To assess the engraftment of hESC-derived photoreceptors and their ability to restore vision in early and advanced stages of Retinitis Pigmentosa.

评估 hESC 来源的光感受器的植入及其在色素性视网膜炎早期和晚期恢复视力的能力。

基本信息

批准号：
MR/X001687/1
负责人：
Majlinda Lako
金额：
$ 136.17万
依托单位：
Newcastle University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=MR%2FX001687%2F1
关键词：
assess engraftment hESC derived photoreceptors

项目摘要

The retina is an extension of the central nervous system that lines the back of the eye, transmitting information from our visual world to the brain via the optic nerve. One of the important roles of the retina is to convert light into electrical signals, a process called phototransduction. These electrical signals are subsequently transmitted across retinal networks, eventually generating impulses in the optic nerve that connects the eye to the brain. Once these impulses reach central visual brain areas, they lead to visual perception. The cells responsible for phototransduction are the photoreceptors, the rods (responsible for vision in dim light conditions) and the cones (responsible for colour vision in bright light conditions and for our ability to see sharp details). One of the main causes of blindness is rod/cone malfunction, often due to genetic mutations (hereditary photoreceptor dystrophies). When these cells do not function properly, they gradually degenerate, leading to partial or total and irreversible blindness. There are currently no available preventative treatments or new therapeutic interventions that can successfully hinder disease progression or offer long-term promising outlook for patients suffering from these devastating conditions. Retinitis pigmentosa (RP) is a common form of hereditary photoreceptor dystrophy associated with progressive rod degeneration of the mid-peripheral retina, leading to night blindness and loss of visual acuity. At later stages of the disease, cones degenerate as well, resulting in complete blindness at final disease stages. Therefore, there is a pressing need to develop novel approaches either for photoreceptor replacement or for reactivation of dysfunctional surviving photoreceptor by gene therapy (if performed at early stages of the disease).In our group, we develop artificial retinas (organoids) derived from human pluripotent stem cells (hPSCs). We isolate photoreceptors from these organoids and inject them in retinas with photoreceptor dystrophies, with the goal to achieve integration of these new healthy photoreceptors into the host retina, eventually restoring visual function. We have successfully achieved these goals using a cone-enriched population of photoreceptor precursors in a mouse model of RP, resulting in partial restoration of visual function assessed by behavioural and electrophysiological testing. However, given the prevalence of rod degeneration in RP, our hypothesis is that transplantation of hPSCs-derived rods at early stages may lead to improved rod integration and function, while also protecting cones from degenerating at later stages. In addition, we suggest that a combination of rod and cone transplantation may achieve optimal results at more advanced stages of retinal degeneration.Here we propose to test this hypothesis in a mouse model of RP. We will develop new hPSC lines, which will enable enrichment of cone and rod precursors, each one carrying a genetically encoded fluorescent marker of a different colour for easier identification once engrafted in the host retina. In one set of experiments, we will inject rods alone at early degeneration stages, with the goal of improving their integration into the host retina and protecting cones from later degeneration. In another set of experiments, we will inject a mixed population of rod and cone precursors at later stages of degeneration, to see whether this approach protects cones from ensuing degeneration. Using all the tools we have developed to generate homogenous populations of cone and rod precursors from hPSCs, perform successful cell transplantation and assess vision restoration using behavioural and electrophysiological approaches, this project will provide fundamental knowledge to establish the optimal conditions necessary for successful large-scale engraftment of stem cell-derived healthy photoreceptors to restore sight in devastating photoreceptor dystrophies.

视网膜是中枢神经系统的延伸，位于眼睛后部，通过视神经将信息从我们的视觉世界传输到大脑。视网膜的重要作用之一是将光转换为电信号，这一过程称为光转导。这些电信号随后通过视网膜网络传输，最终在连接眼睛和大脑的视神经中产生脉冲。一旦这些冲动到达中枢视觉大脑区域，就会产生视觉感知。负责光转导的细胞是光感受器、视杆细胞（负责弱光条件下的视觉）和视锥细胞（负责强光条件下的色觉以及我们看到清晰细节的能力）。失明的主要原因之一是视杆细胞/视锥细胞功能障碍，通常是由于基因突变（遗传性感光细胞营养不良）造成的。当这些细胞不能正常工作时，它们会逐渐退化，导致部分或全部和不可逆转的失明。目前尚无可用的预防性治疗或新的治疗干预措施可以成功阻止疾病进展或为患有这些破坏性疾病的患者提供长期有希望的前景。色素性视网膜炎 (RP) 是遗传性感光细胞营养不良的一种常见形式，与中周边视网膜进行性杆状变性相关，导致夜盲症和视力丧失。在疾病的后期阶段，视锥细胞也会退化，导致疾病最终阶段完全失明。因此，迫切需要开发新的方法来替代光感受器或通过基因疗法重新激活功能失调的存活光感受器（如果在疾病的早期阶段进行）。在我们的小组中，我们开发了源自人类的人造视网膜（类器官）多能干细胞（hPSC）。我们从这些类器官中分离出光感受器，并将它们注射到患有光感受器营养不良的视网膜中，目标是将这些新的健康光感受器整合到宿主视网膜中，最终恢复视觉功能。我们在 RP 小鼠模型中使用富含视锥细胞的光感受器前体群体成功实现了这些目标，从而通过行为和电生理测试评估视觉功能的部分恢复。然而，考虑到 RP 中视杆细胞退化的普遍性，我们的假设是，在早期阶段移植 hPSC 衍生的视杆细胞可能会改善视杆细胞的整合和功能，同时还能保护视锥细胞在后期免受退化。此外，我们认为视杆细胞和视锥细胞移植的结合可能会在视网膜变性的更晚期阶段获得最佳结果。在这里，我们建议在 RP 小鼠模型中检验这一假设。我们将开发新的 hPSC 系，这将能够富集视锥细胞和视杆细胞前体，每个细胞都携带不同颜色的基因编码荧光标记，以便在植入宿主视网膜后更容易识别。在一组实验中，我们将在早期退化阶段单独注射视杆细胞，目的是改善它们与宿主视网膜的整合并保护视锥细胞免受后期退化。在另一组实验中，我们将在退化的后期注射视杆细胞和视锥细胞前体的混合群体，以观察这种方法是否可以保护视锥细胞免于随后的退化。利用我们开发的所有工具，从 hPSC 中产生同质的视锥细胞和视杆细胞前体群体，进行成功的细胞移植，并使用行为和电生理学方法评估视力恢复情况，该项目将提供基础知识，以建立成功大规模生产所需的最佳条件。植入干细胞衍生的健康光感受器，以在毁灭性的光感受器营养不良中恢复视力。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Incorporating microglia-like cells in human induced pluripotent stem cell-derived retinal organoids.

DOI：
10.1111/jcmm.17670
发表时间：
2023-02
期刊：
Journal of cellular and molecular medicine
影响因子：
5.3
作者：
通讯作者：

Pluripotent stem cell-derived models of retinal disease: Elucidating pathogenesis, evaluating novel treatments, and estimating toxicity

DOI：
10.1016/j.preteyeres.2024.101248
发表时间：
2024-03-20
期刊：
PROGRESS IN RETINAL AND EYE RESEARCH
影响因子：
17.8
作者：
Kurzawa-Akanbi，Marzena;Tzoumas，Nikolaos;Lako，Majlinda
通讯作者：
Lako，Majlinda

Bruch's Membrane: A Key Consideration with Complement-Based Therapies for Age-Related Macular Degeneration.

DOI：
10.3390/jcm12082870
发表时间：
2023-04-14
期刊：
JOURNAL OF CLINICAL MEDICINE
影响因子：
3.9
作者：
Hammadi, Sarah;Tzoumas, Nikolaos;Ferrara, Mariantonia;Meschede, Ingrid Porpino;Lo, Katharina;Harris, Claire;Lako, Majlinda;Steel, David H.
通讯作者：
Steel, David H.

Deciphering the spatio-temporal transcriptional and chromatin accessibility of human retinal organoid development at the single cell level

在单细胞水平上破译人类视网膜类器官发育的时空转录和染色质可及性