长链非编码RNA-NEAT1和MALAT1作为ceRNA参与后发障形成的分子生物学调节机制的研究

Posterior capsule opacification (PCO) is a common postoperative complication of cataract surgery; is generally associated with wrinkling/contraction of the posterior capsule and the pathological progression of postoperative residual lens epithelial cells (LECs), including proliferation, migration, and epithelial–mesenchymal transition (EMT). We previously reported that the expression of miR-181a and miR-26b is downregulated in human PCO-attached LECs and that miR-181a and miR-26b can inhibit the proliferation, migration, and EMT of lens epithelial cells. We then used microarray analysis to compare lncRNA expression levels between human PCO-attached LECs and normal-attached LECs, and found a large number long non-coding RNA expression differences, which NEAT1 and MALAT1 significantly upregulated. This study intends to build a variety of low expression or overexpression eukaryotic expression vector used in PCO rats and lens epithelial cells. Then we will explore the non-coding RNA and the target gene on the proliferation, migration, EMT, autophagy of lens epithelial cells by low expression or overexpression NEAT1, MALAT1, miR-181a, miR-26b and these miRNA target genes of ZEB1, Twist1, EZH2, Rheb. Based on the above findings and preliminary work, we will reveal the mechanism of PCO formation which is NEAT1 and MALAT1 as competing endogenous RNAs controlling miR-181a and miR-26b by competitively binding ZEB1, Twist1, EZH2, Rheb, and then stimulating the proliferation, migration, and EMT of lens epithelial cells.

后囊膜混浊（PCO）是白内障术后常见并发症，本组前期工作发现，miR-181a和miR-26b通过抑制晶状体上皮细胞（LECs）的增殖、迁移、上皮间充质转化（EMT）进而抑制PCO的发生；PCO贴附的LECs与无PCO的LECs对比，大量长链非编码RNA差异表达，其中NEAT1和MALAT1表达明显上调。本研究拟构建各种真核表达载体应用于PCO大鼠和晶状体上皮细胞，通过低表达或过表达NEAT1、MALAT1、miR-181a、miR-26b以及这些miRNA的靶基因ZEB1、Twist1、EZH2、Rheb，探讨非编码RNA和靶基因对LECs的增殖、迁移、EMT和自噬等多种生物学功能的调控机制。基于以上研究结果和前期工作，揭示NEAT1和MALAT1作为竞争性内源性RNA通过对miR-181a和miR-26b的竞争性结合调控ZEB1、Twist1、EZH2、Rheb，参与PCO形成的机制。

晶状体后囊膜混浊 (posterior capsular opacification, PCO)也称后发性白内障 (secondary cataract)，它是白内障摘除术后再度视力下降甚至引起失明的主要并发症。目前研究认为，晶状体上皮细胞增殖、迁移、上皮间充质转化 (epithelial-mesenchymal transition, EMT)是PCO的主要原因。近年来，大量的实验研究证明microRNAs、mRNA、假基因、长链非编码 RNA、circular RNA之间形成了复杂的网络，通过这种网络相互调节各自的表达水平。我们推测lncRNA作为竞争性内源性 RNA模式 (competing endogenous RNAs, ceRNA)通过对miRNA的竞争性结合，实现了lncRNA与mRNA之间的对话和交流，对晶状体上皮细胞的增值、迁移和EMT起调控作用，并进行了实验，取得实验进展：. 一方面，我们的研究证明lncRNA NEAT1作为ceRNA调控各种转录因子参与后发障形成的分子生物学机制：NEAT1通过对miR-34a 和miR-204的竞争性结合分别调控Snail1和Zeb1参与LECs的EMT。另一方面，揭示lncRNA MALAT1参与后发障形成的机制：MALAT1通过对miR-26a的竞争性结合调控Smad4参与LECs的EMT。最后，我们的实验还拓展性发现：EGF刺激晶状体上皮细胞的EMT：EGF刺激晶状体上皮细胞，能够上调Myc的表达，抑制miR-26b，进而活化EZH2刺激晶状体上皮细胞EMT，最终导致PCO发生的机制。. 通过本研究我们不仅探讨了lncRNA NEAT1 和lncRNA MALAT1参与后发障形成的分子生物学机制，还揭示了竞争性内源性 RNA模式参与后发障形成的机制，为今后临床中应用NEAT1 和MALAT1抑制剂控制PCO的发生发展提供了理论依据，为将来转化提供依据。