Li Yexuzi, Ke Junzhong, Peng Chen, Wu Fugen, Song Yukang
Department of Medical Intensive Care Unit, The First People's Hospital of Wenling, Wenling 317500, Zhejiang Province, China.
Department of Neonatal Intensive Care Unit, The First People's Hospital of Wenling, Wenling 317500, Zhejiang Province, China.
Biomed Pharmacother. 2018 Dec;108:271-279. doi: 10.1016/j.biopha.2018.08.064. Epub 2018 Sep 14.
Rapid and accurate diagnosis of neonatal sepsis (NS) is highly warranted because of high associated morbidity and mortality. The study aims to evaluate the effects of miR-300 on inflammatory responses in a septic neonate mouse model.
A septic mouse model was established by intraperitoneal (i.p.) cecal slurry (CS) injection in order to validate the effect of miR-300 on the inflammatory response in endothelial cells. Bioinformatics tools and luciferase activity were employed to detect the target of miR-300. Serum inflammatory factors were determined by ELISA assay. RT-qPCR and western blot analysis were used to determine the gene expressions. Flow cytometry was employed to evaluate cell apoptosis.
Gain- and loss-of-function studies revealed that miR-300 overexpression augmented autophagy, inhibited cell apoptosis, enhanced cell cycle entry in endothelial cells, and decreased inflammatory response through the regulation of pro- and anti-apoptotic factors in endothelial cells. The effect of miR-300on endothelial cells was upregulated after nicotinamide phosphoribosyltransferase (NAMPT) silencing and AMPK/mTOR signaling pathway activation, indicating that miR-300 influences sepsis via suppressing NAMPT and triggering the AMPK/mTOR signaling pathway.
Our study provides evidence indicating that overexpressedmiR-300 enhances autophagy by targeting NAMPT through activation of the AMPK/mTOR signaling pathway in septic mouse models, indicating it may serve as a potential therapeutic target for sepsis.
由于新生儿败血症（NS）相关的高发病率和死亡率，快速准确的诊断非常必要。本研究旨在评估miR-300对败血症新生小鼠模型炎症反应的影响。
通过腹腔注射盲肠匀浆（CS）建立败血症小鼠模型，以验证miR-300对内皮细胞炎症反应的影响。利用生物信息学工具和荧光素酶活性检测miR-300的靶标。通过ELISA测定血清炎症因子。采用RT-qPCR和蛋白质免疫印迹分析来确定基因表达。运用流式细胞术评估细胞凋亡。
功能获得和功能缺失研究表明，miR-300过表达增强自噬、抑制细胞凋亡、促进内皮细胞进入细胞周期，并通过调节内皮细胞中的促凋亡和抗凋亡因子来降低炎症反应。在烟酰胺磷酸核糖转移酶（NAMPT）沉默和AMPK/mTOR信号通路激活后，miR-300对内皮细胞的作用上调，表明miR-300通过抑制NAMPT和触发AMPK/mTOR信号通路影响败血症。
我们的研究提供了证据，表明在败血症小鼠模型中，过表达的miR-300通过激活AMPK/mTOR信号通路靶向NAMPT来增强自噬，这表明它可能作为败血症的潜在治疗靶点。
