Active caspase-3 in the lens and its response to oxidative stress induced by in vivo exposure to UVR
Summary
Purpose
To determine the time evolution of active caspase-3 protein expression after exposure to low dose UVR-300 nm.
Methods
Forty rats were unilaterally exposed in vivo to 1 kJ/m2 UVR-300 nm for 15 min. All lenses were processed for immunohistochemistry. Time evolution of active caspase-3 expression was determined based on the differences in the probability of active caspase-3 expression at 0.5, 8, 16, and 24 hrs after the UVR exposure. A logistic model was introduced for the expression of active caspase-3.
Results
Active caspase-3 expression was higher in the exposed lenses. The mean differences between the exposed and non-exposed lenses were 0.17 ± 0.02, 0.20 ± 0.03, 0.21 ± 0.03, and 0.11 ± 0.04 (95% CI) for the 0.5, 8, 16, and 24 hr time groups, respectively. There was a difference when comparing the 0.5 and 24 hrs groups to the 8 and 16 hrs groups (95% CI = 0.06 ± 0.03). Exposure to UVR-300 nm impacted on the parameters of the logistic model by time.
Conclusions
Expression of active caspase-3 in the lens epithelium increased after UVR exposure. The peak of expression was around 16 hrs after the exposure. The logistic model predicts the impact of exposure to UVR on the spatial distribution of active caspase-3 expression, depending on time.
