title: Signal transduction pathways involved in mechanical regulation of HB-GAM expression in osteoblastic cells.
abstract: Protein kinase C (PKC), protein kinase A (PKA), prostaglandin synthesis, and various mitogen-activated protein kinases (MAPKs) have been reported to be activated in bone cells by mechanical loading. We studied the involvement of these signal transduction pathways in the downregulation of HB-GAM expression in osteoblastic cells after cyclic stretching. Specific antagonists and agonists of these signal transduction pathways were added to cells before loading and to non-loaded control cells. Quantitative RT-PCR was used to evaluate gene expression. The data demonstrated that the extracellular signal-regulated kinase (ERK) 1/2 pathway, PKC, PKA, p38, and c-Jun N-terminal kinase MAPK participated in the mechanical downregulation of HB-GAM expression, whereas prostaglandin synthesis did not seem to be involved.
authors.affiliation: Institute of Orthopedic Research and Biomechanics, University of Ulm, Germany. astrid.liedert@uni-ulm.de
authors.forename: Astrid
authors.initials: A
authors.lastname: Liedert
authors.forename: Daniela
authors.initials: D
authors.lastname: Kaspar
authors.forename: Lutz
authors.initials: L
authors.lastname: Claes
authors.forename: Anita
authors.initials: A
authors.lastname: Ignatius
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism; D010006:Osteoblasts / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013314:Stress, Mechanical
chemical_list: D002352:Carrier Proteins; D016207:Cytokines; D009097:Multienzyme Complexes; C066845:pleiotrophin; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases