MUC1 is involved in trophoblast transendothelial migration

Placental glycosylation senses the anti-angiogenic milieu induced by human sFLT1 during pregnancy

Abnormal placental angiogenesis during gestation resulting from high levels of anti-angiogenic factors, soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin, has been implicated in the progression of preeclampsia (PE). This heterogeneous syndrome (defined by hypertension with or without proteinuria after 20 weeks of pregnancy) remains a major global health burden with long-term consequences for both mothers and child. Previously, we showed that in vivo systemic human (hsFLT1) overexpression led to reduced placental efficiency and PE-like syndrome in mice. Galectins (gal-1, -3 and -9) are critical determinants of vascular adaptation to pregnancy and dysregulation of the galectin-glycan circuits is associated with the development of this life-threatening disease. In this study, we assessed the galectin-glycan networks at the maternal-fetal interface associated with the hsFLT1-induced PE in mice. We observed an increase on the maternal gal-1 expression in the decidua and junctional zone layers of the placenta derived from hs FLT1high pregnancies. In contrast, placental gal-3 and gal-9 expression were not sensitive to the hsFLT1 overexpression. In addition, O- and N-linked glycan expression, poly-LacNAc sequences and terminal sialylation were down-regulated in hsFLT1 high placentas. Thus, the gal-1-glycan axis appear to play an important role counteracting the anti-angiogenic status caused by sFLT1, becoming critical for vascular adaptation at the maternal-fetal interface.

Modified Sanliangsan Improved Sjogren's Syndrome Complicated with Interstitial Lung Disease by Suppressing Serum MUC1 Levels

OBJECTIVES

To clarify if the mechanism of Sanliangsan in improving Sjogren's syndrome complicated with interstitial lung disease (SS-ILD) involves MUC1 suppression, which is involved in SS-ILD pathogenesis.

METHODS

Fifty-six patients were randomly divided into two groups receiving Sanliangsan prescription (SP) therapy and conventional therapy (western medicine). In-depth transcriptome profiles from a large database of SS-ILD patients were collected and analyzed to identify candidate genes involved in SS pathogenesis. Clinical symptom scores, metabolic compositions, lung HRCT (high-resolution computed tomography) scores, and serum MUC1 levels were compared between the two groups before and after treatment. Network pharmacology, molecular docking, and ITC assays were performed to identify bioactive compounds of SP in improving SS. Metabolome analyzed the metabolic composition of serum associated with SS-ILD before and after SP treatment.

RESULTS

Transcriptome results identified the involvement of abnormal expression of genes relevant to the immune system, inflammatory responses, and signaling pathways. Numerous genes, including CD58, CD86, CTLA4, CXCL8, STAT1, and especially MUC1, were involved in SS pathogenesis and could be used to diagnose SS-ILD early. Both treatments improved the lung HRCT scores and clinical symptoms of SS-ILD. The SP therapy improved SS-ILD more effectively than conventional therapy. Moreover, Sanliangsan prescription therapy reduced serum MUC1 levels and restored the abnormal metabolisms, improving the abnormal inflammatory and immune responses of patients. Eugenol directly interacted with MUC1, suppressed related genes, and was the bioactive compound of SP. SP could partially restore the abnormal metabolisms associated with SS-ILD pathogenesis.

CONCLUSION

Based on conventional Western medicine treatment, modified Sanliangsan can significantly improve the clinical symptoms, signs, and lung function of patients; the mechanism may be due to eugenol and related to MUC1 regulation.

Human CD56+CD39+ dNK cells support fetal survival through controlling trophoblastic cell fate: immune mechanisms of recurrent early pregnancy loss

Decidual natural killer (dNK) cells are the most abundant immune cells at the maternal-fetal interface during early pregnancy in both mice and humans, and emerging single-cell transcriptomic studies have uncovered various human dNK subsets that are disrupted in patients experiencing recurrent early pregnancy loss (RPL) at early gestational stage, suggesting a connection between abnormal proportions or characteristics of dNK subsets and RPL pathogenesis. However, the functional mechanisms underlying this association remain unclear. Here, we established a mouse model by adoptively transferring human dNK cells into pregnant NOG (NOD/Shi-scid/IL-2Rγnull) mice, where human dNK cells predominantly homed into the uteri of recipients. Using this model, we observed a strong correlation between the properties of human dNK cells and pregnancy outcome. The transfer of dNK cells from RPL patients (dNK-RPL) remarkably worsened early pregnancy loss and impaired placental trophoblast cell differentiation in the recipients. These adverse effects were effectively reversed by transferring CD56+CD39+ dNK cells. Mechanistic studies revealed that CD56+CD39+ dNK subset facilitates early differentiation of mouse trophoblast stem cells (mTSCs) towards both invasive and syncytial pathways through secreting macrophage colony-stimulating factor (M-CSF). Administration of recombinant M-CSF to NOG mice transferred with dNK-RPL efficiently rescued the exacerbated pregnancy outcomes and fetal/placental development. Collectively, this study established a novel humanized mouse model featuring functional human dNK cells homing into the uteri of recipients and uncovered the pivotal role of M-CSF in fetal-supporting function of CD56+CD39+ dNK cells during early pregnancy, highlighting that M-CSF may be a previously unappreciated therapeutic target for intervening RPL.

MUC1 regulation in the left and right uterine horns and conceptus trophectoderm during the peri-implantation period of dromedary camel

Pregnancy maintenance in dromedary camels poses significant challenges, including early embryonic loss in the left uterine horn (LH) and unsuccessful pregnancy in the right uterine horn (RH), suggesting a potential asynchrony between conceptus signaling and uterine receptivity. The transition of the uterine epithelium from a pre-receptive to a receptive state requires a delicate balance of adhesion-promoting and anti-adhesion molecules. Mucin-1 (MUC1) acts as an anti-adhesive molecule on the uterine luminal (LE) and glandular (GE) epithelium. Downregulation of MUC1 is believed to be crucial for successful embryo attachment in various mammals. This study aimed to investigate the temporospatial expression of MUC1 in the LH and RH on Days 8, 10, and 12 pregnant dromedaries and their conceptuses. Quantitative real-time polymerase chain reaction (qrt-PCR), Western blot analysis, immunohistochemistry, and immunofluorescence techniques were employed to assess MUC1 expression at the mRNA and protein levels. The results demonstrated a reduction in MUC1 mRNA expression on Day 8, then increased on Day 10, followed by a decrease on Day 12 in LH. While the RH exhibited progressive increases, peaking on Day 12. However, MUC1 expression constantly exhibited higher levels in RH than in LH in all days. Two bands were detected at 150-kDa and 180-kDa, with the highest intensity observed on Day 10. Spatially, MUC1 was localized in the apical, cytoplasmic, and lumen of uterine glands only. MUC1 was barely detectable on Day 8 but gradually increased on Days 10 and 12 in both horns. Likewise, the RH exhibited higher MUC1 signals than the LH on Days 10 and 12. In the conceptuses, MUC1 mRNA increased on Day 8, peaked on Day 10, and declined on Day 12. Notably, MUC1 protein was detected in both the trophectoderm and endoderm, with high expression observed on Day 10 and reduced by Day 12. In conclusion, the decrease in MUC1 expression on Day 8 in the LH may be associated with maternal recognition of pregnancy (MRP), and the increase on Day 10 may related to embryo protection and movement, while the subsequent decrease on Day 12 could be linked to the embryo attachment and preparation for the implantation. Conversely, the increase of MUC1 in the RH implies a role in the anti-adhesion mechanism. These findings contribute to understanding MUC1's involvement in reproductive processes and provide insights into the complex mechanisms underlying successful pregnancy establishment and maintenance in dromedary camels.

Serum MUC3 Protein as a Novel Marker of Gestational Hypertensive Disorders

Background

This study aimed to investigate the serum levels of mucoprotein 3 in hypertensive diseases of pregnancy.

Methods

In total, 60 consecutive women with gestational hypertensive diseases (gestational hypertension (n = 20), severe preeclampsia (n = 20), HELLP syndrome (n = 20)) and 20 pregnant women without any gestational hypertensive diseases were included for this prospective controlled study. Serum MUC3 protein levels were measured with commercially available ELISA kits.

Results

Serum MUC3 protein level was the lowest in normal pregnant women (0.1047 ± 0.0295 ng/ml); while the severity of the disease increases, it significantly increased in severe preeclampsia (0.2700 ± 0.0199 ng/mL) and HELLP syndrome group (0.3494 ± 0.0455 ng/mL), but less in the gestational hypertension (0.2172 ± 0.0354 ng/mL) group. Mean serum MUC3 protein level differences were found the least in gestational hypertension (0.1125 ± 0.0107, p < 0.001), the most in HELLP syndrome (-0.2546 ± 0.0107, p < 0.001) compared with the pregnant control group.

Conclusion

The increase in serum MUC3 protein concentration in these women supported the argument that serum MUC3 protein may be used as a marker indicating the severity of the gestational hypertensive diseases.

Maternal high-fat diet during pregnancy with concurrent phthalate exposure leads to abnormal placentation

Di(2-ethylhexyl) phthalate (DEHP) is a synthetic chemical commonly used for its plasticizing capabilities. Because of the extensive production and use of DEHP, humans are exposed to this chemical daily. Diet is a significant exposure pathway and fatty food contain the highest level of phthalates. The impact on pregnancy following DEHP exposure and the associated interaction of high fat (HF) diet remains unknown. Here we report that exposure of pregnant mice to an environmentally relevant level of DEHP did not affect pregnancy. In contrast, mice fed a HF diet during gestation and exposed to the same level of DEHP display marked impairment in placental development, resulting in poor pregnancy outcomes. Our study further reveals that DEHP exposure combined with a HF diet interfere with the signaling pathway controlled by nuclear receptor PPARγ to adversely affect differentiation of trophoblast cells, leading to compromised vascularization and glucose transport in the placenta. Collectively, these findings demonstrate that maternal diet during pregnancy is a critical factor that determines whether exposure to an environmental toxicant results in impaired placental and fetal development, causing intrauterine growth restriction, fetal morbidity, and mortality.

Altered Glycosylation Contributes to Placental Dysfunction Upon Early Disruption of the NK Cell-DC Dynamics

Immune cells [e. g., dendritic cells (DC) and natural killer (NK) cells] are critical players during the pre-placentation stage for successful mammalian pregnancy. Proper placental and fetal development relies on balanced DC-NK cell interactions regulating immune cell homing, maternal vascular expansion, and trophoblast functions. Previously, we showed that in vivo disruption of the uterine NK cell-DC balance interferes with the decidualization process, with subsequent impact on placental and fetal development leading to fetal growth restriction. Glycans are essential determinants of reproductive health and the glycocode expressed in a particular compartment (e.g., placenta) is highly dependent on the cell type and its developmental and pathological state. Here, we aimed to investigate the maternal and placental glycovariation during the pre- and post-placentation period associated with disruption of the NK cell-DC dynamics during early pregnancy. We observed that depletion of NK cells was associated with significant increases of O- and N-linked glycosylation and sialylation in the decidual vascular zone during the pre-placental period, followed by downregulation of core 1 and poly-LacNAc extended O-glycans and increased expression of branched N-glycans affecting mainly the placental giant cells and spongiotrophoblasts of the junctional zone. On the other hand, expansion of DC induced a milder increase of Tn antigen (truncated form of mucin-type O-glycans) and branched N-glycan expression in the vascular zone, with only modest changes in the glycosylation pattern during the post-placentation period. In both groups, this spatiotemporal variation in the glycosylation pattern of the implantation site was accompanied by corresponding changes in galectin-1 expression. Our results show that pre- and post- placentation implantation sites have a differential glycopattern upon disruption of the NK cell-DC dynamics, suggesting that immune imbalance early in gestation impacts placentation and fetal development by directly influencing the placental glycocode.

Exploration of the regulation and control mechanisms of miR-145 in trophoblast cell proliferation and invasion

Preeclampsia (PE) is the leading cause of maternal and fetal mortality and morbidity. Furthermore, recent studies have reported that miR-145 within the preeclamptic trophoblast debris may cause the high blood pressure via interacting with the maternal endothelium. The aim of the present study was to investigate the functions of miR-145 in PE. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to assess the expression of miR-145 and mucin (MUC1), respectively. TargetScan, miRBase and miRWalk were used to predict the targets of miR-145. Constructed miR-145 mimic plasmids were transfected into HTR-8/SVneo cells for further experiments, including an MTT assay for cell proliferation, Transwell assay for cell invasion and flow cytometry for cell apoptosis analysis. Additionally, the luciferase reporter gene system was employed for target verification. The results demonstrated that miR-145 is downregulated and MUC1 is upregulated in PE tissues and cells compared with normal placenta tissues and cells. The correlation analysis suggests that the expression of miR-145 is negatively correlated with MUC1. Meanwhile, increased proliferation, enhanced invasion and decreased apoptosis of HTR-8/SVneo cells was observed in miR-145 mimic groups compared with mimic control group. Also, the decreased luciferase activity in the miR-145 mimic group indicates that MUC1 may be a target of miR-145. In summary, the results of the present study suggest that miR-145 may serve key roles in the regulation of trophoblast cell proliferation and invasion by targeting MUC1.

Superovulation at a specific stage of the estrous cycle determines the reproductive performance in mice

Inconsistent reproductive performance has been reported in superovulated mice. Hence, the aim of this study was to analyze the effect and possible mechanism of superovulation timing on mouse reproductive performance. The results showed that mice superovulated at the metestrous (23.08±6.08%) and diestrous stages (33.33±11.45%) presented significantly lower pregnancy rates compared with those superovulated at the estrous stage (66.67±9.20%). After superovulation at the proestrous and estrous stages, mucin 1 (MUC1) and let-7a/let-7b microRNA (miRNA) expression levels were significantly attenuated and enhanced on embryonic day 3.5 (E3.5), respectively, whereas no significant differences in the expression level were found in mice superovulated at the other two stages. A higher number of developing and Graafian follicles was observed in the ovarian sections 48h after the administration of pregnant mare serum gonadotropin (PMSG) at the proestrous and estrous stages. The sections from mice treated at the metestrous and diestrous stages, however, presented more corpora lutea. Therefore, mice superovulated at the proestrous and estrous stages exhibited the best pregnancy rates. Furthermore, the disordered expression of MUC1 and let-7a/let-7b miRNA in mice superovulated at the metestrous and diestrous stages may impair reproduction performance.

Adrenomedullin 2 (ADM2) Regulates Mucin 1 at the Maternal-Fetal Interface in Human Pregnancy

Association of an altered expression of placental mucin 1 (MUC1) with first-trimester spontaneous abortion and its regulation in placenta by an invasion-promoting peptide, adrenomedullin 2 (ADM2), is not known. The objective of this study was to assess 1) the association of MUC1 mRNA expression in the placental villi and decidua with first-trimester spontaneous abortion, 2) the effects of ADM2 on the expression of MUC1 in trophoblast cells in the presence or absence of hypoxia, 3) the effects of ADM2 on expression of MUC1 in decidual stromal cells (DSCs), and 4) if ADM2 regulates the expression of MUC1 and MMP2 protein in trophoblastic spheroids. Data demonstrate that 1) expression of MUC1 mRNA in villous tissue is higher in spontaneous abortion compared to age-matched electively terminated pregnancies (P > 0.05), 2) ADM2 decreases the expression of MUC1 mRNA and protein in trophoblast cells and spheroids with concomitant increases in MMP2 immunoreactivity in the spheroids, 3) ADM2 decreases hypoxia-induced increases in MUC1 immunoreactivity in trophoblast cells, 4) decidual MUC1 mRNA expression is lower in spontaneous compared to elective abortions (P < 0.05), and 5) DSCs express MUC1 mRNA and protein and ADM2 decreases the expression of MUC1 mRNA and protein in DSCs. Taken together, this study demonstrates that first-trimester spontaneous abortion is associated with increases in MUC1 expression in villi and decreases in the decidual tissues, and suggests that ADM2 may contribute to the physiology of embryo implantation and placental growth via increasing MMP2 and decreasing MUC1 expression to facilitate trophoblast invasion.

Interaction of extravillous trophoblast galectin-1 and mucin(s)-Is there a functional relevance?

In the course of embryo implantation extensive interaction of the trophoblast with uterine tissue is crucial for adequate trophoblast invasion. This interaction is highly controlled, and it has been pointed out that a specific glycocode and changes in glycosylation may be important for successful implantation and maintenance of pregnancy. Both uterine and trophoblast cells have been shown to express cell surface glycoconjugates and sugar binding proteins, such as mucins (MUC) and galectins (gals). An increasing number of studies have investigated potential candidates interacting in this process. However, knowledge about the biochemical nature of the interactions and their importance for trophoblast cell function, and, consequently, for pregnancy outcome are still lacking. This review is aimed at deliberating the possibility that mucins, as heavily glycosylated proteins, might be among the functionally relevant galectin ligands in human trophoblast, based on both published data and our original research.

Differential Effects of Sodium Butyrate and Lithium Chloride on Rhesus Monkey Trophoblast Differentiation

Trophoblast differentiation during early placental development is critical for successful pregnancy and aberrant differentiation causes preeclampsia and early pregnancy loss. During the first trimester, cytotrophoblasts are exposed to low oxygen tension (equivalent to~2%-3% O₂) and differentiation proceeds along an extravillous pathway (giving rise to invasive extravillous cytotrophoblasts) and a villous pathway (giving rise to multinucleated syncytiotrophoblast). Interstitial extravillous cytotrophoblasts invade the decidua, while endovascular extravillous cytotrophoblasts are involved in re-modelling uterine spiral arteries. We tested the idea that sodium butyrate (an epigenetic modulator) induces trophoblast differentiation in early gestation rhesus monkey trophoblasts through activation of the Wnt/β-catenin pathway. The results show that syncytiotrophoblast formation was increased by butyrate, accompanied by nuclear accumulation of β-catenin, and increased expression of EnvV2 and galectin-1 (two factors thought to be involved in trophoblast fusion). Surprisingly, the expression of GCM1 and syncytin-2 was not affected by sodium butyrate. When trophoblasts were incubated with lithium chloride, a GSK3 inhibitor that mimics Wnt activation, nuclear accumulation of β-catenin also occurred but differentiation into syncytiotrophoblast was not observed. Instead the cells differentiated to mononucleated spindle-shaped cells and showed molecular and behavioral characteristics of endovascular trophoblasts. Another highly specific inhibitor of GSK3, CHIR99021, failed to induce endovascular trophoblast characteristics. These observations suggest that activation of the Wnt/β-catenin pathway correlates with both trophoblast differentiation pathways, but that additional factors determine specific cell fate decisions. Other experiments suggested that the differential effects of sodium butyrate and lithium chloride might be explained by their effects on TNFα production. The results provide valuable tools to manipulate trophoblast differentiation in vitro and to better understand the differentiation pathways that occur during early gestation.

Nuclear localization of MUC1 extracellular domain in breast, head and neck, and colon cancer

Background

The glycoprotein MUC1 is overexpressed and underglycosylated in cancer cells. MUC1 is translated as a single polypeptide that undergoes autocleavage into 2 subunits (the extracellular domain and the cytoplasmic tail), and forms a stable heterodimer at the apical membrane of normal epithelial cells. The MUC1 cytoplasmic tail localizes to the cytoplasm of transformed cells and is targeted to the nucleus.

Aims

To study the expression of the MUC1 extracellular subunit in cell nuclei of neoplastic breast, head and neck, and colon samples.

Materials and Methods

330 primary tumor samples were analyzed: 166 invasive breast carcinomas, 127 head and neck tumors, and 47 colon tumors; 10 benign breast disease (BBD) and 40 normal specimens were also included. A standard immunohistochemical method with antigen retrieval was performed. Nuclear fractions from tissue homogenates and breast cancer cell lines (ZR-75, MDA-MB-231, MCF7, and T47D) were obtained and analyzed by Western blotting (WB). The anti-MUC1 extracellular subunit monoclonal antibody HMFG1 was used for immunohistochemistry.

Results

37/166 breast cancer specimens, 5/127 head and neck cancer specimens, 2/47 colon cancer samples, and 3/10 BBD samples showed immunohistochemical staining at the nuclear level. No nuclear reaction was detected in normal samples. By WB, breast and colon cancer purified nuclear fractions showed reactivity at 200 kDa in 3/30 breast and 3/20 colon cancer samples as well as purified nuclear fractions obtained from breast cancer cell lines.

Conclusions

This study shows that the MUC1 extracellular domain might be translocated to the cell nucleus in breast, head and neck, and colon cancer as well as BBD.

MicroRNA-199a mediates mucin 1 expression in mouse uterus during implantation

Embryo implantation is a complicated process involving interactions between the blastocyst and the luminal epithelium of the receptive uterus. Mucin 1 (MUC1) is an integral membrane glycoprotein expressed apically by secretory epithelial cells and the glandular epithelium in different organs, including the uterus. It is believed that loss of MUC1 on the surface of uterine epithelial cells is necessary for embryo implantation. The endogenous non-protein coding microRNAs (miRNAs) of 21-24 nucleotides are found in diverse organisms. It has been shown that miRNAs participate in a range of cellular processes by regulating gene expression at the post-transcriptional level. In the present study, the regulatory role of miRNA-199a on the expression of MUC1 in mouse uterus during implantation was investigated for its effect on embryo implantation. Western blotting and immunohistochemistry results showed high MUC1 expression on Day 0.5 and low expression by Day 4.5 of pregnancy. In contrast with MUC1 expression, increased miRNA-199a expression was evident at Day 4.5 of pregnancy, as measured by real-time reverse transcription-polymerase chain reaction. In addition, we demonstrated direct binding of miRNA-199a to the 3'-untranslated region of MUC1. Transfection of miRNA-199a into mouse uterine epithelial cells isolated from Day 0.5 of pregnancy also downregulated expression of MUC1. Therefore, the present study provides evidence that MUC1 is a direct target of miRNA-199a and suggests that development of novel strategies to facilitate a successful pregnancy and repair implantation failure humans may include miRNA.

Blockade of extracellular NM23 or its endothelial target slows breast cancer growth and metastasis

BACKGROUND

Nucleoside Diphosphate Kinase (NDPK), described as NM23 a metastasis suppressor, is found in the culture medium of cancer cells lines suggesting that the kinase may have an extracellular role. We propose that extracellular NM23 released from breast cancers in vivo stimulates tumor cell migration, proliferation and endothelial cell angiogenesis in support of metastasis development.

METHODS

NM23 in the bloodstream of immunocompromised mice carrying human triple-negative breast cancers or in breast cancer patients was measured by ELISA. Primary and metastatic tumor development, the impact of blockade of NM23 and/or its stimulation of nucleotide receptors were measured using in vivo imaging. NM23 expression data in the Curtis breast dataset was examined to test our hypothesis that NM23 may play a mechanistic role in breast cancer development.

RESULTS

SCID mice carrying metastatic MDA-MB-231Luc+ triple-negative human breast tumor cells elaborate NM23 into the circulation correlated with primary tumor growth. Treatment of mice with the NM23 inhibitor ellagic acid (EA) or the purinergic receptor antagonist MRS2179 slowed primary tumor growth. At 16 weeks following implantation, lung metastases were reduced in mice treated with EA, MRS2179 or the combination. Expression of NM23 in the Curtis breast dataset confirmed a likely role for NM23 in tumor metastasis.

CONCLUSIONS

Extracellular NM23 may constitute both a biomarker and a therapeutic target in the management of breast cancer.

Persistence of an immunoreactive MUC1 protein at the feto - maternal interface throughout pregnancy in the mare

A polyclonal human mucin-1 (MUC1) antibody was used to stain immunohistochemically for the presence of MUC1 on the endometrium and fetal membranes in mares between 20 and 309 days of gestation. Western blot analysis demonstrated the presence of a protein equivalent in size to a human MUC1 isoform, MUC1/Y, in equine endometrium, allantochorion and amnion. At all stages of gestation examined immunoreactivity to the MUC1 antibody was detected on the apical surface of the lumenal epithelium of the endometrium and the epithelium lining the mouths and apical regions of the endometrial glands. Furthermore, it persisted unchanged on the surface of the lumenal epithelium lying beneath the highly-invasive chorionic girdle component of the trophoblast before, during and after development of the endometrial cups. The MUC1 immunoreactive protein was also present on the trophoblast and other components of the fetal membranes during the post-fixation, pre-attachment period of gestation (20–40 days) and it persisted on the apical surface of the non-invasive trophoblast of the allantochorion before, during and after attachment, microvillous interdigitation and development of the microcotyledonary epitheliochorial placenta. Hence, the delayed placentation response in mares appears to occur independently of the persistence of an immunoreactive MUC1 protein at the feto–maternal interface.

The MUC1 extracellular domain subunit is found in nuclear speckles and associates with spliceosomes

MUC1 is a large transmembrane glycoprotein and oncogene expressed by epithelial cells and overexpressed and underglycosylated in cancer cells. The MUC1 cytoplasmic subunit (MUC1-C) can translocate to the nucleus and regulate gene expression. It is frequently assumed that the MUC1 extracellular subunit (MUC1-N) does not enter the nucleus. Based on an unexpected observation that MUC1 extracellular domain antibody produced an apparently nucleus-associated staining pattern in trophoblasts, we have tested the hypothesis that MUC1-N is expressed inside the nucleus. Three different antibodies were used to identify MUC1-N in normal epithelial cells and tissues as well as in several cancer cell lines. The results of immunofluorescence and confocal microscopy analyses as well as subcellular fractionation, Western blotting, and siRNA/shRNA studies, confirm that MUC1-N is found within nuclei of all cell types examined. More detailed examination of its intranuclear distribution using a proximity ligation assay, subcellular fractionation, and immunoprecipitation suggests that MUC1-N is located in nuclear speckles (interchromatin granule clusters) and closely associates with the spliceosome protein U2AF65. Nuclear localization of MUC1-N was abolished when cells were treated with RNase A and nuclear localization was altered when cells were incubated with the transcription inhibitor 5,6-dichloro-1-b-d-ribofuranosylbenzimidazole (DRB). While MUC1-N predominantly associated with speckles, MUC1-C was present in the nuclear matrix, nucleoli, and the nuclear periphery. In some nuclei, confocal microscopic analysis suggest that MUC1-C staining is located close to, but only partially overlaps, MUC1-N in speckles. However, only MUC1-N was found in isolated speckles by Western blotting. Also, MUC1-C and MUC1-N distributed differently during mitosis. These results suggest that MUC1-N translocates to the nucleus where it is expressed in nuclear speckles and that MUC1-N and MUC1-C have dissimilar intranuclear distribution patterns.

Why does the fallopian tube fail in ectopic pregnancy? The role of activins, inducible nitric oxide synthase, and MUC1 in ectopic implantation

OBJECTIVE

To investigate the role of activin-βA subunit, activin type II receptors, inducible nitric oxide synthase (iNOS), and MUC1 in the pathogenesis of ectopic pregnancy (EP) and their involvement in the determination of the implantation site.

DESIGN

Observational study.

SETTING

Academic unit of reproductive and developmental medicine.

PATIENT(S)

Four women at the luteal phase, three pseudopregnant women at the time of hysterectomy for benign disease, and 10 archived cases of EP. We collected 14 Fallopian tubes were collected from four women at the luteal phase and three pseudopregnant women at the time of hysterectomy for benign disease; specimens from implantation site, trophoblast and remote sites from the implantation site were collected from 10 archived cases of EP.

INTERVENTION(S)

Immunohistochemistry and quantitative reverse-transcriptase polymerase chain reaction (RT-PCR).

MAIN OUTCOME MEASURE(S)

Comparison of the expression of candidate molecules between the different groups.

RESULT(S)

The expression of activin-βA subunit, activin type II receptors, and iNOS was statistically significantly increased and expression of MUC1 statistically significantly decreased in tubes bearing an EP. There was no statistically significant difference in the expression of the candidate molecules between the implantation and remote sites. Candidate molecules were also expressed in the trophoblast.

CONCLUSION(S)

The pathological expression of candidate molecules by tubes bearing an EP is not involved in the determination of implantation site. Additionally, candidate molecules may play a role in the regulation of trophoblast cells in vivo during early pregnancy.

AP-1 transcription factors, mucin-type molecules and MMPs regulate the IL-11 mediated invasiveness of JEG-3 and HTR-8/SVneo trophoblastic cells

This study examines the IL-11 mediated activation of downstream signaling and expression of effector molecules to resolve the controversies associated with the IL-11 mediated regulation of the invasiveness of two commonly used trophoblastic cell models viz. JEG-3 and HTR-8/SVneo cells. It has been reported that IL-11 increases the invasiveness of JEG-3 cells while, reduces the invasiveness of HTR-8/SVneo cells. Invasion assay performed simultaneously for both the cell lines confirmed the above findings. In addition, HTR-8/SVneo cells showed a higher basal invasiveness than JEG-3 cells. Western blot showed the IL-11 mediated activation of STAT3(tyr705) and STAT1(tyr701) in both the cell lines. However, IL-11 activated the ERK1/2 phosphorylation in JEG-3 cells but, inhibited it in HTR-8/SVneo cells. Within 10 min of IL-11 treatment, p-STAT3(tyr705) was localized inside the nucleus of both the cell lines but, there was enhanced co-localization of protein inhibitor of activated STAT1/3 (PIAS1/3) and p-STAT3(tyr705) in HTR-8/SVneo cells and not in JEG-3 cells. This could be reason for the poor responsiveness of STAT3 responsive genes like mucin 1 (MUC1) in HTR-8/SVneo cells and not in JEG-3 cells. Further, microarray analysis of the IL-11 treated cells revealed differential responsiveness of JEG-3 as compared to HTR-8/SVneo cells. Several family of genes like activator protein-1 (AP-1) transcription factors (Jun and Fos), mucin-type molecules, MMP23B etc showed enhanced expression in IL-11 treated JEG-3 cells while, there was no response or decrease in their expression in IL-11 treated HTR-8/SVneo cells. Expression of these molecules was confirmed by quantitative RT-PCR. In addition, HTR-8/SVneo cells also showed a significant decrease in the expression of MMP2, MMP3 and MMP9 upon IL-11 treatment. Hence, IL-11 mediated differential activation of signaling and expression of effector molecules is responsible for the differential invasive response of JEG-3 and HTR-8/SVneo cells.

Altered global gene expressions of human placentae subjected to assisted reproductive technology treatments

BACKGROUND

Researchers are more and more concerning the safety of fetus or offspring derived from assisted reproductive technology (ART) treatment. As the placenta is a critical organ that sustains and protects the fetus, we hypothesize that altered global gene expression of the placenta subjected to ART manipulation may reflect changes associated with ART procedures and subsequently causal related to offspring health.

METHODS

Three term placenta samples were obtained from patients undergone in vitro fertilization and embryo transfer due to oviductal factors only. Other three control placentae were from those underwent normal pregnancy. A GeneChip Affymetrix HG-U133 Plus 2.0 Array was utilized to analyze the genes. Using qRT-PCR we certified microarray data from 10 dysregulated genes. Five genes were localized precisely in the placenta as per immunohistochemistry.

RESULTS

Twenty-six differentially expressed genes were identified in the ART-treated placentae: 17 up-regulated; 9 down-regulated. Eighteen of these were classified into six groups according to critical placental function: immune response; transmembrane transport; metabolism; oxidative stress; cell differentiation; and other functions. Genes involved in immune response, such as ERAP2 and STAT4, and those regulating cell differentiations, such as MUC1, were discerned to be differentially expressed. These gene products were expressed in the placental villus tissues, either in the cytoplasm or in the membrane of syncytiotrophoblastic cells.

CONCLUSION

To our knowledge, this is the first study in comparing differentially expressed genes in placentae from patients undergone ART treatment vs. those underwent normal pregnancy. Abnormal profiles of critical placental functioning genes, such as ERAP2, STAT4 and MUC1, may be valuable biomarkers to understand how the placenta affects fetal development and ART-derived offspring's health problems.

Surface Mucin-1 does not play a role in dendritic cell migration

Mucin-1 (MUC1) is a transmembrane glycoprotein that is upregulated upon maturation of dendritic cells (DC) in vitro or in vivo. One of the proposed functions of surface expressed MUC1 is its involvement in migration of cells. We hypothesized that MUC1 is involved in DC migration since mature DC (mDC) are highly migratory cells and MUC1 is upregulated on the surface of DC upon maturation. In this study we cultured DC using two maturation cocktails, one cocktail containing IL-4, GM-CSF, TNFalpha, PGE2, IL-1 beta and IL-6 (TP1,6-DC) and the other IL-13, GM-CSF, Ribomunyl and IFN-gamma (RI-DC). Both maturation cocktails render DC with a similar surface phenotype including CCR7 expression, but only the former induces a migratory capacity of DC to a CCL19 gradient. To analyze the role of surface-expression of MUC1 on TP1,6-DC, that are capable of migration, expression of MUC1 was prevented by adding an anti-MUC1 antibody (Ab) during the maturation process. Compared with matured DC in the absence of the Ab, no difference was observed in chemokine-induced migratory behaviour between the MUC1+ and MUC1- DC populations in a standard Transwell chemotaxis assay, nor in organotypic cultures. Our data clearly demonstrate that surface MUC1 on DC does not influence intrinsic cell-motility, nor is it involved in cell-cell and cell-matrix dependent migration.

Distinct genomic signatures of adaptation in pre- and postnatal environments during human evolution

The human genome evolution project seeks to reveal the genetic underpinnings of key phenotypic features that are distinctive of humans, such as a greatly enlarged cerebral cortex, slow development, and long life spans. This project has focused predominantly on genotypic changes during the 6-million-year descent from the last common ancestor (LCA) of humans and chimpanzees. Here, we argue that adaptive genotypic changes during earlier periods of evolutionary history also helped shape the distinctive human phenotype. Using comparative genome sequence data from 10 vertebrate species, we find a signature of human ancestry-specific adaptive evolution in 1,240 genes during their descent from the LCA with rodents. We also find that the signature of adaptive evolution is significantly different for highly expressed genes in human fetal and adult-stage tissues. Functional annotation clustering shows that on the ape stem lineage, an especially evident adaptively evolved biological pathway contains genes that function in mitochondria, are crucially involved in aerobic energy production, and are highly expressed in two energy-demanding tissues, heart and brain. Also, on this ape stem lineage, there was adaptive evolution among genes associated with human autoimmune and aging-related diseases. During more recent human descent, the adaptively evolving, highly expressed genes in fetal brain are involved in mediating neuronal connectivity. Comparing adaptively evolving genes from pre- and postnatal-stage tissues suggests that different selective pressures act on the development vs. the maintenance of the human phenotype.

Expression of MUC1 mucin in full-term pregnancy human placenta

PURPOSE

MUC1 mucin is a component of glycocalyx in human endometrium and may play an important role in generation of "receptive window" at embryo implantation. Considering that MUC1 expression in human placenta is changed during pregnancy, and that MUC1 structure and function are not completely known in this organ, we have undertaken isolation of this mucin and detection of glycan epitopes, since they are crucial for its properties.

MATERIAL AND METHODS

Samples of human placenta were homogenized and MUC1 was extracted in different conditions with the use of ionic or non-ionic detergents. Identification of this glycoprotein was performed by Western and lectin blotting, after its purification on Sepharose 4B column.

RESULTS

The best extraction of MUC1 glycoprotein was achieved with a non-ionic detergent, Triton X-100. Reactions with anti-MUC1 antibody showed a few glycoforms with molecular weights between 116 and 205 kDa, with the most visible glycoform approximating 205 kDa. Reactions with lectins enabled detection of carbohydrate antigens, such as T and Tn with sialic acid linked by alpha2, 3 and to a lesser extent by alpha2, 6 bond.

CONCLUSION

MUC1 mucin is present in several glycoforms on the maternal side of human placenta after term delivery. They contain short glycan structures, similar to some tumor carbohydrate antigens.