ABSTRACT
Retinal degenerative diseases affect millions of people worldwide, and legal blindness is generally associated with the loss of cone photoreceptors located in the central region of the retina called the macula. Currently, there is no treatment to replace the macula. Addressing this unmet need, we employed control isogenic and hypoimmunogenic induced pluripotent stem cell lines to generate spontaneously polarized retinal sheets (RSs). RSs were enriched in retinal progenitor and cone precursor cells, which could differentiate into mature S- and M/L-cones in long-term cultures. Single-cell RNA-seq analysis showed that RSs recapitulate the ontogeny of the developing human retina. Isolation of neural rosettes for sub-retinal transplantation effectively eliminated unwanted cells such as RPE cells. In a porcine model of chemically induced retinal degeneration, grafts integrated the host retina and formed a new, yet immature, photoreceptor layer. In one transplanted animal, functional and immunohistochemical assays suggest that grafts exhibited responsiveness to light stimuli and established putative synaptic connections with host bipolar neurons. This study underscores the potential and challenges of RSs for clinical applications.
Footnotes
Author contributions
Conceptualization: A.B., K.M., M.G., J.-F.B., A.K., R. Hanna, G.B.; Methodology: A.B., K.M., R. Hamam, A.P., M.G., J.-F.B., A.K., R. Hanna, G.B.; Software: R. Hanna; Validation: A.B., K.M., A.P., J.-F.B., R. Hanna, G.B.; Formal analysis: R. Hanna; Investigation: K.M., R. Hamam, A.P., M.G., J.-F.B., A.K.; Resources: K.M., A.K.; Data curation: K.M., R. Hamam, A.P., A.K., R. Hanna, G.B.; Writing - original draft: A.B., R. Hanna, G.B.; Writing - review & editing: A.B., R. Hanna, G.B.; Visualization: A.P., R. Hanna; Supervision: M.G., G.B.; Project administration: K.M., G.B.; Funding acquisition: M.G., J.-F.B., G.B.
Funding
This work was supported by grants from the Stem Cell Network Canada (FY19/DT9 and FY20/FBP-1), donations from the Felicia and Arnold Aaron Foundation, and partnerships with StemAxon and Healios K.K. corporations. The initiation of this project was supported by a historical donation from the Turmel Family Foundation for macular degeneration research.
Data availability
scRNA-seq data have been deposited in GEO under accession number GSE228436.
