LAUSR

BACKGROUND Cementum regeneration was regarded as the critical goal for periodontal regeneration. M2 macrophage-based therapy was expected to be a promising strategy for it. However, little is known about the effects of M2 macrophages on cementoblast mineralization and tropism, especially under inflammation. Here we first investigated the crosstalk between M2 macrophages and porphyromonas gingivalis (P. gingivalis)-stimulated cementoblasts. MATERIALS AND METHODS M2 macrophages were induced with interleukin (IL)-4, and identified. CC-chemokine ligand 2 (CCL2) expression and secretion of inflammatory cementoblasts was detected by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), western blotting (WB), immunohistochemistry for the apical periodontitis (AP) mice, and enzyme-linked immunosorbent assay. Crystal violet staining was used to observe macrophage migration. Conditional medium (CM) and transwell coculture methods were applied to evaluate the effects of M2 macrophages on cementum mineralization with or without P. gingivalis, and to explore the mechanism. Mineralization-related markers and pathway-related proteins were measured by RT-qPCR and WB. RESULTS M2 macrophages were identified successfully. We found an increase of CCL2 in cementoblasts and their supernatant. Also, higher CCL2 in cementoblasts was observed in AP model. Superior recruitment of M2 macrophages to supernatant from P. gingivalis-stimulated cementoblasts or CCL2-containing medium was verified. Moreover, CM2 and Trans-M2 showed better mineralization-accelerating and -rescuing effects when compared to their controls, and application of p38 inhibitor partially blocked the promotion. CONCLUSIONS Our study demonstrated the inflammation-targeting and mineralization-promoting effects of M2 macrophages on cementoblasts, which may provide evidences for M2 macrophage-based cementum regeneration. This article is protected by copyright. All rights reserved.