Extracellular calcium promotes bone formation from bone marrow mesenchymal stem cells by amplifying the effects of BMP-2 on SMAD signalling

• Published in: PloS one Vol. 12; no. 5; p. e0178158
• Main Authors: Aquino-Martínez, Rubén, Artigas, Natalia, Gámez, Beatriz, Rosa, José Luis, Ventura, Francesc
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25-05-2017; Public Library of Science (PLoS)
• Subjects: 1-Phosphatidylinositol 3-kinase; Adherent cells; AKT protein; Alveolar bone; Amplification; Animal models; Animals; Antigenicity; Arches; Assaying; Attachment; Biochemistry; Biocompatibility; Biology and Life Sciences; Biomaterials; Biotechnology; Bone biomaterials; Bone growth; Bone healing; Bone marrow; Bone Marrow Cells - drug effects; Bone Marrow Cells - physiology; Bone Morphogenetic Protein 2 - physiology; Bone morphogenetic proteins; Bone remodeling; Bone turnover; Bones; Bones growth; Calci en l'organisme; Calcification; Calcium; Calcium - pharmacology; Calcium in the body; Cell adhesion; Cell Differentiation - drug effects; Cell Differentiation - physiology; Cells (biology); Cellular signal transduction; Collagen; Creixement dels ossos; Cèl·lules mare; Defects; Degradation; Degradation products; Differentiation; Engineering; Engineering and Technology; Exposure; Fragmentation; Gene expression; Gene Expression Profiling; Genetic aspects; Glial stem cells; Growth factors; Hay; Homeostasis; Hydroxyapatite; Inactivation; Kinases; Laminar flow; Media; Mesenchymal stem cells; Mesenchymal Stromal Cells - drug effects; Mesenchymal Stromal Cells - physiology; Mice; Mice, Inbred BALB C; Neural stem cells; Ossificació; Ossification; Osteoblasts - drug effects; Osteoblasts - physiology; Osteogenesis; Osteogenesis - drug effects; Osteogenesis - physiology; Osteoprogenitor cells; Pharmacology; Physiological aspects; Physiology; Plates (structural members); Potassium; Propagation; Proteins; Regulations; Research and Analysis Methods; Shear stress; Signal transduction; Signal Transduction - drug effects; Signal Transduction - physiology; Skeletogenesis; Smad Proteins - physiology; Stem cells; Strontium; Surgical implants; Temperature effects; Tissue engineering; Tissue Scaffolds; Transcription factors; Transducció de senyal cel·lular; Vertebrates; Vertical orientation; Spain
• DOI: 10.1371/journal.pone.0178158
• EISSN: 1932-6203

Understanding the molecular events that regulate osteoblast differentiation is essential for the development of effective approaches to bone regeneration. In this study, we analysed the osteoinductive properties of extracellular calcium in bone marrow-derived mesenchymal stem cell (BM-MSC) differentiation. We cultured BM-MSCs in 3D gelatin scaffolds with Ca2+ and BMP-2 as osteoinductive agents. Early and late osteogenic gene expression and bone regeneration in a calvarial critical-size defect model demonstrate that extracellular Ca2+ enhances the effects of BMP-2 on Osteocalcin, Runx2 and Osterix expression and promotes bone regeneration in vivo. Moreover, we analysed the molecular mechanisms involved and observed an antagonistic effect between Ca2+ and BMP-2 on SMAD1/5, ERK and S6K signalling after 24 hours. More importantly, a cooperative effect between Ca2+ and BMP-2 on the phosphorylation of SMAD1/5, S6, GSK3 and total levels of β-CATENIN was observed at a later differentiation time (10 days). Furthermore, Ca2+ alone favoured the phosphorylation of SMAD1, which correlates with the induction of Bmp2 and Bmp4 gene expression. These data suggest that Ca2+ and BMP-2 cooperate and promote an autocrine/paracrine osteogenic feed-forward loop. On the whole, these results demonstrate the usefulness of calcium-based bone grafts or the addition of exogenous Ca2+ in bone tissue engineering.