REV-ERBs negatively regulate mineralization of the cementoblasts.

Abstract Objective The role of circadian clock in cementogenesis is unclear. This study examines the role of REV-ERBs, one of circadian clock proteins, in proliferation, migration and mineralization of cementoblasts to fill the gap in knowledge. Methods Expression pattern of REV-ERBα in cementoblasts was investigated in vivo and in vitro. CCK-8 assay, scratch wound healing assay, alkaline phosphatase (ALP) and alizarin red S (ARS) staining were performed to evaluate the effects of REV-ERBs activation by SR9009 on proliferation, migration and mineralization of OCCM-30, an immortalized cementoblast cell line. Furthermore, mineralization related markers including osterix (OSX), ALP, bone sialoprotein (BSP) and osteocalcin (OCN) were evaluated. Results Strong expression of REV-ERBα was found in cellular cementum around tooth apex. Rev-erbα mRNA oscillated periodically in OCCM-30 and declined after mineralization induction. REV-ERBs activation by SR9009 inhibited proliferation but promoted migration of OCCM-30 in vitro. Results of ALP and ARS staining suggested that REV-ERBs activation negatively regulated mineralization of OCCM-30. Mechanically, REV-ERBs activation attenuated the expression of OSX and its downstream targets including ALP, BSP and OCN. Conclusions REV-ERBs are involved in cementogenesis and negatively regulate mineralization of cementoblasts via inhibiting OSX expression. Our study provides a potential target regarding periodontal and cementum regeneration.