Cardiotrophin-1 induces interleukin-6 synthesis in human umbilical vein endothelial cells.
In patients with chronic heart failure (CHF) increased plasma concentrations of proinflammatory cytokines are found. For example, the plasma interleukin-6 (IL-6) concentration correlates with disease severity. Beside IL-6 cardiotrophin-1 (CT-1), a member of the IL-6 superfamily, is also increased in CHF. We examined whether CT-1 is able to induce IL-6 in human umbilical vein endothelial cells (HUVEC) and characterised the underlying pathway. IL-6 mRNA was determined by real-time PCR and by RT-PCR in HUVEC which were stimulated with different CT-1 concentrations and for different time periods. IL-6 concentration in the supernatant was determined by ELISA. For the pathway determination following inhibitors were used: piceatannol (signal transducer and activation of transcription (STAT)3 phosphorylation), wortmannin (phosphatiylinositol 3-kinase (PI3K)), SB203580 (p38 mitogen-activated protein kinase (MAPK)), AG490 (Janus kinase (JAK)2), PD98059 (mitogen-activated protein kinase kinase (MEK) 1/2), parthenolide (nuclear factor kappaB) and cycloheximide (protein biosynthesis). CT-1 caused a concentration- and time-dependent increase in IL-6 mRNA in HUVEC with a maximal induction seen after 6 h (2-fold compared to control) with 100 ng/ml CT-1. In the supernatant of HUVEC a concentration- and time-dependent increase of IL-6 protein was found. A maximum effect with 100 ng/ml CT-1 was found after 24 h (11-fold compared to control). AG490, SB203580, piceatannol, parthenolide and cycloheximide inhibit CT-1 induced IL-6 mRNA and protein expression whereas wortmannin and PD98059 did not inhibit IL-6 expression. CT-1 induced both IL-6 mRNA and protein in a concentration- and time-dependent manner in HUVEC. The underlying pathway includes activation of JAK2, STAT3, p38 and NFkappaB. CT-1 induced IL-6 expression and requires protein synthesis and IL-6 is not stored intracellularly. We speculate that in CHF CT-1 might be in part responsible for increased IL-6 plasma concentrations. Modulation of the CT-1 pathway may be a further strategy in CHF treatment.
Fritzenwanger
Michael
M
Department of Internal Medicine I, Division of Cardiology, Friedrich-Schiller-University Jena, Erlanger Allee 101, 07740 Jena, Germany. Michael.Fritzenwanger@med.uni-jena.de
Meusel
Katharina
K
Foerster
Martin
M
Kuethe
Friedhelm
F
Krack
Andreas
A
Figulla
Hans R
HR
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D016207:Cytokines / Q000276:immunology / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D053614:Janus Kinase 2 / Q000037:antagonists & inhibitors; D007700:Kinetics; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors; D012717:Sesquiterpenes / Q000494:pharmacology; D013267:Stilbenes / Q000494:pharmacology; D020032:Tyrphostins / Q000494:pharmacology; D014470:Umbilical Cord / Q000166:cytology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
D000911:Antibodies, Monoclonal; D016207:Cytokines; D004791:Enzyme Inhibitors; D007093:Imidazoles; D015850:Interleukin-6; D016328:NF-kappa B; D011725:Pyridines; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D012717:Sesquiterpenes; D013267:Stilbenes; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; C002669:parthenolide; C041525:3,3',4,5'-tetrahydroxystilbene; D003513:Cycloheximide; C092073:cardiotrophin 1; C507924:JAK2 protein, human; D053614:Janus Kinase 2; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580