Estrogens regulate the release of Macrophage Migration Inhibitory Factor (MIF) by human chorionic villous explants

Aim: hormonal and cytokines factors acting locally at the maternal fetal interface are believed to play a major role in establishing the immune privilege of pregnancy. Numerous studies suggest that estrogens directly affect cellular function including cytokines production. Macrophage Migration Inhibitory Factor (MIF) is a key regulator of the inflammatory and immune responses. We recently demonstrated that MIF is abundantly expressed in first trimester human trophoblast, declined at 11-12 weeks remaining stable until term. Since reports on mice have shown that Estrogens play an important role of macrophage MIF, we investigated the link between Estrogens and the cytokine MIF in human placenta. Methods: chorionic villous explants were exposed to medium containing 17-Estradiol (E2) at concentrations varying from 10-5 to 10-12 M or vehicle alone (Ethanol 0.1%). At 6, 24, 48, hours, tissues supernatants were collected and assayed by ELISA for MIF. Tissues were frozen for assaying MIF expression by western blot analysis and real time PCR. Results: while physiological levels of E2 stimulated MIF release by chorionic villous explans, at higher concentration E2 significantly reduced MIF release in a time dependent manner. No changes were observed in tissues protein and mRNA content. Conclusion: given the crucial role of MIF as potent immunomodulator these findings suggest that Estrogens could play an important role in regulating the levels of released -MIF by the placental site

Pregnancy-promoting actions of HCG in human myometrium and fetal membranes

Human chorionic gonadotropin (HCG) plays a major role in early human development through a series of well recognized pregnancy-promoting actions that are exerted in the first trimester, including maternal recognition of pregnancy, enhancement of embryo implantation and survival, stimulation of trophoblast growth and differentiation, and prolongation of the functional life of the corpus luteum. Recent research indicates that HCG can exert significant pregnancy-promoting actions also in the remainder of pregnancy through its effect on the myometrium and on fetal membranes. In the myometrium, HCG promotes the inhibition of smooth muscle cell contractility through several mechanisms, including inhibition of gap junction formation, reduction of intracellular calcium concentration, increase in the expression of progesterone receptor, and an increase in the expression of phosphodiesterase 5 (PDE5), an enzyme controlling the intracellular levels of cGMP. This effect appears to be specific for PDE5 since it has not been found for other hormones potentially involved in pregnancy such as estrogen, progesterone and thyroid hormone. In fetal membranes, HCG can modulate expression of the inducible isoform of nitric oxide synthase (iNOS), as well as specific immunoregulatory cytokines such as the high mobility group box 1 (HMGB1) protein. This accumulating evidence suggests that HCG has a wide spread pregnancy-promoting actions that are exerted in various reproductive and gestational tissues

The Hemopoietic progenitor 32DCl3 (G) cells synthesize C3 molecules upon differentiation or neoplastic transformation

32DCl3(G) cells are a diploid, nontumorigenic, IL-3-dependent hemopoietic progenitor cell line, which undergoes terminal differentiation into neutrophilic granulocytes when cultured in presence of G-CSF. The infection with BALB-Moloney murine sarcoma virus, containing a v-HA-ras oncogene, renders this cell line IL-3 independent and continuously growing in the presence of G-CSF, nontumorigenic and with an apparent block at the level of promyelocyte/myelocyte (32D-Ha-ras). After infection with Abelson murine leukemia virus containing a v-abl oncogene, the cell line originates (32D-abl) that is also IL-3 independent but is tumorigenic and unable to differentiate in the presence of G-CSF. This cellular model allowed us to study the relationship between distinct steps of cell differentiation, neoplastic transformation, and C3 synthesis, activation, and characteristics of binding. We demonstrated that C3 synthesis, release, and cleavage are properties already present in the progenitor 32DCl3(G) cells. The more differentiated 32D-Ha-ras cells acquired C3 acceptor sites, apparently completely saturated by the constitutively released molecules. The transformation with Abelson murine leukemia virus, although it did not affect all these properties, let the cells bind considerable amounts of C3-related fragments activated in normal murine serum through the alternative pathway. This last event was a result of the acquisition of PMSF-sensitive serine proteases associated with the plasma membrane

Estradiol 17-beta and progesterone modulate inducible nitric oxide synthase and High Mobility Group Box 1 expression in human endometrium

The aim of the present study is to investigate the effects of ovarian sex steroid hormones on. the expression and the release of several locally active substances by human endometrium. Specific objectives are (1) to ascertain if estradiol 17-beta (E2) and progesterone modulate inducible nitric oxide synthase (iNOS) expression and nitric oxide release; (2) to determine whether human endometrium can express High Mobility Group Box 1 (HMGB1), a multifunctional cytokine, anal whether sexual steroid hormones can modulate this expression; and (3) to evaluate whether nitric oxide can influence HMGB1 expression in this tissue. Endometrial tissue was obtained front 40 healthy premenopausal women who underwent hysteroscopy for suspected benign gynecological conditions. Endometrium was incubated with E2, progesterone, or sodium nitroprusside, a nitric oxide donor. Nitrite assay was used to quantify stable nitric oxide metabolites in culture medium, and Western blot analysis was used to detect iNOS and HMGB1. Incubation of endometrium with E2 results in an increase in iNOS expression and nitric oxide metabolite production. The opposite effect is obtained by incubating tissues with progesterone. HMGB1 is expressed by human endometrium, and its expression is increased by E2 and decreased by progesterone. Incubation with sodium nitroprusside results in a reduction in HMGB1 expression. Bout E2 and progesterone modulate iNOS expression and nitric oxide production in human endometrium. HMGB1 is expressed in the human. endometrium, and its expression is modulated by E2, progesterone, and nitric oxide

Oxytocin induces HMGB1 expression and Nf-Kb activation in human fetal membranes at term gestation

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