研究者業績

森 千里

モリ チサト  (Chisato Mori)

基本情報

所属
千葉大学大学院 医学研究院 環境生命医学 教授 (医学博士)
学位
博士・乙(京都大学)

J-GLOBAL ID
200901071849698152
researchmap会員ID
1000026429

外部リンク

1984年旭川医科大学卒業、同年京都大学医学部助手。カナダマニトバ大学医学部客員講師、米国国立衛生研究所客員研究員、京都大学助教授を経て2000年に千葉大学医学部教授に就任。2001年より千葉大学大学院医学研究院環境生命医学教授。2008年より千葉大学予防医学センター長兼任。専門は、環境生命医学、発生学、解剖学。著書に「鷗外と脚気」(NTT出版)等。

論文

 335
  • Yumi Kisaka, Midori Yamamoto, Kana Yanase, Kenichi Sakurai, Akifumi Eguchi, Masahiro Watanabe, Chisato Mori, Emiko Todaka
    Research in nursing & health 2025年1月8日  
    Postpartum depressive symptoms (PDS) are a common mental health condition among women after delivery. Although various causative factors have been reported, PDS remains a challenging condition to predict and prevent. The disruption of the gut microbiota due to antibiotic exposure has been reported to affect psychiatric conditions. Similarly, previous research suggests that antibiotic exposure during pregnancy could be related to PDS. Therefore, this prospective study examines the association between antibiotic exposure during pregnancy and PDS for 6 months after delivery. Data were obtained from 65,272 mothers from the Japan environment and children's study, a prospective birth cohort study. The ratios of maternal PDS at 1 and 6 months after delivery were 12.3% and 10.1%, respectively. During pregnancy, 10.7% of women took antibiotics orally. Antibiotic exposure during pregnancy was associated with an increased risk of PDS only at 6 months after delivery (OR = 1.13, 95% CI [1.00, 1.26]), adjusted for potential confounding factors. An increase in Edinburgh Postnatal Depression Scale scores in relation to antibiotic exposure during pregnancy was primarily observed via psychological distress during pregnancy. Although a causal link was not established, antibiotic exposure during pregnancy may be a contributing risk factor for PDS. Therefore, when antibiotic administration is required, clinical practitioners and perinatal care providers should consider the potential risk for PDS.
  • Masaya Koshizaka, Akifumi Eguchi, Kohki Takaguchi, Midori Yamamoto, Rieko Takatani, Aya Hisada, Akiko Kawanami, Yuki Konno, Masahiro Watanabe, Kayo Tsumura, Keiichi Shimatani, Norimichi Suzuki, Chisato Mori, Kenichi Sakurai
    BMJ open 14(12) e085682 2024年12月9日  
    PURPOSE: Epidemiological studies have reported that environmental factors from fetal period to early childhood can influence the risk of non-communicable diseases in adulthood. This concept has been termed the developmental origins of health and disease (DOHaD). The Chiba study of Mother and Child Health (C-MACH) is a DOHaD concept-based birth cohort study which started in 2014. This study aims to investigate the effects of genetic and environmental factors, particularly fetal and postnatal living environment, on children's health. We also aim to identify candidate biomarkers for their health status. Moreover, the second phase study of C-MACH which was initiated in 2021 aimed at expanding the sample size, especially for gut microbiota and epigenomic analysis; it also aimed at clarifying the impact of the coronavirus disease 2019 (COVID-19) pandemic on children's health. PARTICIPANTS: This study consists of four hospital-based cohorts. Women who were <13 weeks pregnant and their partners were enrolled in the study. All data and biological samples will be stored in the Chiba University Centre for Preventive Medical Sciences. FINDINGS TO DATE: A total of 561 women and their partners provided their consent to participate in this study. Of these women, 505 completed the questionnaire during the early gestational period. The mean age of the 505 women at enrolment was 33.0 (SD, 4.5) years. The mean prepregnancy body mass index (BMI) was 21.7 (SD, 3.6) kg/m2, with 74.5% of the women having a BMI of 18.5-24.9 kg/m2. About 5.2% of the women smoked cigarettes during the early stages of pregnancy. FUTURE PLANS: The primary study outcomes are allergies, obesity, endocrine and metabolic disorders and developmental difficulties in children. Variables related to genome, metabolome, epigenome, gut microbiota and exposome will be evaluated as health-related factors. The relationships between these outcomes and the health-related factors will be analysed.
  • Shohei Kuraoka, Masako Oda, Takashi Ohba, Hiroshi Mitsubuchi, Kimitoshi Nakamura, Takahiko Katoh, Michihiro Kamijima, Shin Yamazaki, Yukihiro Ohya, Reiko Kishi, Nobuo Yaegashi, Koichi Hashimoto, Chisato Mori, Shuichi Ito, Zentaro Yamagata, Hidekuni Inadera, Takeo Nakayama, Tomotaka Sobue, Masayuki Shima, Seiji Kageyama, Narufumi Suganuma, Shoichi Ohga, Takahiko Katoh
    Environmental Pollution 361 124801-124801 2024年11月  
  • Akifumi Eguchi, Kenichi Sakurai, Midori Yamamoto, Chisato Mori
    Ecotoxicology and environmental safety 286 117256-117256 2024年11月1日  
    The increasing exposure to environmental chemicals calls for comprehensive non-targeted analysis to detect unrecognized substances in human samples. We examined human serum samples to classify compounds as endogenous or exogenous using public databases and to explore the relationships between exposure markers and metabolic patterns. Serum samples from 84 pregnant women at 32 weeks gestation were analyzed using LC-QToFMS. Using the PubChemLite for Exposomics database, we annotated and classified 106 compounds (51 endogenous, 55 exogenous). The compound patterns were analyzed using three dimensional reduction methods: Principal Component Analysis (PCA), regularized Generalized Canonical Correlation Analysis (rGCCA), and Uniform Manifold Approximation and Projection (UMAP). OPTICS clustering applied to these methods revealed two distinct clusters, with 89 % of significant compounds overlapping between clusters. The detected exogenous compounds included dietary substances, phthalates, nitrogenous compounds, and parabens. Pathway enrichment analysis showed that chemical exposure was linked to changes in amino acid metabolism, protein and mineral transport, and energy metabolism. While we found associations between exposure and metabolite changes, we could not establish causality. Our approach of analyzing both exogenous and endogenous chemicals from the same dataset using PubChemLite database presents a new method for exposome research, despite limitations in sample size and peak annotation accuracy. These findings contribute to understanding multiple chemical exposures and their metabolic effects in human biomonitoring.
  • Masami Narita, Midori Yamamoto, Kenichi Sakurai, Chisato Mori
    Journal of epidemiology 2024年9月7日  
    BackgroundParents' educational background is presumed to influence the incidence of vaccine-preventable diseases in children through their decisions about vaccinations and other family lifestyle choices. Regarding voluntary vaccination, a household's economic situation may also be associated with non-vaccination. Therefore, this study investigated the association between parental education and vaccine-preventable diseases (varicella, mumps, influenza [flu], pertussis, measles, and rubella) in children, which currently remains elusive.MethodsWe used datasets from the Japan Environment and Children's Study, which included 104,062 fetal records; our study population comprised 80,930 children up to the age of three years. The associations between parental educational background and children's infectious diseases were examined using binomial logistic regression analysis. The mediating effects of household income, vaccination, and smoking were examined using a path analysis.ResultsFor varicella, mumps, and influenza covered by voluntary vaccination, a higher education level of the father was associated with a lower incidence of infection. The association between mothers' education and children's infection was limited. There were both income-mediated and non-income-mediated pathways between parental education and voluntary vaccination. For pertussis, measles, and rubella, which are covered by routine vaccines, there was no association between parental education and the child's infection.ConclusionAn association between parental education and childhood infections was observed. Additionally, providing financial support for vaccination and communicating the benefits of vaccination in a way that parents at all levels of education can understand will help reduce the incidence of infectious diseases among children.

MISC

 321
  • 中央公論新社 (東京); ISBN: 4 12 101638 6 2002年  
  • 有斐閣 2002年  
  • 中央公論新社 2002年  
  • MORI C, HAMAMATSU A, NAKAMURA N, TAKEICHI S, MORITA M, TANIHARA S, KAYAMA F, SHIYOMI M, YOSHIMURA J
    Anatomical Science International 77(2) 109-116 2002年  
  • Emiko Todaka, Chisato Mori
    Congenital anomalies 42(2) 87-93 2002年  
    Our recent study clearly shows that fetuses are exposed to multiple chemicals including endocrine disruptors in Japan. Although the embryo and fetus stages are the most sensitive period to chemicals in humans' life cycle, the health effects of the chemicals such as endocrine disruptors to them are largely unknown. The conventional risk assessment method cannot assess the risk to fetuses precisely. Now we need a new risk assessment, in which the target is fetuses and not the adults, in addition to the conventional risk assessment. At the same time, we also need a new strategy to practically eliminate the risk for the future generations. To make the strategy effective, we suggest a new approach to reduce the risk and avoid the possible adverse health effects, using primary, secondary and tertiary preventions as they are used in public health. We also suggest a new concept of "pre-primary prevention" to reduce the risk for fetuses. Furthermore, to make this method even more practical, we suggest a new risk communication method. In this paper, we present a framework of risk avoidance of multiple chemical exposure to fetuses.
  • SHIBAYAMA T, FUKATA H, SAKURAI K, ADACHI T, KOMIYAMA M, IGUCHI T, MORI C
    Endocrine Journal 48(6) 655-663 2001年12月  
  • T Shibayama, H Fukata, K Sakurai, T Adachi, M Komiyama, T Iguchi, C Mori
    ENDOCRINE JOURNAL 48(6) 655-663 2001年12月  
    We investigated the long-term estrogenic influence of genistein on the male reproductive system in mice. Newborn ICR male mice were treated with genistein (10, 100, or 1000 mug/mouse) for neonatal 5 days. As positive control, administration of diethylstilbestrol (0.5-50 mug/mouse) was carried out. In mice exposed to genistein,we examined weight of testes, sperm counts, sperm motility, and mRNA expression levels of estrogen receptor alpha (ER alpha) and androgen receptor (AR) at 4, 8 or 12 weeks after birth. Moreover, at 12 weeks of age, we evaluated protein level of ER alpha. In our conventional reproductive-toxicological study (weight of testes, sperm counts and sperm motility), neonatal transient exposure to genistein did not show adverse effects on the male reproductive system in 4, 8 or 12 week old mice. However, in mice treated with genistein mRNA expression levels of ER alpha and AR were reduced at 8 weeks. This reduction was recovered at 12 weeks in mice treated with a lower dose (10 mug) of genistein but not in those with higher doses (100 mug and 1000 mug). In addition, ER alpha protein levels tended to decrease in 12 weeks of adulthood. Our results exhibited that the disruption of gene expression continued for long term such as 3 months after administration of genistein, even if no effect was found at conventional reproductive-toxicological level. We have shown that neonatal administration of weak estrogenic compound (genistein) affects male reproductive organs at molecular levels in adulthood.
  • MORI Chisato, KOMIYAMA Masatoshi, TODAKA Emiko, ADACHI Tetsuya
    Proceedings of the Japan Society for Comparative Endocrinology 16 5-5 2001年12月1日  
  • 足達 哲也, 小宮山 政敏, 櫻井 健一, 高 圭範, 関 直彦, 井口 泰泉, 森 千里
    バイオイメージング 10(3) 100-101 2001年10月1日  
  • Komiyama M., Takano K., Adachi T., Seki N., Mori C.
    Congenital anomalies 41(3) 267-267 2001年9月  
  • Adachi T., Sakurai K., Shibayama T., Komiyama M., Takano K., Koh Y., Iguchi T., Mori C.
    Congenital anomalies 41(3) 261-262 2001年9月  
  • Ono Y., Adachi T., Komiyama M., Sakurai K., Koh Y., Seki N., Iguchi T., Mori C.
    Congenital anomalies 41(3) 262-262 2001年9月  
  • JC Rockett, FL Mapp, JB Garges, JC Luft, C Mori, DJ Dix
    BIOLOGY OF REPRODUCTION 65(1) 229-239 2001年7月  
    Testicular heat shock was used to characterize cellular and molecular mechanisms involved in male fertility. This model is relevant because heat shock proteins (HSPs) are required for spermatogenesis and also protect cells from environmental hazards such as heat, radiation, and chemicals. Cellular and molecular methods were used to characterize effects of testicular heat shock (43 degreesC for 20 min) at different times posttreatment. Mating studies confirmed conclusions, based on histopathology, that spermatocytes are the most susceptible cell type. Apoptosis in spermatocytes was confirmed by TUNEL, and was temporally correlated with the expression of stress-inducible Hsp70-1 and Hsp70-3 proteins in spermatocytes. To further characterize gene expression networks associated with heat shock-induced effects, we used DNA microarrays to interrogate the expression of 2208 genes and thousands more expression sequence tags expressed in mouse testis. Of these genes, 27 were up-regulated and 151 were down-regulated after heat shock. Array data were concordant with the disruption of meiotic spermatogenesis, the heat-induced expression of HSPs, and an increase in apoptotic spermatocytes. Furthermore, array data indicated increased expression of four additional non-HSP stress response genes, and eight cell-adhesion, signaling, and signal-transduction genes. Decreased expression was recorded for 10 DNA repair and recombination genes; 9 protein synthesis, folding, and targeting genes; 9 cell cycle genes; 5 apoptosis genes; and 4 glutathione metabolism genes. Thus, the array data identify numerous candidate genes for further analysis in the heat-shocked testis model, and suggest multiple possible mechanisms for heat shock-induced infertility.
  • 藤原書店 (東京); ISBN: 4 89434 219 7 2001年  
  • 森 千里
    環境ホルモン (1) 203-212 2001年  
  • 森 千里
    千葉医学雑誌 76(5) 209-218 2000年10月1日  
    近年,環境中に放出された化学物質の多くにホルモン様あるいは抗ホルモン様作用があることが見出され,化学物質の内分泌撹乱作用による生態系への悪影響が,社会問題となっている。その理由は,内分泌撹乱物質の曝露が野生動物の生殖腺や生殖腺付属器官の発生や機能分化に異常をきたし,ホルモン代謝に悪影響を及ぼしていることが判明してきたためである。諸外国より発表された論文では,ヒトにおける「精子数の減少」や「男性生殖器の発生異常の増加」などの生殖異変の原因として,内分泌撹乱物質をあげている。さらに,ヒトの疫学調査から内分泌撹乱物質の悪影響として,精巣ガン,乳ガン,子宮内膜症,女性の思春期の早期化,免疫系・神経系への影響,さらに次世代への影響が懸念されている。ただし,内分泌撹乱物質のヒトに対する影響は,現時点では明白でない。よって,本稿では,「内分泌撹乱物質とその健康影響」と題し,内分泌撹乱物質の定義や種類および生体作用の特徴,作用メカニズム,検出法等について概説し,内分泌撹乱物質のヒトヘの影響の可能性について整理する。特に,ヒトヘの影響に関しては不明な点も多いため,当方が行っている調査研究結果の一部も紹介しながら「男性生殖能の異変」に関する報告を中心に概説する。
  • N Nakamura, M Fujioka, C Mori
    TOXICOLOGY AND APPLIED PHARMACOLOGY 167(2) 100-106 2000年9月  
    Some chemicals are known to induce limb malformations in mice. The occurrence of limb abnormality induced by chemical reagents is due to changes in the programmed cell death (PCD), 5-Bromodeoxyuridine (BrdU) is known as a potent teratogen and has been reported to induce polydactyly and other limb malformations in rodents (DiPaolo, Science 145, 501-503, 1964). Here, we undertook the morphological and genetic analyses of fetuses with limb malformations in BrdU-treated mice, in order to investigate an alteration of gene expression that resembles that of mutant mice with similar limb malformations. The fetuses of the BrdU-treated mice exhibited preaxial polydactyly and preaxial triphalangism of the hindlimb at a high incidence. Our observations showed that the PCD in the preaxial necrotic zone was found to be delayed or absent on day 11 of pregnancy. Histological analyses of these fetuses showed that the preaxial apical ectodermal ridge (AER) of the hindlimb was hyperplastic and consisted of several irregular layers. In observation of the whole-mount in situ hybridization, we detected the anterior-extended overexpression of Hoxd-11 and Hoxd-13 genes in the mesenchyme cells and the overexpression of Fgf4 and Fgf8 genes in the anterior region of the AER of hindlimbs of BrdU-treated fetuses. Our study shows that the injection of BrdU changed the PCD and gene expression during limb development and induced time-specific limb malformations during fetal development. This examination of the changes of the PCD and gene expression will be useful markers for the investigation of toxicities and teratologieties of other chemicals now present in the world environment. (C) 2000 Academic Press.
  • N Yanaka, K Kobayashi, K Wakimoto, E Yamada, H Imahie, Y Imai, C Mori
    JOURNAL OF BIOLOGICAL CHEMISTRY 275(20) 14791-14794 2000年5月  
    Spermatogenesis is a developmental process that occurs in several phases and is regulated by a large number of gene products. An insertional transgenic mouse mutant (termed kisimo mouse) has been isolated that results in abnormal germ-cell development, showing: abnormal elongated spermatids in the lumina of seminiferous tubules. We cloned the disrupted locus of kisimo and identified a novel testis-specific gene, THEG, which is specifically expressed in spermatids and was disrupted in the transgenic mouse. The yeast two-hybrid screening method revealed that THEG protein strongly interacts with chaperonin containing t-complex polypeptide-le, suggesting that THEG protein functions as a regulatory factor in protein assembly. Our findings indicate that the kisimo locus is essential for the maintenance of spermiogenesis and that a gene expression disorder may be involved in male infertility.
  • JE Welch, PL Brown, DA O'Brien, PL Magyar, DO Bunch, C Mori, EM Eddy
    JOURNAL OF ANDROLOGY 21(2) 328-338 2000年3月  
    Although the process of glycolysis is highly conserved in eukaryotes, several glycolytic enzymes have unique structural or functional features in spermatogenic cells. We previously identified and characterized the mouse complementary DNA (cDNA) and a gene for 1 of these enzymes, glyceraldehyde 3-phosphate dehydrogenase-s (Gapds). This gene is expressed only in spermatids. The enzyme appears to have an essential role in energy production required for fertilization, and it is reported to be susceptible to inhibition by certain environmental chemicals. We have now cloned and sequenced the cDNA for the human homologue of glyceraldehyde 3-phosphate dehydrogenase (GAPD2) and determined the structure of the gene. The messenger RNA (mRNA) was detected in testis, but not in 15 other human tissues analyzed by Northern blot technique. The deduced GAPD2 protein contains 408 amino acids and is 68% identical with somatic cell GAPD. GAPD2 has a 72-amino acid segment at the amino terminal end that is not present in somatic cell GAPD. This segment is proline-rich but contains smaller stretches of polyproline and is 30 amino acids shorter than the comparable segment of mouse GAPDS. The structure of the human GAPD2 gene was determined by polymerase chain reaction (PGR) to identify exon-intron junctions in a genomic clone and in total genomic DNA. The locations of these junctions in the GAPD2 gene corresponded precisely to those of the 11 exon-intron junctions in the mouse Gapds gene. Immunohistochemical studies found that GAPD2 is located in the principal piece of the flagellum of human spermatozoa, as are GAPDS in mouse and rat spermatozoa. GAPD2 extracted from human spermatozoa and analyzed by Western blot technique migrated with an apparent molecular weight of similar to 56 000, although the calculated molecular weight is 44 501. The conserved nature of the mouse, rat. and human enzymes suggests that they serve similar roles in these and other mammalian species.
  • Hiroshi Naitoh, Chisato Mori, Naoki Ohyama, Hidekazu Irie, Noriko Nakamura, Yoshihiko Nishimura, Kohei Shiota
    Congenital Anomalies 40(1) 24-31 2000年3月  
    To investigate the incorporation of oligonucleotides (ODNs) into the tissues of cultured fetal mouse palates and their effects on in vitro palatogenesis, we cultured day-12.5 fetal mouse palates in a chemically defined serumless medium supplemented with either antisense or sense ODNs to epidermal growth factor receptor (EGF-r). The EGF-r ODNs were found to be incorporated into the palatal tissue and remained detectable for at least 72 hr. Immunohistochemical and immunoblot analyses revealed that the treatment with 5μM EGF-r antisense ODN suppressed the production of EGF-r protein. No pathological change was observed in the explanted palates when they were treated with 5 μM EGF-r antisense or sense ODNs, but the treatment with 10 or 20 μM ODN caused pyknotic changes in the palatal epithelium, probably due to the ODN toxicity. The present results indicate that under optimal conditions, antisense ODNs to EGF-r can be incorporated into fetal organs cultured in vitro and specifically inhibit the production of EGF-r protein. Since the suppression of the production of EGF-r protein did not prevent the palate fusion, EGF and/or EGF-r alone may not play a critical role in palatogenesis, as suggested by previous studies. The antisense ODN technique could be of potential use for analyzing the roles of specific molecules in normal and abnormal morphogenesis.
  • 産婦人科の実際 49 1045-1052 2000年  
  • SHIBAYAMA T., MORI C.
    Congenital anomalies 39(3) 192-193 1999年9月30日  
  • C Mori, JW Allen, DJ Dix, N Nakamura, M Fujioka, K Toshimori, EM Eddy
    BIOLOGY OF REPRODUCTION 61(3) 813-822 1999年9月  
    Hsp70-2 is a unique member of the mouse 70-kDa heat shock protein family that is synthesized during meiosis in spermatogenic cells. Germ cells in male mice homozygous for a targeted mutation in the Hsp70-2 gene (Hsp70-2(-/-)) arrest in development and undergo apoptosis at the end of the pachytene spermatocyte stage of meiotic prophase, However, cells with a putative acrosome were present occasionally in histological sections of the testes of juvenile and adult Hsp70-2(-/-) mice. This study verified that acrosomes were present and investigated the relationship between acrosome formation and the process of meiosis. Histochemistry with the periodic acid-Schiff procedure and immunostaining with monoclonal antibody MN7 verified that acrosomes were present in Hsp70-2(-/-) mice, and electron microscopy showed that some of these cells had condensing nuclei characteristic of step 8-9 spermatids. The frequency of acrosome-containing cells in Hsp70-2(-/-) mice was less than 0.01% of that in wild-type mice. Propidium iodide staining and cytophotometry indicated that the average DNA content of nuclei in MN7-positive cells in Hsp70-2(-/-) mice was usually about twice, or occasionally the same as, that of nuclei in round spermatids of wild-type mice. Meiotic metaphase I and II chromosome spreads were observed in spermatogenic cells from Hsp70-2(-/-) mice but at a much lower frequency than in wild-type mice. These results indicate that not all pachytene spermatocytes in Hsp70-2(-/-) mice arrest in meiosis, but they may divide once or sometimes twice and begin acrosome formation and nuclear condensation. This demonstrates that some aspects of spermatid development can occur without the completion of meiosis in mice, as has been reported recently for Drosophila.
  • M Matsui, WC Breau, S Iwasaki, S Hagiwara, Y Tamai, C Mori, ML Bloom, MB Jerry, EM Eddy, MM Taketo
    JOURNAL OF BIOCHEMISTRY 125(6) 1104-1114 1999年6月  
    Retroviral genes are not usually expressed in mouse embryonal carcinoma (EC) cells, but they are readily expressed upon differentiation of these cells. We previously reported the isolation of EC cell lines that express a neomycin resistance (neo) gene introduced by a recombinant transducing Moloney murine leukemia virus from specific integration sites, Minta, Mintb, Mintc, or Mintd, In some of these clones, the entire 5' long terminal repeat (LTR) was deleted, and the neo gene was expressed by read-through transcription from upstream cellular promoters in a "promoter-trap" fashion, One such promoter ("promoter B" at the Mintb locus) was found in a CPG island, associated with an upstream enhancer ("enhancer B"), Although enhancer B caused expression of the neo gene in the transductant EC cell line, no endogenous transcription from promoter B was detected in the parental EC or NIH3T3 cells. In contrast, we found a strong counter-flow endogenous transcription unit ("R" for reverse), which apparently interfered with transcription from promoter B, Promoter R turned out to have a bidirectional activity in transfection assays. In normal tissues, promoter R activates gene R, which encodes an 800-residue protein that is highly homologous to the rat and human heterogeneous nuclear ribonucleoprotein U (hnRNP U), Northern and in situ hybridization analyses revealed that gene R was abundantly expressed in the testis, especially in the pachytene spermatocytes and round spermatids.
  • JH Shin, C Mori, K Shiota
    TOXICOLOGY AND APPLIED PHARMACOLOGY 155(2) 139-149 1999年3月  
    The present study investigated the occurrence of apoptotic cell death in the mouse testis at various intervals following the administration of hydroxyurea (HU). The presence of apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method and by DNA fragmentation assay using ligation-mediated polymerase chain reaction, Both the incidence of apoptotic cells and the level of DNA fragmentation in the testis increased depending on the HU dose, and they were most apparent at the highest dose (400 mg/kg). The incidence of apoptotic cells in the HU-treated group increased continuously and peaked at 12 h, but then decreased gradually, reaching control levels by 48 h. After HU treatment, TUNEL-positive apoptotic cells increased in the seminiferous epithelium of the tubules, and affected cells were found synchronously in the tubules of animals treated with HU. Spermatogonia and spermatocytes were found to be affected selectively. TUNEL-positive cells were found to be stage-specific and were primarily in stage IV-VI tubules. It has been shown that in vivo HU exposure induced testicular germ cell apoptosis dose dependently in a time- and stage-specific manner, and damaged cells appeared to be eliminated by phagocytosis by neighboring cells. Apoptosis of damaged testicular germ cells is apparently a common response to various testicular toxicants therefore protecting the next generations of germ cells from the damaged cell population. (C) 1999 Academic Press.
  • K Nakamura, A Fujita, T Murata, G Watanabe, C Mori, J Fujita, N Watanabe, T Ishizaki, O Yoshida, S Narumiya
    FEBS LETTERS 445(1) 9-13 1999年2月  
    Tissue distribution and cellular localization of rhophilin, a 71 kDa Rho-binding protein, were examined in mice. Rhophilin mRNA was highly expressed in adult testis, but was absent in the testis of WIWV mice deficient in germ cells.,An anti-rhophilin antibody detected a band of an expected size in sperm extracts, which was enriched in the tail fraction. Immunofluorescence analysis revealed two lines of striated staining running in parallel in the principal piece of the sperm tail, These results suggest that rhophilin is expressed in germ cells and localized in the fibrous sheath of the sperm tail. (C) 1999 Federation of European Biochemical Societies.
  • 放射線生物研究 34(3) 273-283 1999年  
  • Minoru Matsui, Walter C. Breau, Shiho Iwasaki, Sadahiro Hagiwara, Yoshitaka Tamai, Chisato Mori, Michael L. Bloom, Mary B. Jerry, Edward M. Eddy, Makoto M. Taketo
    Journal of Biochemistry 125(6) 1104-1114 1999年  
    Retroviral genes are not usually expressed in mouse embryonal carcinoma (EC) cells, but they are readily expressed upon differentiation of these cells. We previously reported the isolation of EC cell lines that express a neomycin resistance (neo) gene introduced by a recombinant transducing Moloney murine leukemia virus from specific integration sites, Minta, Mintb, Mintc, or Mintd. In some of these clones, the entire 5' long terminal repeat (LTR) was deleted, and the neo gene was expressed by read-through transcription from upstream cellular promoters in a 'promoter-trap' fashion. One such promoter ('promoter B' at the Mintb locus) was found in a CpG island, associated with an upstream enhancer ('enhancer B'). Although enhancer B caused expression of the neo gene in the transductant EC cell line, no endogenous transcription from promoter B was detected in the parental EC or NIH3T3 cells. In contrast, we found a strong counter-flow endogenous transcription unit ('R' for reverse), which apparently interfered with transcription from promoter B. Promoter R turned out to have a bidirectional activity in transfection assays. In normal tissues, promoter R activates gene R, which encodes an 800-residue protein that is highly homologous to the rat and human heterogeneous nuclear ribonucleoprotein U (hnRNP U). Northern and in situ hybridization analyses revealed that gene R was abundantly expressed in the testis, especially in the pachytene spermatocytes and round spermatids.
  • Chisato Mori, James W. Allen, David J. Dix, Noriko Nakamura, Makio Fujioka, Kiyotaka Toshimori, Edward M. Eddy
    Biology of Reproduction 61(3) 813-822 1999年  
    Hsp70-2 is a unique member of the mouse 70-kDa heat shock protein family that is synthesized during meiosis in spermatogenic cells. Germ cells in male mice homozygous for a targeted mutation in the Hsp70-2 gene (Hsp70-2(-/-)) arrest in development and undergo apoptosis at the end of the pachytene spermatocyte stage of meiotic prophase. However, cells with a putative acrosome were present occasionally in histological sections of the testes of juvenile and adult Hsp70-2(-/-) mice. This study verified that acrosomes were present and investigated the relationship between acrosome formation and the process of meiosis. Histochemistry with the periodic acid-Schiff procedure and immunostaining with monoclonal antibody MN7 verified that acrosomes were present in Hsp70-2(-/-) mice, and electron microscopy showed that some of these cells had condensing nuclei characteristic of step 8-9 spermatids. The frequency of acrosome-containing cells in Hsp70-2(-/-) mice was less than 0.01% of that in wild-type mice. Propidium iodide staining and cytophotometry indicated that the average DNA content of nuclei in MN7-positive cells in Hsp70-2(-/-) mice was usually about twice, or occasionally the same as, that of nuclei in round spermatids of wild-type mice. Meiotic metaphase I and II chromosome spreads were observed in spermatogenic cells from Hsp70-2(-/-) mice but at a much lower frequency than in wild-type mice. These results indicate that not all pachytene spermatocytes in Hsp70-2(-/-) mice arrest in meiosis, but they may divide once or sometimes twice and begin acrosome formation and nuclear condensation. This demonstrates that some aspects of spermatid development can occur without the completion of meiosis in mice, as has been reported recently for Drosophila.
  • 森 千里
    関西自然保護機構会報 20(2) 91-94 1998年12月  
  • C Mori, N Nakamura, JE Welch, H Gotoh, EH Goulding, M Fujioka, EM Eddy
    MOLECULAR REPRODUCTION AND DEVELOPMENT 49(4) 374-385 1998年4月  
    Unique type 1 hexokinase (HK1) mRNAs are present in mouse spermatogenic cells (mHk1-s). They encode a spermatogenic cell-specific sequence region (SSR) but not the porin-binding domain (PBD) necessary for HK1 binding to porin on the outer mitochondrial membrane. This study determined the origin of the multiple Hk1-s transcripts in mouse spermatogenic cells and verified that they are translated in mouse spermatogenic cells. It also showed that a single mHk1 gene encodes the mHk1 transcripts of somatic cells and the mHk1-sa and mHk1-sb transcripts of spermatogenic cells, that alternative exons are used during mHk1 gene expression in mouse spermatogenic cells, and that mHK1-S is translated in mouse spermatogenic cells and is localized mainly with the fibrous sheath in the tail region, not with the mitochondria in the midpiece of mouse sperm. (C) 1998 Wiley-Liss, Inc.
  • S Nakagawa, N Nakamura, M Fujioka, C Mori
    TOXICOLOGY AND APPLIED PHARMACOLOGY 147(2) 204-213 1997年12月  
    Spermatogenic cell degeneration in the mature mammalian testis occurs both spontaneously during normal spermatogenesis and in response to cytotoxic agents. Mitomycin C (MC) is an antibiotic that affects DNA synthesis. In the present study, we examined the induction of mouse spermatogenic cell apoptosis by MC, using TdT-mediated dUTP-biotin nick end labeling (TUNEL) to detect high levels of DNA fragmentation in situ, transmission electron microscopy (TEM) to observe nuclear chromatin condensation, and molecular methods to detect DNA ladders. This study shows that in the testis of MC-treated mice: (i) apoptotic cell death with fragmentation of nuclear DNA is induced by MC dose-dependently, (ii) apoptotic cell death is most commonly found in the spermatogonia and less frequently in spermatocytes, and (iii) apoptotic cell death induced by MC is not specific for the seminiferous stage of the tubules. The present study suggests that the spermatogenic cell apoptosis induced by MC might be involved in its testicular toxicity. (C) 1997 Academic Press.
  • N Nakamura, H Irie, C Mori
    MOLECULAR BIOLOGY OF THE CELL 8 1294-1294 1997年11月  
  • C Mori, N Nakamura, JE Welch, H Gotoh, EH Goulding, M Fujioka, EM Eddy
    MOLECULAR BIOLOGY OF THE CELL 8 1890-1890 1997年11月  
  • JU Lee, R Hosotani, M Wada, R Doi, T Kosiba, K Fujimoto, Y Miyamoto, C Mori, N Nakamura, K Shiota, M Imamura
    ANTICANCER RESEARCH 17(5A) 3445-3450 1997年9月  
    Cisplatin and VP-16 were used to study the induction of apoptosis in Panc-1 cells. Cisplatin and VP-16 inhibited the growth of Panc-1 cells. After 2 hours exposure to cisplatin or VP-16, attached and detached cells were subjected to TUNEL staining to calculate the ratio of apoptosis. In detached cells TUNEL positive ratios increased in a time-and dose-dependent manner In Western blotting, Bm expression was obviously upregulated but Bcl-2 remained almost constant. The results suggested that in Panc-1 cells cisplatin and VP-16 induced apoptotic cell death which was mediated through the interaction of Bax expression in the presence of mutated p53.
  • Y Nishiyama, T Tanaka, H Naitoh, C Mori, M Fukumoto, H Hiai, S Toyokuni
    JAPANESE JOURNAL OF CANCER RESEARCH 88(2) 120-128 1997年2月  
    An iron chelate, ferric nitrilotriacetate (Fe-NTA), induces renal proximal tubular necrosis, a consequence of free radical-associated damage, that ultimately leads to a polycystic change of the renal cortex and a high incidence of renal cell carcinoma (RCC) in rodents. The differential display technique was used to search for inducible genes in the kidney of male Wistar rats treated with Fe-NTA and in the induced RCCs. Six fragments were selected that showed specific quantitative changes in mRNA. Two of them exhibited similar patterns in northern blots as well. One fragment showed a high homology (89%) to murine integrin-associated protein (IAP; CD47). We thus cloned rat IAP cDNA including the entire coding region for use in further analysis. Rat IAP cDNA showed a 21-amino-acid deletion that was also observed in human, but not in mouse. Northern blots revealed that IAP was consistently overexpressed in non-tumorous parts of the kidney (2.4-fold increase, n = 9, P&lt;0.0001) as compared with matched controls 1 to 2 years after Fe-NTA treatment. IAP overexpression of more than 2.9-fold was found in 25% (2/8) of RCCs studied, and was limited to cases of a high histological grade and lung metastasis. Unexpectedly, IAP expression was higher in the non-tumorous part of the kidney after Fe-NTA treatment (2.8-fold) than in RCC (1.5-fold) in each case (n = 4, P &lt; 0.05). Abundant expression of IAP mRNA in the renal tubular epithelium after Fe-NTA treatment and RCC cells was observed by in situ hybridization. The results suggest that IAP overexpression may be associated with Fe-NTA-induced renal cortical tubular damage and regeneration that lead to a polycystic state, and with tumor progression and metastasis of the induced RCCs.
  • R Doi, M Wada, R Hosotani, JU Lee, T Koshiba, K Fujimoto, C Mori, N Nakamura, K Shiota, M Imamura
    PANCREAS 14(1) 39-46 1997年1月  
    It has been recognized in mammals that after pancreatic duct obstruction, acinar cells progressively disappear and pancreatic islets are preserved. Previous studies by electron microscopy have suggested the involvement of apoptosis in acinar cell deletion. In the present study, we employed molecular biological methods and investigated whether acinar cell deletion is due to apoptosis. In male Sprague-Dawley rats, pancreatic duct Ligation was performed through a left paramedian incision. Pancreatic tissue was studied at each of the following intervals after ligation: 3, 6, 12, 18, and 24 h and 2, 3, 5, and 7 days. DNA fragmentation was determined by in situ labeling of DNA strand breaks on tissue sections [fluorescein-labeled terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method (TUNEL)] and by electrophoretic detection of the fragments of extracted DNA. Tissue sections were also examined by hematoxylin/eosin staining and immunohistochemical staining of insulin. Pancreatic duct ligation induced acinar cell deletion by day 5. Pancreatic tissue from control rats demonstrated no TUNEL-positive nuclei. In contrast, acinar cells from rats 12 h to 5 days after duct ligation showed TUNEL-positive nuclei. The number of TUNEL-positive nuclei was maximum 2 days after duct ligation. Electrophoresis showed DNA fragmentation after duct ligation. Control rats showed a genomic DNA pattern. Islets were preserved throughout the experimental period in duct-ligated rats and control rats. The results suggest that apoptosis may be the dominant form of acinar cell death in the rat pancreatic duct ligation model.
  • C Mori, N Nakamura, DJ Dix, M Fujioka, S Nakagawa, K Shiota, EM Eddy
    DEVELOPMENTAL DYNAMICS 208(1) 125-136 1997年1月  
    The present study examined the occurrence of apoptotic cell death in the testis of wild-type mice from postnatal days 3 to 28 and in juvenile Hsp70-2 knockout mice. Adult Hsp70-2 knockout males are infertile and lack spermatids and spermatozoa (Dir et al. [1996a] Proc. Natl. Acad. Sci. U.S.A. 93:3264-3268). To identify the cell types undergoing apoptosis, we also examined the relationship between the occurrence of apoptotic cell death and the expression pattern of the Hsp70-2 gene product (heat-shock protein 70-2 [Hsp70-2]; marker for spermatocytes and spermatids), germ cell nuclear antigen 1 (GCNA1; marker for spermatogonia and spermatocytes), and vimentin (marker for Sertoli cells). This study shows that during postnatal development of the wildtype mouse testis (1) the percentage of apoptotic cell death detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method is higher in mice from days 8 to 22 than in younger or older mice, (2) the majority of apoptotic cells are spermatogonia and less frequently are spermatocytes, and (3) the degenerative cell death of spermatogonia and primary spermatocytes involves apoptosis with fragmentation of DNA. The analysis of apoptotic cell death in the testes of juvenile Hsp70-2 knockout mice showed an additional increased level of apoptosis at day 17, during the first wave of spermatogenesis, in pachytene spermatocytes. (C) 1997 Wiley-Liss, Inc.
  • C Mori, N Nakamura, JE Welch, K Shiota, EM Eddy
    MOLECULAR REPRODUCTION AND DEVELOPMENT 44(1) 14-22 1996年5月  
    Several enzymes in the glycolytic pathway are reported to have spermatogenic cell-specific isozymes. We reported recently the cloning of cDNAs representing three unique type 1 hexokinase mRNAs (mHk1-sa, mHk1-sb, and mHk1-sc) present only in mouse spermatogenic cells and the patterns of expression of these mRNAs (Mori et al., 1993: Biol Reprod 49:191-203). The mRNAs contain a spermatogenic cell-specific sequence, but lack the sequence for the porin-binding domain that somatic cell hexokinases use to bind to a pore-forming protein in the outer mitochondrial membrane. We now report the cloning of cDNAs representing three unique human type 1 hexokinase mRNAs (hHK1-ta, hHK1-tb, and hHK1-tc) expressed in testis, but not detected by Northern analysis in other human tissues. These mRNAs also contain a testis-specific sequence not present in somatic cell type 1 hexokinase, but lack the sequence for the porin-binding domain. The hHK1-tb and hHK1-tc mRNAs each contain an additional unique sequence. The testis-specific sequence of the human mRNAs is similar to the spermatogenic cell-specific sequence of the mouse mRNAs. Furthermore, Northern analysis of RNA from mouse, hamster, guinea pig, rabbit, ram, human, and rat demonstrated expression of type 1 hexokinase mRNAs lacking the porin-binding domain in the testes of these mammals. These results suggest that hexokinase may have unique structural or functional features in spermatogenic cells and support a model proposed by others for hexokinase gene evolution in mammals. (C) 1996 Wiley-Liss, Inc.
  • DJ Dix, JW Allen, BW Collins, C Mori, N Nakamura, P PoormanAllen, EH Goulding, EM Eddy
    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 93(8) 3264-3268 1996年4月  
    In addition to the five 70-kDa heat shock proteins (HSP70) common to germ cells and somatic tissues of mammals, spermatogenic cells synthesize HSP70-2 during meiosis, To determine if this unique stress protein has a critical role in meiosis, we used gene-targeting techniques to disrupt Hsp70-2 in mice. Male mice homozygous for the mutant allele (Hsp70-2(-/-)) did not synthesize HSP70-2, lacked postmeiotic spermatids and mature sperm, and were infertile, However, neither meiosis nor fertility was affected in female Hsp70-2(-/-) mice, We previously found that HSP70-2 is associated with synaptonemal complexes in the nucleus of meiotic spermatocytes from mice and hamsters. While synaptonemal complexes assembled in Hsp70-2(-/-) spermatocytes, structural abnormalities became apparent in these cells by late prophase, and development rarely progressed to the meiotic divisions, Furthermore, analysis of nuclei and genomic DNA indicated that the failure of meiosis in Hsp70-2(-/-) mice was coincident with a dramatic increase in spermatocyte apoptosis. These results suggest that HSP70-2 participates in synaptonemal complex function during meiosis in male germ cells and is linked to mechanisms that inhibit apoptosis.

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