The role of the matrix metalloproteinases in human endometrial and ovarian cycles

MMP2 and MMP9 are associated with the pathogenesis of recurrent pregnancy loss through protein expression rather than genetic polymorphism

Matrix metalloproteinases (MMPs) degrade extracellular matrix proteins and are important for placenta formation during early pregnancy. Recurrent pregnancy loss (RPL) is associated with abnormalities in endometrial extracellular matrix remodeling. This study aimed to elucidate the roles of MMP2 and MMP9 in RPL pathogenesis. In total, 295 women with a history of RPL and 101 controls were included in this genetic study. Genotype analysis was performed using polymerase chain reaction (PCR) restriction fragment length polymorphisms. For proteolytic analysis, decidua and villi were collected from 10 RPL-miscarried women with normal fetal chromosomes (NC) and 19 women with fetal chromosome aberrations (AC). The expression of MMP2 and MMP9 in the decidua and villi was measured by IHC and ELISA. All samples were collected after obtaining informed consent. There were no statistically significant differences in MMP2-735 C/T and MMP9-1562 C/T frequencies between women with RPL and the controls. There was no significant difference in MMP2 expression levels in the villi; however, MMP9 expression was significantly higher in normal fetal chromosomes. In the decidua, the expression of MMP2 in the NC group was significantly lower, and MMP9 in the NC group was significantly higher than in the AC group. Although no differences in MMP2-735 C/T and MMP9-1562 C/T gene polymorphisms were observed in the present study, it is suggested that differences at the protein level are involved in the pathogenesis of RPL since MMP expression is not only regulated by genes but also by local inflammation and various inductive signals.

Immunohistochemical study of MMP-2, MMP-9, EGFR and IL-8 in decidual and trophoblastic specimens of recurrent pregnancy loss cases

BACKGROUND AND AIM

Unexplained recurrent pregnancy loss has been a a challenging research task to experts since there is no explicit pathophysiological mechanism and therefore, the treatment remains elusive. Immunological imbalance and morphological abnormalities are under investigation. This study aims to evaluate the implication of MMP-2, MMP-9, EGFR, and IL-8 in recurrent pregnancy loss cases.

MATERIALS & METHODS

The study was carried out through comparison among two groups; the unexplained miscarriage group which consisted of 22 women, and the control group consisted of 18 women, who had electively terminated their pregnancies. Both groups were in the first trimester of gestation. The specimens included the trophoblast, decidua basalis, and decidua parietalis. The study was conducted via immunohistochemical methods. Antibodies were used against MMP-2, MMP-9, EGFR, and IL-8. The results were presented at a contingency table and were statistically analyzed with the Chi-Square Test (X²).

RESULTS

There were remarkable disparities in some cases in the comparison of the two groups. MMP-9 was detected significantly high in recurrent pregnancy loss (RPL) cases, both on trophoblastic and decidual specimens (p-value < .00001), MMP-2 displayed no difference among the two groups (mild to moderate detection on trophoblast and almost negative on decidual tissues). EGFR was highly detected in trophoblastic tissue (p-value = .014). IL-8 detection was particularly different in both trophoblast and decidua parietalis of the two groups (p-value < .01).

CONCLUSION

The study revealed both morphological and immunological dysregulations that might participate in the RPL pathogenesis.

Drastic induction of MMP-7 by cortisol in the human amnion: implications for membrane rupture at parturition

Preterm premature rupture of fetal membranes precedes 30-40% of preterm births. Activation of matrix metalloproteases (MMPs) is the one of the major causes of extracellular matrix (ECM) degradation in membrane rupture. Increased cortisol, regenerated by 11β-hydroxysteroid dehydrogenase 1 in the amnion at parturition, is known to participate in a number of parturition-pertinent events. However, whether cortisol has a role in the regulation of MMPs in the membranes is not known. Here, we addressed this issue using human amnion tissue, the most tensile layer of the membranes. RNA-sequencing revealed that cortisol induced MMP7 expression dramatically in amnion fibroblasts, which was confirmed by real-time quantitative RT-PCR and Western blotting analysis in cortisol-treated amnion explants and fibroblasts. Measurement of collagen IV α5 chain (COL4A5), a substrate for MMP-7, showed that cortisol reduced its extracellular abundance, which was blocked by an antibody against MMP-7. Moreover, increased MMP-7 but decreased COL4A5 abundance was observed in the amnion tissue following labor-initiated spontaneous rupture of membranes. Mechanistic studies showed that cortisol increased the phosphorylation of c-Jun and the expression of c-Fos, the 2 major components of activated protein 1 (AP-1), respectively. The knocking down of c-Fos or c-Jun significantly attenuated the induction of MMP7 expression by cortisol. Chromatin immunoprecipitation assays showed that cortisol stimulated the enrichment of c-Fos and c-Jun at the AP-1 binding site in the MMP7 promoter. The data suggest that induction of MMP7 by cortisol via AP-1 may be a contributing factor to ECM degradation in membrane rupture at parturition.-Wang, L.-Y., Wang, W.-S., Wang, Y.-W., Lu, J.-W., Lu, Y., Zhang, C.-Y., Li, W.-J., Sun, K., Ying, H. Drastic induction of MMP-7 by cortisol in the human amnion: implications for membrane rupture at parturition.

Potential roles of metalloproteinases of endometrium-derived exosomes in embryo-maternal crosstalk during implantation

During embryo implantation, crosstalk between the endometrial epithelium and the blastocyst, especially the trophoblasts, is a prerequisite for successful implantation. During this crosstalk, various molecular and functional changes occur to promote synchrony between the embryo and the endometrium as well as the uterine cavity microenvironment. In the past few years, growing evidence has shown that endometrium-derived exosomes play pivotal roles in the embryonic-maternal crosstalk during implantation, although the exact mechanism of this crosstalk has yet to be determined. The presence of metalloproteinases has been reported in endometrium-derived exosomes, implying the importance of these enzymes in exosome-based crosstalk. Thus, in this review, we describe the potential roles of the metalloproteinases of endometrium-derived exosomes in promoting embryo attachment and implantation. This study could provide a better understanding of the potential roles of exosomal metalloproteinases in embryo implantation and pave the way for developing novel exosome-based regulatory agents to support early pregnancy.

Uterine Expression of NDRG4 Is Induced by Estrogen and Up-Regulated during Embryo Implantation Process in Mice

Embryo implantation is an essential step for the establishment of pregnancy and dynamically regulated by estrogen and progesterone. NDRG4 (N-myc down-regulated gene 4) is a tumor suppressor that participates in cell survival, tumor invasion and angiogenesis. The objective of this study was to preliminarily explore the role of NDRG4 in embryo implantation. By immunohistochemistry (IHC) and quantitive RT-PCR (qRT-PCR), we found that uterine expression of NDRG4 was increased along with puberal development, and its expression in adult females reached the peak at the estrus stage during the estrus cycle. Furthermore, uterine NDRG4 expression was significantly induced by the treatment of estradiol (E₂) both in pre-puberty females and ovariectomized adult females. Uterine expression pattern of NDRG4 during the peri-implantation period in mice was determined by IHC, qRT-PCR and Western blot. It was observed that NDRG4 expression was up-regulated during the implantation process, and its expression level at the implantation sites was significantly higher than that at the inter-implantation sites. Meanwhile, an increased expression in NDRG4 was associated with artificial decidualization as well as the activation of delayed implantation. By qRT-PCR and Western blot, we found that the in vitro decidualization of endometrial stromal cells (ESCs) was accompanied by up-regulation of NDRG4 expression, whereas knockdown of its expression in these cells by siRNA inhibited the decidualization process. In addition, Western blot analysis showed that NDRG4 protein expression was decreased in human villus tissues of recurrent miscarriage (RM) patients compared to normal pregnant women. Collectively, these data suggested that uterine NDRG4 expression could be induced by estrogen, and NDRG4 might play an important role during early pregnancy.

Gene expression profiling of bovine peripartal placentomes: detection of molecular pathways potentially involved in the release of foetal membranes

The mechanisms underlying detachment of foetal membranes after birth in cows are still unclear. To address this problem in a systematic manner, we performed the first holistic transcriptome study of bovine placentomes antepartum (AP;n=4 cows) and intrapartum (IP;n=4 cows) using Affymetrix GeneChip Bovine Genome Arrays. Three placentomes were extracted from each cow, and tissue samples from the contact zones of the placentomes (foeto-maternal units) were recovered by systematic random sampling and processed for RNA extraction and for stereological quantification of cellular composition. Statistical analysis of microarray data (false discovery rate 1%) revealed 759 mRNAs with at least twofold higher levels in the samples of the AP group, whereas 514 mRNAs showed higher levels in the IP group. The differentially expressed genes were classified according to biological processes and molecular functions using the Functional Annotation Clustering tool of the DAVID Bioinformatics Resources. Genes with higher mRNA levels in the AP group were nearly completely related to mitotic cell cycle and tissue differentiation. During parturition, a complete shift occurred because the genes with higher mRNA levels in IP were nearly all related to three different physiological processes/complexes: i) apoptosis, ii) degradation of extra cellular matrix and iii) innate immune response, which play a fundamental role in placental detachment. These results are an excellent basis for future studies investigating the molecular basis of retained foetal membranes.

Oocyte specific oolemmal SAS1B involved in sperm binding through intra-acrosomal SLLP1 during fertilization

Molecular mechanisms by which fertilization competent acrosome-reacted sperm bind to the oolemma remain uncharacterized. To identify oolemmal binding partner(s) for sperm acrosomal ligands, affinity panning was performed with mouse oocyte lysates using sperm acrosomal protein, SLLP1 as a target. An oocyte specific membrane metalloproteinase, SAS1B (Sperm Acrosomal SLLP1 Binding), was identified as a SLLP1 binding partner. cDNA cloning revealed six SAS1B splice variants, each containing a zinc binding active site and a putative transmembrane domain, with signal peptides in three variants. SAS1B transcripts were ovary specific. SAS1B protein was first detected in early secondary follicles in day 3 ovaries. Immunofluorescence localized SAS1B to the microvillar oolemma of M2 oocytes. After fertilization, SAS1B decreased on the oolemma and became virtually undetectable in blastocysts. In transfected CHO-K1 cells SAS1B localized to the surface of unpermeabilized cells. Recombinant and native SLLP1 co-localized with SAS1B to the microvillar domain of ovulated M2 oocytes. Molecular interactions between mouse SLLP1 and SAS1B were demonstrated by surface plasmon resonance, far-western, yeast two-hybrid, recombinant- and native-co-IP analyses. SAS1B bound to SLLP1 with high affinity. SAS1B had protease activity, and SAS1B protein or antibody significantly inhibited fertilization. SAS1B knockout female mice showed a 34% reduction in fertility. The study identified SAS1B-SLLP1 as a pair of novel sperm-egg binding partners involving the oolemma and intra-acrosomal compartment during fertilization.

Expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and its related extracellular matrix degrading enzymes in the endometrium during estrous cycle and early gestation in cattle

BACKGROUND

Extracellular matrix metalloproteinase inducer (EMMPRIN) regulates several biological functions involving the modulation of cell behaviors via cell-cell and cell-matrix interactions. According to its diverse functions, we hypothesized that EMMPRIN may play an important role in endometrial remodeling and establishment of pregnancy in cow.

METHODS

In this study, endometrial tissues from the cyclic cows during before ovulation, after ovulation and middle of estrous cycle; and pregnant endometrial tissues from Day 19 to 35 of gestation have been used. Expression of mRNA was analyzed by RT-PCR, qPCR and in situ hybridization whereas protein expression by immunohistochemistry and western blot analysis.

RESULTS

EMMPRIN mRNA was expressed in both cyclic and pregnant endometrium and significantly higher in the endometrium at Day 35 of gestation than the cyclic endometrium. In Western blot analysis, an approximately 65 kDa band was detected in the endometrium, and approximately 51 kDa in the cultured bovine epithelial cells and BT-1 cells, respectively. Both in situ hybridization and immunohistochemistry data showed that EMMPRIN was primarily expressed in luminal and glandular epithelium with strong staining on Day 19 conceptus. At Day 19 of gestation, expression of EMMPRIN mRNA on luminal epithelium was decreased than that observed at middle of estrous cycle, however, on Day 30 of gestation, slightly increased expression was found at the site of placentation. Expression of matrix metalloproteinase-2 (MMP-2) and MMP-14 mRNA were mainly detected in stroma and their expression also decreased at Day 19 of gestation however it was also expressed at the site of placentation at Day 30 of gestation as observed for EMMPRIN. Expression of MMP-1 or -9 mRNA was very low and was below the detection limit in the cyclic and pregnant endometrium.

CONCLUSION

EMMPRIN from the luminal epithelium may regulate the expression of stromal MMP-2 and -14 suggesting its crucial role in adhesion and fusion of embryo to luminal epithelium by directly itself through physiological tissues remodeling and developmental process, and/or stimulating MMPs to compensate endometrial functions.

Matrix metalloproteinase-2 is elevated in midtrimester amniotic fluid prior to the development of preeclampsia

OBJECTIVE

To evaluate levels of matrix metalloproteinases (MMP) and their inhibitors (TIMP) in second trimester amniotic fluid of women with hypertensive disorders compared to normotensive women.

STUDY DESIGN

Amniotic fluid was obtained from 133 women undergoing genetic second trimester amniocentesis. Zymography was performed for MMP characterization and an MMP-2 ELISA kit was used to determine MMP-2 levels. TIMP-2 expression was evaluated using western blot.

RESULTS

Mean amniotic fluid MMP-2 and TIMP-2 levels were significantly higher in women who developed a hypertensive disorder compared to normotensive women (P < 0.0004 and P < 0.01, respectively). When subdivided into subgroups, amniotic fluid from women who eventually developed preeclampsia or superimposed preeclampsia showed significantly higher MMP-2 levels than normotensive women (P < 0.05). However, no statistical difference in MMP-2 levels was found between patients with gestational hypertension and normotensive patients.

CONCLUSION

Higher amniotic fluid MMP-2 and TIMP-2 levels are found in women who eventually develop preeclampsia.

Expression and localization of transcription factor Ets-1 in the rat ovary during the estrous cycle and pregnancy

OBJECTIVE

To examine the expression and localization of Ets-1 in the rat ovary during the estrous cycle and pregnancy, and to investigate its effects on ovarian function.

DESIGN

Prospective, randomized study.

SETTING

Department of Physiology at Harbin Medical University.

ANIMAL(S)

Pubertal female Wistar rats.

INTERVENTION(S)

Vaginal smears were taken daily from female rats to determine the stage of the estrous cycle. Pregnancies were achieved by caging female and male rats together overnight. Ovaries were collected from both cycling and pregnant rats for tissue sectioning and RNA and protein extractions.

MAIN OUTCOME MEASURE(S)

Real-time quantitative polymerase chain reaction, Western blot, in situ hybridization, and immunohistochemistry were performed to investigate the expression and localization of Ets-1 messenger RNA (mRNA) and protein in the rat ovary during the estrous cycle and pregnancy.

RESULT(S)

During the estrous cycle, the levels of Ets-1 mRNA and protein expression increased during the follicular phase, achieving their highest measurements at proestrus and lowest at metestrus. The expression of Ets-1 mRNA and protein fluctuated during pregnancy, increasing during early pregnancy, then decreasing during mid-pregnancy, and again increasing until parturition. Ets-1 mRNA and protein were present throughout the estrous cycle and pregnancy, principally localized in follicles of various sizes and in the corpus luteum.

CONCLUSION(S)

Ets-1 may participate and play an important role in the regulation of follicular development, corpus luteum formation, maintenance, and regression.

Myocardial Matrix Remodeling and the Matrix Metalloproteinases: Influence on Cardiac Form and Function

It is now becoming apparent that dynamic changes occur within the interstitium that directly contribute to adverse myocardial remodeling following myocardial infarction (MI), with hypertensive heart disease and with intrinsic myocardial disease such as cardiomyopathy. Furthermore, a family of matrix proteases, the matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs), has been recognized to play an important role in matrix remodeling in these cardiac disease states. The purpose of this review is fivefold: 1) to examine and redefine the myocardial matrix as a critical and dynamic entity with respect to the remodeling process encountered with MI, hypertension, or cardiomyopathic disease; 2) present the remarkable progress that has been made with respect to MMP/TIMP biology and how it relates to myocardial matrix remodeling; 3) to evaluate critical translational/clinical studies that have provided a cause-effect relationship between alterations in MMP/TIMP regulation and myocardial matrix remodeling; 4) to provide a critical review and analysis of current diagnostic, prognostic, and pharmacological approaches that utilized our basic understanding of MMP/TIMPs in the context of cardiac disease; and 5) most importantly, to dispel the historical belief that the myocardial matrix is a passive structure and supplant this belief that the regulation of matrix protease pathways such as the MMPs and TIMPs will likely yield a new avenue of diagnostic and therapeutic strategies for myocardial remodeling and the progression to heart failure.

Characterization of EN-1078D, a poorly differentiated human endometrial carcinoma cell line: a novel tool to study endometrial invasion in vitro

BACKGROUND

To date, tools to study metastasis in endometrial cancers are insufficiently developed. The aim of this study was to characterize the cell line EN-1078D, a new endometrial carcinoma cell line derived from a metastasis to the ovary.

METHODS AND RESULTS

Cells were characterized using cytology, transmission electron microscopy, karyotyping and morphological appearance in culture. Molecular features were determined by RT-PCR, Western Blot, FISH and sequencing. MTT proliferation assays were performed to investigate the sensitivity of EN-1078D to anticancer agents such as cisplatin and doxorubicin. Also, subcutaneous and intravenous injections in nude mice were done to test the tumorigenic and metastatic properties of EN-1078D cells. Our results indicate that EN-1078D cells express both oestrogen receptors isoforms (ER alpha and ER beta) and also low levels of progesterone receptor B (PR-B). In addition, this cell line expresses high levels of MMP-2 and MMP-14 mRNA, low levels of TIMP-1 and TIMP-2 transcripts and no detectable levels of MMP-9 mRNA. Moreover, all nude mice developed tumors by subcutaneous injections and cell invasion was observed in vitro in response to TGF-beta 3. Her-2/neu was not overamplified but mutations in the C-2 domain of PTEN gene as well as codon 12 of the K-Ras gene were found. Finally, EN-1078D shows sensitivity to drugs commonly used in chemotherapy such as cisplatin and doxorubicin: IC50 of 2.8 microM of cisplatin after 72 hours of exposure and 0.54 microM of doxorubicin after 48 hours.

CONCLUSION

Taken together, these results suggest that EN-1078D will be an excellent tool to study the properties of metastatic endometrial cancer cells in vitro and their regulation by sex steroids.

Quantitative cellular and molecular analysis of the effect of progesterone withdrawal in a murine model of decidualization

The endometrium is a dynamic tissue that undergoes periodic growth, remodeling and breakdown under the influence of ovarian steroid hormones. To investigate the molecular mechanisms underlying these processes, we used a murine model to mimic the decidualization and regression observed in humans. Ovariectomized mice were treated sequentially with steroid hormones, and subsequently, to induce decidualization, oil was injected into the uterine lumen. The animals were then divided into progesterone-maintained and progesterone-withdrawal groups. In the latter group, a process similar to menstruation was induced. The uterine tissues were collected at several time-points after the induction of decidualization. Histological analysis demonstrated that decidualization and tissue degeneration were successfully induced with similar features to those observed during the human menstrual cycle. Immunohistochemical, morphometric, and microarray-based techniques were used to study the cellular and molecular changes. The volume fractions of leukocytes, macrophages, and neutrophils, but not endothelial cells, increased in decidualized uteri and decreased after major tissue degradation was completed. The microarray data show that the levels of many transcripts that encode immune-related factors changed during the time-course used for this model, and the transcript levels of many of these factors paralleled the changes observed in the volume fractions of the immune cells. The results of the present study suggest that this model is a useful alternative to the use of non-human primates. Our findings also show that immune cells are recruited into the menstruating endometrium, and that immune-related genes are regulated in the uterus throughout menstruation.

Genetic and developmental basis of cichlid trophic diversity

Cichlids have undergone extensive evolutionary modifications of their feeding apparatus, making them an ideal model to study the factors that underlie craniofacial diversity. Recent studies have provided critical insights into the molecular mechanisms that have contributed to the origin and maintenance of cichlid trophic diversity. We review this body of work, which shows that the cichlid jaw is regulated by a few genes of major additive effect, and is composed of modules that have evolved under strong divergent selection. Adaptive variation in cichlid jaw shape is evident early in development and is associated with allelic variation in and expression of bmp4. Modulating this growth factor in the experimentally tractable zebrafish model reproduces natural variation in cichlid jaw shape, supporting a role for bmp4 in craniofacial evolution. These data demonstrate the utility of the cichlid jaw as a model for studying the genetic and developmental basis of evolutionary changes in craniofacial morphology.

The effect of serum from women with preeclampsia on JAR (trophoblast-like) cell line

OBJECTIVE

Pathologic placentation has been implicated in the pathogenesis of preeclamsia. We sought to assess the effect serum obtained from women with preeclampsia would have on JAR human choriocarcinoma cells regarding growth, invasiveness, and matrix metalloproteinase (MMP) secretion as compared to normotensive pregnant woman.

METHODS

Blood was collected from 11 healthy pregnant women and from10 patients with preeclampsia at 28-33 weeks of gestation. The JAR human choriocarcinoma cell line was cultured in the presence of 10% serum obtained from each group. Cell proliferation, invasiveness, and MMP secretion was measured using a cell proliferation kit, the Matrigel (BD Biosciences, Beit-Ha'Emek, Israel) invasion assay, and gel zymography, respectively.

RESULTS

Cell growth increased by 6% when exposed to serum from patients with preeclampsia compared to 30% from controls (P <.01). Trophoblast invasion was significantly (P <.01) reduced in the preeclampsia group (21 +/- 1.9%) compared to controls (27 +/- 2.5%). Valid MMP-2 secretion was reduced by 51% in the preeclampsia group compared to controls (P <.05).

CONCLUSION

Serum obtained from women with preeclampsia contains a factor or factors that exhibit an inhibitory effect on JAR trophoblast cell proliferation, invasiveness, and MMP-2 secretion. These factors may be involved in the pathologic placentation associated with the pathogenesis of preeclampsia.

Inhibiting matrix metalloproteinases with prinomastat produces abnormalities in fetal growth and development in rats

BACKGROUND

Matrix metalloproteinases (MMPs) play key roles in remodeling of the extracellular matrix during embryogenesis and fetal development. The objective of this study was to determine the effects of prinomastat, a potent selective MMP inhibitor, on fetal growth and development.

METHODS

Prinomastat (25, 100, 250 mg/kg/day, p.o.) was administered to pregnant female Sprague-Dawley rats on gestational days (GD) 6-17. A Cesarian section was carried out on GD 20 and the fetuses were evaluated for viability and skeletal and soft tissue abnormalities.

RESULTS

Prinomastat treatment at the 250 mg/kg/day dose produced a decrease in body weight and food consumption in the dams. A dose-dependent increase in post-implantation loss was observed in the 100 and 250 mg/kg/day-dose groups, resulting in only 22% of the dams having viable litters for evaluation at the 250 mg/kg/day dose. Fetal skeletal tissue variations and malformations were present in all prinomastat treated groups and their frequency increased with dose. Variations and malformation in fetal soft tissue were also increased at the 100 and 250 mg/kg/day doses. Prinomastat also interfered with fetal growth of rat embryo cultures in vitro.

CONCLUSIONS

These data confirm that MMP inhibition has a profound effect on fetal growth and development in vivo and in vitro.

Human trophoblast function during the implantation process

The implantation process involves complex and synchronized molecular and cellular events between the uterus and the implanting embryo. These events are regulated by paracrine and autocrine factors. Trophoblast invasion and migration through the uterine wall is mediated by molecular and cellular interactions, controlled by the trophoblast and the maternal microenvironment. This review is focused on the molecular constituents of the human trophoblast, their actions and interactions, including interrelations with the uterine endometrium.