title: Effect of 2-hydroxyethyl methacrylate on human pulp cell survival pathways ERK and AKT.
abstract: Previous investigations have revealed that dental monomers could affect intracellular pathways leading to cell survival or cell death. Mitogen-activated protein kinase (MAPK) and protein kinase B (AKT) might mediate cell responses as well as cell survival and apoptosis. The purpose of this study was to evaluate the effects of 2-hydroxyethyl methacrylate (HEMA) on the ERK1/2 and AKT pathways in human primary pulp fibroblasts (HPCs). HPCs were treated with various concentrations of HEMA, after which viability and reactive oxygen species levels were determined by flow cytometry with Annexin V-PI staining and 2,7-dichlorofluorescine diacetate, respectively. Whole-cell extracts were immunoblotted with anti-P-Akt or anti-P-ERK1/2. Cell viability decreased in a dose-dependent manner after HEMA exposure, showing a significant decrease with 10 mmol/L HEMA (p < .05). HEMA treatment resulted in a 4-fold increase in reactive oxygen species formation (p < .05). A short HEMA exposure (30-90 minutes) increased ERK1/2 phosphorylation, whereas a decrease in the AKT phosphorylation was observed. Selective inhibitors of the ERK (PD98059) and AKT (LY294002) pathways amplified HPC cell damage after HEMA exposure. Our findings demonstrated that HEMA exposure modulates the ERK and AKT pathways in different manners, and that in turn, they function in parallel to mediate pro-survival signaling in pulp cells subjected to HEMA cytotoxicity.
authors.affiliation: Department of Oral and Maxillofacial Sciences and Interdisciplinary Research Centre on Biomaterials (CRIB), University of Naples Federico II, Naples, Italy. gspagnuo@unina.it
authors.forename: Gianrico
authors.initials: G
authors.lastname: Spagnuolo
authors.forename: Vincenzo
authors.initials: V
authors.lastname: D'Antò
authors.forename: Rosa
authors.initials: R
authors.lastname: Valletta
authors.forename: Caterina
authors.initials: C
authors.lastname: Strisciuglio
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schmalz
authors.forename: Helmut
authors.initials: H
authors.lastname: Schweikl
authors.forename: Sandro
authors.initials: S
authors.lastname: Rengo
mesh_terms: D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003188:Composite Resins / Q000633:toxicity*; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008689:Methacrylates / Q000633:toxicity*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D019279:Resin Cements / Q000633:toxicity*
chemical_list: D003188:Composite Resins; D008689:Methacrylates; D017382:Reactive Oxygen Species; D019279:Resin Cements; C005044:hydroxyethyl methacrylate; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases