MiR-216a-5p alleviates LPS-induced inflammation in the human bronchial epithelial cell by inhibition of TGF-β1 signaling via down-regulating TGFBR2

Abstract

Objective: Bronchopneumonia is a common respiratory infection disease and is the leading cause of hospitalization in children under 5 years of age. Inflammation is the primary response caused by bronchopneumonia. But the detailed underlying mechanism of inflammation in bronchopneumonia remains unclear. Therefore, this study focused on studying the effect of miR-216a-5p on inflammation induced by bronchopneumonia and investigate the potential mechanism underlying it.Methods: Human bronchial epithelial cells (BEAS-2B) were stimulated using lipopolysaccha-rides (LPS) to trigger bronchopneumonia in vitro. The production of interleukin (IL)-1β, IL-6, and Tumor necrosis factor (TNF)-α was measured using the enzyme-linked immunosorbent assay. The luciferase assay was conducted to explore the relationship between miR-216a-5p and TGFBR2. Quantitative real-time polymerase chain reaction and western blot were used to detect the gene expression.Results: miR-216a-5p gene expression decreased in BEAS-2B cells stimulated by LPS. Overexpression of miR-216a-5p suppressed the elevated levels of IL-1β, IL-6, and TNF-α induced by LPS. Transforming growth factor-beta receptor 2 (TGFBR2) proved to be a direct target of miR-216a-5p, and they negatively modulated TGFBR2 expression. In addition, overexpression of miR-216a-5p inhibited LPS-induced protein levels of TGFBR2,transforming growth factor (TGF)-β1, and phosphorylation of SMAD family member 2 (smad2),. This ectopic expression of miR-216a-5p was restored by overexpressed TGFBR2.Conclusion: miR-216a-5p was decreased in LPS-stimulated BEAS-2B cells. Overexpressed miR-216a-5p suppressed LPS-induced inflammation in BEAS-2B cells by inhibition of TGF-β1 signal-ing via down-regulating TGFBR2. miR-216a-5p may be a valuable target for anti-inflammation treatment in bronchopneumonia.