectively). In fura-2 loaded platelets, the elevation of intracellular Ca(2+)concentration stimulated by collagen was inhibited by onion. Onion had no cytotoxic effect in platelet. Onion significantly inhibited TXA(2)synthase activity without influence on COX activity. Platelet aggregation induced by U46619, a stable TXA(2)mimetic, was inhibited by onion, indicating its antagonism for TXA(2)/PGH(2)receptor. These results suggest that the mechanism for antiplatelet effect of onion may, at least partly, involve AA release diminution, TXA(2)synthase inhibition and TXA(2)/PGH(2)receptor blockade.     

Attenuation of Experimental Colitis in Glutathione Peroxidase 1 and Catalase Double Knockout Mice through Enhancing Regulatory T Cell Function

Reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases including inflammatory bowel diseases (IBD). Meanwhile, several studies suggested the protective role of ROS in immune-mediated inflammatory diseases, and it was recently reported that dextran sodium sulfate (DSS)-induced colitis was attenuated in mice with an elevated level of ROS due to deficiency of peroxiredoxin II. Regulatory T cells (Tregs) are critical in the prevention of IBD and Treg function was reported to be closely associated with ROS level, but it has been investigated only in lowered levels of ROS so far. In the present study, in order to clarify the relationship between ROS level and Treg function, and their role in the pathogenesis of IBD, we investigated mice with an elevated level of ROS due to deficiency of both glutathione peroxidase (GPx)-1 and catalase (Cat) for the susceptibility of DSS-induced colitis in association with Treg function. The results showed that DSS-induced colitis was attenuated and Tregs were hyperfunctional in GPx1^−/− × Cat^−/− mice. In vivo administration of N-acetylcysteine (NAC) aggravated DSS-induced colitis and decreased Treg function to the level comparable to WT mice. Attenuated Th₁₇ cell differentiation from naïve CD4⁺ cells as well as impaired production of IL-6 and IL-17A by splenocytes upon stimulation suggested anti-inflammatory tendency of GPx1^−/− × Cat^−/− mice. Suppression of Stat3 activation in association with enhancement of indoleamine 2,3-dioxygenase and FoxP3 expression might be involved in the immunosuppressive mechanism of GPx1^−/− × Cat^−/− mice. Taken together, it is implied that ROS level is critical in the regulation of Treg function, and IBD may be attenuated in appropriately elevated levels of ROS.     

Isolation of a root-specific cDNA encoding a ns-LTP-like protein from the roots of bean (Phaseolus vulgaris L.) seedlings

A root-specific cDNA clone, PVR3, was isolated from a bean (Phaseolus vulgaris L.) root cDNA library by a differential screening procedure. The nucleotide sequence of PVR3 contains an open reading frame coding for an 11.14 kDa polypeptide of 102 amino acid residues; the first 25 amino acids correspond to the sequence characteristic of a signal peptide. Comparison of the deduced PVR3 polypeptide sequence with the polypeptide sequences of previously cloned genes indicates that PVR3 may encode a ns-LTP-like protein. Molecular modelling of the PVR3 protein predicts that it has a three-dimensional structure that is similar to the three-dimensional model determined from the maize ns-LTP. The PVR3 mRNA accumulated mainly in the roots of young seedlings. It can be detected at low levels in flowers, but it is not detected in other organs. Genomic Southern blot analysis indicates that the genomic DNA corresponding to PVR3 cDNA is encoded by a single gene or small gene family in the bean genome.     

Retarded Charge–Carrier Recombination in Photoelectrochemical Cells from Plasmon‐Induced Resonance Energy Transfer

N‐type metal oxides such as hematite (α‐Fe₂O₃) and bismuth vanadate (BiVO₄) are promising candidate materials for efficient photoelectrochemical water splitting; however, their short minority carrier diffusion length and restricted carrier lifetime result in undesired rapid charge recombination. Herein, a 2D arranged globular Au nanosphere (NS) monolayer array with a highly ordered hexagonal hole pattern (hereafter, Au array) is introduced onto the surface of photoanodes comprised of metal oxide films via a facile drying and transfer‐printing process. Through plasmon‐induced resonance energy transfer, the Au array provides a strong electromagnetic field in the near‐surface area of the metal oxide film. The near‐field coupling interaction and amplification of the electromagnetic field suppress the charge recombination with long‐lived photogenerated holes and simultaneously enhance the light harvesting and charge transfer efficiencies. Consequently, an over 3.3‐fold higher photocurrent density at 1.23 V versus reversible hydrogen electrode (RHE) is achieved for the Au array/α‐Fe₂O₃. Furthermore, the high versatility of this transfer printing of Au arrays is demonstrated by introducing it on the molybdenum‐doped BiVO₄ film, resulting in 1.5‐fold higher photocurrent density at 1.23 V versus RHE. The tailored metal film design can provide a potential strategy for the versatile application in various light‐mediated energy conversion and optoelectronic devices.     

The roles of LAT in platelet signaling induced by collagen, TxA2, or ADP

The work presented here demonstrates that platelets from mice lacking LAT (linker for the activation of T cells) show reversible aggregation in response to concentrations of collagen that cause TxA2/ADP-dependent irreversible aggregation of control platelets. The aggregation defect of the LAT-deficient platelets was shown to be the result of almost no TxA2 production and significantly diminished ADP secretion. In contrast, the LAT deficiency does not affect aggregation induced by high concentrations of collagen because that aggregation is not dependent on TxA2 and/or ADP. Even though ADP and TxA2 provide amplification signals for platelet activation in response to low concentrations of collagen, LAT-deficient platelets hyperaggregate to low levels of U46619, a TxA2 analog, or ADP. Though the mechanism(s) of costimulatory signals by collagen, ADP, and TxA2 remains unidentified, it is clear that LAT plays a positive role in collagen-induced, TxA2/ADP-dependent aggregation, and a negative role in TxA2 or ADP-induced platelet aggregation.     

Determination of the time transferring cells for astaxanthin production considering two-stage process of Haematococcus pluvialis cultivation

The two-stage culture system consisting of green vegetative growth and reddish inductive production stages has been widely accepted for the production of astaxanthin using Haematococcuspluvialis. However, little has been known about the appropriate cellular phase of H.pluvialis for transferring into the astaxanthin inductive conditions. In this study, we determined the optimal growth phase of H.pluvialis for transferring into the second production stage. Astaxanthin productivities were correlated with growth phases, as senescent green phases could increase more than 10-fold greater than juvenile green phases. Our results clearly demonstrated the appropriateness of the senescent vegetable cells for transferring into the production stage, due to the increased capacity to accumulate astaxanthin.     

QTLs for resistance to Phomopsis seed decay are associated with days to maturity in soybean (Glycine max)

Phomopsis seed decay (PSD), primarily caused by Phomopsis longicolla, is a major contributor to poor soybean seed quality and significant yield loss, particularly in early maturing soybean genotypes. However, it is not yet known whether PSD resistance is associated with early maturity. This study was conducted to identify quantitative trait loci (QTLs) for resistance to PSD and days to maturity using a recombinant inbred line (RIL) population derived from a cross between the PSD-resistant Taekwangkong and the PSD-susceptible SS2-2. Based on a genetic linkage map incorporating 117 simple sequence repeat markers, QTL analysis revealed two and three QTLs conferring PSD resistance and days to maturity, respectively, in the RIL population. Two QTLs (PSD-6-1 and PSD-10-2) for PSD resistance were identified in the intervals of Satt100–Satt460 and Sat_038–Satt243 on chromosomes 6 and 10, respectively. Two QTLs explained phenotypic variances in PSD resistance of 46.3 and 14.1 %, respectively. At the PSD-6-1 QTL, the PSD-resistant cultivar Taekwangkong contributed the allele with negative effect decreasing the infection rate of PSD and this QTL does not overlap with any previously reported loci for PSD resistance in other soybean genotypes. Among the three QTLs for days to maturity, two (Mat-6-2 and Mat-10-3) were located at positions similar to the PSD-resistance QTLs. The identification of the QTLs linked to both PSD resistance and days to maturity indicates a biological correlation between these two traits. The newly identified QTL for resistance to PSD associated with days to maturity in Taekwangkong will help improve soybean resistance to P. longicolla.     

Molecular Insights Into the Evolutionary Pathway of Vibrio cholerae O1 Atypical El Tor Variants

Pandemic V. cholerae strains in the O1 serogroup have 2 biotypes: classical and El Tor. The classical biotype strains of the sixth pandemic, which encode the classical type cholera toxin (CT), have been replaced by El Tor biotype strains of the seventh pandemic. The prototype El Tor strains that produce biotype-specific cholera toxin are being replaced by atypical El Tor variants that harbor classical cholera toxin. Atypical El Tor strains are categorized into 2 groups, Wave 2 and Wave 3 strains, based on genomic variations and the CTX phage that they harbor. Whole-genome analysis of V. cholerae strains in the seventh cholera pandemic has demonstrated gradual changes in the genome of prototype and atypical El Tor strains, indicating that atypical strains arose from the prototype strains by replacing the CTX phages. We examined the molecular mechanisms that effected the emergence of El Tor strains with classical cholera toxin-carrying phage. We isolated an intermediary V. cholerae strain that carried two different CTX phages that encode El Tor and classical cholera toxin, respectively. We show here that the intermediary strain can be converted into various Wave 2 strains and can act as the source of the novel mosaic CTX phages. These results imply that the Wave 2 and Wave 3 strains may have been generated from such intermediary strains in nature. Prototype El Tor strains can become Wave 3 strains by excision of CTX-1 and re-equipping with the new CTX phages. Our data suggest that inter-chromosomal recombination between 2 types of CTX phages is possible when a host bacterial cell is infected by multiple CTX phages. Our study also provides molecular insights into population changes in V. cholerae in the absence of significant changes to the genome but by replacement of the CTX prophage that they harbor.