2023 Fiscal Year Final Research Report

Innovative medicine brought about by the creation of miniature human liver using ex vivo culture through medical-engineering collaboration

Research Project

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Project/Area Number	20H03744
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 55010:General surgery and pediatric surgery-related
Research Institution	ASO CORPORATION(ASO IIZUKA HOSPITAL) (2022-2023) Kumamoto University (2020-2021)
Principal Investigator	Yamashita Yoichi 株式会社麻生(株式会社麻生飯塚病院医学研究推進本部), 外科, 部長 (00404070)
Co-Investigator(Kenkyū-buntansha)	井嶋博之九州大学, 工学研究院, 教授 (10274515) 馬場秀夫熊本大学, 大学院生命科学研究部(医), 教授 (20240905) 米満吉和九州大学, 薬学研究院, 教授 (40315065) 相島慎一九州大学, 医学研究院, 教授 (70346774)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	医工連携研究 / ミニチュアヒト肝臓 / 脱細胞鋳型 / ヒト由来機能性肝細胞・胆管細胞 / オルガノイド / 細胞鋳型肝臓 / ex vivo培養 / 機能性ゲル基材
Outline of Final Research Achievements	①Heterogenous distribution of engrafted liver tissue in miniature human liver: After endothelializing the portal vein using HUVECs, cells were seeded from the hepatic artery. This methods leaded a “sinusoidal arrangement”. However, the distribution was extremely uneven. Therefore, we investigated cell seeding conditions specifically, and we found that liver tissue engrafted more widely and uniformly with low-density multi-stage seeding of 1x105 cells/mL than with one-shot seeding of 1x107 cells/mL. Gene expression of Alb, HNF4A, CYP3A4, etc. was also improved to the level of primary rat hepatocytes. ②Reproduction of a vessel-like structure in a miniature liver: When primary human hepatocytes + HUVEC + human adipose-derived mesenchymal stem cells were seeded into a decellularized liver and subjected to the ex vivo perfusion culture for 4 days, vessel-like structures of which diameter was 15 μm was observed within the tissue.
Free Research Field	再生医療、医工連携研究
Academic Significance and Societal Importance of the Research Achievements	ミニチュアヒト肝臓の組織構築や肝特異遺伝子発現を評価しながら、医工連携により新たなex-vivo長期培養システム構築した。そのシステムにより、ミニチュアヒト肝臓内に肝特異的組織構築である類洞様構造と血管を模した管腔様構造を構築する事に成功した。これまで脱細胞鋳型肝臓を再細胞化肝臓の散見されるが、肝血流の維持や酸素供給が問題となり、長期の還流培養に関する報告はない。再細胞化後の組織構築には充分な酸素が供給された状況での長期培養による細胞間クロストークの推進が重要であり、今回我々が実現したex-vivo培養長期培養システムは脱細胞鋳型を用いた再細胞化臓器作製にブレークスルーを起こす可能性がある。