Therapeutic Potential of Stem Cells for Treating Retinal Ganglion Cell Degeneration in Optic Neuropathies

Retinal ganglion cell (RGC) degeneration is a symbol of optic neuropathies, leading to progressive vision loss with limited therapeutic options. Stem cell-based medicines have gained recognition as a potential breakthrough strategy for neuro-protection and regeneration in such conditions. This research investigated the efficacy of Human Periodontal Ligament-Derived Stem Cells (PDLSCs) and the Extracellular Vesicles (EVs) of Optic Neuropathies in a rat model. PDLSCs were isolated, characterized, and transplanted either as whole cells or via their secreted EVs. The neuroprotective and regenerative effects were assessed at 15, 61, and 120 days post-injury through histological analysis, RGC survival counts, axonal regeneration assays, and functional restoration of visual pathways. Additionally, serum-deprived PDLSCs were used to evaluate their impact on neuroprotection compared to regular PDLSCs. PDLSC transplantation significantly enhanced RGC survival and reduced apoptosis for up to 120 days post-injury, with marked improvements observed at 15 and 61 days. Axonal regeneration along the optic nerve was evident, particularly at 120 days, demonstrating a sustained regenerative response. Similar neuroprotective effects were observed with serum-deprived PDLSCs, suggesting a potential role of paracrine signaling in their therapeutic action. However, transplantation of EVs isolated from PDLSCs failed to induce significant neuroprotection or axonal regeneration, indicating that direct cellular interaction can be essential for optimal therapeutic outcomes. These results support further exploration of PDLSCs as a viable cell therapy approach for neurodegenerative conditions affecting the optic nerve.