Effects of long noncoding RNA H19 on cementoblast differentiation, mineralisation, and proliferation

Cementum which is a layer of thin and bone-like mineralised tissue covering tooth root surface is deposited and mineralised by cementoblasts. Recent studies suggested long noncoding RNA H19 (H19) promotes osteoblast differentiation and matrix mineralisation, however, the effect of H19 on cementoblasts remains unknown. This study aimed to clarify the regulatory effects of H19 on cementoblast differentiation, mineralisation, and proliferation. An immortalised murine cementoblast cell line OCCM-30 was used in this study. H19 expression was examined by real-time quantitative polymerase chain reaction (RT-qPCR) during OCCM-30 cell differentiation. OCCM-30 cells were transfected with lentivirus or siRNA to up-regulate or down-regulate H19, then the levels of runt-related transcription factor 2 (Runx2), osterix (Sp7), alkaline phosphatase (Alpl), bone sialoprotein (Ibsp), osteocalcin (Bglap) were tested by RT-qPCR or western blot. Alizarin red staining, ALP activity assay and MTS assay were performed to determine the mineralisation and proliferation ability of OCCM-30 cells. H19 was dramatically increased during OCCM-30 cell differentiation. Overexpression of H19 increased the levels of Runx2, Sp7, Alpl, Ibsp, and Bglap and enhanced ALP activity and the formation of mineral nodules. While down-regulation of H19 suppressed the above cementoblast differentiation genes and inhibited ALP activity and mineral nodule formation. However, the proliferation of OCCM-30 cells was not affected. H19 promotes the differentiation and mineralisation of cementoblasts without affecting cell proliferation.