Detection and synthesis of a progestagen-dependent protein in human endometrium

Abstract

Immunologiocal and biochemical methods were employed to demonstrate the presence of progestagen-dependent proteins in human endometrium. Cytosols were prepared from proliferative and secretory phase endometria of cycling women, from decidua and decidua-rich tissues of women in early pregnancy and from decidua of tubal pregnancy. Antisera were raised in rabbits against the antigens of decidua of tubal pregnancy and decidua-rich tissues. Immunoelectrophoresis, Ouchterlony's immunodiffusion test and polyacrylamide gel electrophoresis using native gels revealed 2 antigenic proteins, designated antigens A and B, in secretory endometria, decidua-rich tissues, decidua, and in decidua of tubal pregnancy. However, only 1 antigenic protein was detected by SDS-gel electrophoresis: antigens A and B may therefore be two different proteins or two forms of a single protein. The antigens could not be detected in non-pregnancy sera or in term placentae. Double isotopic labelling (incubation of tissues with [3H]- and [14C]leucine) followed by protein fractionation methods were used to compare the in-vitro synthesis rates of antigens in poroliferative tissues with those in decidua or secretory endometria. The rate of synthesis of antigens A and B was markedly higher in the decidua and secretory endometria than in the proliferative endometria. We conclude, therefore, that during progestagen-dependent transformation of proliferative phase endometria into secretory endometria and decidua in women, there is a selective stimulation of at least one species of pregnancy-associated protein.

Immunochemical detection and characterization of pregnancy-associated endometrial 1- and 2-globulins secreted by human endometrium and decidua

“…Consistently these studies have demonstrated the synthesis of a protein, of molecular weight under reducing conditions of 50-55 000, associated with the secretory phase endometrium or in-vitro exposure of the endometrium to progesterone (Hirsch, Ferguson & King, 1977; O'Grady, Bell, Govan & Black, 1978;Shapiro & Forbes, 1978;Iacobelli et ai, 1981). Examination of the synthesis of cytosolic proteins of pregnancy endometrium has also detected a "progesteronedependent endometrial protein" ("PEP": Joshi, Ebert & Swartz, 1980a) and although secretion of this or the former protein has not been demonstrated the presence of immunochemically reactive PEP in amniotic fluid (Joshi, Smith & Stokes, 1980b) and blood (Joshi, Bank & Szarowski, 1981) suggests that PEP is secreted.…”

Effect of progesterone on proteins vectorially secreted by glandular epithelial cells of guinea-pig endometrium: modulation by homologous stroma

“…This progesterone-dependent protein, called PP14 (Rutanen et al, 1987), or o2-PEG (Bell et al, 1985) or progestagen-dependent endometrial protein (Joshi et al, 1980), related to ß-lactoglobulins, could function as a ligand-carrier (Bell et al, 1987). In the same way, a progesterone-dependent protein of 28 kDa, with a cathepsin L activity (Jaffe et al, 1989), is secreted by cat endometrial explants (Boomsma and Verhage, 1987 (Mossman, 1987; Kimberly and Thornburg, 1989;Beier et al, 1991 (Cunha et al, 1985;Inaba et al, 1988;Hohn et al, 1989;Lavia and Larson, 1991).…”

Immunohistochemical markers of uterine receptivity in the human endometrium

“…The major secretory protein of luteal phase endometrium has many names, but was first referenced as progestogen-associated endometrial protein (PEP) by Joshi et al in 1980Joshi et al in (1980a. PEP was later found to be identical to PP14, a protein described by Bohn et al (1982) initially thought to be a placental protein, and a2-PEG or EP-15 (Bell and Bohn, 19861, a protein characterized by Bell from first trimester endometrium (1986).…”