IADR Abstract Archives
Influence of Polarized Macrophages on Cell Cementoblastic Differentiation
Objectives: Although macrophage (Mφ) polarization has demonstrated to play crucial roles in cell osteogenesis across the cascade of periodontal regeneration, how the polarized Mφ phenotypes influence the cementoblastic differentiation of periodontal ligament stem cells (PDLSCs) remains unknown.
Methods: In the present study, THP-1 monocytes were induced to polarize into M0, M1 and M2 subsets and those polarized Mφs were used to assess their influences on PDLSC cementogenesis in both conditioned medium-based and transwell-based coculture systems. Furthermore, the potential pathways, cyto/chemokines and molecules involved in Mφ-mediated cementoblastic differentiation of PDLSCs were screened and identified in terms of Luminex liquid chip, LncRNA array, ChIRP-MS, PRM and RIP assays. Finally, the treated cell sheets combined with treated dentin matrix were subcutaneously transplanted into nude mice to verify the in vitro outcomes.
Results: In both systems, M2 subsets increased cementoblastic differentiation-related gene/protein expression levels and ALP activity in cocultured PDLSCs, IL-10 and VEGF secreted by M2 macrophage can activate the AKT pathway, and therefore regulate the cell cementoblastic differentiation. However, TNF-α and IL-1β secreted by M1 macrophage decreased cementoblastic differentiation-related gene/protein expression levels and ALP activity, and the inflammation-damaged cementoblastic differentiation of PDLSCs might be due to their negative effects on mitochondrial functions of stem cells in vitro and in vivo. Further, we found that lncRNA GACAT2-binding PKM1/2 regulates cell mitochondrial function and cementoblastic differentiation in an inflammatory environment.
Conclusions: Our data for the first time suggest that the Mφs and their secreted cytokines are key modulators during cell cementoblastic differentiation and periodontal regeneration. Although the mechanisms involved in inflammation-mediated PDLSC cementoblastic differentiation remain unclear, modulating macrophage polarization and mitochondrial function of PDLSCs can be considered as a key therapeutic target for true periodontal regeneration.
Methods: In the present study, THP-1 monocytes were induced to polarize into M0, M1 and M2 subsets and those polarized Mφs were used to assess their influences on PDLSC cementogenesis in both conditioned medium-based and transwell-based coculture systems. Furthermore, the potential pathways, cyto/chemokines and molecules involved in Mφ-mediated cementoblastic differentiation of PDLSCs were screened and identified in terms of Luminex liquid chip, LncRNA array, ChIRP-MS, PRM and RIP assays. Finally, the treated cell sheets combined with treated dentin matrix were subcutaneously transplanted into nude mice to verify the in vitro outcomes.
Results: In both systems, M2 subsets increased cementoblastic differentiation-related gene/protein expression levels and ALP activity in cocultured PDLSCs, IL-10 and VEGF secreted by M2 macrophage can activate the AKT pathway, and therefore regulate the cell cementoblastic differentiation. However, TNF-α and IL-1β secreted by M1 macrophage decreased cementoblastic differentiation-related gene/protein expression levels and ALP activity, and the inflammation-damaged cementoblastic differentiation of PDLSCs might be due to their negative effects on mitochondrial functions of stem cells in vitro and in vivo. Further, we found that lncRNA GACAT2-binding PKM1/2 regulates cell mitochondrial function and cementoblastic differentiation in an inflammatory environment.
Conclusions: Our data for the first time suggest that the Mφs and their secreted cytokines are key modulators during cell cementoblastic differentiation and periodontal regeneration. Although the mechanisms involved in inflammation-mediated PDLSC cementoblastic differentiation remain unclear, modulating macrophage polarization and mitochondrial function of PDLSCs can be considered as a key therapeutic target for true periodontal regeneration.