Hydropiperoside,a novel coumaryl glycoside from the root of Polygonum hydropiper

From the methanol extract of the root of Polygonum hydropiper, a novel coumaryl glycoside hydropiperoside was isolated together with anthraquinone, ellagic acid 3,3′-di-O-methyl ether, gallic acid, two quercetin glycosides and an unidentified aromatic δ-lactone possessing antifertility activity. The structure of hydropiperoside was established as β-d-(1,3,6-tri-p-coumaryl)-fructofuranosyl-α-d-glucopyranoside by combination of extensive ¹H NMR and ¹³C NMR spectra, and the FD/MS spectrum.     

A Drosophila receptor-type tyrosine kinase (DFR1) acts as a fibroblast growth factor receptor in Xenopus embryos

Members of the fibroblast growth factor (FGF) family play important roles in various developmental processes in vertebrates. Since two genes closely related to the vertebrate FGF receptor (FGFR) genes DFR1 and DFR2/breathless have already been reported in Drosophila , the existence of a Drosophila FGF has been predicted. In the present study, we examined whether DFR1 is functionally interchangeable with a vertebrate FGFR in the Xenopus system. First, we found that the expression of DFR1 promoted Ca²⁺ efflux in response to human basic (b)FGF in Xenopus oocytes, whereas the coexpression of a dominant negative form of DFR1 (ΔDFR1) with a chick FGFR1/cek1 inhibited promotion of Ca²⁺ efflux induced by the expression of cek1 in the oocyte. Second, the expression of ΔDFR1 was observed to induce a defect in the posterior structure of the Xenopus embryo at stage 30, as observed with a dominant negative form of cek1 (Δcek1). Third, we found that the expression of ΔDFR1 inhibited the expression of FGF-regulated genes such as Xbra, Xnot , and Xshh in Xenopus embryos at stage 11, while the coexpression of DFR1 with ΔDFR1 could rescue the inhibited expression of FGF-regulated genes. These results indicate that DFR1 acts as an FGFR in Xenopus embryos and that an FGF is likely to exist in Drosophila .     

Analysis of germinal aging in Paramecium caudatum by micronuclear transplantation

The role of the micronucleus in the age-dependent increase in mortality after conjugation in Paramecium has been investigated using micronuclear transplantation. The clone of Paramecium caudatum used for this study had a lifespan of about 750 fissions. In this clone, the fission rate began to decrease about 450 fissions after conjugation. Mortality after selfing conjugation also began to appear at about 450 fissions and gradually increased with clonal age. Cells at about 650 fissions showed 10–70% survival after selfing conjugation but when their micronuclei were transplanted into amicronucleate cells of about 450 fissions, the progeny survival increased to 70–90%. When micronuclei from cells 700–750 fissions old were transplanted into amicronucleate cells of 100–150 fissions, however, increase in progeny survival was very rare. The results indicate that micronuclei in cells up to the age of 650 fissions can function normally if the cytoplasmic environment is young.     

Annexin A4 Is Involved in Proliferation,Chemo-Resistance and Migration and Invasion in Ovarian Clear Cell Adenocarcinoma Cells

Ovarian clear cell adenocarcinoma (CCC) is the second most common subtype of ovarian cancer after high-grade serous adenocarcinomas. CCC tends to develop resistance to the standard platinum-based chemotherapy, and has a poor prognosis when diagnosed in advanced stages. The ANXA4 gene, along with its product, a Ca⁺⁺-binding annexin A4 (ANXA4) protein, has been identified as the CCC signature gene. We reported two subtypes of ANXA4 with different isoelectric points (IEPs) that are upregulated in CCC cell lines. Although several in vitro investigations have shown ANXA4 to be involved in cancer cell proliferation, chemoresistance, and migration, these studies were generally based on its overexpression in cells other than CCC. To elucidate the function of the ANXA4 in CCC cells, we established CCC cell lines whose ANXA4 expressions are stably knocked down. Two parental cells were used: OVTOKO contains almost exclusively an acidic subtype of ANXA4, and OVISE contains predominantly a basic subtype but also a detectable acidic subtype. ANXA4 knockdown (KO) resulted in significant growth retardation and greater sensitivity to carboplatin in OVTOKO cells. ANXA4-KO caused significant loss of migration and invasion capability in OVISE cells, but this effect was not seen in OVTOKO cells. We failed to find the cause of the different IEPs of ANXA4, but confirmed that the two subtypes are found in clinical CCC samples in ratios that vary by patient. Further investigation to clarify the mechanism that produces the subtypes is needed to clarify the function of ANXA4 in CCC, and might allow stratification and improved treatment strategies for patients with CCC.     

HLA-DQB1*03 Confers Susceptibility to Chronic Hepatitis C in Japanese: A Genome-Wide Association Study

Hepatitis C virus (HCV) establishes a chronic infection in 70-80% of infected individuals. Many researchers have examined the effect of human leukocyte antigen (HLA) on viral persistence because of its critical role in the immune response against exposure to HCV, but almost all studies have proven to be inconclusive. To identify genetic risk factors for chronic HCV infection, we analyzed 458,207 single nucleotide polymorphisms (SNPs) in 481 chronic HCV patients and 2,963 controls in a Japanese cohort. Next, we performed a replication study with an independent panel of 4,358 cases and 1,114 controls. We further confirmed the association in 1,379 cases and 25,817 controls. In the GWAS phase, we found 17 SNPs that showed suggestive association (P < 1 × 10^-5). After the first replication study, we found one intronic SNP in the HLA-DQ locus associated with chronic HCV infection, and when we combined the two studies, the association reached the level of genome-wide significance. In the second replication study, we again confirmed the association (P _combined = 3.59 × 10⁻¹⁶, odds ratio [OR] = 0.79). Subsequent analysis revealed another SNP, rs1130380, with a stronger association (OR=0.72). This nucleotide substitution causes an amino acid substitution (R55P) in the HLA-DQB1 protein specific to the DQB1*03 allele, which is common worldwide. In addition, we confirmed an association with the previously reported IFNL3-IFNL4 locus and propose that the effect of DQB1*03 on HCV persistence might be affected by the IFNL4 polymorphism. Our findings suggest that a common amino acid substitution in HLA-DQB1 affects susceptibility to chronic infection with HCV in the Japanese population and may not be independent of the IFNL4 genotype.     

Impacts of invasive crayfish (Pacifastacus leniusculus) on endangered freshwater pearl mussels (Margaritifera laevis and M. togakushiensis) in Japan

The invasive alien crayfish Pacifastacus leniusculus is considered harmful to freshwater pearl mussels Margaritifera laevis and M. togakushiensis. It also often colonises mussel habitats in Japan. In order to test the negative effects of alien crayfish on mussels, we evaluated the predation impact of signal crayfish on freshwater pearl mussels in vitro. We tested the relationship between the survival/injury rates of mussels and crayfish predation with respect to different sizes of mussels (four classes based on shell length: 10, 30, 50 and 70 mm). Crayfish selectively fed on the flesh of the 10-mm size class mussels after breaking their shells. The shell margins of mussels in all size classes were injured by crayfish. Results also showed that crayfish particularly injured the 50-mm size class of mussels. This observation could be attributed to this mussel size being the most suitable shell size (29.56–37.73 mm in carapace length) that the crayfish can effectively hold. This study shows that the presence of invasive crayfish reduces freshwater pearl mussel populations by damaging the shell margins and/or killing the mussels. This negative impact of invasive crayfish not only decreases the mussel population but could also limit mussel recruitment, growth and reproduction.     

Purification and Properties of meso-α,∊-Diaminopimelate Decarboxylase from Bacillus sphaericus

Soybean 7S and 11S globulins were stored at relative humidities (RHs) of 11% and 96% at 50°C. The redispersibility of the proteins at RH 96% decreased in a short time. However, it did not decrease, when stored for 45 days at RH 11%. Gel filtration showed that the proteins polymerized during storage. The effects of urea, sodium dodecyl sulfate (SDS) and 2-mercaptoethanol (2-ME) on the redispersibilities of the proteins at RH 96% showed that the hydrogen, hydrophobic and disulfide bonds participate in the polymerization of 7S globulin, and that the disulfide bond is strongly related to the polymerization of 11S globulin. Redispersibility was restored with 2-ME in both the 7S and 11S globulins and some of the proteins in the supernatant redispersed with 2-ME were observed to be similar to the native ones with respect to the gel filtration, electrophoretic behavior and circular dichroism spectrum.     

Change in distribution of the vascular plant Sasa palmata in Sarobetsu Mire between 1977 and 2003

In recent decades, the extent of Sasa palmata-dominant communities has increased in Sarobetsu Mire in northern Hokkaido, Japan, replacing the original Sphagnum bog vegetation. However, this marked increase in distribution of Sasa in the mire has not been formally documented or investigated in detail. Using aerial photo-interpretation, the present study updated the distribution maps of Sasa communities, showing the changes that have occurred to these communities between 1977 and 2003. The results revealed that the extent of Sasa communities has increased by 15.8 % from 6.60 km² in 1977 to 7.64 km² in 2003. The most marked increase occurred on the ground associated with drainage channels, although the oldest channels were constructed more than half a century ago, suggesting that some responses to the drainage of peat bog ecosystems may take a considerable period of time before becoming particularly evident.     

Theoretical study on flow-dependent concentration polarization of low density lipoproteins at the luminal surface of a straight artery

It is suspected that physical and fluid mechanical factors play important roles in the localization of atherosclerotic lesions and intimal hyperplasia in man by affecting the transport of cholesterol in flowing blood to arterial walls. Hence, we have studied theoretically the effects of various physical and fluid mechanical factors such as wall shear rate, diffusivity of low density lipoproteins (LDL), and filtration velocity of water at the vessel wall on surface concentration of LDL at an arterial wall by means of a computer simulation of convective and diffusive transport of LDL in flowing blood to the wall of a straight artery under conditions of a steady flow. It was found that under normal physiologic conditions prevailing in the human arterial system, due to the presence of a filtration flow of water at the vessel wall, flow-dependent concentration polarization (accumulation or depletion) of LDL occurs at a blood/endothelium boundary. The surface concentration of LDL at an arterial wall takes higher values than that in the bulk flow in that vessel, and it is affected by three major factors, that is, wall shear rate, gamma w, filtration velocity of water at the vessel wall, Vw, and the distance from the entrance of the artery, L. It increases with increasing Vw and L, and decreasing gamma w hence the flow rate. Thus, under certain circumstances, the surface concentration of LDL could rise locally to a value which is several times higher than that in the bulk flow, or drop locally to a value even lower than a critical concentration for the maintenance of normal functions and survival of cells forming the vessel wall. These results suggest the possibility that all the vascular phenomena such as the localization of atherosclerotic lesions and intimal hyperplasia, formation of cerebral aneurysms, and adaptive changes of lumen diameter and wall structure of arteries and veins to certain changes in hemodynamic conditions in the circulation are governed by this flow-dependent concentration polarization of LDL which carry cholesterol.