Expression of transforming growth factor-beta 1 messenger ribonucleic acid and the modulation of deoxyribonucleic acid synthesis by transforming growth factor-beta 1 in human endometrial cells

The Expression of TGF-β1, SMAD3, ILK and miRNA-21 in the Ectopic and Eutopic Endometrium of Women with Endometriosis

The molecular pathogenesis of endometriosis has been associated with pathological alterations of protein expression via disturbances in homeostatic genes, miRNA expression profiles, and signaling pathways that play an essential role in the epithelial-mesenchymal transition (EMT) process. TGF-β1 has been hypothesized to play a key role in the development and progression of endometriosis, but the activation of a specific mechanism via the TGF-β-SMAD-ILK axis in the formation of endometriotic lesions is poorly understood. The aim of this study was to assess the expression of EMT markers (TGF-β1, SMAD3, ILK) and miR-21 in ectopic endometrium (ECE), in its eutopic (EUE) counterpart, and in the endometrium of healthy women. The expression level of the tested genes and miRNA was also evaluated in peripheral blood mononuclear cells (PBMC) in women with and without endometriosis. Fifty-four patients (n = 54; with endometriosis, n = 29, and without endometriosis, n = 25) were enrolled in the study. The expression levels (RQ) of the studied genes and miRNA were evaluated using qPCR. Endometriosis patients manifested higher TGF-β1, SMAD3, and ILK expression levels in the eutopic endometrium and a decreased expression level in the ectopic lesions in relation to control tissue. Compared to the endometrium of healthy participants, miR-21 expression levels did not change in the eutopic endometrium of women with endometriosis, but the RQ was higher in their endometrial implants. In PBMC, negative correlations were found between the expression level of miR-21 and the studied genes, with the strongest statistically significant correlation observed between miR-21 and TGF-β1. Our results suggest the loss of the endometrial epithelial phenotype defined by the differential expression of the TGF-β1, SMAD3 and ILK genes in the eutopic and ectopic endometrium. We concluded that the TGF-β1-SMAD3-ILK signaling pathway, probably via a mechanism related to the EMT, may be important in the pathogenesis of endometriosis. We also identified miR-21 as a possible inhibitor of this TGF-β1-SMAD3-ILK axis.

Association between TGF-β1-509C/T polymorphism and endometriosis: a systematic review and meta-analysis

OBJECTIVE

To evaluate the association between the transforming growth factor β1 gene-509C/T (TGF-β1-509C/T) polymorphism and the risk of endometriosis.

STUDY DESIGN

Relevant studies published before October 2011 were identified by searching PubMed and Embase. Studies were selected using prior defined criteria. The strength of the relationship between the TGF-β1-509C/T polymorphism and endometriosis risk was assessed by Odds Ratios (ORs). Fixed- or random-effects model was calculated according to study heterogeneity. Stratification analysis and sensitivity analysis were also conducted. Possible publication bias was tested by funnel plots and Egger's test.

RESULTS

Of 49 potentially relevant studies, six case-control studies were identified in this meta-analysis. The integrated result showed that the TGF-β1-509C/T polymorphism was not associated with the endometriosis risk for the allele contrast (T vs. C: OR=1.57, 95%CI=0.88-2.79), the additive genetic model (T/T vs. C/C: OR=2.96, 95%CI=0.97-9.10), the dominant genetic model (T/T+T/C vs. C/C: OR=1.80, 95%CI=0.80-4.07) and the recessive genetic model (T/T vs. C/C+T/C: OR=1.91, 95%CI=0.89-4.12). In the stratified analysis by ethnicity, genotyping method and source of control, no significantly association was found. Publication bias was not detected in the included studies.

CONCLUSIONS

Meta-analyses of the available data showed that the association between TGF-β1-509C/T polymorphism and susceptibility of endometriosis was not significant. More studies are needed to elucidate its role in endometriosis.

Is endometrial polyp formation associated with increased expression of vascular endothelial growth factor and transforming growth factor-beta1?

OBJECTIVE

Endometrial polyp is a common cause of abnormal uterine bleeding, but the etiology and pathogenesis remain unclear. Vascular endothelial growth factor (VEGF) is angiogenic, related to thick walled vessels and transforming growth factor-beta1 (TGF-β1) is related to fibrotic tissue, which are characteristics of endometrial polyps. The primary objective of this study was to find out if endometrial polyp formation is associated with increased expression of VEGF or TGF-β1, or both. A secondary objective is to determine if the changes are related to steroid receptor expression.

STUDY DESIGN

This prospective study compared VEGF and TGF-β1 expression of endometrial polyps and adjacent endometrial tissue in 70 premenopausal women. The comparison of results was separately made for endometrium specimens obtained in the proliferative and secretory phases. The results were correlated with the steroid receptors (estrogen receptor and progesterone receptor) expression.

RESULTS

The score of VEGF in glandular cells of endometrial polyps was significantly higher than the score in adjacent endometrium, both in the proliferative phase (P<0.001) and the secretory phase (P=0.03); the score of VEGF in stromal cells of endometrial polyps was significantly higher than the score in adjacent endometrium only in proliferative phase (P=0.006). The score of TGF-β1 in glandular cells of endometrial polyps was significantly higher than the score in adjacent endometrium in proliferative phase (P=0.02); whereas the score of TGF-β1 in stromal cells of endometrial polyps was significantly higher than the score in adjacent endometrium, both in the proliferative phase (P=0.006) and the secretory phase (P=0.008). There was a significant correlation between the expression of steroid receptors and VEGF and TGF-β1 (Spearman's correlation P<0.001 and P<0.05, respectively).

CONCLUSIONS

There was increased expression of TGF-β1 and VEGF in polyps compared to adjacent normal endometrial tissue. It suggested that these cytokines might play a role in endometrial polyp formation. In addition, there was a significant correlation between steroid receptor expression and VEGF and TGF-β1 expression.

Matrix metalloproteinases and their tissue inhibitors in endometrial remodelling and menstruation

The architecture of the human endometrium is extensively remodelled during the course of each normal menstrual cycle, unlike most other tissues and organs which undergo very little change during adult life. During menstruation, when loss of most of the functionalis layer occurs, there is concomitant epithelial regrowth; repair of the luminal surface is complete almost as bleeding ceases. During the proliferative phase of the cycle and under the influence of rising oestrogen levels, the stromal cells, glands and blood vessels undergo rapid proliferation which results in tissue thickening. Following ovulation (around day 14 of the idealized 28-day cycle), the secretory phase of the cycle is characterized by increasing tortuosity of the spiral arterioles and glands and increased glandular secretory activity. After about day 22, decidualization of many of the stromal fibroblasts also occurs, the resultant decidual cells having many characteristics typical of epithelial cells. Periods of tissue oedema are apparent both in mid-proliferative (days 8–11) and mid-secretory (days 20–23) endometrium. Late in the cycle, there is regression of the tissue as menstruation is initiated.

Analysis of the transforming growth factor beta1 gene -509 C/T polymorphism in patients with advanced-stage endometriosis

OBJECTIVE

To investigate whether the transforming growth factor beta (TGF-beta) gene -509 C/T polymorphism is associated with susceptibility to advanced-stage endometriosis.

DESIGN

Case-control study.

SETTING

University department of obstetrics and gynecology.

PATIENT(S)

Women with advanced-stage endometriosis (n = 485) and without endometriosis (n = 352).

INTERVENTION(S)

Genotyping by real-time polymerase chain reaction using a Taqman assay.

MAIN OUTCOME MEASURE(S)

Genotype distribution and allele frequency of the -509 C/T polymorphism in the TGF-beta1 gene.

RESULT(S)

The genotype distribution of the TGF-beta1 gene -509 C/T polymorphism in the endometriosis group was not different from that of the control group (CC/CT/TT rates were 29.3%/48.2%/22.5% and 27.3%/50.3%/22.4% for the endometriosis and control groups, respectively). Further subgroup analyses according to the stage of endometriosis or bilaterality of ovarian endometrioma also revealed no significant differences in the genotype distribution between each of the subgroups and the control group.

CONCLUSION(S)

These results suggest that the TGF-beta1 -509 C/T polymorphism may not be associated with an increased risk for advanced-stage endometriosis.

Opposite regulation of transforming growth factors-beta2 and -beta3 expression in the human endometrium

TGF-betas have been reported to mediate the repression by progesterone of several matrix metalloproteinases in the human endometrium, thereby preventing menstrual breakdown. Because of conflicting reports on the expression profiles, source, and regulation of the TGF-beta system in this tissue, we investigated by real-time RT-PCR and ELISA the expression of the three TGF-betas (total and mature forms) and their two receptors throughout the menstrual cycle, and their regulation by ovarian steroids in cultured explants including their microdissected epithelial and stromal compartments. Regulation by cAMP and MAPK was further investigated. This comprehensive study on a large collection of endometrial samples evidenced a differential regulation of TGF-beta isoforms expression, both in vivo and in explant culture. In vivo, TGF-beta2 increased by about 5-fold at the mid-late secretory phase then declined after menstruation; TGF-beta3 increased at menstruation and remained high during the proliferative phase; TGF-beta1 was maximal at menstruation. In explants cultured without ovarian steroids both TGF-beta2 and -beta3 were preferentially expressed in the stroma. Ovarian steroids strongly repressed both TGF-beta2 and -beta3 in stroma but only TGF-beta2 in glands. cAMP prevented inhibition by ovarian steroids of TGF-beta2 but not -beta3. In presence of ovarian steroids, MAPK inhibitors (p38 and ERK pathways) stimulated TGF-beta3 but inhibited TGF-beta2 expression. In conclusion, TGF-beta2 and -beta3 are differentially expressed during the menstrual cycle and regulated by progesterone in epithelial vs stromal cells. The opposite regulation of TGF-beta2 and -beta3 by cAMP and MAPK could account for their distinct expression in vivo.

Inhibition of human neutrophil degranulation by transforming growth factor-beta1

Neutrophils enter tissues including the uterus and are found in the endometrium in increased numbers prior to menses. In this environment, they are exposed to transforming growth factor (TGF)-beta1 produced by endometrial stromal and epithelial cells. We observed that incubation of neutrophils in vitro with TGF-beta1 at 1 pg/ml significantly reduced their secretion of lactoferrin in response to lipopolysaccharide (LPS). This effect was achieved with as little as 15 min of pretreatment with TGF-beta1. Inhibition of lactoferrin release by TGF-beta1 was observed irrespective of whether neutrophils were stimulated by ligands for Toll-like receptor (TLR)-2, TLR-4 or FPR, the G protein-coupled receptor for formylated peptides. Inhibition by TGF-beta1 was negated by SB-431542, a small molecule inhibitor that specifically blocks the kinase activity of the type I TGF-beta receptor (ALK5) In contrast to lactoferrin release, another important neutrophil function, interleukin (IL)-8 driven chemotaxis, was not affected by TGF-beta1 at 1 pg/ml or 100 pg/ml. We conclude that in tissues of the female reproductive tract, TGF-beta1 inhibition of neutrophil degranulation may prevent these cells from initiating an inflammatory response or releasing degradative enzymes that could potentially damage the oocyte or fetus.

Endocrine regulation of menstruation

In women, endometrial morphology and function undergo characteristic changes every menstrual cycle. These changes are crucial for perpetuation of the species and are orchestrated to prepare the endometrium for implantation of a conceptus. In the absence of pregnancy, the human endometrium is sloughed off at menstruation over a period of a few days. Tissue repair, growth, angiogenesis, differentiation, and receptivity ensue to prepare the endometrium for implantation in the next cycle. Ovarian sex steroids through interaction with different cognate nuclear receptors regulate the expression of a cascade of local factors within the endometrium that act in an autocrine/paracrine and even intracrine manner. Such interactions initiate complex events within the endometrium that are crucial for implantation and, in the absence thereof, normal menstruation. A clearer understanding of regulation of normal endometrial function will provide an insight into causes of menstrual dysfunction such as menorrhagia (heavy menstrual bleeding) and dysmenorrhea (painful periods). The molecular pathways that precipitate these pathologies remain largely undefined. Future research efforts to provide greater insight into these pathways will lead to the development of novel drugs that would target identified aberrations in expression and/or of local uterine factors that are crucial for normal endometrial function.

Regulation of proliferation, motility, and contractivity of cultured human endometrial stromal cells by transforming growth factor-β isoforms

OBJECTIVE

To evaluate the involvement of transforming growth factor (TGF)-beta isoforms (TGF-beta1, TGF-beta2, and TGF-beta3) on endometrial tissue remodeling during the perimenstrual period.

DESIGN

The effects of TGF-beta isoforms on the cell proliferation, motility, and contractivity of cultured human endometrial stromal cells (ESCs) were investigated.

SETTING

Research laboratory at a medical school.

PATIENT(S)

Nine endometrial specimens in the late secretory phase were used.

INTERVENTION(S)

Endometrial stromal cells were incubated with recombinant human recombinant TGF-beta1, TGF-beta2, and TGF-beta3.

MAIN OUTCOME MEASURE(S)

The cell proliferation, motility, and contractivity of ESCs were accessed by a modified methylthiazoletetrazolium assay, in vitro wound repair assay, transwell invasion assay, and collagen gel contraction assay.

RESULT(S)

All three isoforms of TGF-beta significantly inhibited the cell proliferation of ESCs in a dose-dependent manner. In vitro wound repair assay and transwell invasion assay demonstrated that the TGF-beta isoforms significantly inhibited the motility of ESCs. However, the TGF-beta isoforms were shown to have a clear effect on the collagen gel contractivity of ESCs.

CONCLUSION(S)

These results suggest that TGF-beta isoforms may promote endometrial tissue repair through the inhibition of the proliferation, expansion, and migration of ESCs, and through the stimulation of the contraction of the collagen gel matrix by these cells. Transforming growth factor-beta may be involved in the protection of the endometrium from extensive fibrosis and scarring by regulating ESC function during the perimenstrual period.

Augmented cell survival in eutopic endometrium from women with endometriosis: expression of c-myc, TGF-beta1 and bax genes

BACKGROUND

Endometriosis is a common gynaecological disorder characterized by the presence of endometrial tissue outside of the uterus. The fragments in normal menstruation are composed of necrotic and living cells, which do not survive in ectopic locations because of programmed cell death. The aim of this study was to evaluate if the balance between cell proliferation and apoptosis is changed in eutopic endometrium from women with endometriosis throughout the menstrual cycle by studying bax (pro-apoptotic), c-myc (regulator of cell cycle) and TGF-beta1 (involved in cell differentiation) genes.

METHODS

Eutopic endometrium was obtained from: 30 women with endometriosis (32.8 +/- 5 years) and 34 fertile eumenorrheic women (36 +/- 5.3 years). We analyzed apoptosis (TUNEL: DNA fragmentation); cell proliferation (immunohistochemistry (IHC) for Ki67); c-myc, bax and TGF-beta1 mRNA abundance (RT-PCR) and TGF-beta1 protein (IHC) in endometrial explants.

RESULTS

Cell proliferation strongly decreased from proliferative to late secretory phases in glands, but not in stroma, in both endometria. Positive staining in glands and stroma from proliferative endometrium with endometriosis was 1.9- and 2.2-fold higher than control endometrium, respectively (p < 0.05). Abundance of c-myc mRNA was 65% higher in proliferative endometrium from endometriosis than normal tissue (p < 0.05). TGF-beta1 (mRNA and protein) augmented during mid secretory phase in normal endometrium, effect not observed in endometrium with endometriosis. In normal endometrium, the percentage of apoptotic epithelial and stromal cells increased more than 30-fold during late secretory phase. In contrast, in endometrium from endometriosis, not only this increase was not observed, besides bax mRNA decreased 63% versus normal endometrium (p < 0.05). At once, in early secretory phase, apoptotic stromal cells increased 10-fold with a concomitant augment of bax mRNA abundance (42%) in endometria from endometriosis (p < 0.05).

CONCLUSION

An altered expression of c-myc, TGF-beta1 and bax was observed in eutopic endometrium from endometriosis, suggesting its participation in the regulation of cell survival in this disease. The augmented cell viability in eutopic endometrium from these patients as a consequence of a reduction in cell death by apoptosis, and also an increase in cell proliferation indicates that this condition may facilitate the invasive feature of the endometrium.

Differences in gene expression in the proliferative human endometrium

OBJECTIVE

To use microdissection and DNA microarray technology to demonstrate differences in gene expression between epithelial and stromal areas in the proliferative human endometrium.

DESIGN

Pilot study.

SETTING

University hospital.

PATIENT(S)

Patients with normal menstrual cycles and at least one previous intrauterine pregnancy.

INTERVENTION(S)

Uterine endometrial biopsy.

MAIN OUTCOME MEASURE(S)

Gene expression.

RESULT(S)

From a total of 1,200 genes, 14 were strongly expressed in epithelial areas and 12 were strongly expressed in stromal areas. Among the genes strongly expressed in the stroma, expressions of decorin and discoidin domain receptor were confirmed by real-time polymerase chain reaction. Decorin was localized in the stromal areas by immunohistochemical staining. To confirm the effects of estrogen on gene expression, stromal cells were cultured. When E(2) was added to the culture media, expression of decorin mRNA was increased.

CONCLUSION(S)

The data demonstrated in this study help to understand the physiology of human endometrium. Decorin was strongly expressed in the stromal areas and was regulated by estrogen, and therefore it may be involved in restoration of the endometrium.

Heparin-binding epidermal growth factor and its receptors mediate decidualization and potentiate survival of human endometrial stromal cells

Heparin-binding epidermal growth factor (HB-EGF) has pleiotropic biological functions in many tissues, including those of the female reproductive tract. It facilitates embryo development and mediates implantation and is thought to have a function in endometrial receptivity and maturation. The mature HB-EGF molecule manifests its activity as either a soluble factor (sol-HB-EGF) or a transmembrane precursor (tm-HB-EGF) and can bind two receptors, EGFR and ErbB4/HER4. In this study, we identify factors that modulate expression of HB-EGF, EGFR, and ErbB4 in endometrial stromal cells in vitro. We demonstrate that levels of sol- and tm-HB-EGF, EGFR, and ErbB4 are increased by cAMP, a potent inducer of decidualization of the endometrial stroma. We also show that production of sol- and tm-HB-EGF is differentially modulated by TNF alpha and TGF beta. Our data suggest that HB-EGF has a function in endometrial maturation in mediating decidualization and attenuating TNF alpha- and TGF beta-induced apoptosis of endometrial stromal cells.

Discoordinate regulation of expression of matrix metalloproteinases and tissue inhibitor of metalloproteinases-3 in bovine endometrial stromal cells on type-I collagen gel

To clarify the mechanism of extracellular matrix (ECM) remodeling in bovine endometrium, we investigated the regulation of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-3 (TIMP-3) in bovine endometrial stromal cells (BESCs) on type-I collagen gel. When BESCs were seeded onto the center of collagen gel placed in culture dishes, the cells proliferated and formed multiple cell layers after 2 weeks. Under this culture condition, the production of progelatinase B/promatrix metalloproteinase (proMMP)-9 was augmented, which was not occurred with monolayered BESCs on plastic dishes. The mRNA expression of progelatinase A/proMMP-2 was not changed, but proMMP-2 activation was augmented. Furthermore, the level of prostromelysin-1/proMMP-3 mRNA was decreased, whereas the gene expression of TIMP-3 tended to increase in BESCs cultured on collagen gel. When BESCs cultured on collagen gel were treated with transforming growth factor-beta1 (TGF-beta1), the levels of proMMP-9 in the medium and TIMP-3 mRNA were augmented, but the mRNA expression of proMMP-3 was further suppressed. However, the expression and activation of proMMP-2 were not changed by TGF-beta1 in BESCs cultured on either plastic or collagen-gel dishes. These results suggest that the expression of MMPs-2, 3 and 9 and TIMP-3 is likely to be discoordinately regulated due to interaction with collagen and/or TGF-beta1 in bovine endometrium, and thereby different sets of MMPs may be associated with ECM remodeling during implantation and placentation in vivo.

Paracrine/autocrine control of female reproduction

Neuropeptides, growth factors and cytokines are expressed in reproductive organs and tissues, where they interact with afferent endocrine messages to modulate cell proliferation and differentiation, local hormone secretion and vascular function. These events regulate complex processes such as gonadotropin pulsatility, ovulation, implantation and parturition. During reproductive life, a number of neuropeptides produced within the hypothalamus play a modulatory role in the control of gonadotropin-releasing hormone (GnRH) release, hence characterizing a hypothalamic paracrine system. The pituitary gland is a source and target of inhibin-related proteins, and these typical 'gonadal' products, once secreted by the pituitary cells, acquire the function of paracrine modulators of follicle-stimulating hormone (FSH) secretion. In the ovary, the effect of gonadotropins is locally modulated by growth factors acting in an autocrine/paracrine manner, although their precise role in folliculogenesis remains uncertain. Numerous local factors are involved in the control of endometrial growth, differentiation, receptivity and menstruation. Alterations in the paracrine endometrial system may underlie pathological processes such as infertility or endometrial neoplasia. The human placenta and its related membranes produce cytokines, hormones and growth factors that participate in the control of gestational development as well as in the maternal-fetal adaptation to gestational diseases. There is increasing evidence that paracrine signaling plays a fundamental role in all spheres of female reproductive function, and future research will concentrate on clarifying which of these local mechanisms play a decisive role in both physiology and disease, thus giving rise to new therapeutic strategies.

Transforming growth factor-beta isoforms and receptors in endometriotic cysts of the human ovary

PROBLEM

The present study examined the presence and cellular distribution of transforming growth factor-beta1, 2, and 3 isoforms and their type I and II receptors in endometriotic cysts of the ovary, relative to their presence in normal endometrial tissue.

METHOD OF STUDY

Thirteen control samples of normal endometrium in the proliferative phase and 11 ovarian endometriotic cysts were examined by immunohistochemistry for transforming growth factor-beta1, 2, and 3 isoforms and their type I and II receptors.

RESULTS

Immunoreactivity for all ligands and receptors was detected in both normal endometrium and endometriotic cysts. Isoform-specific differences in immunostaining were not detected. Expression of all ligands and receptors was significantly increased in epithelial cells of endometriotic cysts compared with those of normal endometrium. On the other hand, stromal cells in normal endometrium and endometriotic cysts were only faintly immunostained. Inflammatory cells infiltrating among endometriotic stromal cells contained the highest immunostaining intensity for all ligands and receptors. We identified nearly all inflammatory cells as macrophages using a specific antibody.

CONCLUSIONS

These findings suggest that macrophages in endometriotic tissue are a major source of transforming growth factor-beta, which may be an important regulator of cell proliferation in endometriotic cysts through paracrine and autocrine actions.

TGF-beta 1 and IGF-1 expression in atrophic post-menopausal endometrium

OBJECTIVES

Endometrial cells may synthetize cytokines and growth factors which may modulate some of the molecular mechanisms of endometrial proliferation and differentiation.

PATIENTS AND METHODS

We investigated the role of transforming growth factor beta-1 (TGF-beta 1), insulin-like growth factor-1 (IGF-1) and relative receptors in five tissue samples from atrophic post-menopausal endometria. The control group was represented by proliferative and secretory endometria from 10 healthy, normally-menstratued women. TGF-beta 1 and IGF-1 m-RNA expression was evaluated by Northern hybridization analysis, while TGF-beta 1 and IGF-1 receptors distribution was studied by immunohistochemistry.

RESULTS

In atrophic endometria Northern hybridization analysis showed a significant decrease of IGF-1 expression, and an increase of TGF-beta 1 expression compared to proliferative and secretory endometria. By immunohistochemistry it was demonstrated that TGF-beta 1 and IGF-1 receptors were both localized in cell cytoplasm, mainly in the stromal compartment.

CONCLUSIONS

The results of our study would suggest a possible role of IGF-1 and TGF-beta 1 in maintaining the quiescent differentiative state of atrophic post-menopausal endometrium. The persistence of IGF-1 and TGF-beta 1 receptors in epithelial compartment could play a key role in proliferative response of atrophic endometrium to exogenous hormone replacement therapy (HRT) or endogenous intervening high estrogens levels.

Human endothelial cell migration is stimulated by urokinase plasminogen activator:plasminogen activator inhibitor 1 complex released from endometrial stromal cells stimulated with transforming growth factor beta1; possible mechanism for paracrine stimulation of endometrial angiogenesis

Human endometrial stromal cell cultures, stimulated for two days with recombinant transforming growth factor beta1 (TGFbeta1; 10 ng/ml), contained conditioned medium concentrations of urokinase plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI1), and uPA:PAI1 complex. Since a number of cellular effects have been reported to follow a binding of enzymatically inactive uPA to the receptor in different cell types, we studied the influence of uPA:PAI1 complex on human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC-1). Increasing concentrations of uPA:PAI1 complex as well as free uPA resulted in a dose-dependent stimulation of endothelial cell migration. Stimulation by the complex was of the same magnitude as that of free uPA on a molar basis and reached its maximum at 1 nM in both cell types. PAI1 by itself, however, had no effect on cell migration. The migratory response to both uPA and the uPA:PAI1 complex was inhibited by antibody adhesion to the cell surface receptor for uPA. In addition, we found that TGFss1 had a direct stimulatory effect on migration in both HUVEC and HMEC-1. This response did not, however, involve the binding of uPA to the uPA receptor. Since TGFbetas are expressed in endometrial tissue and reportedly stimulate angiogenesis in other tissues in vivo, though not endothelial cell proliferation in vitro, they may engage in the regeneration of endometrial vasculature indirectly via perivascular cells. We found that the uPA:PAI1 complex, when released from endometrial stromal cells in response to TGFbeta1, stimulated endothelial cell migration. This suggests a possible mechanism for paracrine stimulation of endometrial angiogenesis.

Down-regulated expression of transforming growth factor beta 1 mRNA in endometrial carcinoma

Transforming growth factor beta1 (TGF-beta1) is a potent modulator of cell proliferation in vitro, and recent studies have demonstrated its overexpression in several different tumours; nevertheless, the molecular mechanisms of TGF-beta1 action on cell growth and differentiation have not been fully elucidated. To clarify the role of TGF-beta and its receptor in human endometrial proliferation and differentiation, TGF-beta1 expression at both the mRNA and protein levels has been evaluated by using Northern blotting and immunohistochemistry, in both normal (atrophic, proliferative and secretory) and neoplastic (adenocarcinoma) endometrial samples. This study demonstrates that TGF-beta1 mRNA expression is dramatically reduced in endometrial carcinomas with respect to non-neoplastic tissues, whereas the immunohistochemical expression of TGF-beta1 is enhanced in the epithelial component of endometrial carcinomas compared with non-neoplastic tissues. These data suggest that TGF-beta1 acts as a paracrine regulator of endometrial cell proliferation and that it may contribute to the carcinogenic mechanisms of endometrial carcinoma.

Transforming growth factor beta mediates the progesterone suppression of an epithelial metalloproteinase by adjacent stroma in the human endometrium

Unlike most normal adult tissues, cyclic growth and tissue remodeling occur within the uterine endometrium throughout the reproductive years. The matrix metalloproteinases (MMPs), a family of structurally related enzymes that degrade specific components of the extracellular matrix are thought to be the physiologically relevant mediators of extracellular matrix composition and turnover. Our laboratory has identified MMPs of the stromelysin family in the cycling human endometrium, implicating these enzymes in mediating the extensive remodeling that occurs in this tissue. While the stromelysins are expressed in vivo during proliferation-associated remodeling and menstruation-associated endometrial breakdown, none of the stromelysins are expressed during the progesterone-dominated secretory phase of the cycle. Our in vitro studies of isolated cell types have confirmed progesterone suppression of stromal MMPs, but a stromal-derived paracrine factor was found necessary for suppression of the epithelial-specific MMP matrilysin. In this report, we demonstrate that transforming growth factor beta (TGF-beta) is produced by endometrial stroma in response to progesterone and can suppress expression of epithelial matrilysin independent of progesterone. Additionally, we find that an antibody directed against the mammalian isoforms of TGF-beta abolishes progesterone suppression of matrilysin in stromal-epithelial cocultures, implicating TGF-beta as the principal mediator of matrilysin suppression in the human endometrium.

Regulation of monocyte chemotactic protein-1 gene expression in human endometrial cells in cultures

Bone marrow-derived leukocytes are present in human endometrium/decidua and are believed to serve a variety of functions in this tissue. The number and type of leukocytes in endometrium/decidua vary with the hormonal milieu of the ovarian cycle, with blastocyst implantation, and during pregnancy. The factors that regulate the recruitment of specific leukocytes to the endometrium and those that modulate the function or replication of leukocytes in this tissue are not well defined. In this study, we evaluated the potential for synthesis of monocyte chemotactic protein-1 (MCP-1), a polypeptide with monocyte/macrophage chemotactic and activating properties, in human endometrium and in separated endometrial stromal and epithelial cells. MCP-1 mRNA was readily detected by northern analysis of total RNA isolated from human endometrial tissue (n = 39 tissues from ovulatory women; n = 3 atrophic endometria from anovulatory women; n = 6 from women ingesting oral contraceptives or medroxyprogesterone acetate) and decidua parietalis at midtrimester (n = 6 pregnancies) and at term (n = 6 pregnancies). The levels of MCP-1 mRNA varied considerably among tissues; but in this relatively small number of samples, there was no apparent relationship between day of cycle, endocrine status, or duration of pregnancy and the level of MCP-1 mRNA. MCP-1 mRNA was detected in separated endometrial stromal cells and epithelial cells in culture. In confluent human endometrial stromal cells in the absence or presence of fetal bovine serum (10%, v/v), MCP-1 mRNA was detected by northern analysis of total RNA.(ABSTRACT TRUNCATED AT 250 WORDS)