On interaction of activated protein C with human aortic smooth muscle cells attenuating the secretory group IIA phospholipase A2 expression.
BACKGROUND
Pharmacological restriction of secretory group IIA phospholipase A(2) (sPLA(2)-IIA) expression is thought to be beneficial in the treatment of inflammatory diseases such as sepsis and septic shock. In this study we investigated the effects of activated protein C (APC) on sPLA(2)-IIA expression, phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, and on DNA-binding activities of nuclear factor-kappaB (NF-kappaB) and CCAAT box enhancer binding protein-beta (C/EBP-beta) in human aortic smooth muscle cells (HASMC).


METHODS
To achieve elevated sPLA(2)-IIA production as occurring during inflammation, HASMC were stimulated with interferon-gamma (IFN-gamma) alone and in combination with other inductors, thus modeling the strong sPLA(2)-IIA elevation by inflammation.


CONCLUSIONS
APC inhibited the stimulated expression of sPLA(2)-IIA in HASMC dose-dependently (1-300 nM). At the same time, APC increased the phosphorylation of ERK 1/2 and decreased NF-kappaB and C/EBP-beta DNA-binding activities in these cells, as compared with respective stimulated controls. Reverse transcriptase-polymerase chain reaction and cell-based ELISA reveal an endothelial protein C receptor (EPCR) expression in HASMC. Application of antibodies against EPCR and protease-activated receptor-1 (PAR-1) reduced the APC-induced ERK 1/2 activation and the treatment of cells with a PAR-1 antagonist diminished the sPLA(2)-IIA inhibition. The obtained results show that APC effectively suppresses the up-regulated sPLA(2)-IIA expression, which might contribute to the reported beneficial effects of APC in the treatment of severe inflammatory disorders.
Menschikowski
Mario
M
Institute of Clinical Chemistry and Laboratory Medicine, Technical University of Dresden, Medical Faculty Carl Gustav Carus, Dresden, Germany. menschik@rcs1.urz.tu-dresden.de
Hagelgans
Albert
A
Hempel
Ute
U
Lattke
Peter
P
Ismailov
Iskander
I
Siegert
Gabriele
G
D001011:Aorta / Q000502:physiology*; D001665:Binding Sites; D003331:Coronary Vessels / Q000201:enzymology*; D004730:Endothelium, Vascular / Q000201:enzymology; D004797:Enzyme-Linked Immunosorbent Assay; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007249:Inflammation / Q000201:enzymology; D007700:Kinetics; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D054497:Phospholipases A2, Secretory / Q000097:blood / Q000235:genetics*; D011486:Protein C / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics
D011486:Protein C; D012333:RNA, Messenger; D054497:Phospholipases A2, Secretory