[IL-6 up-regulates indoleamine 2, 3-dioxygenase (IDO) expression in chorionic villi and decidua].

Objective To investigate the regulatory effect of interleukin-6 (IL-6) on the expression of indoleamine 2, 3-dioxygenase (IDO) in the early pregnant chorionic villi and decidua tissues. Methods The chorionic villi and decidua tissues of women who received induced abortion at early pregnancy were collected. The expression of IL-6 and IDO in the chorionic villi and decidua tissues was detected by Western blotting. Subsequently, 10, 50 and 100 ng/mL IL-6 was added into the chorionic villi and decidua tissues to culture for 48 hours. In addition, changes in the IDO mRNA and protein expression levels in chorionic villi and decidua tissues were detected by real-time quantitative reverse PCR (qRT-PCR) and Western blotting. Results Both IDO and IL-6 were expressed in human early pregnant chorionic villi and decidua tissues. Besides, the expression of these two proteins were positively correlated (r=0.72, 0.91). After being cultured with 10, 50 and 100 ng/mL IL-6 for 48 hours, IDO protein expression significantly increased in the cultured early pregnant chorionic villi and decidua tissues in an IL-6 concentration-dependent manner. Conclusion The expression of IL-6 and IDO proteins at the maternal-fetal interface show a positive correlation in normal physiological pregnancy, and IL-6 may up-regulate the expression of IDO.

Estrogen induces IDO expression via TGF­ß in chorionic villi and decidua during early stages of pregnancy.

Indoleamine 2,3­dioxygenase (IDO) is one of the most important proteins protecting the embryos from the mother's immune system during pregnancy; however, little is known about the regulation of expression of this protein at the maternal­fetal interface. In the current study, chorionic villi and decidua were collected from women at early stages of pregnancy. Samples of chorionic villi and decidua were cultured in medium containing different concentrations of 17ß­estradiol and estriol respectively, with or without fulvestrant. Western blot analysis and/or immunofluorescent staining were used to detect the expression of transforming growth factor ß (TGF­ß) and IDO in chorionic villi and decidua tissues. Both TGF­ß and IDO were expressed in chorionic villi and decidua. The expression levels of these two proteins increased the most in samples of chorionic villi and decidua cultured in medium containing 17ß­estradiol at the concentration of 10 ng/ml, or estriol at the concentration of 1 µg/ml. This increase could be reversed when fulvestrant was added in the medium at the concentration of 10 µg/ml. IDO expression increased in a dose­dependent manner in tissue samples cultured in medium containing TGF­ß. The results of the current study revealed that administration of estrogen at doses similar to those observed in healthy pregnant women may upregulate the expression of IDO by TGF­ß, suggesting that estrogen may prevent allogeneic fetal rejection and may be used as an immunomodulator.

Estrogen induces indoleamine 2,3-dioxygenase expression via suppressors of cytokine signaling 3 in the chorionic villi and decidua of women in early pregnancy.

PROBLEM: Indoleamine 2,3-dioxygenase (IDO) is a key protein that participates in the protection of embryos against the mother's immune system during pregnancy. How the expression of this protein is regulated at the maternal-fetal interface remains largely unknown. METHOD OF STUDY: The chorionic villi and decidua of women in early pregnancy were collected. Tissue explants of the chorionic villi and decidua were cultured in media containing varying concentrations of 17ß-estradiol and estriol with or without fulvestrant. Western blot analysis and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the expression of IDO and the suppressors of cytokine signaling 3 (SOCS3) in the cultured tissues from chorionic villi and decidua. RESULTS: Both IDO and SOCS3 were expressed in chorionic villi and decidua. The expression of IDO was increased in tissue explants from chorionic villi and decidua cultured in medium containing different concentrations of 17ß-estradiol or estriol, and this increase was reversed when fulvestrant was added to the medium. The expression of IDO was upregulated, and SOCS3 expression was downregulated the most in tissue explants from chorionic villi and decidua that were cultured in medium containing 17ß-estradiol at a concentration of 10 ng/mL or estriol at a concentration of 1 µg/mL. This increase in IDO and decrease in SOCS3 were reversed when fulvestrant was added to the medium at a concentration of 10 µg/mL. CONCLUSION: At a concentration similar to that present during pregnancy, estrogen may upregulate the expression of IDO via downregulating SOCS3, which implies that estrogen may contribute to the prevention of allogeneic fetal rejection, and further studies may strengthen the possibility of using estrogen as an immune modulator.