In Vivo Generation of Engraftable Murine Hematopoietic Stem Cells by Gfi1b, c-Fos, and Gata2 Overexpression within Teratoma.

Generation of hematopoietic stem cells (HSCs) from pluripotent stem cells (PSCs) could potentially provide unlimited HSCs for clinical transplantation, a curative treatment for numerous blood diseases. However, to date, bona fide HSC generation has been largely unsuccessful in vitro. We have previously described proof of concept for in vivo HSC generation from PSCs via teratoma formation. However, our first-generation system was complex and the output low. Here, we further optimize this technology and demonstrate the following: (1) simplified HSC generation using transcription factor overexpression; (2) improved HSC output using c-Kit-deficient host mice, and (3) that teratomas can be transplanted and cryopreserved. We demonstrate that overexpression of Gfi1b, c-Fos, and Gata2, previously reported to transdifferentiate fibroblasts into hematopoietic progenitors in vitro, can induce long-term HSC formation in vivo. Our in vivo system provides a useful platform to investigate new strategies and re-evaluate existing strategies to generate HSCs and study HSC development

Enhanced expression of complement regulatory proteins on thyroid epithelial cells of Graves' disease.

Cytotoxic anti-thyroid microsomal autoantibodies are highly prevalent in sera of patients with Graves' disease, but in Graves' disease thyroid tissues rarely show destructive changes. We postulated that this might be due to membrane-associated complement regulatory proteins which protect target cells from injury by complement activation. We, therefore, investigated the expression of membrane attack complex inhibitory factor (MACIF) and decay accelerating factor (DAF) in the thyroid tissues from patients with Graves' disease, Hashimoto's thyroiditis, thyroid adenocarcinoma and normal human thyroid tissues. We found a high level of expression of MACIF and DAF in Graves' thyroid tissues. Using the membrane immunofluorescence and cell-ELISA techniques, we also investigated the factors which enhanced the MACIF and DAF expression in cultured thyroid cells. Thyroid stimulating hormone, phorbol 12, 13-dibutyrate and thyroid stimulating autoantibody enhanced the MACIF and DAF expression. These findings suggest that the membrane complement regulatory proteins increase in response to the thyroid stimulating factors such as thyroid stimulating autoantibody in Graves' disease and that this increase then protects the cells from damage due to complement activation by thyroid autoantibodies.</p

ポライトネス及び配慮表現コーパス作成と分析手法の一考察 : 対人関係を考慮した対話システムの適用に向けて

The Open University of Japan会議名: 言語資源活用ワークショップ2019, 開催地: 国立国語研究所, 会期: 2019年9月2日−4日, 主催: 国立国語研究所 コーパス開発センター昨今、ディープラーニングを中心とした機械学習の進展が見受けられ、従来の画像処理・音声認識・自然言語処理の3分野での進展、とりわけ、機械翻訳での取り組みにおいて、言語学や社会学からポライトネスや配慮表現が取り込まれることで、技術面での質的向上が図られようとしている。従来のQ&Aのような対話応答から、対人関係を配慮した対話応答の取り組みは、必要不可欠である。ここで、機械学習への配慮表現の適用は、教師ありデータとして準備する必要があり、PJ上、時間を要するものである。そこで、本稿では、ポライトネスもしくは、配慮行動や配慮表現を主とした機械翻訳や対話文生成の基となる小規模なデータベース（またはコーパス）を構築し、先行研究の多様な定義や議論を踏まえて場面別の発話ストラテジーの傾向を簡易なベイズ論的アプローチで試みたものである。既存のコーパスと対話システム・機械翻訳との懸け橋になればと考えている

日本語学習者属性別の言語行為の対話自動生成への適用に関する一考察

The Open University of Japan会議名: 言語資源活用ワークショップ2018, 開催地: 国立国語研究所, 会期: 2018年9月4日-5日, 主催: 国立国語研究所 コーパス開発センター最近，自然言語処理における対話システムや対話生成が注目されている．チャットボットのコールセンターへの普及により，正確な人間性な対話応答が求められている．一方，社会学のエスノメソドロジーや談話分析・会話分析における定性的な相互行為は有益である．そこで，もう一度，国立国語研究所の提供する日本語学習者会話データコーパスを用いて，効果を検証し対話破綻の傾向や対話生成に適用することを目指した考察である

Identification of the X-linked germ cell specific miRNAs (XmiRs) and their functions

<div><p>MicroRNAs (miRNAs) play a critical role in multiple aspects of biology. Dicer, an RNase III endonuclease, is essential for the biogenesis of miRNAs, and the germ cell-specific <i>Dicer1</i> knockout mouse shows severe defects in gametogenesis. How miRNAs regulate germ cell development is still not fully understood. In this study, we identified germ cell-specific miRNAs (miR-741-3p, miR-871-3p, miR-880-3p) by analyzing published RNA-seq data of mouse. These miRNA genes are contiguously located on the X chromosome near other miRNA genes. We named them X chromosome-linked miRNAs (XmiRs). To elucidate the functions of XmiRs, we generated knockout mice of these miRNA genes using the CRISPR/Cas9-mediated genome editing system. Although no histological abnormalities were observed in testes of F0 mice in which each miRNA gene was disrupted, a deletion covering <i>miR-871</i> and <i>miR-880</i> or covering all <i>XmiRs</i> (<i>ΔXmiRs</i>) resulted in arrested spermatogenesis in meiosis in a few seminiferous tubules, indicating their redundant functions in spermatogenesis. Among candidate targets of XmiRs, we found increased expression of a gene encoding a WNT receptor, FZD4, in <i>ΔXmiRs</i> testis compared with that in wildtype testis. miR-871-3p and miR-880-3p repressed the expression of <i>Fzd4</i> via the 3′-untranslated region of its mRNA. In addition, downstream genes of the WNT/β-catenin pathway were upregulated in <i>ΔXmiRs</i> testis. We also found that <i>miR-871</i>, <i>miR-880</i>, and <i>Fzd4</i> were expressed in spermatogonia, spermatocytes and spermatids, and overexpression of <i>miR-871</i> and <i>miR-880</i> in germ stem cells in culture repressed their increase in number and <i>Fzd4</i> expression. Previous studies indicated that the WNT/β-catenin pathway enhances and represses proliferation and differentiation of spermatogonia, respectively, and our results consistently showed that stable β-catenin enhanced GSC number. In addition, stable β-catenin partially rescued reduced GSC number by overexpression of <i>miR-871</i> and <i>miR-880</i>. The results together suggest that <i>miR-871</i> and <i>miR-880</i> cooperatively regulate the WNT/β-catenin pathway during testicular germ cell development.</p></div

A safeguard system for induced pluripotent stem cell-derived rejuvenated T cell therapy

The discovery of induced pluripotent stem cells (iPSCs) has created promising new avenues for therapies in regenerative medicine. However, the tumorigenic potential of undifferentiated iPSCs is a major safety concern for clinical translation. To address this issue, we demonstrated the efficacy of suicide gene therapy by introducing inducible caspase-9 (iC9) into iPSCs. Activation of iC9 with a specific chemical inducer of dimerization (CID) initiates a caspase cascade that eliminates iPSCs and tumors originated from iPSCs. We introduced this iC9/CID safeguard system into a previously reported iPSC-derived, rejuvenated cytotoxic T lymphocyte (rejCTL) therapy model and confirmed that we can generate rejCTLs from iPSCs expressing high levels of iC9 without disturbing antigen-specific killing activity. iC9-expressing rejCTLs exert antitumor effects in vivo. The system efficiently and safely induces apoptosis in these rejCTLs. These results unite to suggest that the iC9/CID safeguard system is a promising tool for future iPSC-mediated approaches to clinical therapy

Development of Gas Multiplier Counters (GMCs) Onboard the 6U CubeSat X-Ray Observatory NinjaSat

We report the development of Gas Multiplier Counters (GMCs) onboard the 6U CubeSat X-ray observatory NinjaSat, scheduled to be launched in October 2023. GMC is a 1U-size non-imaging gas X-ray detector sensitive to 2–50 keV X-rays, and two identical GMCs are mounted on NinjaSat. GMC consists of a gas cell filled with a xenon/argon/dimethyl ether (75%/24%/1%) gas mixture with a pressure of 1.2 atm at 0◦C, a high voltage supply and analog signal processing board, a digital signal processing board, an X-ray collimator of a 2.1◦ field of view, and an iron-55 calibration source. The most significant feature of the GMC is its large effective area of 32 cm2 at 6 keV, which is more than two orders of magnitude larger than the X-ray detectors onboard previously launched CubeSats. We have achieved this at a low cost and in a short development time by employing a gas detector that can easily increase its effective area and using a space-proven gas electron multiplier. GMC was characterized with X-rays from an X-ray generator in a laboratory and monochromatic X-rays on the BL-14A beamline at the KEK synchrotron radiation facility. In this paper, we present the design of GMC and the preliminary results of the detector calibration

NinjaSat: 6U CubeSat Observatory for Bright X-Ray Sources

NinjaSat is a 6U CubeSat observatory designed for long-term monitoring of bright X-ray sources, such as binary systems between normal stars and black holes or neutron stars. NinjaSat is the first Japanese CubeSat dedicated to astronomical observation, and it is also a mission to demonstrate that even a small satellite, which can be developed quickly and inexpensively, unlike large satellites, can perform excellent scientific observations. NinjaSat realizes the world’s highest X-ray sensitivity in CubeSat missions by using gas X-ray detectors filling the entire space allocated for science payloads. The fabrication of the flight model payloads began in 2021, and testing at the payload component level was completed in August 2022; as of April 2023, the payloads were integrated into the Nano Avionics 6U bus (M6P) in Lithuania. After four months of testing, the payload will be stored in the Exolaunch deployer in August and launched by the SpaceX Transporter-9 mission in October 2023. This paper will describe the scientific objectives, satellite structure, payloads, and operations of NinjaSat

Development of Radiation Belt Monitors for the 6U CubeSat X-Ray Observatory NinjaSat

NinjaSat is a 6U CubeSat-sized X-ray observatory to be launched into the low Earth orbit at an altitude of 550 km, and is scheduled for launch this October. NinjaSat is equipped with two 1U-sized gas X-ray detectors (GMC) and is expected to operate mainly for astronomical observations of bright X-ray objects in the sky, such as neutron stars and black holes. Since high voltages are applied to the gas cells of GMC, two radiation belt monitors (RBM) will also be installed to protect GMC from electrical discharges potentially caused by excessively high rate of charged particles. NinjaSat RBM will play a fail-safe function in the voltage suppression operation of GMC in the auroral zone and South Atlantic Anomaly, and also protect GMC from charged particles such as protons and electrons that arrive unexpectedly due to solar flares or other low-Earth orbit radiation events. RBM uses a 9 mm x 9 mm Si-PIN photodiode as a charged particle sensor. By taking advantage of the difference in sensor response to protons and electrons, the sensor is designed to simultaneously count charged particle rates at multiple energy thresholds so that GMC protection function will operate even if either the proton or electron rate increases. RBM can count up to about 10 kcps with almost no loss of counts, and proton beam tests have confirmed that the response performance is sufficient to protect GMC against excessively high charged particle rates above 10 Mcps without choking the circuitry. The flight models of the RBM have passed the thermal vacuum and vibration tests last year. The developed RBM occupies only about 6% of the 1U CubeSat size in volume and weighs only 70g. In addition, since the RBM uses inexpensive, commercially available sensors, it could be installed on small satellites other than NinjaSat with relatively small development resources