Prognosis of ischemic stroke patients with both aortic atheroma and cardioembolic sources

This study aimed to investigate the relationship between complex aortic plaque (CAP) and short-term as well as long-term outcomes following cardioembolic stroke. CAP is a known risk factor for occurrence and recurrence of ischemic stroke. However, the association of CAP on cardioembolic stroke remains unclear. This was retrospective study using prospective cohort of consecutive patients with cardioembolic stroke who underwent transesophageal echocardiography. The functional outcome was evaluated using the modified Rankin Scale score at 3 months, and long-term outcomes were assessed by recurrence of ischemic stroke and occurrence of major adverse cardiovascular events (MACE). Among 759 patients with cardioembolic stroke, 91 (12.0%) had CAP. Early ischemic stroke recurrence within 3 months was associated with CAP (p = 0.025), whereas CAP was not associated with functional outcome at 3 months (odd ratio  1.01, 95% confidence interval [CI]  0.57-1.84, p = 0.973). During a median follow-up of 3.02 years, CAP was significantly associated with ischemic stroke recurrence (hazard ratio = 2.68, 95% CI 1.48-4.88, p = 0.001) and MACE occurrence (hazard ratio = 1.61, 95% CI 1.03-2.51, p = 0.039). In conclusion, CAP was associated with early ischemic stroke recurrence and poor long-term outcomes in patients with cardioembolic stroke. It might be helpful to consider transesophageal echocardiography for patients with cardioembolic stroke to identify CAP.

ARG1 Is a Potential Prognostic Marker in Metastatic Endometrial Cancer

Endometrial cancer (EC) is the most common gynecologic malignancy. While the majority of patients present with early-stage and low-grade EC and have an excellent prognosis, a subset has metastatic disease at presentation or develops distant recurrence after initial treatment of the primary. However, the lack of prognostic biomarkers for metastatic EC is a critical barrier. Arginase 1 (ARG1) regulates the last step of the urea cycle, and an increase in ARG1 has been correlated as a poor prognostic factor in a variety of cancers. In the present study, ARG1 expression was evaluated as a potential prognostic marker for metastatic EC in endometrial hyperplasia and cancer of mice with Pten mutation as well as Pten and Mig-6 double mutations. While Pten mutation in the uterus is not sufficient for distant metastasis, mice with concurrent ablation of Mig-6 and Pten develop distant metastasis. Our immunostaining and RT-qPCR analysis revealed that the expression of ARG1 in early stage of EC as well as endometrial hyperplasia from mice deficient in Mig-6 and Pten mutations significantly increased compared to Pten mutation in the uterus. The results suggest that a high level of ARG1 is associated with poor prognosis in association with EC of mouse.

Transcriptomic changes in eutopic endometrium and ectopic lesions during endometriosis progression in a mouse model

OBJECTIVE

To identify the transcriptomic changes of ectopic lesions and eutopic endometrial tissues during the progression of endometriosis, we performed transcriptomic analysis in the eutopic endometrium and ectopic lesions.

DESIGN

Laboratory study.

SETTING

Academic medical center.

ANIMALS

Four fertile and 4 subfertile Pgrcre/+Rosa26mTmG/+ mice with endometriosis, and 4 sham mice for each group of endometriosis mice as control. These mice underwent either surgery to induce endometriosis or sham surgery. Fertile sham and mice with endometriosis were used 1 month after surgery, whereas subfertile ones were used 3 months after surgery.

INTERVENTIONS

Early and chronic effects of endometriosis on transcriptomics of ectopic lesions and eutopic endometrium.

MAIN OUTCOME MEASURES

RNA-sequencing analysis and identification of differentially expressed genes and pathways in the ectopic lesions and eutopic uteri from mice with endometriosis and sham mice at day 3.5 of pregnancy.

RESULTS

Our mouse model recapitulates the transcriptomic changes of ectopic lesions in humans. RNA-sequencing analysis was performed in ectopic lesions and eutopic uteri from mice with or without endometriosis during the progression of the disease. Estrogen activity, inflammation, angiogenesis, and fibrosis pathways were consistently elevated in all the ectopic lesions compared with eutopic endometrium. Cholesterol/glucose synthesis and stem cell pluripotency pathways were more enhanced in ectopic lesions from subfertile mice compared with their eutopic endometrium. Dysregulation of infiltration of macrophage, dendritic, T and B cells was validated with the use of immunohistochemistry in ectopic lesions. Multiple ligand-receptor pairs between the ectopic and eutopic endometrium were altered compared with the sham endometrium. Suppressed WNT and EGF pathways were only found in the eutopic endometrium from subfertile not fertile mice compared with sham.

CONCLUSIONS

Our mouse endometriosis model recapitulates the transcriptomics of ectopic lesions in humans. Our transcriptomic analysis during endometriosis progression in our mouse model will help us understand the pathophysiology of endometriosis.

Long-term outcomes of patients with embolic stroke of undetermined source according to subtype

The prognosis of patients with embolic stroke of undetermined source (ESUS) may vary according to the underlying cause. Therefore, we aimed to divide ESUS into subtypes and assess the long-term outcomes. Consecutive patients with acute ischemic stroke who underwent a comprehensive workup, including transesophageal echocardiography and prolonged electrocardiography monitoring, were enrolled. We classified ESUS into minor cardioembolic (CE) ESUS, arteriogenic ESUS, two or more causes ESUS, and no cause ESUS. Arteriogenic ESUS was sub-classified into complex aortic plaque (CAP) ESUS and non-stenotic (< 50%) relevant artery plaque (NAP) ESUS. A total of 775 patients were enrolled. During 1286 ± 748 days follow-up, 116 major adverse cardiovascular events (MACE) occurred (4.2 events/100 patient-years). Among the ESUS subtypes, CAP ESUS was associated with the highest MACE frequency (9.7/100 patient-years, p = 0.021). Cox regression analyses showed that CAP ESUS was associated with MACE (hazard ratio 2.466, 95% confidence interval 1.305-4.660) and any stroke recurrence (hazard ratio 2.470, 95% confidence interval, 1.108-5.508). The prognosis of ESUS varies according to the subtype, with CAP ESUS having the worst prognosis. Categorizing ESUS into subtypes could improve patient care and refine clinical trials.

ERBB2 Targeting Reveals a Significant Suppression of Tumorigenesis in Murine Endometrial Cancer with Pten Mutation

Endometrial cancer is the most common gynecologic malignancy. PTEN is a negative regulator of PI3K signaling and is deficient in > 50% of primary human endometrial cancer. Amplification of ERBB2 promotes tumorigenesis and pathogenesis of several human cancers. However, the effect of ERBB2 targeting has not been studied in endometrial cancer with PTEN mutations. The murine model Pgrcre/+Erbb2f/fPtenf/f (Erbb2d/d Ptend/d) was developed to evaluate the effect of ERBB2 targeted therapy in endometrial cancer with PTEN deficiency. Histopathological and molecular analysis was performed for Ptend/d and Erbb2d/dPtend/d mice. Histopathological analysis revealed that Erbb2d/dPtend/d mice significantly reduced development and progression of endometrial cancer compared to Ptend/d mice. Furthermore, percentage of proliferative cells in Erbb2d/dPtend/d mice revealed anti-tumorigenic effect of Erbb2 ablation compared to Ptend/d mice. Our results demonstrate that Erbb2 ablation reveals a significant suppression of tumorigenesis on endometrial cancer of Ptend/d mice. Our results suggest that Erbb2 functions as an oncogene in endometrial cancer of Ptend/d mice implying that Erbb2 targeting can be used as an effective therapeutic approach for treatment of endometrial cancer with PTEN deficiency to hinder cancer development.

Epigenetic Dysregulation in Endometriosis: Implications for Pathophysiology and Therapeutics

Endometriosis is a prevalent gynecological condition associated with pelvic pain and infertility. Despite more than a century of research, the etiology of endometriosis still eludes scientific consensus. This lack of clarity has resulted in suboptimal prevention, diagnosis, and treatment options. Evidence of genetic contributors to endometriosis is interesting but limited; however, significant progress has been made in recent years in identifying an epigenetic role in the pathogenesis of endometriosis through clinical studies, in vitro cell culture experiments, and in vivo animal models. The predominant findings include endometriosis-related differential expression of DNA methyltransferases and demethylases, histone deacetylases, methyltransferases, and demethylases, and regulators of chromatin architecture. There is also an emerging role for miRNAs in controlling epigenetic regulators in the endometrium and endometriosis. Changes in these epigenetic regulators result in differential chromatin organization and DNA methylation, with consequences for gene expression independent of a genetic sequence. Epigenetically altered expression of genes related to steroid hormone production and signaling, immune regulation, and endometrial cell identity and function have all been identified and appear to play into the pathophysiological mechanisms of endometriosis and resulting infertility. This review summarizes and critically discusses early seminal findings, the ever-growing recent evidence of epigenetic contributions to the pathophysiology of endometriosis, and implications for proposed epigenetically targeted therapeutics.

ARG1 is a potential prognostic marker in metastatic and recurrent endometrial cancer

Endometrial cancer (EC) is the most common gynecologic malignancy. While the majority of patients present with early-stage and low-grade EC and have an excellent prognosis, a subset has metastatic disease at presentation, or develops distant recurrence after initial treatment of the primary. However, the lack of prognostic biomarkers for metastatic EC is a critical barrier. Arginase 1 (ARG1) regulates the last step of the urea cycle, and an increase in ARG1 has been correlated as a poor prognostic factor in a variety of cancers. In the present study, ARG1 expression was evaluated as a potential prognostic marker for metastatic EC in endometrial hyperplasia and cancer of mice with Pten mutation as well as Pten and Mig-6 double mutations. While Pten mutation in the uterus is not sufficient for distant metastasis, mice with concurrent ablation of Mig-6 and Pten develop distant metastasis. Our immunostaining and RT-qPCR analysis revealed that the expression of ARG1 in early stage of EC as well as endometrial hyperplasia from mice deficient in Mig-6 and Pten mutations significantly increased compared to Pten mutation in the uterus. The results suggest that a high level of ARG1 is associated with poor prognosis in association with EC of mouse.

Pancreatic loss of Mig6 alters murine endocrine cell fate and protects functional beta cell mass in an STZ-induced model of diabetes

Background

Maintaining functional beta cell mass (BCM) to meet glycemic demands is essential to preventing or reversing the progression of diabetes. Yet the mechanisms that establish and regulate endocrine cell fate are incompletely understood. We sought to determine the impact of deletion of mitogen-inducible gene 6 (Mig6), a negative feedback inhibitor of epidermal growth factor receptor (EGFR) signaling, on mouse endocrine cell fate. The extent to which loss of Mig6 might protect against loss of functional BCM in a multiple very low dose (MVLD) STZ-induced model of diabetes was also determined.

Methods

Ten-week-old male mice with whole pancreas (Pdx1:Cre, PKO) and beta cell-specific (Ins1:Cre, BKO) knockout of Mig6 were used alongside control (CON) littermates. Mice were given MVLD STZ (35 mg/kg for five days) to damage beta cells and induce hyperglycemia. In vivo fasting blood glucose and glucose tolerance were used to assess beta cell function. Histological analyses of isolated pancreata were utilized to assess islet morphology and beta cell mass. We also identified histological markers of beta cell replication, dedifferentiation, and death. Isolated islets were used to reveal mRNA and protein markers of beta cell fate and function.

Results

PKO mice had significantly increased alpha cell mass with no detectable changes to beta or delta cells. The increase in alpha cells alone did not impact glucose tolerance, BCM, or beta cell function. Following STZ treatment, PKO mice had 18±8% higher BCM than CON littermates and improved glucose tolerance. Interestingly, beta cell-specific loss of Mig6 was insufficient for protection, and BKO mice had no discernable differences compared to CON mice. The increase in BCM in PKO mice was the result of decreased beta cell loss and increased beta cell replication. Finally, STZ-treated PKO mice had more Ins+/Gcg+ bi-hormonal cells compared to controls suggesting alpha to beta cell transdifferentiation.

Conclusions

Mig6 exerted differential effects on alpha and beta cell fate. Pancreatic loss of Mig6 reduced beta cell loss and promoted beta cell growth following STZ. Thus, suppression of Mig6 may provide relief of diabetes.

Notch effector recombination signal binding protein for immunoglobulin kappa J signaling is required for the initiation of endometrial stromal cell decidualization†

The Notch signaling pathway is required for reproductive success. This pathway activates its transcriptional effector, recombination signal binding protein for immunoglobulin kappa J (Rbpj), to induce transcription of its target genes. This signaling pathway is required for successful decidualization, implantation, and uterine repair following parturition. To identify the compartmental specific roles of the Notch signaling pathway in the establishment of pregnancy, we generated epithelial and decidual stromal cell specific knockouts of Rbpj utilizing lactoferrin iCre and Prl8A2 iCre, respectively. Both conditional knockout mouse models were fertile. The Rbpj epithelial knockout mice displayed 27% resorption sites at E15.5, but this did not significantly impact the number of live born pups compared with controls. In addition, the Rbpj epithelial knockout mice displayed increased estrogen signaling in their stromal compartment. Given that both mouse models exhibited fertility comparable to control animals, the epithelial and stromal specific nature of the iCre recombinases utilized, and previously published Rbpj total uterine knockout mouse models, we conclude that Notch effector Rbpj signaling is required at the initiation of pregnancy to support decidualization in stromal cells, but that Rbpj is not required in the epithelial compartment nor is it required for post-implantation pregnancy success.

Leptin Stimulates Endometriosis Development in Mouse Models

Endometriosis is a chronic inflammatory condition in women, and obesity leads to an inflammatory condition that is directly involved in the etiology of endometriosis. However, observational studies have shown an inverse correlation between endometriosis and a low body mass index (BMI). Obesity does not protect against endometriosis, and on the contrary, an increased BMI may lead to more severe forms of the disease. To determine the effect of obesity on endometriosis, diet-induced and genetically engineered obese mouse models were integrated with endometriosis mouse models with fluorescence-tagged ectopic lesions. High-fat diet-induced obese mice revealed a significant increase in endometriosis development compared with regular-diet control mice. However, obese recipient mice with leptin deficiency and leptin receptor deficiency showed suppressed endometriosis development compared with control mice. Furthermore, donor uterine tissues with leptin deficiency and leptin receptor deficiency suppressed endometriosis development compared with control donor in control recipient mice. Importantly, we revealed that aberrant high levels of leptin concentration significantly increased endometriosis development compared with vehicle treatment group in control mice with normal body weight. Our results suggest that leptin and its receptor are critical for endometriosis development.

SIRT1 plays an important role in implantation and decidualization during mouse early pregnancy

Sirtuin 1 (SIRT1) is a member of the sirtuin family that functions to deacetylate both histones and non-histone proteins. Previous studies have identified significant SIRT1 upregulation in eutopic endometrium from infertile women with endometriosis. However, SIRT1 function in the uterus has not been directly studied. Using immunochemistry analysis, we found SIRT1 to be most strongly expressed at GD4.5 and GD5.5 in decidualized cells and at GD7.5 in secondary decidual cells in mouse. To assess the role of SIRT1 in uterine function, we generated uterine Sirt1 conditional knockout mice (Pgrcre/+Sirt1f/f; Sirt1d/d). A 6-month fertility trial revealed that Sirt1d/d females were subfertile. Implantation site numbers were significantly decreased in Sirt1d/d mice compared with controls at GD5.5. Sirt1d/d implantation sites at GD4.5 could be divided into two groups, Group #1 with luminal closure and nonspecific COX2 expression compared with controls (14/20) and Group #2 with an open lumen and no COX2 (6/20). In Sirt1d/d Group #1, nuclear FOXO1 expression in luminal epithelial cells was significantly decreased. In Sirt1d/d Group #2, nuclear FOXO1 expression was almost completely absent, and there was strong PGR expression in epithelial cells. At GD5.5, stromal PGR and COX2 were significantly decreased in Sirt1d/d uterine in the areas surrounding the embryo compared with controls, indicating defective decidualization. An artificially induced decidualization test revealed that Sirt1d/d females showed defects in decidualization response. All together, these data suggest that SIRT1 is important for decidualization and contributes to preparing a receptive endometrium for successful implantation.

A Mouse Model of Endometriosis with Nanoparticle Labeling for In Vivo Photoacoustic Imaging

Endometriosis is a condition of the female reproductive tract characterized by endometrium-like tissue growing outside the uterus. Though it is a common cause of pelvic pain and infertility, there is currently no reliable noninvasive method to diagnose the presence of endometriosis without surgery, and the pathophysiological mechanisms that lead to the occurrence of symptoms require further inquiry. Due to patient heterogeneity and delayed diagnosis, animal models are commonly used to study the development of endometriosis, but these are costly due to the large number of animals needed to test various treatments and experimental conditions at multiple endpoints. Here, we describe a method for synthesis of multimodal imaging gold-fluorescein isothiocyanate (FITC) nanoparticles with preclinical application via induction of nanoparticle-labeled endometriosis-like lesions in mice. Labeling donor endometrial tissue fragments with gold-FITC nanoparticles prior to induction of endometriosis in recipients enables in vivo detection of the gold-labeled lesions with photoacoustic imaging. The same imaging method can be used to visualize embryos noninvasively in pregnant mice. Furthermore, the conjugated FITC dye on the gold nanoparticles allows easy isolation of labeled lesion tissue under a fluorescence dissection microscope. After dissection, the presence of gold-FITC nanoparticles and endometrium-like histology of lesions can be verified through fluorescence imaging, gold enhancement, and immunostaining. This method for in vivo imaging of endometriosis-like lesions and fluorescence-guided dissection will permit new experimental possibilities for the longitudinal study of endometriosis development and progression as well as endometriosis-related infertility.

Endometrial Epithelial ARID1A Is Required for Uterine Immune Homeostasis during Early Pregnancy

A growing body of work suggests epigenetic dysregulation contributes to endometriosis pathophysiology and female infertility. The chromatin remodeling complex subunit AT-rich interaction domain 1A (ARID1A) must be properly expressed to maintain normal uterine function. Endometrial epithelial ARID1A is indispensable for pregnancy establishment in mice through regulation of endometrial gland function; however, ARID1A expression is decreased in infertile women with endometriosis. We hypothesized that ARID1A performs critical operations in the endometrial epithelium necessary for fertility besides maintaining gland function. To identify alterations in uterine gene expression resulting from loss of epithelial ARID1A, we performed RNA-sequencing analysis on pre-implantation uteri from Ltf^iCre/+Arid1a^f/f and control mice. Differential expression analysis identified 4181 differentially expressed genes enriched for immune-related ingenuity canonical pathways including agranulocyte adhesion and diapedesis and natural killer cell signaling. RT-qPCR confirmed an increase in pro-inflammatory cytokine and macrophage-related gene expression but a decrease in natural killer cell signaling. Immunostaining confirmed a uterus-specific increase in macrophage infiltration. Flow cytometry delineated an increase in inflammatory macrophages and a decrease in uterine dendritic cells in Ltf^iCre/+Arid1a^f/f uteri. These findings demonstrate a role for endometrial epithelial ARID1A in suppressing inflammation and maintaining uterine immune homeostasis, which are required for successful pregnancy and gynecological health.

Nuclear Progesterone Receptor Expressed by the Cortical Thymic Epithelial Cells Dictates Thymus Involution in Murine Pregnancy

Progesterone is a gonadal pro-gestational hormone that is absolutely necessary for the success of pregnancy. Most notable actions of progesterone are observed in the female reproductive organs, the uterus and the ovary. Acting through the nuclear progesterone receptor (PGR), progesterone prepares the endometrium for implantation of the embryo. Interestingly, the maternal thymus also is a known expressor of Pgr; its absence is associated with murine pregnancy complications. However, the localization of its expression and its functional importance were not known. Here, we used a transgenic dual fluorescent reporter mouse model and genetic deletion of Pgr in Foxn1+ thymic epithelial cells (TEC) to demonstrate TEC-specific Pgr expression in pregnancy, especially in the cortex where thymocyte maturation occurs. Using our TEC-specific Pgr deletion mouse model, we demonstrate that TEC-specific Pgr is necessary for pregnancy-induced thymic involution in pregnancy. Our investigation reveals that PGR expression is upregulated in the cortical thymic epithelial cells during pregnancy, and that PGR expression is important for thymic involution during murine pregnancy.

Loss of MIG-6 results in endometrial progesterone resistance via ERBB2

Female subfertility is highly associated with endometriosis. Endometrial progesterone resistance is suggested as a crucial element in the development of endometrial diseases. We report that MIG-6 is downregulated in the endometrium of infertile women with endometriosis and in a non-human primate model of endometriosis. We find ERBB2 overexpression in the endometrium of uterine-specific Mig-6 knockout mice (Pgr^cre/+Mig-6^f/f; Mig-6^d/d). To investigate the effect of ERBB2 targeting on endometrial progesterone resistance, fertility, and endometriosis, we introduce Erbb2 ablation in Mig-6^d/d mice (Mig-6^d/dErbb2^d/d mice). The additional knockout of Erbb2 rescues all phenotypes seen in Mig-6^d/d mice. Transcriptomic analysis shows that genes differentially expressed in Mig-6^d/d mice revert to their normal expression in Mig-6^d/dErbb2^d/d mice. Together, our results demonstrate that ERBB2 overexpression in endometrium with MIG-6 deficiency causes endometrial progesterone resistance and a nonreceptive endometrium in endometriosis-related infertility, and ERBB2 targeting reverses these effects.

Female subfertility is highly associated with endometriosis. Here the authors show that progesterone-induced MIG-6 is reduced in endometrium of infertile women and non-human primates with endometriosis, and in a mouse model find that Erbb2 is the key mediator of Mig-6 loss induced endometriosis-related infertility.

Role of SIRT1 and Progesterone Resistance in Normal and Abnormal Endometrium

CONTEXT

Progesterone resistance, a known pathologic condition associated with a reduced cellular response to progesterone and heightened estrogen responses, appears to have a normal physiologic role in mammalian reproduction. The molecular mechanism responsible for progesterone resistance in normal and abnormal endometrium remains unclear.

OBJECTIVE

To examine the roles of sirtuin-1 (SIRT1) in normal endometrium as well as endometrium associated with infertility and endometriosis, as an epigenetic modulator associated with progesterone resistance.

METHODS

SIRT1 expression was examined by Western blot, quantitative real-time polymerase chain reaction, and immunohistochemistry in mouse uterus and human endometrium. Mice with uterine specific Sirt1 overexpression were developed to examine SIRT1's role in endometrial function and endometriosis development. EX-527, a SIRT1 inhibitor, and SRT1720, a SIRT1 agonist, were also used to evaluate SIRT1 effect on endometriosis.

RESULTS

In normal healthy women, endometrial SIRT1 is expressed only during menses. SIRT1 was dramatically overexpressed in the endometrium from women with endometriosis in both the epithelium and stroma. In mice, SIRT1 is expressed at the time of implantation between day 4.5 and 5.5 of pregnancy. Overexpression of SIRT1 in the mouse uterus leads to subfertility due to implantation failure, decidualization defects and progesterone resistance. SIRT1 overexpression in endometriotic lesions promotes worsening endometriosis development. EX-527 significantly reduced the number of endometriotic lesions in the mouse endometriosis model.

CONCLUSIONS

SIRT1 expression and progesterone resistance appears to play roles in normal endometrial functions. Aberrant SIRT1 expression contributes to progesterone resistance and may participate in the pathophysiology of endometriosis. SIRT1 is a novel and targetable protein for the diagnosis as well as treatment of endometriosis and the associated infertility seen in this disease.

Corrigendum: Nuclear Progesterone Receptor Expressed by the Cortical Thymic Epithelial Cells Dictates Thymus Involution in Murine Pregnancy

[This corrects the article DOI: 10.3389/fendo.2022.846226.].

ARID1A and PGR proteins interact in the endometrium and reveal a positive correlation in endometriosis

Endometriosis is a disorder in which endometrial cells normally limited to the lining of the uterus proliferate outside the uterine cavity and can cause pelvic pain and infertility. ARID1A levels are significantly reduced in the eutopic endometrium from women with endometriosis. Uterine specific Arid1a knock-out mice were infertile due to loss of epithelial progesterone receptor (PGR) signaling. However, the functional association of ARID1A and PGR in endometriosis has not been studied. We examined the expression patterns and co-localization of ARID1A and PGR in eutopic endometrium from women with and without endometriosis using immunostaining and Western blot analysis. ARID1A and PGR proteins co-localized in the epithelium during the proliferative and the early secretory phases. Our immunoprecipitation analysis and proximity ligation assay (PLA) revealed physical interaction between ARID1A and PGR-A but not PGR-B in the mouse and human endometrium. ARID1A levels positively correlated with PGR levels in the eutopic endometrium of women with endometriosis. Our results bring new perspectives on the molecular mechanisms involved in endometrial receptivity and progesterone resistance in endometriosis. The interrelationship between ARID1A and PGR may contribute to explaining the non-receptive endometrium in endometriosis-related infertility.

Genetic and epigenetic changes in the eutopic endometrium of women with endometriosis: association with decreased endometrial αvβ3 integrin expression

About 40% of women with infertility and 70% of women with pelvic pain suffer from endometriosis. The pregnancy rate in women undergoing IVF with low endometrial integrin αvβ3 (LEI) expression is significantly lower compared to the women with high endometrial integrin αvβ3 (HEI). Mid-secretory eutopic endometrial biopsies were obtained from healthy controls (C; n=3), and women with HEI (n=4) and LEI (n=4) and endometriosis. Changes in gene expression were assessed using human gene arrays and DNA methylation data were derived using 385 K Two-Array Promoter Arrays. Transcriptional analysis revealed that LEI and C groups clustered separately with 396 differentially expressed genes (DEGs) (P<0.01: 275 up and 121 down) demonstrating that transcriptional and epigenetic changes are distinct in the LEI eutopic endometrium compared to the C and HEI group. In contrast, HEI vs C and HEI vs LEI comparisons only identified 83 and 45 DEGs, respectively. The methylation promoter array identified 1304 differentially methylated regions in the LEI vs C comparison. The overlap of gene and methylation array data identified 14 epigenetically dysregulated genes and quantitative RT-PCR analysis validated the transcriptomic findings. The analysis also revealed that aryl hydrocarbon receptor (AHR) was hypomethylated and significantly overexpressed in LEI samples compared to C. Further analysis validated that AHR transcript and protein expression are significantly (P<0.05) increased in LEI women compared to C. The increase in AHR, together with the altered methylation status of the 14 additional genes, may provide a diagnostic tool to identify the subset of women who have endometriosis-associated infertility.

Abstract PO041: Everolimus and MK-2206 reverse P4-resistant endometrial hyperplasia in Mig-6 mutant mice

Endometrial cancer is the most frequent type of gynecological tumor in the United States. Hysterectomy, the surgical removal of the uterus, is the main therapy for endometrial cancer, but this is not an option for women seeking to preserve their fertility. In cases of early-stage endometrial cancer and endometrial hyperplasia, hormonal therapy is a vital nonsurgical option. However, progesterone (P4) resistance robs women of the option to choose hormone therapy to preserve their uterus. Therefore, developing nonsurgical treatments for endometrial cancer remains an essential goal for women who wish to maintain endometrial functions and women in high-risk surgical conditions. Mitogen-inducible gene 6 (MIG-6) acts as a tumor suppressor during endometrial tumorigenesis and as a P4 target gene in humans and mice. We developed mice with the conditional knockout of Mig-6 in all uterine compartments (Pgrcre/+Mig-6f/f; Mig-6KO) and endometrial epithelial cell-specific Mig-6 knockout (Sprr2fcre/+Mig-6f/f; Mig-6Ep-KO) mice. P4 treatment abated the development of endometrial hyperplasia and restored morphological and histological characteristics of the uterus of Mig-6Ep-KO mice, but Mig-6Ep-KO mice showed P4 resistance. P4 treatment reduced cell proliferation which was accompanied by decreased AKT signaling. In order to investigate the inhibition effect of AKT/mTOR signaling as non-surgical treatment on P4-resistant endometrial hyperplasia, we treated Mig-6KO and Mig-6Ep-KO mice with either: 1) vehicle (PBS); 2) MK-2206 (360 mg/kg, once a week); or 3) everolimus (10mg/kg daily) at 10 weeks old (n=6/treatment/genotype) for 1 month. MK-2206 has completed phase II trials and inhibits AKT phosphorylation. Everolimus is FDA-approved mTOR inhibitor. The vehicle group of Mig-6KO and Mig-6Ep-KO mice manifested the endometrial hyperplasia phenotype. In contrast, IHC analysis showed that the groups receiving MK-2206 or everolimus experienced significantly decreased AKT phosphorylation and phosphorylated S6 levels, respectively, and decreased epithelial proliferation, resulting in restoration of normal uterine histology. These data suggest that everolimus and MK-2206 may be new non-surgical treatment options for P4-resistant endometrial hyperplasia. This information may help guide more effective non-surgical interventions in the future. The project described was supported by Grant Number P50CA098258 from the National Cancer Institute. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health.

Citation Format: Tae Hoon Kim, Jae-Wook Jeong. Everolimus and MK-2206 reverse P4-resistant endometrial hyperplasia in Mig-6 mutant mice [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO041.

Endometrial epithelial ARID1A is critical for uterine gland function in early pregnancy establishment

Though endometriosis and infertility are clearly associated, the pathophysiological mechanism remains unclear. Previous work has linked endometrial ARID1A loss to endometriosis-related endometrial non-receptivity. Here, we show in mice that ARID1A binds and regulates transcription of the Foxa2 gene required for endometrial gland function. Uterine-specific deletion of Arid1a compromises gland development and diminishes Foxa2 and Lif expression. Deletion of Arid1a with Ltf-iCre in the adult mouse endometrial epithelium preserves the gland development while still compromising the gland function. Mice lacking endometrial epithelial Arid1a are severely sub-fertile due to defects in implantation, decidualization, and endometrial receptivity from disruption of the LIF-STAT3-EGR1 pathway. FOXA2 is also reduced in the endometrium of women with endometriosis in correlation with diminished ARID1A, and both ARID1A and FOXA2 are reduced in nonhuman primates induced with endometriosis. Our findings describe a role for ARID1A in the endometrial epithelium supporting early pregnancy establishment through the maintenance of gland function.

Animal Models of Adenomyosis

Adenomyosis is a nonmalignant uterine disorder in which endometrial tissue exists within and grows into the myometrium. Animal models have generated limited insight into the still-unclear pathogenesis of adenomyosis, provided a platform for preclinical screening of many drugs and compounds with potential as therapeutics, and elucidated mechanisms underlying the pain and fertility issues that occur in many women with the disease. Spontaneous adenomyosis has been studied in nonhuman primates, primarily in the form of case reports. Adenomyosis is routinely experimentally induced in mice through methods such as neonatal tamoxifen exposure, pituitary engraftment, and human tissue xenotransplantation. Several studies have also reported hormonal or environmental toxicant exposures that give rise to murine adenomyosis, and genetically engineered models have been created that recapitulate the human-like condition, most notably involving alteration of β-catenin expression. This review describes the animal models for adenomyosis and their contributions to our understanding of the factors underpinning the development of symptoms. Animal models represent a unique opportunity for understanding the molecular basis of adenomyosis and developing efficacious treatment options for affected women. Herein, we assess their different potentials and limitations with regard to identification of new therapeutic interventions and reflect on future directions for research and drug validation.

Abstract 428: The role of Mig-6 as a tumor suppressor in metastatic and recurrent endometrial cancer

Endometrial cancer is the most common gynecologic malignancy with an estimated 63,230 new cases in 2018. Although early-stage and low grade endometrioid endometrial cancers (EEC) generally exhibit a favorable prognosis, 10-15% of tumors recur within 5 years with poor treatment outcomes and low survival rates. Therefore, there is an urgent obligation to explore the mechanism of tumor metastasis and recurrence to further elucidate the progression of EEC. Mitogen inducible gene 6 (MIG-6) plays a tumor suppressor role in endometrial cancer. Ablation of Mig-6 in the murine uterus leads to the development of endometrial hyperplasia and E2-induced EEC. However, how MIG-6 suppresses tumorigenesis and metastasis in EEC is unclear. We have developed a genetically engineered mouse model for metastatic and recurrent EEC that implicates coexistent Pten and Mig-6 mutations in EEC. We also added a double-fluorescent Cre reporter to our EEC mouse model to distinguish EEC from surrounding normal tissues. In Pgrcre/+Rosa26mTmG mice, the Pgr-positive uterine cells express GFP, while Pgr-negative cells express membrane-targeted tandem dimer Tomato. The ablation of both Mig-6 and Pten in the uterus (Pgrcre/+Mig-6f/fPtenf/f; Mig-6d/dPtend/d) dramatically accelerated the development of EEC compared to single ablation of either gene. Importantly, Pten mutation is not sufficient for distant metastasis, but mice with concurrent ablation of Mig-6 and Pten develop distant metastasis. After hysterectomy at stage I of EEC, 62% of Mig-6d/dPtend/d mice (5/8) developed recurrence of EEC in the abdomen and lung. Cholesterol metabolism plays a significant role in cancer metastasis, and Mig-6 plays a critical role in the regulation of cholesterol homeostasis and bile acid synthesis. The ingenuity pathway analysis revealed that cholesterol biosynthesis was the most significantly changed pathway in the endometrial hyperplasia from 2-week-old Mig-6d/dPtend/d mice compared with Ptend/d mice. We found 67 and 18 significantly increased or decreased transcripts, respectively, that are related cholesterol biosynthesis. HMG-coA reductase inhibitors, commonly known as statins, account for the great majority of cholesterol-lowering drug use. However, little is known about the association between statin use and incidence of most types of cancers. To determine the effect of statins on tumorigenesis of EEC in Mig-6d/dPtend/d mice, the mutant mice were treated with atorvastatin (10mg/kg/day oral administration) or vehicle for 2 months. Treatment with statins significantly reduced development and progression of EEC in Mig-6d/dPtend/d mice compared to the vehicle group. Our results demonstrate that Mig-6 suppresses metastasis and recurrence in EEC with Pten mutation by inhibiting cholesterol biosynthesis. Research reported in this publication was supported by The Mary Kay Foundation 2019 research grant.

Citation Format: Tae Hoon Kim, Ryan M. Marquardt, Russell R. Broaddus, Jae-Wook Jeong. The role of Mig-6 as a tumor suppressor in metastatic and recurrent endometrial cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 428.

Interleukin-13 receptor subunit alpha-2 is a target of progesterone receptor and steroid receptor coactivator-1 in the mouse uterus†

The endometrium, composed of epithelial and stromal cell compartments, is tightly regulated by the ovarian steroid hormones estrogen (E2) and progesterone (P4) during early pregnancy. Through the progesterone receptor (PGR), steroid receptor coactivators, and other transcriptional coregulators, progesterone inhibits E2-induced cell proliferation and induces the differentiation of stromal cells in a process called decidualization to promote endometrial receptivity. Although interleukin-13 receptor subunit alpha-2 (Il13ra2) is expressed in the human and mouse endometrium, its potential role in the steroid hormone regulation of the endometrium has not been thoroughly examined. In this study, we employed PGR knockout mice and steroid receptor coactivator-1 knockout mice (SRC-1-/-) to profile the expression of Il13ra2 in the murine endometrium and determine the role of these transcriptional regulators in the hormone-responsiveness of Il13ra2 expression. Furthermore, we utilized a well-established decidualization-inducing steroidogenic cocktail and a siRNA-based knockdown of IL13RA2 to determine the importance of IL13RA2 in the decidualization of primary human endometrial stromal cells. Our findings demonstrate that Il13ra2 is expressed in the subepithelial stroma of the murine endometrium in response to ovarian steroid hormones and during early pregnancy in a PGR- and SRC-1-dependent manner. Furthermore, we show that knockdown of IL13RA2 before in vitro decidualization of primary human endometrial stromal cells partially compromises the full decidualization response. We conclude that Il13ra2 is a downstream target of progesterone through PGR and SRC-1 and plays a role in mediating the stromal action of ovarian steroid hormones.