Ye Lingling, Cheng Xiaoe, Shi Yinqi, Liu Ziye, Xiong Yingfen, Huang Yuanlu
Department of Anesthesiology, Medical Center of Anesthesiology and Pain, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China.
Department of Anesthesia Operation, Medical Center of Anesthesiology and Pain, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China.
Neuroreport. 2023 Apr 5;34(6):357-367. doi: 10.1097/WNR.0000000000001901. Epub 2023 Mar 20.
Postoperative cognitive dysfunction (POCD), a neurological complication after surgery, is common among the elderly in particular. Maternal expression gene 3 (MEG3) is a novel long non-coding RNA (lncRNA) that contributes to glial cell activation and inflammation. We aim to further explore its role in POCD. Mice were induced with sevoflurane anesthesia and underwent orthopedic surgery to establish a POCD model. BV-2 microglia activation was induced by lipopolysaccharide. The overexpressed lentiviral plasmid lv-MEG3 and its control were injected into mice. pcDNA3.1-MEG3, has-miR-106a-5p mimic, and its negative control were transfected into BV-2 cells. The expressions of has-miR-106a-5p MEG3 and Sirtuin 3 (SIRT3) in rat hippocampus and BV-2 cells were quantitatively detected. Levels of SIRT3, TNF-α, and IL-1β were detected by western blot, levels of TNF-α and IL-1β by ELISA, and expression of GSH-Px, SOD, and MDA by kits. The targeting relationship between MEG3 and has-miR-106a-5p was confirmed using bioinformatics and dual-luciferase reporter assay. LncRNA MEG3 was down-regulated in POCD mice, whereas has-miR-106a-5 levels were up-regulated. Overexpression of MEG3 could attenuate cognitive dysfunction and inflammatory response in POCD mice, inhibit lipopolysaccharide-induced inflammatory response and oxidative stress in BV-2 cells, and promote has-miR-106a through competitive binding with has-miR-106a-5-5 expression of target gene SIRT3. Overexpression of has-miR-106a-5p had a reverse effect on overexpression of MEG3 functioning on lipopolysaccharide-induced BV-2 cells. LncRNA MEG3 could inhibit the inflammatory response and oxidative stress via has-miR-106a-5p/SIRT3, thereby reducing POCD, which might be a potential biological target for the diagnosis and treatment of clinical POCD.
术后认知功能障碍（POCD）是手术后的一种神经并发症，在老年人中尤为常见。母系表达基因3（MEG3）是一种新型的长链非编码RNA（lncRNA），它参与神经胶质细胞的激活和炎症反应。我们旨在进一步探讨其在POCD中的作用。采用七氟醚麻醉诱导小鼠并进行骨科手术以建立POCD模型。用脂多糖诱导BV-2小胶质细胞活化。将过表达的慢病毒质粒lv-MEG3及其对照注射到小鼠体内。将pcDNA3.1-MEG3、has-miR-106a-5p模拟物及其阴性对照转染到BV-2细胞中。定量检测大鼠海马和BV-2细胞中has-miR-106a-5p、MEG3和沉默调节蛋白3（SIRT3）的表达。通过蛋白质免疫印迹法检测SIRT3、肿瘤坏死因子-α（TNF-α）和白细胞介素-1β（IL-1β）的水平，通过酶联免疫吸附测定法检测TNF-α和IL-1β的水平，并用试剂盒检测谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）和丙二醛（MDA）的表达。使用生物信息学和双荧光素酶报告基因检测法证实MEG3与has-miR-106a-5p之间的靶向关系。lncRNA MEG3在POCD小鼠中表达下调，而has-miR-106a-5的水平上调。MEG3的过表达可减轻POCD小鼠的认知功能障碍和炎症反应，抑制脂多糖诱导的BV-2细胞炎症反应和氧化应激，并通过与靶基因SIRT3的has-miR-106a-5-5表达竞争性结合来促进has-miR-106a的表达。has-miR-106a-5p的过表达对脂多糖诱导的BV-2细胞中MEG3过表达的作用具有相反的影响。lncRNA MEG3可通过has-miR-106a-5p/SIRT3抑制炎症反应和氧化应激，从而减轻POCD，这可能是临床POCD诊断和治疗的潜在生物学靶点。
