Molecular mechanism of hypoxia-induced modification of cytokine cascade in periodontal ligament cells

• Project/Area Number: 18K09846
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57070:Developmental dentistry-related
• Research Institution: Nihon University
• Principal Investigator: SHIRAKAWA Tetsuo 日本大学, 歯学部, 教授 (00187527)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 歯根膜細胞 / 低酸素暴露 / DNAメチル化 / DNA脱メチル化 / ヒストンメチル化 / サイトカイン / ビーズアレイ / CpG / 歯根膜細胞株 / mRNA発現 / 脱メチル化 / HIF-1α / angiogenin / VEGF / C/EBPβ / RANKL / 不死化ヒト歯根膜細胞 / エピジェネティクス / サイトカインカスケード

Outline of Final Research Achievements

Immortalized PDL cells derived from human deciduous teeth (SH9 cells) were cultured at 37℃ in 5% CO2/95% air (normoxic condition) or in 5% CO2/<1% O2 or in 5% CO2/5% O2 (hypoxic conditions) for 12h or 24h. After an exposure to one of these environments, genomic DNA was extracted and DNA methylation analysis was performed using Infinium MethylationEPIC BeadChip (Illumina Inc.).
Among genes in which DNA methylation status was altered under the hypoxic conditions, SMYD5 and SMYD3 mRNA expression was reduced (P< 0.01) after 24h exposure to the <1% O2 environment. This finding indicates that, in a case where the activity of SMYDs as a lysine methyltransferase is reduced under hypoxia, methylation status of lysine residues within histones may be down-regulated, and as a result, chromatin structure may change extensively.

Academic Significance and Societal Importance of the Research Achievements

歯根膜は歯槽骨内で歯を保持するとともに歯根周囲のセメント質や骨の代謝にも重要な役割を果たしている。歯根膜細胞が失活すると歯根の不可逆的な吸収が進行し歯を失う原因となる。怪我などで歯根膜細胞が低酸素環境に暴露された場合に、DNAを含む核内クロマチン構造にどのような変化が生じるかについて十分には分かっていない。本研究では、低酸素暴露された歯根膜細胞で、SMYD5およびSMYD3の遺伝子発現が有意に減少することを見いだした。これらのタンパクはクロマチンを構成するヒストンのメチル化に関わっていることから、低酸素暴露がクロマチンの構造変化を介して遺伝子発現の広範な変化をもたらす可能性が示された。

Research Products

• [Journal Article] Effect of hypoxia on the expression of CCAAT/enhancer-binding protein β and receptor activator of nuclear factor kappa-B ligand in periodontal ligament cells (2018)
  • Author(s): Hisanori Ito, Takashi Kifune, Misa Ishiyama, Satoko Iwasa, Hiroki Takei, Tomokazu Hasegawa, Masatake Asano, and Tetsuo Shirakawa
  • Journal Title: Journal of Oral Science Volume: 60 Issue: 4 Pages: 544-551
  • DOI: 10.2334/josnusd.17-0436
  • NAID: 130007553050
  • ISSN: 1343-4934, 1880-4926
  • Peer Reviewed / Open Access
• [Journal Article] Hypoxia-induced upregulation of angiogenic factors in immortalized human periodontal ligament fibroblasts (2018)
  • Author(s): Takashi Kifune, Hisanori Ito, Misa Ishiyama, Satoko Iwasa, Hiroki Takei, Tomokazu Hasegawa, Masatake Asano, and Tetsuo Shirakawa
  • Journal Title: Journal of Oral Science Volume: 60 Issue: 4 Pages: 519-525
  • DOI: 10.2334/josnusd.17-0441
  • NAID: 130007553036
  • ISSN: 1343-4934, 1880-4926
  • Peer Reviewed / Open Access
• [Presentation] Hypoxia-induced expression of CCAAT/enhancer-binding protein β and receptor activator of nuclear factor kappa-B ligand in periodontal ligament cells (2019)
  • Author(s): Ito Hisanori、Kifune Takashi、Ishiyama Misa、Iwasa Satoko、Takei Hiroki、Hasegawa Tomokazu、Asano Masatake、Shirakawa Tetsuo
  • Organizer: 27th IAPD Congress
  • Int'l Joint Research
• [Presentation] Upregulation of angiogenin and VEGF productions in immortalized human periodontal ligament fibroblasts exposed to hypoxia (2019)
  • Author(s): Shirakawa Tetsuo、Kifune Takashi、Ito Hisanori、Ishiyama Misa、Iwasa Satoko、Takei Hiroki、Hasegawa Tomokazu、Asano Masatake
  • Organizer: 27th IAPD Congress
  • Int'l Joint Research