Establishment and analysis of NMNAT1-LCA pathological model using human retinal organoids

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K18376
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56060:Ophthalmology-related
• Research Institution: The University of Tokyo
• Principal Investigator: Kuribayashi Hiroshi 東京大学, 医学部附属病院, 特任研究員 (00734211)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 網膜 / 遺伝性網膜変性疾患 / NMNAT1 / NAD

Outline of Final Research Achievements

Leber congenital amaurosis (LCA) is an inherited retinal degeneration leading to sever vision loss or blindness at early ages of life. NMNAT1 encoding the nuclear NAD synthetase is one of the causative genes of LCA. However the molecular mechanisms by which its mutations cause the degeneration are unclear. In this study, the function of NMNAT1 during retinal development was evaluated by comparing normal- and NMNAT1 knockout (KO)-human iPS cells derived retinal organoids. In this study, morphological observations and molecular biological analysis showed that NMNAT1 is essential for the expansion and formation of retina-like structures in retinal organoids. Dysfunction of the NMNAT1-NAD-PARP cascade was also confirmed in NMNAT1KO-retinal organoids. These phenotypic abnormalities showed recovery with the addition of NAD and/or NMN. Thus, this study suggested that NMNAT1 has important roles for retinal development.

Free Research Field

眼科学

Academic Significance and Societal Importance of the Research Achievements

LCAは小児の遺伝性網膜変性疾患であり、重篤な視力障害をもたらす。NMNAT1を原因とするLCAマウスモデルやマウス網膜を用いた分子生物学的解析は行われてきたが、NMNAT1変異から網膜変性に至るメカニズムの解析は不十分である。また、ヒト網膜モデルを用いた研究はこれまでになかった。本研究では、過去に樹立したNMNAT1KOヒトiPS細胞由来・網膜オルガノイドを用いて、初めてヒト網膜モデルにおけるNMNAT1の役割を明らかにした。本研究は、NMNAT1変異から網膜変性に至る病態解明に繋がる知見を与えるものであると考える。