Exosomes Derived from Stem Cells from Human Exfoliated Deciduous Teeth Attenuate Glycation-Induced Oxidative Stress and Cytotoxicity in Neuronal Cells.

OBJECTIVES: Advanced glycation end products (AGEs) induce oxidative stress and cellular injury through excessive reactive oxygen species (ROS), contributing to aging- and diabetes-related degenerative conditions. Exosomes derived from stem cells from human exfoliated deciduous teeth (SHED) exhibit regenerative and cytoprotective properties. This study aimed to investigate the effects of SHED-derived exosomes on AGE-induced oxidative stress and cytotoxicity in neuronal cells. MATERIALS AND METHODS: Exosomes were isolated from SHED-serum-free conditioned medium by differential ultracentrifugation and characterized using transmission electron microscopy, nanoparticle tracking analysis, and Western blotting for CD81, TSG101, and HSP70. Uptake of PKH26-labeled exosomes by SK-N-SH neuroblastoma cells was evaluated using confocal microscopy. AGEs were generated by incubating bovine serum albumin with glucose and confirmed by fluorescence analysis. Cell viability and intracellular ROS levels were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 2',7'-dichlorodihydrofluorescein diacetate (DCHF-DA) assays, respectively. Proteomic analysis was performed to identify proteins associated with cytoprotective activity. STATISTICAL ANALYSIS: Data were presented as mean ± standard deviation from triplicate experiments. Statistical analysis was performed using one-way analysis of variance followed by appropriate post hoc tests. A p-value of < 0.05 was considered statistically significant. RESULTS: SHED-derived exosomes exhibited a typical cup-shaped morphology with sizes ranging from 37 to 200 nm and expressed canonical exosomal markers. SK-N-SH cells efficiently internalized SHED-derived exosomes. AGE treatment induced dose-dependent cytotoxicity (IC50 = 5.24 mg/mL) and significantly increased intracellular ROS levels. Treatment with SHED-derived exosomes at 30 to 50 µg/mL significantly improved cell viability, whereas 20 µg/mL significantly reduced AGE-induced ROS accumulation (p < 0.05). Proteomic analysis identified proteins associated with oxidative stress response, cellular repair, and cell survival pathways. CONCLUSION: Exosomes derived from SHED attenuated AGE-induced oxidative stress and cytotoxicity in neuronal cells. These findings suggest the potential application of SHED-derived exosomes as a cell-free approach for oxidative stress-related cellular injury.