Gene expression of endothelin-1 (ET-1) and release of mature peptide by activated human neutrophils.
Polymorphonuclear neutrophils (PMNs) are only regarded as being involved in the cleavage of exogenous big endothelin-1 (ET-1) to the active peptide. The aims of the present study were to investigate whether PMNs may themselves express mRNA for prepro-ET-1 (pp-ET-1, a long precursor of 212 amino acids) and to determine the capacity of several PMN stimulants to modulate mRNA expression and the release of ET-1 in culture medium. PMNs, isolated from seven healthy adult volunteers, were stimulated with lipopolysaccharide (LPS, 0.25-10 microg/ml), or LPS (1 microg/ml) + phorbol myristate acetate (PMA, 10 ng/ml) or N-formyl-L-methionyl-L-leucyl-L-phenylalanine (f-MLP, 10(-5) M) or tumour necrosis factor-alpha (TNF-alpha, 50 IU/ml). They were found to express pp-ET-1 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Enzyme immunoassay (EIA) revealed low levels of ET-1 in the culture supernatants of PMNs stimulated for 3 h with LPS (10 microg/ml) and with LPS + PMA. Control unstimulated PMNs did not express pp-ET-1 mRNA. The local production of ET-1 by PMNs in vivo has significant implications in inflammatory diseases.
Cambiaggi
C
C
Institute of General Physiology, University of Siena, Siena, Italy.
Mencarelli
M
M
Muscettola
M
M
Grasso
G
G
D000328:Adult; D002478:Cells, Cultured; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D016232:Endothelins / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D018375:Neutrophil Activation / Q000235:genetics; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis
D019332:Endothelin-1; D016232:Endothelins; D010455:Peptides; D011498:Protein Precursors; D012333:RNA, Messenger