Combined Effects of Growth Hormone and Mineral Trioxide Aggregate on Growth, Differentiation, and Angiogenesis in Human Dental Pulp Cells

Introduction The aim of this study was to evaluate the effects of growth hormone (GH) on mineral trioxide aggregate (MTA) with regard to cell adhesion, growth, odontoblastic differentiation, and angiogenesis in human dental pulp cells and the underlying signal pathway mechanisms. Methods Cell adhesion and proliferation were assessed by adhesion analysis and cell counting. Differentiation was examined by alkaline phosphatase activity, alizarin red staining, and reverse transcriptase polymerase chain reaction for marker genes. Angiogenesis was evaluated by human umbilical vein endothelial cell migration and capillary tube formation assays. Signaling pathways were analyzed by Western blotting and confocal microscopy. Results Combined treatment with GH and MTA enhanced cell adhesion, growth, alkaline phosphatase activity, calcified nodules, expression of marker mRNAs, migration, and capillary tube formation, compared with treatment with MTA or GH alone. In addition, GH plus MTA increased expression of bone morphogenetic protein-2 mRNA, phosphorylation of Smad 1/5/8, extracellular signal-regulated kinase, JNK, and p38 MAPK, and increased the levels of the transcription factors Runx2 and Osterix, compared with MTA alone. Conclusions Collectively, our results demonstrate that a combination of MTA and GH promotes cell adhesion, growth, differentiation, and angiogenesis of MTA in human dental pulp cells via the activation of bone morphogenetic protein and MAPK pathway.