Expression of the microRNAs hsa-miR-15a and hsa-miR-16-1 in lens epithelial cells of patients with age-related cataract.

This study aimed to examine and analyze the expression levels of hsa-miR-15a and hsa-miR-16-1 in lens epithelial cells from patients with age-related cataract to understand better the roles of these microRNAs in the pathogenesis of this disease. Lens epithelial cells of 60 age-related cataract patients (including 20 with cortical cataracts, 20 with nuclear cataracts, and 20 with posterior subcapsular cataracts) and 20 normal patients were included in the study. Real-time PCR was used to detect the expression of hsa-miR-15a-5p, hsa-miR-15a-3p, hsa-miR-16-1-5p, and hsa-miR-16-1-3p. Expression of the target genes of these microRNAs, namely bcl-2 and mcl-1, was also evaluated. hsa-miR-15a-5p, hsa-miR-15a-3p, and hsa-miR-16-1-5p were expressed at low levels in normal lens epithelial cells but at significantly higher levels in corresponding cells of patients with cortical, nuclear, or posterior subcapsular cataracts (P < 0.01). hsa-miR-16-1-3p was expressed at relatively high levels in normal lens epithelial cells but significantly decreased expression, or none at all, was detected in cells of patients from each cataract group (P < 0.01). Concerning their target genes bcl-2 and mcl-1, expression was detectable in normal lens epithelial cells, but their levels were significantly decreased in cataract patients, irrespective of type (P < 0.01). Expression of hsa-miR-15a-5p, hsa-miR-15a-3p, and hsa-miR-16-1-5p rose in lens epithelial cells in the three types of age-related cataract, which may suppress the expression of the anti-apoptotic genes bcl-2 and mcl-1, thereby contributing to the pathogenesis of age-related cataract through apoptosis.