title: Involvement of mitogen-activated protein kinase pathways in Staphylococcus aureus invasion of normal osteoblasts.
abstract: Staphylococcus aureus invades osteoblasts and can persist in the intracellular environment. The present study examined the role of osteoblast mitogen-activated protein kinase (MAPK) pathways in bacterial invasion. S. aureus infection of normal human and mouse osteoblasts resulted in an increase in the phosphorylation of the extracellular signal-regulated protein kinases (ERK 1 and 2). This stimulation of ERK 1 and 2 correlated with the time course of S. aureus invasion, and bacterial adherence induced the MAPK pathway. ERK 1 and 2 phosphorylation was time and dose dependent and required active S. aureus gene expression for maximal induction. The nonpathogenic Staphylococcus carnosus was also able to induce ERK 1 and 2 phosphorylation, albeit at lower levels than S. aureus. Phosphorylation of the stress-activated protein kinases was increased in both infected human and mouse osteoblasts; however, the p38 MAPK pathway was not activated in response to S. aureus. Finally, the transcription factor c-Jun, but not Elk-1 or ATF-2, was phosphorylated in response to S. aureus infection.
authors.affiliation: Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Ellington
authors.forename: A
authors.initials: A
authors.lastname: Elhofy
authors.forename: K L
authors.initials: KL
authors.lastname: Bost
authors.forename: M C
authors.initials: MC
authors.lastname: Hudson
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002478:Cells, Cultured; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020935:MAP Kinase Signaling System; D051379:Mice; D008807:Mice, Inbred BALB C; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010006:Osteoblasts / Q000378:metabolism* / Q000382:microbiology*; D010766:Phosphorylation; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D013211:Staphylococcus aureus / Q000254:growth & development / Q000472:pathogenicity*; D014466:Ultraviolet Rays
chemical_list: D016755:Proto-Oncogene Proteins c-jun; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases