MicroRNA-125b overexpression in pseudoexfoliation syndrome.

Background: MicroRNAs (miRs) are small non-coding RNAs. MiR-125b has been described as being downregulated in cataract tissue when compared to a transparent lens.

Objectives: The aims of the study were: 1) to establish the expression of miR-125b in cataracts complicated by pseudoexfoliation syndrome (PEX), glaucoma or PEX glaucoma; and 2) to determine whether any environmental factors influence miR-125b expression.

Material And Methods: Anterior lens capsules were obtained from 150 patients. The patients were subdivided into 1 of 4 groups: those with PEX (PEXg), those with primary open-angle glaucoma (Gg) and those with PEX glaucoma (PEXGg), plus gender-matched controls with cataracts alone (control group - Cg). Quantitative polymerase chain reaction (qPCR) expression of microRNA-125b was examined in every group.

Results: The mean age of the 150 patients was 75.18 years (standard deviation (SD) ±9.12 years). Our investigation indicated, for the first time, that miR-125b expression was increased 3.33 times in the PEXg (p = 0.015). The quantitative analysis of miR-125b expression conducted between combined groups of all the patients that have PEX syndrome (with or without glaucoma) and the Cg revealed a statistically significant difference (p = 0.04). Lower miR-125b expression was found in the patients who smoked compared to those who did not (p = 0.01).

Conclusions: Our data revealed the possible role of miR-125b in PEX syndrome development. There are 2 possible interpretations of these results: either the co-existence of PEX acts as a moderator of miR-125b expression in the anterior lens capsule, or increased expression of miR-125b can play a role in the pathogenesis of PEX.