Front Cell Dev Biol. 2026 Sep 28;14:1891491. doi: 10.3389/fcell.2026.1891491. eCollection 2026.
ABSTRACT
BACKGROUND: Hypoxic injury is a critical pathological factor in various retinal degenerative diseases, leading to mitochondrial dysfunction and irreversible loss of retinal neurons. This study investigated the neuroprotective potential of Icariin-loaded extracellular vesicles (EV_ICA) using both R28 retinal progenitor cells and human embryonic stem cell (hESC)-derived retinal organoids.
METHODS: EV_ICA were isolated and characterized by morphology, EV marker expression, and zeta potential analysis. A CoCl2-induced hypoxic injury model was established in R28 cells and hESC-derived retinal organoids to evaluate the therapeutic effects of EV_ICA. Gene and protein expression analyses, bulk RNA sequencing (RNA-seq), gene set enrichment analysis (GSEA), mitochondrial ROS measurements, and intracellular ATP assays were performed to assess neuroprotective efficacy and mitochondrial function.
RESULTS: EV_ICA exhibited typical spherical morphology, expressed standard EV markers, and showed a shift toward a less negative zeta potential compared to Naïve EV. In hypoxia-injured retinal models, EV_ICA significantly restored the expression of key retinal and neuroprotective markers, including Syntaxin12, NeuN, Vegf, Rbpms, Brn-3a, and Bdnf, while suppressing Hif-1α accumulation. Transcriptomic and GSEA analyses revealed that EV_ICA reactivated biological pathways associated with phototransduction, visual perception, and retinal development that were impaired under hypoxic conditions. Furthermore, EV_ICA improved mitochondrial homeostasis by up-regulating mitochondrial-related genes, reducing mitochondrial ROS accumulation, and recovering intracellular ATP production.
CONCLUSION: These findings demonstrate that EV_ICA exerts neuroprotective effects by preserving mitochondrial quality control and restoring functional retinal gene programs under hypoxic stress. EV_ICA may therefore serve as a promising therapeutic candidate for hypoxia-related retinal degeneration and provide potential applications for cell-free regenerative medicine.
PMID:42866352 | PMC:PMC13656086 | DOI:10.3389/fcell.2026.1891491