title: The effect of endothelin-1 on nuclear factor kappa B in macrophages.
abstract: Nuclear factor kappaB (NF-kappaB) is a transcriptional factor which may be pivotal in the pathogenesis of atherosclerosis. Endothelin-1 (ET-1) is a peptide with proatherogenic properties. We hypothesized that ET-1 may act through activation of NF-kappaB and degradation of IkappaB-alpha, the cytosolic inhibitor of NF-kappaB activation, to create an atherogenic environment. The human monocytic cell line THP-1 was stimulated with ET-1 +/- the ET antagonist, BQ788 and the proteosome inhibitor, PSI. LPS was used as a positive control. Gel shift assays for NF-kappaB activity and Western blot analysis for IkappaB-alpha were performed. Both LPS and ET-1 led to activation of NF-kappaB in nuclear extracts [3.4 +/- 0.45 (LPS) and 2.9 +/- 0.26 (ET-1) fold increase in Arbitrary Densitometric Units (ADU) compared with negative control (P < 0.005 in both cases)]. In the presence of the ETB antagonist, BQ788, NF-kappaB activation was attenuated and not different from control (1.7 +/- 0.24 fold DU compared with negative control; P = NS). In addition, both LPS and ET-1 mediated NF-kappaB activation were attenuated by preincubation with the proteosome inhibitor, PSI (1.3 +/- 0.58 and 1.1 +/- 0.3 fold increase in ADU compared with negative control respectively). Both LPS and ET-1 led to a decrease in the amount of IkappaB-alpha present in the THP-1 cytoplasmic extracts (2.1 +/- 1.5% and 54 +/- 15.7% of ADU vs negative control (P < 0.05). NF-kappaB is activated by ET-1 in human THP-1 monocytes. This data supports a role for the ETs in the development of inflammation in the vessel wall in atherosclerosis.
authors.affiliation: Division of Internal Medicine and Cardiovascular Diseases, Mayo Clinic and Foundation, 200 First Street SW, Rochester, Minnesota 55905, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Wilson
authors.forename: R D
authors.initials: RD
authors.lastname: Simari
authors.forename: A
authors.initials: A
authors.lastname: Lerman
mesh_terms: D000959:Antihypertensive Agents / Q000494:pharmacology; D001161:Arteriosclerosis / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003546:Cysteine Endopeptidases; D003593:Cytoplasm / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D019332:Endothelin-1 / Q000494:pharmacology*; D006801:Humans; D020672:I-kappa B Proteins; D007249:Inflammation / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D009000:Monocytes / Q000378:metabolism; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry; D010880:Piperidines / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding
chemical_list: D000959:Antihypertensive Agents; D004268:DNA-Binding Proteins; D019332:Endothelin-1; D020672:I-kappa B Proteins; D009097:Multienzyme Complexes; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D009842:Oligopeptides; D010455:Peptides; D010880:Piperidines; D000072000:NF-KappaB Inhibitor alpha; C086539:BQ 788; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex