Noriko Osumi

Publications (138) View all

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  Available from: Noriko Osumi

  Chapter: NeurogenesisBookChapter2011: Impaired neurogenesis as a risk for mental dieseases

  N Osumi, N Guo
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  ABSTRACT: Neurogenesis is a biological process with multiple steps, and it is critical in brain development and maintenance. The initial step in neurogenesis is the division of neural stem cells to renew themselves, simultaneously producing neuronally committed cells. The integrity of neurogenesis is vulnerable to both genetic and environmental factors. Etiological data imply that impairment in neurogenesis, which is possibly caused by genetic factors as well as by infection, stress, and low nutrition, may underlie the onset of mental diseases. In support of this, an intrigu-ing association of abnormal hippocampal neurogenesis and deficits in prepulse inhibition (PPI), one of the compelling endophenotypes (biological markers) of mental disorders including schizophrenia, has been reported in various animal models. If impaired neurogenesis is truly a susceptibility factor for mental diseases, the restoration and improvement of neurogenesis may be beneficial. Here, we introduce an approach using fatty acids to restore neurogenesis. In the future, we hope that noninvasive imaging of neurogenesis will provide biological evidence for diagnosis, treatment, and prognosis of mental diseases.
  03/2013: pages 111-132;
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  Available from: Noriko Osumi

  Article: The effects of Fabp7 and Fabp5 on postnatal hippocampal neurogenesis in the mouse.

  Miho Matsumata, Nobuyuki Sakayori, Motoko Maekawa, Yuji Owada, Takeo Yoshikawa, Noriko Osumi
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  ABSTRACT: New neurons are continually produced after birth from neural stem/progenitor cells (NSCs/NPCs) in the hippocampal dentate gyrus (DG). Recent studies have reported that fatty acid binding protein 7 (Fabp7/brain lipid binding protein (BLBP)) is required for the maintenance of embryonic NSCs/NPCs and have identified an association between the Fabp7 gene and behavioral paradigms that correlate with hippocampal functions. However, the specific roles of Fabps in postnatal neurogenesis remain unknown. Herein, we demonstrate the effects of Fabp7, and another Fabp, Fabp5, on postnatal neurogenesis. Fabp7 and Fabp5 were detected in the subgranular zone (SGZ) of the DG, and Fabp7+ cells were less differentiated than Fabp5+ cells. We analyzed the differentiation state of NSCs/NPCs in the SGZ of 4-week-old (4w) Fabp7 knockout (7KO), Fabp5 KO (5KO), and Fabp7/Fabp5 double KO (7/5KO) mice and found that the number of NSCs/NPCs was dramatically reduced compared with wild-type mice. Although the uptake of BrdU 1 day after injection was decreased in all KO mice, the survival of BrdU+ cells 1 month after injection was increased in the 7/5KO mice compared to other three genotypes. We also observed an enhancement of neuronal differentiation in all Fabp KO mice. In addition, the proliferation and survival of NSCs/NPCs differed along the anterior-posterior axis (A-P axis). A greater number of newborn cells in the posterior region became extinct, but this tendency was not apparent in the Fabps KO mice. These data suggest that Fabp7 and Fabp5 have differential roles for proliferation and survival of the NSCs/NPCs during postnatal DG neurogenesis.
  Stem Cells 05/2012; 30(7):1532-43. · 7.78 Impact Factor
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  Available from: Yuji Tsunekawa

  Article: Cyclin D2 in the basal process of neural progenitors is linked to non-equivalent cell fates.

  Yuji Tsunekawa, Joanne M Britto, Masanori Takahashi, Franck Polleux, Seong-Seng Tan, Noriko Osumi
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  ABSTRACT: Asymmetric cell division plays an indispensable role during corticogenesis for producing new neurons while maintaining a self-renewing pool of apical progenitors. The cellular and molecular determinants favouring asymmetric division are not completely understood. Here, we identify a novel mechanism for generating cellular asymmetry through the active transportation and local translation of Cyclin D2 mRNA in the basal process. This process is regulated by a unique cis-regulatory sequence found in the 3' untranslated region (3'UTR) of the mRNA. Unequal inheritance of Cyclin D2 protein to the basally positioned daughter cell with the basal process confers renewal of the apical progenitor after asymmetric division. Conversely, depletion of Cyclin D2 in the apically positioned daughter cell results in terminal neuronal differentiation. We demonstrate that Cyclin D2 is also expressed in the developing human cortex within similar domains, thus indicating that its role as a fate determinant is ancient and conserved.
  The EMBO Journal 03/2012; 31(8):1879-92. · 9.20 Impact Factor
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  Available from: Noriko Osumi

  Article: Distinctive effects of arachidonic acid and docosahexaenoic acid on neural stem /progenitor cells.

  Nobuyuki Sakayori, Motoko Maekawa, Keiko Numayama-Tsuruta, Takashi Katura, Takahiro Moriya, Noriko Osumi
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  ABSTRACT: Arachidonic acid (ARA) and docosahexaenoic acid (DHA), which are the dominant polyunsaturated fatty acids in the brain, have crucial roles in brain development and function. Recent studies have shown that ARA and DHA promote postnatal neurogenesis. However, the direct effects of ARA on neural stem/progenitor cells (NSPCs) and the effects of ARA and DHA on NSPCs at the neurogenic and subsequent gliogenic stages are still unknown. Here, we analyzed the effects of ARA and DHA on neurogenesis, specifically maintenance and differentiation, using neurosphere assays. We confirmed that primary neurospheres are neurogenic NSPCs and that tertiary neurospheres are gliogenic NSPCs. Regarding the effects of ARA and DHA on neurogenic NSPCs, ARA and DHA increased the number of neurospheres, whereas neither ARA nor DHA had a detectable effect on NSPCs in the differentiation condition. In gliogenic NSPCs, DHA increased the number of neurospheres, whereas ARA had no such effect. In contrast, ARA increased the number of astrocytes, whereas DHA increased the number of neurons in the differentiation condition. These results suggest that ARA promotes the maintenance of neurogenic NSPCs and might induce the glial differentiation of gliogenic NSPCs and that DHA promotes the maintenance of both neurogenic and gliogenic NSPCs and might lead to the neuronal differentiation of gliogenic NSPCs.
  Genes to Cells 07/2011; 16(7):778-90. · 2.68 Impact Factor
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  Available from: Noriko Osumi

  Article: Life science must go on: standing up after the 311 disaster.

  Noriko Osumi
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  ABSTRACT: Just 1 month has passed since the biggest earthquake ever recorded in Japan occurred in the Tohoku-Kanto area. The earthquake was followed soon afterwards by an unexpected huge tsunami that destroyed many villages and towns near the coast. Perhaps even more seriously, nuclear power plants in Fukushima were damaged, resulting in electricity interruptions and radioactive contamination. It is sad that nearly thirty thousand people died or are still missing as a result of this disaster. I wish to express my deepest sympathy to all the victims and for those that are still being affected by what happened. The 311 earthquake and the ensuing problems have shaken us to the bottom of our hearts, not only physically but also mentally. As one of the persons present in the area at the time of the earthquake, I would like to report how I experienced the 311 disaster in our laboratory in Tohoku University and how this experience has changed my outlook on many things.
  Genes to Cells 07/2011; 16(7):741-4. · 2.68 Impact Factor