Characterization of high hydrostatic pressure-injured Bacillus subtilis cells*

High hydrostatic pressure (HHP) affects various cellular processes. Using a sporulation-deficient Bacillus subtilis strain, we characterized the properties of vegetative cells subjected to HHP. When stationary-phase cells were exposed to 250 MPa of HHP for 10 min at 25 °C, approximately 50% of cells were viable, although they exhibited a prolonged growth lag. The HHP-injured cells autolyzed in the presence of NaCl or KCl (at concentrations ≥100 mM). Superoxide dismutase slightly protected the viability of HHP-treated cells, whereas vegetative catalases had no effect. Thus, unlike HHP-injured Escherichia coli, oxidative stress only slightly affected vegetative B. subtilis subjected to HHP.     

Purification and characterization of fibrinolytic alkaline protease from <Emphasis Type="Italic">Fusarium</Emphasis> sp. BLB

Fusarium sp. BLB, which produces a strongly fibrinolytic enzyme, was isolated from plant leaf (Hibiscus). Fibrinolytic alkaline protease was purified from a culture filtrate of Fusarium sp. BLB by precipitation with (NH₄)₂SO₄ and column chromatography with CM-Toyopearl 650M and Superdex 75. The purified enzyme was homogeneous on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight was 27,000 by SDS-PAGE. Maximum activity of protease was observed at pH 9.5 and 50°C. Purified protease was active between pH 2.5 and 11.5 and was found to be stable up to 50°C. The enzyme derived from Fusarium sp. BLB is useful for thrombolytic therapy because this enzyme showed pH resistance. The activity was inhibited by diisopropylfluorophosphate and phenylmethylsulfonyl fluoride. The N-terminal amino acid sequence of the enzyme showed a similarity to those of proteases from Fusarium sp., Streptomyces griseus, Bos taurus bovine, Katsuwo pelamis digestive tract, and Lumbricus rubellus.     

Further studies on hepatitis C virus NS5B RNA-dependent RNA polymerase inhibitors toward improved replicon cell activities: benzimidazole and structurally related compounds bearing the 2-morpholinophenyl moiety

Following the discovery of JTK-109 (1) as a potent inhibitor of hepatitis C virus NS5B RNA-dependent RNA polymerase, [(a) Hirashima, S.; Suzuki, T.; Ishida, T.; Noji, S.; Yata, S.; Ando, I.; Komatsu, M.; Ikeda, S.; Hashimoto, H. J. Med. Chem.2006, 49, 4721. (b) Hashimoto, H.; Mizutani, K.; Yoshida, A. Int. Patent Appl. WO 01/47883, 2001.] further studies toward the improvement of the cellular potency have been performed. A greater than 40-fold improvement was achieved through replacing the biphenyl moiety with a 2-morpholinophenyl group and the benzimidazole ring with the tetracyclic scaffold to afford compound 7 with an excellent replicon potency (EC(50)=7.6 nM).     

Molecular and cellular mechanisms of syndecans in tissue injury and inflammation

The syndecan family of heparan sulfate proteoglycans is expressed on the surface of all adherent cells. Syndecans interact with a wide variety of molecules, including growth factors, cytokines, proteinases, adhesion receptors and extracellular matrix components, through their heparan sulfate chains. Recent studies indicate that these interactions not only regulate key events in development and homeostasis, but also key mechanisms of the host inflammatory response. This review will focus on the molecular and cellular aspects of how syndecans modulate tissue injury and inflammation, and how syndecans affect the outcome of inflammatory diseases in vivo.     

Glucosylceramide Contained in Koji Mold-Cultured Cereal Confers Membrane and Flavor Modification and Stress Tolerance to Saccharomyces cerevisiae during Coculture Fermentation

In nature, different microorganisms create communities through their physiochemical and metabolic interactions. Many fermenting microbes, such as yeasts, lactic acid bacteria, and acetic acid bacteria, secrete acidic substances and grow faster at acidic pH values. However, on the surface of cereals, the pH is neutral to alkaline. Therefore, in order to grow on cereals, microbes must adapt to the alkaline environment at the initial stage of colonization; such adaptations are also crucial for industrial fermentation. Here, we show that the yeast Saccharomyces cerevisiae, which is incapable of synthesizing glucosylceramide (GlcCer), adapted to alkaline conditions after exposure to GlcCer from koji cereal cultured with Aspergillus kawachii. We also show that various species of GlcCer derived from different plants and fungi similarly conferred alkali tolerance to yeast. Although exogenous ceramide also enhanced the alkali tolerance of yeast, no discernible degradation of GlcCer to ceramide was observed in the yeast culture, suggesting that exogenous GlcCer itself exerted the activity. Exogenous GlcCer also increased ethanol tolerance and modified the flavor profile of the yeast cells by altering the membrane properties. These results indicate that GlcCer from A. kawachii modifies the physiology of the yeast S. cerevisiae and demonstrate a new mechanism for cooperation between microbes in food fermentation.     

Effects of struvite formation and nitratation promotion on nitrogenous emissions such as NH3, N2O and NO during swine manure composting

To reduce nitrogenous emissions from composting, two different countermeasures were applied simultaneously in swine manure composting. One was forming struvite by adding Mg and P at the start of composting, and the other was to promote nitratation (nitrite being oxidized nitrate) by adding nitrite-oxidizing bacteria after the thermophilic phase of composting. In the laboratory- and mid-scale composting experiments, 25-43% of NH3, 52-80% of N2O and 96-99% of NO emissions were reduced. From the nitrogen balance, it was revealed that the struvite formation reduced not only NH3, but also other nitrogenous emissions except N2O. The amount of total nitrogen losses was reduced by 60% by the two combined countermeasures, against 51% by the struvite formation alone. However, the nitratation promotion dissolved struvite crystals due to the pH decline, diminishing the effect of struvite as a slow-release fertilizer.     

eNOS and Hsp90 interaction directly correlates with cord formation in human lymphatic endothelial cells

Endothelial nitric oxide synthase (eNOS) and heat shock protein 90 (Hsp90) have been reported to contribute to angiogenesis and lymphangiogenesis. However, the functions of these proteins during lymphangiogenesis are unclear. In the present study, we first observed the cord formation pattern of human dermal microvascular lymphatic endothelial cells (HMVEC-dLy) on Matrigel over 2 to 8?h. The length of cord formation increased, peaked at 4?h, and then started to decline after 6 to 8?h of incubation. siRNA-targeted NOS3 significantly reduced the cord formation ability of HMVEC-dLy cells by 27% relative to control. This result confirmed the importance of eNOS in cord formation by human lymphatic endothelial cells. In addition, immunoprecipitation and Western blotting indicated that the interaction between eNOS and Hsp90 was maximal at 4?h, and then the proteins dissociated. This interaction correlated with the observation of cord formation of human lymphatic endothelial cells on Matrigel. Moreover, we found that the eNOS level decreased as the eNOS and Hsp90 complex disassociated during the late stage of cord formation. An Hsp90 inhibitor, 17-DMAG, was able to inhibit the eNOS and Hsp90 interaction, decrease the level of eNOS, and significantly inhibit cord formation to 38% of the level observed in the control. For the first time, we report that the interaction between eNOS and Hsp90 plays an important role in determining eNOS levels and in regulating cord formation of human lymphatic endothelial cells in vitro.     

Antimalarial activity of endoperoxide compound 6-(1,2,6,7-tetraoxaspiro[7.11]nonadec-4-yl)hexan-1-ol

Plasmodium falciparum, the major causative parasite for the disease, has acquired resistance to most of the antimalarial drugs used today, presenting an immediate need for new antimalarial drugs. Here, we report the in vitro and in vivo antimalarial activities of 6-(1,2,6,7-tetraoxaspiro[7.11]nonadec-4-yl)hexan-1-ol (N-251) against P. falciparum and Plasmodium berghei parasites. The N-251 showed high antimalarial potencies both in the in vitro and the in vivo tests (EC₅₀ 2.3 × 10⁻⁸ M; ED₅₀ 15 mg/kg (per oral)). The potencies were similar to that of artemisinin in vitro and greater than artemisinin's activity in vivo (p.o.). In addition, N-251 has little toxicity: a single oral administration at 2000 mg/kg to a rat gave no health problems to it. Administration of N-251 to mice bearing 1% of parasitemia (per oral 68 mg/kg, 3 times a day for 3 consecutive days) resulted in a dramatic decrease in the parasitemia: all the 5 mice given N-251 were cured without any recurrence, with no diarrhea or weight loss occurring in the 60 days of experiment. N-251 deserves more extensive clinical evaluation, desirably including future trials in the human.     

Secernin-1 as a novel prognostic biomarker candidate of synovial sarcoma revealed by proteomics

We aimed to develop prognostic biomarkers for synovial sarcoma employing a proteomic approach. We examined the proteomic profile of synovial sarcoma using two-dimensional difference gel electrophoresis (2D-DIGE). We identified 20 protein spots whose intensity was statistically different (p<0.01) between a group of eight patients who were alive and continuously disease-free for over five years and a group of five patients who died of the disease within two years post diagnosis. Mass spectrometric protein identification demonstrated that these 20 spots corresponded to 17 distinct gene products. Three of the 20 spots corresponded to secernin-1 and had higher intensity in the good prognosis group. The prognostic performance of secernin-1 was further examined immunohistochemically in 45 synovial sarcoma cases. The 5-year survival rate was 77.6% and 21.8% for patients with secernin-1 positive and negative primary tumors respectively (p=0.0015). The metastasis-free survival was significantly higher in the patient group with high secernin-1 expression compared to that with low expression (p=0.0012). Uni- and multivariate analyses revealed that secernin-1 expression was a powerful prognostic factor compared to other clinico-pathological parameters examined. These results indicate that secernin-1 may be used as a biomarker to predict the overall and metastasis-free survival in synovial sarcoma patients.