The matrix metalloproteinase system: changes, regulation, and impact throughout the ovarian and uterine reproductive cycle

Estrogen receptor β controls MMP-19 expression in mouse ovaries during ovulation

Estrogen receptor beta (ERβ/ESR2) has a central role in mouse ovaries, as ERβ knockout (BERKO) mice are subfertile due to an increase in fibrosis around the maturing follicle and a decrease in blood supply. This has a consequence that these follicles rarely rupture to release the mature oocyte. Matrix metalloproteinases (MMPs) are modulators of the extracellular matrix, and the expression of one specific MMP, MMP-19, is normally increased in granulosa cells during their maturation until ovulation. In this study, we demonstrate that MMP-19 levels are downregulated in BERKO mouse ovaries. Using human MCF-7 cells that overexpress ERβ, we could identify MMP-19 to be a transcriptional target of ligand-bound activated ERβ acting on a specificity protein-1 binding site. These data provide a molecular explanation for the observed follicle rupture defect that contributes to the subfertility of female BERKO mice.

A Follicle Rupture Assay Reveals an Essential Role for Follicular Adrenergic Signaling in Drosophila Ovulation

Ovulation is essential for the propagation of the species and involves a proteolytic degradation of the follicle wall for the release of the fertilizable oocyte. However, the precise mechanisms for regulating these proteolytic events are largely unknown. Work from our lab and others have shown that there are several parallels between Drosophila and mammalian ovulation at both the cellular and molecular levels. During ovulation in Drosophila, posterior follicle cells surrounding a mature oocyte are selectively degraded and the residual follicle cells remain in the ovary to form a corpus luteum after follicle rupture. Like in mammals, this rupturing process also depends on matrix metalloproteinase 2 (Mmp2) activity localized at the posterior end of mature follicles, where oocytes exit. In the present study, we show that Mmp2 activity is regulated by the octopaminergic signaling in mature follicle cells. Exogenous octopamine (OA; equivalent to norepinephrine, NE) is sufficient to induce follicle rupture when isolated mature follicles are cultured ex vivo, in the absence of the oviduct or ovarian muscle sheath. Knocking down the alpha-like adrenergic receptor Oamb (Octoampine receptor in mushroom bodies) in mature follicle cells prevents OA-induced follicle rupture ex vivo and ovulation in vivo. We also show that follicular OA-Oamb signaling induces Mmp2 enzymatic activation but not Mmp2 protein expression, likely via intracellular Ca²⁺ as the second messenger. Our work develops a novel ex vivo follicle rupture assay and demonstrates the role for follicular adrenergic signaling in Mmp2 activation and ovulation in Drosophila, which is likely conserved in other species.

Ovulation is the process of releasing fertilizable oocytes from the ovary and is essential for metazoan reproduction. Our recent work has demonstrated principles governing ovulation process that are highly conserved across species, such that both mammals and Drosophila utilize matrix metalloproteinase (Mmp) to degrade extracellular matrix and weaken the follicle wall for follicle rupture. However, a fundamental question remaining in the field is how Mmp activity is precisely regulated during ovulation. This paper reports that Drosophila octopamine (OA), the insect equivalent of norepinephrine (NE), is the signal to induce Mmp activity through activating its receptor Oamb on mature follicle cells and that this may induce ovulation. These findings allow us to develop the first ex vivo follicle rupture assay for Drosophila, which gives us unprecedented ability to characterize the entire follicle rupturing process ex vivo and to identify essential factors for ovulation. Furthermore, we show that NE partially fulfills OA’s role in inducing follicle rupture ex vivo, indicating that follicular adrenergic signal is a conserved signal to regulating Mmp activity and ovulation. Our work not only sheds light on the long-standing question of Mmp regulation, but also may lead to a better understanding of Mmp and NE linked pathological processes including cancer metastasis and polycystic ovary syndrome.

Expression and regulative function of tissue inhibitor of metalloproteinase 3 in the goat ovary and its role in cultured granulosa cells

Tissue inhibitor of metalloproteinase 3 (TIMP3) played a key role in female reproduction. However, its expression and function in goat are still unclear. In the present study, the full-length cDNA of goat TIMP3 was cloned from adult goat ovary; meanwhile, we demonstrated that putative TIMP3 protein shared a highly conserved amino acid sequence with known mammalian homologs. Real-time PCR results showed that TIMP3 was widely expressed in the tissues of adult goat. In the ovary, increasing expression of TIMP3 mRNA was discovered during the growth process of follicle and corpus luteum. Immunohistochemistry results suggested that TIMP3 protein existed in oocytes of all types of follicles, corpus luteum and granulosa and theca cells of primary, secondary, and antral but not primordial follicles. In vitro, human chorionic gonadotropin (hCG) stimulated the expression of TIMP3 in goat granulosa cells. hCG-induced TIMP3 mRNA expression was reduced by the inhibitors of protein kinase A, protein kinase C, MAPK kinase, or p38 kinase. Functionally, over-expression of TIMP3 significantly increased apoptosis and decreased the viability of cultured granulosa cells. Knockdown of TIMP3 could decrease hCG-induced progesterone secretion and the mRNA abundance of key steroidogenic enzymes (StAR, p450scc and HSD3B) as well as ECM proteins (DCN and FN). These findings provided evidence that the hCG induced expression of TIMP3 may play an important role in regulating goat granulosa cell survival and steroidogenesis.

The involvement of osteopontin and matrix metalloproteinase- 9 in the migration of endometrial epithelial cells in patients with endometriosis

BACKGROUND

Endometriosis, which shares certain characteristics with cancers, may cause abnormal expression of proteins involved in cell migration. Endometrial epithelial cells (EECs) are believed to play an important role in endometriotic migration. The aim of this study was to investigate the relationship between the expression of osteopontin (OPN) and matrix metalloproteinase-9 (MMP-9) in endometriotic migration.

METHODS

We performed primary culture of EECs and investigated the expression of OPN and MMP-9 in EECs regulated by 17beta-estradiol (E2). OPN-specific siRNA interference was used to down-regulate OPN and to explore the corresponding change in MMP-9 expression. Real-time RT-PCR, western blot analysis and flow cytometry were used to determine the expression levels of OPN and MMP-9. Gelatin zymography was performed to observe the enzymatic activity of MMP-9 in conditioned media. Transwell and wound scratch assays were performed to investigate the migration ability of EECs.

RESULTS

The expression levels of OPN and MMP-9 in normal EECs (NEECs) were inferior to those in EECs from patients with endometriosis (EEECs). The expression levels of OPN and MMP-9 from stage III/IV EEECs and secretory-phase EECs were higher than those of stage I/II EEECs or proliferative-phase EECs. The expression levels of OPN and MMP-9 in EEECs were increased by E2 treatment and remarkably decreased by siRNA interference. Active MMP-9 expression increased with E2 treatment and decreased with siRNA treatment in EEECs compared with the same treatments in NEECs. The migratory abilities of EEECs were enhanced after cells were treated with E2; in contrast, these abilities were reduced by siRNA interference. In NEECs, active MMP-9 and cellular migration abilities were only minimally influenced by E2 and siRNA treatment.

CONCLUSIONS

The present study suggests that the up-regulation of MMP-9 via activation of OPN induced by estrogen may correlate with the migration of endometrial epithelial cells in patients with endometriosis.

Characterization of MMP-9 gene from a normalized cDNA library of kidney tissue of yellow catfish (Pelteobagrus fulvidraco)

Matrix metalloproteinase-9 (MMP-9), one of members of the MMP family, is important for the cleaving of structural extracellular matrix (ECM) molecules and involved in inflammatory processes. In this study, MMP-9 cDNA was isolated and characterized from a normalized cDNA library of kidney tissue of yellow catfish (designated as YcMMP-9). The complete sequence of YcMMP-9 cDNA consisted of 2561 nucleotides. The open reading frame potentially encoded a protein of 685 amino acids with a calculated molecular mass of approximately 77.182 kDa. Amino acid sequence of YcMMP-9 have typical characteristics of MMP-9 family and showed highest identity (85.3%) to channel catfish MMP-9. The YcMMP-9 genomic DNA contains 13 exons and 12 introns. Quantitative RT-PCR (qRT-PCR) analysis showed that YcMMP-9 mRNA was constitutively expressed in all examined tissues in normal fish with high expression in head kidney, trunk kidney, blood, and spleen. However, expression of YcMMP-9 mRNA was induced by Aeromonas hydrophila stimulation, especially in these four tissues mentioned above. It indicated that YcMMP-9 was involved in innate immune responses against bacterial infection.

LH-Induced Steroidogenesis in the Mouse Ovary, but Not Testis, Requires Matrix Metalloproteinase 2- and 9-Mediated Cleavage of Upregulated EGF Receptor Ligands

Oocyte maturation and cumulus cell expansion depend on luteinizing hormone (LH)-mediated upregulation of membrane-bound epidermal growth factor (EGF)-like ligands, including amphiregulin, epiregulin, and betacellulin. These ligands then transactivate the EGF receptor (EGFR) after release by matrix metalloproteinases (MMPs). However, direct measurement of released EGF-like ligands or MMPs from granulosa cells has not been formally evaluated, nor has direct identification of responsible MMPs. Here we address these issues by analyzing LH-induced steroidogenesis, which is also MMP and EGFR dependent, in freshly isolated mouse primary granulosa cells. We demonstrate a correlation between amphiregulin and epiregulin mRNA induction and steroid production in LH-treated granulosa cells as well as in ovaries of human chorionic gonadotropin-treated mice. In contrast, LH does not alter Mmp1, Mmp2, Mmp3, Mmp8, Mmp9, or Adam17 mRNA expression. We demonstrate that, in primary mouse granulosa cells, LH triggers release of soluble amphiregulin that correlates with steroid production, both of which are blocked by MMP2/9 inhibition, confirming that MMP2/9 likely regulates LH-induced amphiregulin release and downstream processes. Notably, LH does not alter secretion of MMP2/9 from primary granulosa cells, nor does it modulate MMP activity. These findings indicate that, in the ovary, LH dictates EGFR-mediated processes not by regulating MMPs, but instead by increasing EGF-like ligand availability. In contrast, LH stimulation of primary mouse Leydig cells does not induce EGF-like ligand expression or require MMP2/9 for steroidogenesis, confirming marked differences in LH receptor-induced processes in the testes. Our results suggest that MMP inhibition may be a means of attenuating excess ovarian steroid production in diseases like polycystic ovary syndrome.

Rapid changes in ovarian mRNA induced by brief photostimulation in Siberian hamsters (Phodopus sungorus)

This study sought to characterize the rapid intraovarian mRNA response of key folliculogenic factors that may contribute to the restoration of folliculogenesis during 2-10 days of photostimulation in Siberian hamsters. Adult hamsters were exposed to short photoperiod (8L:16D) for 14 weeks (SD). A subset were then transferred to long photoperiod (16L:8D) for 2 (PT day-2), 4 (PT day-4), or 10 days (PT day-10). Quantitative real-time PCR was used to measure intraovarian mRNA expression of: gonadotropin releasing hormone (GnRH), follicle stimulating hormone β-subunit (FSHβ-subunit), luteinizing hormone β-subunit (LHβ-subunit), FSH and LH receptors, estrogen receptors α and β (Esr1 and Esr2), matrix metalloproteinase (MMP)-2 and -9, anti-Müllerian hormone (AMH), inhibin-α subunit, fibroblast growth factor-2 (FGF-2) and proliferating cell nuclear antigen (PCNA). Compared to SD, plasma FSH concentrations increased on PT day-4 and the number of antral follicles and corpora lutea increased on PT day-10. FSHR and inhibin-α mRNA expression also increased on PT day-4, whereas LHR and proliferation marker PCNA both increased on PT day-10 as compared to SD. Esr1 mRNA increased on PT day-2 and remained significantly increased as compared to SD, whereas Esr1 mRNA increased only on PT day-2, similar to FGF-2 and MMP-2 results. No differences were observed in mRNA expression in ovarian GnRH, FSHβ- and LHβ-subunits, AMH, and MMP-9 mRNA with 2-10 days of photostimulation. Rapid increases in intraovarian FSHR and inhibin-α mRNA and antral follicle/corpora lutea numbers suggest that the ovary is primed to react quickly to the FSH released in response to brief periods of photostimulation.

Leptin promotes human endometriotic cell migration and invasion by up-regulating MMP-2 through the JAK2/STAT3 signaling pathway

Despite evidence that leptin may play a role in the pathogenesis of endometriosis, the specific function of leptin in the migration and invasion of endometriotic cells is not well characterized. In this study, we investigated the effect of leptin on the migration, invasion and matrix metalloproteinase (MMP) expression levels of human endometriotic cells. We found that leptin stimulated the migration and invasion of endometriotic cells (11Z, 12Z and 22B) in a dose-dependent manner. Leptin receptor (ObR) siRNA significantly inhibited the migration and invasion induced by leptin in 11Z and 12Z cells. Leptin-induced migration and invasion were significantly attenuated by pretreatment with SB-3CT, a specific gelatinase (MMP-2 and MMP-9) inhibitor. In addition, leptin-induced increases in the mRNA and protein expression and enzyme activity of MMP-2 in 11Z and 12Z cells. Selectively inhibiting MMP-2 using siRNA and an inhibitor (GM6003), impaired the ability of leptin to stimulate the migration and invasion of endometriotic cells, suggesting that MMP-2 plays an essential role in leptin-induced migration and invasion. Janus Kinase 2/Signal Transducer and Activator of Transcription 3 (JAK2/STAT3) inhibitor (AG490) significantly inhibited the migration, invasion and MMP-2 expression induced by leptin in endometriotic cells. Furthermore, the Extracellular signal-Regulated Kinase inhibitor PD98059 neutralized the migration and invasion promoting effects of leptin. Taken together, these results suggest that leptin may contribute to the migration and invasion abilities of endometriotic cells via the up-regulation of MMP-2 through an ObR-dependent JAK2/STAT3 signaling pathway.

Matrix metalloproteinase inhibition influences aspects of photoperiod stimulated ovarian recrudescence in Siberian hamsters

Blocking matrix metalloproteinase (MMP) activity in vivo with inhibitor GM6001 impedes photostimulated ovarian recrudescence in photoregressed Siberian hamsters. Since direct and indirect effects of MMPs influence a myriad of ovarian functions, we investigated the effect of in vivo MMP inhibition during recrudescence on ovarian mRNA expression of steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD), Cyp19a1 aromatase, epidermal growth factor receptor (EGFR), amphiregulin (Areg), estrogen receptors (Esr1 and Esr2), tissue inhibitors of MMPs (TIMP-1,-2,-3), proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor A (VEGFA), its receptor VEGFR-2, and angiopoietin-2 (Ang-2). Female Siberian hamsters were randomly assigned to one of four photoperiod groups: stimulatory long (LD) or inhibitory short (SD) photoperiods, or transferred from SD to LD for 2 weeks (post-transfer, PT). Half of the PT hamsters were injected (ip) daily with GM6001 (PTG). SD exposure reduced ovarian StAR, 3β-HSD, Cyp19a1, Esr1, Esr2, TIMPs 2-3, PCNA, VEGFR-2 and Ang-2 mRNA expression (p<0.05), and 2 weeks of photostimulation restored mRNA expression of 3β-HSD and PCNA and increased Areg and VEGFA mRNA expression in the PT group. GM6001 treatment during photostimulation (PTG) increased TIMP-1, -2 and -3 and PCNA mRNA, but inhibited Areg mRNA expression compared to PT. Neither photoperiod nor GM6001 altered EGFR expression. Results of this study suggest that in vivo inhibition of MMP activity by GM6001 may impede ovarian recrudescence, particularly follicular growth, in two ways: (1) directly by partially inhibiting the release of EGFR ligands like Areg, thereby potentially affecting EGFR activation and its downstream pathway, and (2) indirectly by its effect on TIMPs which themselves can affect proliferation, angiogenesis and follicular growth.

Ovarian cancer: involvement of the matrix metalloproteinases

Ovarian cancer is the leading cause of death from gynecologic malignancies. One of the reasons for the high mortality rate associated with ovarian cancer is its late diagnosis, which often occurs after the cancer has metastasized throughout the peritoneal cavity. Cancer metastasis is facilitated by the remodeling of the extracellular tumor matrix by a family of proteolytic enzymes known as the matrix metalloproteinases (MMPs). There are 23 members of the MMP family, many of which have been reported to be associated with ovarian cancer. In the current paradigm, ovarian tumor cells and the surrounding stromal cells stimulate the synthesis and/or activation of various MMPs to aid in tumor growth, invasion, and eventual metastasis. The present review sheds light on the different MMPs in the various types of ovarian cancer and on their impact on the progression of this gynecologic malignancy.

Effect of hormonal contraception on the function of plasmacytoid dendritic cells and distribution of immune cell populations in the female reproductive tract

OBJECTIVE

Epidemiological evidence suggests an association between the use of hormonal contraception and an increased risk of acquiring sexually transmitted diseases including HIV-1. We sought to elucidate the biological mechanisms underlying the effect of hormonal contraception on the immune system.

DESIGN

Cross-sectional study.

METHODS

To delineate the biological mechanisms underlying the effect of hormonal contraceptives on the immune system, we analyzed the functional capacity of circulating plasmacytoid dendritic cells (pDCs), the distribution of vaginal immune cell populations, and the systemic and genital levels of immune mediators in women using depot medroxyprogesterone acetate (DMPA), NuvaRing, or combined oral contraceptives (COC).

RESULTS

The use of DMPA or NuvaRing was associated with reduced capacity of circulating pDCs to produce interferon (IFN)-α and tumor necrosis (TNF-α) in response to TLR-9 stimulation. Systemic levels of IFN-α and cervicovaginal fluid levels of IFN-α, CXCL10, monocyte chemotactic protein-1, and granulocyte-colony stimulating factor were significantly lower in DMPA users compared to control volunteers not using hormonal contraception. The density of CD207 Langerhans cells in the vaginal epithelium was reduced in NuvaRing and combined oral contraceptive users but not in DMPA users.

CONCLUSIONS

The presented evidence suggests that the use of some types of hormonal contraception is associated with reduced functional capacity of circulating pDCs and altered immune environment in the female reproductive tract.

The role of eicosanoids in 17α, 20β-dihydroxy-4-pregnen-3-one-induced ovulation and spawning in Danio rerio

This study employed a hormone bioassay to characterize the eicosanoids involved in zebrafish ovulation and spawning, in particular the prostaglandin (PG) products of cyclooxygenase (COX) metabolism and the leukotriene (LT) products of lipoxygenase (LOX) metabolism. Exposure to the teleost progestogen 17α, 20β-dihydroxy-4-pregnen-3-one (17,20βP) induced ovulation, but not spawning, in solitary females and both ovulation and spawning in male-female pairs. Transcription of the eicosanoid-synthesizing enzymes cytosolic phospholipase A2 (cPLA(2)) and COX-2 increased and LTC(4) synthase decreased in peri-ovulatory ovaries of 17,20βP-exposed fish. Ovarian PGF(2α) levels increased post-spawning in 17,20βP-exposed fish, but there was no difference in LTB(4) or LTC(4). Pre-exposure to cPLA(2) or LOX inhibitors reduced 17,20βP-induced ovulation rates, while a COX inhibitor had no effect on ovulation or spawning. Collectively, these findings suggest that eicosanoids, in particular LOX metabolites, mediate 17,20βP-induced ovulation in zebrafish. COX metabolites also appear to be involved in ovulation and spawning but their role remains undefined.

Elevated matrix metalloproteinase-8 in saliva and serum in polycystic ovary syndrome and association with gingival inflammation

This study aimed to investigate the levels of matrix metalloproteinase-8 (MMP-8) and tissue inhibitors of MMP-1 (TIMP-1) in saliva and serum samples of women with polycystic ovary syndrome (PCOS; n = 80) and matched systemically healthy controls ( n = 45), with varying degrees of gingival inflammation. Salivary levels of MMP-8 and the MMP-8/TIMP-1 ratio were significantly elevated in women with PCOS, who also exhibited more gingivitis than systemically healthy women. No major changes were observed in salivary TIMP-1 levels with regard to PCOS. Serum levels of MMP-8 and the MMP-8/TIMP-1 ratio were significantly higher in women with PCOS, irrespective of the presence of gingivitis, while there were no differences in TIMP-1 levels. A positive correlation was indicated between probing depth, bleeding on probing, plaque index and salivary or serum MMP-8 levels or MMP-8/TIMP-1 ratio in the case of PCOS, while a negative such correlation was revealed for TIMP-1 in systemically healthy women. Increased levels of MMP-8 in saliva and serum seem to be more pronounced in women with PCOS, and potentiated in the presence of gingival inflammation. Alterations in MMP/TIMP system triggered by local and systemic inflammation may be implicated in the pathogenesis of PCOS, or the deterioration of its clinical presentation.

Matrix metalloproteinase 2 is required for ovulation and corpus luteum formation in Drosophila

Ovulation is critical for successful reproduction and correlates with ovarian cancer risk, yet genetic studies of ovulation have been limited. It has long been thought that the mechanism controlling ovulation is highly divergent due to speciation and fast evolution. Using genetic tools available in Drosophila, we now report that ovulation in Drosophila strongly resembles mammalian ovulation at both the cellular and molecular levels. Just one of up to 32 mature follicles per ovary pair loses posterior follicle cells (“trimming”) and protrudes into the oviduct, showing that a selection process prefigures ovulation. Follicle cells that remain after egg release form a “corpus luteum (CL)” at the end of the ovariole, develop yellowish pigmentation, and express genes encoding steroid hormone biosynthetic enzymes that are required for full fertility. Finally, matrix metalloproteinase 2 (Mmp2), a type of protease thought to facilitate mammalian ovulation, is expressed in mature follicle and CL cells. Mmp2 activity is genetically required for trimming, ovulation and CL formation. Our studies provide new insights into the regulation of Drosophila ovulation and establish Drosophila as a model for genetically investigating ovulation in diverse organisms, including mammals.

Sexual reproduction is thought to be a highly divergent process due to fast evolution and speciation. For example, sperm from one species can seldom fertilize eggs from another species, indicating that different molecular machinery for fertilization is applied in different species. In contrast to this divergent view, ovulation, the process of liberating mature eggs from the ovary, is a general phenomenon throughout the Metazoa. We provide evidence that basic mechanisms of ovulation are conserved. Like mammalian follicles, Drosophila follicles consist of single oocytes surrounded by a layer of follicle cells. Drosophila follicles degrade their posterior follicle cells to allow the oocyte to rupture into the oviduct during ovulation. The residual postovulatory follicles reside in the ovary, accumulate yellowish pigmentation, and produce the steroid hormone ecdysone, features which resemble the mammalian corpus luteum. We also showed that matrix metalloproteinase, a type of proteinase proposed to degrade the mammalian follicle wall during ovulation, is required in Drosophila for posterior follicle cell degradation and ovulation. These findings are particularly important because this simple genetic model system will speed up the identification of many conserved regulators required for regulating matrix metalloproteinase activity and ovulation in human, processes that influence ovarian cancer formation and cancer metastasis.

Functional consequences of copy number variants in miscarriage

Background

The presence of unique copy number variations (CNVs) in miscarriages suggests that their integral genes have a role in maintaining early pregnancy. In our previous work, we identified 19 unique CNVs in ~40% of studied euploid miscarriages, which were predominantly familial in origin. In our current work, we assessed their relevance to miscarriage by expression analysis of 14 genes integral to CNVs in available miscarriage chorionic villi. As familial CNVs could cause miscarriage due to imprinting effect, we investigated the allelic expression of one of the genes (TIMP2) previously suggested to be maternally expressed in placenta and involved in placental remodelling and embryo development.

Results

Six out of fourteen genes had detectable expression in villi and for three genes the RNA and protein expression was altered due to maternal CNVs. These genes were integral to duplication on Xp22.2 (TRAPPC2 and OFD1) or disrupted by a duplication mapping to 17q25.3 (TIMP2). RNA and protein expression was increased for TRAPPC2 and OFD1 and reduced for TIMP2 in carrier miscarriages. The three genes have roles in processes important for pregnancy development such as extracellular matrix homeostasis (TIMP2 and TRAPPC2) and cilia function (OFD1). TIMP2 allelic expression was not affected by the CNV in miscarriages in comparison to control elective terminations.

Conclusion

We propose that functional studies of CNVs could help determine if and how the miscarriage CNVs affect the expression of integral genes. In case of parental CNVs, assessment of the function of their integral genes in parental reproductive tissues should be also considered in the future, especially if they affect processes relevant for pregnancy development and support.

Electronic supplementary material

The online version of this article (doi:10.1186/s13039-015-0109-8) contains supplementary material, which is available to authorized users.

Induction of proteinases in the human preovulatory follicle of the menstrual cycle by human chorionic gonadotropin

OBJECTIVE

To explore the temporal expression in granulosa and theca cells of key members of the MMP and ADAMTS families across the periovulatory period in women to gain insight into their possible roles during ovulation and early luteinization.

DESIGN

Experimental prospective clinical study and laboratory-based investigation.

SETTING

University medical center and private IVF center.

ANIMAL AND PATIENT(S)

Thirty-eight premenopausal women undergoing surgery for tubal ligation and six premenopausal women undergoing assisted reproductive techniques.

INTERVENTION(S)

Administration of hCG and harvesting of follicles by laparoscopy and collection of granulosa-lutein cells at oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Expression of mRNA for matrix metalloproteinase (MMPs) and the A disintegrin and metalloproteinase with thrombospondin-like motifs (ADAMTS) in human granulosa cells and theca cells collected across the periovulatory period of the menstrual cycle and in cultured granulosa-lutein cells after hCG. Localization of MMPs and ADAMTSs by immunohistochemistry.

RESULT(S)

Expression of MMP1 and MMP19 mRNA increased in both granulosa and theca cells after hCG administration. ADAMTS1 and ADAMTS9 mRNA increased in granulosa cells after hCG treatment, however, thecal cell expression for ADAMTS1 was unchanged, while ADAMTS9 expression was decreased. Expression of MMP8 and MMP13 mRNA was unchanged. Immunohistochemistry confirmed the localization of MMP1, MMP19, ADAMTS1, and ADAMTS9 to the granulosa and thecal cell layers.

CONCLUSION(S)

The collection of the dominant follicle throughout the periovulatory period has allowed the identification of proteolytic remodeling enzymes in the granulosa and theca compartments that may be critically involved in human ovulation. These proteinases may work in concert to regulate breakdown of the follicular wall and release of the oocyte.

Dynamic reciprocity between cells and their microenvironment in reproduction

Dynamic reciprocity (DR) refers to the ongoing, bidirectional interaction between cells and their microenvironment, specifically the extracellular matrix (ECM). The continuous remodeling of the ECM exerts mechanical force on cells and modifies biochemical mediators near the cell membrane, thereby initiating cell-signaling cascades that produce changes in gene expression and cell behavior. Cellular changes, in turn, affect the composition and organization of ECM components. These continuous interactions are the fundamental principle behind DR, and its critical role throughout development and adult tissue homeostasis has been extensively investigated. While DR in the mammary gland has been well described, we provide direct evidence that similar dynamic interactions occur in other areas of reproductive biology as well. In order to establish the importance of DR in the adaptive functioning of the female reproductive tract, we present our most current understanding of DR in reproductive tissues, exploring the mammary gland, ovary, and uterus. In addition to explaining normal physiological function, investigating DR may shed new light into pathologic processes that occur in these tissues and provide an exciting opportunity for novel therapeutic intervention.

Polymorphism, genetic effect and association with egg production traits of chicken matrix metalloproteinases 9 promoter

Matrix metalloproteinases (MMP) are key enzymes involved in cell and tissue remodeling during ovarian follicle development and ovulation. The control of MMP9 transcription in ovarian follicles occurs through a core promoter region (−2,400 to −1,700 bp). The aim of this study was to screen genetic variations in the core promoter region and examine MMP9 transcription regulation and reproduction performance. A single cytosine deletion/insertion polymorphism was found at −1954 C⁺/C⁻. Genetic association analysis indicated significant correlation between the deletion genotype (C⁻) with total egg numbers at 28 weeks (p = 0.031). Furthermore, luciferase-reporter assay showed the deletion genotype (C⁻) had significantly lower promoter activity than the insertion genotype (C⁺) in primary granulosa cells (p<0.01). Therefore, the identified polymorphism could be used for marker-assisted selection to improve chicken laying performance.

Reprolysin metalloproteases from Ixodes persulcatus, Rhipicephalus sanguineus and Rhipicephalus microplus ticks

Metalloproteases (MPs) have been considered essential for blood feeding and other physiological functions in several hematophagous animals, including ticks. We report the characterization of MP sequences of three important ticks from Asia, Africa and America: Ixodes persulcatus (Ip-MPs), Rhipicephalus sanguineus (Rs-MPs) and R. microplus (BrRm-MPs). Amino acid sequence identity between R. microplus and R. sanguineus MPs ranged from 76 to 100 %, and identities among I. persulcatus, I. ricinus and I. scapularis MP sequences ranged from 88 to 97 %. This high sequence identity and typical functional motifs show that all sequences are MPs. The presence of a zinc binding site, a Met-turn and cysteine rich domain at the C-terminal region indicates that these proteins belong to the reproplysin family of MPs. Differences in amino acid sequences of BrRm-MP1, BrRm-MP2, BrRm-MP4 and BrRm-MP5 (from Porto Alegre strain ticks) were 6, 2, 7 and 5 %, respectively, when compared with sequences deposited in GenBank for the same genes from other R. microplus isolates. Analyses of MPs predicted that they have various highly antigenic regions. Semi-quantitative RT-PCR analysis revealed the presence of transcripts in salivary glands of partially and fully fed female ticks. None of these transcripts were observed in males (except BrRm-MP4) and eggs. These enzymes may be functional components required during tick feeding to manipulate host defenses and support tick hematophagy.

Luteal activity of pregnant rats with hypo-and hyperthyroidism

Background

Luteal activity is dependent on the interaction of various growth factors, cytokines and hormones, including the thyroid hormones, being that hypo- and hyperthyroidism alter the gestational period and are also a cause of miscarriage and stillbirth. Because of that, we evaluated the proliferation, apoptosis and expression of angiogenic factors and COX-2 in the corpus luteum of hypo- and hyperthyroid pregnant rats.

Methods

Seventy-two adult female rats were equally distributed into three groups: hypothyroid, hyperthyroid and control. Hypo- and hyperthyroidism were induced by the daily administration of propylthiouracil and L-thyroxine, respectively. The administration began five days before becoming pregnant and the animals were sacrificed at days 10, 14, and 19 of gestation. We performed an immunohistochemical analysis to evaluate the expression of CDC-47, VEGF, Flk-1 (VEGF receptor) and COX-2. Apoptosis was evaluated by the TUNEL assay. We assessed the gene expression of VEGF, Flk-1, caspase 3, COX-2 and PGF2α receptor using real time RT-PCR. The data were analyzed by SNK test.

Results

Hypothyroidism reduced COX-2 expression on day 10 and 19 (P < 0.05), endothelial/pericyte and luteal cell proliferation on day 10 and 14 (p < 0.05), apoptotic cell numbers on day 19 (p < 0.05) and the expression of Flk-1 and VEGF on day 14 and 19, respectively (p < 0.05). Hyperthyroidism increased the expression of COX-2 on day 19 (P < 0.05) and the proliferative activity of endothelial/pericytes cells on day 14 (p <0.05), as well as the expression of VEGF and Flk-1 on day 19 (P < 0.05).

Conclusions

Hypothyroidism reduces the proliferation, apoptosis and expression of angiogenic factors and COX-2in the corpus luteum of pregnant rats, contrary to what is observed in hyperthyroid animals, being this effect dependent of the gestational period.

The extracellular matrix contributes to mechanotransduction in uterine fibroids

The role of the extracellular matrix (ECM) and mechanotransduction as an important signaling factor in the human uterus is just beginning to be appreciated. The ECM is not only the substance that surrounds cells, but ECM stiffness will either compress cells or stretch them resulting in signals converted into chemical changes within the cell, depending on the amount of collagen, cross-linking, and hydration, as well as other ECM components. In this review we present evidence that the stiffness of fibroid tissue has a direct effect on the growth of the tumor through the induction of fibrosis. Fibrosis has two characteristics: (1) resistance to apoptosis leading to the persistence of cells and (2) secretion of collagen and other components of the ECM such a proteoglycans by those cells leading to abundant disposition of highly cross-linked, disoriented, and often widely dispersed collagen fibrils. Fibrosis affects cell growth by mechanotransduction, the dynamic signaling system whereby mechanical forces initiate chemical signaling in cells. Data indicate that the structurally disordered and abnormally formed ECM of uterine fibroids contributes to fibroid formation and growth. An appreciation of the critical role of ECM stiffness to fibroid growth may lead to new strategies for treatment of this common disease.

Ovarian membrane-type matrix metalloproteinases: induction of MMP14 and MMP16 during the periovulatory period in the rat, macaque, and human

An intrafollicular increase in proteolytic activity drives ovulatory events. Surprisingly, the periovulatory expression profile of the membrane-type matrix metalloproteinases (MT-MMPs), unique proteases anchored to the cell surface, has not been extensively examined. Expression profiles of the MT-MMPs were investigated in ovarian tissue from well-characterized rat and macaque periovulatory models and naturally cycling women across the periovulatory period. Among the six known MT-MMPs, mRNA expression of Mmp14, Mmp16, and Mmp25 was increased after human chorionic gonadotropin (hCG) administration in rats. In human granulosa cells, mRNA expression of MMP14 and MMP16 increased following hCG treatment. In contrast, mRNA levels of MMP16 and MMP25 in human theca cells were unchanged before ovulation but declined by the postovulatory stage. In macaque granulosa cells, hCG increased mRNA for MMP16 but not MMP14. Immunoblotting showed that protein levels of MMP14 and MMP16 in rats increased, similar to their mRNA expression. In macaque granulosa cells, only the active form of the MMP14 protein increased after hCG, unlike its mRNA or the proprotein. By immunohistochemistry, both MMP14 and MMP16 localized to the different ovarian cell types in rats and humans. Treatment with hCG resulted in intense immunoreactivity of MMP14 and MMP16 proteins in the granulosa and theca cells. The present study shows that MMP14 and MMP16 are increased by hCG administration in the ovulating follicle, demonstrating that these MMPs are conserved among rats, macaques, and humans. These findings suggest that MT-MMPs could have an important role in promoting ovulation and remodeling of the ovulated follicle into the corpus luteum.

Prostaglandin E2 (EP) receptors mediate PGE2-specific events in ovulation and luteinization within primate ovarian follicles

Prostaglandin E2 (PGE2) is a key mediator of ovulation. All 4 PGE2 receptors (EP receptors) are expressed in the primate follicle, but the specific role of each EP receptor in ovulatory events is poorly understood. To examine the ovulatory events mediated via these EP receptors, preovulatory monkey follicles were injected with vehicle, the PG synthesis inhibitor indomethacin, or indomethacin plus PGE2. An ovulatory dose of human chorionic gonadotropin was administered; the injected ovary was collected 48 hours later and serially sectioned. Vehicle-injected follicles showed normal ovulatory events, including follicle rupture, absence of an oocyte, and thickening of the granulosa cell layer. Indomethacin-injected follicles did not rupture and contained oocytes surrounded by unexpanded cumulus; granulosa cell hypertrophy did not occur. Follicles injected with indomethacin plus PGE2 were similar to vehicle-injected ovaries, indicating that PGE2 restored the ovulatory changes inhibited by indomethacin. Additional follicles were injected with indomethacin plus an agonist for each EP receptor. EP1, EP2, and EP4 agonists each promoted aspects of follicle rupture, but no single EP agonist recapitulated normal follicle rupture as seen in follicles injected with either vehicle or indomethacin plus PGE2. Although EP4 agonist-injected follicles contained oocytes in unexpanded cumulus, the absence of oocytes in EP1 agonist- and EP2 agonist-injected follicles suggests that these EP receptors promote cumulus expansion. Surprisingly, the EP3 agonist did not stimulate any of these ovulatory changes, despite the high level of EP3 receptor expression in the monkey follicle. Therefore, agonists and antagonists selective for EP1 and EP2 receptors hold the most promise for control of ovulatory events in women.

Expression and regulation of MMP1, MMP3, and MMP9 in the chicken ovary in response to gonadotropins, sex hormones, and TGFB1

Matrix metalloproteinases (MMPs) are a specific class of proteolytic enzymes that play critical roles in follicular development and luteinization in mammals. However, the role of MMPs in avian ovary remains largely unknown. We found that three MMP genes (MMP1, MMP3, and MMP9) were significantly up-regulated in 23-wk-old (laying phase) chicken ovaries compared with 6-wk-old ovaries (prepubertal phase). In reproductively active chicken ovary, MMP1 expression (both mRNA and protein) remained low in prehierarchical and preovulatory follicles but increased in postovulatory follicles (POFs). Both MMP3 and MMP9 expression levels increased during follicular maturation. MMP3 reached maximal expression in the first largest follicle (F1), while MMP9 levels continued to rise in POF1 and POF2 after ovulation. Immunohistochemistry, Western blot analysis, and zymography experiments indicated that MMP1, MMP3, and MMP9 were synthesized and secreted by granulosa cells of different follicles in the chicken ovary. The mRNA expression of MMP1 and MMP3 in the granulosa cells was stimulated by follicle-stimulating hormone, luteinizing hormone, progesterone, and estrogen but not by transforming growth factor beta 1 (TGFB1). However, the mRNA of MMP9 was induced by TGFB1 but not follicle-stimulating hormone, luteinizing hormone, progesterone, or estrogen. Luciferase reporter and mutagenesis analysis indicated the AP1 and NFkappaB elements located in the promoter region from -1700 to -2400 bp were critical for both basal and TGFB1-induced MMP9 transcription. These data provide the first spatial-temporal expression analysis of MMP system in the chicken ovary.

The effect of equine metabolic syndrome on the ovarian follicular environment

Obesity in many species is associated with reduced fertility and increased risk of metabolic disorders and cardiovascular dysfunction in offspring. Equine metabolic syndrome (EMS) is associated with obesity and characterized by insulin resistance, decreased adiponectin, and elevated insulin, leptin, and pro-inflammatory cytokines. These alterations can potentially disrupt follicular development and impair fertility. We hypothesized that mares with EMS have an altered follicular environment when compared to their normal counterparts, affecting gene regulation for follicle and oocyte maturation. Samples were collected from light-horse mares (11 to 27 yr) in a clinical assisted reproductive program. Mares were screened based on phenotype. Insulin sensitivity was determined by using two proxies, the reciprocal of the square root of insulin (RISQI) and the modified insulin-to-glucose ratio (MIRG). Insulin resistant mares (RISQI < 0.32 and MIRG > 5.50) were allocated to the EMS group (n = 8), and the remaining mares were considered normal controls (CON, n = 12). Follicular fluid (FF) and granulosa cells (GC) from preovulatory follicles were aspirated 24 ± 2 h after administration of a GnRH analog (SucroMate, 0.9 to 1.4 mg, i.m.) and hCG (Chorion, 1500 to 2000 IU, i.v.). After an overnight fast, blood was collected on the morning of follicle aspiration to evaluate serum concentrations of insulin, leptin, adiponectin, and inflammatory cytokines. Expression of 32 genes related to metabolism, follicle maturation, and oocyte maturation were assessed in GC. Concentrations of insulin, leptin, adiponectin, and cytokines were highly correlated between serum and FF (P < 0.001). Insulin was lower (P < 0.001) in serum and FF of CON compared to EMS, but leptin and IL1β tended (P = 0.07 and P = 0.10, respectively) to be lower in FF of CON than EMS. Tumor necrosis factor-α in serum and FF was lower (P < 0.07 and P < 0.05, respectively) in CON than EMS. Conversely, adiponectin was higher (P < 0.05) in serum and FF in CON versus EMS. In GC from CON when compared to EMS, gene expression for epiregulin was elevated (P < 0.05) and tissue inhibitor of matrix metalloproteinase-2 tended to be lower (P = 0.09). Our findings demonstrate that the intrafollicular environment in the mare is influenced by metabolic disease, consistent with findings in other species. Influences on follicular development, oocyte maturation, and subsequent offspring by perturbations due to metabolic disease need further study.

Immunohistochemical expression of MMP-14 and MMP-2, and MMP-2 activity during human ovarian follicular development

BACKGROUND

The aim of this study was to investigate the presence of MMP-14 and MMP-2 during human ovarian follicular development using immunohistochemistry, and the activity of MMP-2 in follicular fluid using zymography.

METHODS

Ovarian tissue collected from the archives of the Department of Pathology was examined and medical records and histopathology were reviewed. Follicular fluids were collected at the IVF-department and analyzed using zymography.

RESULTS

MMP-14 and MMP-2 were increasingly found in the growing follicles and MMP-2 was highly expressed in the corpus luteum. Pro-MMP-2 was present in follicular fluid of IVF-patients.

CONCLUSIONS

The presence of MMP-14 and MMP-2 during human ovarian follicular development from the primordial follicle to the tertiary follicle and corpus luteum is confirmed, as was indicated by earlier animal studies following stimulation with gonadotrophins.

The evolution of embryo implantation

Embryo implantation varies widely in placental mammals. We review this variation in mammals with a special focus on two features: the depth of implantation and embryonic diapause. We discuss the two major types of implantation depth, superficial and interstitial, and map this character on a well-resolved molecular phylogenetic tree of placental mammals. We infer that relatively deep interstitial implantation has independently evolved at least eight times within placental mammals. Moreover, the superficial type of implantation represents the ancestral state for placental mammals. In addition, we review the genes involved in various phases of implantation, and suggest a future direction in investigating the molecular evolution of implantation-related genes.

Ovarian expression, localization, and function of tissue inhibitor of metalloproteinase 3 (TIMP3) during the periovulatory period of the human menstrual cycle

Ovulation involves reorganization of the extracellular matrix of the follicle. This study examines the expression, localization, and potential function of the tissue inhibitor of metalloproteinase 3 (TIMP3) during ovulation in women. The dominant follicle of the menstrual cycle was collected at specified times throughout the ovulatory process: pre-, early, late, and postovulatory. For quantitative studies, the follicle was bisected; granulosa and theca cells were separated and collected. For immunohistochemistry (IHC), the intact follicle was embedded and TIMP3 was localized. Additionally, granulosa cells were collected from women undergoing in vitro fertilization and treated with increasing concentrations of recombinant TIMP3, and cell viability was assessed. Real-time PCR for TIMP3 mRNA revealed an increase in TIMP3 mRNA expression in granulosa cells from the early to the late ovulatory stage. Thecal TIMP3 mRNA expression was constitutive across the periovulatory period. TIMP3 protein was localized by IHC to the granulosa and theca cell layers in pre-, early, and late ovulatory follicles as well as to the vascular bed. The staining was most intense in the granulosa and theca cells in the late ovulatory group. Treatment of human granulosa-lutein cells with exogenous recombinant TIMP3 for 24 h decreased cell viability by 60%. Using human follicles collected throughout the periovulatory period of the menstrual cycle, we have demonstrated that TIMP3 mRNA expression increases and that TIMP3 protein is in the appropriate cellular layers to regulate proteolytic remodeling as the follicle progresses toward ovulation. In addition, we have shown that elevated levels of TIMP3 lead to decreased cell viability.

Expression of matrix metalloproteinase-1 in round ligament and uterosacral ligament tissue from women with pelvic organ prolapse

To evaluate the matrix metalloproteinase-1 (MMP-1) expression in different parts of pelvic connective tissue in postmenopausal women with and without pelvic organ prolapse (POP). Ninety-one samples were obtained from only postmenopausal women (42 with POP and 49 non-POP subjects). All women were evaluated by pelvic organ prolapse quantitation. The POP group had stage 2 or more, and the controls had stage 1 or less. Round ligament (RL) and uterosacral ligament (USL) biopsies were obtained from women with POP and controls. Immunohistochemistry for MMP-1 was performed on formalin-fixed and paraffin-embedded sections. The two groups were matched for age, body mass index, parity and postmenopausal status. MedCalc Statistical Software Programme Version 12.0.5 was used for statistical analysis. Expression of MMP-1 were significantly higher in both RL and USL tissue from postmenopausal women with POP, compared with controls. MMP-1 immunoreactivities were identified in both RL and USL biopsies from all women with and without POP. The expression pattern of MMP-1 were similar in these ligaments and were significantly higher in POP group compared with control subjects. These changes indicate a possible relation between MMP-1 expression of RL and USL in women with and without POP.

Gonadal steroids regulate the expression of aggrecanases in human endometrial stromal cells in vitro

The human endometrium undergoes cyclic change during each menstrual cycle in response to gonadal steroids. Proteolysis of endometrial extracellular matrix (ECM) is necessary to prepare this dynamic tissue for pregnancy. Proteolytic enzymes such as matrix metalloproteinase (MMP) and closely related a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) have been assigned key roles in the highly regulated cyclic remodelling of the endometrial ECM. We have previously shown that ADAMTS-1 undergoes spatiotemporal changes in human endometrial stromal cells under the regulation of gonadal steroids. This suggests that other ADAMTS subtypes, known as aggrecanases, may contribute to the ECM remodelling events that occur in female physiological cycles and in preparation for pregnancy. To determine whether progesterone (P4), 17β-estradiol (E2), or dihydrotestosterone (DHT), alone or in combination, are capable of regulating ADAMTS-4, -5, -8 or -9 expression in human endometrial stromal cells in vitro. Real-time quantitative PCR and Western blot analysis were used to measure ADAMTSs mRNA and protein levels in primary cultures of human endometrial stromal cells (n = 12). P4, DHT but not E2 have regulatory effects on ADAMTS-8, -9 and -5 expression. Combined treatment with gonadal steroids did not show any synergistic or antagonistic effects. However, the synthetic steroid antagonists RU486 and hydroxyflutamide specifically inhibited the P4- or DHT-mediated regulatory effects on ADAMTS expression. These studies provide evidence that the regulation of aggrecanases by gonadal steroids in human endometrial stromal cells may play an important role during decidualization.

Activation of the PKC pathway stimulates ovarian cancer cell proliferation, migration, and expression of MMP7 and MMP10

Postmenopausal women are at a higher risk of ovarian cancer due, in part, to increased levels of gonadotropins such as luteinizing hormone (LH). Gonadotropins and other stimuli are capable of activating two pathways, PKA and PKC, that are altered in ovarian cancer. To determine the role of LH on ovarian cancer, we explored the effects of human chorionic gonadotropin (hCG), an LH mimic, and an activator of the PKC pathway, phorbol-12-myristate 13-acetate (PMA), on ovarian cancer cell-cycle kinetics and apoptosis in Ovcar3 cells. PMA treatment increased cells in the S phase of the cell cycle and initially increased apoptosis after 4 h before diminishing apoptosis after 8 h. Treatment of ovarian cancer cells with hCG had no effect on these parameters. The PKC pathway is known to differentially regulate matrix metalloproteinase (MMP) expression. Results showed that ovarian cancer cells treated with PMA increased MMP7 and MMP10 mRNA levels after 8 h of treatment, and expression remained high after 12 h before decreasing at 24 h. The mRNA expression of extracellular matrix metalloproteinase inducer (BSG), an activator of MMPs, was unaffected by PMA. Due to the role that MMPs play in migration, we investigated the effect of PMA activation of MMPs on ovarian cancer cell migration. The use of the MMP inhibitor GM6001 blocked the increased migratory effects of PMA on ovarian cancer cells. Together, these studies show that activating the PKC pathway causes significant changes in cell cycle kinetics and selective expression of MMPs that are involved in enhancing ovarian cancer cell proliferation and migration.

HOXA-11 mediated dysregulation of matrix remodeling during implantation window in women with endometriosis

PURPOSE

To investigate the Homeobox genes HOXA-10 and HOXA-11 mediated endometrial molecular defects during implantation window in endometriosis-associated infertility cases.

METHODS

Endometrial biopsies were obtained during implantation window from 31 infertile women with endometriosis (age < 35 years) and 26 age and BMI-matched infertile women without endometriosis were included in the study for comparison purposes. Endometrial expression of HOXA-10 and HOXA-11 genes, MMP-2, -9, α(v)β(3) integrin, leukemia inhibitory factor and surface characteristics including average roughness and topology were assessed.

RESULTS

A significantly lower expression of HOXA-10 and HOXA-11 were observed in endometriotic women compared to non-endometriotic controls. Further, a significantly higher endometrial expression of MMP-2 and -9 were observed in women with endometriosis when compared with controls. Interestingly, endometrial surface were observed to be grossly affected in terms of average roughness and topology in women with endometriosis compared to controls.

CONCLUSIONS

The findings suggest that aberrant expression of HOXA-10 and -11 genes adversely affects endometrial remodelling and expression of receptivity markers.

Estrus synchronization and ovarian hyper-stimulation treatments have negligible effects on cumulus oocyte complex gene expression whereas induction of ovulation causes major expression changes

The effects of exogenous hormones, used for estrus synchronization and ovarian hyper stimulation, on cumulus oocyte complexes (COCs) gene expression in sexually mature rats were determined using microarrays. Gene expression in COCs collected from GnRH (G(trt)), GnRH + eCG (G + E(trt)), and GnRH + eCG + hCG (G + E + H(trt)) treatments were compared to COCs from naturally cycling (NC) rats before the preovulatory luteninizing hormone surge. There was no significant difference in gene expression among NC, G(trt), and G + E(trt); however, over 2,600 genes were significantly different between NC and G + E + H(trt) (P < 0.05). Genes upregulated in G + E + H(trt) encode for: proteins that are involved in prostaglandin synthesis (Ptgs2, Pla2g4a, and Runx1) and cholesterol biosynthesis (Hmgcr, Sc4mol, and Dhcr24); receptors that allow cholesterol uptake (Ldlr and Scarb1), regulate progesterone synthesis (Star), and inactivate estrogen (Sult1e1); and downstream effectors of LH signal (Pgr, Cebpb, Creb3l1, Areg, Ereg, and Adamts1). Conversely, G + E + H(trt) downregulated genes encoding proteins involved in: DNA replication and cell cycle progression (Ccne2, Orc5l, Rad50, and Mcm6); reproductive developmental process; and granulosa cell expansion (Gdf9, Bmp15, Amh, Amhr2, Bmpr1b, Tgfb2, Foxl2, Pde3a, Esr2, Fshr, Ybx2, Ccnd2, Ccnb1ip1, and Zp3); maternal effect genes required for embryo development (Zar1, Npm2, Nlrp5, Dnmt1, H1foo, and Zfp57); amino acid degradation; and ketogenesis (Hmgcs2, and Cpt1b). These results from the rat show that hormones used for estrus synchronization (G(trt)) and ovarian hyper stimulation (G + E(trt)) had minimal effects on gene expression, whereas induction of ovulation (G + E + H(trt)) caused major changes in gene expression of rat COCs. This study provides comprehensive information about regulated genes during late follicle development and ovulation induction.

Changes in mouse uterine transcriptome in estrus and proestrus

Changes in the CD-1 mouse uterine transcriptome during proestrus and estrus were investigated to help elucidate mechanisms of uterine tissue remodeling during the estrus cycle and their regulation by estrogen and progesterone in preparation of the uterus for pregnancy. Mice were staged beginning at 6 weeks of age, and uterine horns were harvested after monitoring two estrus cycles. Microarray analysis of whole uterine horn RNA identified 2428 genes differentially expressed in estrus compared to proestrus, indicating there is extensive remodeling of mouse uterus during the estrus cycle, affecting ~10% of all protein-encoding genes. Many (~50%) of these genes showed the same differential expression in independent analyses of isolated uterine lumenal epithelial cells. Changes in gene expression associated with structural alterations of the uterus included remodeling of the extracellular matrix, changes in cell keratins and adhesion molecules, activation of mitosis and changes in major histocompatibility complex class II (MHCII) presentation, complement and coagulation cascades, and cytochrome P450 expression. Signaling pathways regulated during the estrus cycle, involving ligand-gated channels, Wnt and hedgehog signaling, and transcription factors with poorly understood roles in reproductive tissues, included several genes and gene networks that have been implicated in pathological states. Many of the molecular pathways and biological functions represented by the genes differentially expressed from proestrus to estrus are also altered during the human menstrual cycle, although not necessarily at the corresponding phases of the cycle. These findings establish a baseline for further studies in the mouse model to dissect mechanisms involved in uterine tissue response to endocrine disruptors and the development of reproductive tract diseases.

Luteinizing hormone stimulation of in vitro ovulation in brook trout (Salvelinus fontinalis) involves follicle contraction and activation of proteolytic genes

Luteinizing hormone (LH) is an essential hormone for the stimulation of the ovulatory process in vertebrates. However, little is known in fish regarding the different mechanisms induced by LH during ovulation that facilitate the rupture of the follicle wall and the subsequent expulsion of the mature oocyte. In this study, the effects of salmon LH (sLH) on in vitro ovulation were investigated in brook trout (Salvelinus fontinalis) isolated follicles. sLH significantly stimulated in vitro ovulation and contraction of brook trout preovulatory follicles. In order to investigate the possible involvement of proteolytic events in the ovulatory action of LH, the expression of genes known to have a crucial role in the degradation of follicle wall structure was examined. Our results show that sLH clearly stimulated the mRNA expression levels of matrix metalloproteinases (MMPs; including mmp2 and mmp19) and other enzymes with proteolytic action during ovulation, such as a disintegrin and metalloproteinase with thrombospondin-like motifs 1 (adamts1) and plasminogen (plg), in brook trout preovulatory follicles. In addition, the expression of mmp2, adamts1 and plg increased in brook trout follicles during the progression of LH-induced ovulation. Interestingly, the expression of tissue inhibitor of matrix metalloproteinase 2 (timp2), a known regulator of MMP2 activity, paralleled that of mmp2, suggesting the existence of a controlled mechanism of MMP2 action. Therefore, the known increase in proteolytic activity during ovulation in fish could be the result of the stimulation of the expression of proteolytic enzymes by LH in preovulatory follicles. We propose that LH may stimulate ovulation in brook trout follicles by stimulating proteolysis of the follicle wall and by stimulating follicle contraction.

Genetic variation in tissue inhibitors of metalloproteinases as a risk factor for idiopathic recurrent spontaneous abortion

OBJECTIVE

To investigate the potential association of tissue inhibitor of metalloproteinases (TIMP) 1, 2, 3, and 4 gene polymorphisms with idiopathic recurrent spontaneous abortion (IRSA).

DESIGN

Case-control and association study.

SETTING

Departments of gynecology and obstetrics and university-based research laboratory.

PATIENT(S)

A total of 149 couples with a history of three or more idiopathic spontaneous pregnancy losses and 149 fertile men and 149 fertile women with at least two live births and no history of pregnancy pathologies.

INTERVENTION(S)

Polymerase chain reaction and restriction-fragment-length polymorphism methods.

MAIN OUTCOME MEASURE(S)

Detection of TIMP-1 -372 C/T, TIMP-2 -303 C/T, TIMP-3 -915 A/G, TIMP-3 -1296 C/T, and TIMP-4 -3'-UTR C/T genotypes and allele frequencies.

RESULT(S)

There were no statistically significant differences in the distribution of any genotype and allele frequencies or any genetic model between IRSA patients and controls. Additionally, no significant associations occurred between combinations of TIMP polymorphisms and the risk of IRSA.

CONCLUSION(S)

We found no evidence for the association of TIMP-1, -2, -3, and -4 with IRSA in a Slovenian population.

Membrane receptor cross talk in steroidogenesis: recent insights and clinical implications

Steroid production by all three major steroidogenic tissues, the adrenals, testes, and ovaries, is critical for survival and reproduction of all animals. As such, the pathways that regulate steroidogenesis are conserved between these tissues, from the steroidogenic enzymes and cofactors that synthesize steroids, to the intracellular signaling molecules and Gαs-coupled receptors that mediate the activity of these enzymes. Recent work has revealed another important conserved pathway in steroidogenesis: crosstalk between membrane G protein-coupled receptors and membrane receptor tyrosine kinases. Luteinizing hormone (LH) or adrencorticotropic hormone (ACTH) binding to their cognate Gαs-coupled membrane receptors in the gonads and adrenals, respectively, leads to cAMP-induced trans-activation of the epidermal growth factor (EGF) receptor, followed by activation of Akt and Erk signaling. These kinase signals then activate Steroidogenic Acute Regulatory (StAR) protein, which promotes steroid production. Inhibition of this pathway abrogates both LH- and ACTH-induced steroidogenesis. Interestingly, LH-induced transactivation of the EGF receptor in the ovary uniquely requires matrix metalloproteinase-mediated release of EGF receptor ligands, and inhibition of these proteases blocks LH-induced steroidogenesis. Given this unique need for matrix metalloproteinases in ovarian steroidogenesis, MMP inhibition may prove to be useful when treating diseases of excess ovarian steroid production, such as polycystic ovary syndrome.

Proteomic analysis of human follicular fluid: a new perspective towards understanding folliculogenesis

Human follicular fluid is a complex body fluid that constitutes the microenvironment of developing follicles in the ovary. Follicular fluid contains a number of proteins that modulate oocyte maturation and ovulation. Information about the protein constituents of follicular fluid may provide a better understanding of ovarian physiology in addition to opening new avenues for investigating ovarian disorders. However, the composition of follicular fluid proteome remains poorly defined. In this study, we carried out SDS-PAGE, OFFGEL and SCX-based separation followed by LC-MS/MS analysis to characterize the proteome of human follicular fluid. We report high confidence identification of 480 proteins, of which 320 have not been described previously in the follicular fluid. The identified proteins belong to diverse functional categories including growth factor and hormones, receptor signaling, enzyme catalysis, defense/immunity and complement activity. Our dataset should serve as a resource for future studies aimed at developing biomarkers for monitoring oocyte and embryo quality, pregnancy outcomes and ovarian disorders.

BIOLOGICAL SIGNIFICANCE

Proteome analysis of human follicular fluid by multi-pronged approach of protein peptide fractionation revealed 480 proteins with high confidence. The identified protein may facilitate the understanding of folliculogenesis. This protein dataset should serve as a useful resource for development of biomarkers for oocyte quality, in vitro fertilization techniques and female infertility.

Human chorionic gonadotropin (hCG) modulation of TIMP1 secretion by human endometrial stromal cells facilitates extravillous trophoblast invasion in vitro

STUDY QUESTION

Are secreted extracellular matrix (ECM) remodelling elements, relevant to embryo implantation and placentation, modified by hCG in endometrial stromal cells (ESCs)?

SUMMARY ANSWER

hCG decreases tissue inhibitor of metalloproteinase 1 (TIMP-1) secretion in ESCs, thereby facilitating extravillous trophoblast invasion in vitro.

WHAT IS KNOWN ALREADY

Successful embryo implantation and placentation depend on the appropriate invasion of the trophoblast into the maternal endometrial stroma. hCG is one of the earliest embryo-derived secreted signals in the endometrium which abundantly expresses hCG receptors. However, there is little data concerning the effects of hCG on endometrial ECM remodelling with respect to embryo implantation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study was conducted in an academic research laboratory within a tertiary-care hospital. Samples were collected from 36 women undergoing benign gynaecological surgery during the mid-secretory phase. ESCs were isolated and stimulated with hCG (10 UI/ml) or vehicle. Conditioned media (CM) were analysed to determine changes in the secreted profile of nine matrix metalloproteinases (MMPs) and three tissue-specific inhibitors of MMPs (TIMPs) using an ELISA array. Data were confirmed by gelatine zymography, western blot and ELISA. The HTR8/SVneo cell line served as a model for trophoblast cells. The invasive potential of trophoblast cells was assessed using Transwell invasion assays under CM or co-culture conditions with ECS and the role of regulated molecules was examined by using immunoprecipitation in CM prior to the assessment of invasive potential.

MAIN RESULTS AND THE ROLE OF CHANCE

MMP-2 levels increased 30%, whereas TIMP-1 levels decreased 20% in CM from ESCs stimulated with hCG (P < 0.05). Gelatine zymography confirmed an increase in MMP-2 activity (P < 0.05). ELISA and western blotting also confirmed the reduction in TIMP-1 upon hCG treatment (P < 0.05). Invasion assays revealed a ∼50% increase in invading HTR8/SVneo cells in chambers with hCG-stimulated ESCs compared with the control (P < 0.05). Immunodepletion of TIMP-1 from control ESC-CM partially resembled the effect of CM from hCG-stimulated ESCs in the trophoblast invasion assays.

LIMITATIONS, REASONS FOR CAUTION

The assays were performed in vitro and ESCs were not decidualized, therefore they reflected the very early stages of embryo implantation or the advanced stages when decidualization fails.

WIDER IMPLICATIONS OF THE FINDINGS

Our data suggest that hCG induces endometrial stromal extracellular remodelling by modulating secreted MMP-2 and TIMP-1. This regulation may be physiologically relevant because it increases the invasive potential of trophoblast-derived cells. At present, few data exist concerning the implications of hCG and endometrial ECM remodelling in embryo implantation. Hence, our results should be confirmed by further in vivo studies.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by FONDECYT 11100443, PBCT-PSD51 (IDIMI) and FONDAP 15010006. None of the authors have any conflicts of interest to declare.

The microtubule stabilizer patupilone counteracts ionizing radiation-induced matrix metalloproteinase activity and tumor cell invasion

Background

Ionizing radiation (IR) in combination with microtubule stabilizing agents (MSA) is a promising combined treatment modality. Supra-additive treatment responses might result from direct tumor cell killing and cooperative indirect, tumor cell-mediated effects on the tumor microenvironment. Here we investigated deregulation of matrix metalloproteinase (MMP) activity, as an important component of the tumor microenvironment, by the combined treatment modality of IR with the clinically relevant MSA patupilone.

Methods

Expression, secretion and activity of MMPs and related tissue inhibitors of metalloproteinases (TIMPs) were determined in cell extracts and conditioned media derived from human fibrosarcoma HT1080 and human glioblastoma U251 tumor cells in response to treatment with IR and the MSA patupilone. Treatment-dependent changes of the invasive capacities of these tumor cell lines were analysed using a Transwell invasion assay. Control experiments were performed using TIMP-directed siRNA and TIMP-directed inhibitory antibodies.

Results

Enzymatic activity of secreted MMPs was determined after treatment with patupilone and irradiation in the human fibrosarcoma HT1080 and the human glioblastoma U251 tumor cell line. IR enhanced the activity of secreted MMPs up to 2-fold and cellular pretreatment with low dose patupilone (0.05-0.2 nM) counteracted specifically the IR-induced MMP activity. The cell invasive capacity of HT1080 and U251 cells was increased after irradiation with 2 Gy by 30% and 50%, respectively, and patupilone treatment completely abrogated IR-induced cell invasion. Patupilone did not alter the level of MMP expression, but interestingly, the protein level of secreted TIMP-1 and TIMP-2 was lower after combined treatment than after irradiation treatment alone. Furthermore, siRNA depletion of TIMP-1 or TIMP-2 prevented IR-mediated induction of MMP activity and cell invasion.

Conclusions

These results indicate that patupilone counteracts an IR-induced MMP activation process by the reduction of secreted TIMP-1 and TIMP-2 proteins, which are required for activation of MMPs. Since IR-induced MMP activity could contribute to tumor progression, treatment combination of IR with patupilone might be of great clinical benefit for tumor therapy.

The plasminogen activator system in the ovine placentome during late gestation and stage-two of parturition

The process of placental separation is not completely understood. In domestic animals, especially cattle, it is important that expulsion of the fetal membranes takes place in a timely manner in order to achieve maximal reproductive efficiency. The activity of the matrix-metalloprotease (MMP) family of proteases is known to be reduced in placentomes from cases of retained placenta. Members of the MMP family are known to be activated by the plasminogen activator (PA) family of proteases. We hypothesized that the expression and activity of the PA family increase in the cotyledon and/or caruncle as parturition approaches, with maximal expression and activity at parturition. To test this hypothesis, we performed reverse-transcriptase quantitative PCR and plasminogen-casein zymography to detect the presence and activity of PA family members in the placentome leading up to and during parturition in spontaneous and dexamethasone-induced parturient ewes. The results from our experiments indicated that serine proteases inhibitor E1 (SERPINE1) mRNA abundance in the cotyledon was different between treatment groups (P = 0.0002). In the caruncle, gene expression for plasminogen activator urokinase-type (PLAU) was different (P = 0.0154), and there was a strong trend for differences in SERPINE1 expression (P = 0.0565). These results demonstrate that expression of the PA system in the placentome changes from late pregnancy to parturition, and the presence or activity of these enzymes may occur after fetal expulsion.

Distinct spatiotemporal expression of serine proteases Prss23 and Prss35 in periimplantation mouse uterus and dispensable function of Prss35 in fertility

PRSS23 and PRSS35 are homologous proteases originally identified in mouse ovaries. In the periimplantation mouse uterus, Prss23 was highly expressed in the preimplantation gestation day 3.5 (D3.5) uterine luminal epithelium (LE). It disappeared from the postimplantation LE and reappeared in the stromal compartment next to the myometrium on D6.5. It was undetectable in the embryo from D4.5 to D6.5 but highly expressed in the embryo on D7.5. Prss35 became detectable in the uterine stromal compartment surrounding the embryo on D4.5 and shifted towards the mesometrial side of the stromal compartment next to the embryo from D5.5 to D7.5. In the ovariectomized uterus, Prss23 was moderately and Prss35 was dramatically downregulated by progesterone and 17β-estradiol. Based on the expression of Prss35 in granulosa cells and corpus luteum of the ovary and the early pregnant uterus, we hypothesized that PRSS35 might play a role in female reproduction, especially in oocyte development, ovulation, implantation, and decidualization. This hypothesis was tested in Prss35((-/-)) mice, which proved otherwise. Between wild type (WT) and Prss35((-/-)) mice, superovulation of immature females produced comparable numbers of cumulus-oocyte complexes; there were comparable numbers of implantation sites detected on D4.5 and D7.5; there were no obvious differences in the expression of implantation and decidualization marker genes in D4.5 or D7.5 uteri. Comparable mRNA expression levels of a few known protease-related genes in the WT and Prss35((-/-)) D4.5 uteri indicated no compensatory upregulation. Comparable litter sizes from WT × WT and Prss35((-/-))× Prss35((-/-)) crosses suggested that Prss35 gene was unessential for fertility and embryo development. Prss35 gene has been linked to cleft lip/palate in humans. However, no obvious such defects were observed in Prss35((-/-)) mice. This study demonstrates the distinct expression of Prss23 and Prss35 in the periimplantation uterus and the dispensable role of Prss35 in fertility and embryo development.