T follicular helper 17 (Tfh17) cells are superior for immunological memory maintenance

A defining feature of successful vaccination is the ability to induce long-lived antigen-specific memory cells. T follicular helper (Tfh) cells specialize in providing help to B cells in mounting protective humoral immunity in infection and after vaccination. Memory Tfh cells that retain the CXCR5 expression can confer protection through enhancing humoral response upon antigen re-exposure but how they are maintained is poorly understood. CXCR5⁺ memory Tfh cells in human blood are divided into Tfh1, Tfh2, and Tfh17 cells by the expression of chemokine receptors CXCR3 and CCR6 associated with Th1 and Th17, respectively. Here, we developed a new method to induce Tfh1, Tfh2, and Tfh17-like (iTfh1, iTfh2, and iTfh17) mouse cells in vitro. Although all three iTfh subsets efficiently support antibody responses in recipient mice with immediate immunization, iTfh17 cells are superior to iTfh1 and iTfh2 cells in supporting antibody response to a later immunization after extended resting in vivo to mimic memory maintenance. Notably, the counterpart human Tfh17 cells are selectively enriched in CCR7⁺ central memory Tfh cells with survival and proliferative advantages. Furthermore, the analysis of multiple human cohorts that received different vaccines for HBV, influenza virus, tetanus toxin or measles revealed that vaccine-specific Tfh17 cells outcompete Tfh1 or Tfh2 cells for the persistence in memory phase. Therefore, the complementary mouse and human results showing the advantage of Tfh17 cells in maintenance and memory function supports the notion that Tfh17-induced immunization might be preferable in vaccine development to confer long-term protection.

RhoB Promotes Endometrial Stromal Cells Decidualization Via Semaphorin3A/PlexinA4 Signaling in Early Pregnancy

Endometrial decidualization refers to a series of morphological changes and functional remodeling of the uterine endometrium to accept the embryo under the effect of estrogen and progesterone secreted by ovaries after ovulation. During decidualization, endometrial stromal cells (ESCs) proliferate and differentiate into decidual stromal cells, undergoing cytoskeletal rearrangement-mediated morphological changes and expressing decidualization markers, such as insulin-like growth factor-binding protein-1 and prolactin. Ras homology (Rho) proteins, a family of small G proteins, are well known as regulators of cellular morphology and involved in multiple other cellular processes. In this study, we found ras homolog family member B (RHOB) was the most significantly upregulated gene in the Rho protein family after the in vitro decidualization of human primary ESCs. RhoB expression was induced mainly by 3',5'-cyclic adenosine 5'-monophosphate (cAMP) / protein kinase A (PKA) / cyclic adenosine monophosphate-response element binding protein signaling and partly by progesterone signaling. Knockdown of RhoB in ESCs greatly inhibited actin cytoskeletal rearrangement, cell morphological transformation, and upregulation of insulin-like growth factor-binding protein-1, suggesting an indispensable role of RhoB in decidualization. Mechanistically, the downstream target of RhoB was semaphorin3A (Sema3A), which mediated its signaling via interacting with the receptor, plexinA4. More importantly, decreased expression of RhoB, Sema3A, and plexinA4 were detected in deciduas from patients with unexplained spontaneous miscarriage. Collectively, our results indicate that RhoB/Sema3A/plexinA4 signaling plays a positive role in endometrial decidualization and relates to unexplained spontaneous miscarriage, which is worthy of further exploration so as to provide new insights into therapeutic strategies for pregnancy diseases associated with poor decidualization.

MicroRNA let-7i inhibits granulosa-luteal cell proliferation and oestradiol biosynthesis by directly targeting IMP2

RESEARCH QUESTION

Increased granulosa cell division is associated with abnormal folliculogenesis in polycystic ovary syndrome (PCOS). Lethal-7i microRNA (let-7i) may play an important role in the follicular development and granulosa cell growth; therefore is let-7i involved in PCOS pathogenesis?

DESIGN

The expression of let-7i was measured in granulosa-luteal cells (GLC) from women with or without PCOS. A human granulosa cell line, KGN, was used for the functional study. Mimics and inhibitors of let-7i, lentiviruses expressing insulin-like growth factor 2 mRNA binding protein (IMP2), and small-interfering RNAs were transfected into KGN cells. KGN cell proliferation was determined by 5-ethynyl-2'-deoxyuridine (EdU) and Cell Counting Kit-8 (CCK-8) assays. The cell cycle and apoptosis were assessed by propidium iodide-annexin V (PI-A) staining and fluorescence-activated cell sorting. Oestradiol concentration was determined by enzyme-linked immunoassay. Bioinformatics analysis and luciferase reporter assay were applied to confirm the let-7i target genes.

RESULTS

The study showed that let-7i was down-regulated in PCOS GLC (P = 0.001). Mimics of let-7i inhibited KGN proliferation (P = 0.001), and decreased aromatase expression (P = 0.030) and oestradiol production (P = 0.029), whereas let-7i inhibitors had the opposite effect. Bioinformatics analysis and quantitative real-time (qRT) PCR identified IMP2 as a target of let-7i (P = 0.021). qRT-PCR and western blot analysis indicated that IMP2 was up-regulated in GLC in women with PCOS (P = 0.001 and P = 0.044), and IMP2 expression was suppressed by let-7i in KGN cells (P < 0.001). Luciferase reporter assay results (P = 0.002), combined with the rescue assay, confirmed that let-7i inhibited KGN cell proliferation and reduced oestradiol concentration by directly targeting IMP2.

CONCLUSIONS

let-7i was down-regulated in PCOS GLC. Overexpression of let-7i inhibited KGN cell proliferation and decreased oestradiol production in an IMP2-dependent manner, providing a new molecular mechanism for PCOS.

The risk of intrauterine exposure to SARS-CoV-2 in female COVID-19 patients: A comprehensive review

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is a new type of coronavirus that has caused fatal infectious diseases and global spread. This novel coronavirus attacks target cells through the interaction of spike protein and angiotensin‐converting enzyme II (ACE2), leading to different clinical symptoms. However, for a successful pregnancy, a well‐established in‐uterine environment includes a specific immune environment, and multi‐interactions between specific cell types are prerequisites. The immune‐related changes in patients infected with novel coronavirus could interfere with the immune microenvironment in the uterus, leading to fetal loss. We first reviewed the intrauterine environment in the normal development process and the possible pregnancy outcome in the infection state. Then, we summarized the immune response induced by SARS‐CoV‐2 in patients and analyzed the changes in ACE2 expression in the female reproductive system. Finally, the present observational evidence of infection in pregnant women was also reviewed.

Wnt16 from decidual stromal cells regulates HTR8/SVneo trophoblastic cell function via Akt/β-catenin pathway

Decidual stromal cells (DSCs) modulate the function of trophoblasts through various factors. Wnt signaling pathway is active at the maternal-fetal interface. Here we isolated Endometrial stromal cells (ESCs), from women of reproductive ages, and DSCs, from normal pregnancy during the first trimester (6-10 weeks). qRT-PCR and western blotting were used to screen out the most variable Wnt ligands between ESCs and DSCs, which turned out to be Wnt16. Both culture medium from DSCs and recombinant protein of human Wnt16 enhanced the survival and invasion of HTR8/SVneo trophoblastic cells. Furthermore, the regulation of DSCs on trophoblast was partly blockaded after we knocked down Wnt16 in DSCs. Treating HTR8/SVneo with small molecular inhibitors and small interfering RNA, we found that the activity of Akt/β-catenin correlated with the effect of Wnt16. The crosstalk of Wnt16/Akt/β-catenin between DSCs and trophoblasts was determined to be downregulated in unexplained recurrent spontaneous abortion. This study suggests that Wnt16 from DSCs promotes HTR8/SVneo trophoblastic cells invasion and survival via Akt/β-catenin pathway at the maternal-fetal interface in human early pregnancy. The disturbance of this crosstalk between DSCs and trophoblasts might cause pregnancy failure.

Evaluation of inactivated COVID-19 vaccine on semen parameters in reproductive-age males: a retrospective cohort study

During the coronavirus disease (COVID-19) epidemic, there have been concerns about the impact of vaccines on people's fertility, including the fertility of those who are currently preparing for pregnancy and those who might become pregnant in future. However, there is still a lack of research on the effect of the COVID-19 vaccine on male fertility, and it is not surprising that couples and donors have concerns regarding vaccination. In this study, a retrospective cohort study was conducted to examine semen quality before and after receipt of the inactivated COVID-19 vaccine. There were no statistically significant changes in semen parameters (volume, sperm concentration, progressive motility, and total progressive motile count) after two doses of vaccine (all P > 0.05). In summary, our study updates the most recent studies on the effects of the COVID-19 vaccine on male fertility, and the information from this study could be used to guide fertility recommendations for assisted reproductive technology (ART) patients and donors.

SCM-198 Prevents Endometriosis by Reversing Low Autophagy of Endometrial Stromal Cell via Balancing ERα and PR Signals

BACKGROUND

Endometriosis (EMS), an endocrine-related inflammatory disease, is characterized by estrogen and progesterone imbalance in ectopic lesions. However, its pathogenic mechanism has not been fully elucidated. While SCM-198 is the synthetic form of leonurine and has multiple pharmacological activities such as antioxidation and anti-inflammation, it remains unknown whether it could inhibit the progress of EMS by regulating estrogen signaling and inflammation.

METHODS

The therapeutic effects of SCM-198 on EMS and its potential mechanism were analyzed by establishing EMS mouse models and performing an RNA sequencing (RNA-seq) assay. ELISA was performed to detect estrogen and tumor necrosis factor (TNF) -α concentrations in normal endometrial stromal cells (nESCs) and ectopic endometrial stromal cells (eESCs) with or without SCM-198 treatment. Western blotting, RNA silencing, and plasmid overexpression were used to analyze the relationship between inflammation, endocrine factors, and autophagy and the regulatory activity of SCM-198 on the inflammation-endocrine-autophagy axis.

RESULTS

Increased estrogen-estrogen receptor (ER) α signaling and decreased progesterone receptor isoform B (PRB) expression synergistically led to a hypo-autophagy state in eESCs, which further inhibited the apoptosis of eESCs. The high expression of TNF-α in eESCs enhanced the antiapoptotic effect mediated by low autophagy through the activation of the aromatase-estrogen-ERα signaling pathway. SCM-198 inhibited the growth of ectopic lesions in EMS mice and promoted the apoptosis of eESCs both in vivo and in vitro. The apoptotic effect of SCM-198 on eESCs was attained by upregulating the autophagy level via the inhibition of the TNF-α-activated aromatase-estrogen-ERα signal and the increase in PRB expression.

CONCLUSION

Inflammation facilitated the progress of EMS by disrupting the estrogen regulatory axis. SCM-198 inhibited EMS progression by regulating the inflammation-endocrine-autophagy axis.

Asymmetric dimethylarginine contributes to retinal neovascularization of diabetic retinopathy through EphrinB2 pathway

Diabetic retinopathy (DR) is a leading cause of vision loss with retinal neovascularization. This study aims to investigate whether Asymmetric dimethylarginine (ADMA) impacts the pathogenesis of DR via focusing on promoting retinal neovascularization and its underlying molecular mechanisms. Diabetic rats were induced by a single intraperitoneal injection of streptozotocin (STZ) for 20 weeks. ADMA levels in aqueous and the influence of hypoxia on ADMA and angiogenesis in RF/6A cells were examined. The effects and underlying molecular mechanisms of ADMA on neovascularization of RF/6A cells were further evaluated by administration of ADMA, DDAH siRNA or ephrinB2 siRNA. Results showed that ADMA levels were elevated in both aqueous from diabetic rats and culture medium in RF/6A cells pretreated with hypoxia. Administration of ADMA directly promoted proliferation, migration, adhesion and tube formation of RF/6A cells, which was further confirmed by DDAH1 siRNA or DDAH2 siRNA. In addition, ephrinB2 expression was increased under diabetic conditions, and the angiogenic effects of ADMA were blocked by ephrinB2 siRNA. In conclusion, ADMA contributes to the neovascularization of retina in diabetic mellitus, which is regulated by ephrinB2.

Relationship between receipt of substitutable for-fee vaccines and completion of the expanded programme on immunisation: a cross-sectional study in Fujian, China

OBJECTIVE

The aim of this study was to evaluate the relationship between receipt of the substitutable-for-fee vaccines (SFV) and completion of the expanded programme on immunisation (EPI).

DESIGN AND SETTINGS

A cross-sectional study was conducted in Fujian province, China.

PARTICIPANTS

Children who were born from 1 September 2009 to 31 August 2011, and who had been residing in the township for at least 3 months, were randomly recruited from 34 townships.

MAIN OUTCOMES MEASURES

Outcomes were completion rate of the EPI and coverage rate of the SFV.

RESULTS

The study included 1428 children, of whom 1350 (94.5%) finished the EPI and 282 (19.7%) received at least one dose of the SFV. Administration of the SFV was associated with an increased likelihood of completing the EPI (OR=3.2, 95% CI 1.3 to 7.6 in the total sample and OR=4.0, 95% CI 1.7 to 9.6 in the subsample of children in regions with the SFV accessibility). The impact of the SFV administration on completion of the EPI was larger among children whose parents have junior school education or less (97.8% and 97.9% vs 92.5% and 91.9%, both p<0.001) and among those with a timely hepatitis B vaccine first dose (98.5% vs 94.0%, p<0.001).

CONCLUSIONS

Receipt of SFV is associated with increased likelihood of completion of the EPI in Fujian, China.

dNK cells facilitate the interaction between trophoblastic and endothelial cells via VEGF-C and HGF

Decidual NK (dNK) cells, identified as CD56^brightCD16^-CD3^-, account for ~70% of lymphocytes within the uterine wall during early pregnancy. Accumulating evidence suggests that tight interactions between placental trophoblasts and dNK cells are critical for trophoblast cell differentiation. However, the underlying mechanism remains to be explored in detail. In the present study, conditioned medium (CM) was collected from cultured primary human dNK cells. Primary cytotrophoblasts (CTBs) or the human trophoblast cell line HTR8/SVneo was treated with dNK-CM and co-cultured with human umbilical vein endothelial cells (HUVECs) in a three-dimensional Matrigel scaffold, and the formation of tube structures was dynamically monitored with live cell imaging. Trophoblast invasion was analyzed with a transwell invasion assay. The data demonstrated that the treatment of HTR8/SVneo cells or CTBs with dNK-CM remarkably promoted trophoblast invasion and tube formation in the presence of HUVECs. The epithelial marker E-cadherin was reduced, while the expression of endothelial markers NCAM, VE-cadherin and integrin β1 was significantly promoted in the HTR8/SVneo cells upon treatment with dNK-CM. Antibody blocking experiments revealed that the dNK cells promoted trophoblast invasion through the production of IL-8 and HGF, and they induced trophoblast differentiation toward endothelial phenotype by producing VEGF-C and HGF. These results provide new evidence to clarify the finely tuned interactions between trophoblasts and dNK cells at the maternal-fetal interface.

Inhibition of AKT sensitizes chemoresistant ovarian cancer cells to cisplatin by abrogating S and G2/M arrest

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is frequently altered in human malignancies and Akt over-expression and/or activation induces malignant transformation and chemoresistance. However, the role of Akt in the mechanisms of chemoresistance remains elusive. Here we reported that cisplatin treatment of chemosensitive, but not resistant, ovarian cancer cells (OVCAs) markedly increased the cell proportion in sub-G1 phase. Cisplatin however caused a significant accumulation of the resistant cells in S and G2/M phases, which was associated with a rapid and sustained checkpoint kinase 1 (Chk1) activation. In contrast, while cisplatin also elicited a rapid activation of Chk1 in sensitive cells, it markedly decreased total ChK1 and phospho-Chk1 contents over 12 h. Over-expression of dominant negative (DN)-AKT alone increased phospho-Chk1 content, and induced G2/M arrest and apoptosis. However, it inhibited Chk1 activation and G2/M arrest with combination of cisplatin treatment, resulting in p53-independent apoptosis. Furthermore, the responses of the chemoresistant cells to cisplatin were attenuated with forced expression of constitutive active AKT2. Chk1 knock-down also facilitated cisplatin-induced apoptosis in chemoresistant cells. Our studies implicate that, in addition to its cell survival and anti-apoptotic actions, Akt might also play an important role in the regulation of G2-M transition, possibly via up-regulation of Chk1 activity and stability. These data provide strong support for the concept that Akt is important in cell cycle regulation in the control of chemosensitivity in OVCAs and offers an alternate regulatory pathway for the development of rationale therapy for cisplatin-resistant ovarian cancer.

Combination of CD4(+)CD25(+)CD127(-) regulatory T cells with MLC-BE and BE-Ab2: an efficient evaluation of the therapy of paternal lymphocyte induced immunization in unexplained recurrent spontaneous abortion patients

The aim of this retrospective study was to compare the immune tolerance status of patients suffered from unexplained spontaneous abortion (URSA) before and after treatment with paternal lymphocyte induced immunization (PLII) four times, and its relationship to the pregnancy outcome. 168 URSA patients were included in the present study. Among 168 couples, 138 couples were conceived again, of whom 86 were successfully pregnant till 20 gestational weeks, 31 cases again failed in the first trimester, 21 cases were still under follow-up, another 30 cases still had not conceived. Both the level of one way mixed lymphocyte culture blocking efficiency (MLC-BE) and anti-idio blocking antibody (BE-Ab2) were markedly elevated in succeeded group after PLII. In contrast, although a significant increase could be observed in the failed group after treatment, the elevation of BE-Ab2 was much lower than that in successful group. PLII therapy significantly up-regulated the percentage of peripheral CD4(+)CD25(+)CD127(-) regulatory T cells (Tregs) in successfully pregnant women; however, there was no significant change of Tregs in pregnancy loss cases although receiving PLII therapy. These results suggested a positive correlation between higher frequency of Tregs and rate of successful pregnancies. The sensitivity and specificity of combination of Tregs with MLC-BE and BE-Ab2 were 81.8% and 81.3%, respectively. Therefore, the percentage of Tregs in peripheral blood may hopefully serve as a potential biomarker for monitoring the efficacy of therapy in URSA patients. Combination of Tregs with MLC-BE and BE-Ab2 may expect to better evaluate the efficacy of PLII in URSA patients.

Co-expression of CXCR4 and CXCR7 in human endometrial stromal cells is modulated by steroid hormones

Endometrium modulated by estrogen (E) and progesterone (P) is important for implantation and pregnancy. The present study compared the expression of chemokine CXCL12 and chemokine receptor CXCR4 and CXCR7 between human cycling and early pregnant endometria by immunohistochemistry (IHC). Then the modulation of E and P on expression of CXCL12, CXCR4 and CXCR7 in human endometrial stromal cells (ESCs) was explored at both mRNA and protein level. The result of IHC showed that human ESCs of the menstrual period did not express CXCL12, CXCR4 or CXCR7 protein, however, the expression of CXCR4 and CXCR7 but not CXCL12 in ESCs increased in the proliferative and secretory phase, and the expression intensity for CXCR4 and CXCR7 in ESCs was the highest in the first trimester. Moreover, E and P were able to up-regulate the mRNA and protein expression of CXCR4 and protein expression of CXCR7 in ESCs (P<0.01). Thus, ESCs spatiotemporally co-express CXCR4 and CXCR7 rather than CXCL12, and E and P are able to regulate the expression of CXCR4 and CXCR7 in ESCs, suggesting the modulation of steroid hormones on chemokine receptor expression in ESCs.

The integrative roles of chemokines at the maternal-fetal interface in early pregnancy

Embryos express paternal antigens that are foreign to the mother, but the mother provides a special immune milieu at the fetal-maternal interface to permit rather than reject the embryo growth in the uterus until parturition by establishing precise crosstalk between the mother and the fetus. There are unanswered questions in the maintenance of pregnancy, including the poorly understood phenomenon of maternal tolerance to the allogeneic conceptus, and the remarkable biological roles of placental trophoblasts that invade the uterine wall. Chemokines are multifunctional molecules initially described as having a role in leukocyte trafficking and later found to participate in developmental processes such as differentiation and directed migration. It is increasingly evident that the gestational uterine microenvironment is characterized, at least in part, by the differential expression and secretion of chemokines that induce selective trafficking of leukocyte subsets to the maternal-fetal interface and regulate multiple events that are closely associated with normal pregnancy. Here, we review the expression and function of chemokines and their receptors at the maternal-fetal interface, with a special focus on chemokine as a key component in trophoblast invasiveness and placental angiogenesis, recruitment and instruction of immune cells so as to form a fetus-supporting milieu during pregnancy. The chemokine network is also involved in pregnancy complications.

CD56(bright)CD25+ NK cells are preferentially recruited to the maternal/fetal interface in early human pregnancy

Decidual natural killer (dNK) cells are believed to be critical for maintaining maternal/fetal tolerance and regulating placental vascular remodeling based upon their abundance and unique phenotype during early pregnancy. However, the mechanism for how the dNK cells play such important roles in successful pregnancy remains undefined. Here, we identified a subtype of dNK cells characterized as having a CD3(-)CD56(bright)CD25(+) phenotype. We found that CD56(bright)CD25(+) NK cells preferentially localize to the maternal/fetal interface during early human pregnancy. CD25(+) dNK cells account for approximately 75% of CD25-expressing decidual immune cells (DICs). However, less than 5% of CD25-positive peripheral blood mononuclear cells are CD25(+) NK cells. Furthermore, CD25(+) and CD25(-) dNK cells exhibit distinct phenotypes: CD25(+) dNK cells display a more activated phenotype and greater cytokine-secreting capacity. Interestingly, coculture of peripheral NK (pNK) cells with primary trophoblasts upregulates the percentage of CD25-expressing pNK cells, resulting in increased expression of activation markers and cytokine production by pNK cells. In addition, we demonstrated that the CXCL12/CXCR4 axis is crucial for the recruitment of CD25(+) dNK cells and contributes to the accumulation of CD3(-)CD56(bright)CD25(+) dNK cells at the maternal/fetal interface. Thus, our data reveal that the crosstalk between trophoblasts and pNK cells leads to the accumulation of CD3(-)CD56(bright)CD25(+) dNK cells, which exert a regulating effect at the maternal/fetal interface.

Cyclosporine A improves adhesion and invasion of mouse preimplantation embryos via upregulating integrin β3 and matrix metalloproteinase-9

Our previous study has demonstrated cyclosporin A (CsA) promotes the migration and invasiveness of human first-trimester trophoblast cells in vitro. Here, we further investigated the effect of CsA on the early implantation in vitro of mouse embryo. Female C57 mice were superovulated and mated, and then two-cell embryos were harvested from the oviducts and sequentially cultured in vitro in G1 and G2 media with 0, 0.1, 1.0 or 10 μM of CsA. Blastocyte formation, blastocyte cell number and apoptosis, embryo hatching were assessed in 4-6 dpc. The adhesion and stretching growth of hatched embryos in laminin coated dishes were evaluated from 5 dpc to 8 dpc, and the expressions of implantation serine proteinase 1 (ISP1), integrin (itg) β3 and matrix metalloproteinase (MMP)-9 were determined by real time PCR and immunofluorescence, respectively. We showed there was no significant difference in blastocyst formation rates, hatching rates, number of whole embryonic cells, apoptotic cells, and distribution of inner cell masses (ICMs) and trophoblasts (TB) between the CsA- and control-treated groups. Expression of ISP1 mRNA was unaffected on 5 dpc. After hatching, adhesion rate of 7 dpc significantly increased in 0.1 and 1.0 μM of CsA treatment, and embryo area of 8 dpc stretch growing on laminin were increased in 1.0 μM of CsA. The mRNA and protein expression of itgβ3 and MMP-9 on 7 dpc blastocyst were up-regulated. In conclusion, CsA in low dosage up-regulates itgβ3 and MMP-9 expression, and enhances embryonic adhesion and invasion, which is beneficial to the embryo implantation.

Trophoblasts and decidual stromal cells regulate decidual NK cell functions via interaction between collagen and LAIR-1

PROBLEM

To determine the effect of collagen from maternal-fetal interface on decidual natural killer cell (dNK) function.

METHOD OF STUDY

Decidual and villous samples were collected from normal pregnancy and miscarriage. The phenotype and cytokine production were analyzed, respectively, by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Co-culture was established to investigate the effect of trophoblasts and decidual stromal cells (DSCs) on dNKs.

RESULTS

Maternal-fetal interface of normal pregnancy showed higher collagen and LAIR-1 expression than that of miscarriage. Co-culture of dNKs with HTR-8/DSCs up-regulated LAIR-1 on dNKs that could be attenuated by pre-treatment with LAIR-2, a competitive inhibitor of LAIR-1. Collagen down-regulated expression of cell surface receptor activity and intracellular perforin, while it up-regulated expression of suppressive receptor on dNKs. Co-culture of dNKs with HTR-8/DSCs decreased perforin expression and Th1-type cytokines production by dNKs, which could be abrogated by LAIR-2. In addition, silence of collagen in HTR-8/DSCs by shRNA significantly attenuated regulation on dNKs.

CONCLUSION

Trophoblasts and DSCs regulate decidual NK cell functions via secreting collagen, which is involved in the maintenance of human pregnancy.

Embryonic trophoblasts induce decidual regulatory T cell differentiation and maternal-fetal tolerance through thymic stromal lymphopoietin instructing dendritic cells

Physiological pregnancy requires the maternal immune system to recognize and tolerate embryonic Ags. Although multiple mechanisms have been proposed, it is not yet clear how the fetus evades the maternal immune system. In this article, we demonstrate that trophoblast-derived thymic stromal lymphopoietin (TSLP) instructs decidual CD11c(+) dendritic cells (dDCs)with increased costimulatory molecules; MHC class II; and Th2/3-type, but not Th1-type, cytokines. TSLP-activated dDCs induce proliferation and differentiation of decidual CD4(+)CD25(-) T cells into CD4(+)CD25(+)FOXP3(+) regulatory T cells (Tregs) through TGF-β1. TSLP-activated dDC-induced Tregs display immunosuppressive features and express Th2-type cytokines. In addition, decidual CD4(+)CD25(+)FOXP3(+) Tregs promote invasiveness and HLA-G expression of trophoblasts, resulting in preferential production of Th2 cytokines and reduced cytotoxicity in decidual CD56(bright)CD16(-) NK cells. Of interest, decreased TSLP expression and reduced numbers of Tregs were observed at the maternal-fetal interface during miscarriage. Our study identifies a novel feedback loop between embryo-derived trophoblasts and maternal decidual leukocytes, which induces a tolerogenic immune response to ensure a successful pregnancy.

Expression of anti-Müllerian hormone in letrozole rat model of polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age with anti-müllerian hormone (AMH) two to three times higher, but the mechanism of increased AMH, excessive follicles and follicle stagnation in PCOS still needs further research.

METHODS

Female Sprague-Dawley rats were treated with a gavage of 1.0 mg/kg of letrozole carboxymethylcellulose solution once daily for 21 consecutive days. Serum steroid concentrations, ovarian morphology, ovarian expression of AMH and AMH-RII protein were determined and their relationships were studied.

RESULTS

According to the morphology and endocrinology, the letrozole model group was a successful PCOS model. Serum AMH and ovarian local expression of AMH and AMH-RII were both increased in letrozole model group. The elevated AMH had a positive correlation with T, growing follicle count and a negative correlation with body weight.

CONCLUSIONS

The letrozole model group is a good animal model for the study of AMH in PCOS patients with obesity or insulin resistance. The increased serum AMH level in PCOS is the consequence of the androgen-induced excess of small antral follicles. These results lead to the hypothesis that reducing AMH may become a therapeutic target of PCOS, which is worth further research.

The 3rd international conference on reproductive immunology in Shanghai: September 27-29, 2013. Shanghai, China

PROBLEM

After the first and second international conferences on reproductive immunology held by Dr. DaJin Li in Shanghai, the related investigators all over the world hope to get together to share their latest findings with each other.

METHOD OF STUDY

Drs. DaJin Li and MeiRong Du sponsored and organized the third international conference on reproductive immunology at the Obstetrics and Gynecology Hospital affiliated with Fudan University, Shanghai, China, in the autumn of 2013.

RESULTS

This congress brought together more than 100 International and National investigators representing a wide range of scientific disciplines. All the investigators actively work on reproductive immunology using human or large and small animal models. A range of reproductive immunological topics including the maternal-fetal immune regulation, reproductive tract mucosal immunology, immunocontraception, and pregnancy complications were highlighted and discussed in this conference.

CONCLUSION

This conference supplied a good platform for the international reproductive immunologists to exchange their latest study progression and discuss the development direction of reproductive immunology in the near future.

Hyaluronan-CD44 interaction promotes growth of decidual stromal cells in human first-trimester pregnancy

Hyaluronan (HA) and its receptor CD44 are expressed at the maternal-fetal interface, but its role in early pregnancy remains unclear. Here, we found that primary decidual stromal cells (DSCs) continuously secreted HA and expressed its receptor CD44. Pregnancy-associated hormones up-regulated HA synthetase (HAS) 2 transcription and HA release from DSCs. High molecular weight-HA (HMW-HA), but not medium molecular weight (MMW-HA) or low molecular weight (LMW-HA), promoted proliferation and inhibited apoptosis of DSCs in a CD44-dependent manner. The in-cell Western analysis revealed HMW-HA activated PI3K/AKT and mitogen-activated protein kinase (MAPK)/ERK1/2 signaling pathways time-dependently. Blocking these pathways by specific inhibitor LY294002 or U0126 abrogated HMW-HA-regulated DSc proliferation and apoptosis. Finally, we have found that HA content, HA molecular weight, HAS2 mRNA level, and CD44 expression were significantly decreased in DSCs from unexplained miscarriage compared with the normal pregnancy. Collectively, our results indicate that higher level and greater molecular mass of HA at maternal-fetal interface contributes to DSc growth and maintenance of DSCs in human early pregnancy.

Cyclosporin A promotes proliferating cell nuclear antigen expression and migration of human cytotrophoblast cells via the mitgen-activated protein kinase-3/1-mediated nuclear factor-κB signaling pathways

Our previous studies have demonstrated that cyclosporin A (CsA) promotes the proliferation and migration of human trophoblasts via the mitgen-activated protein kinase-3/1 (MAPK3/1) pathway. In the present study, we further investigated the role of nuclear factor (NF)-κB in the CsA-induced trophoblast proliferating cell nuclear antigen (PCNA) expression and migration, and its relationship to MAPK3/1 signal. Flow cytometry was used to analyze the expression of PCNA in trophoblasts. The migration of human primary trophoblasts was determined by wound-healing assay and transwell migration assay. Western blot analysis was performed to evaluate the activation of NF-κB p65 and NF-κB inhibitory protein I-κB in human trophoblasts. We found that treatment with CsA promotes PCNA expression and migration of human trophoblast in a dose-associated manner. Blocking of the MAPK3/1 signal abrogated the enhanced PCNA expression and migration in trophoblasts by CsA. In addition, CsA increased the phosphorylation of NF-κB p65 and the inhibitor I-κB in human trophoblasts in a time-related manner. Pretreatment with MAPK3/1 inhibitor U0126 abrogated the phosphorylation of NF-κB p65 and I-κB. Accordingly, the CsA-induced enhancement of PCNA expression and migration in trophoblasts was also decreased. This CsA-induced enhancement in the expression and migration of trophoblasts was abolished by pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor. Thus, our results suggest that CsA promotes PCNA expression and migration of human trophoblasts via MAPK-mediated NF-κB activation.

Chemokine CCL28 induces apoptosis of decidual stromal cells via binding CCR3/CCR10 in human spontaneous abortion

Spontaneous abortion is the most common complication of pregnancy. Immune activation and the subsequent inflammation-induced tissue injury are often observed at the maternal-fetal interface as the final pathological assault in recurrent spontaneous abortion. However, the precise mechanisms responsible for spontaneous abortion involving inflammation are not fully understood. Chemokine CCL28 and its receptors CCR3 and CCR10 are important regulators in inflammatory process. Here, we examined the expression of CCL28 and its receptors in decidual stromal cells (DSCs) by immunochemistry and flow cytometry (FCM), and compared their expression level in DSCs from normal pregnancy versus spontaneous abortion, and their relationship to inflammatory cytokines production by DSCs. We further analyzed regulation of the pro-inflammatory cytokines on CCL28 expression in DSCs by real-time polymerase chain reaction, In-cell Western and FCM. The effects of CCL28-CCR3/CCR10 interaction on DSC apoptosis was investigated by Annexin V staining and FCM analysis or DAPI staining and nuclear morphology. Higher levels of the inflammatory cytokines interleukin (IL)-1β, IL-17A and tumor necrosis factor-α, and increased CCR3/CCR10 expression were observed in DSCs from spontaneous abortion compared with normal pregnancy. Treatment with inflammatory cytokines differently affected CCL28 and CCR3/CCR10 expression in DSCs. Human recombinant CCL28 promoted DSC apoptosis, which was eliminated by pretreatment with neutralizing antibodies against CCR3/CCR10 and CCL28. However, CCL28 did not affect DSC growth. These results suggest that the inflammation-promoted up-regulation of CCL28 and its receptors interaction in DSCs is involved in human spontaneous abortion via inducing DSC apoptosis.

Trophoblasts-derived chemokine CCL24 promotes the proliferation, growth and apoptosis of decidual stromal cells in human early pregnancy

Chemokine CCL24 is the second member of eotaxins, a group of eosinophils' selectively chemoattractants. Via binding to its only receptor CCR3, CCL24 mainly mediates atopic disorders, parasitic infections and systemic diseases. It is well-known that CCR3 is expressed at the maternal-fetal interface; nevertheless whether CCL24 is located there and which role CCL24/CCR3 axis played is unclear. In this article, we assessed the expression of CCL24 and CCR3 in decidual stromal cells (DSCs) and trophoblasts, investigated the effects of DSCs-trophoblasts contact and pregnancy-associated hormones on the expression of CCR3 by DSCs, and last examined the role of trophoblasts-derived CCL24 on the proliferation, cell numbers and apoptosis of DSCs in vitro. We found that trophoblasts secrete chemokine CCL24, whereas DSCs express receptor CCR3. DSCs and trophoblasts co-culture had an raised level of CCL24 in culture supernatants, and the expression of CCR3 on DSCs was also obviously improved. Estrogen, progesterone and hCG up-regulated the expression of CCR3 on DSCs at appropriate concentration. CCL24 increased the proliferation and apoptosis of DSCs, whereas on the whole it promoted the number of DSCs. Thus, we conclude that by secreting CCL24 trophoblasts could promote the growth of DSCs; pregnancy associated environments such as DSCs-trophoblasts contact and hormones increased local CCL24/CCR3, which means a beneficial factor for the process of decidualization in human early pregnancy.

Cyclosporine A enhances Th2 bias at the maternal-fetal interface in early human pregnancy with aid of the interaction between maternal and fetal cells

Our previous study has demonstrated that cyclosporine A (CsA) administration in vivo induces Th2 bias at the maternal-fetal interface, leading to improved murine pregnancy outcomes. Here, we investigated how CsA treatment in vitro induced Th2 bias at the human maternal-fetal interface in early pregnancy. The cell co-culture in vitro in different combination of component cells at the maternal-fetal interface was established to investigate the regulation of CsA on cytokine production from the interaction of these cells. It was found that interferon (IFN)-γ was produced only by decidual immune cells (DICs), and not by trophoblasts or decidual stromal cells (DSCs); all these cells secreted interleukin (IL)-4, IL-10, and tumor necrosis factor (TNF)-α. Treatment with CsA completely blocked IFN-γ production in DICs and inhibited TNF-α production in all examined cells. CsA increased IL-10 and IL-4 production in trophoblasts co-cultured with DSCs and DICs although CsA treatment did not affect IL-10 or IL-4 production in any of the cells when cultured alone. These results suggest that CsA promotes Th2 bias at the maternal-fetal interface by increasing Th2-type cytokine production in trophoblasts with the aid of DSCs and DICs, while inhibiting Th1-type cytokine production in DICs and TNF-α production in all investigated cells. Our study might be useful in clinical therapeutics for spontaneous pregnancy wastage and other pregnancy complications.

The decidual stromal cells-secreted CCL2 induces and maintains decidual leukocytes into Th2 bias in human early pregnancy

The precise mechanism of characteristic Th2 predominance at maternal-fetal interface remains unresolved. In the present study, we investigated roles of the decidua-derived CCL2 in Th2 predominance at maternal-fetal interface. FCM shows that 55% CD56(+)CD16(-)CD3(-) decidual NK, 52% CD4(+) T cells and 75% CD14(+) monocytes express CCR2. Recombinant human CCL2 (rhCCL2) and the decidual stromal cells (DSCs)-derived supernatant can enhance proliferation and inhibit apoptosis of these decidual leukocytes (DLCs), and promote Th2 cytokines production, IL-4 and IL-10, with an increase in GATA-3 transcription. They also inhibit the secretion of Th1 cytokines, TNF-α and IFN-γ, with a decrease in T-bet transcription It is concluded that the secreted CCL2 by decidual stromal cells increases GATA-3 transcription and decreases T-bet transcription in the decidual leukocytes, which contributes to Th2 polarization at maternal-fetal interface. Furthermore, the Th2 cytokines, IL-4 and IL-10, rather than Th1 cytokines, was shown to increase CCL2 secretion of DSC.

The CXCL12/CXCR4 axis is involved in the maintenance of Th2 bias at the maternal/fetal interface in early human pregnancy

The regulatory mechanism of Th2 bias at the maternal/fetal interface remains unclear. In this study, we characterized cytokine production in decidual stromal cells (DSCs), decidual immune cells (DICs) and embryo-derived trophoblast cells, and investigated the regulation of CXCL12/CXCR4 interaction on Th2 bias at the maternal/fetal interface in early human pregnancy. We found differential production of Th1-type and Th2-type cytokines by trophoblasts, DSCs and DICs. The secretion of these cytokines varied in different cell cocultures, conduced to Th2 bias. Flow cytometry showed that coculture of trophoblasts with DSCs and DICs significantly increased IL-4 and IL-10 production in trophoblasts, and IL-10 production in DSCs. However, the coculture of trophoblasts with DSCs and DICs significantly increased interferon (IFN)-γ expression in DSCs, and tumor-necrosis factor (TNF)-α expression in DICs. No change was seen in Th1-type cytokine production in trophoblasts, and in Th2-type cytokine production in DICs in all cocultures. Furthermore, pre-treatment with anti-CXCR4 neutralizing antibody upregulated the production of the Th1-type cytokines IFN-γ and TNF-α, and downregulated the production of the Th2-type cytokines IL-4 and IL-10, in trophoblasts, DSCs, DICs or their cocultures. Interestingly, rhCXCL12 inhibited production of the Th1-type cytokine TNF-α and enhanced the expression of the Th2-type cytokines such as IL-4 and IL-10 in DICs; this effect was abrogated by anti-CXCR4 antibody. Our present study has elucidated the individual contributions of component cells to the shaping of Th2 bias, and uncovered a complicated cross-talk via the CXCL12/CXCR4 signal at the maternal/fetal interface in early human pregnancy.

CXCL12/CXCR4 axis triggers the activation of EGF receptor and ERK signaling pathway in CsA-induced proliferation of human trophoblast cells

Introduction

Our previous study has demonstrated Cyclosporin A (CsA) promotes the proliferation of human trophoblast cells. Therefore, we further investigate the intracellular signaling pathway involved in the CsA-induced proliferation of human trophoblast cells.

Methods

Enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the regulation of CsA on CXCL12 secretion in human trophoblast cells. Immunofluorescence analysis and western blotting analysis were used to investigate the role of CXCL12/CXCR4 axis in the CsA-induced epidermal growth factor receptor (EGFR) phosphorylation in human trophoblast cells. 5-bromo-2′-deoxyuridine (BrdU) cell proliferation assay was performed to analyze the involvement of EGFR and its downstream extracellular signal-regulated protein kinase (ERK) signaling pathway in the CsA-induced proliferation of human trophoblast cells.

Results

Low concentration of CsA promoted the secretion of CXCL12, and recombinant human CXCL12 promoted the phosphorylation of EGFR in primary human trophoblast cells and choriocarcinoma cell line JEG-3. The inhibition of CXCL12 or CXCR4 by either neutralizing antibodies or small interfering RNA (siRNA) could completely block the CsA-induced EGFR phosphorylation. The CsA-induced proliferation of human trophoblast cells was effectively abrogated by the EGFR inhibitor AG1478 as well as the ERK inhibitor U0126, but not by the PI3K/PKB inhibitor LY294002. CsA promoted the activation of ERK in JEG-3 cells, which was markedly abrogated in the presence of CXCL12 siRNA, or CXCR4 siRNA, or AG1478.

Conclusions

CsA may promote EGFR activation via CXCL12/CXCR4 axis, and EGFR downstream ERK signaling pathway may be involved in the CsA-induced proliferation of human trophoblast cells.

CsA improves the trophoblasts invasiveness through strengthening the cross-talk of trophoblasts and decidual stromal cells mediated by CXCL12 and CD82 in early pregnancy

Our previous work has demonstrated that cyclosporin A (CsA) up-regulates but CD82 down-regulates the invasiveness of human trophoblasts. In the present study, we further investigated whether CsA can modulate the trophoblasts invasion through regulating the expression of CD82 in decidual stromal cells (DSCs). A co-culture model was established to investigate the effect of CsA on trophoblasts invasiveness. In-cell Western was performed to evaluate the expression of CD82, p53, β-catenin and the phosphorylation level of NF-κB p50 in DSCs. The secretion of CXCL12 of trophoblasts and DSCs was determined by enzyme-linked immunosorbent assay (ELISA). We found that CsA could not directly change the expression of CD82 in DSCs, but the CsA-treated trophoblasts significantly enhanced CD82 expression, NF-κB p50 phosphorylation and p53 expression, and decreased β-catenin expression in DSCs, and these effects could be abolished by anti-CXCL12 or CXCR4 neutralizing antibody. In addition, the invasiveness of trophoblast cells was markedly decreased after blocking CXCR4 of trophoblasts. Interestingly, when DSCs were pretreated with anti-CXCR4 neutralizing antibody, the invasiveness of trophoblast cells was enhanced in the coculture unit, and blocking CXCR4 on DSCs could reverse the decrease of trophoblasts invasiveness induced by CD82. Moreover, CsA further amplified these effects mediated by CXCL12 and CD82. Our results suggest that CsA not only promotes the trophoblasts invasiveness through stimulating the secretion of CXCL12, but also limits the invasiveness of trophoblasts by indirectly up-regulating the expression CD82. Therefore, CsA may contribute to the appropriate invasiveness of trophoblasts via strengthening the crosstalk between trophoblasts and DSCs.

CXCL12 controls over-invasion of trophoblasts via upregulating CD82 expression in DSCs at maternal-fetal interface of human early pregnancy in a paracrine manner

Tetraspanin CD82 has been identified as a potential contributor to controlling trophoblast invasiveness in human first-trimester pregnancy. However, it is unclear how the regulation of CD82 expression at maternal-fetal interface. The present study is to investigate the effect of the trophoblast-derived CXCL12 on CD82 expression in decidual stromal cells (DSCs) that in turn controls trophoblast cell invasiveness. In-cell Western was used to evaluate the expression of CD82 in DSCs. A co-culture model was established to investigate the reciprocal interaction between trophoblasts and DSCs via CXCL12/CXCR4 and CD82 expression. We found that both anti-CXCL12 and anti-CXCR4 neutralizing antibody can eliminate increase of CD82 expression in DSCs induced by the trophoblasts supernatant. Moreover, the invasiveness of trophoblasts pre-treated with anti-CXCR4 neutralizing antibody was significantly decreased. Interestingly, when DSCs were pre-treated with anti-CXCR4 neutralizing antibody, the trophoblasts invasiveness in the co-culture was enhanced, and thus anti-CXCR4 neutralizing antibody can reverse the decrease of trophoblasts invasiveness induced by CD82. The trophoblast cell-derived CXCL12 does not only increase the invasiveness in an autocrine manner, but also control the over-invasion of trophoblasts through promoting CD82 expression in DSCs in a paracrine manner, which maintains a physiological balance of human trophoblasts invasiveness via the cross-talk between trophoblasts and DSCs.

E-cadherin, as a negative regulator of invasive behavior of human trophoblast cells, is down-regulated by cyclosporin A via epidermal growth factor/extracellular signal-regulated protein kinase signaling pathway

Our previous study has demonstrated cyclosporin A (CsA) promotes the invasiveness of human first-trimester trophoblast cells. In the present study, we further investigated the intracellular signaling pathway responsible for the improvements in CsA-induced invasiveness of human trophoblast cells. We showed that CsA down-regulated E-cadherin transcription and translation in human primary cultured trophoblast cells and choriocarcinoma cell line JEG-3. U0126, an inhibitor of extracellular signal-regulated protein kinase (ERK), attenuated the CsA-induced transcriptional repressor SNAI2 (also called Slug) expression and restored E-cadherin expression inhibited by CsA in JEG-3 cells. We further demonstrated that CsA amplified epidermal growth factor (EGF)-stimulated EGF receptor (EGFR) tyrosine phosphorylation in JEG-3 cells, and inhibition of EGFR tyrosine phosphorylation by AG1478, an EGFR tyrosine kinase inhibitor, abolished the down-regulation of E-cadherin by CsA through ERK signaling pathway. Moreover, our data showed that E-cadherin expression was negatively correlated to the invasiveness of JEG-3 cells, and CsA could reverse the decreased invasiveness of JEG-3 cells that resulted from E-cadherin overexpression. In conclusion, these observations indicate that CsA may decrease E-cadherin expression via EGFR/ERK signaling pathway and, ultimately, contribute to the invasiveness improvement of human trophoblast cells.

Cyclosporin A improves murine pregnancy outcome in abortion-prone matings: involvement of CD80/86 and CD28/CTLA-4

Immune regulation during pregnancy is complex, and thus an optimal therapy for pregnancy complications is always a big challenge to reproductive medicine. Cyclosporin A (CsA), a potent immunosuppressant, prevents rejection of allografts by hosts, but little is known about the modulating effect of CsA on the materno-fetal relationship. Here, pregnant CBA/J females mated with DBA/2 males as an abortion-prone model were administered with CsA on day 4.5 of gestation, and the pregnant CBA/J females mated with BALB/c males were established as successful pregnancy control. It was demonstrated that administration of CsA at the window of implantation significantly up-regulated the expression of CTLA-4, while down-regulating the levels of CD80, CD86, and CD28 at the materno-fetal interface in the CBA/J×DBA/2 abortion-prone matings, and the embryo resorption rate of the abortion-prone matings reduced significantly after CsA treatment, implying that modulation of costimulatory molecule expression by CsA might contribute to preventing the fetus from maternal immune attack. In addition, treatment with CsA induced enhanced growth and reduced cell apoptosis of the murine trophoblast cells. Together, these findings indicate that CsA has a beneficial effect on the materno-fetal interface in abortion-prone matings, leading to a pregnancy outcome improvement, which might provide new therapeutics for spontaneous pregnancy wastage.

Regulation of C-C motif chemokine ligand 2 and its receptor in human decidual stromal cells by pregnancy-associated hormones in early gestation

BACKGROUND

Decidua is in close contact with the fetal trophoblasts, and involved in immune relationship of mother to fetus. However, the roles of decidua and decidual stromal cells (DSC) in materno-fetal immune regulation remain to be elucidated. In the present study, the expression and regulation of chemokines and their receptors in decidua and DSCs were investigated.

METHODS AND RESULTS

The transcription of 18 chemokine receptors in human first-trimester decidual tissue and DSC were first analysed by RT-PCR. Among these receptors, C-C motif chemokine receptor-2 (CCR2) was highly transcribed. It was demonstrated by RT-PCR and immunostaining that both CCR2 and its major ligand, C-C motif chemokine ligand 2 (CCL2, monocyte chemoattractant protein-1), were expressed in decidua and DSC. We then detected CCL2 in the supernatant of primary cultures of DSC by enzyme-linked immunosorbent assay. It was shown that DSC secreted CCL2 spontaneously and continuously over 72 h (21.72 +/- 2.34 ng/ml), and the CCR2 antagonist RS102895 and an inhibitor of the map kinase kinase/mitogen-activated protein kinase (ERK/MAPK) signal pathway decreased significantly the CCL2 secretion of DSC (both P < 0.05). We further studied effects of the pregnancy-associated hormones, estrogen, progesterone or HCG on CCL2 secretion by DSC. CCL2 secretion by DSC was up-regulated by estrogen, progesterone or HCG.

CONCLUSIONS

CCR2 and CCL2 are co-expressed by human first-trimester DSC and decidual tissue. CCL2 is secreted in an autocrine manner through the ERK/MAPK pathway, and is up-regulated by the pregnancy-associated hormones, estrogen, progesterone and HCG, which suggests that CCL2 may play an important role at materno-fetal interface.

Cyclosporine A induces titin expression via MAPK/ERK signalling and improves proliferative and invasive potential of human trophoblast cells

BACKGROUND

Cyclosporin A (CsA) is a powerful immunosuppressive that has been widely used to prevent organ rejection and to treat certain autoimmune diseases. Our previous study showed that CsA at low concentrations could promote proliferation and invasion, and inhibit apoptosis, of human first trimester trophoblasts. In the present study, we further explored the potential mechanism and signal pathway.

METHODS

After treatment of JAR cells with CsA, we screened the differentially expressed genes by suppression subtractive hybridization (SSH), and characterized the differentially expressed gene, titin, in human first-trimester trophoblasts by reverse transcription-polymerase chain reaction and Western blot. Mitogen-activated protein kinase (MAPK) activity was evaluated by ELISA.

RESULTS

CsA stimulated proliferation and invasion of human trophoblasts in a dose-dependent manner, and this appeared to be positive correlated with titin transcription, suggesting that CsA regulates biological functions of human trophoblast by inducing titin expression. Furthermore, the CsA treatment increased the MAPK activity, and blocking of the signaling pathway by Mitogen-activated protein MAPK (MEK) inhibitor, U0126, inhibited CsA-induced titin transcription in trophoblasts.

CONCLUSIONS

Our results indicate that titin expression is induced by CsA via activation of MAPK pathways and this may possibly be involved in promoting human trophoblast growth and invasiveness, which is beneficial to embryo viability.

Cyclosporin A increases expression of matrix metalloproteinase 9 and 2 and invasiveness in vitro of the first-trimester human trophoblast cells via the mitogen-activated protein kinase pathway

BACKGROUND

Cyclosporin A (CsA) is an immunosuppressent which is used for preventing allograft rejection. Little is known, however, about the effect of CsA on the materno-fetal relationship. Our aim was to probe into the effect of CsA on the invasiveness of human first-trimester trophoblast cells and explore possible molecules involved, with a view to providing a new therapeutic approach for pregnancy complications with trophoblast disorder.

METHODS

The effects of CsA on invasion of the first-trimester human trophoblasts were examined by matrigel invasion assay, and the transcription, translation and proteolytic activity of matrix metalloproteinase (MMP-9) and MMP-2 in these cells were estimated by RT-PCR, in-cell Western and zymography, respectively. The phosphorylation level of extracellular-signal related kinase (ERK) 1/2 in trophoblasts induced by CsA was also evaluated by in-cell Western.

RESULTS

CsA increased the invasive index of first-trimester human trophoblasts (P < 0.01), as well as the messenger RNA, protein levels (both P < 0.01) and proteolytic activity (P < 0.05) of MMP-9 and MMP-U0126, a mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibitor, inhibited the enhanced invasiveness and activity of MMP-9 and MMP-in these cells induced by CsA. In addition, CsA activated the ERK1/2 in a time-dependent manner.

CONCLUSIONS

CsA improves the invasiveness and activity of MMP 9 and MMP 2 in vitro of the first-trimester human trophoblast cells through activation of mitogen-activated protein kinase/extracellular-signal related kinase (ERK) 1/2 signaling pathway, which suggests this drug has a favorable modulation on the function of human first-trimester trophoblast cells.

Cyclosporin a improves pregnancy outcome by promoting functions of trophoblasts and inducing maternal tolerance to the allogeneic fetus in abortion-prone matings in the mouse

The embryo expresses paternal antigens foreign to the mother, and therefore has been viewed as a natural allograft. Cyclosporin A (CsA) is an immunosuppressant for preventing allograft rejection. Little is known, however, about the modulating effect of CsA on the materno-fetal relationship. In this study, pregnant CBA/J female mice mated with DBA/2 or BALB/c male mice as abortion-prone and normal pregnancy matings were administered, respectively, with CsA at Day 4 of gestation. We demonstrated that the administration of CsA at the window of implantation resulted in maternal T-cell tolerance to paternal antigen, and it improved pregnancy outcome in the CBA/J multiply sign in box DBA/2 abortion-prone matings. CsA administration enhanced Th2 and reduced Th1 cytokine production at the materno-fetal interface, and it expanded peripheral CD4(+)CD25(+) FOXP3(+) regulatory T cells in abortion-prone matings, implying development of Th2 bias and regulatory T cells. On the other hand, we observed that treatment with CsA led to enhanced growth and invasiveness of trophoblasts in the abortion-prone matings. Together, these findings indicate that CsA in lower dosages can induce materno-fetal tolerance and improve the biologic functions of trophoblast cells in the abortion-prone matings, leading to a successful pregnancy, which is useful in clinical therapeutics for spontaneous pregnancy wastage and other pregnancy complications.

Chemokine CXCL16, a scavenger receptor, induces proliferation and invasion of first-trimester human trophoblast cells in an autocrine manner

BACKGROUND

The aim of this study was to investigate whether CXCL16/CXCR6, a newly identified chemokine pair, is expressed in first-trimester human placenta and whether they affect the trophoblast cell biology, since we have found CXCR6 highly transcribed in first-trimester human trophoblast cells previously.

METHODS

We analysed the transcription and translation of CXCR6 and CXCL16 in purified first-trimester human trophoblast cells by real-time RT-PCR and immunochemical staining. We then examined the kinetic secretion of CXCL16 in the supernatant of primary-cultured trophoblast by enzyme-linked immunosorbent assay. We further investigated effects of CXCL16 on the proliferation and invasion of trophoblast cells in vitro.

RESULTS

We found the chemokine pair CXCL16/CXCR6 was transcribed and translated in first-trimester trophoblast cells and JAR line. In addition, the primary-cultured trophoblasts secreted CXCL16 spontaneously and continuously in 100-h culture. Treating trophoblasts with CXCL16 induced marked proliferation and invasion in vitro.

CONCLUSION

The findings from this study have demonstrated for the first time that CXCR6 and CXCL16 are co-expressed by first-trimester human trophoblast cells and stimulate their proliferation and invasion in an autocrine/paracrine manner. It suggests that CXCL16 plays important roles in human extravillous cytotrophoblast invasion and placentation.