AU - Mansoor, S AU - Gupta, N AU - Falatoonzadeh, P AU - Kuppermann, B AU - Kenney, M TI - 2-ethylpyridine, a cigarette smoke component, causes mitochondrial damage in human retinal pigment epithelial cells in vitro PT - ORIG DP - 2014 Jan 1 TA - Indian Journal of Ophthalmology PG - 16-22 VI - 62 IP - 1 4099- https://journals.lww.com/ijo/pages/default.aspx/article.asp?issn=0301-4738;year=2014;volume=62;issue=1;spage=16;epage=22;aulast=Mansoor;type=0 4100- https://journals.lww.com/ijo/pages/default.aspx/article.asp?issn=0301-4738;year=2014;volume=62;issue=1;spage=16;epage=22;aulast=Mansoor AB - Purpose: Our goal was to identify the cellular and molecular effects of 2-ethylpyridine (2-EP, a component of cigarette smoke) on human retinal pigment epithelial cells (ARPE-19) in vitro. Materials and Methods: ARPE-19 cells were exposed to varying concentrations of 2-EP. Cell viability (CV) was measured by a trypan blue dye exclusion assay. Caspase-3/7 and caspase-9 activities were measured by fluorochrome assays. The production of reactive oxygen/nitrogen species (ROS/RNS) was detected with a 2',7'-dichlorodihydrofluorescein diacetate dye assay. The JC-1 assay was used to measure mitochondrial membrane potential (ΔΨm). Mitochondrial redox potential was measured using a RedoxSensor Red kit and mitochondria were evaluated with Mitotracker dye. Results: After 2-EP exposure, ARPE-19 cells showed significantly decreased CV, increased caspase-3/7 and caspase-9 activities, elevated ROS/RNS levels, decreased ΔΨm value and decreased redox fluorescence when compared with control samples. Conclusions: These results show that 2-EP treatment induced cell death by caspase-dependent apoptosis associated with an oxidative stress and mitochondrial dysfunction. These data represent a possible mechanism by which smoking contributes to age-related macular degeneration and other retinal diseases and identify mitochondria as a target for future therapeutic interventions.