Department of Anesthesiology, Tongji Hospital, Tongji University, Shanghai, China.
Immunopharmacol Immunotoxicol. 2021 Aug;43(4):478-486. doi: 10.1080/08923973.2021.1942901. Epub 2021 Jul 1.
To investigate effects of dexmedetomidine (DEX) on miR-205-5p/HMGB1 axis in cerebral ischemic/reperfusion (I/R) injury.
Both I/R rat model and hypoxia/reoxygenation (H/R) cell model using rat hippocampal neurons cells were established. miR-205-5p was overexpressed or inhibited by transfection of miR-205-5p mimics or inhibitor. HMGB1 was overexpressed by transfection overexpression plasmids (OE-HMGB1). TTC staining was used for measurement of infraction volume. Oxidative stress was evaluated by measurement of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) and inflammation was evaluated by measurement of IL-1β, IL-6 and TNF-α. Dual luciferase reporter assay was performed to confirm binding between miR-205-5p and HMGB1. The expression levels of miR-205-5p, and HMGB1 were measured using RT-qPCR. Western blotting was used to test the protein expression levels of HMGB1, nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase (GPx), glutathione reductase (GR), heme oxygenase 1 (HO-1) and catalase (CAT).
Treatment of DEX significantly reduced brain infraction volume, decreased Longa's neurological function score and inhibited oxidative stress and inflammation in brain tissues of I/R rats, which were all reversed by inhibition of miR-205-5p. Both treatment of DEX or overexpression of miR-205-5p restricted oxidative stress and inflammation in H/R rat hippocampal neurons cells. The inhibition of miR-205-5p reversed the effects of DEX, while the overexpression of HMGB1 reversed the effects of miR-205-5p overexpression in H/R rat hippocampal neurons cells. Dual luciferase reporter assay showed miR-205-5p directly targeted HMGB1.
DEX improved I/R injury by suppressing brain oxidative stress and inflammation DEX improved I/R injury by suppressing brain oxidative stress and inflammation through activating miR-205-5p/HMGB1 axis through activating miR-205-5p/HMGB1 axis.
探讨右美托咪定（DEX）对脑缺血再灌注（I/R）损伤中 miR-205-5p/HMGB1 轴的影响。
建立 I/R 大鼠模型和大鼠海马神经元细胞缺氧/复氧（H/R）细胞模型。通过转染 miR-205-5p 模拟物或抑制剂过表达或抑制 miR-205-5p。通过转染过表达质粒（OE-HMGB1）过表达 HMGB1。TTC 染色法测定梗死体积。通过测定活性氧（ROS）、丙二醛（MDA）和超氧化物歧化酶（SOD）评估氧化应激，通过测定白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）评估炎症。通过双荧光素酶报告实验证实 miR-205-5p 与 HMGB1 之间的结合。采用 RT-qPCR 法检测 miR-205-5p 和 HMGB1 的表达水平。采用 Western blot 法检测 HMGB1、核因子红细胞 2 相关因子 2（Nrf2）、谷胱甘肽过氧化物酶（GPx）、谷胱甘肽还原酶（GR）、血红素加氧酶 1（HO-1）和过氧化氢酶（CAT）的蛋白表达水平。
DEX 治疗可显著降低 I/R 大鼠脑梗死体积，降低 Longa 神经功能评分，并抑制 I/R 大鼠脑组织氧化应激和炎症，这些作用均可被 miR-205-5p 抑制所逆转。DEX 治疗或过表达 miR-205-5p 均可抑制 H/R 大鼠海马神经元细胞氧化应激和炎症。抑制 miR-205-5p 可逆转 DEX 的作用，而过表达 HMGB1 可逆转 H/R 大鼠海马神经元细胞中 miR-205-5p 过表达的作用。双荧光素酶报告实验显示 miR-205-5p 可直接靶向 HMGB1。
DEX 通过激活 miR-205-5p/HMGB1 轴抑制脑氧化应激和炎症，从而改善 I/R 损伤。
