Department of Biology and Center for Tissue Regeneration and Engineering, University of Dayton, Dayton, Ohio 45469-2320, USA.
Mol Med. 2012 May 9;18(1):528-38. doi: 10.2119/molmed.2011.00463.
The high recurrence rate of secondary cataract (SC) is caused by the intrinsic differentiation activity of residual lens epithelial cells after extra-capsular lens removal. The objective of this study was to identify changes in the microRNA (miRNA) expression profile during mouse SC formation and to selectively manipulate miRNA expression for potential therapeutic intervention. To model SC, mouse cataract surgery was performed and temporal changes in the miRNA expression pattern were determined by microarray analysis. To study the potential SC counterregulative effect of miRNAs, a lens capsular bag in vitro model was used. Within the first 3 wks after cataract surgery, microarray analysis demonstrated SC-associated expression pattern changes of 55 miRNAs. Of the identified miRNAs, miR-184 and miR-204 were chosen for further investigations. Manipulation of miRNA expression by the miR-184 inhibitor (anti-miR-184) and the precursor miRNA for miR-204 (pre-miR-204) attenuated SC-associated expansion and migration of lens epithelial cells and signs of epithelial to mesenchymal transition such as α-smooth muscle actin expression. In addition, pre-miR-204 attenuated SC-associated expression of the transcription factor Meis homeobox 2 (MEIS2). Examination of miRNA target binding sites for miR-184 and miR-204 revealed an extensive range of predicted target mRNA sequences that were also a target to a complex network of other SC-associated miRNAs with possible opposing functions. The identification of the SC-specific miRNA expression pattern together with the observed in vitro attenuation of SC by anti-miR-184 and pre-miR-204 suggest that miR-184 and miR-204 play a significant role in the control of SC formation in mice that is most likely regulated by a complex competitive RNA network.
后发性白内障（secondary cataract, SC）的高复发率是由于晶状体囊外摘除术后残留的晶状体上皮细胞的固有分化活性所致。本研究旨在鉴定在小鼠 SC 形成过程中 miRNA 表达谱的变化，并选择性地操纵 miRNA 表达以进行潜在的治疗干预。为了建立 SC 模型，对小鼠白内障手术进行了研究，并通过微阵列分析确定了 miRNA 表达模式的时间变化。为了研究 miRNA 对 SC 的潜在反调节作用，使用了晶状体囊袋体外模型。在白内障手术后的前 3 周内，微阵列分析显示 SC 相关的 miRNA 表达谱发生了 55 个 miRNA 的变化。在所鉴定的 miRNA 中，选择 miR-184 和 miR-204 进行进一步研究。通过 miR-184 抑制剂（anti-miR-184）和 miR-204 的前体 miRNA（pre-miR-204）对 miRNA 表达的操纵，减弱了晶状体上皮细胞的 SC 相关扩张和迁移以及上皮间质转化的迹象，如α-平滑肌肌动蛋白的表达。此外，pre-miR-204 减弱了 SC 相关转录因子 Meis 同源盒 2（MEIS2）的表达。对 miR-184 和 miR-204 的 miRNA 靶结合位点进行检查，发现了广泛的预测靶 mRNA 序列，这些序列也是与可能具有相反功能的其他 SC 相关 miRNA 的复杂网络的靶标。SC 特异性 miRNA 表达谱的鉴定以及在体外观察到的 anti-miR-184 和 pre-miR-204 对 SC 的减弱作用表明，miR-184 和 miR-204 在控制小鼠 SC 形成中发挥了重要作用，这种作用很可能受到复杂的竞争 RNA 网络的调节。
