Change of endothelin receptor subtype in the MEG-01 human megakaryoblastic cell line

• Published in: European journal of pharmacology Vol. 344; no. 2; pp. 307 - 312
• Main Authors: Hamroun, Dalil, Mathieu, Marie-Noelle, Chevillard, Claude
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.03.1998; Elsevier
• Subjects: Biological and medical sciences; Calcium - metabolism; Cell Line; Cell receptors; Cell structures and functions; Endothelin receptor subtype; Endothelins - pharmacology; Fundamental and applied biological sciences. Psychology; Humans; MEG-01 cell line; Megakaryocytes - metabolism; Miscellaneous; Molecular and cellular biology; Oligopeptides - pharmacology; Peptide Fragments - pharmacology; Piperidines - pharmacology; Platelet; Receptors, Endothelin - drug effects; Receptors, Endothelin - metabolism; Reverse transcriptase–polymerase chain reaction; Viper Venoms - pharmacology; MEG-01 cell line; Endothelin receptor subtype; Platelet; Reverse transcriptase–polymerase chain reaction; Human; Megakaryocytopoiesis; Endothelin; Peptide hormone; In vitro; Precursor; Cell subpopulation; Blood cell; Biological fixation; Calcium ion; Established cell line; Peptidergic receptor; Vasoconstrictor agent; Subtype
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/S0014-2999(97)01594-X

The aim of this investigation was to determine whether the endothelin receptor subtype of a megakaryoblastic cell line (MEG-01) changes during culture passages as cells undergo maturation and differentiation. On early-passage cells, binding of [ 125 I ]endothelin-1 was completely inhibited by 1 μM BQ 123 ( cyclo-[ d-tryptophanyl- d-aspartyl–prolyl- d-valyl–leucyl]), but not by sarafotoxin 6C. Also the endothelin-1-enhancing effect on [Ca 2+] i was prevented by BQ 123, whereas sarafotoxin 6C had no effect on [Ca 2+] i. In late-passage cells, endothelin ET B analogs, unlike endothelin ET A analogs, competed with binding of [ 125 I ]endothelin-1. Endothelin ET B receptor agonists increased [Ca 2+] i while the endothelin-1-induced response was inhibited by BQ 788 ([ N-[(2 R,6 S)-2,6-dimethyl-piperidinocarbonyl]-4-methyl- d-leucyl]-[ N ω -(methoxycarbonyl)- d-tryptophanyl]- d-norleucine), but not by BQ 123, although both endothelin ET A and ET B receptor mRNAs were expressed, as shown by reverse transcriptase–polymerase chain reaction. These results demonstrate that in MEG-01 cells switch from expression of endothelin ET A to expression of ET B receptors during culture. The data also suggest that late-passage MEG-01 cells look like platelets, in terms of endothelin receptor subtype.