28 research outputs found
Identification and characterization of an oocyte factor required for development of porcine nuclear transfer embryos.
Nuclear reprogramming of differentiated cells can be induced by oocyte factors. Despite numerous attempts, these factors and mechanisms responsible for successful reprogramming remain elusive. Here, we identify one such factor, necessary for the development of nuclear transfer embryos, using porcine oocyte extracts in which some reprogramming events are recapitulated. After incubating somatic nuclei in oocyte extracts from the metaphase II stage, the oocyte proteins that were specifically and abundantly incorporated into the nuclei were identified by mass spectrometry. Among 25 identified proteins, we especially focused on a multifunctional protein, DJ-1. DJ-1 is present at a high concentration in oocytes from the germinal vesicle stage until embryos at the four-cell stage. Inhibition of DJ-1 function compromises the development of nuclear transfer embryos but not that of fertilized embryos. Microarray analysis of nuclear transfer embryos in which DJ-1 function is inhibited shows perturbed expression of P53 pathway components. In addition, embryonic arrest of nuclear transfer embryos injected with anti-DJ-1 antibody is rescued by P53 inhibition. We conclude that DJ-1 is an oocyte factor that is required for development of nuclear transfer embryos. This study presents a means for identifying natural reprogramming factors in mammalian oocytes and a unique insight into the mechanisms underlying reprogramming by nuclear transfer
The all-particle spectrum of primary cosmic rays in the wide energy range from 10^14 eV to 10^17 eV observed with the Tibet-III air-shower array
We present an updated all-particle energy spectrum of primary cosmic rays in
a wide range from 10^14 eV to 10^17 eV using 5.5 times 10^7 events collected in
the period from 2000 November through 2004 October by the Tibet-III air-shower
array located at 4300 m above sea level (atmospheric depth of 606 g/cm^2). The
size spectrum exhibits a sharp knee at a corresponding primary energy around 4
PeV. This work uses increased statistics and new simulation calculations for
the analysis. We performed extensive Monte Carlo calculations and discuss the
model dependences involved in the final result assuming interaction models of
QGSJET01c and SIBYLL2.1 and primary composition models of heavy dominant (HD)
and proton dominant (PD) ones. Pure proton and pure iron primary models are
also examined as extreme cases. The detector simulation was also made to
improve the accuracy of determining the size of the air showers and the energy
of the primary particle. We confirmed that the all-particle energy spectra
obtained under various plausible model parameters are not significantly
different from each other as expected from the characteristics of the
experiment at the high altitude, where the air showers of the primary energy
around the knee reaches near maximum development and their features are
dominated by electromagnetic components leading to the weak dependence on the
interaction model or the primary mass. This is the highest-statistical and the
best systematics-controlled measurement covering the widest energy range around
the knee energy region.Comment: 19 pages, 20 figures, accepted by Ap
Helical polymer brushes with a preferred-handed helix-sense triggered by a terminal optically active group in the pendant
Insights into the Reaction Mechanism of the Coagulation of Soy Protein Isolates Induced by Subtilisin Carlsberg
Investigation of Proteomic Profiles of Lamina of Ecklonia kurome (Laminariales): Homology-Based Cross-Species Protein Identification and Analysis of the Post-translational Processing of Vanadium-Dependent Bromoperoxidases Using MALDI-TOF/TOF
Proteomic profiles of the lamina of Ecklonia kurome Okamura, one of the Japanese dominant laminarialean kelps, were investigated by two-dimensional electrophoresis (2-DE) and MALDI-TOF/TOF. Due to the absence of E. kurome DNA or protein databases, homology-based cross-species protein identification was performed using a combination of three database-searching algorithms, Mascot peptide mass fingerprinting, Mascot MS/MS ion search, and mass spectrometry-based BLAST. Proteins were extracted from the lamina by an ethanol/phenol method and subjected to 2-DE (pI 4-7, 10 % polyacrylamide gel). More than 700 spots were detected in the 2-DE gel with CBB, and 93 spots (24 proteins) were successfully identified by MALDI-TOF/TOF and the cross-species database searching. The identified proteins mainly consisted of cytoplasmic carbohydrate metabolic enzymes, chloroplast proteins involved in photosynthesis, and haloperoxidases. Interestingly, vanadium-dependent bromoperoxidases (vBPO), which is thought to be involved in halogen uptake, synthesis of halogenated products, and detoxification of reactive oxygen species, were separated into at least 23 different spots. By comparing mass spectra, amino acid sequences predicted from tandem mass spectra and haloperoxidase activities of the vBPOs, we found that (1) at least two types of vBPOs were expressed in the lamina of E. kurome and (2) two pro-vBPOs might be activated by specific cleavage at N- and C-terminal regions
Elucidation of the overall mechanism of metabolic syndrome by high-precision comprehensive protein quantification
SWATH質量分析法は、臓器などに含まれる数百から数千種類のタンパク質を同時に、かつ精密に定量することができる分析手法である。本研究では高脂肪食を5週間摂取させて極初期のメタボリックシンドロームの状態にしたマウスの肝臓や脂肪組織中のタンパク質の網羅的な定量解析を行った。その結果、極初期のメタボロックシンドロームにおいては、糖新生の進行が抑制されており、これが代謝異常の引き金となっている可能性が示され。また、肝臓におけるUSP5やEpiplakin, 脂肪組織におけるASPHなどの新規な肥満関連因子を発見した。SWATH mass spectrometry is an analytical technique that can simultaneously and precisely quantify hundreds to thousands of proteins in organs and other biological samples. In this study, we performed a comprehensive quantitative analysis of proteins in the liver and adipose tissue of mice that were fed a high-fat diet for 5 weeks and were in a state of very early metabolic syndrome. The results showed that the progression of glycogenesis is suppressed in the very early stage of the metabolic syndrome, which may trigger the metabolic abnormalities. We also found novel obesity-related factors such as USP5 and Epiplakin in the liver and ASPH in adipose tissue.研究分野:プロテオミク
A case of minor BCR-ABL1 positive acute lymphoblastic leukemia following essential thrombocythemia and originating from a clone distinct from that harboring the JAK2-V617F mutation.
Here we report on a case of Philadelphia chromosome positive B lymphoblastic leukemia (Ph+ALL), which developed following a long duration of essential thrombocythemia (ET). A mutational analysis of Janus Kinase 2 (JAK2) revealed that the V617F mutation was present in granulocytes and in hematopoietic stem and progenitor cells (HSPCs), but not in the CD34+CD19+ population that mostly consists of Ph+ALL cells, indicating that this Ph+ALL clone did not originate from the ET clone carrying the JAK2-V617F mutation. The minor BCR-ABL1 fusion was detected not only in the CD34+CD19+ population but also in HSPCs and granulocytes, indicating that the Philadelphia chromosome was acquired in an early hematopoietic stage at least prior to the commitment to B cell development. Upon dasatinib treatment, the minor BCR-ABL1 transcript rapidly disappeared in HSPCs but persisted in the CD34+CD19+ population. A relapse of Ph+ALL occurred nine months later without the disappearance of the minor BCR-ABL1 transcript in the bone marrow cells during the treatment course, suggesting that a resistant Ph+ALL clone may have arisen or been selected in the committed B cells rather than in HSPCs. This case report may partly contribute to filling the gap between previous data acquired from mice experiments and the phenomenon in real patients
Inhibitory effects of resistant maltodextrin on rat disaccharidases: Overestimation by the method measuring released glucose
Resistant maltodextrin (RMD) attenuates the blood glucose response in healthy adults, as supported by meta-analysis. One of the potential mechanisms is disaccharidase inhibition. We hypothesized that the conventional method determining released glucose might lead to misestimation of the inhibitory effects because RMD is partly digested and the glucose amount released from RMD could change in the presence or absence of substrates. We examined digestibility change of RMD and compared the inhibitory effects by determination of released glucose (Glu method), fructose (Fru method), and p-nitrophenol from p-nitrophenyl- α -D-glucopyranoside (pNPG method). The Glu method overestimated the inhibition rate (18.9 to 60.2% for maltase). The Fru method showed inhibition for sucrase by 6.46 to 10.9% and isomaltase by 14.4 to 28.6%. The pNPG method showed α-glucosidase inhibition of 11.0 to 28.1%. These results indicate that the Glu method is not suitable for inhibition assay of partially digestible dextrin and that RMD has disaccharidase inhibition