Genome-edited retinal organoids restore host bipolar connectivity in the primate macula

Ozaki, A.; Kawai, A.; Akiba, R.; Okayama, S.; Ohno, N.; Kajita, K.; Masuda, T.; Yokota, S.; Ito, S.-i.; Peiyan, D.; Onoue, K.; Yonemura, S.; Kondo, M.; Kurimoto, Y.; Fu, Y.; Mandai, M.

doi:10.1101/2025.08.21.671525

bioRxiv · 10.1101/2025.08.21.671525

Genome-edited retinal organoids restore host bipolar connectivity in the primate macula

Ozaki, A.·Kawai, A.·Akiba, R.·Okayama, S.·Ohno, N.·Kajita, K.·Masuda, T.·Yokota, S.·Ito, S.-i.·Peiyan, D.·Onoue, K.·Yonemura, S.·Kondo, M.·Kurimoto, Y.·Fu, Y.·Mandai, M.

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Abstract

Retinal organoids (ROs) represent a promising regenerative strategy for restoring vision in retinal degenerative diseases, but whether host cone bipolar cells (BCs) in the primate macula can rewire with transplanted photoreceptors remains unresolved. Here, we transplanted genome-edited human retinal organoids lacking ON-BCs (Islet-1-/- ROs) into a non-human primate macular degeneration model. Remarkably, host rod and cone BCs extended dendrites toward grafted photoreceptors, forming functional synapses confirmed by immunohistochemistry, ultrastructural imaging, and focal macular electroretinography. Both ON- and OFF-pathway connectivity was rebuilt, providing the first demonstration of host-graft synaptic integration in the primate macula. These results establish that primate cone circuits retain a surprising capacity for rewiring and highlight genome-edited ROs as a powerful platform for vision restoration. Our findings represent a critical translational step toward stem cell-based therapies capable of repairing central vision in patients with advanced macular degeneration.

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Ozaki, A., Kawai, A., Akiba, R., Okayama, S., Ohno, N., Kajita, K., Masuda, T., Yokota, S., Ito, S.-i., Peiyan, D., Onoue, K., Yonemura, S., Kondo, M., Kurimoto, Y., Fu, Y., Mandai, M.. 2025-08-26. Genome-edited retinal organoids restore host bipolar connectivity in the primate macula. https://doi.org/10.1101/2025.08.21.671525

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