Human primitive mesenchymal stem cell-derived retinal progenitor cells promoted neuroprotection and neurogenesis in rd12 mice

Retinal degenerative diseases (RDD) such as retinitis pigmentosa (RP) have no treatment. Stem cell-based therapies could provide promising opportunities to repair the damaged retina and restore vision. We investigated a novel approach in which human retinal progenitor cells (RPCs) derived from primitive mesenchymal stem cells (pMSCs) were examined to treat retinal degeneration in an rd12 mouse model of RP. Intravitreally transplanted cells improved retinal function and significantly increased retinal thickness. Transplanted cells homed, survived, and integrated to various retinal layers. They also induced anti-inflammatory and neuroprotective responses and upregulated neurogenesis genes. We found that RPCs were more efficacious than pMSCs in improving the retinal structure and function. RNA analyses suggest that RPCs promote neuroprotection and neuronal differentiation by activating JAK/STAT and MAPK, and inhibiting BMP signaling pathways. These promising results provide the basis for clinical studies to treat RDD using RPCs derived from pMSCs.