1. The long non-coding RNA mir155hg promotes NLRP3-inflammasome activation and oxidative stress response in acute lung injury by targeting miR-450b-5p to regulate HIF-1α.
- Author
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Wang, Gui Na, Yang, Miao, Wu, Bo, Huo, Yan, and Xu, Wei
- Abstract
Acute lung injury (ALI) can cause multiple organ dysfunction and a high mortality rate. Inflammatory responses, oxidative stress, and immune damage contribute to their pathogenic mechanisms. We studied the role of the newly discovered lncRNA, Lncmir155hg, in ALI. The levels of Lncmir155hg and miR-450b-5p from mice with ALI were detected via polymerase chain reaction analysis (qRT-PCR) and Fluorescence in situ hybridization (FISH). Pathological changes of lung were detected by HE (hematoxylin and eosin) staining, and HIF-1α, NOD-like receptor 3 (NLRP3) and caspase-1 protein changes were detected by immunohistochemistry. MLE-12 cells proliferation was detected by Cell-Counting Kit 8 analysis, and reactive oxygen species (ROS) was detected via flow cytometry. NLRP3, apoptosis-associated speck-like protein (ASC), and caspase-1 were measured via western blotting, and enzyme-linked immunosorbent assays detected the expression of Inflammatory factors. Lncmir155hg, miR-450b-5p, miR-450b-5p, and HIF-1α targets were predicted using LncTar and miRWalk and confirmed in dual-luciferase reporter assays. In mice with ALI and MLE-12 cells induced by lipopolysaccharide (LPS), Lncmir155hg was high-expressed and miR-450b-5p was low-expressed. sh-Lncmir155hg reduced the damage of lung tissue, the production of inflammatory cytokines and oxidative stress reaction induced by LPS,miR-450b-5p reverses the effect of Lncmir155hg in mice. sh-Lncmir155hg decreased the protein levels of HIF-1α, NLRP3 and caspase-1 in LPS-induced lung tissues. sh-Lncmir155hg + miR-450b-5p inhibitor transfection reversed the effect of sh-Lncmir155hg on the expression of HIF-1α, NLRP3 and caspase-1. Lncmir155hg knockdown induced proliferation and inhibited NLRP3-inflammasome activation and oxidative stress in MLE-12 cells of ALI. miR-450b-5p was identified to have binding with Lncmir155hg, and inhibition of miR-450b-5p eliminated the effect of si-Lncmir155hg in MLE-12 cells of ALI. More importantly, miR-450b-5p was directly combined with HIF-1α, miR-450b-5p mimic promoted proliferation and inhibited activation of inflammasome associated proteins and reaction of oxidative stress, and HIF-1α overexpression abolished these effects. Lncmir155hg aggravated ALI via the miR-450b-5p/HIF-1α axis. In this study, ALI mouse model was prepared by intratracheal injection of LPS. Whole transcriptome sequencing was performed on normal and ALI mice. Through bioinformatics analysis, we found that Lncmir155hg was upregulated in the lung tissue of ALI mice. The upregulation of Lncmir155hg suppressed miR-450b-5p, which further enhanced the expression of HIF-1α, regulating the proliferation of alveolar epithelial cells and regulating NLRP3 inflammasome and oxidative-stress responses of alveolar epithelium and lung tissue, ultimately leading to ALI. [Display omitted] • lncmir155hg promotes NLRP3-inflammasome activation and oxidative stress response in ALI. • lncmir155hg promotes ALI progression by sponging miR-450b-5p. • miR-450b-5p targeted HIF-1α to inhibit lncmir155hg-mediated ALI progression. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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