Effects of cadmium on cell viability, trophoblastic development, and expression of low density lipoprotein receptor transcripts in cultured human placental cells

Previously, we have demonstrated that cadmium inhibits progesterone release in cultured human trophoblast cells. In the present study, we investigated potential mechanism(s) by which cadmium may elicit this effect. Cytotropho blasts were obtained via enzymatic dispersion, purified by density gradient centrifugation, and cultured with increasing concentrations of cadmium. Ca dmium-induced suppression of progesterone release seemed to be independent of cell death, as no significant decline in viability was observed with cad mium treatment. Further, immunocytochemical localization of cellular bounda ries and nuclei indicated approximately 94% syncytial maturity was attained by both untreated and cadmium-treated cells, demonstrating that cadmium di d not inhibit syncytial development. However, the abundance of LDL receptor (LDL-R) mRNA transcripts, as determined by competitive RT-PCR, was reduced (P < 0.05) by cadmium exposure in an apparent dose-dependent manner. Thus, the LDL-R, by which cholesterol substrate is supplied to the syncytiotroph oblast, is one site at which cadmium may interfere with placental progester one production. (C) 1999 Elsevier Science Inc. All rights reserved.