A role for increased mRNA stability in the induction of endothelin-1 synthesis by lipopolysaccharide.
An association exists between infection and cardiovascular diseases, including atherosclerosis, stroke and myocardial infarction. This may involve endothelin-1 (ET-1) which has been implicated in these and other vascular pathologies. ET-1 synthesis is controlled primarily by the level of its mRNA and numerous stimuli, including infection, lead to elevated ET-1 levels. Here, we have investigated the regulation of ET-1 release and preproET-1 (ppET-1) mRNA in bovine aortic endothelial cells by lipopolysaccharide (LPS). ET-1 release from bovine aortic endothelial cells was stimulated by LPS and reporter gene assays implicated LPS-induced ppET-1 transcription. However, changes in transcription were modest compared to increases in ET-1 synthesis. Therefore, ppET-1 mRNA levels were measured by real-time reverse transcription-polymerase chain reaction. The effect of LPS on ppET-1 mRNA levels was more marked than on transcription (1.2-fold increase in transcription vs. 5.5-fold increase in ppET-1 mRNA). Analysis of ppET-1 mRNA stability by real-time reverse transcription-polymerase chain reaction showed that LPS increased its half-life by approximately 2-fold. Thus, upregulated ppET-1 mRNA and hence increased ET-1 synthesis may be due to both increased transcription and reduced mRNA degradation. These effects of LPS on mRNA stability may be a key mechanism in vascular pathologies through which many proteins are induced in response to infection.
Douthwaite
Julie A
JA
Department of Experimental Therapeutics, William Harvey Research Institute, St Bartholomew's and the Royal London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, EC1M 6BQ, London, UK. j.a.douthwaite@qmul.ac.uk
Lees
Delphine M
DM
Corder
Roger
R
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016328:NF-kappa B / Q000502:physiology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000737:chemistry*
D019332:Endothelin-1; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger