Ningxia Medical University, Yinchuan, China; Department of Critical Care Medicine, Harrison International Peace Hospital, Hengshui, China.
Key Laboratory of Ningxia Stem Cell and Regenerative Medicine, Institute of Medical Sciences, General Hospital of Ningxia Medical University, Yinchuan, China.
Int Immunopharmacol. 2024 Apr 20;131:111864. doi: 10.1016/j.intimp.2024.111864. Epub 2024 Mar 13.
Alveolar epithelial barrier dysfunction is one of the pathological features of sepsis-acute lung injury(ALI). However, the molecular mechanisms that regulate the function of alveolar epithelial barrier remain unclear. This study aimed to determine the regulatory role of miR-186-5p in alveolar epithelial barrier function in sepsis-ALI and its underlying molecular mechanism.
We established sepsis-ALI models in vivo and in vitro, detected the miR-186-5p and wnt5a/β-catenin expressions, and observed the functional changes of the alveolar epithelial barrier by miR-186-5p overexpression. We used rescue experiments to clarify whether miR-186-5p works through wnt5a/β-catenin.
miR-186-5p expression was decreased, wnt5a expression was increased, and the wnt5a/β-catenin signaling pathway was activated in mouse lung tissues and A549 cells after inflammatory stimulation. miR-186-5p overexpression resulted in wnt5a/β-catenin signaling pathway inhibition, decreased apoptosis in A549 cells, improved alveolar epithelial barrier function, reduced lung tissue injury in ALI mice, decreased IL-6 and TNF-α levels, and increased claudin4 and ZO-1 expression. Using miRNA-related database prediction and dual-luciferase reporter gene analysis, the targeting relationship between miR-186-5p and wnt5a was determined. The protective effect produced by miR-186-5p overexpression on the alveolar barrier was reversed after the application of the wnt5a/β-catenin activator Licl.
Our experimental data suggest miR-186-5p targets the wnt5a/β-catenin pathway, thereby regulating alveolar epithelial barrier function. Furthermore, both miR-186-5p and wnt5a/β-catenin are potential therapeutic targets that could impact sepsis-ALI.
肺泡上皮屏障功能障碍是脓毒症-急性肺损伤（ALI）的病理特征之一。然而，调节肺泡上皮屏障功能的分子机制尚不清楚。本研究旨在确定 miR-186-5p 在脓毒症-ALI 中对肺泡上皮屏障功能的调节作用及其潜在的分子机制。
我们在体内和体外建立了脓毒症-ALI 模型，检测了 miR-186-5p 和 wnt5a/β-catenin 的表达，并通过 miR-186-5p 的过表达观察了肺泡上皮屏障的功能变化。我们使用挽救实验来阐明 miR-186-5p 是否通过 wnt5a/β-catenin 发挥作用。
在炎症刺激后，小鼠肺组织和 A549 细胞中 miR-186-5p 表达降低，wnt5a 表达增加，wnt5a/β-catenin 信号通路被激活。miR-186-5p 的过表达导致 wnt5a/β-catenin 信号通路的抑制，减少 A549 细胞的凋亡，改善肺泡上皮屏障功能，减轻 ALI 小鼠的肺组织损伤，降低 IL-6 和 TNF-α 的水平，并增加 Claudin4 和 ZO-1 的表达。通过 miRNA 相关数据库预测和双荧光素酶报告基因分析，确定了 miR-186-5p 与 wnt5a 之间的靶向关系。应用 wnt5a/β-catenin 激活剂 Licl 后，miR-186-5p 过表达产生的对肺泡屏障的保护作用被逆转。
我们的实验数据表明，miR-186-5p 靶向 wnt5a/β-catenin 通路，从而调节肺泡上皮屏障功能。此外，miR-186-5p 和 wnt5a/β-catenin 均可能成为影响脓毒症-ALI 的潜在治疗靶点。
