2021 Fiscal Year Research-status Report
iPS細胞由来網膜移植にて視機能再建のための変性網膜の視覚回路の解析と最適化
| Project/Area Number |
20K18403
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| Research Institution | Osaka University |
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Principal Investigator |
Tu HungYa 大阪大学, 蛋白質研究所, 助教 (10780835)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | retinal degeneration / horizontal cell / organoid transplantation / multielectrode array |
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| Outline of Annual Research Achievements |
Following the establishment of mouse model for conditional ablation of horizontal cells in photoreceptor degeneration, mouse retinal organoid transplantation and functional assay have been conducted to probe the role of remaining horizontal cells in the host-graft reconstruction.
De novo synapses between host bipolar cells and graft photoreceptors were observed with the graft horizontal cell processes invaginated in the horizontal cell ablated retinas. As suggested by the multielectrode array recording, the removal of horizontal cells from the degenerated retinas prior to transplantation seemed to facilitate the functional synapse formation between host bipolar cells and graft photoreceptors. The host ganglion cells showed stronger light responses with better signal-to-noise ratio compared to the regular transplantation preparation without horizontal cell disturbance reported previously. This observation indicates the residual horizontal cells may be short of the ability to form new synapses and in contrast physically block the interaction of host bipolar cells and graft photoreceptors upon transplantation. The clearance of these residual horizontal cell processes at the outer plexiform layer may hence allow the graft horizontal cells to be involved in the newly formed synapses.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The aimed pilot study of retinal organoid transplantation in host retinas with and without horizontal cells (by conditional horizontal cell ablation after complete photoreceptor degeneration) has been conducted with functional (multielectrode array recording) and morphological characterization.
Upon the re-positioning of the researcher, the electrophysiology setups for retinal functional assay and mouse lines for targeted recording have been newly established in the current facility during the past year.
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| Strategy for Future Research Activity |
As the researcher has re-positioned last year, in the third year of this project, the interaction among amacrine cells, bipolar cells and horizontal cells in various retinal degeneration models will be focused. With the newly established electrophysiology setups, including patch clamp recording and multielectrode array system, in the current facility, the inhibitory inputs from amacrine/horizontal cells into bipolar cells under photoreceptor degeneration will be investigated, in combination of various amacrine cell subtype knockout mouse line established in the lab. This results are expected to provide insight on how the inhibitory retinal neurons affect the synaptic reconnection between host bipolar cells and graft photoreceptor cells upon retinal cell/organoid transplantation therapy.
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