Loscher Carol J, Hokamp Karsten, Kenna Paul F, Ivens Alasdair C, Humphries Peter, Palfi Arpad, Farrar G Jane
Smurfit Institute of Genetics, Trinity College Dublin, College Green, Dublin 2, Ireland.
Genome Biol. 2007;8(11):R248. doi: 10.1186/gb-2007-8-11-r248.
The role played by microRNAs (miRs) as common regulators in physiologic processes such as development and various disease states was recently highlighted. Retinitis pigmentosa (RP) linked to RHO (which encodes rhodopsin) is the most frequent form of inherited retinal degeneration that leads to blindness, for which there are no current therapies. Little is known about the cellular mechanisms that connect mutations within RHO to eventual photoreceptor cell death by apoptosis.
Global miR expression profiling using miR microarray technology and quantitative real-time RT-PCR (qPCR) was performed in mouse retinas. RNA samples from retina of a mouse model of RP carrying a mutant Pro347Ser RHO transgene and from wild-type retina, brain and a whole-body representation (prepared by pooling total RNA from eight different mouse organs) exhibited notably different miR profiles. Expression of retina-specific and recently described retinal miRs was semi-quantitatively demonstrated in wild-type mouse retina. Alterations greater than twofold were found in the expression of nine miRs in Pro347Ser as compared with wild-type retina (P < 0.05). Expression of miR-1 and miR-133 decreased by more than 2.5-fold (P < 0.001), whereas expression of miR-96 and miR-183 increased by more than 3-fold (P < 0.001) in Pro347Ser retinas, as validated by qPCR. Potential retinal targets for these miRs were predicted in silico.
This is the first miR microarray study to focus on evaluating altered miR expression in retinal disease. Additionally, novel retinal preference for miR-376a and miR-691 was identified. The results obtained contribute toward elucidating the function of miRs in normal and diseased retina. Modulation of expression of retinal miRs may represent a future therapeutic strategy for retinopathies such as RP.
微小RNA（miR）作为发育等生理过程以及各种疾病状态的常见调节因子所起的作用最近受到了关注。与RHO（编码视紫红质）相关的视网膜色素变性（RP）是导致失明的最常见遗传性视网膜变性形式，目前尚无治疗方法。关于RHO内的突变与最终通过凋亡导致光感受器细胞死亡之间的细胞机制知之甚少。
使用miR微阵列技术和定量实时RT-PCR（qPCR）对小鼠视网膜进行了全局miR表达谱分析。来自携带突变型Pro347Ser RHO转基因的RP小鼠模型视网膜以及野生型视网膜、脑和全身样本（通过汇集来自八个不同小鼠器官的总RNA制备）的RNA样本显示出明显不同的miR谱。在野生型小鼠视网膜中半定量地证实了视网膜特异性和最近描述的视网膜miR的表达。与野生型视网膜相比，Pro347Ser中9种miR的表达变化超过两倍（P < 0.05）。经qPCR验证，Pro347Ser视网膜中miR-1和miR-133的表达下降超过2.5倍（P < 0.001），而miR-96和miR-183的表达增加超过3倍（P < 0.001）。通过计算机模拟预测了这些miR的潜在视网膜靶标。
这是第一项专注于评估视网膜疾病中miR表达改变的miR微阵列研究。此外，还鉴定了miR-376a和miR-691对视网膜的新偏好。获得的结果有助于阐明miR在正常和患病视网膜中的功能。调节视网膜miR的表达可能代表未来针对RP等视网膜病变的治疗策略。
