Qian Jin, Liu Ke-Jun, Zhong Chang-Hui, Xian Li-Na, Hu Zhi-Hua
Key Laboratory of Emergency and Trauma of Ministry of Education, Department of Intensive Care Medicine, The First Affiliated Hospital of Hainan Medical University, Haikou, China.
Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Basic Medicine and Life Sciences, Hainan Medical University, Haikou, China.
J Thorac Dis. 2024 Oct 31;16(10):6616-6633. doi: 10.21037/jtd-24-65. Epub 2024 Oct 30.
Acute lung injury (ALI) is one of the most common critical illnesses in clinical practice, with sepsis being the most common cause of ALI. Sivelestat sodium (SV) hydrate is a highly effective inhibitor of neutrophil elastase, specifically targeting ALI related to systemic inflammatory response syndrome. The aim of this study is to examine the mechanisms by which SV can reduce the severity of ALI resulting from sepsis.
Cecum ligation and puncture (CLP) was employed for creating an animal model of ALI caused by sepsis. Primary human pulmonary microvascular endothelial cells (HPMECs) were treated with lipopolysaccharide (LPS) to develop an model of infection-induced ALI. Lung tissue damage was assessed by employing hematoxylin-eosin (H&E) and Masson staining. Lung edema was determined by calculating the lung wet-to-dry weight ratio. Lung tissue and cell samples were analyzed using Enzyme-linked immunosorbent assay (ELISA) to detect levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6. The 5-ethynyl-2'-deoxyuridine (EdU) and wound-healing assay were used to determine the cell proliferation and migration, while flow cytometry was used for detecting cell apoptosis. The association between microRNA (miR)-744 and transforming growth factor (TGF)-β1 was discovered and confirmed through the utilization of bioinformatics analyses and dual-luciferase gene reporter assay. The analysis of TGF-β1, p-Smad3, and Smad3 was carried out through western blotting and immunohistochemistry in both and scenarios.
In both and settings of ALI models of sepsis, there was a significant decrease in the level of miR-744-5p, a significant elevation in the expression of inflammatory factors, and a significant intensification of lung tissue damage. Administration of SV resulted in a significant increase in the level of miR-744-5p, suppressed the inflammatory response, and ultimately improved lung injury. Cell proliferation was significantly enhanced by SV and cell apoptosis was inhibited. The protection of SV was significantly reversed by inhibiting the effect of miR-744-5p. The double-luciferase reporter gene assay revealed substantial interactions occurring between miR-744-5p and TGF-β1. The TGF-β/Smad signaling pathway was significantly inhibited by SV, however, the inhibitory effect can be counteracted by utilizing the miR-744-5p inhibitor.
The upregulation of miR-744-5p by SV inhibits the TGF-β/Smad signaling pathway, thereby reducing sepsis-induced ALI.
急性肺损伤（ALI）是临床实践中最常见的危重症之一，脓毒症是ALI最常见的病因。西维来司他钠水合物是一种高效的中性粒细胞弹性蛋白酶抑制剂，专门针对与全身炎症反应综合征相关的ALI。本研究的目的是探讨西维来司他钠减轻脓毒症所致ALI严重程度的机制。
采用盲肠结扎穿刺术（CLP）建立脓毒症所致ALI动物模型。用脂多糖（LPS）处理原代人肺微血管内皮细胞（HPMECs）以建立感染诱导的ALI模型。采用苏木精-伊红（H&E）染色和Masson染色评估肺组织损伤。通过计算肺湿重与干重之比来测定肺水肿。使用酶联免疫吸附测定（ELISA）分析肺组织和细胞样本，以检测肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-1β和IL-6的水平。采用5-乙炔基-2'-脱氧尿苷（EdU）和伤口愈合试验来测定细胞增殖和迁移，同时使用流式细胞术检测细胞凋亡。通过生物信息学分析和双荧光素酶基因报告试验发现并证实了微小RNA（miR）-744与转化生长因子（TGF）-β1之间的关联。在动物模型和细胞模型中，通过蛋白质印迹法和免疫组织化学法对TGF-β1、磷酸化Smad3和Smad3进行分析。
在脓毒症ALI模型的动物和细胞模型中，miR-744-5p水平显著降低，炎症因子表达显著升高，肺组织损伤显著加重。给予西维来司他钠后，miR-744-5p水平显著升高，炎症反应受到抑制，最终改善了肺损伤。西维来司他钠显著增强细胞增殖并抑制细胞凋亡。抑制miR-744-5p的作用可显著逆转西维来司他钠的保护作用。双荧光素酶报告基因试验显示miR-744-5p与TGF-β1之间存在大量相互作用。西维来司他钠显著抑制TGF-β/Smad信号通路，然而，使用miR-744-5p抑制剂可抵消这种抑制作用。
西维来司他钠上调miR-744-5p抑制TGF-β/Smad信号通路，从而减轻脓毒症诱导的ALI。
