VRC: Develop regenerative therapies for neurological vision loss

摘要 我们建议促进损伤视神经或视束的远距离轴突再生和视神经损伤的恢复 成体哺乳动物增强固有生长能力和生长锥动力学的视觉功能 神经元。我们将研究是否抑制let-7和/或上调其在视网膜中的抑制因子LIN28和Lin41 细胞促进视神经损伤的成年哺乳动物的强健轴突再生和功能恢复。我们 还将研究上调细胞骨架TACC3蛋白是否通过以下方式刺激显著的轴突再生 直接瞄准生长锥体。随着年龄的增长，中枢神经系统神经元失去再生轴突的能力，这限制了 损伤后功能恢复。目前已发现许多控制成熟期生长能力的基因。 神经元，但还没有一个转化为临床使用。最好的目标可能是那些有潜力的人 同时影响多个基因。其中，let-7 miRNA似乎对调节年龄很重要。 轴突再生的依赖性衰退。我们建议通过以下方式增强成熟神经元的生长能力 靶向LIN28/let-7/lin41通路。因为中枢神经切断后营养不良的生长锥体有助于 轴突再生失败，我们还建议通过上调细胞骨架生长动力学来增强细胞骨架生长动力学。 TACC3基因。我们假设let-7通路调节哺乳动物的轴突再生，并且 靶向该途径和细胞骨架TACC3基因可刺激强健的轴突再生和功能 视觉通路的恢复。使用PI实验室开发的新型AAV载体，我们将确定 抑制LET-7和/或上调视网膜细胞LIN28、LIN41或TACC3是否促进强健的轴突 视神经或视束损伤成年啮齿动物的再生和功能恢复。目标1建议研究 无论是单独的玻璃体内注射还是LET-7抑制剂LIN28或lin41的联合病毒载体 促进成年小鼠视神经轴突再生、视网膜神经节细胞存活和功能恢复。在AIM 2，我们将使用我们的AAV载体来研究上调TACC3是否刺激戏剧性轴突再生 同时针对let-7和TACC3信号的联合疗法是否能产生更好的轴突再生和 视神经轴突损伤的成年啮齿动物的功能恢复比任何一个单独的方法都要好。使用我们独特的 病毒载体不仅有可能为细胞生长的分子控制提供重要的新见解 成熟的中枢神经系统神经元，而且还开发实用和有效的策略，以促进轴突再生和 哺乳动物的功能恢复。我们使用组合策略来针对两个体细胞神经元的实验 程序和生长锥细胞骨架动力学应该刺激进一步的轴突再生和功能 恢复。因此，我们期待在成年哺乳动物身上发现非常有希望的再生策略。我们的 病毒载体在损伤后给予，可应用于多个轴突束，并易于翻译 进入临床试验。该项目的成功可能会扭转视功能障碍，提高视功能的质量 改善许多患者的生活，减轻患者、家庭和公众的经济负担。

Abstract We propose to promote long-distance axon regeneration of injured optic nerve or tract and recovery of visual function in adult mammals by enhancing intrinsic growth capacity and growth cone dynamics of mature neurons. We will study whether inhibiting let-7 and/or upregulating its suppressors lin28 and lin41 in retinal cells promotes robust axon regeneration and functional recovery in adult mammals with optic axon injury. We will also study whether upregulating cytoskeletal TACC3 protein stimulates dramatic axon regeneration by targeting growth cones directly. CNS neurons lose the ability to regenerate axons with age, and this limits functional recovery after injury. Many genes have been identified to control the growth ability of mature neurons, but none have been translated to clinical use. The best targets are probably those with the potential to impact multiple genes simultaneously. Among them, let-7 miRNA seems important for regulating age- dependent decline in axon regeneration. We propose to enhance the growth capacity of mature neurons by targeting the lin28/let-7/lin41 pathway. Because dystrophic growth cones in axotomized CNS contribute to axon regeneration failure, we also propose to enhance cytoskeletal growth dynamics by upregulating the TACC3 gene. We hypothesize that the let-7 pathway regulates axon regeneration in mammalians and that targeting this pathway plus the cytoskeletal TACC3 gene stimulates robust axon regeneration and functional recovery of visual pathways. Using the novel AAV vectors developed in the PI’s lab, we will determine whether inhibiting let-7 and/or upregulating lin28, lin41, or TACC3 in retinal cells promotes robust axon regeneration and functional recovery in adult rodents with optic nerve or tract injury. Aim 1 proposes to study whether intravitreal injections of the individual or combined viral vectors for let-7 inhibitor, lin28, or lin41 enhance optic axon regeneration, retinal ganglion cells survival, and functional recovery in adult mice. In Aim 2, we will use our AAV vectors to study whether upregulating TACC3 stimulates dramatic axon regeneration and whether combination therapies targeting both let-7 and TACC3 signals yield better axon regeneration and functional recovery in adult rodents with optic axon injury than either individual approach. Use of our unique viral vectors has the potential not only to provide important new insights into the molecular control of growth in mature CNS neurons, but also to develop practical and effective strategies to promote axon regeneration and functional recovery in mammals. Our experiments with combined strategies to target both somatic neuronal program and growth cone cytoskeletal dynamics should stimulate further axon regeneration and functional recovery. We thus anticipate identifying extremely promising regenerative strategies in adult mammals. Our viral vectors, which are administered post-injury, can be applied to multiple axon tracts and readily translated into clinical trials. The success of this project may reverse the visual functional deficits, improve the quality of life in many patients, and reduce the financial burdens to patients, families, and the public.