Autocrine-paracrine role of endothelin-1 in the regulation of aldosterone synthase expression and intracellular Ca2+ in human adrenocortical carcinoma NCI-H295 cells.
The role played by endothelin (ET-1) and its receptor subtypes A and B (ET(A) and ET(B)) in the functional regulation of human NCI-H295 adrenocortical carcinoma cells has been investigated. Reverse transcription-PCR with primers specific for prepro-ET-1, human ET-1 converting enzyme-1, ET(A), and ET(B) complementary DNAs consistently demonstrated the expression of all genes in NCI-H295 cells. The presence of mature ET-1 and both its receptor subtypes was confirmed by immunocytochemistry and autoradiography, respectively. Aldosterone synthase (AS) messenger RNA was also detected in NCI-H295 cells, and AS gene expression was enhanced by both ET-1 and the specific ET(B) agonist IRL-1620; this effect was not inhibited by either the ET(A) antagonist BQ-123 or the ET(B) antagonist BQ-788. A clear-cut increase in the intracellular Ca2+ concentration in NCI-H295 cells in response to ET(B), but not ET(A), activation was observed. In light of these findings, the following conclusions can be drawn: 1) NCI-H295 cells possess an active ET-1 biosynthetic pathway and are provided with ET(A) and ET(B) receptors; 2) ET-1 regulates in an autocrine/paracrine fashion the secretion of aldosterone by NCI-H295 cells by enhancing both AS transcription and raising the intracellular Ca2+ concentration; and 3) the former effect of ET-1 probably involves the activation of both receptor subtypes, whereas calcium response is exclusively mediated by the ET(B) receptor.
Rossi
G P
GP
Department of Clinical and Experimental Medicine, University of Padua Medical School, Padova, Italy. gprossi@ipdunidx.unipd.it
Albertin
G
G
Bova
S
S
Belloni
A S
AS
Fallo
F
F
Pagotto
U
U
Trevisi
L
L
Palù
G
G
Pessina
A C
AC
Nussdorfer
G G
GG
D000306:Adrenal Cortex Neoplasms / Q000737:chemistry* / Q000473:pathology / Q000503:physiopathology; D018268:Adrenocortical Carcinoma / Q000737:chemistry* / Q000473:pathology / Q000503:physiopathology; D016282:Aspartic Acid Endopeptidases / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D001345:Autoradiography; D001483:Base Sequence; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D019405:Cytochrome P-450 CYP11B2 / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology / Q000502:physiology*; D000072396:Endothelin-Converting Enzymes; D016232:Endothelins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D008666:Metalloendopeptidases; D009842:Oligopeptides / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011498:Protein Precursors / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D017466:Receptors, Endothelin / Q000032:analysis / Q000502:physiology; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D016232:Endothelins; D009842:Oligopeptides; D010880:Piperidines; D011498:Protein Precursors; D017466:Receptors, Endothelin; C086539:BQ 788; D019405:Cytochrome P-450 CYP11B2; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D000072396:Endothelin-Converting Enzymes; D002118:Calcium