Crystal structure of the hemolytic lectin CEL-III isolated from the marine invertebrate Cucumaria echinata : Implications of domain structure for its membrane pore-formation mechanism

CEL-III is a Ca^＋ -dependent and galactose-specific lectin purified from the sea cucumber, Cucumaria echinata, which exhibits hemolytic and hemagglutinating activities. Six molecules of CEL-III are assumed to oligomerize to form an ion-permeable pore in the cell membrane. We have determined the crystal structure of CEL-III by using single isomorphous replacement aided by anomalous scattering in lead at 1.7 Å resolution. CEL-III consists of three distinct domains as follows: the N-terminal two carbohydrate-binding domains (1 and 2), which adopt β-trefoil folds such as the B-chain of ricin and are members of the (QXW)_3 motif family; and domain 3, which is a novel fold composed of two α-helices and one β-sandwich. CEL-III is the first Ca^ -dependent lectin structure with two β-trefoil folds. Despite sharing the structure of the B-chain of ricin, CEL-III binds five Ca^ ions at five of the six subdomains in both domains 1 and 2. Considering the relatively high similarity among the five subdomains, they are putative binding sites for galactose-related carbohydrates, although it remains to be elucidated whether bound Ca^ is directly involved in interaction with carbohydrates. The paucity of hydrophobic interactions in the interfaces between the domains and biochemical data suggest that these domains rearrange upon carbohydrate binding in the erythrocyte membrane. This conformational change may be responsible for oligomerization of CEL-III molecules and hemolysis in the erythrocyte membranes.This research was originally published in Journal of Biological Chemistry. Tatsuya Uchida, Takayuki Yamasaki, Seiichiro Eto, Hajime Sugawara, Genji Kurisu, Atsushi Nakagawa, Masami Kusunoki and Tomomitsu Hatakeyama. Crystal structure of the hemolytic lectin CEL-III isolated from the marine invertebrate Cucumaria echinata : Implications of domain structure for its membrane pore-formation mechanism. Journal of Biological Chemistry. 2004; 279, 37133-37141. © the American Society for Biochemistry and Molecular Biology

Efficacy and Safety of Esaxerenone in Hypertensive Patients with Diabetic Kidney Disease: A Multicenter, Open-Label, Prospective Study

Introduction Clinical data of esaxerenone in hypertensive patients with diabetic kidney disease (DKD) are lacking. We evaluated the efficacy and safety of esaxerenone in patients with DKD and an inadequate response to blood pressure (BP)-lowering treatment. Methods In this multicenter, open-label, prospective study, patients were divided into urinary albumin-to-creatinine ratio subcohorts (UACR  Results In total, 113 patients were enrolled. Morning home SBP/DBP significantly decreased from baseline to EOT in the total population (− 11.6/− 5.2 mmHg, both p  Conclusion Esaxerenone demonstrated a BP-lowering effect and improved albuminuria. The effects were consistent regardless of the severity of albuminuria without clinically relevant serum potassium elevation and eGFR reduction

Potential of adenovirus-mediated REIC/Dkk-3 gene therapy for use in the treatment of pancreatic cancer

Background and AimThe reduced expression in immortalized cells REIC/the dickkopf 3 (Dkk-3) gene, tumor suppressor gene, is downregulated in various malignant tumors. In a prostate cancer study, an adenovirus vector carrying the REIC/Dkk-3 gene (Ad-REIC) induces apoptosis. In the current study, we examined the effects of REIC/Dkk-3 gene therapy in pancreatic cancer. MethodsREIC/Dkk-3 expression was assessed by immunoblotting and immunohistochemistry in the pancreatic cancer cell lines (ASPC1, MIAPaCa2, Panc1, BxPC3, SUIT-2, KLM1, and T3M4) and pancreatic cancer tissues. The Ad-REIC agent was used to investigate the apoptotic effect in vitro and antitumor effects in vivo. We also assessed the therapeutic effects of Ad-REIC therapy with gemcitabine. ResultsThe REIC/Dkk-3 expression was lost in the pancreatic cancer cell lines and decreased in pancreatic cancer tissues. Ad-REIC induced apoptosis and inhibited cell growth in the ASPC1 and MIAPaCa2 lines in vitro, and Ad-REIC inhibited tumor growth in the mouse xenograft model using ASPC1 cells. The antitumor effect was further enhanced in combination with gemcitabine. This synergistic effect may be caused by the suppression of autophagy via the enhancement of mammalian target of rapamycin signaling. ConclusionsAd-REIC induces apoptosis and inhibits tumor growth in pancreatic cancer cell lines. REIC/Dkk-3 gene therapy is an attractive therapeutic tool for pancreatic cancer

A metabolome genome-wide association study implicates histidine N-pi-methyltransferase as a key enzyme in N-methylhistidine biosynthesis in Arabidopsis thaliana

A genome-wide association study (GWAS), which uses information on single nucleotide polymorphisms (SNPs) from many accessions, has become a powerful approach to gene identification. A metabolome GWAS (mGWAS), which relies on phenotypic information based on metabolite accumulation, can identify genes that contribute to primary and secondary metabolite contents. In this study, we carried out a mGWAS using seed metabolomic data from Arabidopsis thaliana accessions obtained by liquid chromatography–mass spectrometry to identify SNPs highly associated with the contents of metabolites such as glucosinolates. These SNPs were present in genes known to be involved in glucosinolate biosynthesis, thus confirming the effectiveness of our analysis. We subsequently focused on SNPs detected in an unknown methyltransferase gene associated with N-methylhistidine content. Knockout and overexpression of A. thaliana lines of this gene had significantly decreased and increased N-methylhistidine contents, respectively. We confirmed that the overexpressing line exclusively accumulated histidine methylated at the pi position, not at the tau position. Our findings suggest that the identified methyltransferase gene encodes a key enzyme for N-methylhistidine biosynthesis in A. thaliana

Effects of fly ash on NOx removal by pulsed streamers

NOx removal methods using plasma chemical reactions in nonthermal plasmas have been widely studied. In this paper, the effects of the addition of fly ash on NOx removal using short-pulsed discharge plasmas are described. Fly ash which had been collected from a coal-burning thermal electrical power plant was used. Experiments were performed using four different mixtures of gases which included NO. These were (N2+NO), (N2+NO+O2), (N2+NO+H2O), and (N2+NO+O2+H 2O). These gas mixtures were used either with or without the addition of fly ash. The initial concentration of NO was fixed at 200 ppm (NO parts per million of the gas mixture), The study of the NOx (NO+NO2) removal was performed with the fly ash, as it is relevant to real situations in coal power plants. The results show that the presence of fly ash decreased the NOx removal rate slightly in the case of dry gas mixtures while it increased the NOx removal rate substantially in the case of wet gas mixtures. These results suggest that the presence of fly ash in the flue gases, which also contain a few percentages of moisture, would be advantageous to the treatment of flue gases emitted from thermal power plants for the removal of nitrogen oxides

博士論文要旨 : <秋学期> E. 健康福祉科学研究領域

departmental bulletin pape

Growth of persistent foci of DNA damage checkpoint factors is essential for amplification of G1 checkpoint signaling.

Several DNA damage checkpoint factors form nuclear foci in response to ionizing radiation (IR). Although the number of the initial foci decreases concomitantly with DNA double-strand break repair, some fraction of foci persists. To date, the physiological role of the persistent foci has been poorly understood. Here we examined foci of Ser1981-phosphorylated ATM in normal human diploid cells exposed to 1Gy of X-rays. While the initial foci size was approximately 0.6microm, the one or two of persistent focus (foci) grew, whose diameter reached 1.6microm or more in diameter at 24h after IR. All of the grown persistent foci of phosphorylated ATM colocalized with the persistent foci of Ser139-phosphorylated histone H2AX, MDC1, 53BP1, and NBS1, which also grew similarly. When G0-synchronized normal human cells were released immediately after 1Gy of X-rays and incubated for 24h, the grown large phosphorylated ATM foci (> or =1.6microm) were rarely (av. 0.9%) observed in S phase cells, while smaller foci (<1.6microm) were frequently (av. 45.9%) found. We observed significant phosphorylation of p53 at Ser15 in cells with a single grown phosphorylated ATM focus. Furthermore, persistent inhibition of foci growth of phosphorylated ATM by an ATM inhibitor, KU55933, completely abrogated p53 phosphorylation. Defective growth of the persistent IR-induced foci was observed in primary fibroblasts derived from ataxia-telangiectasia (AT) and Nijmegen breakage syndrome (NBS) patients, which were abnormal in IR-induced G1 checkpoint. These results indicate that the growth of the persistent foci of the DNA damage checkpoint factors plays a pivotal role in G1 arrest, which amplifies G1 checkpoint signals sufficiently for phosphorylating p53 in cells with a limited number of remaining foci

Observations of hard X-rays of auroral origin with Polar Patrol Balloons No. 8 and 10

In the Polar Patrol Balloon (PPB) project, two balloons named PPB-8 and -10 were launched in rapid succession to form a cluster of balloons during their flight on January 13, 2003, from Syowa Station, Antarctica. In order to make the two-dimensional images for auroral X-rays and to obtain the energy spectra of auroras with energy range from 30 keV to 778 keV, the same instruments for hard X-rays were installed on PPB-8 and -10, respectively. These detection systems observed several auroral X-ray events during the flight. In particularly on January 25, 2003, strong auroral events were detected at about 0919 UT by PPB-10 and at 0927 UT by PPB-8. The aurora observed by PPB-10 was observed after about 8 min by PPB-8 located a 650 km west of PPB-10. The energy spectra of the bright aurora at 0919 UT and 0927 UT for PPB-10 and -8 is obtained as E0 = (78+-5) keV and (70+-5) keV, respectively