miRNA-489-3p Improves Sepsis-Induced Lung Injury by Regulating Toll-Like Receptor 4 (TLR4) Signaling Pathway

Aim: To discuss miRNA-489-3p in sepsis-induced lung injury. Materials and methods: Using NR-8383 as research cell in our study, and using LPS stimulation to sepsis induced lung injury vitro model. Measuring cell proliferation by MTS assay; using Elisa assay to measure IL-1 beta, IL-6 and TNF-alpha concentration; apoptosis cell number and apoptosis rate were evaluated using TUNEL and flow cytometry; gene and protein were measured by RT-PCR and WB assay; measuring p-NF-kappa B(p65) nuclear volume by Immunofluorescence (IF); using Luciferase reporter assay to analysis miRNA-489-3p and TLR4 correlation. Results: Cell proliferation rate significantly down-regulated (P<0.001), apoptosis cell number and apoptosis rate significantly increased (P < 0.001); IL-1 beta, IL-6 and TNF-alpha concentrations significantly up-regulated (P < 0.001); TLR4 and MyD88 gene and protein significantly increased (P < 0.001), NF-kappa B(p65) mRNA and p-NF-kappa B(p65) protein and nuclear volume significantly increased (P < 0.001). However, with miRNA-489-3p supplement, the cell proliferation rate, apoptosis cell number and apoptosis rate were significantly improved (P < 0.001, respectively) via TLR4, MyD88 and NF-kappa B(p65) mRNA and protein significantly depressing (P < 0.001, respectively). By LUC assay, miRNA-489-3p could target to TLR4 in NR-8383 cell. Conclusion: miRNA-489-3p overexpression had effect to improve sepsis induced lung injury via regulation TLR4/MyD88/NF-kappa B(p65).