[MiR-142-3p inhibits lipopolysaccharide-induced inflammatory response in human periodontal ligament cells through targeting IRAK1].

To investigate the effects of miR-142-3p overexpression on secretion of inflammatory factors in human periodontal ligament cells (hPDLCs) induced by lipopolysaccharide (LPS) and its underlying mechanism.hPDLCs were cultured by tissue cultivation in vitro and treated with various concentrations of LPS for 6, 12, 24 and 48 h. hPDLCs were treated with miR-142-3p mimics for 24 h in the presence of 2.0 μg/mL LPS and the expression levels of inflammatory factors (TNF-α, IL-6 and IL-1β) were detected by ELISA assay. The target relationship between miR-142-3p and interleukin-1 receptor- associated kinase 1 (IRAK1) was detected by dual-luciferase reporter assay. The miR-142-3p and IRAK1 mRNA expression was measured by qRT-PCR. The protein expression levels of IRAK1, TLR4 and NF-κB were detected by Western blotting. Statistical analysis was performed using SPSS 16.0 software package.The miR-142-3p expression level was decreased significantly at 24 h in 2.0 μg/mL LPS-treated hPDLCs (P 0.05). Moreover, miR-142-3p overexpression markedly diminished the protein expression of TLR4 and phosphorylated NF-κB in LPS-treated hPDLCs (P<0.05).Overexpression of miR-142-3p can alleviate the inflammatory response induced by LPS in hPDLCs and the underlying mechanism may be associated with targeting and inhibiting IRAK1 expression leading to suppression of TLR4/NF-κB inflammatory signaling pathway through which miR-142-3p overexpression protects peridentium against inflammation.