A novel type of immunity protein, NukH, for the lantibiotic nukacin ISK-1 produced by Staphylococcus warneri ISK-1

Staphylococcus warneri ISK-1 produces a lantibiotic, nukacin ISK-1. The nukacin ISK-1 gene cluster consists of at least six genes, nukA, -M, -T, -F, -E, and -G, and two open reading frames, ORF1 and ORF7 (designated nukH). Sequence comparisons suggested that NukF, -E, -G, and -H contribute to immunity to nukacin ISK-1. We investigated the immunity levels of recombinant Lactococcus lactis expressing nukFEG and nukH against nukacin ISK-1. The co-expression of nukFEG and nukH resulted in a high degree of immunity. The expression of either nukFEG or nukH conferred partial immunity against nukacin ISK-1. These results suggest that NukH contributes cooperatively to self-protection with NukFEG. The nukacin ISK-1 immunity system might function against another lantibiotic, lacticin 481. Western blot analysis showed that NukH expressed in Staphylococcus carnosus was localized in the membrane. Peptide release/bind assays indicated that the recombinant L. lactis expressing nukH interacted with nukacin ISK-1 and lacticin 481 but not with nisin A. These findings suggest that NukH contributes cooperatively to host immunity as a novel type of lantibiotic-binding immunity protein with NukFEG.     

Development of Microsatellite Markers for Japanese Scallop (Mizuhopecten yessoensis) and Their Application to a Population Genetic Study

Abstract The Japanese scallop (Mizuhopecten yessoensis) is one of the main fishery products in Japan, but with the expansion of culture operations of the Japanese scallop, various problems have been encountered including high mortality, poor growth, poor seed production, and so on. Moreover, there is concern that many years of cultivation may have affected the genetic structure of the scallop population. To approach these problems and concerns, we developed microsatellite markers as a molecular tool for population genetic studies. By using 4 microsatellite markers as well as a mitochondrial marker, we investigated the genetic structure of samples from the islands of Hokkaido (14 populations) and Honshu (Tohoku, 3 populations) in Japan, and south Primorye (4 populations) in Russia. All the populations sampled had high genetic diversity (average expected heterozygosity, 0.7011 to 0.7622; haplotype diversity, 0.6090 to 0.8848), and almost all showed a tendency of homozygote excess, which was significant in 2 populations. Hierarchical analysis of molecular variance tests based on the microsatellite and mitochondrial markers indicated that the 3 geographic regions were genetically divergent from one another, with little evidence of divergence within regions. Homogeneity in allele frequency distributions between natural and cultured scallops and allele frequency stability over a period of 2 decades indicated that the culturing operations have probably not had a substantial effect on the genetic structure of the populations.     

Exercise-induced muscle damage impairs insulin signaling pathway associated with IRS-1 oxidative modification

Strenuous exercise induces delayed-onset muscle damage including oxidative damage of cellular components. Oxidative stress to muscle cells impairs glucose uptake via disturbance of insulin signaling pathway. We investigated glucose uptake and insulin signaling in relation to oxidative protein modification in muscle after acute strenuous exercise. ICR mice were divided into sedentary and exercise groups. Mice in the exercise group performed downhill running exercise at 30 m/min for 30 min. At 24 hr after exercise, metabolic performance and insulin-signaling proteins in muscle tissues were examined. In whole body indirect calorimetry, carbohydrate utilization was decreased in the exercised mice along with reduction of the respiratory exchange ratio compared to the rested control mice. Insulin-stimulated uptake of 2-deoxy-[(3)H]glucose in damaged muscle was decreased after acute exercise. Tyrosine phosphorylation of insulin receptor substrate (IRS)-1 and phosphatidyl-3-kinase/Akt signaling were impaired by exercise, leading to inhibition of the membrane translocation of glucose transporter 4. We also found that acute exercise caused 4-hydroxy-nonenal modification of IRS-1 along with elevation of oxidative stress in muscle tissue. Impairment of insulin-induced glucose uptake into damaged muscle after strenuous exercise would be related to disturbance of insulin signal transduction by oxidative modification of IRS-1.     

Haplotype-based case-control study of CYP4A11 gene and myocardial infarction

CYP4A11, which is a member of the cytochrome P450 family, acts mainly as an enzyme that converts arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a metabolite involved in the maintenance of cardiovascular health. Recently, it was reported that many subfamilies of CYP genes have an association with myocardial infarction (MI). The aim of the present study was to assess the association between the human CYP4A11 gene and MI, using a haplotype-based case-control study with a separate analysis of the gender groups. A total of 239 MI patients and 285 controls were genotyped for 3 single-nucleotide polymorphisms (SNPs) of the human CYP4A11 gene (rs2269231, rs1126742, rs9333025). The data obtained via haplotype-based case-control studies were assessed for 3 separate groups: total subjects, men, and women. For the total, men and women groups, the distribution of the genotypes and alleles of the 3 SNPs did not show any significant difference between the MI patients and the control subjects. For the total and the men groups, the overall distribution of the haplotypes constructed with the 3 SNPs significantly differed between the MI patients and control subjects (P < 0.001). Also, for the total and for the men, the frequency of the T-T-A haplotype constructed with the 3 SNPs was significantly lower for the MI patients than for the control subjects (both P 相似文献   

Radiocesium distribution in the tissues of Japanese black beef heifers fed fallout-contaminated roughage due to the fukushima daiichi nuclear power station accident

This study examined the accumulation and tissue distribution of radioactive cesium nuclides in Japanese Black beef heifers raised on roughage contaminated with radioactive fallout due to the accident at the Fukushima Daiichi Nuclear Power Station on March 2011. Radiocesium feeding increased both (134)Cs and (137)Cs levels in all tissues tested. The kidney had the highest level and subcutaneous adipose had the lowest of radioactive cesium in the tissues. Different radioactive cesium levels were not found among parts of the muscles. These results indicate that radiocesium accumulated highly in the kidney and homogenously in the skeletal muscles in the heifers.     

Six new chalcones from Angelica keiskei inducing adiponectin production in 3T3-L1 adipocytes

Angelica keiskei (Ashitaba in Japanese), a traditional herb in Japan, contains abundant prenylated chalcones. It has been reported that the chalcones from A. keiskei showed such bioactivities as anti-bacterial, anti-cancer and anti-diabetic effects. Xanthoangelol, 4-hydroxyderricin and six new chalcones were isolated in this study from an ethanol extract of A. keiskei by octadecyl silyl (ODS) and silica gel chromatography, and identified by 1D- and 2D-nuclear magnetic resonance (NMR) and high-resolution mass spectrometric analyses. The chalcones from A. keiskei markedly increased the expression of the adiponectin gene and the production of adiponectin in 3T3-L1 adipocytes. These results suggest that the chalcones from A. keiskei might be useful for preventing the metabolic syndrome.     

Structure-activity relationship studies of S1P agonists with a dihydronaphthalene scaffold

Structure-activity relationship (SAR) of sphingosine-1-phosphate receptor agonists with a dihydronaphthalene scaffold was investigated. Compound 1 was modified to improve S1P(1) agonistic activity and in vivo peripheral lymphocyte lowering (PLL) activity without impairing selectivity over S1P(3) agonistic activity. A detailed SAR study of the terminal lipophilic part revealed that the introduction of substituents on the propylene linker and the terminal benzene ring influences in vitro and PLL activities. Compound 6n bearing a (S)-methyl group at the 2-position on the propylene linker and chlorine at the para-position on the terminal benzene ring showed potent hS1P(1) agonistic activity with excellent selectivity over hS1P(3) and in vivo PLL activity in mice.     

Phosphatidylinositol 3-kinase/Akt signaling mediates interleukin-32alpha induction in human pancreatic periacinar myofibroblasts

Interleukin (IL)-32 is a recently described proinflammatory cytokine, characterized by the induction of nuclear factor (NF)-kappaB activation. We studied IL-32alpha expression in human pancreatic periacinar myofibroblasts, which play important roles in the regulation of extracellular matrix metabolism and inflammatory responses in the pancreas. IL-32alpha protein expression was evaluated by Western blot analyses, and IL-32alpha mRNA expression was analyzed by Northern blot and real-time PCR analyses. IL-32alpha mRNA was weakly expressed without a stimulus, and its expression was markedly enhanced by IL-1beta, IFN-gamma, and TNF-alpha. IL-1beta, IFN-gamma, and TNF-alpha enhanced intracellular accumulation of IL-32alpha protein, but IL-32alpha was not detected in supernatants. Each cytokine dose and time dependently induced IL-32alpha mRNA expression. An inhibitor of phosphatidylinositol 3-kinase (LY294002) significantly suppressed IL-1beta-, IFN-gamma-, and TNF-alpha-induced IL-32alpha mRNA expression, although MAPK inhibitors had no effect. Akt activation in response to these cytokines was confirmed by Western blot. Furthermore, LY294002 suppressed both IL-1beta- and TNF-alpha-induced NF-kappaB activation and IL-1beta-, TNF-alpha-, and IFN-gamma-induced activated protein-1 (AP-1) activation. Blockade of NF-kappaB and AP-1 activation by an adenovirus expressing a stable mutant form of IkappaBalpha and a dominant negative mutant of c-Jun markedly suppressed IL-1beta-, IFN-gamma-, and/or TNF-alpha-induced IL-32alpha mRNA expression. Human pancreatic periacinar myofibroblasts expressed IL-32alpha in response to IL-1beta, TNF-alpha, and IFN-gamma. IL-32alpha mRNA expression is dependent on interactions between the phosphatidylinositol 3-kinase/Akt-pathway and the NF-kappaB/AP-1 system.     

Microchamber arrays for the identification of individual cells exposed to an X-ray microbeam

To identify individual cells exposed to a X-ray microbeam in a cell population, we developed a biocompatible microchamber-array chip using UV lithography of photopolymer SU-8. The center-to-center distance between microchambers is 50 μm including a wall of 15 μm height. Using the microchamber-array chip, we performed tracking of individual exposed cells. Sample cells loaded in a microchamber array were selectively irradiated with the X-ray microbeam under microscopic observation. All the irradiated cells were indexed by the array arrangement of the microchambers. For about 24 h of post-irradiation incubation, the irradiated cells were identified successfully by time-lapse observation. In addition, the induction of radiation effects was observed in identified cells using immunofluorescence.