Dynamic transcriptomic remodeling in grafted human neural progenitor cells uncovers mechanisms for vision preservation in a rat model of retinitis pigmentosa

Human neural progenitor cells (hNPCs) show promise in slowing retinal degeneration and are currently being tested in clinical trials for retinitis pigmentosa (RP). However, the long-term fate of grafted hNPCs and their interaction with host retinal cells remain unclear. Here, we used single-cell transcriptomics to investigate temporal gene expression changes in grafted hNPCs and host retinal cells following subretinal injection into a rodent model of RP, revealing dynamic transcriptomic changes in the degenerative retinal environment. Grafted hNPCs primarily differentiate into an astroglial phenotype and mature over time, contributing to photoreceptor protection through trophic factor secretion, metabolic modulation, suppression of apoptosis, oxidative stress, and inflammation, alongside extracellular matrix remodeling. CellChat analysis revealed a decline in intercellular signaling and communication strength over time, correlating with weakened hNPC-host interactions. These findings suggest that enhancing trophic factor support, particularly MANF, and improving the host retinal environment are critical for sustaining long-term vision preservation. Stem cell therapy for retinal degeneration shows promise but waning efficacy. Here, authors show that grafted hNPCs remodel in the degenerating retina, with reduced graft-host communication and trophic signaling, highlighting the importance of the host environment for long term efficacy.