Key Considerations for Studying the Effects of High-Fat Diet on the Nulligravid Mouse Endometrium.

The obesity epidemic continues to increase, with half of US women predicted to be obese by 2030. Women with obesity are at increased risk for not only cardiovascular and liver disease, but also reproductive disorders. Although mouse models are useful in studying the effects of obesity, there is inconsistency in obesity-induction methods, diet composition, and mouse strains, and studies using female mice are limited.

PIK3CA mutation in endometriotic epithelial cells promotes viperin-dependent inflammatory response to insulin.

Endometrial epithelia are known to harbor cancer driver mutations in the absence of any pathologies, including mutations in PIK3CA. Insulin plays an important role in regulating uterine metabolism during pregnancy, and hyperinsulinemia is associated with conditions impacting fertility. Hyperinsulinemia also promotes cancer, but the direct action of insulin on mutated endometrial epithelial cells is unknown.

Obesity alters the mouse endometrial transcriptome in a cell context-dependent manner.

Obesity impacts fertility and is positively correlated with endometrial hyperplasia and endometrial cancer occurrence. Endometrial epithelia often harbor disease driver-mutations, while endometrial stroma are highly regulative of neighboring epithelia. Here, we sought to determine distinct transcriptome changes occurring in individual cell types in the obese mouse uterus.

ARID1A-dependent maintenance of H3.3 is required for repressive CHD4-ZMYND8 chromatin interactions at super-enhancers.

Background: SWI/SNF (BAF) chromatin remodeling complexes regulate lineage-specific enhancer activity by promoting accessibility for diverse DNA-binding factors and chromatin regulators. Additionally, they are known to modulate the function of the epigenome through regulation of histone post-translational modifications and nucleosome composition, although the way SWI/SNF complexes govern the epigenome remains poorly understood. Here, we investigate the function of ARID1A, a subunit of certain mammalian SWI/SNF chromatin remodeling complexes associated with malignancies and benign diseases originating from the uterine endometrium.

Transcriptome and DNA methylome analyses reveal underlying mechanisms for the racial disparity in uterine fibroids.

Uterine fibroids (leiomyomas) affect Black women disproportionately compared with women of other races and ethnicities in terms of prevalence, incidence, and severity of symptoms. The causes of this racial disparity are essentially unknown. We hypothesized that myometria of Black women are more susceptible to developing fibroids, and we examined the transcriptomic and DNA methylation profiles of myometria and fibroids from Black and White women for comparison.

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.

AP-1 Subunit JUNB Promotes Invasive Phenotypes in Endometriosis.

Endometriosis is a disease defined by the presence of abnormal endometrium at ectopic sites, causing pain and infertility in 10% of women. Mutations in the chromatin remodeling protein ARID1A (AT-rich interactive domain-containing protein 1A) have been identified in endometriosis, particularly in the more severe deep infiltrating endometriosis and ovarian endometrioma subtypes. ARID1A has been shown to regulate chromatin at binding sites of the Activator Protein 1 (AP-1) transcription factor, and AP-1 expression has been shown in multiple endometriosis models.

SWI/SNF Antagonism of PRC2 Mediates Estrogen-Induced Progesterone Receptor Expression.

Endometrial cancer (EC) is characterized by high estrogen levels unopposed by progesterone. Treatment with progestins is standard for early EC, but the response to progestins is dependent on progesterone receptor (PGR) expression. Here, we show that the expression of PGR in endometrial epithelial cells is dependent on ARID1A, a DNA-binding subunit of the SWI/SNF chromatin-remodeling complex that is commonly mutated in EC.

Co-existing TP53 and ARID1A mutations promote aggressive endometrial tumorigenesis.

TP53 and ARID1A are frequently mutated across cancer but rarely in the same primary tumor. Endometrial cancer has the highest TP53-ARID1A mutual exclusivity rate. However, the functional relationship between TP53 and ARID1A mutations in the endometrium has not been elucidated.

ARID1A Mutations Promote P300-Dependent Endometrial Invasion through Super-Enhancer Hyperacetylation.

Endometriosis affects 1 in 10 women and is characterized by the presence of abnormal endometrium at ectopic sites. ARID1A mutations are observed in deeply invasive forms of the disease, often correlating with malignancy. To identify epigenetic dependencies driving invasion, we use an unbiased approach to map chromatin state transitions accompanying ARID1A loss in the endometrium.

SWI/SNF inactivation in the endometrial epithelium leads to loss of epithelial integrity.

Although ARID1A mutations are a hallmark feature, mutations in other SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling subunits are also observed in endometrial neoplasms. Here, we interrogated the roles of Brahma/SWI2-related gene 1 (BRG1, SMARCA4), the SWI/SNF catalytic subunit, in the endometrial epithelium. BRG1 loss affects more than one-third of all active genes and highly overlaps with the ARID1A gene regulatory network.

Lgr5-positive endothelial progenitor cells occupy a tumor and injury prone niche in the kidney vasa recta.

The Wnt pathway co-receptor, Leucine Rich Repeat Containing G Protein-Coupled Receptor 5 (LGR5), labels tumor-prone stem cell populations in certain types of tissue. In this study, we show that ARID1A and PIK3CA mutations in LGR5 cells result in renal angiosarcomas in adult mice. The tumors originate in the renal medulla.

ATAC-seq normalization method can significantly affect differential accessibility analysis and interpretation.

Background: Chromatin dysregulation is associated with developmental disorders and cancer. Numerous methods for measuring genome-wide chromatin accessibility have been developed in the genomic era to interrogate the function of chromatin regulators. A recent technique which has gained widespread use due to speed and low input requirements with native chromatin is the Assay for Transposase-Accessible Chromatin, or ATAC-seq.

A mouse model of endometriosis mimicking the natural spread of invasive endometrium.

Study Question: Is it possible to establish a genetically engineered mouse model (GEMM) of endometriosis that mimics the natural spread of invasive endometrium?

Summary Answer: Endometriosis occurs in an ARID1A (AT-rich interactive domain-containing protein 1A) and PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha) mutant GEMM of endometrial dysfunction following salpingectomy.

What Is Known Already: Although mouse models of endometriosis have long been established, most models rely on intraperitoneal injection of uterine fragments, steroid hormone treatments or the use of immune-compromised mice.

Study Design, Size, Duration: Mice harboring the lactotransferrin-Cre (LtfCre0/+), Arid1afl, (Gt)R26Pik3ca*H1047R and (Gt)R26mTmG alleles were subject to unilateral salpingectomies at 6 weeks of age.

ARID1A and PI3-kinase pathway mutations in the endometrium drive epithelial transdifferentiation and collective invasion.

ARID1A and PI3-Kinase (PI3K) pathway alterations are common in neoplasms originating from the uterine endometrium. Here we show that monoallelic loss of ARID1A in the mouse endometrial epithelium is sufficient for vaginal bleeding when combined with PI3K activation. Sorted mutant epithelial cells display gene expression and promoter chromatin signatures associated with epithelial-to-mesenchymal transition (EMT).

The SWI/SNF BAF-A complex is essential for neural crest development.

Growing evidence indicates that chromatin remodeler mutations underlie the pathogenesis of human neurocristopathies or disorders that affect neural crest cells (NCCs). However, causal relationships among chromatin remodeler subunit mutations and NCC defects remain poorly understood. Here we show that homozygous loss of ARID1A-containing, SWI/SNF chromatin remodeling complexes (BAF-A) in NCCs results in embryonic lethality in mice, with mutant embryos succumbing to heart defects.

Global gene expression profiling of a mouse model of ovarian clear cell carcinoma caused by ARID1A and PIK3CA mutations implicates a role for inflammatory cytokine signaling.

Ovarian clear-cell carcinoma (OCCC) is an aggressive form of epithelial ovarian cancer (EOC). OCCC represents 5-25% of all EOC incidences and is the second leading cause of death from ovarian cancer (Glasspool and McNeish, 2013) [1]. A recent publication by Chandler et al.

Coexistent ARID1A-PIK3CA mutations promote ovarian clear-cell tumorigenesis through pro-tumorigenic inflammatory cytokine signalling.

Ovarian clear-cell carcinoma (OCCC) is an aggressive form of ovarian cancer with high ARID1A mutation rates. Here we present a mutant mouse model of OCCC. We find that ARID1A inactivation is not sufficient for tumour formation, but requires concurrent activation of the phosphoinositide 3-kinase catalytic subunit, PIK3CA.

Characterization of a Brg1 hypomorphic allele demonstrates that genetic and biochemical activity are tightly correlated.

Mammalian SWI/SNF-related complexes are recruited to the promoters of numerous target genes, and the BRG1 catalytic subunit confers ATPase activity necessary to slide or evict nucleosomes and to regulate transcription. Based on gene-targeting experiments in mice, BRG1 is essential for early embryonic development. However, Brg1 null mutants have provided limited insight into gene-dosage considerations and structure-function relationships.

Joint TGF-β type II receptor-expressing cells: ontogeny and characterization as joint progenitors.

TGF-β type II receptor (Tgfbr2) signaling plays an essential role in joint-element development. The Tgfbr2(PRX-1KO) mouse, in which the Tgfbr2 is conditionally inactivated in developing limbs, lacks interphalangeal joints and tendons. In this study, we used the Tgfbr2-β-Gal-GFP-BAC mouse as a LacZ/green fluorescent protein (GFP)-based read-out to determine: the spatial and temporally regulated expression pattern of Tgfbr2-expressing cells within joint elements; their expression profile; and their slow-cycling labeling with bromodeoxyuridine (BrdU).

Acute BMP2 upregulation following induction of ischemic osteonecrosis in immature femoral head.

Juvenile ischemic osteonecrosis of the femoral head (IOFH) is one of the most serious hip conditions causing the femoral head deformity. Little is known about BMP signaling following ischemic osteonecrosis. In this study, we found acute BMP2 upregulation in the femoral head cartilage 24h after ischemic induction using our immature pig IOFH model.

ARID1a-DNA interactions are required for promoter occupancy by SWI/SNF.

Every known SWI/SNF chromatin-remodeling complex incorporates an ARID DNA binding domain-containing subunit. Despite being a ubiquitous component of the complex, physiological roles for this domain remain undefined. Here, we show that disruption of ARID1a-DNA binding in mice results in embryonic lethality, with mutant embryos manifesting prominent defects in the heart and extraembryonic vasculature.

Repressive BMP2 gene regulatory elements near the BMP2 promoter.

The level of bone morphogenetic protein 2 (BMP2) profoundly influences essential cell behaviors such as proliferation, differentiation, apoptosis, and migration. The spatial and temporal pattern of BMP2 synthesis, particular in diverse embryonic cells, is highly varied and dynamic. We have identified GC-rich sequences within the BMP2 promoter region that strongly repress gene expression.

Bmp2 and Bmp4 exert opposing effects in hypoxic pulmonary hypertension.

The bone morphogenetic protein (BMP) type 2 receptor ligand, Bmp2, is upregulated in the peripheral pulmonary vasculature during hypoxia-induced pulmonary hypertension (PH). This contrasts with the expression of Bmp4, which is expressed in respiratory epithelia throughout the lung. Unlike heterozygous null Bmp4 mice (Bmp4(LacZ/+)), which are protected from the development of hypoxic PH, mice that are heterozygous null for Bmp2 (Bmp2(+/-)) develop more severe hypoxic PH than their wild-type littermates.

Identification of an ancient Bmp4 mesoderm enhancer located 46 kb from the promoter.

Bone morphogenetic protein 4 (Bmp4) is a multi-functional, developmentally regulated gene that is essential for mouse development, as most Bmp4-null mouse embryos die at the onset of gastrulation and fail to develop mesoderm. Little is known about the transcriptional regulation of Bmp4. To identify potential long-range cis-regulatory elements that direct its complex spatiotemporal expression patterns, we surveyed the mouse Bmp4 locus using two overlapping bacterial artificial chromosome (BAC) reporter transgenes.