Regulation of 72-kd type IV collagenase-matrix metalloproteinase-2 by estradiol and gonadotropin-releasing hormone agonist in human granulosa-lutein cells

Nuclear Receptor Atlases of Choroidal Tissues Reveal Candidate Receptors Associated with Age-Related Macular Degeneration

The choroid is a vulnerable tissue site in the eye, impacted in several blinding diseases including age related macular degeneration (AMD), which is the leading cause of central vision loss in the aging population. Choroidal thinning and choriocapillary dropout are features of the early form of AMD, and endothelial dysfunction and vascular changes are primary characteristics of the neovascular clinical sub-type of AMD. Given the importance, the choroidal endothelium and outer vasculature play in supporting visual function, a better understanding of baseline choroidal signaling pathways engaged in tissue and cellular homeostasis is needed. Nuclear receptors are a large family of transcription factors responsible for maintaining various cellular processes during development, aging and disease. Herein we developed a comprehensive nuclear receptor atlas of human choroidal endothelial cells and freshly isolated choroidal tissue by examining the expression levels of all members of this transcription family using quantitative real time PCR. Given the close relationship between the choroid and retinal pigment epithelium (RPE), this data was cross-referenced with the expression profile of nuclear receptors in human RPE cells, to discover potential overlap versus cell-specific nuclear receptor expression. Finally, to identify candidate receptors that may participate in the pathobiology of AMD, we cataloged nuclear receptor expression in a murine model of wet AMD, from which we discovered a subset of nuclear receptors differentially regulated following neovascularization. Overall, these databases serve as useful resources establishing the influence of nuclear receptor signaling pathways on the outer vascular tissue of the eye, while providing a list of receptors, for more focused investigations in the future, to determine their suitability as potential therapeutic targets for diseases, in which the choroid is affected.

Effects of lisinopril treatment on the pathophysiology of PCOS and plasminogen activator inhibitor-1 concentrations in rats

RESEARCH QUESTION

Angiotensin-converting enzyme inhibition results in a significant reduction in plasma concentrations of plasminogen activator inhibitor-1 (PAI-1). What are the effects of lisinopril treatment on PAI-1 concentrations and the morphology and function of the ovaries in the letrozole-induced polycystic ovary syndrome (PCOS) rat model?

DESIGN

This prospective randomized controlled animal study involved female Wistar albino rats. Twelve rats were assigned as controls (group I). In the study group (n = 48), letrozole (an aromatase inhibitor) was administered for PCOS modelling for 9 weeks. After confirming disrupted oestrous cycles, the study group was randomized into two groups: group II (n = 24; letrozole only) and group III (n = 24; letrozole + lisinopril 15 mg/kg per day). After 12 weeks, each group was divided randomly into two. Biochemical, histopathological and immunohistochemical analyses was performed in subgroups designated A, and fertilization rates were studied in subgroups designated B.

RESULTS

Lisinopril treatment reduced the weight and area of the ovaries, the number and wall thickness of cystic follicles, and serum concentrations of LH and testosterone, relative to group II (P < 0.001). Circulating PAI-1 concentrations were significantly different among three groups (7.7 ± 0.9 ng/ml, 9.8 ± 0.7 ng/ml and 8.6 ± 0.7 ng/ml for groups IA, IIA and IIIA; P < 0.001). Pregnancy rates were 100%, 0% and 16.7% in groups IB, IIB and IIIB.

CONCLUSIONS

In the letrozole-induced rodent PCOS model, lisinopril modifies the action of letrozole, possibly by inhibition of systemic and ovarian production of PAI-1. The use of PAI-1 inhibitors deserves further investigation in understanding the pathogenesis of PCOS.

Matrix Metallopeptidase-2 Gene rs2287074 Polymorphism is Associated with Brick Tea Skeletal Fluorosis in Tibetans and Kazaks, China

Brick tea skeletal fluorosis is still a public health issue in the north-western area of China. However its pathogenesis remains unknown. Our previous study reveals that the severity of skeletal fluorosis in Tibetans is more serious than that in Kazaks, although they have similar fluoride exposure, suggesting the onset of brick tea type skeletal fluorosis might be genetically influenced. Here we show that MMP-2 rs2287074 SNP (G/A), but not rs243865, was associated with Brick tea type fluorosis in Tibetans and Kazaks, China. The trend test reveals a decline in probability for skeletal fluorosis with increasing number of A alleles in Tibetans. After controlling potential confounders, AA genotype had about 80 percent lower probability of developing skeletal fluorosis than GG genotype in Tibetans (odds ratio = 0.174, 95% CI: 0.053, 0.575), and approximately 53 percent lower probability in Kazaks (odds ratio = 0.462, 95% CI: 0.214, 0.996). A meta-analysis shows that the AA genotype had approximately 63 percent lower odds (odds ratio = 0.373, 95% CI: 0.202, 0.689) compared with GG genotype within the two ethnicities. A significant correlation was also found between the genotype of MMP2 rs2287074 and skeletal fluorosis severity. Therefore, the A allele of MMP2 rs2287074 could be a protective factor for brick tea skeletal fluorosis.

Effects of 17β-estradiol on human corneal wound healing in vitro

PURPOSE

To investigate the effect of 17β-estradiol on corneal wound healing, particularly on epithelial mitosis and migration.

METHODS

Immortalized human corneal epithelial cells (HCECs) were cultured in media with different concentrations of 17β-estradiol (10, 50, 100, and 200 pg/mL), Dulbecco modified Eagle medium: Nutrient Mixture F-12 (negative control), and serum-containing Dulbecco modified Eagle medium: Nutrient Mixture F-12 (positive control). After 6 or 24 hours of hormone treatment, to evaluate the migratory potential of 17β-estradiol, wound healing assays were conducted via the manual scraping of HCECs and western blot analysis of fibronectin and matrix metalloproteinase 9 (MMP9). The proliferative potential of 17β-estradiol was evaluated via a proliferation assay using western blot analysis for proliferating cell nuclear antigen. In addition, epidermal growth factor (EGF) was measured by reverse transcription-polymerase chain reaction, and for the inhibition of epidermal growth factor receptor (EGFR)-mediated signal transduction, a wound healing assay was conducted after HCECs cultured with EGFR small interfering RNA were stimulated with 100 pg/mL 17β-estradiol.

RESULTS

Wound healing assay rates were enhanced as 17β-estradiol increased, with statistically significant changes seen in 50, 100, and 200 pg/mL 17β-estradiol-treated and positive control cells, compared with negative control cells (P < 0.05, in each group). Western blot analysis revealed that the expression of the MMP9 gene was upregulated by 17β-estradiol, and the expression of the fibronectin gene was downregulated by 17β-estradiol. The mitosis assay via western blot analysis showed that the expression cell cycle-associated protein, proliferating cell nuclear antigen, increased gradually as a result of 17β-estradiol treatment. Reverse transcription-polymerase chain reaction showed that EGF was upregulated by 17β-estradiol, and the EGFR small interfering RNA did not totally block the wound healing of the 17β-estradiol-treated cells but statistically significantly reduced the wound healing rate (P = 0.031).

CONCLUSIONS

17β-Estradiol facilitated the maintenance of the beneficial effect on corneal epithelial migration and proliferation, and the promoting effect of 17β-estradiol is partially related to increased EGF in vitro.

Retinal pigment epithelium response to oxidant injury in the pathogenesis of early age-related macular degeneration

Age-related macular degeneration (AMD) represents the leading cause of vision loss in the elderly. Accumulation of lipid- and protein-rich deposits under the retinal pigment epithelium (RPE) heralds the onset of early AMD, but the pathogenesis of subretinal deposit formation is poorly understood. Numerous hypothetical models of deposit formation have been proposed, including hypotheses for a genetic basis, choroidal hypoperfusion, abnormal barrier formation, and lysosomal failure. This review explore the RPE injury hypothesis, characterized by three distinct stages (1) Initial RPE oxidant injury, caused by any number of endogenous or exogenous oxidants, results in extrusion of cell membrane "blebs," together with decreased activity of matrix metalloproteinases (MMPs), promoting bleb accumulation under the RPE as basal laminar deposits (BLD). (2) RPE cells are subsequently stimulated to increase synthesis of MMPs and other molecules responsible for extracellular matrix turnover (i.e., producing decreased collagen), affecting both RPE basement membrane and Bruchs membrane (BrM). This process leads to progression of BLD into basal linear deposits (BLinD) and drusen by admixture of blebs into BrM, followed by the formation of new basement membrane under the RPE to trap these deposits within BrM. We postulate that various hormones and other plasma-derived molecules related to systemic health cofactors are implicated in this second stage. (3) Finally, macrophages are recruited to sites of RPE injury and deposit formation. The recruitment of nonactivated or scavenging macrophages may remove deposits without further injury, while the recruitment of activated or reparative macrophages, through the release of inflammatory mediators, growth factors, or other substances, may promote complications and progression to the late forms of the disease.

Differential release of matrix metalloproteinases and tissue inhibitors of metalloproteinases by human granulosa-lutein cells and ovarian leukocytes

Tissue reorganization during ovulation and corpus luteum formation involves a coordinated action of matrix metalloproteinases (MMPs) and tissue MMP inhibitors (TIMPs). In this study we investigated the cellular source of ovarian MMPs and TIMPs. Cells isolated from the preovulatory human follicle were cultured after immunobead depletion of CD45-expressing cells, which allowed differential assessment of leukocyte and granulosa-lutein cell fractions. Secretion of MMP-9 by follicular fluid-derived cells was associated with the presence of leukocytes. Granulosa-lutein cells synthesized low levels of MMP-9 but failed to secrete this enzyme that presumably accumulated in the cytoplasm, indicated by an increased MMP-9 expression of luteinized cells in sectioned midluteal phase corpora lutea. Synthesis and secretion of TIMP by follicular fluid-derived cells was associated with granulosa-lutein cells. TIMPs derived by granulosa-lutein cells failed to inhibit MMP-related pericellular proteolysis. The findings support a two-cell model of periovulatory MMP/TIMP release, in which leukocytes secrete MMPs and granulosa-lutein cells release TIMP, suggesting that there exists an intriguing interaction among cells that intertwingle during ovulation and corpus luteum formation.

Cytokine regulation during the formation of the fetal-maternal interface: focus on cell-cell adhesion and remodelling of the extra-cellular matrix

The establishment of human pregnancy requires the orchestration of substantial cell differentiation and tissue remodelling processes in the context of a complex dialogue between the receptive endometrium and the implanting blastocyst, and is therefore dependent upon a complex sequence of signalling events. Cytokines play an important role in each step of implantation, modulating expression of adhesion molecules on both the fetal and maternal surfaces, regulating expression of the proteases that remodel the extra-cellular matrix, and promoting invasion and differentiation of trophoblasts. Here we review the role of cytokines in regulating the establishment of the fetal-maternal interface, with a particular focus on regulation of the functional expression of CAMs, the ECM and of the proteinases that modulate their function.

Mechanisms of matrix metalloproteinase-2 (mmp-2) transcriptional repression by progesterone in jar choriocarcinoma cells

BACKGROUND

Although the MMP-2 promoter lacks a canonical progesterone response element (PRE), the hormone inhibits MMP-2 expression and is part of treatment protocols in gynecological invasive pathologies, including endometriosis and endometrial hyperplasia. This study aimed to explore the mechanism by which progesterone inhibits MMP-2 expression.

METHODS

The effect of progesterone on MMP-2 expression in the JAR human choriocarcinoma cell line was analyzed by gelatin zymography. MMP-2 transcript expression was studied using Northern blot and semi-quantitative RT-PCR. Rat promoter deletion analysis, electrophoretic mobility shift and chromatin immuno-precipitation assays were performed in order to locate the DNA binding site and the transcription factors involved in MMP-2 regulation.

RESULTS

Progesterone significantly decreased secretion of pro-MMP-2 and MMP-2 transcript expression level in a dose-dependent manner. Progesterone (1 microM) significantly decreased both human and rat MMP-2 promoter activity (80.1% +/- 0.3 and 81.3% +/- 0.23, respectively). Progesterone acts through the SP1 family transcription factors-binding site, located between -1433 and -1342 bp region from the transcriptional start site of the rat MMP-2 promoter, which are present in the orthologous human MMP-2 promoter. Progesterone receptor (PR), SP2, SP3 and SP4 proteins are constitutively bound to this consensus sequence.

CONCLUSION

Progesterone reduces PR and SP4 binding to the MMP-2 promoter, thereby suppressing transcription. Progesterone also promotes SP4 degradation. These novel mechanisms of MMP-2 regulation by progesterone provide the biological rationale for the use of progesterone in clinical settings associated with increased MMP-2 expression.

Estrogen up-regulation of metalloproteinase-2 and -9 expression in rabbit lacrimal glands

Increased levels of the matrix metalloproteinases (MMPs)-2 and -9 have been found in tear fluids of patients with dry eye disease, suggesting that these MMPs may be implicated in the pathogenesis of this disease. One of the main causes of dry eye disease is lacrimal gland insufficiency. However, the contribution of the lacrimal gland (LG) to the expression and production of MMP-2 and MMP-9 in tears is not known. Since dry eye disease occurs more frequently in women, sex hormones, especially estrogens, have also been implicated in the pathogenesis of this disease. Estrogens have been shown to regulate the synthesis levels of MMP-2 and MMP-9 in several tissues, Thus, the purpose of these studies was to determine if: (1) rabbit lacrimal glands secrete MMP-2 and MMP-9; (2) MMP-2 and MMP-9 are produced by lacrimal epithelial cells and/or lacrimal lymphocytes; and (3) the expression, activity and level of these enzymes are regulated by sex hormones. Lacrimal epithelial cells (LEC) and lacrimal lymphocytes (LL) from sexually mature New Zealand White female rabbits were isolated, purified and cultured with and without 10(-6)M dihydrotestosterone (DHT) or 10(-6), 10(-8), 10(-9) and 10(-10)M 17beta-estradiol (E2). The culture supernatants were analyzed by zymography and western blotting (WB) using polyclonal anti-human MMP-2 and MMP-9 antibodies. LGs were also collected from rabbits 7 days after being sham-operated, ovariectomized (OVX), OVX treated with 4 mg/kg DHT, and OVX treated with 0.5 mg/kg of E2. LGs were collected and processed for RNA extraction as well as protein determination using WB and immunocytochemistry. The pro-forms of MMP-2 and MMP-9 were detected in primary LEC and LL culture medium by zymography and WB. Pro-MMP-2 and pro-MMP-9 were also detected at the gene and protein levels in the lacrimal glands of all four treatment groups, with the highest levels and gene expression found in the estrogen-treated group. These results suggest that both pro-MMP-2 and pro-MMP-9 are secreted by the lacrimal gland and appear to be up-regulated by estrogen. The role of the lacrimal MMPs in the pathogenesis of dry eye disease needs to be further investigated.

Gelatinases, endonuclease and Vascular Endothelial Growth Factor during development and regression of swine luteal tissue

BACKGROUND

The development and regression of corpus luteum (CL) is characterized by an intense angiogenesis and angioregression accompanied by luteal tissue and extracellular matrix (ECM) remodelling. Vascular Endothelial Growth Factor (VEGF) is the main regulator of angiogenesis, promoting endothelial cell mitosis and differentiation. After the formation of neovascular tubes, the remodelling of ECM is essential for the correct development of CL, particularly by the action of specific class of proteolytic enzymes known as matrix metalloproteinases (MMPs). During luteal regression, characterized by an apoptotic process and successively by an intense ECM and luteal degradation, the activation of Ca++/Mg++-dependent endonucleases and MMPs activity are required. The levels of expression and activity of VEGF, MMP-2 and -9, and Ca++/Mg++-dependent endonucleases throughout the oestrous cycle and at pregnancy were analyzed.

RESULTS

Different patterns of VEGF, MMPs and Ca++/Mg++-dependent endonuclease were observed in swine CL during different luteal phases and at pregnancy. Immediately after ovulation, the highest levels of VEGF mRNA/protein and MMP-9 activity were detected. On days 5-14 after ovulation, VEGF expression and MMP-2 and -9 activities are at basal levels, while Ca++/Mg++-dependent endonuclease levels increased significantly in relation to day 1. Only at luteolysis (day 17), Ca++/Mg++-dependent endonuclease and MMP-2 spontaneous activity increased significantly. At pregnancy, high levels of MMP-9 and VEGF were observed.

CONCLUSION

Our findings, obtained from a precisely controlled in vivo model of CL development and regression, allow us to determine relationships among VEGF, MMPs and endonucleases during angiogenesis and angioregression. Thus, CL provides a very interesting model for studying factors involved in vascular remodelling.

Estrogen Stimulation of Proinflammatory Cytokine and Matrix Metalloproteinase Gene Expression in Human Corneal Epithelial Cells

PURPOSE

Researchers have proposed that the secretion of proinflammatory cytokines and matrix metalloproteinases (MMPs) by corneal epithelial cells contributes to the development of ocular surface inflammation in dry eye syndromes. We hypothesize that this cytokine and MMP production is promoted by estrogens, given that dry eye syndromes occur predominantly in women and estrogen therapy is associated with an increase in dry eye signs and symptoms. Moreover, corneal epithelial cells contain estrogen receptors and estrogens are known to influence other aspects of corneal immunity. The purpose of this study was to test our hypothesis.

METHODS

Immortalized human corneal epithelial cells were exposed to vehicle, lipopolysaccharide (LPS), or varying concentrations of 17beta-estradiol. After 6 or 24 hours of hormone treatment, cells were harvested and processed for total RNA isolation, cDNA synthesis, and the analysis of cytokine and MMP mRNA levels by multiplex and real-time PCR methods.

RESULTS

Our results demonstrate that 17beta-estradiol upregulates the expression of proinflammatory cytokine and MMP genes in human corneal epithelial cells. Estrogen administration significantly increased the levels of IL-1beta, IL-6, IL-8, and GM-CSF mRNAs, as well as MMP 2, 7, and 9 mRNAs, compared with those of placebo-treated controls. This estrogen effect was found after 6 and/or 24 hours of hormone treatment. An analogous stimulation of gene expression was observed following cellular exposure to LPS.

CONCLUSIONS

Our findings show that 17beta-estradiol increases the expression of inflammatory genes in human corneal epithelial cells. This hormone action may play an etiologic role in the ocular surface inflammation of dry eye.

Gelatinases A and B (MMP-2 and MMP-9) in endometrial cancer—MMP-9 correlates to the grade and the stage

OBJECTIVE

Matrix metalloproteinases (MMPs) have been linked to aggressive behavior in several malignancies. Gelatinases (MMP-2 and MMP-9) in particular are prognostic factors in many adeno- and epithelial cancers. However, no conclusive data exist concerning the role of gelatinases in endometrial cancer.

METHODS

Eighty-eight patients with endometrial cancer, treated between 1988 and 1993 in Umeå University Hospital, were included. MMP-2 and MMP-9 proteins were analyzed immunohistochemically from paraffin-embedded tissues by using specific monoclonal antibodies. The staining results were compared to the clinical data.

RESULTS

Fifty-two percent of the cases were positive for MMP-9 and 72% for MMP-2. The overexpression of the proteins of either MMP-2 or MMP-9 was associated with poor survival. The predictive value of MMP-2 expression was most distinct in stage I cancers. An association was found between the positivity of MMP-2 and MMP-9. Only 3% of the cases were highly positive for both gelatinases and 18% of the cases were negative for both MMPs. Both gelatinases correlated to the histological grade. MMP-9 also correlated to the clinical stage of the disease, whereas MMP-2 did not. There was no apparent association with either depth of invasion, menopausal status, or the age of the patient.

CONCLUSION

MMP-2 and MMP-9 could serve as markers for the clinical behavior of endometrial cancer. They may further be linked to a tendency to cancer relapse. Thus, these gelatinases may turn out to be potentially useful in decision making about the need for an adjuvant treatment.

Matrix metalloproteinase 2 is associated with changes in steroid hormones in the sera and peritoneal fluid of patients with endometriosis

OBJECTIVE

To determine matrix metalloproteinase 2 (MMP-2) levels in sera and peritoneal fluids of women with or without endometriosis-associated infertility and to determine whether MMP-2 had correlation with 17beta-E(2) and P in the sera and peritoneal fluids of the patients with endometriosis.

DESIGN

A case-control study.

SETTING

A women's hospital in China.

PATIENT(S)

Forty patients with endometriosis-associated infertility undergoing laparoscopy and 18 women undergoing tubal ligation.

INTERVENTION(S)

Sera and peritoneal fluids were collected from women with or without endometriosis.

MAIN OUTCOME MEASURE(S)

Matrix metalloproteinase 2, 17beta-E(2), and P concentration.

RESULT(S)

Compared with the control women, the patients with endometriosis had higher MMP-2 levels in their sera and peritoneal fluids. Serum and peritoneal fluid MMP-2 levels were higher in the proliferative phase than in the secretory phase. The level of MMP-2 in the patients was correlated positively with 17beta-E(2) in serum and peritoneal fluid and negatively with P.

CONCLUSION(S)

The results demonstrated a correlation between MMP-2 concentrations and steroid hormones in sera and peritoneal fluids of the patients with endometriosis-associated infertility. Estradiol might up-regulate MMP-2, resulting in the formation of endometriosis. Progesterone might down-regulate MMP-2 to inhibit the formation and development of endometriosis.

Matrix metalloproteinase-2 (MMP-2) expression and regulation by tumor necrosis factor alpha (TNF?) in the bovine corpus luteum

Angiogenesis and tissue remodeling events in the corpus luteum (CL) are mediated by matrix metalloproteinases (MMPs). We have recently reported the cloning of bovine membrane-type 1 metalloproteinase (MT1-MMP) and have shown that active MT1-MMP is correlated to MMP-2 activity in the CL during the estrous cycle. Given the important role that MMP-2 plays in neovascularization, we became interested in understanding the role of this enzyme in the CL, a system in which angiogenesis is exquisitely regulated in the course of its lifespan. The aims of the present study were to clone bovine MMP-2 cDNA, to investigate its temporal and spatial expression in three stages of CL during the estrous cycle and to study its regulation by TNFalpha, a key cytokine regulator of CL physiology. Bovine MMP-2 cDNA was isolated from a UNI-ZAP II bovine capillary endothelial cell cDNA library and sequenced. This gene encoded a protein of 662 amino acids. Luteal tissues were collected from non-lactating dairy cows on days 4, 10, and 16 of the estrous cycle. Northern and Western blotting revealed that the levels of MMP-2 mRNA (3.1 kb) and immunoreactive pro-MMP-2 protein (68 kDa) did not differ (P > 0.05) in any age of CL examined. In addition to large luteal cells, MMP2 was localized to endothelial cells in all ages of CL by immunohistochemistry. Studies using in vitro luteal cell cultures showed that MMP-2 mRNA, protein expression and activity was upregulated by TNFalpha in a dose- and time-dependent manner. The present study suggests that MMP-2 is predominantly produced by large luteal cells and endothelial cells, and that it plays an essential role in luteal remodeling and angiogenesis. These data also suggest that cytokines such as TNFalpha may modulate these processes by regulating MMP-2 expression.

The role of estrogen in cardiovascular disease

Cardiovascular disease is the number one cause of death among women, accounting for nearly 50% of female deaths. Statistics show that women on average develop cardiovascular disease 10 to 15 years later in life than men, and that the risk may increase after menopause. This observation has led to much speculation as to what physiological change(s) associated with menopause is responsible for the higher risk of atherosclerosis. Estrogen, with its potential as a cardioprotective agent and as an immunomodulator of the inflammatory response in atherosclerosis, has received the most attention. Understanding the mechanisms that lead to these differences may allow beneficial therapeutic intervention to enhance this effect in females and evoke this protection in males. This review will do the following: (1) characterize mechanisms of atherosclerosis, (2) explore the role of estrogen-replacement therapy, (3) define the effect of gender on inflammation, (4) compare and contrast the effects of estrogen and testosterone on endothelial functional, and (5) suggest mechanistic based therapeutic opportunities.

Linked common polymorphisms in the gelatinase a promoter are associated with diminished transcriptional response to estrogen and genetic fitness

Gelatinase A (matrix metalloproteinase-2) plays a prominent role in multiple biologic processes. Prior studies have established critical roles for gelatinase A transcriptional regulation by defined enhancer elements. To determine possible functional single nucleotide polymorphisms within these elements, we determined the single nucleotide polymorphism distribution within 1,665 bp of the gelatinase A 5'-flanking region, using a healthy homogeneous Caucasian study group of 463 individuals. Among the polymorphisms detected, a G --> A transition at bp -1575 was located immediately 5' to a half-palindromic potential estrogen receptor binding site. In estrogen receptor-positive MCF-7 cells the -1575G allele functioned as an enhancer, whereas the -1575A allele reduced transcription activity significantly. Gel shift assays confirmed that the differences in allelic expression affected binding of the estrogen receptor-alpha to this region. Cotransfection experiments with an estrogen receptor-alpha expression vector in MDA-MB-231 cells, which do not constitutively express an estrogen receptor, revealed that estrogen receptor is absolutely required for enhancing activity. Allelic distribution analysis indicated that a previously reported C --> T transition within an Sp1 binding site at -1306 was in linkage disequilibrium with the -1575G --> A transition. Luciferase reporter studies of the linked variant -1575A -1306T allele versus the wild type -1575G -1306C allele demonstrated an additive reduction in estrogen-dependent reporter activity. The frequency of the -1575G --> A transition deviated significantly from the expected Hardy-Weinberg distribution in two independently assembled study populations consisting of healthy adult blood donors and newborns of Caucasian origin, both with a calculated 21% reduction in genetic fitness. Gelatinase A is a known estrogen-responsive gene and the demonstration of a loss of function polymorphism within an operational estrogen receptor binding site associated with a decrease in genetic fitness underscores the biologic significance of promoter polymorphism analyses.

Linked common polymorphisms in the gelatinase a promoter are associated with diminished transcriptional response to estrogen and genetic fitness

Gelatinase A (matrix metalloproteinase-2) plays a prominent role in multiple biologic processes. Prior studies have established critical roles for gelatinase A transcriptional regulation by defined enhancer elements. To determine possible functional single nucleotide polymorphisms within these elements, we determined the single nucleotide polymorphism distribution within 1,665 bp of the gelatinase A 5'-flanking region, using a healthy homogeneous Caucasian study group of 463 individuals. Among the polymorphisms detected, a G --> A transition at bp -1575 was located immediately 5' to a half-palindromic potential estrogen receptor binding site. In estrogen receptor-positive MCF-7 cells the -1575G allele functioned as an enhancer, whereas the -1575A allele reduced transcription activity significantly. Gel shift assays confirmed that the differences in allelic expression affected binding of the estrogen receptor-alpha to this region. Cotransfection experiments with an estrogen receptor-alpha expression vector in MDA-MB-231 cells, which do not constitutively express an estrogen receptor, revealed that estrogen receptor is absolutely required for enhancing activity. Allelic distribution analysis indicated that a previously reported C --> T transition within an Sp1 binding site at -1306 was in linkage disequilibrium with the -1575G --> A transition. Luciferase reporter studies of the linked variant -1575A -1306T allele versus the wild type -1575G -1306C allele demonstrated an additive reduction in estrogen-dependent reporter activity. The frequency of the -1575G --> A transition deviated significantly from the expected Hardy-Weinberg distribution in two independently assembled study populations consisting of healthy adult blood donors and newborns of Caucasian origin, both with a calculated 21% reduction in genetic fitness. Gelatinase A is a known estrogen-responsive gene and the demonstration of a loss of function polymorphism within an operational estrogen receptor binding site associated with a decrease in genetic fitness underscores the biologic significance of promoter polymorphism analyses.

Clinical cardiovascular studies of hormone replacement therapy

Coronary artery disease (CAD) is the number 1 cause of death and disability in the Western world. The incidence of CAD increases with age, although, on average, women present with symptomatic CAD about 10 years later than men. The belief that hormone replacement therapy (HRT) may reduce the incidence of CAD is based on its favorable effects on (1) vasoreactivity, (2) progression of atherosclerosis, (3) lipids and lipoproteins, (4) hemostasis, and (5) impaired glucose tolerance. However, unopposed estrogen may be related to an increased risk of endometrial cancer. The belief that HRT has an overall beneficial effect on cardiovascular disease comes from the results of prospective cohort studies. The Heart and Estrogen/progestin Replacement Study (HERS), however, showed no beneficial effect of HRT on cardiovascular morbidity and mortality. Uncertainty exists about the duration and optimal type of HRT regimen to use, because different estrogens and progestins have yielded different results. Results of ongoing trials addressing similar questions will be published in future years. The Women's Hormone Intervention Secondary Prevention (WHISP) pilot study, using a different HRT regimen from that used in HERS, will assess the effect of HRT on lipid and hemostatic risk markers of heart disease, and it may provide the rationale for a large trial evaluating the effect of HRT on morbidity and mortality.

Bovine follicular fluid and serum share a unique isoform of matrix metalloproteinase-2 that is degraded by the oviductal fluid

Whereas the mammalian fertilization environment consists of possible products of the mutual interaction between oviductal and follicular fluids in addition to both fluid components, little is known regarding the interaction. In the present study, we have demonstrated that a mutual interaction occurs, resulting in the biochemical changes of follicular fluid components. Gelatin zymographic analyses of bovine follicular fluid (bFF) showed consistently a distinct, gelatinolytic activity having a molecular weight of 110 kDa (GA110) in addition to other gelatinases, whereas bovine oviductal fluid (bOF) showed a lack of GA110. Surprisingly, when bFF was mixed with bOF before zymography, the GA110 of bFF mostly disappeared at a 1:1 (v/v) mixture, completely disappeared at a 1:10 mixture, as fast as within 30 min after mixing. Other bFF gelatinase activities were not affected by bOF at 1:1 or 10:1 mixtures. Addition of EDTA or phenanthroline, but not of phenylmethylsulfonyl fluoride or trypsin inhibitor, to the mixture greatly increased the gelatinolytic activity of bFF GA110. The increased activity of bFF GA110 by EDTA was again abolished by subsequent bOF treatment. Addition of aminophenylmercuric acetate to the EDTA-treated bFF also abolished GA110; however, this was accompanied by the disappearance of other gelatinases, except the 62-kDa gelatinase, the activity of which increased as the treatment continued up to 24 h. Addition of EDTA or phenanthroline to the gelatin gel incubation buffer after electrophoresis abolished almost all gelatinases of bFF, except those of 88-84 kDa, demonstrating that they were indeed gelatinases or isoforms. Bovine serum and fetal bovine serum also showed the presence of GA110, the activity of which was increased by EDTA. However, ovarian granulosa cell homogenate did not exhibit GA110. Immunoblot experiments using antibodies against matrix metalloproteinase (MMP)-2 and MMP-9 demonstrated that bFF GA110 was an isoform of MMP-2, and that the 62-kDa form was an active form of MMP-2. Disappearance of immunoreactive GA110 of bFF and serum by bOF was also observed. Based on these observations, we conclude that bFF and bovine serum share a unique isoform of MMP-2, and that bOF can specifically degrade the isoform, suggesting that a mutual interaction between bFF and bOF could occur at the time of ovulation.

Oestrogens and wound healing

During the past few decades several studies have documented the deleterious impact of the menopause on bone mass and cardiovascular disease, and the reduction of risk in this area by HRT. However, the possible effects of the postmenopausal deficiency in ovarian hormones on skin and its repair post-injury, are less well documented. This review provides a survey of the literature that is available regarding the involvement and influence of oestrogens on the various phases of cutaneous repair - inflammation, proliferation and remodelling. Research carried out on the effects of oestrogens, both in terms of deficiency and replacement, on the process of wound healing in various animal models is described and discussed, together with the very limited work undertaken in humans. This area of research is of paramount clinical importance both in terms of financial cost and human suffering, since many chronic wounds such as venous ulcers, pressure sores and burns afflict the elderly population, of whom postmenopausal women comprise the majority. Clinically our aim should be to restore the integrity and function of wounded tissue as rapidly as possible after injury and it is generally believed that a better understanding of the effects of oestrogens on wound healing could lead to improved care of cutaneous wounds, and the treatment of not only the wound but of the postmenopausal woman as a whole.

Collagenase and gelatinase messenger ribonucleic acid expression and activity during follicular development in the rat ovary

Metalloproteinases are members of a family of proteinases that remodel the extracellular matrix throughout the body. To test the hypothesis that metalloproteinases are regulated by gonadotropin-induced changes during follicular growth, rats were injected with eCG (20 IU, s.c.), and ovaries and serum were collected at the time of eCG administration (0 h) and at 6, 12, 24, 36, or 48 h later for analysis of metalloproteinase mRNA expression, metalloproteinase activity, and steroidogenesis. Serum estradiol levels increased from 18.9 pg/ml at 0 h to 503.8 pg/ml at 48 h. Analysis of mRNA expression was performed for collagenase-3, 72-kDa gelatinase, and 92-kDa gelatinase (n = 3-4). For collagenase-3, eCG stimulated a 32-fold increase in collagenase-3 mRNA at 48 h after eCG injection as compared to that in ovaries collected at the time of eCG administration (i.e., 0-h control). The mRNA levels for 72-kDa gelatinase were 2.8-fold compared to 0 h at 36 h after eCG treatment and returned to control levels by 48 h after gonadotropin treatment. Levels of the 92-kDa mRNA expression peaked at 24 h (4. 2-fold compared to 0 h) and returned to control levels by 36 h. Gel zymography revealed 3 gelatinolytic bands corresponding to the gelatinases of approximately 72 kDa, 92 kDa, and 105 kDa. Analysis of metalloproteinase activity as the degradation of collagen or gelatin per ovary showed an increase in gelatinolytic and collagenolytic activity between 12 and 48 h after eCG treatment. In summary, these findings demonstrate that the gonadotropin induction of folliculogenesis results in changes in the metalloproteinases that may be responsible for extracellular matrix remodeling associated with follicular growth.

Gonadotropin and steroid regulation of steroid receptor and aryl hydrocarbon receptor messenger ribonucleic acid in macaque granulosa cells during the periovulatory interval

Although steroids play a local role(s) in ovulation and luteinization of the primate follicle, the dynamics of steroid receptor expression during the 36- to 38-h periovulatory interval has yet to be elucidated. The present study examines the regulation of messenger RNAs (mRNAs) for progesterone (PR), androgen (AR), and estrogen (ER alpha, ER beta) receptors as well as the aryl hydrocarbon receptor (AhR) in macaque granulosa cells during controlled ovarian stimulation cycles before (0 h) and after (up to 36 h) administration of the ovulatory hCG bolus with or without steroid depletion and progestin replacement. All steroid receptor mRNAs were detected in granulosa cells before the ovulatory stimulus, as determined by RT-PCR. PR mRNA increased (P < 0.05) by 12 h after hCG; 24 and 36 h after hCG, levels were intermediate between 0-12 h. PR mRNA was reduced by steroid depletion throughout the periovulatory interval (P < 0.05); however, progestin replacement returned PR mRNA to control levels at 12 h. AR mRNA increased (P < 0.05) at 24 h post-hCG and remained at this level 36 h after hCG; steroid depletion did not alter AR mRNA levels. ER alpha mRNA did not change, whereas ER beta decreased 12-36 h after the ovulatory stimulus (P < 0.05). Steroid depletion reduced ER alpha mRNA 12 h after hCG, an effect partially reversible by progestin replacement, whereas ER beta mRNA was not affected by steroids. AhR mRNA was undetectable before the administration of hCG, but increased by 12 h (P < 0.05). These data demonstrate hCG-initiated, steroid-dependent (PR, ER alpha) and -independent (AR, ER beta, AhR) expression of receptor mRNAs in primate granulosa cells during the periovulatory interval. Differences in patterns of expression may relate to diverse roles for steroid hormones and AhR ligands in periovulatory events.

Interstitial collagenase (MMP-1) activity in human ovarian tissue

The collagen content and collagenase activity were estimated in human ovarian interstitial tissue devoid of all visible follicles in menstruating, fertile as well as climacteric women. The mean total collagenase activity in ovarian specimens taken during both follicular (n = 10, 3.97 +/- 0.58 U/g wet weight, ww) and luteal phase (n = 10, 3.39 +/- 1.24 U/g ww) of the normal menstrual cycle along with total collagen concentration (184.8 +/- 41.0 vs. 194.4 +/- 30.5 micrograms/mg ww, respectively) did not differ. Total collagenase activity of climacteric gonads (n = 5, 1.55 +/- 0.71 U/g ww) was lower than in specimens collected during both follicular and luteal phase (p = 0.0002 and p = 0.017, respectively). About 23% of the total collagenase activity in follicular phase ovarian extracts and only about 1% in luteal phase ovarian preparations was found in the latent form. The percentage of latent collagenase in ovarian tissue during the follicular phase was negatively correlated with the day of the menstrual cycle (r = -0.93, p = 0.007). Extracellular matrix remodelling in the human ovary can be correlated with the functional status of the follicular unit.

Expression of matrix metalloproteinases and their tissue inhibitor messenger ribonucleic acids in macaque periovulatory granulosa cells: time course and steroid regulation

Progesterone appears essential for ovulation and luteinization of the primate follicle, but specific gene targets of progesterone action remain elusive. Limited evidence supports a role for progesterone in the induction of collagenolytic activity in the periovulatory follicle of primate and nonprimate species. This study was designed to elucidate the pattern of expression and progesterone regulation of mRNAs for the matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in macaque granulosa cells during controlled ovarian stimulation cycles before (0 h) and after (up to 36 h) administration of an ovulatory hCG bolus. Levels of mRNAs for interstitial collagenase, gelatinase A, matrilysin, TIMP-1 and TIMP-2 increased (p < 0.05) within 12 h of hCG, while gelatinase B mRNA increased later, by 36 h after hCG. Administration of a 3beta-hydroxysteroid dehydrogenase inhibitor (Trilostane [TRL]) during hCG treatment decreased (p < 0.05) mRNA levels for interstitial collagenase, gelatinase B, matrilysin, TIMP-1, and TIMP-2. Progestin (R5020) replacement during hCG+TRL treatment returned interstitial collagenase and TIMP-1 mRNAs to control levels. These data suggest that one action of progesterone, and possibly other steroids, in the cascade of events leading to ovulation and luteinization of the primate follicle is to regulate the expression of specific ovarian proteases and protease inhibitors.

Prognostic value of MMP-2 immunoreactive protein (72 kD type IV collagenase) in primary skin melanoma

The penetration of the subepithelial basement membrane is the first critical step in the dissemination of melanoma. In vitro studies have suggested that the 72 kD type IV collagenase (MMP-2) may be important in melanoma invasion. It has recently been demonstrated that the expression of MMP-2 immunoreactive protein increased with increasing atypia in melanocytic tumours and was associated with later haematogenous metastases in melanoma. This paper investigates the value of MMP-2 as a possible prognostic marker in melanoma. The expression of MMP-2 immunoreactive protein was studied with immunoperoxidase staining in paraffin-embedded sections of 50 cases of primary skin melanoma by using specific, affinity purified antibodies. Positive immunostaining was quantified by counting the percentage of positive cancer cells and was compared with clinical patient characteristics and survival. Sixty-four per cent of the primary melanoma cases displayed positive cytoplasmic immunostaining for MMP-2 in tumour cells. Marked overexpression of MMP-2 protein (> or = 34 per cent of melanoma cells positive) correlated with the 5-year survival of the patients when compared with patients with lower MMP-2 positivity, 55 per cent vs. 85 per cent, respectively (P < 0.05). Male patients displayed positive staining more often than females (75 per cent vs. 54 per cent, respectively). There was no correlation between MMP-2 positivity and Clark level or Breslow classification. A distinct group with unfavourable prognosis was identified. The 10-year survival for MMP-2-positive male melanoma patients was 39 per cent as opposed to 79 per cent with the other melanoma patients (P < 0.05). In the hierarchic Cox regression model for survival, MMP-2 immunoreactive protein was found to be independent of Clark level and Breslow classification. Overexpression of MMP-2 protein indicated a 4.5-fold relative risk of dying from melanoma. It is concluded that MMP-2 immunoreactive protein in melanoma cells is an independent prognostic factor for survival. High MMP-2 expression in male melanoma patients indicates an unfavourable prognosis.

The plasminogen activator system in women with polycystic ovary syndrome

OBJECTIVE

To evaluate the plasminogen activator system in women with polycystic ovary syndrome (PCOS).

DESIGN

Case-control study.

SETTING

A district general hospital in the United Kingdom.

PATIENT(S)

Eleven women with PCOS and 12 controls.

INTERVENTION(S)

Venipunctures for assays of the plasminogen activator system.

MAIN OUTCOME MEASURE(S)

Euglobulin clot lysis times, plasminogen activator inhibitor 1 (PAI-1) activity, fibrinogen, plasminogen, and alpha-2 antiplasmin concentrations in plasma.

RESULT(S)

Women with PCOS may had a significantly longer euglobulin clot lysis time (mean +/- SD, 389 +/- 164 minutes vs. 220 +/- 110 minutes), a higher PAI-1 activity (mean +/- SD, 19.7 +/- 12 arbitrary units (AU) per mL vs. 10.9 +/- 7.9 AU/mL), and a higher fibrinogen level (mean +/- SD, 4.02 +/- 0.64 g/L vs. 3.15 +/- 0.6 g/L) compared to controls.

CONCLUSION(S)

Women with the PCOS may have an imbalance in the plasminogen activator system that is tilted toward a reduced production of the proteolytic enzyme plasmin. Systemically, this may increase their risk of cardiovascular disease, but at cellular level in the ovaries, it may result in impaired follicular rupture and anovulation.