Thrombin-induced regulation of CD95(Fas) expression in the N9 microglial cell line: evidence for involvement of proteinase-activated receptor(1) and extracellular signal-regulated kinase 1/2.
Microglia are the immune cells of the CNS. Brain injury triggers phenotypic changes in microglia including regulation of surface antigens. The serine proteinase alpha-thrombin can induce profound changes in neural cell physiology via cleavage of proteinase-activated receptors (PARs). We recently demonstrated that pharmaceutical-grade recombinant human alpha-thrombin (rh-thr) induces a restricted set of proteolysis-dependent changes in microglia. CD95(Fas) is a cell-death receptor that is up-regulated in microglia by inflammatory stimuli. Here we characterized the effect of rh-thr on CD95(Fas) expression in the N9 microglial cell line. Dose-response and time course studies demonstrated maximal effects at 100 U/ml and 24 h, respectively. Regulation of expression was seen at both the surface protein and steady-state mRNA levels. The rh-thr-induced effects were mimicked by PAR(1) agonist peptides and blocked by pharmacologic inhibitors selective for extracellular signal-regulated kinase 1/2 (ERK 1/2). Rh-thr also induced a rapid and sustained phosphorylation of ERK 1/2. Thrombin-induced regulation of CD95(Fas) could modulate the neuroinflammatory response in a variety of neurological disorders.
Weinstein
Jonathan R
JR
Department of Neurology, School of Medicine, University of Washington, Box 356465, 1959 NE Pacific Street, Seattle, WA 98195-6465, USA. jweinste@u.washington.edu
Zhang
Matthew
M
Kutlubaev
Mansur
M
Lee
Richard
R
Bishop
Caroline
C
Andersen
Henrik
H
Hanisch
Uwe-Karsten
UK
Möller
Thomas
T
D000818:Animals; D002460:Cell Line; D006801:Humans; D007700:Kinetics; D051379:Mice; D017628:Microglia / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000502:physiology*; D010766:Phosphorylation; D044463:Receptor, PAR-1 / Q000819:agonists / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology / Q000502:physiology*; D015854:Up-Regulation; D019014:fas Receptor / Q000096:biosynthesis*
D044463:Receptor, PAR-1; D011994:Recombinant Proteins; D019014:fas Receptor; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D013917:Thrombin