研究者業績

小林 達也

Tatsuya Kobayashi

基本情報

所属
藤田医科大学 医療科学部 レギュラトリーサイエンス分野 准教授
(兼任)リプロダクションセンター 培養室長
千葉大学大学院医学研究院 病原細菌制御学 特任助教
学位
博士(千葉大学)

J-GLOBAL ID
201801011446410687
researchmap会員ID
B000347319

論文

 29
  • Hiroshi Ishikawa, Yuki Goto, Chigusa Hirooka, Eri Katayama, Nao Baba, Meika Kaneko, Yoshiko Saito, Tatsuya Kobayashi, Kaori Koga
    Journal of reproductive immunology 165 104317-104317 2024年8月15日  
    Uterine fibroids (UFs), the most common tumors in women of reproductive age, are characterized by sex steroid-dependent growth and excessive deposition of extracellular matrix (ECM) surrounding UF smooth muscle cells. Women with symptomatic UFs experience heavy menstrual bleeding and consequent iron-deficiency anemia. They also have a risk of recurrent pregnancy loss, preterm birth, and cesarean delivery, indicating that UFs can negatively affect reproductive outcomes. Various types of immune cells, including innate and adaptive cells, are observed in UFs; however, the impact of these cells on the pathophysiology of UFs remains unclear. Inflammation may play important roles in the growth of UFs, and expression levels of proinflammatory and inflammatory cytokines, such as interleukin (IL)-1, IL-6, IL-10, TNF-α, and TGF-β, are upregulated in UFs. These cytokines play important roles in the interaction between growth factors and ECM that is regulated by the sex steroids estrogen and progesterone. Furthermore, proinflammatory mediators are upregulated in females with UFs, with higher expression levels in the endometrium with submucosal and intramural UFs than in the endometrium without UFs, indicating that these proinflammatory cytokines may impair endometrial receptivity, leading to implantation failure in in vitro fertilization programs. Hormonal treatments using gonadotropin releasing hormone analogs and the selective progesterone receptor modulator ulipristal acetate significantly shrink UFs and improve UF-related symptoms. These compounds can regulate local inflammation in UFs and adjacent myometrium. Controlling and improving local inflammation caused by UFs may represent a novel therapeutic strategy for UFs and potentially improve reproductive outcomes in women with symptomatic UFs.
  • Hongying Piao, Hiroshi Ishikawa, Tatsuya Kobayashi, Keiko Kitajo, Atsushi Yamaguchi, Kaori Koga, Makio Shozu
    Pediatrics & Neonatology 2024年8月  
  • Masashi Shioya, Miki Okabe-Kinoshita, Tatsuya Kobayashi, Maki Fujita, Keiichi Takahashi
    Journal of Assisted Reproduction and Genetics 2024年3月19日  
  • Hiroshi Ishikawa, Tatsuya Kobayashi, Meika Kaneko, Yoshiko Saito, Makio Shozu, Kaori Koga
    Journal of molecular endocrinology 2023年9月1日  
    Uterine fibroids (UFs) are benign tumors arising from the uterus, characterized by accumulation of abundant extracellular matrix (ECM) and sex steroids dependent growth. Women with symptomatic UFs have reduced quality of life and decreased labor productivity. Among the driver gene mutations identified in UFs, mutations in MED12, a component of the cyclin-dependent kinase (CDK) Mediator module, are the most common and observed in 50-80% of UFs. They are gain-of-function mutations and are more frequently observed in Black women and commonly observed even in small UFs. MED12 mutation-positive UFs (MED12-UFs) often develop multiple rather than solitary UFs and have distinct gene expression profiles, DNA methylomes, transcriptomes, and proteomes. Gene expressions related to ECM organization and collagen-rich ECM components are upregulated, and impaired Mediator kinase activity and dysregulation of Wnt/β-catenin signaling are identified in MED12-UFs. Clinically, the UF shrinking effect of gonadotropin-releasing hormone agonists and ulipristal acetate is dependent on the MED12 mutation status. Understanding of characteristics of MED12-UFs and functions of MED12 mutations for UF tumorigenesis may elucidate the pathophysiology of UFs, leading to the development of new therapeutic options in women with symptomatic UFs.
  • 中田 恵美里, 宇津野 恵美, 杉山 淳比古, 澤井 摂, 小林 達也, 碓井 宏和, 市川 智彦
    日本遺伝カウンセリング学会誌 44(1) 13-17 2023年5月  査読有り
    背景:デュシェンヌ/ベッカー型筋ジストロフィー(DMD/BMD)はともにX染色体上のジストロフィン遺伝子変異を原因とする遺伝性疾患だが,DMDはフレームシフト/ナンセンス変異により若年発症し進行が速い。出生前/着床前診断の対象となりうるためBMDとの鑑別は重要である。症例:11歳女児,ジストロフィン遺伝子のサザンブロット解析でin-frame欠失を認め,BMD保因者であることが示唆された。29歳時,挙児希望にて周産期遺伝カウンセリング目的に来院。MLPA再解析でout-of-frame欠失を認め,DMD保因者であることが示唆された。考察:遺伝子解析方法により欠失領域の判定が異なる結果となった症例を経験した。解析方法の進歩によって,過去の検査結果や解釈が変化することがある。結論:欠失領域の判定は筋ジストロフィーのタイプに直接関係する。周産期遺伝カウンセリングにおいては注意が必要である。(著者抄録)
  • Tsuyoshi Okubo, Noriyuki Onda, Teruaki Hayashi, Tatsuya Kobayashi, Kenji Omi, Tomoya Segawa
    BMC urology 23(1) 78-78 2023年4月29日  査読有り
    BACKGROUND: We analyzed the sperm DNA fragmentation index (DFI) and general semen test based on the World Health Organization (WHO) criteria and compared the two tests using semen factors. In addition, we examined whether DFI is a reliable parameter associated with in vitro fertilization (IVF) outcomes. METHODS: Sperm chromatin dispersion (SCD) and general semen tests were conducted in accordance with the WHO 2010 guidelines, and correlations between the two tests were investigated. The WHO criteria were set as the cutoff values for each of the following factors: semen volume, concentration, total sperm count, motility, and normal morphology, and compared with the DFI results. RESULTS: The subjects had a mean sperm DFI of 15.3% ± 12.6%, and the DFI increased with age. In contrast, motility and normal morphology decreased as the DFI increased. Patients who satisfied the WHO criteria in terms of concentration, total sperm count, and motility had a significantly lower DFI than those who did not satisfy the criteria. Therefore, evaluation with a general semen test based on the WHO criteria should be regarded as a qualitative evaluation of all factors other than semen volume and normal morphology. CONCLUSIONS: High DFI (≥ 30%) caused a low blastocyst development rate following intracytoplasmic sperm injection. Male infertility due to DFI should be suspected when IVF results are poor despite normal semen findings based on the WHO criteria. The results of this study suggest that the SCD test may more accurately evaluate the correlation between IVF clinical outcomes and male infertility. Therefore, it is important to focus on DFI measurements.
  • 小林 達也, 石川 博士, 田中 宏一, 石井 久美子, 三橋 暁, 生水 真紀夫, 碓井 宏和, 甲賀 かをり
    Journal of Mammalian Ova Research 40(1) S28-S28 2023年4月  
  • 塩谷 仁之, 小林 達也, 杉浦 朝治, 岡部 美紀, 藤田 真紀, 高橋 敬一
    日本受精着床学会雑誌 40(1) 33-40 2023年3月  
    iDAScoreの値と臨床妊娠(胎児心拍の有無)との関係を解析し、移植胚選択におけるiDAScoreの有用性について検証するとともに、Grade AA胚においてもより妊娠率の高い胚を選択することができるか検討した。対象は当院で2019~2021年に単一凍結融解胚移植に使用した胚盤胞655個とした。解析の結果、移植胚全体(Grade CC~AAの胚盤胞)においてiDAScore値の上昇に伴う妊娠率の有意な上昇が認められた。Grade AA胚のみを対象とした解析でもiDAScore値の上昇に伴う妊娠率の有意な上昇が認められた。これらの結果からiDAScoreは移植胚選択に有用であることが確認され、Grade AA胚の中からさらに妊娠能の高い胚盤胞を選択することも可能であると考えられた。
  • 塩谷 仁之, 小林 達也, 杉浦 朝治, 岡部 美紀, 藤田 真紀, 高橋 敬一
    日本受精着床学会雑誌 40(1) 33-40 2023年3月  査読有り
    iDAScoreの値と臨床妊娠(胎児心拍の有無)との関係を解析し、移植胚選択におけるiDAScoreの有用性について検証するとともに、Grade AA胚においてもより妊娠率の高い胚を選択することができるか検討した。対象は当院で2019~2021年に単一凍結融解胚移植に使用した胚盤胞655個とした。解析の結果、移植胚全体(Grade CC~AAの胚盤胞)においてiDAScore値の上昇に伴う妊娠率の有意な上昇が認められた。Grade AA胚のみを対象とした解析でもiDAScore値の上昇に伴う妊娠率の有意な上昇が認められた。これらの結果からiDAScoreは移植胚選択に有用であることが確認され、Grade AA胚の中からさらに妊娠能の高い胚盤胞を選択することも可能であると考えられた。
  • Tatsuya Kobayashi, Kyoko Nishikimi, Akira Mitsuhashi, Hongying Piao, Ayumu Matsuoka, Satoyo Otsuka, Shinichi Tate, Makio Shozu, Hirokazu Usui
    Genes, chromosomes & cancer 2023年1月29日  査読有り筆頭著者責任著者
    Several cancers harbor "enhancer-type" mutations of the telomerase reverse transcriptase (TERT) promoter for immortalization. Here, we report that 8.6% (8/93) of ovarian clear cell carcinomas (OCCCs) possess the "suppressor-type" TERT promoter mutation. The recurrence rate of OCCCs with "suppressor-type" TERT promoter mutations was 62.5% (5 of 8) and was significantly higher than that of the "unaffected-type" with no mutation (20.8%, 15 of 72) or "enhancer-type" TERT promoter mutations (7.7%, 1 of 13). Our findings show that the acquired suppression of TERT is closely associated with OCCC development and recurrence, indicating the need for further research on telomerase suppression in cancers.
  • 渡辺 慶, 小林 達也, 岡部 美紀, 中野俊 明石佐奈子, 山内久美子, 塩谷 仁之, 東野 志保, 杉浦 朝治, 小島 勝志, 岡田 裕美子, 藤田 真紀, 高橋 敬一
    日本受精着床学会雑誌 39(2) 225-260 2022年11月  査読有り
    当院では凍結融解胚移植を行う際に、凍結保存されている胚が0PN由来胚のみ、もしくは1PN由来胚のみであった場合、夫婦の同意を得たうえで胚移植を実施してきた。今回、2009~2020年に単一凍結融解胚盤胞移植を行った0PN由来胚291周期と1PN由来胚93周期の移植成績を2PN胚移植群と比較することで、異常受精胚の有用性と安全性について検討した。結果、胚移植あたりの妊娠率は0PN群が47.4%、1PN群が39.8%、2PN群が43.3%であり、OPN群・1PN群とも2PN群と有意差はなかった。流産率はそれぞれ27.5%、35.1%、21.4%であり、0PN群は2PN群と有意差なく、1PN群は2PN群に比べて有意に高かった。妊娠継続率はそれぞれ34.4%、25.8%、34.2%であり、0PN群・1PN群とも2PN群と有意差はなかった。ロジスティック回帰分析により患者および胚の背景を考慮した場合、0PN胚は2PN胚に比べて妊娠に至る可能性が有意に高く、1PNの流産に対する影響は減弱した。出産後調査が行えた0PN由来胚移植例78例と1PN由来胚移植例22例について新生児奇形の有無を調べた結果、0PN胚移植群で停留睾丸を1例に認めた。
  • Ayumu Matsuoka, Shinichi Tate, Kyoko Nishikimi, Tastuya Kobayashi, Satoyo Otsuka, Makio Shozu
    Cancers 14(18) 2022年9月15日  査読有り
    BACKGROUND: We evaluated whether the serum hormone levels are useful in the differential diagnosis of granulosa cell tumors (GCTs), regardless of menopausal status. METHODS: Serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, estradiol, and progesterone were measured preoperatively in all patients (n = 471) who underwent surgery for ovarian tumors at Chiba University Hospital between 2009 and 2021. These were compared in two groups, a GCT group (n = 13) and a group with other histological types (non-GCT) (n = 458). RESULTS: The GCT group had significantly lower serum LH and FSH (p = 0.03 and p < 0.001, respectively) and significantly higher testosterone, estradiol, and progesterone (p < 0.001, p < 0.001, and p = 0.045, respectively) than the non-GCT group. Multivariate analysis revealed that serum FSH and estradiol were significantly associated with GCT (FSH, odds ratio (OR) = 0.0046, 95% confidence interval (CI) = 0.0026-0.22, p = 0.004; estradiol, OR = 0.98, 95% CI = 0.96-0.998, p = 0.046). Receiver-operating characteristic curve analysis for GCTs showed that the area under the curve of serum FSH was 0.99, with a sensitivity of 100% and a specificity of 98%, when the cutoff level was set at 2.0 IU/L. CONCLUSIONS: Preoperative serum FSH level is an extremely useful marker for differentiating GCTs from all ovarian tumors.
  • Shintaro Oka, Haruka Matsukuma, Naoya Horiguchi, Tatsuya Kobayashi, Koji Shiraishi
    Molecular and cellular endocrinology 111766-111766 2022年9月5日  査読有り
    An appropriate balance between testicular testosterone and estradiol is required for spermatogenesis. Excess estradiol is often identified in the semen and serum of infertile men; however, the mechanisms behind this observation remain unclear. This study indicates the relationship between heat stress and aromatase synthesis in Leydig cells. We used R2C rat Leydig tumor cells, which can synthesize both testosterone and estradiol. Aromatase transcription was regulated by the PⅡ promoter with or without heat stress. Heat stress at 40 °C increased aromatase expression and decreased testosterone to estradiol ratio and nuclear DAX-1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1), which is a suppressor of steroidogenic factor 1 (SF-1). Leptomycin B and KPT-185, a nuclear export inhibitor, prevented nuclear DAX-1 deficiency induced by heat stress and inhibited aromatase transcription. These results indicate that heat stress interferes with DAX-1-SF-1 interaction and induces SF-1-dependent aromatase transcription.
  • Wenjing Gu, Akira Mitsuhashi, Tatsuya Kobayashi, Makio Shozu
    BMC cancer 22(1) 753-753 2022年7月11日  査読有り
    BACKGROUND: Progestin is used for fertility-sparing treatment in cases of endometrial cancer (EC). Progestin can induce hyperprolactinemia by increasing pituitary secretion and endometrial decidualization. However, progestin induces prolactin (PRL) secretion, which stimulates cell proliferation and deleteriously affects treatment. To date, the detrimental effect of PRL, the secretion of which is induced by medroxyprogesterone acetate (MPA) during fertility-sparing treatment, has not yet been fully elucidated. Therefore, we aimed to assess the effects of PRL on EC cells during combined treatment with progestin and metformin. METHODS: In total, 71 patients with EC/endometrial atypical hyperplasia who underwent fertility-sparing treatment at our institution from 2009-2019 were enrolled. Serum PRL levels were determined using enzyme immunoassays; mRNA levels in endometrial tissues were determined using quantitative reverse-transcription PCR. To evaluate MPA-induced decidualization, cancer-associated stromal cells were enzymatically released from surgically removed specimens of six patients with EC. To examine PRL-induced cell proliferation, the EC cell lines Ishikawa, HEC1B, and HEC265 were used. In vitro cell proliferation was evaluated using the WST assay; protein levels of signaling molecules were determined using western blotting. RESULTS: MPA administration significantly increased serum PRL levels at 3 and 6 months and upregulated IGFBP-1 and PRL mRNA expression in tissues at 3 months of fertility-sparing treatment. Metformin significantly reduced MPA-induced IGFBP-1 and PRL mRNA expression during fertility-sparing treatment and significantly inhibited the upregulation of IGFBP-1 and PRL mRNA and PRL levels due to decidualization induced by MPA and cAMP treatment in primary cultured EC stromal cells. In vitro, PRL increased cell proliferation and ERK1/2 phosphorylation levels, whereas metformin attenuated these increases. CONCLUSIONS: MPA upregulated PRL levels in serum and endometrial tissues during fertility-sparing treatment. Metformin co-administration reduced PRL production and attenuated PRL-induced cell-proliferation activity. This study may provide valuable insights on the application of metformin to improve the outcomes of fertility-sparing treatment.
  • Tatsuya Kobayashi, Akira Mitsuhashi, Piao Hongying, Masashi Shioya, Katsushi Kojima, Kyoko Nishikimi, Kinnosuke Yahiro, Makio Shozu
    Scientific reports 12(1) 11123-11123 2022年7月1日  査読有り筆頭著者
    Bexarotene selectively activates retinoid X receptor, which is a commonly used anticancer agent for cutaneous T-cell lymphoma. In this study, we aimed to investigate the anticancer effect of bexarotene and its underlying mechanism in ovarian cancer in vitro. The ES2 and NIH:OVACAR3 ovarian cancer cell lines were treated with 0, 5, 10, or 20 µM of bexarotene. After 24 h, cell number measurement and lactate dehydrogenase (LDH) cytotoxicity assay were performed. The effect of bexarotene on CDKN1A expression, cell cycle-related protein, cell cycle, pyroptosis, and apoptosis was evaluated. Bexarotene reduced cell proliferation in all concentrations in both the cells. At concentrations of > 10 µM, extracellular LDH activity increased with cell rupture. Treatment using 10 µM of bexarotene increased CDKN1A mRNA levels, decreased cell cycle-related protein expression, and increased the sub-G1 cell population in both cells. In ES2 cells, caspase-4 and GSDME were activated, whereas caspase-3 was not, indicating that bexarotene-induced cell death might be pyroptosis. A clinical setting concentration of bexarotene induced cell death through caspase-4-mediated pyroptosis in ovarian cancer cell lines. Thus, bexarotene may serve as a novel therapeutic agent for ovarian cancer.
  • Linlin Xu, Hiroshi Ishikawa, Yanruo Zhou, Tatsuya Kobayashi, Makio Shozu
    F&S science 3(2) 187-196 2022年5月  査読有り
    OBJECTIVE: To investigate the antitumor effects of the selective hypoxia-inducible factor-1 (HIF-1) inhibitors echinomycin and PX-478 on uterine fibroids. DESIGN: Experimental study using in vitro primary culture systems and an in vivo mouse xenograft model. SETTING: Academic university center. PATIENT(S): Women with uterine fibroids who underwent hysterectomy or myomectomy. INTERVENTION(S): Administration of the selective HIF-1 inhibitors echinomycin and PX-478 to the media of the primary cultured uterine fibroid cells and to nonobese diabetic/severe combined immunodeficient mice bearing fibroid xenografts consisting of the primary cultured fibroid cells and type Ⅰ collagen gels beneath the kidney capsule. MAIN OUTCOME MEASURE(S): Cell proliferation was measured by Cell Counting Kit-8 assay. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay and by measuring caspase 3 and 7 activities. The xenografts were evaluated by gross appearance, surface area, and histology. The Ki-67 index was measured to evaluate proliferation of the xenografts. RESULT(S): Both echinomycin and PX-478 inhibited cell proliferation and induced apoptosis in fibroid cells cultured under hypoxia and normoxia. Enlargement of the fibroid xenografts was significantly attenuated. The Ki-67 index significantly decreased after the administration of the HIF-1 inhibitors in the xenograft model. Eight of 27 xenografts treated with the HIF-1 inhibitors contained calcification and hyalinizing components from 3 days after the grafting to 2 weeks, suggesting that the HIF-inhibitors induce degeneration of the fibroid xenografts. CONCLUSION(S): The selective HIF-1 inhibitors echinomycin and PX-478 show antitumor effects against uterine fibroids both in vitro and in vivo. These findings support the potential use of HIF-1 inhibitors for the treatment of uterine fibroids.
  • Miki Okabe-Kinoshita, Tatsuya Kobayashi, Masashi Shioya, Tomoharu Sugiura, Maki Fujita, Keiichi Takahashi
    Journal of assisted reproduction and genetics 2022年4月25日  査読有り責任著者
    PURPOSE: To determine whether granulocyte-macrophage colony-stimulating factor (GM-CSF)-containing medium could improve embryo-transfer outcomes in frozen-thawed blastocyst transfer. METHODS: Patients who underwent frozen-thawed blastocyst transfer (430 women, aged 30-39 years, 566 cycles) were analyzed. Frozen-thawed blastocysts were cultured in GM-CSF-containing medium or control medium for 3-5 h, followed by transfer to the uterus. The embryo-transfer outcomes in the two groups were measured and compared, and a propensity score matching (1:1) method was used to balance the differences in baseline characteristics. We analyzed 213 matched samples. RESULTS: In patients who underwent frozen-thawed blastocyst transfer with GM-CSF, the percentage of human chorionic gonadotropin-positive cases, biochemical pregnancies, clinical pregnancies, ongoing pregnancies, and live birth rates was 60.6%, 7.98%, 52.6%, 42.9%, and 40.9%, respectively, as compared with 45.1%, 3.29%, 41.8%, 31.1%, and 30.5%, respectively, for the control groups. The rates of human chorionic gonadotropin positivity (odds ratio [OR]: 1.87, 95% confidence interval: [CI]: 1.27-2.75), biochemical pregnancy (2.55, 1.04-6.29), clinical pregnancy (1.54, 1.05-2.27), ongoing pregnancy (1.64, 1.13-2.41), and live birth (1.67, 1.14-2.45) were significantly higher in the GM-CSF group than the control group. The incidence of pregnancy loss (22.3% vs. 27.0%) did not significantly differ between the groups. CONCLUSION: The use of a GM-CSF-containing medium for blastocyst-recovery culture improved the live birth rate as a result of increased implantation rate in the frozen-thawed blastocyst-transfer cycle. The use of GM-CSF-containing medium following blastocyst thawing could be an effective choice for improving the blastocyst-transfer outcomes.
  • Masashi Shioya, Tatsuya Kobayashi, Tomoharu Sugiura, Maki Fujita, Keiichi Takahashi
    Reproductive Medicine and Biology 2022年1月  査読有り
  • Tatsuya Kobayashi, Hiroshi Ishikawa, Kumiko Ishii, Asuka Sato, Natsuko Nakamura, Yoshiko Saito, Hisataka Hasegawa, Maki Fujita, Akira Mitsuhashi, Makio Shozu
    Scientific reports 11(1) 18862-18862 2021年9月22日  査読有り筆頭著者責任著者
    We aimed to investigate why the incidence of embryos derived from oocytes with no pronuclei (0PN) decreases using time-lapse monitoring (TLM) versus fixed-point assessment in conventional IVF cycles. We analyzed 514 embryos monitored with TLM 6-9 h after insemination and 144 embryos monitored using microscopic assessment 18-21 h after insemination. The primary endpoint of this study was the incidence of 0PN-derived embryos in short insemination followed by TLM. The secondary endpoint was the duration of insemination. As exploratory endpoints, we analyzed the blastulation rate and cryo-warmed blastocyst transfer outcome of embryos with early PN fading, whereby PN disappeared within < 20 h following the initiation of insemination. The incidence of 0PN-derived embryo reduced more significantly through TLM than through fixed-point observation. The microscopic assessment time was more significantly delayed in the 0PN-derived embryo than that in the 2PN-derived embryo. The embryo with early PN fading formed good-quality blastocysts, and their pregnancy outcomes were similar to those of other embryos. Most 0PN-derived embryos in the fixed-point assessment might have resulted from missed observation of PN appearance in the early-cleaved embryos. TLM or strict laboratory schedule management may reduce 0PN-derived embryos by reducing missed PN observations.
  • Kinnosuke Yahiro, Kohei Ogura, Yoshiyuki Goto, Sunao Iyoda, Tatsuya Kobayashi, Hiroki Takeuchi, Makoto Ohnishi, Joel Moss
    Scientific reports 10(1) 18943-18943 2020年11月3日  査読有り
    Shiga-toxigenic Escherichia coli (STEC) infection causes severe bloody diarrhea, renal failure, and hemolytic uremic syndrome. Recent studies showed global increases in Locus for Enterocyte Effacement (LEE)-negative STEC infection. Some LEE-negative STEC produce Subtilase cytotoxin (SubAB), which cleaves endoplasmic reticulum (ER) chaperone protein BiP, inducing ER stress and apoptotic cell death. In this study, we report that SubAB induces expression of a novel form of Lipocalin-2 (LCN2), and describe its biological activity and effects on apoptotic cell death. SubAB induced expression of a novel LCN2, which was regulated by PRKR-like endoplasmic reticulum kinase via the C/EBP homologous protein pathway. SubAB-induced novel-sized LCN2 was not secreted into the culture supernatant. Increased intracellular iron level by addition of holo-transferrin or FeCl3 suppressed SubAB-induced PARP cleavage. Normal-sized FLAG-tagged LCN2 suppressed STEC growth, but this effect was not seen in the presence of SubAB- or tunicamycin-induced unglycosylated FLAG-tagged LCN2. Our study demonstrates that SubAB-induced novel-sized LCN2 does not have anti-STEC activity, suggesting that SubAB plays a crucial role in the survival of LEE-negative STEC as well as inducing apoptosis of the host cells.
  • Baba, N., Ishikawa, H., Kobayashi, T., Matsuoka, A., Kambe, M., Shozu, M.
    Chiba Medical Journal 96E 2020年  
  • BABA Nao, ISHIKAWA Hiroshi, KOBAYASHI Tatsuya, MATSUOKA Ayumu, KAMBE Michiyo, SHOZU Makio
    Chiba Medical Journal 96E(1) 2020年  査読有り
  • 小川 美咲, 石川 博士, 小林 達也, 石井 久美子, 佐藤 明日香, 齊藤 佳子, 中村 名津子, 藤田 真紀, 高木 亜由美, 生水 真紀夫
    千葉県産科婦人科医学会雑誌 13(2) 91-91 2020年1月  査読有り
  • Akira Mitsuhashi, Yuji Habu, Tatsuya Kobayashi, Yoshimasa Kawarai, Hiroshi Ishikawa, Hirokazu Usui, Makio Shozu
    Journal of gynecologic oncology 30(6) e90 2019年11月  査読有り
    OBJECTIVE: The present study investigated long-term outcomes of medroxyprogesterone acetate (MPA) plus metformin therapy in terms of control of atypical endometrial hyperplasia (AEH) and endometrial cancer (EC), and post-treatment conception. METHODS: We retrospectively analyzed 63 patients (42 with EC; 21 with AEH) who underwent fertility-sparing management using MPA plus metformin. MPA (400 mg/day) and metformin (750-2,250 mg/day) were administered to achieve complete response (CR). Metformin was administered until conception, even after MPA discontinuation. RESULTS: Of the total patients, 48 (76%) had a body mass index (BMI) ≥25 kg/m² and 43 (68%) showed insulin resistance. Sixty-one patients (97%) achieved CR within 18 months. CR rates at 6, 8-9, and 12 months were 60%, 84%, and 90%, respectively. During a median follow-up period of 57 months (range, 13-115 months), relapse occurred in 8 of 61 patients (13.1%) who had achieved CR. Relapse-free survival (RFS) in all patients at 5 years was 84.8%. Upon univariate analysis, patients with BMI ≥25 kg/m² had significantly better prognoses than did those with BMI <25 kg/m² (odds ratio=0.19; 95% confidence interval=0.05-0.66; p=0.009). Overall pregnancy and live birth rates per patient were 61% (19/31) and 45% (14/31), respectively. CONCLUSIONS: MPA plus metformin is efficacious in terms of RFS and post treatment conception. Moreover, metformin may be more efficacious for patients with BMI ≥25 kg/m².
  • Ishikawa H, Xu L, Sone K, Kobayashi T, Wang G, Shozu M
    Reproductive sciences (Thousand Oaks, Calif.) 26(3) 428-435 2019年3月  査読有り
  • Kobayashi, T., Usui, H., Tanaka, H., Shozu, M.
    New England Journal of Medicine 379(23) 2230-2236 2018年12月  査読有り筆頭著者
  • Morimoto S, Usui H, Kobayashi T, Katou E, Goto S, Tanaka H, Shozu M
    Japanese journal of infectious diseases 71(4) 274-280 2018年7月  査読有り
  • Yoshimasa Kawarai, Hirokazu Tanaka, Tatsuya Kobayashi, Makio Shozu
    Endocrinology 159(6) 2264-2274 2018年6月1日  査読有り
    Brain damage caused by hypoxic ischemic insult during the perinatal period causes hypoxic ischemic encephalopathies (HIEs). Therapeutic hypothermia is indicated for HIE, but because the therapeutic burden is large for its limited therapeutic effectiveness, another strategy is needed. Progesterone (P4) plays a neuroprotective role through the actions of its metabolite, allopregnanolone (Allo), on P4 receptor, γ-aminobutyric acid type A receptors or both. We examined the therapeutic potential of P4 using a newborn rat model of HIE. Fetal rats were exposed to transient ischemic hypoxia by 30-minute bilateral uterine artery clamping on gestational day 18. After spontaneous birth, newborn pups were subcutaneously injected with P4 (0.10 or 0.01 mg), medroxyprogesterone acetate (MPA; 0.12 mg), or Allo (0.10 mg) through postnatal days (PDs) 1 to 9. Brain damage in the rats was assessed using the rotarod test at PD50. The HIE insult reduced the rats' ability in the rotarod task, which was completely reversed by P4 and Allo, but not by MPA. Histological examination revealed that the HIE insult decreased neuronal (the cortex and the hippocampal CA1 region) and oligodendroglial cell density (the corpus callosum) through PD0 to PD50. The axon fiber density and myelin sheath thickness in the corpus callosum were also reduced at PD50. The time-course study revealed that P4 restored oligodendroglial cells by PD5, which was followed by neuroprotective action of P4 that lasted long over the injection period. These results suggest that P4 protects the neonatal brain from HIE insult via restoration of oligodendroglial cells.
  • Guiwen Wang, Hiroshi Ishikawa, Kunizui Sone, Tatsuya Kobayashi, J. Julie Kim, Takeshi Kurita, Makio Shozu
    FERTILITY AND STERILITY 101(5) 1485-U75 2014年5月  査読有り
    Objective: To establish a novel xenograft model using a severely immunocompromised host that is more convenient for uterine leiomyoma research compared with a pre-existing model using nonobese diabetic/severe combined immunodeficient (NOD/SCID) IL-2R gamma-null mice. Design: Experimental study. Setting: University and an attached animal facility. Animal(s): NOD/SCID, SCID, BALB/c nude, and NOD/SCID IL-2R gamma-null mice. Intervention(s): Xenografts consisting of primary cultured leiomyoma and myometrial cells in the subrenal and subcutaneous (SC) spaces in ovariectomized mice, followed by sex steroids (estrogen and P) administration. Main Outcome Measure(s): Viability, volume, histology, and sex steroid receptor expression of xenografts in response to sex steroid administration, to evaluate feasibility of the model; and messenger RNA expression levels of 12 genes representative of leiomyoma in the xenografts, to characterize the model. Result(s): Leiomyoma xenografts increased in volume at the highest frequency (55.1%) in response to sex steroids in NOD/SCID mice. Xenografts reproduced the histology and maintained expression of sex steroids receptors and representative genes of the original tissues. Subrenal xenografts were significantly larger than the SC xenografts, whereas those consisting of myometrial cells never increased. Conclusion(s): The modified NOD/SCID murine subrenal leiomyoma xenograft model reproduced most characteristics of the original leiomyoma tissue. Our model provides a more convenient research tool to investigate the pathogenesis of uterine leiomyoma. (C) 2014 by American Society for Reproductive Medicine.

MISC

 53

講演・口頭発表等

 15

共同研究・競争的資金等の研究課題

 7