title: Protein composition of plasminogen activator inhibitor type 1-derived endothelial microparticles.
abstract: Endothelial microparticles (EMPs) are small vesicles released from the plasma membrane of endothelial cells in response to cell injury, apoptosis, or activation. Low levels of MPs are shed into the blood from the endothelium, but in some pathologic states, the number of EMPs is elevated. The mechanism of MP formation and the wide-ranging effects of elevated EMPs are poorly understood. Here, we report the protein composition of EMPs derived from human umbilical cord endothelial cells stimulated with plasminogen activator inhibitor type 1 (PAI-1). Two-dimensional gel electrophoresis followed by mass spectrometry identified 58 proteins, of which some were verified by Western blot analysis. Gene Ontology database searches revealed that proteins identified on PAI-1-derived EMPs are highly diverse. Endothelial microparticles are composed of proteins from different cellular components that exhibit multiple molecular functions and are involved in a variety of biological processes. Important insight is provided into the generation and protein composition of PAI-1-derived EMPs.
authors.affiliation: Department of Surgery, Medical College of Wisconsin and Children's Research Institute, Milwaukee, WIsconsin 53226, USA.
authors.forename: Tara L
authors.initials: TL
authors.lastname: Sander
authors.forename: Jing-Song
authors.initials: JS
authors.lastname: Ou
authors.forename: John C
authors.initials: JC
authors.lastname: Densmore
authors.forename: Sushma
authors.initials: S
authors.lastname: Kaul
authors.forename: Isaac
authors.initials: I
authors.lastname: Matus
authors.forename: Simon
authors.initials: S
authors.lastname: Twigger
authors.forename: Brian
authors.initials: B
authors.lastname: Halligan
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Greene
authors.forename: Kirkwood A
authors.initials: KA
authors.lastname: Pritchard
authors.forename: Keith T
authors.initials: KT
authors.lastname: Oldham
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007525:Isoelectric Focusing; D017395:Plasminogen Activator Inhibitor 1 / Q000494:pharmacology*; D011506:Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D011506:Proteins