Live cell imaging to monitor stress-responsive signaling involved in cell reprogramming and differentiation

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K20118
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Biomedical engineering and related fields
• Research Institution: Ritsumeikan University
• Principal Investigator: Kawamura Teruhisa 立命館大学, 生命科学部, 准教授 (90393199)
• Project Period (FY): 2017-06-30 – 2019-03-31
• Keywords: 幹細胞イメージング / 蛍光共鳴エネルギー移動 / 再生医学

Outline of Final Research Achievements

While it has been of great importance to establish regenerative medicine using induced pluripotent stem (iPS) cells, we need to consider safety and effectiveness of iPS cell-based therapy for clinical application. Thus, it remains an important issue to elucidate molecular mechanisms explaining how somatic cells are reprogrammed to iPS cells. We have been investigating stress-responsive signals involved in reprogramming, and have screened, in the present study, stress-responsive kinases of which activities are altered during the reprogramming process. Our results showed that one of the mitogen-activated protein kinases, JNK is less activated after reprogramming induction, compared to non-reprogrammed mouse embryonic fibroblasts. We performed time-laps living cell imaging using the biosensor based on fluorescence resonance energy transfer, and found that reprogrammed cells are less responsive to JNK signaling after DNA damage stimuli.

Free Research Field

再生医学

Academic Significance and Societal Importance of the Research Achievements

多能性の獲得（=初期化）や未分化性の維持および細胞分化の分子機構を、ストレス応答シグナルに着目し、これを一細胞レベルで生きた状態で解析することは挑戦的であり、iPS細胞を臨床応用するうえで最大の課題である癌化回避に向けた有用かつ意義深い研究といえる。iPS細胞を用いた再生医療は、網膜で臨床試験が実施され、心不全に対する心筋シートへの応用も期待されているが、移植後の分化抵抗性細胞の検出や、移植細胞における癌化に関わるストレス応答シグナル伝達を生きた状態で経時的にモニターする評価系はいまだ確立されていない。このような背景からも、本研究の成果は再生医療の安全な実施に貢献するものと期待される。