Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Maumenee B-110, Baltimore, MD 21287, USA.
Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Maumenee B-110, Baltimore, MD 21287, USA; Departments of Molecular Biology and Genetics, Neuroscience, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
Stem Cell Reports. 2021 Jan 12;16(1):149-167. doi: 10.1016/j.stemcr.2020.12.001. Epub 2020 Dec 30.
Retinal ganglion cell (RGC) replacement holds potential for restoring vision lost to optic neuropathy. Transplanted RGCs must undergo neuroretinal integration to receive afferent visual signals for processing and efferent transmission. To date, retinal integration following RGC transplantation has been limited. We sought to overcome key barriers to transplanted human stem cell-derived RGC integration. Following co-culture ex vivo on organotypic mouse retinal explants, human RGCs cluster and extend bundled neurites that remain superficial to the neuroretina, hindering afferent synaptogenesis. To enhance integration, we increased the cellular permeability of the internal limiting membrane (ILM). Extracellular matrix digestion using proteolytic enzymes achieved ILM disruption while minimizing retinal toxicity and preserving glial reactivity. ILM disruption is associated with dispersion rather than clustering of co-cultured RGC bodies and neurites, and increased parenchymal neurite ingrowth. The ILM represents a significant obstacle to transplanted RGC connectivity and its circumvention may be necessary for functional RGC replacement.
视网膜神经节细胞 (RGC) 替代有望恢复因视神经病变而丧失的视力。移植的 RGC 必须进行神经视网膜整合，以接收用于处理和传出传输的传入视觉信号。迄今为止，RGC 移植后的视网膜整合受到限制。我们试图克服移植的人干细胞衍生的 RGC 整合的关键障碍。在器官型小鼠视网膜外植体上进行体外共培养后，人 RGC 会聚集并延伸捆绑的神经突，这些神经突仍然位于神经视网膜的浅层，阻碍传入的突触形成。为了增强整合，我们增加了内界膜 (ILM) 的细胞通透性。使用蛋白水解酶进行细胞外基质消化可破坏 ILM，同时最大限度地减少视网膜毒性并保持神经胶质反应性。ILM 的破坏与共培养的 RGC 体和神经突的分散而不是聚集有关，并增加了实质神经突的向内生长。ILM 是移植的 RGC 连接的一个重大障碍，其规避可能对于功能性 RGC 替代是必要的。
