miR-146a-5p attenuates IL-1β-induced IL-6 and IL-1β expression in a cementoblast-derived cell line

Oral Dis. 2020 Sep;26(6):1308-1317. doi: 10.1111/odi.13333. Epub 2020 Apr 5.

Abstract

Objective: miR-146a is widely induced during the immune response. However, little is known about the biogenesis, function and mechanism of miR-146a in cementoblasts during the pathogenesis of periodontitis. This study aimed to investigate the effects of miR-146a in murine cementoblast-derived OCCM-30 cells following IL-1β stimulation.

Materials and methods: OCCM-30 cells were cultured and exposed to IL-1β. IL-6, IL-1β and TNF-α, and miR-146a-5p expression was assessed by qRT-PCR. Mimics/inhibitors were transiently transfected into cells to determine the function of miR-146a-5p. Signalling pathways including p38 MAPK, ERK1/2 and NF-κB were studied by using specific inhibitors. The indicated proteins were measured by Western blot analysis and ELISA.

Results: In IL-1β-stimulated OCCM-30 cells, the expression levels of miR-146a-5p along with IL-6 and IL-1β increased in a time-dependent manner. The ERK1/2, p38 MAPK and NF-κB pathway were activated upon IL-1β stimulation. Blocking the NF-κB pathway decreased IL-6, IL-1β and miR-146a-5p expression. The overexpression of miR-146a-5p reduced IL-6 and IL-1β expression, while the inhibition of miR-146a-5p increased IL-6 and IL-1β expression in IL-1β-treated OCCM-30 cells. miR-146a-5p attenuated IL-6 and IL-1β expression via the IRAK1/TRAF6 pathway.

Conclusion: This study suggested that miR-146a-5p attenuates IL-1β-induced inflammatory factors in cementoblast-derived cell line.

Keywords: dental cementum; interleukin-1β; interleukin-6; miR-146a-5p; periodontitis.