Guangzhou Aier Eye Hospital, Aier Eye Hospital Group, Guangzhou, China.
Aier School of Ophthalmology, Central South University, Changsha, China.
Clin Exp Ophthalmol. 2020 Jul;48(5):682-688. doi: 10.1111/ceo.13751. Epub 2020 Mar 31.
Geographic atrophy (GA) is a late-stage symptom of an age-related macular degeneration (AMD), characterized by the loss of retinal pigment epithelial (RPE) cells and photoreceptor functions. Despite being a major cause of blindness in individuals of 65 years of age and older, some forms of AMD, including GA, still lack targeted treatment. Our previous study demonstrated that mini-αA peptide, which contains the functional site of αA-crystallin, protected RPE cells from NaIO -induced apoptosis.
To further investigate the underlying mechanism, we applied next-generation sequencing analysis to identify miR-1246 as a putative mediator of mini-αA protective function. To investigate the role of miR-1246 in RPE cell apoptosis, a stable miR-1246-low-expression cell line was established by using miR-1246 inhibitor. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to investigate the proliferation of RPE cells, mRNA and miR-1246 expression were detected by the quantitative reverse transcriptase-polymerase chain reaction.
We have further identified caspase-3 and caspase-14 as molecular targets of miR-1246 involved in regulation of apoptosis in NaIO -incubated cells. Interestingly, disruption of miR-1246 expression enhanced anti-apoptotic effect of mini-αA on RPE cells during oxidative stress.
Our results provide a mechanistic basis for evaluation of miR-1246 as a new candidate target for the clinical treatment of AMD.
地理萎缩(GA)是年龄相关性黄斑变性(AMD)的晚期症状,其特征是视网膜色素上皮(RPE)细胞和光感受器功能丧失。尽管 GA 是 65 岁及以上人群失明的主要原因之一,但包括 GA 在内的某些形式的 AMD 仍然缺乏靶向治疗。我们之前的研究表明,含有αA 晶体蛋白功能位点的 mini-αA 肽可保护 RPE 细胞免受 NaIO 诱导的细胞凋亡。
为了进一步研究其潜在机制,我们应用下一代测序分析鉴定出 miR-1246 是 mini-αA 保护功能的一个潜在介质。为了研究 miR-1246 在 RPE 细胞凋亡中的作用,我们使用 miR-1246 抑制剂建立了稳定的 miR-1246 低表达细胞系。采用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐法检测 RPE 细胞的增殖,采用定量逆转录聚合酶链反应检测 mRNA 和 miR-1246 的表达。
我们进一步鉴定出 caspase-3 和 caspase-14 是 miR-1246 的分子靶点,参与调节 NaIO 孵育细胞中的细胞凋亡。有趣的是,miR-1246 表达的破坏增强了 mini-αA 在氧化应激下对 RPE 细胞的抗凋亡作用。
我们的研究结果为评估 miR-1246 作为 AMD 临床治疗的新候选靶点提供了机制基础。