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

  • Int J Ophthalmol. 2021 Jun 18;14(6):805-811. doi: 10.18240/ijo.2021.06.04.
Qian Zhang  1 ,  Hong-Song Li  2 ,  Rong Li  3 ,  Jun-Hui Du  4 ,  Cong Jiao  3
Affiliations
  • 1. Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Key Laboratory of Aerospace Medicine of Ministry of Education, Air Force Medical University, Xi'an 710032, Shaanxi Province, China.
  • 2. Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China.
  • 3. Department of Ophthalmology, the First Affiliated Hospital of Xi'an Medical University, Xi'an 710077, Shaanxi Province, China.
  • 4. Department of Ophthalmology, Xi'an Ninth Hospital Affiliated to Medical College of Xi'an Jiaotong University, Xi'an 710054, Shaanxi Province, China.
PMID: 34150534 DOI: 10.18240/ijo.2021.06.04
Abstract

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.

Keywords
apoptosis; autophagy; diabetic retinopathy; retinal pigment epithelial cell; the mechanistic target of rapamycin (mTOR).
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