Kyushu University Academic Staff Educational and Research Activities Database
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Kunimasa Ohta Last modified date:2023.01.04

Graduate School

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 Reseacher Profiling Tool Kyushu University Pure
Department of Stem Cell Biology .
Academic Degree
Country of degree conferring institution (Overseas)
Field of Specialization
Stem Cell Biology
ORCID(Open Researcher and Contributor ID)
Total Priod of education and research career in the foreign country
Research Interests
  • Regulation of neural stem cell niche by soluble molecules Tsukushi and Akhirin
    keyword : neural stem cell, niche, Tsukushi, Akhirin
  • Cellular transdifferentiation by ribosome
    keyword : Transdifferentiation, ribosome, stem cell
Academic Activities
1. Naofumi Ito, Kunimasa Ohta, Reprogramming of cells by lactic acid bacteria, Springer Singapore, 10.1007/978-981-10-8372-3_4, 47-61, 2018.04.
1. N. Ito, M. A. Riyadh, S. A. I. Ahmad, S. Hattori, Y. Kanemura, H. Kiyonari, T. Abe, Y. Furuta, Y. Shinmyo, N. Kaneko, Y. Hirota, G. Lupo, J. Hatakeyama, F. A. Abdulhaleem M, M. B. Anam, T. Yamaguchi, T. Takeo, H. Takebayashi, M. Takebayashi, Y. Oike, N. Nakagata, K. Shimamura, M. J. Holtzman, Y. Takahashi, F. Guillemot, K. Miyakawa, K. Sawamoto, and K. Ohta, Dysfunction of the proteoglycan Tsukushi causes hydrocephalus through altered neurogenesis in the subventricular zone, Science Translational Medicine, DOI: 10.1126/scitranslmed.aay7896, 13, 587, eaay7896, 2021.03, [URL], The lateral ventricle (LV) is flanked by the subventricular zone (SVZ), a neural stem cell (NSC) niche rich in extrinsic growth factors regulating NSC maintenance, proliferation and neuronal differentiation. Dysregulation of the SVZ niche causes LV expansion, a condition known as hydrocephalus; however, the underlying pathological mechanisms areis unclear. We show that deficiency of the proteoglycan Tsukushi (TSK) in ependymal cells at the LV surface and in the cerebrospinal fluid (CSF) results in hydrocephalus with neurodevelopmental disorder-like symptoms in mice. These symptoms are accompanied by altered differentiation and survival of the NSC lineage, disrupted ependymal structure and dysregulated Wnt signaling. Multiple TSK variants found in patients with hydrocephalus patients exhibit reduced physiological activity in mice in vivo and in vitro. Administration of wild-type TSK protein or Wnt antagonists, but not of hydrocephalus-related TSK variants, in the LV of TSK knockout mice preventeds hydrocephalus and preserveds SVZ neurogenesis. These observations reveal suggest that TSK plays a crucial role for TSK as a niche molecule modulating the fate of SVZ NSCs and point to TSK as a candidate for the diagnosis and therapy of hydrocephalus..
2. Naofumi Ito, Kaoru Katoh, Hiroko Kushige, Yutaka Saito, Terumasa Umemoto, Yu Matsuzaki, Hiroshi Kiyonari, Daiki Kobayashi, Minami Soga, Takumi Era, Norie Araki, Yasuhide Furuta, Toshio Suda, Yasuyuki Kida, Kunimasa Ohta, Ribosome Incorporation into Somatic Cells Promotes Lineage Transdifferentiation towards Multipotency, Scientific reports, 10.1038/s41598-018-20057-1, 8, 1, 2018.12, Recently, we reported that bacterial incorporation induces cellular transdifferentiation of human fibroblasts. However, the bacterium-intrinsic cellular- transdifferentiation factor remained unknown. Here, we found that cellular transdifferentiation is caused by ribosomes. Ribosomes, isolated from both prokaryotic and eukaryotic cells, induce the formation of embryoid body-like cell clusters. Numerous ribosomes are incorporated into both the cytoplasm and nucleus through trypsin-activated endocytosis, which leads to cell-cluster formation. Although ribosome-induced cell clusters (RICs) express several stemness markers and differentiate into derivatives of all three germ layers in heterogeneous cell populations, RICs fail to proliferate, alter the methylation states of pluripotent genes, or contribute to teratoma or chimera formation. However, RICs express markers of epithelial–mesenchymal transition without altering the cell cycle, despite their proliferation obstruction. These findings demonstrate that incorporation of ribosomes into host cells induces cell transdifferentiation and alters cellular plasticity..
3. Kunimasa Ohta, Rie Kawano, Naofumi Ito, Lactic Acid Bacteria Convert Human Fibroblasts to Multipotent Cells, PloS one, 10.1371/journal.pone.0051866, 7, 12, 2012.12.
1. Kunimasa Ohta, Lactic Acid Bacteria Converts Human Fibroblasts to Multipotent cells, Kumamoto - NCBS/InStem Partnership Meeting, 2019.03.
2. Kunimasa Ohta, Lactic acid bacteria convert human fibroblasts into multipotent cells, The 6th Beneficial Microbes Conference, 2017.10.
Membership in Academic Society
  • International Society for Stem Cell Research
  • The International CCN Society
  • The Japan Neuroscience Society
  • The Molecular Biology Society of Japan