Department of Ophthalmology, General Hospital of Ningxia Medical University, Ningxia Hui Autonomous Region, 750004, Yinchuan, China.
BMC Ophthalmol. 2023 Jan 13;23(1):22. doi: 10.1186/s12886-022-02762-8.
The decrease of vitamin D plays a critical role in diabetes mellitus (DM)-induced oxidative stress and vascular endothelial injury. Therefore, we investigated the effect and mechanism of 25-hydroxyvitamin D3 (25 (OH) D3) on oxidative stress and ferroptosis induced by high glucose in human retinal microvascular endothelial cells (hRMVECs). And the objective of this paper was to propose a new strategy for the prevention and treatment of diabetic retinopathy (DR).
First, hRMVECs were transfected with mimics NC or miR-93. After that, cells were treated with 100 nM / 500 nM 25 (OH) D3 and then cultured in a high glucose (30 mM) environment. Subsequently, qRT-PCR was employed to detect the expression level of miR-93; CCK-8 for the proliferation of cells in each group; biochemical tests for the level of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), reduced glutathione (GSH) and ferrous ion (Fe); and Western blot for the expression of ferroptosis-related proteins glutathione peroxidase 4 (GPX4) and SLC7A11).
Under a high glucose environment, 25 (OH) D3 at 100 nM/500 nM could significantly promote the proliferation of hRMVECs, remarkably decrease the level of intracellular ROS/MDA, and up-regulate the level of GSH. Besides, 25 (OH) D3 greatly reduced Fe level in the cells while increased protein level of GPX4 and SLC7A11. Subsequently, we found that high glucose induced miR-93 expression, while 25 (OH) D3 markedly decreased high glucose-induced miR-93 overexpression. Furthermore, overexpression of miR-93 inhibited the functions of 25 (OH) D3 by activating ROS (ROS and MDA were up-regulated while GSH was down-regulated) and inducing Fe (Fe level was up-regulated while GPX4 and SLC7A11 level was down-regulated) in cells.
25 (OH) D3 may inhibit oxidative stress and ferroptosis in hRMVECs induced by high glucose via down-regulation of miR-93.
维生素 D 的减少在糖尿病（DM）诱导的氧化应激和血管内皮损伤中起着关键作用。因此，我们研究了 25-羟维生素 D3（25（OH）D3）对高糖诱导的人视网膜微血管内皮细胞（hRMVEC）氧化应激和铁死亡的作用及机制。本文旨在为糖尿病性视网膜病变（DR）的防治提供新策略。
首先，用 mimics NC 或 miR-93 转染 hRMVECs。然后，用 100 nM/500 nM 25（OH）D3 处理细胞，然后在高糖（30 mM）环境中培养。随后，qRT-PCR 检测 miR-93 的表达水平；CCK-8 检测各组细胞的增殖情况；生化试验检测细胞内活性氧（ROS）、丙二醛（MDA）、还原型谷胱甘肽（GSH）和亚铁离子（Fe）水平；Western blot 检测铁死亡相关蛋白谷胱甘肽过氧化物酶 4（GPX4）和溶质载体家族 7 成员 11（SLC7A11）的表达水平。
在高糖环境下，100 nM/500 nM 25（OH）D3 可显著促进 hRMVECs 的增殖，显著降低细胞内 ROS/MDA 水平，上调 GSH 水平。此外，25（OH）D3 降低细胞内 Fe 水平，增加 GPX4 和 SLC7A11 蛋白水平。随后，我们发现高糖诱导 miR-93 表达，而 25（OH）D3 显著降低高糖诱导的 miR-93 过表达。此外，miR-93 的过表达通过激活 ROS（ROS 和 MDA 升高，GSH 降低）和诱导 Fe（Fe 水平升高，GPX4 和 SLC7A11 水平降低）来抑制 25（OH）D3 的作用。
25（OH）D3 可能通过下调 miR-93 抑制高糖诱导的 hRMVEC 氧化应激和铁死亡。
