Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, NE1 3BZ, UK.
Microscopy Centre and Department of Applied Clinical Sciences and Biotechnology, University of L'Aquila, L'aquila 67100, Italy.
Hum Mol Genet. 2023 May 5;32(10):1698-1710. doi: 10.1093/hmg/ddad007.
Age-related macular degeneration (AMD) is the most prevalent cause of blindness in the developed world. Vision loss in the advanced stages of the disease is caused by atrophy of retinal photoreceptors, overlying retinal pigment epithelium (RPE) and choroidal endothelial cells. The molecular events that underline the development of these cell types from in utero to adult as well as the progression to intermediate and advanced stages AMD are not yet fully understood. We performed single-cell RNA-sequencing (RNA-Seq) of human fetal and adult RPE-choroidal tissues, profiling in detail all the cell types and elucidating cell type-specific proliferation, differentiation and immunomodulation events that occur up to midgestation. Our data demonstrate that progression from the fetal to adult state is characterized by an increase in expression of genes involved in the oxidative stress response and detoxification from heavy metals, suggesting a better defence against oxidative stress in the adult RPE-choroid tissue. Single-cell comparative transcriptional analysis between a patient with intermediate AMD and an unaffected subject revealed a reduction in the number of RPE cells and melanocytes in the macular region of the AMD patient. Together these findings may suggest a macular loss of RPE cells and melanocytes in the AMD patients, but given the complex processing of tissues required for single-cell RNA-Seq that is prone to technical artefacts, these findings need to be validated by additional techniques in a larger number of AMD patients and controls.
年龄相关性黄斑变性（AMD）是发达国家最常见的致盲原因。疾病晚期的视力丧失是由视网膜光感受器、覆盖的视网膜色素上皮（RPE）和脉络膜内皮细胞的萎缩引起的。从胚胎到成年以及从中期到晚期 AMD 发展过程中这些细胞类型的发育以及进展的分子事件尚不完全清楚。我们对人胎儿和成人 RPE-脉络膜组织进行了单细胞 RNA 测序（RNA-Seq），详细分析了所有细胞类型，并阐明了从中期妊娠到晚期妊娠发生的细胞特异性增殖、分化和免疫调节事件。我们的数据表明，从胎儿到成年状态的进展以与氧化应激反应和重金属解毒相关的基因表达增加为特征，表明成年 RPE-脉络膜组织对氧化应激具有更好的防御能力。中间型 AMD 患者和未受影响个体之间的单细胞比较转录分析显示，AMD 患者黄斑区的 RPE 细胞和黑素细胞数量减少。这些发现共同表明 AMD 患者的 RPE 细胞和黑素细胞在黄斑区丢失，但由于单细胞 RNA-Seq 所需的组织复杂处理容易出现技术伪影，这些发现需要在更多 AMD 患者和对照组中通过其他技术进行验证。
