Preservation of vision after chemically induced retinal ganglion-like-cell transplantation.

Optic neuropathies are a leading cause of irreversible blindness in children and adults, primarily due to the loss of retinal ganglion cells (RGCs). Currently, there are no effective treatments available to preserve vision in affected patients. Although RGCs derived from pluripotent stem cells present a promising therapeutic strategy, the efficient generation of human RGCs remains a significant challenge. Here, we report a facile method using a combination of five small molecules to reprogram human primary fibroblasts into Chemically Induced RGC-like Cells (CiRGCs), which we term CiRGCs, within just four days. scRNA-Seq analysis revealed that these in vitro-generated CiRGCs express canonical RGC markers such as Pou4f1, Brn3b, Rbpms, and Sncg, as well as several RGC subtype-specific genes. Notably, CiRGCs cluster near native RGCs derived from day 59 fetal retina from published datasets. Furthermore, scATAC-Seq showed open chromatin at RGC-specific promoters and closed chromatin at fibroblast-specific promoters in CiRGCs, confirming successful lineage conversion. Functionally, transplantation of CiRGCs into models of excitotoxic RGC injury led to improved electrophysiological responses for up to 2.5 months possibly through a neuroprotective mechanism. Mechanistically, scRNA-Seq analysis indicated that CiRGC reprogramming proceeds via activation of potential youthful cellular pathways in intermediate cell clusters. In summary, our results establish a rapid, chemical-based strategy for CiRGC reprogramming and highlight its potential as a novel cell therapy approach for treating optic neuropathies, including glaucoma, where RGC loss is the final common pathway.