Identification of specific serum proteins synthesized de novo by monolayer cultures of glandular cells of gestational endometrium

Abstract

Monolayer cell cultures (n = 3) of glandular epithelium of gestational endometrium obtained from three apparently healthy women undergoing elective termination of pregnancy (7-9 weeks gestation) were established. De novo synthesis of eight serum proteins (albumin, alpha 1-antitrypsin, ceruloplasmin, beta-lipoprotein, alpha 2-macroglobulin, fibronectin and complement factors C3 and C4) was demonstrated by the incorporation of radiolabelled substrate ([35S]methionine) employing autoradiography (AR) in combination with crossed immunoelectrophoresis (XIE), referred to as ARXIE, and line immunoelectrophoresis (LIE), referred to as ARLIE. By contrast, there was no evidence for de novo synthesis of IgA, haptoglobin and orosomucoid. Our findings suggest that the gestational endometrium may contribute to the production of several proteins considered to be synthesized and secreted mainly by the liver and reticulo-endothelial system. The simple techniques used here to identify the de novo synthesis of human serum proteins could be applied to investigate protein synthesis by a wide range of tissues and cells.