Downregulation of lncRNA ANRIL Inhibits Osteogenic Differentiation of Periodontal Ligament Cells via Sponging miR-7 through NF-κB Pathway

Abstract

Background Long non-coding RNAs (lncRNAs) are dysregulation in periodontitis development and involved in osteogenesis. The current study aimed was to investigate the function of lncRNA ANRIL in periodontal ligament cells (PDLCs) and potential molecular mechanisms.Methods Firstly, the level of ANRIL was tested by qPCR. Then PDLCs were treated with a mineralizing solution to induce the osteogenic differentiation. ALP activity was measured and protein levels of BMP2, Osterix, and OCN were measured by western blot. A target of ANRIL was verified using dual-luciferase reporter assay. MiR-7 level was measured by qPCR and the signalings of NF-κB pathway were tested by western blot.Results ANRIL expression was downregulated in PDL tissues. Next, ALP activity and protein levels of BMP2, Osterix, and OCN were reduced to show PDLCs were differentiated. ANRIL level was increased in differential PDLCs, and which knockdown inhibited osteogenic differentiation. Then, miR-7 was found as a target of ANRIL. The miR-7 level was upregulated in PDL tissues and reduced in differential PDLCs. Inhibition of miR-7 suppressed ALP activity and BMP2, Osterix, and OCN expression. Moreover, inhibition of miR-7 reversed the effects on the osteogenic differentiation induced by knockdown of ANRIL. Besides, the levels of p-P65 and p-IκBα were elevated by ANRIL downregulation and were rescued by suppressing miR-7.Conclusions Knockdown of ANRIL inhibited osteogenic differentiation via sponging miR-7 through the NF-κB pathway, suggesting that ANRIL might be a therapeutic target for periodontitis.