Autophagy dysregulation mediates the damage of high glucose to retinal pigment epithelium cells

AIM: To observe the role and mechanism of autophagy in retinal pigment epithelial cell ( RPE) damaged by high glucose, so as to offer a new idea for the treatment of diabetic retinopathy (DR). METHODS: ARPE-19, a human RPE cell line cultured in vitro was divided into the normal control (NC), autophagy inhibitor 3-methyladenine (3-MA), high-glucose (HG), and HG+3-MA groups. Cell viability was detected by CCK-8 assay and the apoptosis rate was measured by flow cytometry. The protein expressions of apoptosis markers, including Bax, Bcl-2, and Caspase-3, as well as autophagy marker including microtubule-related protein 1 light chain 3 (LC3), p62, and mechanistic target of rapamycin (mTOR) were detected by Western blotting. Autophagic flux was detected by transfection with Ad-mCherry-GFP-LC3B. RESULTS: Under high glucose conditions, the viability of ARPE-19 was decreased, and the apoptosis rate increased, the protein expressions of Bax, Caspase-3, and LC3-II/LC3-I were all increased and the expressions of Bcl-2, p62 and p-mTOR decreased, and autophagic flux was increased compared with that of the controls. Treatment with 3-MA reversed all these changes caused by high glucose. CONCLUSION: The current study demonstrates the mechanisms of cell damage of ARPE-19 through high glucose/mTOR/autophagy/ apoptosis pathway, and new strategies for DR may be developed based on autophagy regulation to manage cell death of RPE cells.

Automated summary

The study investigated the role and mechanism of autophagy in retinal pigment epithelial cells damaged by high glucose, revealing decreased cell viability, increased apoptosis, and activated autophagic flux under high glucose conditions. These changes were reversed by treatment with an autophagy inhibitor. New strategies for managing diabetic retinopathy may be developed based on autophagy regulation.