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Latest Paper:
Protein J. 2012 May 8;:
22565346
Keita Miyata,
Yoshimasa Sagane,
Ken Inui,
Shin-Ichiro Miyashita,
Tomonori Suzuki,
Keiji Oguma,
Tohru Ohyama,
Koichi Niwa,
Toshihiro Watanabe
Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan.
The large-sized botulinum toxin complex (L-TC) is composed of botulinum neurotoxin (BoNT) and nontoxic proteins, e.g. nontoxic nonhemagglutinin (NTNHA) and three types of hemagglutinins (HAs; HA-33, HA-17 and HA-70). The nontoxic proteins play a critical role in L-TC oral toxicity by protecting the BoNT in the digestive tract, and facilitating absorption of the L-TC across the intestinal wall. Under alkaline conditions, the L-TC separates into BoNT and the nontoxic protein complex (NC). In this study, we established a two-step procedure to yield highly pure NC from the L-TC produced by Clostridium botulinum serotype D strain 4947 in which the NC was isolated from the L-TC by gel filtration under alkaline conditions followed by immunoprecipitation with an anti-BoNT antibody to remove contaminating BoNT from the NC fraction. Western blotting and electrophoretic analysis showed that the highly purified NC fraction had only very slight or no BoNT contamination. In addition, the purified NC fraction showed no intraperitoneal (ip) toxicity to mice at a dose of 38 ng per animal whereas the L-TC exhibited an ip median lethal dose of 0.38 ng per mouse. The highly purified NC displayed the same hemagglutination titer as the L-TC. The NC, as well as the L-TC, demonstrated cell binding and monolayer transport in the rat intestinal epithelial cell line IEC-6. Consequently, the highly purified NC can function as a "delivery vehicle" even without the BoNT.
Thromb Res. 2012 Mar 27;:
22459906
Department of Emergency and Disaster Medicine, Juntendo University, Tokyo, Japan.
INTRODUCTION: The metabolic syndrome is considered to be a risk factor for the venous thromboembolism (VTE) as well as arterial thrombosis. Although obesity, hyperglycemia and dyslipidemia are considered to be important triggering factors, it is difficult to evaluate the relationship between VTE and the metabolic syndrome in a clinical study. Furthermore the mechanism of venous thrombosis initiation still remains elusive. MATERIALS AND METHODS: 20min clamp of superior mesenteric vein was applied to 7w, 16w-old KK-A(y) mouse and 16w-old B6J mouse (n=6 in each group), after de-clamp, the view of the mesenteric vein and intestinal submucosal venule were observed by the intravital microscopy. RESULTS: Massive thrombi formed in the mesenteric vein in 16w-old KK-A(y) mice, moderate thrombi formation was observed in 7w-old KK-A(y) mice, while very few thrombi were observed in B6J mice. The first event in submucosal venule after de-clamp was the adhesion of leukocytes to the endothelium. Subsequently, leukocytes assembled and platelets covered the leukocyte cluster. These leukocyte-platelet aggregates move from the venule to the vein and finally formed a venous thrombus. CONCLUSION: Metabolic syndrome is a risk factor for venous thrombosis. Intravital microscopic examination revealed leukocyte and platelet recruitment to the venule in the early stages of venous thrombosis formation.
Ken Inui,
Yoshimasa Sagane,
Keita Miyata,
Shin-Ichiro Miyashita,
Tomonori Suzuki,
Yasuyuki Shikamori,
Tohru Ohyama,
Koichi Niwa,
Toshihiro Watanabe
Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493, Japan; Japan Society for the Promotion of Science, Japan.
Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X(35)-D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.
PLoS One. 2012 ;7 (2):e31465
22359594
Kenshiro Tsuda,
Keiichi Yamanaka,
Hiroshi Kitagawa,
Tomoko Akeda,
Masanao Naka,
Kaori Niwa,
Takehisa Nakanishi,
Masato Kakeda,
Esteban C Gabazza,
Hitoshi Mizutani
Department of Dermatology, Mie University, Graduate School of Medicine, Tsu, Mie, Japan.
T cells have been classified as belonging to the Th1 or Th2 subsets according to the production of defining cytokines such as IFN-γ and IL-4. The discovery of the Th17 lineage and regulatory T cells shifted the simple concept of the Th1/Th2 balance into a 4-way mechanistic pathway of local and systemic immunological activity. Clinically, the blockage of cytokine signals or non-specific suppression of cytokine predominance by immunosuppressants is the first-line treatment for inflammatory T cell-mediated disorders. Cyclosporine A (CsA) and Tacrolimus (Tac) are commonly used immunosuppressants for the treatment of autoimmune disease, psoriasis, and atopic disorders. Many studies have shown that these compounds suppress the activation of the calcium-dependent phosphatase calcineurin, thereby inhibiting T-cell activation. Although CsA and Tac are frequently utilized, their pharmacological mechanisms have not yet been fully elucidated.In the present study, we focused on the effects of CsA and Tac on cytokine secretion from purified human memory CD4(+)T cells and the differentiation of naïve T cells into cytokine-producing memory T cells. CsA or Tac significantly inhibited IFN-γ, IL-4, and IL-17 production from memory T cells. These compounds also inhibited T cell differentiation into the Th1, Th2, and Th17 subsets, even when used at a low concentration. This study provided critical information regarding the clinical efficacies of CsA and Tac as immunosuppressants.
Takayuki Nagae,
Takashi Kawamura,
Leonard M G Chavas,
Ken Niwa,
Masashi Hasegawa,
Chiaki Kato,
Nobuhisa Watanabe
Department of Biotechnology, Graduate School of Engineering, Nagoya University, Japan.
Hydrostatic pressure induces structural changes in proteins, including denaturation, the mechanism of which has been attributed to water penetration into the protein interior. In this study, structures of 3-isopropylmalate dehydrogenase (IPMDH) from Shewanella oneidensis MR-1 were determined at about 2 Å resolution under pressures ranging from 0.1 to 650 MPa using a diamond anvil cell (DAC). Although most of the protein cavities are monotonically compressed as the pressure increases, the volume of one particular cavity at the dimer interface increases at pressures over 340 MPa. In parallel with this volume increase, water penetration into the cavity could be observed at pressures over 410 MPa. In addition, the generation of a new cleft on the molecular surface accompanied by water penetration could also be observed at pressures over 580 MPa. These water-penetration phenomena are considered to be initial steps in the pressure-denaturation process of IPMDH.
Keita Miyata,
Ken Inui,
Shin-Ichiro Miyashita,
Yoshimasa Sagane,
Kimiko Hasegawa,
Takashi Matsumoto,
Akihito Yamano,
Koichi Niwa,
Toshihiro Watanabe,
Tohru Ohyama
Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri, Hokkaido, Japan.
Clostridium botulinum produces botulinum neurotoxin (BoNT) as a large toxin complex assembled with nontoxic nonhaemagglutinin (NTNHA) and/or haemagglutinin components. Complex formation with NTNHA is considered to be critical in eliciting food poisoning because the complex shields the BoNT from the harsh conditions in the digestive tract. In the present study, NTNHA was expressed in Escherichia coli and crystallized. Diffraction data were collected to 3.9 Å resolution. The crystal belonged to the trigonal space group P321 or P3(1)21/P3(2)21, with unit-cell parameters a = b = 147.85, c = 229.74 Å. The structure of NTNHA will provide insight into the assembly mechanism that produces the unique BoNT-NTNHA complex.
Cardiovascular Center, St. Luke's International Hospital, 9-1, Akashi-cho, Chuo-ku, Tokyo, Japan. atmizu@gmail.com
Deciding how to treat acute myocardial infarction (MI) with myocardial bridge is difficult because stent fracture and early restenosis are frequently reported. We present a 50-year-old female patient with acute MI and myocardial bridge. Optical coherence tomography (OCT) and fractional flow reserve were used to reach a decision on treatment.
Int J Cardiol. 2012 Jan 6;:
22227251
Hisanori Sakazaki,
Koichiro Niwa,
Makoto Nakazawa,
Tsutomu Saji,
Toshio Nakanishi,
Motoki Takamuro,
Michihiko Ueno,
Hitoshi Kato,
Shinichi Takatsuki,
Masaki Matsushima,
Namiko Kojima,
Fukiko Ichida,
Shigetoyo Kogaki,
Sachiko Kido,
Yoshio Arakaki,
Kenji Waki,
Teiji Akagi,
Kunitaka Joo,
Jun Muneuchi,
Kenji Suda,
Heung Jae Lee,
Haruo Shintaku
Department of Pediatric Cardiology, Hyogo Prefectural Amagasaki Hospital, Japan.
BACKGROUND: There are few articles on mortality and morbidity of adult patients with Eisenmenger's syndrome (ES) in the current era when disease targeting therapy (DTT) has been available. METHODS AND RESULTS: 198 patients (a median age 35years, 64% female) with ES who visited the 16 participating institutes in Japan and Korea from 1998 to 2009 were enrolled. Clinical data during adulthood were collected from each institutional chart and analyzed centrally. During a median follow-up of 8years, 30 patients died including 14 sudden deaths. 89 patients took oral medication of DTT and clinical improvement was observed in 54 of them. However, survival rate in patients taking DTT was not different from those without (87% vs 84%, p=0.55). When the clinical data in between first and last clinic visits were compared in 85 patients, the patients with NYHA ≧ III increased from 24% to 48%(p<0.001), SpO(2) decreased from 89% to 85%(p=0.008) and hematocrit increased from 51.4% to 52.9%(p=0.04). Non-survivors had poorer NYHA function class, lower body weight (BW), lower body mass index (BMI), and higher serum level of Cr at the first visits than survivors. CONCLUSIONS: Long term survival and clinical status of adult patients with ES remains unsatisfactory even in the current era of DTT. Poor NYHA functional class, low BW, low BMI and high serum level of Cr were related to mortality. DTT therapy improved clinical status in many patients with Eisenmenger's syndrome, but no significant impact on survival could be shown.
Anim Genet. 2012 Feb ;43 (1):98-103
22221031
T Shimogiri,
N Nishida,
M Kudo,
K Niwa,
M Nishibori,
K Kinoshita,
S Okamoto,
Y Maeda,
K Tokunaga,
H Yasue
Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan. Department of Human Genetics, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan. NGK Insulators, Ltd., Mizuho-ku, Nagoya 467-8530, Japan. Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima 739-8528, Japan. Avian Bioscience Research Center, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan. Genome Research Department, National Institute of Agrobiological Sciences, Tsukuba 305-0901, Japan.
Recently, single nucleotide polymorphisms (SNPs) have been used to identify genes or genomic regions responsible for economic traits, including genetic diseases in domestic animals, and to examine genetic diversity of populations. In this study, we genotyped 70 chicken autosomal SNPs using DigiTag2 assay to understand the genetic structure of the Japanese native chicken breeds Satsumadori and Ingie, and the relationship of these breeds with other established breeds, Rhode Island Red (RIR), commercial broiler and layer. Five breeds, each consisting of approximately 20 chickens, were subjected to the assay, revealing the following: Average expected heterozygosities of broiler, Satsumadori, RIR, layer and Ingie were 0.265, 0.254, 0.244, 0.179 and 0.176, respectively. Phylogenetic analysis using the concatenated 70 autosomal SNP genotypes distinguished all chickens and formed clusters of chickens belonging to the respective breeds. In addition, the 2-D scatter plot of the first two principal components was consistent with the phylogenic tree. Taken together with the pairwise F(st) distances, broiler and RIR were closely positioned near each other, while Ingie was positioned far from the other breeds. Structure analysis revealed that the probable number of genetic clusters (K) was six and four with maximum likelihood and ΔK values, respectively. The clustering with maximum likelihood revealed that, in addition to the clustering of the other five breeds, the Satsumadori was subdivided into two genetic clusters. The clustering with ΔK value indicated that the broiler and Rhode Island Red were assigned to the same genetic cluster.
Chem Commun (Camb). 2012 Jan 5;:
22218646
Hiroyuki Asanuma,
Takuya Osawa,
Hiromu Kashida,
Taiga Fujii,
Xingguo Liang,
Kosuke Niwa,
Yasuko Yoshida,
Naohiko Shimada,
Atsushi Maruyama
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan. asanuma@mol.nagoya-u.ac.jp.
In the presence of poly(l-lysine)-graft-dextran, an in-stem molecular beacon involving three perylene-anthraquinone pairs in the stem region had a signal/background ratio of as high as 570. Response speed was also remarkable; equilibrium was attained within 5 minutes after addition of substrate DNA at 20 °C.
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