V L Baker1, V A Chao, J T Murai, C J Zaloudek, R N Taylor. 1. W. M. Keck Laboratory of Reproductive and Developmental Molecular Biology, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, USA.
Abstract
OBJECTIVE: To identify and characterize estrogen receptors in human umbilical vascular tissues and in cultured cells derived from the human umbilical vein. METHODS: Human umbilical vein endothelial (HUVE) and human umbilical vein smooth muscle (HUVSM) cells were isolated. Immunohistochemical, radioligand binding. Western immunoblotting, and reverse transcription-polymerase chain reaction (RT-PCR) methods were used to detect estrogen receptors in vascular tissues and in cells derived from the umbilical cord. RESULTS: Estrogen receptor protein was not detected in either umbilical vessel tissue or in isolated HUVE or HUVSM cells. Messenger RNAs for the classic estrogen receptor (alpha) and estrogen receptor beta isoforms also were undetectable by RT-PCR. CONCLUSION: These findings suggest that the effects of estradiol observed in this widely used vascular model are mediated by very low concentrations of receptors that evade standard methods of detection. Alternatively, this steroid may affect umbilical vascular cells through mechanisms that do not involve the classic genomic estrogen-receptor pathway.
OBJECTIVE: To identify and characterize estrogen receptors in human umbilical vascular tissues and in cultured cells derived from the human umbilical vein. METHODS:Human umbilical vein endothelial (HUVE) and human umbilical vein smooth muscle (HUVSM) cells were isolated. Immunohistochemical, radioligand binding. Western immunoblotting, and reverse transcription-polymerase chain reaction (RT-PCR) methods were used to detect estrogen receptors in vascular tissues and in cells derived from the umbilical cord. RESULTS: Estrogen receptor protein was not detected in either umbilical vessel tissue or in isolated HUVE or HUVSM cells. Messenger RNAs for the classic estrogen receptor (alpha) and estrogen receptor beta isoforms also were undetectable by RT-PCR. CONCLUSION: These findings suggest that the effects of estradiol observed in this widely used vascular model are mediated by very low concentrations of receptors that evade standard methods of detection. Alternatively, this steroid may affect umbilical vascular cells through mechanisms that do not involve the classic genomic estrogen-receptor pathway.