Downregulation of miR-1184 serves as a diagnostic biomarker in neonatal sepsis and regulates LPS-induced inflammatory response by inhibiting IL-16 in monocytes

Neonatal sepsis (NS) remains a global problem. In the present study, abnormal expression of microRNA-1184 (miR-1184) was detected in neonates with NS and it was endeavored to investigate the diagnostic value of miR-1184, as well as its regulatory role in lipopolysaccharide (LPS)-induced inflammatory response in vitro. Furthermore, the correlation between interleukin-16 (IL-16) and miR-1184 was investigated to elucidate the pathological mechanisms of NS development. Reverse transcription-quantitative PCR was used to detect the expression of miR-1184. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic value of miR-1184 in NS. Furthermore, a sepsis cell model was established by using LPS-induced monocytes to explore the effect of miR-1184 on the inflammatory response. The levels of inflammatory cytokines were determined by ELISA. A luciferase reporter assay was used to investigate the direct targeting interaction between miR-1184 and IL-16. The results indicated that the serum levels of miR-1184 in neonates with sepsis were decreased and miR-1184 had a high diagnostic value when differentiating NS from respiratory conditions in neonates. In vitro, the expression of miR-1184 in monocytes was inhibited by LPS and overexpression of miR-1184 reversed the effect of LPS to stimulate the inflammatory response. IL-16 was demonstrated to be a target of miR-1184 and a negative correlation between them was identified in patients with NS. The inflammatory response inhibited by miR-1184 mimics was enhanced by overexpression of IL-16 in LPS-induced monocytes. In conclusion, decreased levels of serum miR-1184 may be a potential diagnostic biomarker for NS. In addition, miR-1184 inhibited the LPS-induced inflammatory response by targeting IL-16 in monocytes, suggesting that the miR-1184/IL-16 axis may be a potential therapeutic target for NS.