Modulation of small leucine-rich proteoglycans (SLRPs) expression in the mouse uterus by estradiol and progesterone

Lumican, a Multifunctional Cell Instructive Biomarker Proteoglycan Has Novel Roles as a Marker of the Hypercoagulative State of Long Covid Disease

This study has reviewed the many roles of lumican as a biomarker of tissue pathology in health and disease. Lumican is a structure regulatory proteoglycan of collagen-rich tissues, with cell instructive properties through interactions with a number of cell surface receptors in tissue repair, thereby regulating cell proliferation, differentiation, inflammation and the innate and humoral immune systems to combat infection. The exponential increase in publications in the last decade dealing with lumican testify to its role as a pleiotropic biomarker regulatory protein. Recent findings show lumican has novel roles as a biomarker of the hypercoagulative state that occurs in SARS CoV-2 infections; thus, it may also prove useful in the delineation of the complex tissue changes that characterize COVID-19 disease. Lumican may be useful as a prognostic and diagnostic biomarker of long COVID disease and its sequelae.

Involvement of small leucine-rich proteoglycans and telocytes in thin and thick human endometrium: immunohistochemical and ultrastructural examination

Thin endometrium, defined as an endometrial thickness of less than 7 mm during the late follicular phase, is a common cause of frequent cancelation of embryo transfers or recurrent implantation failure during assisted reproductive treatment. Small proteoglycans regulate intracellular signaling cascades by bridging other matrix molecules and tissue elements, affecting cell proliferation, adhesion, migration, and cytokine concentration. The aim of the study is to investigate the role of small leucine-rich proteoglycans in the pathogenesis of thin and thick human endometrium and their differences from normal endometrium in terms of fine structure properties. Normal, thin, and thick endometrial samples were collected, and small leucine-rich proteoglycans (SLRPs), decorin, lumican, biglycan, and fibromodulin immunoreactivities were comparatively analyzed immunohistochemically. The data were compared statistically. Moreover, ultrastructural differences among the groups were evaluated by transmission electron microscopy. The immunoreactivities of decorin, lumican, and biglycan were higher in the thin endometrial glandular epithelium and stroma compared to the normal and thick endometrium (p < .001). Fibromodulin immunoreactivity was also higher in the thin endometrial glandular epithelium than in the normal and thick endometrium (p < .001). However, there was no statistical difference in the stroma among the groups. Ultrastructural features were not profoundly different among cases. Telocytes, however, were not seen in the thin endometrium in contrast to normal and thin endometrial tissues. These findings suggest a possible role of changes in proteoglycan levels in the pathogenesis of thin endometrium.

Hyperprolactinemia modifies extracellular matrix components associated with collagen fibrillogenesis in harderian glands of non- and pregnant female mice

The harderian gland (HG) is a gland located at the base of the nictating membrane and fills the inferomedial aspect of the orbit in rodents. It is under the influence of the hypothalamic-pituitary-gonadal axis and, because of its hormone receptors, it is a target tissue for prolactin (PRL) and sex steroid hormones (estrogen and progesterone). In humans and murine, the anterior surface of the eyes is protected by a tear film synthesized by glands associated with the eye. In order to understand the endocrine changes caused by hyperprolactinemia in the glands responsible for the formation of the tear film, we used an animal model with metoclopramide-induced hyperprolactinemia (HPRL). Given the evidences that HPRL can lead to a process of cell death and tissue fibrosis, the protein expression of small leucine-rich proteoglycans (SLRPs) was analyzed through immunohistochemistry in the HG of the non- and the pregnant female mice with hyperprolactinemia. The SRLPs are related to collagen fibrillogenesis and they participate in pro-apoptotic signals. Our data revealed that high prolactin levels and changes in steroid hormones (estrogen and progesterone) can lead to an alteration in the amount of collagen, and in the structure of type I and III collagen fibers through changes in the amounts of lumican and decorin, which are responsible for collagen fibrillogenesis. This fact can lead to the impaired functioning of the HG by excessive apoptosis in the HG of the non- and the pregnant female mice with HPRL and especially in the HG of pregnancy-associated hyperprolactinemia.

Single-cell analysis of menstrual endometrial tissues defines phenotypes associated with endometriosis

BACKGROUND

Endometriosis is a common, complex disorder which is underrecognized and subject to prolonged delays in diagnosis. It is accompanied by significant changes in the eutopic endometrial lining.

METHODS

We have undertaken the first single-cell RNA-sequencing (scRNA-Seq) comparison of endometrial tissues in freshly collected menstrual effluent (ME) from 33 subjects, including confirmed endometriosis patients (cases) and controls as well as symptomatic subjects (who have chronic symptoms suggestive of endometriosis but have not been diagnosed).

RESULTS

We identify a unique subcluster of proliferating uterine natural killer (uNK) cells in ME-tissues from controls that is almost absent from endometriosis cases, along with a striking reduction of total uNK cells in the ME of cases (p < 10^-16). In addition, an IGFBP1+ decidualized subset of endometrial stromal cells are abundant in the shed endometrium of controls when compared to cases (p < 10^-16) confirming findings of compromised decidualization of cultured stromal cells from cases. By contrast, endometrial stromal cells from cases are enriched in cells expressing pro-inflammatory and senescent phenotypes. An enrichment of B cells in the cases (p = 5.8 × 10^-6) raises the possibility that some may have chronic endometritis, a disorder which predisposes to endometriosis.

CONCLUSIONS

We propose that characterization of endometrial tissues in ME will provide an effective screening tool for identifying endometriosis in patients with chronic symptoms suggestive of this disorder. This constitutes a major advance, since delayed diagnosis for many years is a major clinical problem in the evaluation of these patients. Comprehensive analysis of ME is expected to lead to new diagnostic and therapeutic approaches to endometriosis and other associated reproductive disorders such as female infertility.

Novel regulatory roles of small leucine-rich proteoglycans in remodeling of the uterine cervix in pregnancy

The cervix undergoes rapid and dramatic shifts in collagen and elastic fiber structure to achieve its disparate physiological roles of competence during pregnancy and compliance during birth. An understanding of the structure-function relationships of collagen and elastic fibers to maintain extracellular matrix (ECM) homeostasis requires an understanding of the mechanisms executed by non-structural ECM molecules. Small-leucine rich proteoglycans (SLRPs) play key functions in biology by affecting collagen fibrillogenesis and regulating enzyme and growth factor bioactivities. In the current study, we evaluated collagen and elastic fiber structure-function relationships in mouse cervices using mice with genetic ablation of decorin and/or biglycan genes as representative of Class I SLRPs, and lumican gene representative of Class II SLRP. We identified structural defects in collagen fibril and elastic fiber organization in nonpregnant mice lacking decorin, or biglycan or lumican with variable resolution of defects noted during pregnancy. The severity of collagen and elastic fiber defects was greater in nonpregnant mice lacking both decorin and biglycan and defects were maintained throughout pregnancy. Loss of biglycan alone reduced tissue extensibility in nonpregnant mice while loss of both decorin and biglycan manifested in decreased rupture stretch in late pregnancy. Collagen cross-link density was similar in the Class I SLRP null mice as compared to wild-type nonpregnant and pregnant controls. A broader range in collagen fibril diameter along with an increase in mean fibril spacing was observed in the mutant mice compared to wild-type controls. Collectively, these findings uncover functional redundancy and hierarchical roles of Class I and Class II SLRPs as key regulators of cervical ECM remodeling in pregnancy. These results expand our understating of the critical role SLRPs play to maintain ECM homeostasis in the cervix.

Roles of Two Small Leucine-Rich Proteoglycans Decorin and Biglycan in Pregnancy and Pregnancy-Associated Diseases

Two small leucine-rich proteoglycans (SLRP), decorin and biglycan, play important roles in structural–functional integrity of the placenta and fetal membranes, and their alterations can result in several pregnancy-associated diseases. In this review, we briefly discuss normal placental structure and functions, define and classify SLRPs, and then focus on two SLRPs, decorin (DCN) and biglycan (BGN). We discuss the consequences of deletions/mutations of DCN and BGN. We then summarize DCN and BGN expression in the pregnant uterus, myometrium, decidua, placenta, and fetal membranes. Actions of these SLRPs as ligands are then discussed in the context of multiple binding partners in the extracellular matrix and cell surface (receptors), as well as their alterations in pathological pregnancies, such as preeclampsia, fetal growth restriction, and preterm premature rupture of membranes. Lastly, we raise some unanswered questions as food for thought.

The influence of progesterone and prostaglandin F2α on decorin and the adhesion of caruncular epithelial cells of bovine placenta at early-mid pregnancy-Part II

One of the most important processes determining the proper course of gestation and its physiological termination in cows is the adhesion of epithelial cells allowing for direct contact of maternal and foetal parts of the placenta. Throughout pregnancy, placental cells are under strict hormonal control, which among others regulates the concentration and activity of specific proteins participating in the extracellular matrix remodelling of foetal membranes. The aim of the study was to evaluate the influence of progesterone and prostaglandin F_2α on the adhesion of epithelial cells at early-mid pregnancy in cows. Additionally, the impact of selected hormones on anti-adhesive properties of decorin was evaluated. Caruncular epithelial cells were isolated from healthy cows during pregnancy, immediately after slaughter. Primary cell cultures derived from the 2nd and 4th month of gestation were used in the experiments. The viability of cells was assessed by MTT assay. The adhesion of cells to fibronectin was measured spectrophotometrically. The activity of metalloproteinases was confirmed by the metalloproteinase assay. Progesterone (10^-5 and 10^-7  mol/L) and prostaglandin F_2α (10^-4 _, 10^-5 and 10^-7  mol/L) increased the viability of bovine caruncular epithelial cells in the 2nd month of pregnancy. The treatment with prostaglandin F_2α significantly reduced the number of adherent cells from the 2nd month of gestation at the doses of 10^-4 and 10^-5  mol/L. Both progesterone and prostaglandin F_2α were shown to have an effect of decorin resulting in both a decrease in metalloproteinase activity and an increase in adhesion of cells to fibronectin.

lncRNA FDNCR promotes apoptosis of granulosa cells by targeting the miR-543-3p/DCN/TGF-β signaling pathway in Hu sheep

Long non-coding RNAs (lncRNAs) regulate the development of follicles and reproductive diseases, but the mechanisms by which lncRNAs regulate ovarian functions and fertility remain elusive. We profiled the expression of lncRNAs in ovarian tissues of Hu sheep with different prolificacy and identified 21,327 lncRNAs. Many of the lncRNAs were differentially expressed in different groups. We further characterized an lncRNA that was predominantly expressed in the ovaries of the low prolificacy Fec^B+ (LPB+) group and mainly present in granulosa cells (GCs), and the expression of this lncRNA decreased during follicular development, which we named follicular development-associated lncRNA (FDNCR). Next, we found that FDNCR directly binds miR-543-3p, and decorin (DCN) was identified as a target of miR-543-3p. FDNCR overexpression promoted GC apoptosis through increased expression of DCN, which could be attenuated by miR-543-3p. Furthermore, miR-543-3p increased and FDNCR reduced the expression of transforming growth factor-β (TGF-β) pathway-related genes, including TGF-β1 and inhibin beta A (INHBA), which were upregulated upon DCN silencing. Our results demonstrated that FDNCR sponges miR-543-3p in GCs and prevents miR-543-3p from binding to the DCN 3′ UTR, resulting in DCN transactivation and TGF-β pathway inhibition and promotion of GC apoptosis in Hu sheep. These findings provide insights into the mechanisms underlying prolificacy in sheep.

Proteomics Complementation of the Rat Uterotrophic Assay for Estrogenic Endocrine Disruptors: A Roadmap of Advancing High Resolution Mass Spectrometry-Based Shotgun Survey to Targeted Biomarker Quantifications

The widely used rat uterotrophic assay to assess known and potential estrogenic compounds only considers uterine weight gain as endpoint measurement. To complement this method with an advanced technology that reveals molecular targets, we analyzed changes in protein expression using label-free quantitative proteomics by nanoflow liquid chromatography coupled with high-resolution mass spectrometry and tandem mass spectrometry from uterine protein extracts of ovariectomized rats after daily 17β-estradiol exposure for five days in comparison with those of vehicle-treated control animals. Our discovery-driven study revealed 165 uterine proteins significantly regulated by estrogen treatment and mapped by pathway analyses. Estrogen-regulated proteins represented cell death, survival and development, cellular growth and proliferation, and protein synthesis as top molecular and cellular functions, and a network found with the presence of nuclear estrogen receptor(s) as a prominent molecular node confirmed the relevance of our findings to hormone-associated events. An exploratory application of targeted proteomics to bisphenol A as a well-known example of an estrogenic endocrine disruptor is also presented. Overall, the results of this study have demonstrated the power of combining untargeted and targeted quantitative proteomic strategies to identify and verify candidate molecular markers for the evaluation of endocrine-disrupting chemicals to complement a conventional bioassay.

Clomiphene citrate impairs the endometrial CD98 expression in ovariectomized and non-ovariectomized rats: Role of HCG

Background

Clomiphene citrate (CC) is one of the widely used drugs as an ovulation stimulant, but its adverse effects on the endometrium results in lowering down the pregnancy rate. Endometrium CD98 is also important in the process of implantation.

Objective

To evaluate the immunohistochemistry expression levels of endometrial CD98 following injection of CC with and without Human chorionic gonadotropin (HCG) in ovariectomized and non-ovariectomized rats.

Materials and Methods

Seventy two (12-14 wk old) female Wistar rats were randomly divided into two groups (n = 36): (a) ovariectomized and (b) non-ovariectomized. Each group was further divided into six subgroups (n = 6/each): (1) CC 10 mg/kg, (2) CC 20 mg/kg, (3) HCG, (4) CC 10 mg/kg with HCG, (5) CC 20 mg/kg with HCG, and (6) control. The experimental subgroups received a single dose of CC (daily, five days) and HCG (after the last injection of CC) alone or in combination. Immunohistochemistry staining was performed on paraffin-embedded endometrial tissues to evaluate the expression levels of CD98.

Results

Animals undergoing ovariectomy presented a significantly lower expression level of endometrial CD98 (p < 0.001) when compared with non-ovariectomized in the same condition that groups were subdivided. There was also a dose-dependent reduction (p < 0.001) in the expression of CD98 in non-ovariectomized subgroups when compared with control group. In addition, injection of HCG following treatment with CC improved its expression.

Conclusion

It was concluded that CC impairs CD98 expression in endometrium and this impairment is intensified with the removal of the ovary. Also, an injection of HCG following treatment with CC can slightly improve the expression of CD98.

Knockdown of Lumican Inhibits Proliferation and Migration of Bladder Cancer

Lumican (LUM) is differentially expressed between normal and cancer tissues. The purpose of this study was to investigate the role of LUM in the proliferation and migration of bladder cancer (BCa) cells. Our study included 97 cases of BCa diagnosis from our hospital between June 2013 and June 2016. The expression of LUM was analyzed by immunohistochemistry and Western blot. To characterize the function of LUM, BCa cells were stably infected with a lentivirus against LUM, and cell proliferation, migration and cell cycle were investigated. In addition, xenograft experiments were performed in nude mice to evaluate the role of LUM in BCa. Our results showed that LUM was overexpressed in BCa tissues and cell lines in comparison to normal tissues. LUM expression was related to pathological type, T stage and N stage (P < .05). In addition, depletion of LUM inhibited the proliferation and migration of BCa cells by inactivating MAPK signaling. In conclusion, LUM promotes the proliferation and migration of BCa cells and may serve as a potential therapeutic target for BCa.

Increased Expression of NDRG3 in Mouse Uterus During Embryo Implantation and in Mouse Endometrial Stromal Cells During In Vitro Decidualization

Decidualization is an indispensable event in the embryo implantation process, but its underlying molecular mechanisms remain elusive. In this study, we showed that in mice, the uterine expression of N-myc downstream-regulated gene 3 (NDRG3), a member of the α/β hydrolase superfamily, was induced by estradiol and progesterone. During the embryo implantation process, uterine Ndrg3 expression was remarkably upregulated, and its expression level at implantation sites (IS) was significantly higher than that at inter-IS. Increased uterine expression of Ndrg3 was associated with artificial decidualization and the activation of delayed implantation. The in vitro decidualization of mouse endometrial stromal cells (ESCs) induced by estradiol and progesterone was also accompanied by increased Ndrg3 expression, and downregulated Ndrg3 expression in ESCs effectively inhibited decidualization. miR-290b-5p was identified as an upstream regulator of Ndrg3, and the uterine expression level of miR-290b-5p was decreased during the implantation process. Furthermore, overexpression of miR-290b-5p in mouse ESCs inhibited their in vitro decidualization. Taken together, these data suggested that Ndrg3 might play an important role in embryo implantation by regulating decidualization potentially via the estrogen/progesterone/miR-290b-5p pathway.

Small leucine-rich proteoglycans (SLRPs) in the endometrium of polycystic ovary syndrome women: a pilot study

Background

Small leucine-rich proteoglycans (SLRPs) play an important role in tissue homeostasis and cell proliferation since these proteoglycans sequester multiple growth factors. However, the content of SLRPs in the endometrium of polycystic ovary syndrome (PCOS) women is unknown. Our purpose was to test the hypothesis that excessive endometrial proliferation in PCOS may be partly related to abnormalities in SLRPs.

Methods

In a cross section study a total of 20 endometrial samples were collected from 10 patients with PCOS and 10 ovulatory women during their proliferative (pre-ovulatory) phase. The study subjects were matched for age, body mass index and race. The age range was 20 to 35 years. All volunteers were evaluated in reproductive endocrinology clinic, Gynecology Division, Clinics Hospital, University of São Paulo Medical School Profile and concentration of small leucine-rich proteoglycans (decorin, lumican, fibromodulin and biglycan) were determined by immunohistochemical testing and Western blotting.

Results

Decorin and lumican demonstrated higher immunoreactivity and relative expression in the endometrium of women with PCOS compared to that of women with regular menstrual cycles.

Conclusion

Our data suggests that the endometrium of PCOS women demonstrate a greater content of SLRP than controls; decorin and lumican, in particular, were found in higher concentrations in the endometrium of PCOS women during the proliferative phase. These differences may, in part, explain the excess of endometrial proliferation frequently observed in PCOS. Further studies are warranted.

Mapping of estradiol binding sites through receptor micro-autoradiography in the endometrial stroma of early pregnant mice

Estradiol triggers key biological responses in the endometrium, which rely on the presence and levels of its cognate receptors on target cells. Employing the receptor micro-autoradiography (RMAR) technique, we aimed to provide a temporal and spatial map of the functional binding sites for estradiol in the mouse endometrial stroma during early pregnancy. Uterine samples from days 1.5 to 7.5 of pregnancy were collected 1 h after tritiated- (3H-) estradiol administration and prepared for RMAR analysis. Autoradiographic incorporation of 3H-thymidine (after 1-h pulse) was evaluated over the same gestational interval. Combined RMAR with either histochemistry with Dolichus biflorus (DBA) lectin or immunohistochemistry for detection of the desmin further characterized 3H-estradiol binding pattern in uterine Natural Killer (uNK) and decidual cells, respectively. 3H-estradiol binding levels oscillated in the pregnant endometrial stroma between the mesometrial and antimesometrial regions as well as the superficial and deep domains. Although most of the endometrial stromal cells retained the hormone, a sub-population of them, as well as endothelial and uNK cells, were unable to do so. Rises in the levels of 3H-estradiol binding preceded endometrial stromal cell proliferation. 3H-estradiol binding and 3H-thymidine incorporation progressively decreased along the development of the antimesometrial decidua. Endothelial proliferation occurred regardless of 3H-estradiol binding, whereas pericytes proliferation was associated with high levels of hormone binding. Endometrial cell populations autonomously control their levels of 3H-estradiol binding and retention, a process associated with their proliferative competence. Collectively, our results illustrate the intricate regulatory dynamic of nuclear estrogen receptors in the pregnant mouse endometrium.

Extracellular matrix proteins in healthy and retained placentas, comparing hemochorial and synepitheliochorial placentas

The placenta expresses structural and biologically active proteins. Their synthesis is mainly regulated by genomic or nongenomic signals and modulated by hormones. These protein profiles are altered during different stages of pregnancy. The biological properties of extracellular matrix (ECM) proteins were defined and described in a number of tissues including placenta. These properties enable them to be the main players in the processes of attachment or invasion into the endometrium during initial placenta formation and its timely separation after delivery and detachment. In this review, we focused on the role of ECM proteins during attachment of the placenta to the uterine wall, its timely separation, and the implications of this process on retained or pathologically attached placenta. Although the amount of published information in this area is relatively scant, some of the key proteins and processes are well defined. We focused on the available data detailing the ECM protein profiles of human (histologically thin; hemochorial) and bovine (histologically thick; epitheliochorial) placentas and compared the shared and unique ECM proteins that are relevant to placental attachment and separation.

Sterile inflammation as a factor in human male infertility: Involvement of Toll like receptor 2, biglycan and peritubular cells

Changes in the wall of seminiferous tubules in men with impaired spermatogenesis imply sterile inflammation of the testis. We tested the hypothesis that the cells forming the wall of seminiferous tubules, human testicular peritubular cells (HTPCs), orchestrate inflammatory events and that Toll like receptors (TLRs) and danger signals from the extracellular matrix (ECM) of this wall are involved. In cultured HTPCs we detected TLRs, including TLR2. A TLR-2 ligand (PAM) augmented interleukin 6 (IL-6), monocyte chemo-attractant protein-1 (MCP-1) and pentraxin 3 (PTX3) in HTPCs. The ECM-derived proteoglycan biglycan (BGN) is secreted by HTPCs and may be a TLR2-ligand at HTPCs. In support, recombinant human BGN increased PTX3, MCP-1 and IL-6 in HTPCs. Variable endogenous BGN levels in HTPCs derived from different men and differences in BGN levels in the tubular wall in infertile men were observed. In testes of a systemic mouse model for male infertility, testicular sterile inflammation and elevated estradiol (E2) levels, BGN was also elevated. Hence we studied the role of E2 in HTPCs and observed that E2 elevated the levels of BGN. The anti-estrogen ICI 182,780 blocked this action. We conclude that TLR2 and BGN contribute to sterile inflammation and infertility in man.

Molecular cloning, expression analysis, and function of decorin in goat ovarian granulosa cells

Decorin (DCN), a component of the extracellular matrix (ECM), participates in ECM assembly and influences cell proliferation and apoptosis in many mammalian tissues and cells. However, expression and function of DCN in the ovary remain unclear. This study cloned the full-length cDNA of goat DCN obtained from the ovary of an adult goat. Sequence analysis revealed that the putative DCN protein shared a highly conserved amino acid sequence with known mammalian homologs. The tissue distribution of DCN mRNA expression was evaluated by real-time PCR, and the results showed that DCN was widely expressed in the tissues of adult goat. Immunohistochemistry results suggested that DCN protein existed in the granulosa cells and oocytes from all types of follicles and theca cells of antral follicles. Moreover, hCG-induced DCN mRNA expression was significantly reduced by the inhibitors of protein kinase A, PI3K, or p38 kinase (P < 0.05), which are key mediators involved in hCG-induced DCN expression. Overexpression of DCN significantly increased apoptosis and blocked cell cycle progression in cultured granulosa cells (P < 0.05). Western blot analysis also showed that overexpression of DCN upregulated the expression levels of p21 protein (P < 0.05), whereas no effects were observed on the expression of Bax and Bcl-2 and on Bcl-2/Bax ratio (P > 0.05). These findings suggested that DCN regulates the apoptosis and cell cycle of granulosa cells.

Concentration of glycosaminoglycan in ovariectomized mice uterus after treatment with ovarian steroids

The aim of this study was to evaluate the amount of non- and sulfated glycosaminoglycans in the ovariectomized mice uterus, after treatment with ovarian steroids. For this purpose, 50 adult female mice were divided into five groups with 10 animals/each: control group: CG (ovary intact), and ovariectomized groups: OG (vehicle), EG (estradiol), PG (progesterone) and EPG (estradiol combined to progesterone). The treatments started 30 days after ovariectomy. All the animals were treated for 50 consecutive days. These hormones were administered in a sterile oily solution via gavage. Twenty-four hours after the last treatment, all animals were euthanized, removing the uterine horn for biochemical analyses. To quantify, the hyaluronic acid (HA) used ELISA-like fluorometric assay, and the sulfated glycosaminoglycans (GAGs) used agarose gel electrophoresis. The amount of HA was significantly higher in the group treated with progesterone (PG) compared to the others groups (p < 0.05), and in the group treated with estradiol (EG), the amount of chondroitin/dermatan sulfate was significantly higher compared to the others groups (p < 0.05), and in the group treated with progesterone (PG), the amount of heparan sulfate was significantly lower compared to the others groups, except to control group (p < 0.05). Our results showed that the estroprogestative therapy after long time (50 days) profoundly affected the amount of glycosaminoglycans in uterine. These changes may be indicative of uterine pathology such as the development of tumor.

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

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

Gonadotropin-releasing hormone analogues inhibit leiomyoma extracellular matrix despite presence of gonadal hormones

OBJECTIVE

To determine the effect of GnRH analogues (GnRH-a) leuprolide acetate (LA) and cetrorelix acetate on gonadal hormone-regulated expression of extracellular matrix in uterine leiomyoma three-dimensional (3D) cultures.

DESIGN

Laboratory study.

SETTING

University research laboratory.

PATIENT(S)

Women undergoing hysterectomy for symptomatic leiomyomas.

INTERVENTION(S)

The 3D cell cultures, protein analysis, Western blot, immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Expression of extracellular matrix proteins, collagen 1, fibronectin, and versican in leiomyoma cells 3D cultures exposed to E2, P, LA, cetrorelix acetate, and combinations for 24- and 72-hour time points.

RESULT(S)

The 3D leiomyoma cultures exposed to E2 for 24 hours demonstrated an increased expression of collagen-1 and fibronectin, which was maintained for up to 72 hours, a time point at which versican was up-regulated significantly. Although P up-regulated collagen-1 protein (1.29 ± 0.04) within 24 hours of exposure, significant increase in all extracellular matrix (ECM) proteins was observed when the gonadal hormones were used concomitantly. Significant decrease in the amount of ECM proteins was observed on use of GnRH-a, LA and cetrorelix, with 24-hour exposure. Both the compounds also significantly decreased ECM protein concentration despite the presence of E2 or both gonadal hormones.

CONCLUSION(S)

This study demonstrates that GnRH-a directly affect the gonadal hormone-regulated collagen-1, fibronectin, and versican production in their presence. These findings suggest that localized therapy with GnRH-a may inhibit leiomyoma growth even in the presence of endogenous gonadal hormone exposure, thereby providing a mechanism to eliminate the hypoestrogenic side effects associated with GnRH-a therapy.

The absence of the embryo in the pseudopregnant uterus alters the deposition of some ECM molecules during decidualization in mice

The embryo-implantation promotes deep changes in the uterus resulting in the formation of a new structure at the maternal-fetal interface, the decidua. Decidualization can also be induced in pseudopregnant rodents resulting in a structure called deciduoma that is morphologically and functionally similar to the decidua. Previous studies from our and other laboratories demonstrate that in rodents, decidualization of the endometrium requires remarkable remodeling of the endometrial extracellular matrix (ECM) that is mainly coordinated by estradiol and progesterone. The influence of the embryo in this process, however, has not yet been investigated. To enlarge the knowledge on this subject, the present study investigates the behavior of a set of ECM molecules, in the absence of paracrine cues originated from the embryo. For that deciduoma was induced in pseudopregnant Swiss mice, and the distribution of collagen types I, III, IV, V and the proteoglycans decorin and biglycan was investigated by immunolabeling from the fifth to the eighth day of pseudopregnancy. It was observed the deposition of collagen types III and IV as well as decorin and biglycan was similar to that previously described by our group in the decidua. However, in the absence of the embryo, some differences occur in the distribution of collagen types I and V, suggesting that beside the major role of ovarian hormones on the endometrial ECM remodeling, molecular signals originated from the conceptus may influence this process.

Uterine NDRG2 expression is increased at implantation sites during early pregnancy in mice, and its down-regulation inhibits decidualization of mouse endometrial stromal cells

BACKGROUND

N-myc down-regulated gene 2 (NDRG2) is a tumor suppressor involved in cell proliferation and differentiation. The aim of this study was to determine the uterine expression pattern of this gene during early pregnancy in mice.

METHODS

Uterine NDRG2 mRNA and protein expression levels were determined by RT-PCR and Western blot analyses, respectively, during the peri-implantation period in mice. Immunohistochemical (IHC) analysis was performed to examine the spatial localization of NDRG2 expression in mouse uterine tissues. The in vitro decidualization model of mouse endometrial stromal cells (ESCs) was used to evaluate decidualization of ESCs following NDRG2 knock down by small interfering RNA (siRNA). Statistical significance was analyzed by one-way ANOVA using SPSS 19.0 software.

RESULTS

Uterine NDRG2 gene expression was significantly up-regulated and was predominantly localized to the secondary decidual zone on days 5 and 8 of pregnancy in mice. Its increased expression was associated with artificial decidualization as well as the activation of delayed implantation. Furthermore, uterine NDRG2 expression was induced by estrogen and progesterone treatments. The in vitro decidualization of mouse ESCs was accompanied by up-regulation of NDRG2 expression, and knock down of its expression in these cells by siRNA inhibited the decidualization process.

CONCLUSIONS

These results suggest that NDRG2 might play an important role in the process of decidualization during early pregnancy.

Decorin induced by progesterone plays a crucial role in suppressing endometriosis

Dienogest, a synthetic progestin, has been shown to be effective against endometriosis, although it is still unclear as to how it affects the ectopic endometrial cells. Decorin has been shown to be a powerful endogenous tumor repressor acting in a paracrine fashion to limit tumor growth. Our objectives were to examine the direct effects of progesterone and dienogest on the in vitro proliferation of the human ectopic endometrial epithelial and stromal cell lines, and evaluate as to how decorin contributes to this effect. We also examined DCN mRNA expression in 50 endometriosis patients. The growth of both cell lines was inhibited in a dose-dependent manner by both decorin and dienogest. Using a chromatin immunoprecipitation assay, it was noted that progesterone and dienogest directly induced the binding of the decorin promoter in the EMOsis cc/TERT cells (immortalized human ovarian epithelial cells) and CRL-4003 cells (immortalized human endometrial stromal cells). Progesterone and dienogest also led to significant induced cell cycle arrest via decorin by promoting production of p21 in both cell lines in a dose-dependent manner. Decorin also suppressed the expression of MET in both cell lines. We confirmed that DCN mRNA expression in patients treated with dienogest was higher than that in the control group. In conclusion, decorin induced by dienogest appears to play a crucial role in suppressing endometriosis by exerting anti-proliferative effects and inducing cell cycle arrest via the production of p21 human ectopic endometrial cells and eutopic endometrial stromal cells.

Genes encoding proteoglycans are associated with the risk of anterior cruciate ligament ruptures

BACKGROUND

Genetic variants within genes involved in fibrillogenesis have previously been implicated in anterior cruciate ligament (ACL) injury susceptibility. Proteoglycans also have important functions in fibrillogenesis and maintaining the structural integrity of ligaments. Genes encoding proteoglycans are plausible candidates to be investigated for associations with ACL injury susceptibility; polymorphisms within genes encoding the proteoglycans aggrecan (ACAN), biglycan (BGN), decorin (DCN), fibromodulin (FMOD) and lumican (LUM) were examined.

METHODS

A case-control genetic association study was conducted. 227 participants with surgically diagnosed ACL ruptures (ACL group) and 234 controls without any history of ACL injury were genotyped for 10 polymorphisms in 5 proteoglycan genes. Inferred haplotypes were constructed for specific regions.

RESULTS

The G allele of ACAN rs1516797 was significantly under-represented in the controls (p=0.024; OR=0.72; 95% CI 0.55 to 0.96) compared with the ACL group. For DCN rs516115, the GG genotype was significantly over-represented in female controls (p=0.015; OR=9.231; 95%CI 1.16 to 73.01) compared with the ACL group and the AA genotype was significantly under-represented in controls (p=0.013; OR=0.33; 95% CI 0.14 to 0.78) compared with the female non-contact ACL injury subgroup. Haplotype analyses implicated regions overlapping ACAN (rs2351491 C>T-rs1042631 T>C-rs1516797 T>G), BGN (rs1126499 C>T-rs1042103 G>A) and LUM-DCN (rs2268578 T>C-rs13312816 A>T-rs516115 A>G) in ACL injury susceptibility.

CONCLUSIONS

These independent associations and haplotype analyses suggest that regions within ACAN, BGN, DCN and a region spanning LUM-DCN are associated with ACL injury susceptibility. Taking into account the functions of these genes, it is reasonable to propose that genetic sequence variability within the genes encoding proteoglycans may potentially modulate the ligament fibril properties.

Estradiol induces transcriptional and posttranscriptional modifications in versican expression in the mouse uterus

We have previously shown the differential expression of versican in the mouse uterus under ovarian hormone influence. We also demonstrated there is not a direct correlation between mRNA levels and protein expression, suggesting posttranscriptional events, such as alteration in mRNA stability. This posttranscriptional effect may result in the elongation and stabilization of transcripts poly(A) tail. Thus, the aim of this study was to analyze whether estradiol (E2) regulates versican mRNA stability and expression in a dose-related and time-dependent manner. For this purpose female mice were ovariectomized and treated with a single injection of 0.1 or 10 μg E2. To block transcription a group of females received a single injection of alpha-amanitin before hormone administration. Uterine tissues were collected 30 min, 1, 3, 6, 12 and 24 h after treatments and processed for quantitative real time PCR (qPCR), RACE-PAT Assay and immunohistochemistry. qPCR showed that versican mRNA levels are higher than control from 3 to 24 h after E2 administration, whereas after transcription inhibition versican mRNA unexpectedly increases within 3 h, which can be explained when transcriptional blockers alter the degradation rate of the transcript, resulting in the superinduction of this mRNA. Accordingly, analysis of versican transcript poly(A) tail evidenced a longer product 3 h after treatment, but not after 12 h. Versican immunoreaction becomes conspicuous in the superficial stroma only 3 h after E2 injection, whereas the whole stroma is immunoreactive from 6 h onward. These results demonstrate that E2 modulates versican at the transcriptional and posttranscriptional levels in a time-dependent manner.