Melanopsin-based form vision in photoreceptor disease

光感受器疾病中基于黑视蛋白的形式视觉

• 批准号: 6900534
• 负责人: Michael A Sandberg
• 金额: $ 16.95万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6900534
• 关键词: action potentials; calcium channel blockers; evoked potentials; form /pattern perception; ganglion cell; gene expression; gene therapy; glutamates; green fluorescent proteins; histochemistry /cytochemistry; laboratory mouse; light microscopy; microelectrodes; nonhuman therapy evaluation; retina degeneration; rhodopsin; transfection; visual fields; visual perception; visual photoreceptor; visual photosensitivity

DESCRIPTION (provided by applicant): The long-term objective of this program is to use melanopsin gene therapy to restore useful form vision and visual field to patients blind due to photoreceptor degeneration. Melanopsin is an invertebrate-like opsin present in rare, intrinsically-photosensitive, large-field ganglion cells of the mammalian retina not involved in the processing of spatial information. This pilot study is intended to demonstrate proof of principle with the following sequence of specific aims: (1) to express melanopsin in typical, small-field ganglion cells of mice with advanced photoreceptor degeneration, (2) to show that these modified ganglion cells have become intrinsically light-sensitive and to describe their stimulus-response characteristics, and (3) to show that melanopsin treatment improves the pattern discrimination of these mice. We will inject a recombinant adeno-associated virus (AAV) carrying the melanopsin gene and the GFP reporter gene (as a marker) into the vitreous of one eye of 1-month-old retinal degeneration (rd/rd) mice and use light microscopy to assess the level, extent, and persistence of transgene expression in ganglion cells. We will then use a microelectrode array on the retinal surface to record extracellular action potentials from ganglion cells of melanopsin-treated versus untreated eyes to demonstrate the photosensitivity and response characteristics of the transduced cells. We will then infer the visual acuity for melanopsin-treated versus untreated eyes by recording monocular pattern visually evoked potentials in response to an alternating stripe pattern of varying spatial frequency. If this pilot program is successful, then transfection of the melanopsin gene into typical, small-field ganglion cells of patients with hand-motions or worse vision and markedly constricted fields due to photoreceptor degeneration could be a future consideration to improve their visual acuity to ~20/100 and widen their visual field to enhance mobility. Restoration of useful form vision to some 4,000 such patients in the United States would facilitate their functioning independently in society and improve the long-term outlook of approximately 100,000 patients with generalized photoreceptor degeneration in this country who have not yet become blind.

描述（申请人提供）：该项目的长期目标是利用黑视蛋白基因疗法，使因光感受器变性而失明的患者恢复有用的视力和视野。黑视蛋白是一种类似无脊椎动物的视蛋白，存在于哺乳动物视网膜的稀有、本质光敏、大视场神经节细胞中，不参与空间信息的处理。这项初步研究旨在证明具有以下具体目标序列的原理证明：(1) 在患有晚期感光器变性的小鼠的典型小视场神经节细胞中表达黑视蛋白，(2) 证明这些修饰的神经节细胞具有变得本质上对光敏感并描述它们的刺激响应特征，以及（3）表明黑视蛋白治疗改善了这些小鼠的模式辨别能力。我们将携带黑视蛋白基因和GFP报告基因（作为标记）的重组腺相关病毒（AAV）注射到1个月大视网膜变性（rd/rd）小鼠一只眼睛的玻璃体中，并使用光学显微镜观察评估神经节细胞中转基因表达的水平、程度和持久性。然后，我们将使用视网膜表面上的微电极阵列记录黑视蛋白处理与未处理眼睛的神经节细胞的细胞外动作电位，以证明转导细胞的光敏性和响应特征。然后，我们将通过记录响应于不同空间频率的交替条纹图案的单眼图案视觉诱发电位来推断黑视素处理与未处理的眼睛的视敏度。如果该试点计划成功，那么将黑视蛋白基因转染到手部运动或视力较差且由于感光器变性而视野明显收缩的患者的典型小视场神经节细胞中可能是未来考虑将其视力提高到〜 20/100 并拓宽视野以增强机动性。让美国约 4,000 名此类患者恢复有用的视力，将有助于他们在社会中独立运作，并改善该国约 100,000 名尚未失明的全身性感光器变性患者的长期前景。