title: Synergistic effect of Wnt modulatory small molecules and an osteoinductive ceramic on C2C12 cell osteogenic differentiation.
abstract: Although osteoinductive ceramics can induce osteoblast differentiation in vitro and bone regeneration in vivo, their effects rely solely on the limited number of endogenous stem cells. More recently, ceramic carriers seeded with culture-expanded stem cells have been reported as implants capable of in vivo bone formation. However, effective and safe signaling agents that promote cell differentiation to the osteogenic lineage are still needed. In the present report, two osteogenic small-molecules THQ-1a and PP-9 were identified by testing a series of compounds for Runx2 and BMP2 expression in C2C12 cells. Compounds THQ-1a and PP-9 modulated Wnt signaling and enhanced the expression of molecular markers of osteoblast differentiation. To probe the utility of these compounds for use with ceramic cell implants, the effect of THQ-1a and PP-9 on C2C12 cell osteogenic differentiation was investigated in the presence of a tricalcium phosphate (TCP) ceramic. The effect of THQ-1a and PP-9 on markers such as Osteocalcin and Collagen I was significantly increased in the presence of TCP ceramic. Additionally, THQ-1a or PP-9 in the presence of TCP ceramic gave a synergistic increase in alkaline phosphatase activity in the differentiation of C2C12 cells. Taken together, the results suggest an approach to directing cell lineage commitment for bone regeneration by the application of small-molecule osteogenic agents to cells in the presence of osteoinductive ceramics.
authors.affiliation: The Human BioMolecular Research Institute, San Diego, CA 92121, USA.
authors.forename: Sigeng
authors.initials: S
authors.lastname: Chen
authors.affiliation: The Human BioMolecular Research Institute, San Diego, CA 92121, USA. Electronic address: dryan@hbri.org.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Ryan
authors.affiliation: The Human BioMolecular Research Institute, San Diego, CA 92121, USA.
authors.forename: Mary A
authors.initials: MA
authors.lastname: Dwyer
authors.affiliation: The Human BioMolecular Research Institute, San Diego, CA 92121, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Cashman
mesh_terms: D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D002130:Calcium Phosphates / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002516:Ceramics; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D004357:Drug Synergism; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects
chemical_list: D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D050659:Core Binding Factor Alpha 1 Subunit; C018392:tricalcium phosphate
keywords: C2C12; Mesenchymal stromal cells; Osteogenesis; Small molecules; Tricalcium phosphate ceramic; Wnt