title: Effects of trabecular calcium phosphate scaffolds on stress signaling in osteoblast precursor cells.
abstract: The objective of this research was to investigate stress-signaling patterns in response to two-dimensional (2-D) and three-dimensional (3-D) calcium phosphate (CP) materials using human embryonic palatal mesenchyme cells (HEPM, CRL-1486, ATCC, Manassas, VA), an osteoblast precursor cell line. Control discs and scaffolds were fabricated from hydroxyapatite and beta tri-CP ceramics. Phospho-specific antibody cell-based ELISA technique was utilized on members of the mitogen-activated protein kinase cascade including; the extracellular signal-regulated kinases (ERK1/2), p38, c-Jun N-terminal kinase (JNK), and the anti-apoptosis mediator protein kinase B (AKT). Quantification of these signals was evaluated during the early attachment phase of osteoblast precursor cells. In this study, it was observed that 3-D CP scaffolds significantly activated the stress mediators p38 and JNK but not ERK1/2. This signal trend was matched with an up-regulation in AKT, suggesting the ability of cells to manage high stress signals in response to 3-D CP architecture and that 3-D CP scaffolds are necessary for studies simulating a natural trabecular bone organization. The absence of these signals in 2-D CP surfaces indicated the importance of local architecture conditions on cell stress response. It was concluded from this study that osteoblast precursor cells cultured in 3-D CP scaffolds experience greater stress-signaling patterns when compared to 2-D CP surfaces.
authors.affiliation: University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Appleford
authors.forename: Sunho
authors.initials: S
authors.lastname: Oh
authors.forename: Judith A
authors.initials: JA
authors.lastname: Cole
authors.forename: David L
authors.initials: DL
authors.lastname: Carnes
authors.forename: Myunghyun
authors.initials: M
authors.lastname: Lee
authors.forename: Joel D
authors.initials: JD
authors.lastname: Bumgardner
authors.forename: Warren O
authors.initials: WO
authors.lastname: Haggard
authors.forename: Joo L
authors.initials: JL
authors.lastname: Ong
mesh_terms: D001672:Biocompatible Materials / Q000378:metabolism / Q000494:pharmacology; D002130:Calcium Phosphates / Q000494:pharmacology*; D002448:Cell Adhesion; D002470:Cell Survival; D002478:Cells, Cultured; D017886:Durapatite / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008159:Lumbar Vertebrae / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013234:Stem Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D017886:Durapatite; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C018392:tricalcium phosphate