Protective effects of 17β-estradiol on Benzo(e)pyrene[B(e)P]-induced toxicity in ARPE-19 cells

Abstract

Purpose:The aim of this study was to examine the effect of 17β-estradiol on Benzo(e)pyrene [B(e)P]-induced toxicity in ARPE-19 cells.Methods:We pretreated ARPE-19 cells with 20 nM and 40 nM 17β-estradiol for 6 hours, followed by addition of 300 μM B(e)P for additional 24 hours. Cell viability was measured using Trypan blue dye-exclusion assay. JC-1 assay was performed to measure mitochondrial membrane potential (ΔΨm). For a quantitative estimation of cell death, apoptotic markers such as caspase-3/7, caspase-9, and caspase-12 were measured.Results:Our results demonstrated that when treated with B(e)P, the viability and ΔΨm of ARPE-19 cells declined by 25% and 63%, respectively (P < 0.05). However, pretreating with 17β-estradiol increased the viability of ARPE-19 cells by 21% (20 nM) and 10% (40 nM) (P < 0.05). Furthermore, the significantly reduced ΔΨm in βE+B(e)P treated cells ARPE-19 cells was restored by pre-treatment with 17β-estradiol- ΔΨm was increased by 177% (20 nM) and 158% (40 nM) (P < 0.05). We further observed a significant up-regulation in the activity of Caspases-3/7, -9, and -12 in B(e)P-treated ARPE-19 cells. However, 17β-estradiol treatment significantly reduced the activity of all apoptotic markers (P < 0.05).Conclusion:In conclusion, our results demonstrate that 17β-estradiol protects ARPE-19 cells against B(e)P-induced toxicity by decreasing apoptosis, preventing cell death, and restoring mitochondrial membrane potential.

Effects of E-Cigarette Refill Liquid Flavorings with and without Nicotine on Human Retinal Pigment Epithelial Cells: A Preliminary Study

“…In addition, as the baseline mitochondrial function and response to oxidative stress has been shown to differ between primary and immortalized airway epithelial cells [ 73 ], it is possible that primary RPE cells and immortalized hTERT-RPE1 cells might show differential response to e-cigarettes as compared to ARPE-19 cells due to differential effects on mitochondrial function; a comparison to confirm this hypothesis would be interesting for future studies. Although ARPE-19 can be differentiated and fully polarized with melanization after 4 months of culture [ 74 , 75 ] using a specialized medium with 1% serum or in a shorter span of 1 week by supplementation of exogenous chemical, nicotinamide, to induce differentiation [ 76 ], the use of undifferentiated ARPE-19 cells is a relatively less time-consuming and convenient model and has been validated in several previous studies that evaluated components of cigarette exposure [ 38 , 77 ]. In addition, ARPE-19 cell line is a well-established model for human RPE cells [ 78 , 79 ] and expresses RPE cell-specific markers RPE65, cellular retinaldehyde binding protein-1 (CRALBP), and keratin-18 [ 80 ].…”