Establishment of a cytotoxicity evaluation system for pigment cell-specific vitiligo-inducing substances and elucidation of the mechanism of damage

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K10248
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Dermatology
• Research Institution: Gifu Pharmaceutical University
• Principal Investigator: Inoue Shintaro 岐阜薬科大学, 薬学部, 特任教授 (00793853)
• Co-Investigator(Kenkyū-buntansha): 水谷 有紀子 岐阜薬科大学, 薬学部, 特任准教授 (30396296) ; 石塚 麻子 岐阜薬科大学, 薬学部, 研究補佐員 (50727203)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: ロドデノール / メラノーマ / 化学白斑 / 酸化ストレス / NRF2 / GPNMB

Outline of Final Research Achievements

NRF2 system disturbs the reproducible evaluation of rhododendrol (RD)-induced melanocyte cytotoxicity. So, we clarified whether human melanoma cells carrying NRF2-KO gene are available for evaluation of vitiligo risk compounds. We obtained two NRF2-KO clones with different deletion mutations were established, however, the cytotoxicity of risk compounds in both NRF2-KO cells was unexpectedly comparable with that of NRF2(+) clones.
Knocked down of GPNMB in NRF2-KO cells, which has been shown to disappeared in vitiligo epidermis by our study, showed an increased RD cytotoxicity, but it was rescued by the addition of recombinant GPNMB. These findings indicated that NRF2-KO melanoma cells were unavailable for evaluation of vitiligo risk compounds due to the compensatory action of anti-oxidative GPNMB with the NRF2-independent manner. GPNMB might be involved in cellular anti-oxidative activity in normal and oxidative stress-induced disease cells.

Free Research Field

皮膚科学

Academic Significance and Societal Importance of the Research Achievements

ロドデノール(RD)は尋常性白斑類似の色素脱失症を誘発する。正常メラノサイトでは、再現良いRD障害性リスク評価がNRF2系により妨げられたため、NRF2欠損メラノーマ株作出による高再現性評価系の確立、および酸化ストレス抵抗性メカニズム解明による診断・予防・治療への応用を目指した。本研究で、酸化ストレス誘導細胞障害性に対するGPNMBのNRF2非依存的抵抗性を明らかにした学術的意義は高い。我々は、尋常性白斑病変部の表皮GPNMB発現の消失と、IFNγ/IL-17による発現抑制を見い出しており（Biswas et al., 2020）、白斑発症や維持におけるGPNMB関与解明の端緒となる。