Effects of PU-91 and Quercetin in Age-related Macular Degeneration, Keratoconus, and Glaucoma cybrids

Abstract

Purpose : Introduction:
Mitochondria are the main source of ATP production through oxidative phosphorylation. Pathologic mitochondrial metabolism induces elevated levels of reactive oxygen species (ROS) and alters expression of transcription factors that regulate many pathological pathways. Mitochondrial damage plays a significant role in age-related macular degeneration (AMD), glaucoma (Glc) and keratoconus (KC). PU-91 is a mitochondria-stabilizing agent with a potential therapeutic role for AMD. Quercetin, a plant-derived flavanol found in fruits and vegetables, has considerable antioxidant and anti-inflammatory properties, making it potentially beneficial to reduce oxidative stress. We tested PU-91 and quercetin using the transmitochondrial cybrid cell lines, which have identical nuclei but different mitochondria from individuals.
Purpose:
To evaluate the possible effects of PU-91 and quercetin on the AMD, KC, and Glc cybrids compared to age-matched normal cybrids

Methods : Cybrids were created by fusion of the mitochondria-deficient (Rho0) ARPE-19 cells with the platelets derived from patients with AMD (n=5), KC (n=3), GLc (n=1), and normal age-matched (n=4) individuals. Cells were cultured in 96-well plates (10,000 cells/well) and treated with PU-91 200 µM, quercetin 20 µM or combined [PU-91 plus quercetin] for 48 hours. The vehicle control was DMSO. ROS Levels: The H2DCFDA solution (100µl/well) was added to each well, plates were read via the fluorescent plate reader with the excitation (EX, 492nm) and emission (EM, 520nm) wavelength. Cellular metabolism: MTT assay reagent (10µl) was added/well and plates incubated in 37°C for 3 hours. After adding 200 μl/well of DMSO, plates were analyzed (signal at 570 nm and reference at 630 nm) with the absorbance plate reader. Statistical analyses were by GraphPad Prism, using one way ANOVA Tukey test.

Results : AMD cybrids: Treatment of PU-91 alone and combined [PU-91 plus quercetin] increased cellular viability and reduced intracellular ROS levels. Glc cybrid: PU-91 alone increased cell viability. Aged NL cybrids: PU-91 alone, quercetin alone and combined [PU-91 plus quercetin] decreased ROS levels. KC cybrids were not affected with any treatment.

Conclusions : PU-91 and combined [PU-91 plus quercetin] may have therapeutic effects for improving damaged AMD, glaucoma and aging mitochondria.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.