Background: Glaucoma is the second leading cause of blindness in the world and is characterized by optic neuropathy and degeneration of retinal ganglion cells (RGCs). Our preliminary research found that acteoside can inhibit autophagy-induced apoptosis of RGCs via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. However, it is unclear how acteoside activates the PI3K/AKT signaling pathway to prevents RGCs autophagic apoptosis.
Methods: Animal and cell models were used in this study. Hematoxylin-eosin staining revealed pathological histology of retinas. The number of RGCs in retinas was counted using immunofluorescence. Malondialdehyde and superoxide dismutase were determined using enzyme-linked immunosorbent assay kits. Flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining were used to detect cell apoptosis. The reactive oxygen species was determined by the Flow cytometry. The proteins were determined by Western blot.
Results: The results showed that acteoside treatment significantly reduced RGC loss, oxidative stress, and autophagy, thereby preventing glaucoma exacerbation. Acteoside reversed caveolin 1 (Cav1) expression and PI3K/AKT signaling activation, according to Western blot results. Cav1 knockdown also reversed acteoside's effects on RGC loss, PI3K/AKT signaling pathway activation, autophagy and oxidative stress. Notably, 3-methyladenine, a PI3K inhibitor, reversed the effects of acteoside and Cav1 overexpression on RGC loss, oxidative stress, and autophagy.
Conclusions: These finding imply that acteoside alleviates RGC loss and oxidative stress by activating of the PI3K/AKT signaling pathway by upregulating Cav1.
Keywords: Acteoside; PI3K/AKT signaling pathway; caveolin 1; glaucoma; retinal ganglion cells (RGCs).
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