Molecular and cellular mechanisms underlying intercellular transfer of double stranded RNA

• Project/Area Number: 16K18517
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Functional biochemistry
• Research Institution: Tokyo Women's Medical University
• Principal Investigator: Dejima Katsufumi 東京女子医科大学, 医学部, 助教 (60457439)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2016: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: C. elegans / RNA干渉 / systemic RNAi / 亜鉛 / 小胞輸送 / zinc transporter / RNAi / dsRNA / 亜鉛輸送体 / Systemic RNAi / 細胞・組織

Outline of Final Research Achievements

In C. elegans, dsRNA spreads throughout the whole body and causes RNA silencing in cell non-autonomous manner. This phenomenon is termed systemic RNAi. Previous genetic studies identified several genes involved in systemic RNAi. The molecular mechanisms by which systemic spread of dsRNA occurs in C. elegans appear to be conserved, at least partly, among plants, invertebrates and vertebrates. However, molecules that mediate RNA transport between cells remain largely unknown. We previously reported that mutations in rsd-3, a gene encoding conserved ENTH domain protein, is required for efficient import of silencing RNA, and the rsd-3 mutants displayed an incomplete defect in systemic RNAi. From a genetic screen for mutations able to suppress the defective RNAi phenotype of rsd-3 mutants, we found a zinc transporter gene is the causal gene of the suppression phenotype.

Academic Significance and Societal Importance of the Research Achievements

細胞間を伝播するという「可動性」と遺伝子配列に応じた作用するという「特異性」と「汎用性」から機能性RNAを使った遺伝子治療は魅力的なアプローチの一つである。最近になり一部の核酸医薬品が実用化されているが、未だに一回あたりの投与量が多く、治療費が高額になるという問題もある。このように、未だに十分な送達システムが構築されたとは言えない状況である。本研究で新たに亜鉛の膜輸送を介した小胞輸送が機能性RNAの細胞間の移動に関与することが明らかになった。この発見を創薬研究に発展させることで、近い将来核酸医薬品などの送達システムの開発に貢献することになると期待できる。

Research Products

• [Journal Article] An Aneuploidy-Free and Structurally Defined Balancer Chromosome Toolkit for Caenorhabditis elegans (2018)
  • Author(s): Dejima Katsufumi、Hori Sayaka、Iwata Satoru、Suehiro Yuji、Yoshina Sawako、Motohashi Tomoko、Mitani Shohei
  • Journal Title: Cell Reports Volume: 22 Issue: 1 Pages: 232-241
  • DOI: 10.1016/j.celrep.2017.12.024
  • Peer Reviewed / Open Access
• [Journal Article] Endomembrane-associated RSD-3 is important for RNAi induced by extracellular silencing RNA in both somatic and germ cells of Caenorhabditis elegans. (2016)
  • Author(s): Imae R, Dejima K, Kage-Nakadai E, Arai H, Mitani S.
  • Journal Title: Sci Rep. Volume: 6 Issue: 1 Pages: 28198-28198
  • DOI: 10.1038/srep28198
  • Peer Reviewed / Open Access
• [Journal Article] Chondroitin 4-O-sulfotransferase is indispensable for sulfation of chondroitin and plays an important role in maintaining normal life span and oxidative stress responses in nematodes. (2016)
  • Author(s): Izumikawa, T., Dejima, K., Watamoto, Y., Nomura, K. H., Kanai, N., Rikitake, M., Tou, M., Murata, D., Yanagita, E., Kano, A., Mitani, S., Nomura, K., and Kitagawa, H.
  • Journal Title: J. Biol. Chem. Volume: 291 Issue: 44 Pages: 23294-23304
  • DOI: 10.1074/jbc.m116.757328
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] An endosome-resident zinc transporter is involved in negative regulation of systemic dsRNA spreading in C. elegans (2019)
  • Author(s): Katsufumi Dejima, Rieko Imae, Yuji Suehiro and Shohei Mitani
  • Organizer: 22nd International C. elegans Conference
  • Int'l Joint Research
• [Presentation] Negative regulation of systemic RNAi by an endosome-resident zinc transporter in C. elegans (2019)
  • Author(s): Katsufumi Dejima, Rieko Imae, Yuji Suehiro and Shohei Mitani
  • Organizer: 2019 RNA Therapeutics: From Mechanisms to Therapy
  • Int'l Joint Research
• [Presentation] An endosome-resident zinc transporter negatively regulates systemic dsRNA spreading in C. elegans (2019)
  • Author(s): Katsufumi Dejima, Rieko Imae, Yuji Suehiro and Shohei Mitani
  • Organizer: FAOPS2019
  • Int'l Joint Research
• [Presentation] An endomembrane-resident zinc transporter negatively regulates systemic RNAi in C. elegans. (2018)
  • Author(s): Katsufumi Dejima, Rieko Imae, Yuji Suehiro and Shohei Mitani
  • Organizer: C. elegans Development, Cell Biology & Gene Expression Meeting EMBO workshop
  • Int'l Joint Research
• [Presentation] Balancer chromosome toolkit for C. elegans (2017)
  • Author(s): K. Dejima, S. Hori, S. Iwata, S. Yoshina, Y. Suehiro, T. Motohashi, S. Mitani
  • Organizer: 21st International C. elegans Conference University of California, Los Angeles
  • Int'l Joint Research
• [Presentation] Analysis of suppressor mutants that allow systemic RNAi in the absence of RSD-3 (2016)
  • Author(s): Katsufumi Dejima, Rieko Imae Yuji Suehiro and Shohei Mitani
  • Organizer: The 7th Asia-Pacific Worm meeting
  • Place of Presentation: 中国、北京
  • Year and Date: 2016-06-26
  • Int'l Joint Research
• [Presentation] Genetic engineering of chromosomal balancer toolkit for gene-clusters mediated by CRISPR/Cas9 in Caenorhabditis elegans. (2016)
  • Author(s): Iwata, S., Dejima, K., Hori, S., Yoshina, S., Suehiro, Y., Mitani, S
  • Organizer: The 7th Asia-Pacific Worm meeting
  • Place of Presentation: 中国、北京
  • Year and Date: 2016-06-26
  • Int'l Joint Research