title: Proinflammatory changes in human umbilical cord vein endothelial cells can be induced neither by native nor by modified CRP.
abstract: The role of C-reactive protein (CRP) in atherosclerosis is controversial. It is not clear, either, if the presumed endothelium-activating effect of CRP resides in native CRP (nCRP) or in a conformational isoform of CRP known as modified CRP (mCRP). In the present study we evaluated and compared the effect of nCRP, recombinant modified CRP (rmCRP) and urea-modified CRP (umCRP) on human umbilical vein endothelial cells (HUVECs). CRP preparations were carefully analyzed by biochemical, immunological and cell biological methods in order to avoid endotoxin or sodium azide contamination as well as inappropriate conformational changes, which together had possibly been the main reason for the previously published controversial results. Neither nCRP nor mCRP showed significant cytotoxicity up to 100 microg ml(-1) at 24 h but high concentrations of CRPs induced cell death at 48 h. rmCRP but not nCRP nor umCRP showed membrane binding to HUVEC by confocal microscopy. However, none of the CRP forms induced intercellular cell adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin expression or IL-8 production. Monocyte chemotactic protein-1 production was weakly inhibited by high concentration of both nCRP and rmCRP, analyzed by sandwich ELISA. Neither nCRP nor mCRP could induce pro-inflammatory changes in the phenotype of HUVECs. Therefore, our present findings do not support the notion that different isoforms of CRP alone have significant effects on inflammation of the vessel wall via an interaction with endothelial cells (ECs), although one cannot exclude the possibility that there may be significant differences among various types of ECs in the response to CRP.
authors.affiliation: 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Melinda
authors.initials: M
authors.lastname: Oroszlán
authors.forename: Eszter
authors.initials: E
authors.lastname: Herczenik
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Rugonfalvi-Kiss
authors.forename: Anja
authors.initials: A
authors.lastname: Roos
authors.forename: Alma J
authors.initials: AJ
authors.lastname: Nauta
authors.forename: Mohamed R
authors.initials: MR
authors.lastname: Daha
authors.forename: Imre
authors.initials: I
authors.lastname: Gombos
authors.forename: István
authors.initials: I
authors.lastname: Karádi
authors.forename: László
authors.initials: L
authors.lastname: Romics
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Prohászka
authors.forename: George
authors.initials: G
authors.lastname: Füst
authors.forename: László
authors.initials: L
authors.lastname: Cervenak
mesh_terms: D050197:Atherosclerosis / Q000276:immunology; D002097:C-Reactive Protein / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000276:immunology*; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000276:immunology; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014471:Umbilical Veins / Q000166:cytology / Q000276:immunology*; D014508:Urea / Q000737:chemistry
chemical_list: D020033:Protein Isoforms; D011994:Recombinant Proteins; D014508:Urea; D002097:C-Reactive Protein