METHODS: The different ages of miRNAs in lens were extracted and samples were divided into four groups: infant lens group(lens from non-ophthalmopathy infant), congenital cataract group(lens from cataract infant), young and middle-aged group(lens from young cataract patients)and senile group(lens from age-related cataract patients). The expression of the 10 miRNAs was detected in the four groups using stem-loop RT-PCR respectively.

RESULTS: In normal infant's lens, the expression of miR-184 was the highest. Compared with the normal infant's lens tissue, the miR-184 and miR-182 in congenital cataract patients increased, the miR-124 and miR-204 decreased. Compared with the children's lens with cataract, the expression of miR-204, 124 and let-7d in young and middle-aged cataract patients increased, while the expression of miR-184, 183 and let-7a decreased. In the lens of senile cataract patients, all of the 10 miRNAs changed. The expression of miR-182, 204, 124 increased, while miR-184, 181b, 183, 125b, let-7a/b/d decreased.

CONCLUSION: There are significant differences in the expression of miRNA in the lens of children and cataract patients of different ages. Some miRNAs are related to the normal morphology, function and certain pathological conditions of the lens. This study provided a theoretical basis of further study on the role of miRNAs in maintaining the normal function of the young children's lens and the formation of cataracts at different ages.