TGF-β Induces Endometriotic Progression via a Noncanonical, KLF11-Mediated Mechanism

miR-10a-5p Regulates the Proliferation and Differentiation of Porcine Preadipocytes Targeting the KLF11 Gene

In the swine industry, meat quality, color, and texture are influenced by the excessive differentiation of fat cells. miRNAs have emerged as integral regulators of adipose development. This study delves into the influence of miR-10a-5b on the proliferation and differentiation of pig preadipocytes. Our findings reveal that miR-10a-5b is prevalent across various tissues. It hinders preadipocyte proliferation, amplifies the expression of adipogenic genes, promotes lipid accumulation, and, as a result, advances preadipocyte differentiation. We predict that KLF11 is the target gene of miRNA. A dual-fluorescence reporter assay was conducted to validate the binding sites of miR-10a-5b on the 3'UTR of the KLF11 mRNA. Results showed that miR-10a-5b targeted KLF11 3'UTR and reduced the fluorescence activity of the dual-fluorescent reporter vector. Our research also indicates that miR-10a-5b targets and downregulates the expression of both mRNA and the protein levels of KLF11. During the differentiation of the preadipocytes, KLF11 inhibited adipose differentiation and was able to suppress the promotion of adipose differentiation by miR-10a-5b. This underscores miR-10a-5b's potential as a significant regulator of preadipocyte behavior by modulating KLF11 expression, offering insights into the role of functional miRNAs in fat deposition.

The Impact of Histone Modifications in Endometriosis Highlights New Therapeutic Opportunities

Endometriosis is a chronic disorder of the female reproductive system which afflicts a great number of women worldwide. Histone deacetylases (HDACs) prevent the relaxation of chromatin, thereby positively or negatively modulating gene transcription. The current review aims at studying the impact of histone modifications and their therapeutic targeting in endometriosis. In order to identify relevant studies, a literature review was conducted using the MEDLINE and LIVIVO databases. The current manuscript represents the most comprehensive, up-to-date review of the literature focusing on the particular role of HDACs and their inhibitors in the context of endometriosis. HDAC1, HDAC2, HDAC3, Sirtuin 1, and Sirtuin 3, are the five most studied HDAC enzymes which seem to, at least partly, influence the pathophysiology of endometriosis. Both well-established and novel HDACIs could possibly represent modern, efficacious anti-endometriotic drug agents. Altogether, histone modifications and their therapeutic targeting have been proven to have a strong impact on endometriosis.

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.

Network pharmacology and experimental validation to explore the potential mechanism of Sanjie Zhentong Capsule in endometriosis treatment

PURPOSE

Sanjie Zhentong Capsule (SZC) is gradually becoming widely used in the treatment of endometriosis (EMs) and has demonstrated an excellent curative effect in the clinic. However, the active components and mechanisms of Sanjie Zhentong Capsule (SZC) in the treatment of endometriosis (EMs) remain unclear, and further research is needed to explore the effects of Sanjie Zhentong Capsule (SZC).

MATERIALS AND METHODS

First, a drug target database of Sanjie Zhentong capsule (SZC) was established by consulting the TCMSP database and related literature. An endometriosis (EMs) disease target database was then established by consulting the GeneCards, OMIM and Drug Bank databases. The overlapping genes of SZC and EMs were determined, and protein-protein interactions (PPIs), gene ontology (GO) and Kyoto Gene and Genome Encyclopedia (KEGG) analyses were performed to predict the potential therapeutic mechanisms. Molecular docking was used to observe whether the key active ingredients and targets predicted by network pharmacology had good binding energy. Finally, in vitro experiments such as CCK-8, flow cytometry and RT-PCR assays were carried out to preliminarily verify the potential mechanisms.

RESULTS

Through the construction of a pharmacological network, we identified a total of 28 active components in SZC and 52 potential therapeutic targets. According to GO and KEGG enrichment analyses, the effects of SZC treatment may be related to oxidative stress, steroid metabolism, apoptosis and proliferation. We also experimentally confirmed that SZC can regulate the expression of steroid hormone biosynthesis-related genes, inhibit ectopic endometrial stromal cell (EESC) proliferation and oxidative stress, and promote apoptosis.

CONCLUSION

This study explored the potential mechanism of SZC in the treatment of EMs through network pharmacology and experiments, providing a basis for further future research on SZC in the treatment of EMs.

The effect of carbamazepine, which increases oestrogen destruction, on the endometriotic implants; an experimental rat model

We planned this experimental study to investigate the effect of carbamazepine (CMZ) on the endometriotic implants. Rats were randomised into four groups after endometriosis surgery. Drinking water was given to the sham group, 0.2 mg/kg oestradiol valerate (EV) to the EV group, 100 mg/kg/day CMZ to the CMZ group, and 0.2 mg/kg EV and 100 mg/kg/day CMZ to the EV-CMZ group. The endometrium of the rats using CMZ stained more intensely with cytochrome P450-3A4 (CYP3A4) enzyme. No endometrial hyperplasia was found in these rats. Endometriotic implants weight was found to be higher in these rats. There was no difference between the groups in terms of staining of the endometriotic implants with CYP3A4 enzyme. Endometriotic implants were less stained with the CYP3A4 enzyme than the endometrium. According to our results, CMZ does not increase the destruction of oestrogen in the endometriotic implants, unlike the endometrium. It may even cause the lesion to enlarge.Impact statementWhat is already known on this subject? Endometriosis is an oestrogen-dependent, progressive disease. Carbamazepine (CMZ) is known to increase oestrogen degradation by activating the cytochrome P450-3A4 (CYP3A4) enzyme. CMZ can be used in the treatment of endometriosis because it increases oestrogen breakdown in tissues.What do the results of this study add? CMZ can protect the endometrium against hyperplasia by increasing the amount of CYP3A4 enzyme in the endometrium. This effect could not be demonstrated in the endometriotic implants. The presence of CYP3A4 enzyme less in the endometriotic implants than in the endometrium may explain this situation. In addition, the fact that CMZ does not increase the enzyme in the endometriotic implants may contribute to this situation.What are the implications of these findings for clinical practice and/or further research? CMZ may not be a suitable alternative in the treatment of endometriosis. However, it may protect against endometrial hyperplasia. Clinical studies are needed for this effect.

KLF11 deficiency enhances chemokine generation and fibrosis in murine unilateral ureteral obstruction

Progression of virtually all forms of chronic kidney disease (CKD) is associated with activation of pro-inflammatory and pro-fibrotic signaling pathways. Despite extensive research, progress in identifying therapeutic targets to arrest or slow progression of CKD has been limited by incomplete understanding of basic mechanisms underlying renal inflammation and fibrosis in CKD. Recent studies have identified Kruppel-like transcription factors that have been shown to play critical roles in renal development, homeostasis, and response to injury. Although KLF11 deficiency has been shown to increase collagen production in vitro and tissue fibrosis in other organs, no previous study has linked KLF11 to the development of CKD. We sought to test the hypothesis that KLF11 deficiency promotes CKD through upregulation of pro-inflammatory and pro-fibrogenic signaling pathways in murine unilateral ureteral obstruction (UUO), a well-established model of renal fibrosis. We found that KLF11-deficiency exacerbates renal injury in the UUO model through activation of the TGF-β/SMAD signaling pathway and through activation of several pro-inflammatory chemokine signaling pathways. Based on these considerations, we conclude that agents increase KLF11 expression may provide novel therapeutic targets to slow the progression of CKD.

Real-time monitoring of liver fibrosis through embedded sensors in a microphysiological system

Hepatic fibrosis is a foreshadowing of future adverse events like liver cirrhosis, liver failure, and cancer. Hepatic stellate cell activation is the main event of liver fibrosis, which results in excessive extracellular matrix deposition and hepatic parenchyma's disintegration. Several biochemical and molecular assays have been introduced for in vitro study of the hepatic fibrosis progression. However, they do not forecast real-time events happening to the in vitro models. Trans-epithelial electrical resistance (TEER) is used in cell culture science to measure cell monolayer barrier integrity. Herein, we explored TEER measurement's utility for monitoring fibrosis development in a dynamic cell culture microphysiological system. Immortal HepG2 cells and fibroblasts were co-cultured, and transforming growth factor β1 (TGF-β1) was used as a fibrosis stimulus to create a liver fibrosis-on-chip model. A glass chip-based embedded TEER and reactive oxygen species (ROS) sensors were employed to gauge the effect of TGF-β1 within the microphysiological system, which promotes a positive feedback response in fibrosis development. Furthermore, albumin, Urea, CYP450 measurements, and immunofluorescent microscopy were performed to correlate the following data with embedded sensors responses. We found that chip embedded electrochemical sensors could be used as a potential substitute for conventional end-point assays for studying fibrosis in microphysiological systems.

BMP-6 and SMAD4 gene expression is altered in cumulus cells from women with endometriosis-associated infertility

INTRODUCTION

Oocyte competence and quality depend on communication between the oocyte and the cumulus and theca cells. In the preantral phase, the members of the transforming growth factor β (TGF-β) superfamily are responsible for this communication and play an important role in folliculogenesis. Members of the TGF-β superfamily are related to endometriosis (overexpression in the ectopic endometrium); however, few studies have explored these proteins as influencing fertility in endometriosis. Considering endometriosis-related infertility and to better understand the role of the TGF-β superfamily members in the antral phase in women with endometriosis, this research investigated the gene expression of the genes for ligands AMH, BMP-6, GDF-9, INHA, INHBB, and TGFβ3; receptors AMHR2, BMPR2, and TGFβR3; and intracellular signalling: SMAD3 and SMAD4.

MATERIAL AND METHODS

The gene expression of AMH, BMP-6, GDF-9, INHA, INHBB, TGFβ3, AMHR2, BMPR2, TGFβR3, SMAD3, and SMAD4 in cumulus cells was investigated through quantitative real-time PCR in a case-control study including infertile women with and without peritoneal endometriosis undergoing in vitro fertilization.

RESULTS

Age and outcomes of assisted reproduction were similar between the groups (P > .05). However, women with endometriosis showed reduced expression of BMP-6 and SMAD4 (P < .05) in cumulus cells compared with the control group, other genes did not present altered gene expression in women with endometriosis (P > .05).

CONCLUSIONS

The reduced expression of BMP-6 and SMAD4 in women with peritoneal endometriosis compared with the control group indicates that granulosa (cumulus) cell function could be altered in these women.

Dioxin and endometriosis: a new possible relation based on epigenetic theory

Endometriosis is a chronic disease characterized by the growth of endometrial-like glands and stroma outside the uterine cavity. Nowadays, the exact etiology of endometriosis is unclear and the interaction between a variety of environmental physical and chemical compounds may potentially promote the disease in women with an individual susceptibility. The first demonstration of a relation between an environmental factor and endometriosis was obtained with the chronic dietary exposure of a primate colony to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Besides the well-known dioxin's pathway of action, several papers are focusing on the role of epigenetic mechanisms, a way through which the genome responds to the environment and can lead to permanent changes in gene expression until affecting the phenotypes or cause disease. In this review, we focus on the possible role of dioxin epigenetics modification in endometriosis.

Anti-inflammatory cytokines in endometriosis

Although the pathogenesis of endometriosis is not fully understood, it is often considered to be an inflammatory disease. An increasing number of studies suggest that differential expression of anti-inflammatory cytokines (e.g., interleukin-4 and -10, and transforming growth factor-β1) occurs in women with endometriosis, including in serum, peritoneal fluid and ectopic lesions. These anti-inflammatory cytokines also have indispensable roles in the progression of endometriosis, including by promoting survival, growth, invasion, differentiation, angiogenesis, and immune escape of the endometriotic lesions. In this review, we provide an overview of the expression, origin, function and regulation of anti-inflammatory cytokines in endometriosis, with brief discussion and perspectives on their future clinical implications in the diagnosis and therapy of the disease.

Increased α2-6 sialylation of endometrial cells contributes to the development of endometriosis

Endometriosis is a disease characterized by implants of endometrial tissue outside the uterine cavity and is strongly associated with infertility. Focal adhesion of endometrial tissue to the peritoneum is an indication of incipient endometriosis. In this study, we examined the effect of various cytokines that are known to be involved in the pathology of endometriosis on endometrial cell adhesion. Among the investigated cytokines, transforming growth factor-β1 (TGF-β1) increased adhesion of endometrial cells to the mesothelium through induction of α2-6 sialylation. The expression levels of β-galactoside α2-6 sialyltransferase (ST6Gal) 1 and ST6Gal2 were increased through activation of TGF-βRI/SMAD2/3 signaling in endometrial cells. In addition, we discovered that terminal sialic acid glycan epitopes of endometrial cells engage with sialic acid-binding immunoglobulin-like lectin-9 expressed on mesothelial cell surfaces. Interestingly, in an in vivo mouse endometriosis model, inhibition of endogenous sialic acid binding by a NeuAcα2-6Galβ1-4GlcNAc injection diminished TGF-β1-induced formation of endometriosis lesions. Based on these results, we suggest that increased sialylation of endometrial cells by TGF-β1 promotes the attachment of endometrium to the peritoneum, encouraging endometriosis outbreaks.

A growth factor involved in cell differentiation and proliferation contributes to the development of endometriosis by stimulating a protein modification mechanism that increases the adhesiveness of cells lining the uterus. Endometriosis results when these cells, known as endometrial cells, start growing outside the uterus causing pelvic pain, heavy periods and, in some cases, infertility. Ki-Tae Ha at Pusan National University, Yangsan, South Korea, and colleagues found that transforming growth factor-β1 signaling promoted the addition of sialic acid sugar units onto endometrial cell surface proteins. This modification enhanced the adhesion of endometrial cells to mesothelial cells, which line other internal organs, and the formation of endometriosis lesions in mice. Preventing sialic acid binding to its mesothelial cell receptor reduced lesion formation. The findings reveal a new molecular mechanism underlying endometriosis and a potential treatment strategy.

Impaired Localization of Claudin-11 in Endometriotic Epithelial Cells Compared to Endometrial Cells

Claudins are the major components of tight junctions and are often deregulated in human cancer, permitting escape of cancer cells along with the acquisition of invasive properties. Similarly, endometrial cells also show invasive capabilities; however, the role of tight junctions in endometriosis has only rarely been examined. In this study, we analyzed the protein expression and localization of claudin-7 and claudin-11 in human eutopic and ectopic endometrium and endometrial cell lines. We identified claudin-7 primarily at the basolateral junctions of the glandular epithelial cells in eutopic endometrium as well as in the ectopic lesions in nearly all glands and cysts. Quantification of claudin-7 localization by HSCORE showed a slight increase in peritoneal and deep infiltrating endometriosis (DIE) compared to eutopic endometrium. In contrast, claudin-11 was localized mainly in the apicolateral junctions in nearly all glandular epithelial cells of the eutopic endometrium. Interestingly, we observed a deregulation of claudin-11 localization to a basal or basolateral localization in ovarian (P < .001), peritoneal (P < .01), and DIE (P < .05) and a moderately decreased abundance in ovarian endometriosis. In endometrial cell lines, claudin-7 was only present in epithelial Ishikawa cells, and silencing by small-interfering RNA increased cell invasiveness. In contrast, claudin-11 could be demonstrated in Ishikawa and endometriotic 12Z and 49Z cells. Silencing of claudin-11 decreased invasiveness of 12Z slightly but significantly in 49Z. We suggest that although claudin-7 and claudin-11 can be found in nearly all eutopic and ectopic epithelial cells, the impaired localization of claudin-11 in ectopic endometrium might contribute to the pathogenesis of endometriosis.

Lysophosphatidic acid triggers cathepsin B-mediated invasiveness of human endometriotic cells

Extracellular lysophosphatidic acid (LPA) and the G-protein-coupled LPA receptors (LPAR) are involved in cell migration and invasion and found in the human endometrium. However, underlying mechanisms resulting in cellular invasion have been rarely investigated. We used stromal endometrial T-HESC, epithelial endometriotic 12Z, 49Z and Ishikawa cells. Interestingly, proliferation of T-HESC cells was strongly increased after LPA treatment, whereas the epithelial cell lines only showed a moderate increase. LPA increased invasion of 12Z and 49Z strongly and significantly. The LPAR inhibitor Ki16425 (LPAR1/3) attenuated significantly LPA-induced invasiveness of 12Z, which was confirmed by LPAR1 and LPAR3 siRNAs, showing that both LPA receptors contribute to invasiveness of 12Z cells. Investigation of cell invasion with an antibody-based protease array revealed mainly differences in cathepsins and especially cathepsin B between 12Z compared to the less invasive Ishikawa. Stimulation with LPA showed a time- and dose-dependent increased secretion of cathepsin B which was inhibited by the Gq inhibitor YM-254890 and Gi/o inhibitor pertussis toxin in the 12Z cells, again highlighting the importance of LPAR1/3. The activity of intracellular and secreted cathepsin B was significantly upregulated in LPA-treated samples. Inhibition of cathepsin B with the specific inhibitor CA074 significantly reduced LPA-increased invasion of 12Z. Our results reveal a novel role of LPA-mediated secretion of cathepsin B which stimulated invasion of endometriotic epithelial cells mainly via LPAR1 and LPAR3. These findings may deepen our understanding how endometriotic cells invade into ectopic sites, and provide new insights into the role of LPA and cathepsin B in cellular invasion.

Epigenetic Therapy: Novel Translational Implications for Arrest of Environmental Dioxin-Induced Disease in Females

Increased toxicant exposure and resultant environmentally induced diseases are a tradeoff of industrial productivity. Dioxin [2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD)], a ubiquitous byproduct, is associated with a spectrum of diseases including endometriosis, a common, chronic disease in women. TCDD activates cytochrome (CYP) p450 metabolic enzymes that alter organ function to cause disease. In contrast, the transcription factor, Krüppel-like factor (KLF) 11, represses these enzymes via epigenetic mechanisms. In this study, we characterized these opposing mechanisms in vitro and in vivo as well as determining potential translational implications of epigenetic inhibitor therapy. KLF11 antagonized TCDD-mediated activation of CYP3A4 gene expression and function in endometrial cells. The repression was pharmacologically replicated by selective use of an epigenetic histone acetyltransferase inhibitor (HATI). We further showed phenotypic relevance of this mechanism using an animal model for endometriosis. Fibrotic extent in TCDD-exposed wild-type animals was similar to that previously observed in Klf11-/- animals. When TCDD-exposed animals were treated with a HATI, Cyp3 messenger RNA levels and protein expression decreased along with disease progression. Fibrotic progression is ubiquitous in environmentally induced chronic, untreatable diseases; this report shows that relentless disease progression can be arrested through targeted epigenetic modulation of protective mechanisms.

The TGF-β Family in the Reproductive Tract

The transforming growth factor β (TGF-β) family has a profound impact on the reproductive function of various organisms. In this review, we discuss how highly conserved members of the TGF-β family influence the reproductive function across several species. We briefly discuss how TGF-β-related proteins balance germ-cell proliferation and differentiation as well as dauer entry and exit in Caenorhabditis elegans. In Drosophila melanogaster, TGF-β-related proteins maintain germ stem-cell identity and eggshell patterning. We then provide an in-depth analysis of landmark studies performed using transgenic mouse models and discuss how these data have uncovered basic developmental aspects of male and female reproductive development. In particular, we discuss the roles of the various TGF-β family ligands and receptors in primordial germ-cell development, sexual differentiation, and gonadal cell development. We also discuss how mutant mouse studies showed the contribution of TGF-β family signaling to embryonic and postnatal testis and ovarian development. We conclude the review by describing data obtained from human studies, which highlight the importance of the TGF-β family in normal female reproductive function during pregnancy and in various gynecologic pathologies.

Progressive Fibrosis: A Progesterone- and KLF11-Mediated Sexually Dimorphic Female Response

Progressive scarring is ubiquitous postoperatively and in an array of chronic systemic diseases. Recent studies indicate that such scarring has a high female propensity; females are also almost exclusively affected by endometriosis, a common sex steroid-dependent fibrotic disease. Endometriosis-related fibrosis is regulated epigenetically through transcription factor Krüppel-like factor 11 (KLF11). In response to surgical induction of endometriosis, Klf11-/- female mice develop significant fibrosis in contrast to wild-type mice. We therefore hypothesized that female fibrotic predilection was mediated by differential sex steroid regulation of KLF11/collagen 1a1 signaling and investigated the fibrotic response in wild-type and Klf11-/- male and female animals using a sterile peritonitis model. Fibrosis selectively developed in Klf11-/- females. Fibrosis in these animals was almost completely abrogated by ovariectomy. Ovariectomized animals were selectively supplemented with estradiol, medroxyprogesterone acetate (MPA), or dihydrotestosterone; fibrosis was only observed in mice exposed to MPA. Fibrosis therefore selectively developed in Klf11-/- female mice in response to physiological or pharmacological progesterone. The fibrotic response in these animals was also mitigated in response to antiprogestin therapy. Profibrotic gene expression was activated in a primary human peritoneal cell line in response to KLF11 short hairpin RNA and MPA but not estradiol. KLF11/collagen 1a1 signaling previously shown to be linked to fibrosis was thus selectively dysregulated in MPA-treated cells. Our in vivo and in vitro findings in an animal model and human cells, respectively, suggest that progressive fibrotic scarring is a sexually dimorphic response irrespective of etiology; moreover, it is responsive to novel, individualized therapeutic intervention.

Is cytochrome P450 3A4 regulated by menstrual cycle hormones in control endometrium and endometriosis?

The estrogen-metabolizing activities of cytochrome P450 (CYP) enzymes have been implicated in endometriosis. However, their regulation in various sources of endometrial tissue under different hormonal conditions has not been clarified. Our objective was to study the hormone regulation of a specific CYP enzyme, namely CYP3A4, in control (n = 15) and endometriosis patients (n = 42). To this end, we evaluated mRNA expression (using real-time PCR) of CYP3A4 in tissue samples classified according to the phase of menstrual cycle at which they were obtained as confirmed by the related circulating hormone levels. Protein expression was also evaluated by Western Blot. In order to further investigate the hormonal regulation of CYP3A4, stromal cells from ovarian endometriotic lesions were cultured with the prevailing hormones of the distinct phases of the menstrual cycle. We observed that all control and endometriosis tissues express CYP3A4. Nevertheless, changes in CYP3A4 gene expression related to cycle phase were only seen in the control eutopic endometrium and not in samples from endometriosis patients, with an increase in the luteal phase. Stromal cells isolated from ovarian endometriotic lesions expressed CYP3A4 and their exposure to luteal phase-mimicking hormones (estradiol + progesterone) reduced CYP3A4 mRNA in parallel with a diminished expression of the corresponding receptors, estrogen receptor alpha and progesterone receptor. Our findings suggest that steroid hormones are able to regulate CYP3A4 mRNA expression, although the circulating levels of these hormones can only regulate control endometrium and not endometriosis tissues, probably because of dysregulated local steroid concentration in these latter samples.

Abnormal Uterine Bleeding Is Associated With Increased BMP7 Expression in Human Endometrium

Abnormal uterine bleeding (AUB), a common health concern of women, is a heterogeneous clinical entity that is traditionally categorized into organic and nonorganic causes. Despite varied pharmacologic treatments, few offer sustained efficacy, as most are empiric, unfocused, and do not directly address underlying dysregulated molecular mechanisms. Characterization of such molecular derangements affords the opportunity to develop and use novel, more successful treatments for AUB. Given its implication in other organ systems, we hypothesized that bone morphogenetic protein (BMP) expression is altered in patients with AUB and hence comprehensively investigated dysregulation of BMP signaling pathways by systematically screening 489 samples from 365 patients for differences in the expression of BMP2, 4, 6, and 7 ligands, BMPR1A and B receptors, and downstream SMAD4, 6, and 7 proteins. Expression analysis was correlated clinically with data abstracted from medical records, including bleeding history, age at procedure, ethnicity, body mass index, hormone treatment, and histological diagnosis of fibroids, polyps, adenomyosis, hyperplasia, and cancer. Expression of BMP7 ligand was significantly increased in patients with AUB (H-score: 18.0 vs 26.7; P < .0001). Patients reporting heavy menstrual bleeding (menorrhagia) as their specific AUB pattern demonstrated significantly higher BMP7 expression. Significantly, no differences in the expression of any other BMP ligands, receptors, or SMAD proteins were observed in this large patient cohort. However, expression of BMPR1A, BMPR1B, and SMAD4 was significantly decreased in cancer compared to benign samples. Our study demonstrates that BMP7 is a promising target for future investigation and pharmacologic treatment of AUB.