engleski

Self-regulation of the endothelin receptor system in choriocarcinoma cells

The human trophoblast secretes endothelin-l (ET-1) and expresses ET receptors. The present study tested whether the transformed BeWo, JAR and JEG-3 choriocarcinoma cells: (1) secrete endothelin-l (ET-I) ; (2) express both ET-A and ET-B receptor subtypes ; and (3) have the potential to allow for autologous regulation of ET-receptor proteins. The cells were cultured for 24/48 h with or without 10% FCS and, in experiments on receptor regulation, with ET-I (5-20 nM and 10 CIM). ET-I secretion was measured by RIA and receptor levels by immunoblotting. All cell types secreted ET-1 albeit at different levels and sensitivity to FCS. All cell lines expressed both ET-A (JEC-3 > BeWo = JAR) and ET-B (JEG-3 = JAR > BeWo) receptor subtypes, which could be up- and downregulated depending on ET-I concentration, culture time and FCS presence. It is concluded that BeWo, JAR and JEG-3 choriocarcinoma cells secrete ET-1 and express both ET-A and ET-B receptor subtypes. The receptor levels can be regulated by ET-I. This provides the molecular basis for an autocrine system with the potential of autologous regulation of yet unidentified ET-l-induced functions.

Endothelin-1; Receptor; Regulation; Secretion; Choriocarcinoma

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