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, and 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 from 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. Both 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

Pregnancy promoting action of HCG in huuman 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

17{beta}-Estradiol modulates the macrophage migration inhibitory factor secretory pathway by regulating ABCA1 expression in human first-trimester placenta.

Successful pregnancy involves a series of events, most of them mediated by hormones and cytokines. Estrogens, besides being important for placental growth and embryo development, have a marked effect on the immune system exerting either pro- or anti-inflammatory properties. Numerous studies suggest that estrogens directly affect cellular function, including cytokine production. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in pregnancy, particularly during the earlier stages of placentation. Since reports on mice have shown that estrogens modulate MIF, herein we investigated the effect of estrogens on human placental MIF. By using an in vitro model of first-trimester chorionic villous explants, we found that 17beta-estradiol (E(2)) was able to modulate the release of MIF in a dose-dependent manner (10(-12) vs. 10(-9) M, P 0.05; 10(-9) vs. 10(-5) M, P 0.05; 10(-12) vs. 10(-5) M, P 0.001). Unlike MIF release, no significant change in tissue MIF protein or MIF mRNA was observed. We showed evidence that E(2) concentrations (10(-9) and 10(-5) M) act on placental tissue downregulating the mRNA and protein expression of the ATP-binding cassette transporter protein A1, a membrane transporter involved in MIF secretion. These findings emphasize the mutual cooperation between hormones and cytokines and suggest that increasing estrogen levels with advancing gestation may have a major role in regulating placental MIF secretion

Oxytocin modulates nitric oxide generation by human fetal membranes at term pregnancy

PROBLEM: Nitric oxide (NO), an important mediator of the inflammatory response, is involved in several reproductive processes including pregnancy and labor. Uterus, placenta and fetal membranes are significant sources of NO. Presently, there is no information on factors regulating NO production by fetal membranes. METHOD OF STUDY: Human fetal membranes at term gestation were cultured for 24 hr in the presence of oxytocin. The concentrations of NO metabolites nitrites in culture medium were determined by the Griess reaction. The presence of inducible nitric oxide synthase (iNOS) was determined by reverse transcriptase-polymerase chain reaction and Western blot. RESULTS: Oxytocin increased nitrite release by fetal membranes. Messenger ribonucleic acid iNOS expression was also enhanced by oxytocin. These effects were more marked in tissues obtained after labor than before labor. CONCLUSIONS: Oxytocin exerts an overall stimulatory effect on NO release by fetal membranes. This action might be of relevance in the biomolecular processes leading to parturition

Hormonal regulation of cytokine release by human fetal membranes at term gestation: effects of oxytocin,hydrocortisone and progesterone on TNFa and TGFbeta out put -

Inflammatory cytokines can play an important role in the biomolecular processes leading to labour by regulating prostaglandin production in intrauterine tissues. In the setting of intrauterine infection, an increased production of these cytokines by placenta, decidua and fetal membranes occurs and is responsible for the onset and maintenance of preterm labour. However, the factors involved in the control of cytokine release by these tissues in normal pregnancy at term are still largely unknown. We investigated the possibility that the synthesis and release of tumour necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta1 (TGF-beta1) by human fetal membranes at term gestation is regulated by several hormones potentially involved either in the maintenance of pregnancy or in the parturitional process. In the present study, the effects of hydrocortisone, progesterone and oxytocin on TNF-alpha and TGF-beta1 release by explants of fetal membranes at term gestation were evaluated. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the effect of the above hormones on mRNA expression; TNF-alpha and TGF-beta1 release in culture medium was quantitifed by ELISA assays. Results show that both tissue mRNA expression for TNF-alpha and TNF-alpha release in culture medium were significantly increased by oxytocin, but not by hydrocortisone and progesterone. On the contrary, all the hormones tested increased both tissue TGF-beta1 mRNA expression and release in culture medium. These findings suggest that TNF-alpha and TGF-beta1 production by human fetal membranes in uncomplicated pregnancy at term is selectively modulated by oxytocin, hydrocortisone and progesterone