TISSUE ENGINEERED CELL TRANSPLANTATION FOR GLAUCOMA AND OPTIC NEUROPATHIES

项目摘要/摘要 在这里，我们建议开发一种生物工程支架，用于内视网膜，能够用作 既是这种组织的模型，也是细胞移植的工具。神经视网膜，像大脑的其他部分一样 中枢神经系统(CNS)在损伤或疾病引起的细胞死亡后不能再生。至 克服这种缺乏再生修复的情况，在光感受器疾病中，细胞替代疗法已经 有人试图这样做。在这些研究中，注入的细胞能够迁移到正确的视网膜板层，形成 动物模型中的突触和功能1，2但这种技术是否可以用于视网膜疾病 神经节细胞(RGC)的轴突必须通过病变的视神经抑制环境再生 胆子大？最近发现了促进视神经和中枢神经系统轴突再生的分子机制， 例如PTEN/SOCS3或KLF4缺失，3-6结合我们的研究显示移植的RGC延长 局部突起并在内丛状层(IPL)形成突触，7提示移植治疗 对于RGC来说，可能还是可能的。然而，迄今为止的数据表明，移植的细胞在很大程度上无法 引导轴突朝向视神经头，可能是由于视网膜引导的发育变化 分子。8，9最近，我们开发了一种可生物降解的径向电纺支架(Res)细胞输送 能够径向引导RGC轴突，与视网膜神经纤维层的方向相匹配的车辆 10然而，种植在RE上的RGC是双向生长的，而不是轴突生长 偏向中心，就像在天然组织中一样。此外，目前尚不清楚移植的细胞是否会 能够将它们的树突从细胞输送工具中延伸出来，与受损的视网膜形成突触。 在这项研究中，我们将进一步开发我们的细胞输送支架，固定在 一旦移植，发育使轴突向支架中心和视神经头极化生长。 此外，我们还将RES与由ECM基质组成的水凝胶组成的显影剂相结合 IPL，以刺激移植的RGC树突向视网膜外植体延伸。利用这些外植体 模型，我们将评估移植细胞的功能性突触连接通过染色和 光响应的传播。最后，使用修改后的细胞通过受损的视神经重新生长，我们将 研究移植细胞中的轴突进入视神经的能力。这些研究将导致 制造具有正确图案的神经节细胞层和水凝胶的视网膜细胞输送装置 系统进行了优化，以刺激移植细胞的整合。综上所述，这项提议将是一个 朝着为青光眼和其他视障患者恢复视力的长期目标迈出重要的一步 神经病。

PROJECT SUMMARY/ABSTRACT Here we propose to develop a bio-engineered scaffold for the inner retina capable of being used as both a model for this tissue and as a tool for cell transplantation. The neural retina, like other parts of the central nervous system (CNS), fails to regenerate following cell death associated with injury or diseases. To overcome this lack of regenerative repair, in diseases of the photoreceptors, cell replacement therapies have been attempted. In these studies, injected cells are able to migrate into the correct lamina of the retina, form synapses and function in animal models.1, 2 But can such a technique be used with diseases of the retinal ganglion cells (RGCs) whose axons must regrow through the inhibitory environment of the diseased optic nerve? The recent discovery of molecular mechanisms that promote optic nerve and CNS axon regeneration, such as PTEN/SOCS3 or KLF4 deletion,3-6 combined with our studies showing transplanted RGCs extend processes locally and form synapses in the inner plexiform layer (IPL),7 suggest that a transplantation therapy may yet be possible for RGCs. However, data thus far suggest that transplanted cells are largely unable to direct their axons towards the optic nerve head, perhaps due to developmental changes in retinal guidance molecules.8, 9 Recently, we have developed a biodegradable radial electrospun scaffold (rES) cell delivery vehicle capable of directing RGC axons radially, matching the orientation of the retinal nerve fiber layer (NFL).10 However the RGCs seeded on the rES grow in both directions rather than having their axon growth polarized towards the center as it is in the native tissue. In addition, it is not known if the transplanted cells will be capable of extending their dendrites off of the cell delivery vehicle to form synapses with the injured retina. In this study, we will further develop our cell delivery scaffold, immobilizing neurotrophic factors found during development to polarize axon growth towards the scaffold center and the optic nerve head once transplanted. In addition, we will combine the rES with a hydrogel composed of ECM matrix components of the developing IPL in order to stimulate the transplanted RGC dendrites extension to retinal explants. Using these explant models, we will evaluate the transplanted cells for functional synaptic connections through staining and the propagation of light responses. Finally, using cells modified for regrowth through an injured optic nerve, we will investigate the ability of axons from transplanted cells to enter the optic nerve. These studies will lead to the creation of a retinal cell delivery device with the correct patterning of the ganglion cell layer and a hydrogel system optimized to stimulate the integration of the transplanted cells. Taken together, this proposal will be an important step towards our long term goal of restoring vision to those suffering from glaucoma and other optic neuropathies.