Gene Therapy for Retinal Detachment

描述(申请人提供)：视网膜脱离并随后丧失视力是与许多眼部疾病相关的主要临床问题，包括增殖性玻璃体视网膜病变(PVR)和增殖性糖尿病视网膜病变(PDR)。手术是目前唯一可用的治疗方法，但纤维视网膜前膜形成和视网膜脱离的复发率很高。在PVR和PDR形成的视网膜前膜中，含有平滑肌(SM)α-肌动蛋白的肌成纤维细胞是一种主要的细胞类型，正是这些细胞负责产生导致视网膜脱离的力。这项研究的长期目标是开发一种基于基因治疗的方法，靶向并阻断肌成纤维细胞的收缩。该项目的第一个目标是开发一种肌成纤维细胞特异性启动子。最近的研究表明，SMα-肌动蛋白在肌成纤维细胞和平滑肌细胞中的表达调控是不同的，这些研究已经开始确定SMα-肌动蛋白启动子中可能导致这些差异的调控元件。因此，第一个特定的目标是确定SMα-肌动蛋白启动子中的调控元件，这些元件是视网膜前膜中的肌成纤维细胞所特有的。为了达到这个目的，我们将使用含有SMα-肌动蛋白启动子/LacZ转基因的转基因小鼠，在转基因小鼠中，特定的调控元件已被删除或突变。这些小鼠将与转基因小鼠模型交配，在转基因小鼠模型中，含有肌成纤维细胞的视网膜前膜形成并收缩，随后发生视网膜脱离。我们长期目标的第二部分是能够阻止视网膜前膜中肌成纤维细胞的收缩。肌成纤维细胞中SMα-肌动蛋白的表达与这些细胞产生大量收缩力量的能力有关。因此，第二个具体目标是确定敲除SMα-肌动蛋白基因是否会减少或抑制视网膜脱离。具体地说，我们将确定对照组和SMα-肌动蛋白缺失小鼠视网膜脱离发生的时间长度。这些研究将为开发一种基于基因治疗的方法提供基础，该方法可以特异性地靶向视网膜前膜中的肌成纤维细胞，并阻断其收缩力量的产生，从而阻止视网膜前膜收缩和视网膜脱离。

DESCRIPTION (provided by applicant): Retinal detachment with subsequent loss of vision is a major clinical problem associated with a number of ocular diseases, including proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Surgery, the only treatment currently available, has a high rate of recurrence of fibrous epiretinal membrane formation and retinal detachment. Smooth muscle (SM) alpha-actin containing myofibroblasts are a major cell type present in the epiretinal membranes that form in PVR and PDR and it is these cells that are responsible for generation of force leading to retinal detachment. The long-term goal of this research is to develop a gene therapy-based approach that targets and blocks the contraction of the myofibroblast. The first objective of this project is to develop a myofibroblast-specific promoter. Recent studies have suggested that the regulation of SM alpha-actin expression is different in myofibroblasts and smooth muscle cells and these studies have begun to identify regulatory elements in the promoter bf SM alpha-actin that might be responsible for these differences. Therefore, the first specific aim is to identify regulatory elements within the SM alpha-actin promoter that are specific to myofibroblasts in epiretinal membranes. To address this aim we will use transgenic mice containing a SM alpha-actin promoter/LacZ transgene in which specific regulatory elements have been deleted or mutated. These mice will be mated with a transgenic mouse model in which an epiretinal membrane containing myofibroblasts forms and contracts, with subsequent retinal detachment. The second part of our long-term goal is to be able to block the contraction of myofibroblasts in the epiretinal membranes. The expression of SM alpha-actin in myofibroblasts is functionally related to the ability of these cells to generate large amounts of contractile force. Therefore, the second specific aim is to determine whether knocking out the SM alpha-actin gene will decrease or inhibit retinal detachment. Specifically we will determine the length of time it takes for retinal detachment to occur in control and SM alpha-actin-null mice. These studies will provide the basis for developing a gene therapy-based approach that can specifically target myofibroblasts in epiretinal membranes and block their generation of contractile force thereby blocking epiretinal membrane contraction and retinal detachment.