Tang Xuyuan, Li Xiuyi, Zhang Dongyan, Han Wei
Department of Ophthalmology, the First Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, China.
Department of Ophthalmology, the Second Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, China.
Bioengineered. 2022 Apr;13(4):8240-8254. doi: 10.1080/21655979.2022.2049471.
Astragaloside-IV (AS-IV) (CHO) is a high-purity natural product extracted from , which has demonstrated biological activities. However, the effect of AS-IV on retinal pigment epithelial (RPE) cells in diabetic retinopathy (DR) remains unclear. In this study, high glucose (HG) was shown to promote ARPE-19 RPE cell death, increase the contents of reactive oxygen species (ROS) and oxidized glutathione (GSSG), and enhance lipid peroxidation density of mitochondrial membrane. In contrast, AS-IV decreased glutathione (GSH) content, mitochondria size and ridge. Addition of iron death inhibitor Ferrostatin-1 (Fer-1) to RPE cells decreased cell dead rate, thus indicating that HG-induced mitochondrial damage occurred due to ferroptosis. AS-IV alleviated HG-induced RPE cell damage. Furthermore, HG decreased levels of silent information regulator 1 (Sirt1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in the nucleus of RPE cells; AS-IV could alleviate these effects and increased expression of glutathione peroxidase 4 (GPX4), glutamate cysteine ligase (GCLM) and glutamate cysteine ligase catalytic subunit (GCLC), which are Nrf2 downstream genes. Mechanistically, AS-IV was shown to alleviate the effects of HG by increasing mir-138-5p expression in RPE cells and promoting expression of Sirt1 and Nrf2 in the nucleus. Transfection of mir-138-5p agonist inhibited the regulatory effects of AS-IV on Sirt1 and Nrf2, accompanied by decreased GPX4, GCLM and GCLC levels, and restoration of ferroptosis-related changes. Collectively, HG increased ferroptosis rate in RPE cells. In addition, AS-IV inhibited miR-138-5p expression, subsequently increasing Sirt1/Nrf2 activity and cellular antioxidant capacity to alleviate ferroptosis, resulting decreased cell death, which potentially inhibits the DR pathological process.
黄芪甲苷-IV（AS-IV）（CHO）是从黄芪中提取的高纯度天然产物，已显示出生物活性。然而，AS-IV对糖尿病视网膜病变（DR）中视网膜色素上皮（RPE）细胞的作用仍不清楚。在本研究中，高糖（HG）被证明可促进ARPE-19 RPE细胞死亡，增加活性氧（ROS）和氧化型谷胱甘肽（GSSG）的含量，并增强线粒体膜的脂质过氧化密度。相比之下，AS-IV降低了谷胱甘肽（GSH）含量、线粒体大小和嵴。向RPE细胞中添加铁死亡抑制剂Ferrostatin-1（Fer-1）可降低细胞死亡率，因此表明HG诱导的线粒体损伤是由于铁死亡所致。AS-IV减轻了HG诱导的RPE细胞损伤。此外，HG降低了RPE细胞核中沉默信息调节因子1（Sirt1）和核因子（红细胞衍生2）样2（Nrf2）的水平；AS-IV可减轻这些影响，并增加Nrf2下游基因谷胱甘肽过氧化物酶4（GPX4）、谷氨酸半胱氨酸连接酶（GCLM）和谷氨酸半胱氨酸连接酶催化亚基（GCLC）的表达。机制上，AS-IV被证明可通过增加RPE细胞中mir-138-5p的表达并促进细胞核中Sirt1和Nrf2的表达来减轻HG的影响。mir-138-5p激动剂的转染抑制了AS-IV对Sirt1和Nrf2的调节作用，同时降低了GPX4、GCLM和GCLC的水平，并恢复了铁死亡相关的变化。总体而言，HG增加了RPE细胞中的铁死亡率。此外，AS-IV抑制miR-138-5p的表达，随后增加Sirt1/Nrf2活性和细胞抗氧化能力以减轻铁死亡，从而减少细胞死亡，这可能抑制DR的病理过程。
