Deregulated Expression of miR-483-3p Serves as a Diagnostic Biomarker in Severe Pneumonia Children with Respiratory Failure and Its Predictive Value for the Clinical Outcome of Patients.

Severe pneumonia in children is a group of inflammatory diseases of respiratory tract caused by pathogenic microorganisms. Increasing evidence suggested the crucial effects of microRNA on inflammatory diseases. This study aimed to reveal the expression and role of miR-483-3p in the serum of children with severe pneumonia, and to explore the effect of miR-483-3p on the biological function of lipopolysaccharide (LPS)-induced MRC-5 cells. MRC-5 cells were disposed with LPS to construct an in vitro pneumonia cell model. The relative expression level of miR-483-3p was measured by qRT-PCR. ROC curve was used to evaluate the diagnostic value of miR-483-3p in severe pneumonia. The Kaplan-Meier curve was performed to test the characteristics of survival distribution of different miRNA classifications. Cell viability and apoptosis were performed by CCK-8 assay and flow cytometry. IL-1β, TNF-α, and IL-6 were detected by ELISA. Luciferase reporter gene assay and western blot analysis were performed to detect the interaction between miR-483-3p and IGF-1. The expression of serum miR-483-3p in severe pneumonia patients was higher than in controls. The AUC value of the ROC curve was 0.919, indicating that miR-483-3p had diagnostic value for severe pneumonia. The survival curve showed that patients with high expression of miR-483-3p had higher mortality. Cell viability and apoptosis assay showed that overexpression of miR-483-3p suppressed cell proliferation and promoted apoptosis. And upregulation of miR-483-3p promoted generation of inflammatory cytokines. Luciferase report gene assay and western blot assay both illustrated that IGF-1 might be the target gene of miR-483-3p. Serum miR-483-3p can be used as a biomarker for the diagnosis of severe pneumonia. High expression of miR-483-3p promoted the development of severe pneumonia.