Inhibiting microRNA-144 potentiates Nrf2-dependent antioxidant signaling in RPE and protects against oxidative stress-induced outer retinal degeneration
Inhibiting microRNA-144 potentiates Nrf2-dependent antioxidant signaling in RPE and protects against oxidative stress-induced outer retinal degeneration
复制标题
抑制microRNA-144增强RPE中Nrf 2依赖性抗氧化信号传导并保护免受氧化应激诱导的外视网膜变性
DOI：
10.1016/j.redox.2019.101336
复制
发表时间：
2020-01-01
期刊：
影响因子：
11.4
通讯作者：
Martin, Pamela M.
中科院分区：
文献类型：
--
作者：
Jadeja, Ravirajsinh N.;Jones, Malita A.;Martin, Pamela M.
视网膜色素上皮(RPE)持续暴露在高水平的促氧化剂和炎症刺激下。因此，在正常情况下，RPE细胞中的抗氧化机制是整个身体最有效的机制之一。然而，抗氧化防御机制经常受到衰老和/或退行性疾病过程的负面影响，使RPE容易受到损害，从而导致视网膜功能障碍。因此，更好地了解RPE中控制抗氧化反应的机制是至关重要的。在这里，我们评估了氧化还原敏感的microRNA miR-144在调节人和鼠RPE中的抗氧化信号中的作用。在培养的人RPE中，miR-144-3p和miR-144-5p的表达在促氧化剂刺激下上调。同样，使用靶向miR模拟物过表达miR-144-3p和-5p与Nrf2及其下游抗氧化靶基因(NQO1和GCLC)的表达减少、谷胱甘肽水平降低和RPE细胞死亡增加相关。或者，当用反交配子抑制miR-144-3p和miR-144-5p的表达时，对上述情况有一定的保护作用。表达分析显示，miR-144-3p在不同物种中的表达具有更高的保守性，此外，与5p序列中只有一个结合位点相比，3p序列中存在两个潜在的Nrf2结合位点。因此，我们评估了miR-144-3p在使用碘酸钠(SI)产生强大的促氧化环境的小鼠视网膜中表达的影响。在SI小鼠视网膜下注射miR-144-3p antagomir可保护视网膜的完整性和功能，减少氧化应激，限制细胞凋亡，增强抗氧化基因的表达。总而言之，本工作确立了miR-144作为预防和治疗以氧化应激为主且RPE受到显著影响的退行性视网膜疾病(例如，老年性黄斑变性和糖尿病视网膜病变)的潜在靶点。
The retinal pigment epithelium (RPE) is consistently exposed to high levels of pro-oxidant and inflammatory stimuli. As such, under normal conditions the antioxidant machinery in the RPE cell is one of the most efficient in the entire body. However, antioxidant defense mechanisms are often impacted negatively by the process of aging and/or degenerative disease leaving RPE susceptible to damage which contributes to retinal dysfunction. Thus, understanding better the mechanisms governing antioxidant responses in RPE is critically important. Here, we evaluated the role of the redox sensitive microRNA miR-144 in regulation of antioxidant signaling in human and mouse RPE. In cultured human RPE, miR-144-3p and miR-144-5p expression was upregulated in response to pro-oxidant stimuli. Likewise, overexpression of miR-144-3p and -5p using targeted miR mimics was associated with reduced expression of Nrf2 and downstream antioxidant target genes (NQO1 and GCLC), reduced levels of glutathione and increased RPE cell death. Alternately, some protection was conferred against the above when miR-144-3p and miR-144-5p expression was suppressed using antagomirs. Expression analyses revealed a higher conservation of miR-144-3p expression across species and additionally, the presence of two potential Nrf2 binding sites in the 3p sequence compared to only one in the 5p sequence. Thus, we evaluated the impact of miR-144-3p expression in the retinas of mice in which a robust pro-oxidant environment was generated using sodium iodate (SI). Subretinal injection of miR-144-3p antagomir in SI mice preserved retinal integrity and function, decreased oxidative stress, limited apoptosis and enhanced antioxidant gene expression. Collectively, the present work establishes miR-144 as a potential target for preventing and treating degenerative retinal diseases in which oxidative stress is paramount and RPE is prominently affected (e.g., age-related macular degeneration and diabetic retinopathy).