PDF(Pubmed)
Abstract：
Epiretinal membranes (ERMs) are the result of fibro-cellular proliferation that cause distortion and impairment of central vision. We hypothesized that select microRNAs (miRs) regulate retinal fibro-proliferation and ERM formation. Following IRB approval, a pilot study was performed in patients presenting for retina surgery with and without clinical ERMs. Total RNA was isolated from ERM tissue and controls from non-ERM vitreous and subjected to miR profiling via microarray analysis. MiR-494 was identified as the only miR selectively expressed at significantly greater levels, and in silico analysis identified p27 as a putative fibroproliferative gene target of miR-494. In vitro testing of miR-494 and p27 in fibrotic transformation was assessed in spontaneously immortalized human retinal pigment epithelial (RPE) and human Müller cell lines, stimulated to transform into a fibroproliferative state via transforming growth factor beta (TGFβ). Fibroproliferative transformation was characterized by de novo cellular expression of alpha smooth muscle actin (αSMA). In both RPE and Müller cells, both TGFβ and miR-494 mimic decreased p27 expression. In parallel experiments, transfection with p27 siRNA augmented TGFβ-induced αSMA expression, while only in RPE cells did co-transfection with miR-494 inhibitor decrease αSMA levels. These results demonstrate that miR-494 augments fibrotic transformation in both Müller cells and RPEs, however only in RPEs does miR-494 mediate fibrotic transformation via p27. As p27 is known to regulate cellular proliferation and differentiation, future studies should extend clinical testing of miR-494 and/or p27 as a potential novel non-surgical therapy for ERMs, as well as identify relevant miR-494 targets in Müller cells.
摘要：
视网膜膜（ERM）是纤维细胞增殖的结果，导致中央视觉扭曲和损害。我们假设选择microRNAs(miRs)调节视网膜纤维增殖和ERM形成。IRB批准后，我们在接受视网膜手术且有或无临床ERM的患者中进行了一项初步研究,从ERM组织和非ERM玻璃体对照中分离总RNA,并通过微阵列分析对其进行miR谱分析.miR-494被鉴定为唯一以显著更高水平选择性表达的miR。计算机模拟分析将p27鉴定为miR-494的推定的纤维增殖性基因靶标。在自发永生化人视网膜色素上皮（RPE）和人Müller细胞系中评估了纤维化转化中miR-494和p27的体外测试，通过转化生长因子β（TGFβ）刺激转化为纤维增生状态。纤维增殖转化的特征在于α平滑肌肌动蛋白(αSMA)的从头细胞表达。在RPE和Müller细胞中，TGFβ和miR-494模拟物均降低p27表达。在平行实验中,p27siRNA转染增强TGFβ诱导的αSMA表达，而仅在RPE细胞中与miR-494抑制剂共转染降低了αSMA水平。这些结果表明，miR-494增强了Müller细胞和RPE中的纤维化转化，然而，只有在RPE中，miR-494通过p27介导纤维化转化。已知p27调节细胞增殖和分化，未来的研究应该扩展miR-494和/或p27作为ERM潜在的新型非手术疗法的临床试验，以及在Müller细胞中鉴定相关的miR-494靶标。
