Exposure to subthreshold dose of UVR‐B induces apoptosis in the lens epithelial cells and does not in the lens fiber cells

Abstract

PurposeThe purpose of this study is to investigate which part of the lens in vivo exposure to subthreshold dose of UVR‐B induces apoptosis in.MethodsTwenty 6‐week‐old female albino Sprague‐Dawley rats were exposed to subthreshold dose (1 kJ/m2) of UVR‐B unilaterally and sacrificed at 120 h after exposure. Lenses were enucleated and dissected on three regions: the lens epithelium, the cortex and the nucleus. The lens nucleus then was removed. Apoptosis markers p53 and caspase 3 were used to study apoptosis in the lens epithelium and the cortex. qRT‐PCR and Western Blot were utilized to analyze the lenses.ResultsTP53 and CASP3 mRNA expressions are increased in exposed lenses, both in the lens epithelium and the cortex regions, in relation to non‐exposed lenses. Expression of p53 protein is increased in exposed lens epithelium in relation to non‐exposed lens epithelium. Caspase 3 protein is expressed in exposed lens epithelial cells whereas it is not expressed in non‐exposed lens epithelial cells. p53 and caspase 3 proteins are not expressed in either exposed or non‐exposed lens fiber cells.ConclusionsExposure to UVR‐B increases mRNA transcription of apoptosis marker p53 in vivo in both regions of the lens and of apoptosis marker caspase 3 in the lens cortex. Exposure to UVR‐B increases p53 and caspase 3 proteins’ expression in the lens epithelium. In vivo exposure to subthreshold dose of UVR‐B induces apoptosis in the lens epithelial cells and does not in the lens fiber cells.