title: The extracellular adherence protein (Eap) of Staphylococcus aureus acts as a proliferation and migration repressing factor that alters the cell morphology of keratinocytes.
abstract: Staphyloccocus aureus is a major human pathogen and a common cause for superficial and deep seated wound infections. The pathogen is equipped with a large arsenal of virulence factors, which facilitate attachment to various eukaryotic cell structures and modulate the host immune response. One of these factors is the extracellular adherence protein Eap, a member of the "secretable expanded repertoire adhesive molecules" (SERAM) protein family that possesses adhesive and immune modulatory properties. The secreted protein was previously shown to impair wound healing by interfering with host defense and neovascularization. However, its impact on keratinocyte proliferation and migration, two major steps in the re-epithelialization process of wounds, is not known. Here, we report that Eap affects the proliferation and migration capacities of keratinocytes by altering their morphology and adhesive properties. In particular, treatment of non-confluent HaCaT cell cultures with Eap resulted in cell morphology changes as well as a significant reduction in cell proliferation and migration. Eap-treated HaCaT cells changed their appearance from an oblong via a trapezoid to an astral-like shape, accompanied by decreases in cell volume and cell stiffness, and exhibited significantly increased cell adhesion. Eap had a similar influence on endothelial and cancer cells, indicative for a general effect of Eap on eukaryotic cell morphology and functions. Specifically, Eap was found to interfere with growth factor-stimulated activation of the mitogen-activated protein kinase (MAPK) pathway that is known to be responsible for cell shape modulation, induction of proliferation and migration of epithelial cells. Western blot analyses revealed that Eap blocked the phosphorylation of extracellular signal-regulated kinase 1 and 2 (Erk1/2) in keratinocyte growth factor (KGF)-stimulated HaCaT cells. Together, these data add another antagonistic mechanism of Eap in wound healing, whereby the bacterial protein interferes with keratinocyte migration and proliferation.
authors.affiliation: Institute for Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Eisenbeis
authors.affiliation: Institute for Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Peisker
authors.affiliation: Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg/Saar, Germany.
authors.forename: Christian S
authors.initials: CS
authors.lastname: Backes
authors.affiliation: Institute for Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Bur
authors.affiliation: Clinic of Urology and Pediatric Urology, University of Saarland Hospital, Homburg/Saar, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Hölters
authors.affiliation: Experimental Physics, Saarland University, Saarbrücken, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Thewes
authors.affiliation: Department of Medical Biochemistry and Molecular Biology, Saarland University, Homburg/Saar, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Greiner
authors.affiliation: Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg/Saar, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Junker
authors.affiliation: Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg/Saar, Germany.
authors.forename: Eva C
authors.initials: EC
authors.lastname: Schwarz
authors.affiliation: Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg/Saar, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Hoth
authors.affiliation: Clinic of Urology and Pediatric Urology, University of Saarland Hospital, Homburg/Saar, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Junker
authors.affiliation: Institute of Biochemistry, Medical School, Justus-Liebig-University, Giessen, Germany.
authors.forename: Klaus T
authors.initials: KT
authors.lastname: Preissner
authors.affiliation: Experimental Physics, Saarland University, Saarbrücken, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Jacobs
authors.affiliation: Institute for Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Herrmann
authors.affiliation: Institute for Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany. Electronic address: markus.bischoff@uks.eu.
authors.forename: Markus
authors.initials: M
authors.lastname: Bischoff
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D042783:Endothelial Cells / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013211:Staphylococcus aureus / Q000472:pathogenicity*; D014945:Wound Healing / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; C444739:Eap-N protein, Staphylococcus aureus; D016601:RNA-Binding Proteins
keywords: Cell morphology; Eap; Keratinocytes; Migration; Proliferation; Staphylococcus aureus