In vitro bile acid-dependent hepatocyte toxicity assay system using human induced pluripotent stem cell-derived hepatocytes

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K15527
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Medical pharmacy
• Research Institution: Nagoya City University (2018); Aichi Gakuin University (2017)
• Principal Investigator: Sakai Yoko 名古屋市立大学, 大学院薬学研究科, 助教 (50723079)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 胆汁酸 / 胆汁鬱滞肝障害 / ヒトiPS細胞 / MRP2/3/4 / サンドイッチ培養 / 毛細胆管

Outline of Final Research Achievements

We investigated whether sandwich-cultured human induced pluripotent stem cell (iPS cell)-derived hepatocytes (SCHiHs) are suitable for evaluating cholestatic hepatotoxicity. Fluorescent N-(24-[7-(4-N,N-dimethylaminosulfonyl-2,1,3-benzoxadiazole)]amino-3α,7α,12α-trihydroxy-27-nor-5β-cholestan-26-oyl)-2'-aminoethanesulfonate (tauro-nor-THCA-24-DBD) and CDF (substrate of BSEP or MRP2) were accumulated in bile canaliculi, which supports the presence of functional bile canaliculi lumen. MRP2 was highly expressed, whereas BSEP was hardly detectable in Western blot analysis. MRP3/4 mRNA levels were maintained. Of the 22 compounds known to cause DILI with BAs, 7 showed significant cytotoxicity. Most higher risk drugs were detected using the current SCHiH system. However, a shortcoming was the considerably low protein expression level of BSEP, which led to the non-detection of some relevant drugs whose risks should be detected in primary human hepatocytes.

Free Research Field

臨床薬学

Academic Significance and Societal Importance of the Research Achievements

肝細胞毒性評価系モデルの構築に対する報告は、国内外問わず、少ないと思われる。また、今回、開発したサンドイッチ培養ヒトiPS細胞由来肝細胞（SCHiHs）を用いた薬剤性胆汁うっ滞型肝毒性評価系は、ヒトiPS 細胞由来であるため、大量生産可能かつ個々の遺伝的背景を反映させた系の構築に繋がる特色がある。また、動物を使用することなく、安全性、毒性評価を行う方法を見出すことは、非臨床試験における肝毒性評価系の一つとして、今後の世論の動向とマッチしており、動物代替法および安全性の高い医薬品の開発に繋がるため、有意義なモデル系だと思われた。