Department of Emergency, The Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
Mol Med Rep. 2020 Dec;22(6):5095-5104. doi: 10.3892/mmr.2020.11601. Epub 2020 Oct 14.
Sepsis is a serious clinical condition characterized by systemic inflammation. The long noncoding RNA (lncRNA) highly upregulated in liver cancer (HULC) was validated to partake in the development of sepsis. The present study aimed to investigate the potential mechanism of HULC in lipopolysaccharide (LPS)‑induced sepsis. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis was employed to examine the expression of HULC, microRNA (miR)‑128‑3p, Rac family small GTPase 1 (RAC1) and pro‑inflammatory factors [IL‑6, TNF‑α, intercellular adhesion molecule (ICAM1) and vascular cell adhesion molecule (VCAM1)] in the serum of patients with sepsis or LPS‑induced human dermal microvascular endothelial cells (HMEC‑1). Flow cytometry and western blot assays were performed to detect cell apoptosis. The targeted relationship among HULC, miR‑128‑3p and RAC1 was confirmed by a dual‑luciferase reporter assay, RNA binding protein immunoprecipitation (RIP) assay and RNA pull‑down assay. HULC and RAC1 were found to be upregulated, and miR‑128‑3p was downregulated in the serum of patients with sepsis and LPS‑stimulated HMEC‑1 cells. LPS promoted apoptosis and inflammation, which were decreased by silencing of HULC. HULC targeted miR‑128‑3p and negatively regulated its expression. HULC knockdown protected HMEC‑1 cells from LPS‑induced injury by upregulating miR‑128‑3p. RAC1 was a target of miR‑128‑3p, and gain of RAC1 also relieved the silencing of HULC‑mediated suppressive effects on apoptosis and inflammation in LPS‑stimulated HMEC‑1 cells. In conclusion, HULC knockdown partially reversed LPS‑induced sepsis via the regulation of miR‑128‑3p/RAC1 axis.
脓毒症是一种以全身炎症为特征的严重临床病症。长链非编码 RNA（lncRNA）在肝癌中高表达（HULC）已被证实参与了脓毒症的发生发展。本研究旨在探讨 HULC 在脂多糖（LPS）诱导的脓毒症中的潜在作用机制。采用逆转录定量聚合酶链反应（RT-qPCR）和 Western blot 分析检测脓毒症患者或 LPS 诱导的人真皮微血管内皮细胞（HMEC-1）血清中 HULC、微小 RNA（miR）-128-3p、Rac 家族小 GTP 酶 1（RAC1）和促炎因子[白细胞介素（IL）-6、肿瘤坏死因子（TNF）-α、细胞间黏附分子（ICAM1）和血管细胞黏附分子（VCAM1）]的表达。采用流式细胞术和 Western blot 检测细胞凋亡。通过双荧光素酶报告基因检测、RNA 结合蛋白免疫沉淀（RIP）检测和 RNA 下拉实验验证 HULC、miR-128-3p 和 RAC1 之间的靶向关系。结果发现，脓毒症患者和 LPS 刺激的 HMEC-1 细胞中 HULC 和 RAC1 上调，miR-128-3p 下调。沉默 HULC 可促进 LPS 诱导的 HMEC-1 细胞凋亡和炎症反应。HULC 靶向 miR-128-3p 并负调控其表达。沉默 HULC 可通过上调 miR-128-3p 减轻 LPS 诱导的 HMEC-1 细胞损伤。RAC1 是 miR-128-3p 的靶基因，过表达 RAC1 也可缓解 LPS 刺激的 HMEC-1 细胞中沉默 HULC 介导的对细胞凋亡和炎症的抑制作用。综上所述，沉默 HULC 通过调节 miR-128-3p/RAC1 轴部分逆转 LPS 诱导的脓毒症。
