Yang Guang, Zhao Yuan
Department of Pediatrics, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China.
Department of Neonatal Internal Medicine, Shanxi Children's Hospital, Taiyuan, Shanxi 030013, P.R. China.
Exp Ther Med. 2021 Feb;21(2):152. doi: 10.3892/etm.2020.9584. Epub 2020 Dec 17.
Acute lung injury (ALI) is a main reason for neonatal death. Studying the molecular mechanism behind neonatal ALI is critical for the development of therapeutic strategies. The present study explored microRNA (miR)-490-3p-mediated regulatory effects on lipopolysaccharide (LPS)-induced neonatal ALI. Initially, LPS (10 mg/kg body weight) was injected to 3-8 day old neonatal SD rats to induce ALI, and LPS (100 ng/ml) was used to treat lung epithelial cells to construct an ALI model . Next, miR-490-3p, pro-inflammatory factors (that included IL-1β, IL-6 and TNFα), interleukin 1 receptor associated kinase 1 (IRAK1) and TNF receptor associated factor 6 (TRAF6) mRNA expression levels in lung tissues and epithelial cells were assessed via reverse transcription-quantitative PCR. In addition, miR-490-3p mimics were adopted to construct its overexpressed cell model, and Cell Counting Kit-8 and BrdU assays were conducted to assess cell viability. Furthermore, the miR-490-3p target, IRAK was predicted by bioinformatics analysis and verified via Dual-luciferase reporter gene assay. The results revealed that miR-490-3p was markedly downregulated in an LPS-induced rat ALI model, while IL-1β, IL-6, TNFα, IRAK1 and TRAF6 were all upregulated and negatively correlated with miR-490-3p expression. Moreover, overexpressed miR-490-3p significantly inhibited LPS-induced lung epithelial cell injury and inflammatory response. Mechanistically, miR-490-3p targeted and attenuated IRAK1 expression, which thus inactivated the LPS-mediated TRAF6/NF-κB pathway. Overall, the present study indicated that miR-490-3p overexpression significantly inhibited LPS-induced ALI and inflammatory responses by restricting the IRAK1/TRAF6 pathway.
急性肺损伤（ALI）是新生儿死亡的主要原因。研究新生儿ALI背后的分子机制对于治疗策略的开发至关重要。本研究探讨了微小RNA（miR）-490-3p对脂多糖（LPS）诱导的新生儿ALI的调控作用。首先，将LPS（10 mg/kg体重）注射到3-8日龄的新生SD大鼠中以诱导ALI，并使用LPS（100 ng/ml）处理肺上皮细胞以构建ALI模型。接下来，通过逆转录-定量PCR评估肺组织和上皮细胞中miR-490-3p、促炎因子（包括IL-1β、IL-6和TNFα）、白细胞介素1受体相关激酶1（IRAK1）和肿瘤坏死因子受体相关因子6（TRAF6）的mRNA表达水平。此外，采用miR-490-3p模拟物构建其过表达细胞模型，并进行细胞计数试剂盒-8和BrdU测定以评估细胞活力。此外，通过生物信息学分析预测miR-490-3p的靶标IRAK，并通过双荧光素酶报告基因测定进行验证。结果显示，在LPS诱导的大鼠ALI模型中，miR-490-3p明显下调，而IL-1β、IL-6、TNFα、IRAK1和TRAF6均上调，且与miR-490-3p表达呈负相关。此外，过表达miR-490-3p可显著抑制LPS诱导的肺上皮细胞损伤和炎症反应。机制上，miR-490-3p靶向并减弱IRAK1表达，从而使LPS介导的TRAF6/NF-κB通路失活。总体而言，本研究表明，miR-490-3p过表达通过限制IRAK1/TRAF6通路显著抑制LPS诱导的ALI和炎症反应。
