State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060, China.
Electrophysiology Laboratory, Department of Ophthalmology, University Hospitals, Case Western Reserve University, Cleveland, OH 44101, USA.
Cells. 2020 Nov 13;9(11):2468. doi: 10.3390/cells9112468.
Retinal degenerative disorders (RDs) are the main cause of blindness without curable treatment. Our previous studies have demonstrated that human-induced pluripotent stem cells can differentiate into retinal organoids with all subtypes of retina, which provides huge promise for treating these diseases. Before these methods can be realized, RD animal models are required to evaluate the safety and efficacy of stem cell therapy and to develop the surgical tools and procedures for cell transplantation in patients. This study involved the development of a monkey model of RD with controllable lesion sites, which can be rapidly prepared for the study of preclinical stem cell therapy among other applications.
Sodium nitroprusside (SNP) in three doses was delivered into the monkey eye by subretinal injection (SI), and normal saline was applied as control. Structural and functional changes of the retinas were evaluated via multimodal imaging techniques and multifocal electroretinography (mfERG) before and after the treatment. Histological examination was performed to identify the target layer of the affected retina. The health status of monkeys was monitored during the experiment.
Well-defined lesions with various degrees of retinal degeneration were induced at the posterior pole of retina as early as 7 days after SNP SI. The damage of SNP was dose dependent. In general, 0.05 mM SNP caused mild structural changes in the retina; 0.1 mM SNP led to the loss of outer retinal layers, including the outer plexiform layer (OPL), outer nuclear layer (ONL), and retinal pigment epithelium (RPE); while 0.2 mM SNP impacted the entire layer of the retina and choroid. MfERG showed reduced amplitude in the damaged region. The structural and functional damages were not recovered at 7-month follow-up.
A rapidly induced lesion site-controllable retinal degeneration monkey model was established by the subretinal administration of SNP, of which the optimal dose is 0.1 mM. This monkey model mimics the histological changes of advanced RDs and provides a valuable platform for preclinical assessment of stem cell therapy for RDs.
视网膜退行性疾病（RDs）是目前尚无治愈方法的致盲的主要原因。我们之前的研究表明，人类诱导多能干细胞可以分化为具有所有视网膜亚型的视网膜类器官，这为治疗这些疾病提供了巨大的希望。在这些方法能够实现之前，需要建立 RD 动物模型来评估干细胞治疗的安全性和有效性，并开发用于患者细胞移植的手术工具和程序。本研究建立了一种具有可控病变部位的猴 RD 模型，该模型可快速用于临床前干细胞治疗的研究以及其他应用。
通过视网膜下注射（SI）将三种剂量的硝普钠（SNP）递送至猴眼内，并用生理盐水作为对照。在治疗前后，通过多模态成像技术和多焦视网膜电图（mfERG）评估视网膜的结构和功能变化。进行组织学检查以确定受影响视网膜的靶层。在实验过程中监测猴子的健康状况。
在 SNP SI 后 7 天，视网膜后极即可诱导出具有不同程度视网膜退行性变的明确病变。SNP 的损伤具有剂量依赖性。通常，0.05 mM SNP 导致视网膜结构发生轻度变化；0.1 mM SNP 导致外视网膜层（包括外丛状层[OPL]、外核层[ONL]和视网膜色素上皮[RPE]）丧失；而 0.2 mM SNP 则影响整个视网膜和脉络膜。mfERG 显示受损区域的振幅降低。在 7 个月的随访中，结构和功能损伤未恢复。
通过视网膜下给予 SNP 建立了一种快速诱导病变部位可控的视网膜退行性变猴模型，其最佳剂量为 0.1 mM。该猴模型模拟了晚期 RDs 的组织学变化，为 RDs 的临床前干细胞治疗评估提供了有价值的平台。
