The life cycle of Hymenoscyphus fraxineus on Manchurian ash,Fraxinus mandshurica,in Japan

Hymenoscyphus fraxineus causes a lethal disease known as “ash dieback” in the common ash, Fraxinus excelsior, in Europe. It is hypothesized that the fungus originated from East Asia. This fungus is found on the leaf litter of the Manchurian ash, Fraxinus mandshurica, in Japan and is reported to produce apothecia on pseudosclerotial plates formed mainly on decomposing rachises. However, dieback disease has not been reported in Japan, and little is known about the life cycle of H. fraxineus. This study was conducted to explore the behavior and life cycle of this fungus. It was revealed that, after infection by ascospores, H. fraxineus endophytically inhabits the living leaves of F. mandshurica. On fallen leaves, the fungus behaves saprophytically, producing apothecia on pseudosclerotial plates formed mainly on the decomposing rachises. Analysis by real-time quantitative polymerase chain reaction (qPCR) revealed that the amount of H. fraxineus DNA sharply increased in rachises, while such sharp increase of DNA was not found in leaflets.     

The inhibitory effects of mushroom extracts on sucrose-dependent oral biofilm formation

Mushrooms contain large quantities of α-glucans. Shiitake (Lentinula edodes), Japan’s most popular edible mushroom, has been reported to contain about 6% (weight/dried weight) of α-(1,3)-glucan. This glucan is one of the major components of oral biofilm formed by the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. We found that extracts from shiitake and other edible mushrooms could reduce preformed biofilms of S. mutans and S. sobrinus in the presence of dextranase. We also investigated the α-glucanase activities of shiitake mushroom extracts and their effects on biofilm formation. The extracts possessed α-glucanase activity and degraded water-insoluble glucans from mutans streptococci. The extracts strongly inhibited the sucrose-dependent formation of biofilms by S. mutans and S. sobrinus in the presence of dextranase. Our results suggest that some components of mushrooms, including α-glucanases, might inhibit the sucrose-induced formation of oral biofilms.     

Induction of cell size vesicles from human lymphoma cell lines and their application to drug carriers

Sodium butyrate (NaB) induced the membrane enclosed cell size vesicles from several IgM producing cell lines. We considered the application of the cell-derived vesicles (CDVs) to drug delivery system (DDS) using the lung cancer specific IgM producing AE6 cell line. Microscopic observation showed that the DiI fluorescence labeled AE6 vesicles were incorporated into the lung cancer cell line A549. The anticancer drug, actinomycin D (actD), contained in AE6 and Ramos vesicles decreased the A549 cell viability to 46 and 62% of control without actD, respectively. The cytotoxic effect in AE6 vesicles was superior to that in the Ramos vesicles that have the lung cancer non-specific IgM on their surfaces. However, the result of the Ramos vesicles suggests that the surface molecules other than IgM may interact with the A549 cells. In our method for vesicle production, more specific and abundant antibodies mounted vesicles can be generated by transfection of their genes into cells followed by NaB treatment. These suggest that the CDVs may be useful for the development of a drug carrier for DDS.     

Novel selective anti-androgens with a diphenylpentane skeleton

We have proposed a multi-template approach for drug development, focusing on similar fold structures of proteins, and have effectively generated lead compounds for several drug targets. Modification of these polypharmacological lead compounds is then needed to generate target-selective compounds. In the work presented here, we aimed at separation of the anti-androgen activity and vitamin D activity of previously identified diphenylpentane lead compounds. Based on the determined X-ray crystal structures of androgen receptor and vitamin D receptor, bulky substituents were introduced at the t-butyl group in the lead compounds 2 and 3. As a result of this structural development, we obtained 16c, which exhibits more potent anti-androgen activity (IC(50): 0.13 μM) than clinically used anti-androgen bicalutamide (IC(50): 0.67 μM) with 30-fold selectivity over vitamin D activity. This result indicates that lead compounds obtained via the multi-template approach can indeed be structurally modified to generate target-selective compounds.     

Assessment of phytoavailability of Sr in an Andosol by addition of stable isotope

Time-dependent changes of phytoavailability of Sr after adding it to the soil were studied for better prediction of radioactive Sr behavior in soil–plant systems. Strontium-86 enriched stable isotope was added to a soil sample collected from a field of humus-rich Andosol. Plant uptake and extractability of Sr in the soil were assessed at given times after the addition during a 12-month period including repeated drying-rewetting. Proportion of the added Sr extracted by 1 M ammonium acetate solution from the soil was 45–58% throughout the period, which corresponded to that of long-time aged ⁹⁰Sr in the soil. Pot cultivations of orchardgrass (Dactylis glomerata) and red clover (Trifolium pratense) were carried out starting with uncropped soil for four weeks five times during the experiment. Clear time-dependent changes were not observed in uptake of the added Sr by the plants. Aging is unlikely to decrease Sr availability over time. The labile form of Sr determined with the isotopic dilution method was approximately 15% of total soil Sr, and more than the percentage of the extractable Sr in the soil. The results suggest that a part of the non-extractable forms of Sr in the soil would be available to the plant.     

A new class of carriers that transport selective cargo from the trans Golgi network to the cell surface

We have isolated a membrane fraction enriched in a class of transport carriers that form at the trans Golgi network (TGN) and are destined for the cell surface in HeLa cells. Protein kinase D (PKD) is required for the biogenesis of these carriers that contain myosin II, Rab6a, Rab8a, and synaptotagmin II, as well as a number of secretory and plasma membrane‐specific cargoes. Our findings reveal a requirement for myosin II in the migration of these transport carriers but not in their biogenesis per se. Based on the cargo secreted by these carriers we have named them CARTS for CAR riers of the T GN to the cell S urface. Surprisingly, CARTS are distinct from the carriers that transport vesicular stomatitis virus (VSV)‐G protein and collagen I from the TGN to the cell surface. Altogether, the identification of CARTS provides a valuable means to understand TGN to cell surface traffic.     

Augmentation of fatality of influenza in mice by inhibition of phagocytosis

Influenza virus-infected cells undergo apoptosis and become susceptible to phagocytosis by macrophages, and this leads to the inhibition of virus propagation in vitro. To assess if this were also true in vivo, mice infected with influenza A/WSN (H1N1) virus were administered with phagocytosis inhibitors and examined for the progress of influenza. Administration of the inhibitors caused a decrease in the level of phagocytosis observed with bronchoalveolar lavage cells. We found that both the lethality in mice and the extent of inflammation in the lung were augmented in those mice. These results suggest that phagocytosis of virus-infected cells helps suppress the progress of influenza in mice.     

Formation of lipid droplets induced by 2,3-dihydrogeranylgeranoic acid distinct from geranylgeranoic acid

Geranylgeranoic acid (GGA) and 2,3-dihydrogeranylgeranoic acid (2,3-diGGA) are geranylgeraniol-derived metabolites (Kodaira et al. (2002) J Biochem 132: 327-334). In the present study, we examined the effects of these acids on HL-60 cells. The cells were differentiated into neutrophils by GGA stimulation like retinoic acid stimulation. In the case of cells stimulated with 2,3-diGGA, neutrophils were not detected, but the formation of lipid droplets was induced. On the other hand, when the cells were cultured in the presence of 0.1% FBS instead of 10% FBS, apoptotic cells were induced not only by GGA stimulation but also with 2,3-diGGA. In the latter case, when the cells were cultured in the co-presence of a caspase-3 inhibitor (Ac-DMQD-CHO), the lipid droplets formation was observed in the cells. These results suggest that GGA and 2,3-diGGA are extremely different from each other with respect to their effects on HL-60 cells.