Generation of salivary glands derived from pluripotent stem cells via conditional blastocyst complementation.

Whole salivary gland generation and transplantation offer potential therapies for salivary gland dysfunction. However, the specific lineage required to engineer complete salivary glands has remained elusive. In this study, we identify the Foxa2 lineage as a critical lineage for salivary gland development through conditional blastocyst complementation (CBC). Foxa2 lineage marking begins at the boundary between the endodermal and ectodermal regions of the oral epithelium before the formation of the primordial salivary gland, thereby labeling the entire gland. Ablation of Fgfr2 within the Foxa2 lineage in mice leads to salivary gland agenesis. We reversed this phenotype by injecting donor pluripotent stem cells into the mouse blastocysts, resulting in mice that survived to adulthood with salivary glands of normal size, comparable to those of their littermate controls. These findings demonstrate that CBC-based salivary gland regeneration serves as a foundational experimental approach for future advanced cell-based therapies.

A single-cell atlas of pig gastrulation as a resource for comparative embryology.

Cell-fate decisions during mammalian gastrulation are poorly understood outside of rodent embryos. The embryonic disc of pig embryos mirrors humans, making them a useful proxy for studying gastrulation. Here we present a single-cell transcriptomic atlas of pig gastrulation, revealing cell-fate emergence dynamics, as well as conserved and divergent gene programs governing early porcine, primate, and murine development. We highlight heterochronicity in extraembryonic cell-types, despite the broad conservation of cell-type-specific transcriptional programs. We apply these findings in combination with functional investigations, to outline conserved spatial, molecular, and temporal events during definitive endoderm specification. We find early FOXA2 + /TBXT- embryonic disc cells directly form definitive endoderm, contrasting later-emerging FOXA2/TBXT+ node/notochord progenitors. Unlike mesoderm, none of these progenitors undergo epithelial-to-mesenchymal transition. Endoderm/Node fate hinges on balanced WNT and hypoblast-derived NODAL, which is extinguished upon endodermal differentiation. These findings emphasise the interplay between temporal and topological signalling in fate determination during gastrulation.

MCTP1 increases the malignancy of androgen-deprived prostate cancer cells by inducing neuroendocrine differentiation and EMT.

Neuroendocrine prostate cancer (PCa) (NEPC), an aggressive subtype that is associated with poor prognosis, may arise after androgen deprivation therapy (ADT). We investigated the molecular mechanisms by which ADT induces neuroendocrine differentiation in advanced PCa. We found that transmembrane protein 1 (MCTP1), which has putative Ca2+ sensing function and multiple Ca2+-binding C2 domains, was abundant in samples from patients with advanced PCa. MCTP1 was associated with the expression of the EMT-associated transcription factors ZBTB46, FOXA2, and HIF1A. The increased abundance of MCTP1 promoted PC3 prostate cancer cell migration and neuroendocrine differentiation and was associated with SNAI1-dependent EMT in C4-2 PCa cells after ADT. ZBTB46 interacted with FOXA2 and HIF1A and increased the abundance of MCTP1 in a hypoxia-dependent manner. MCTP1 stimulated Ca2+ signaling and AKT activation to promote EMT and neuroendocrine differentiation by increasing the SNAI1-dependent expression of EMT and neuroendocrine markers, effects that were blocked by knockdown of MCTP1. These data suggest an oncogenic role for MCTP1 in the maintenance of a rare and aggressive prostate cancer subtype through its response to Ca2+ and suggest its potential as a therapeutic target.

FOXA2 rewires AP-1 for transcriptional reprogramming and lineage plasticity in prostate cancer.

FOXA family proteins act as pioneer factors by remodeling compact chromatin structures. FOXA1 is crucial for the chromatin binding of the androgen receptor (AR) in both normal prostate epithelial cells and the luminal subtype of prostate cancer (PCa). Recent studies have highlighted the emergence of FOXA2 as an adaptive response to AR signaling inhibition treatments. However, the role of the FOXA1 to FOXA2 transition in regulating cancer lineage plasticity remains unclear. Our study demonstrates that FOXA2 binds to distinct classes of developmental enhancers in multiple AR-independent PCa subtypes, with its binding depending on LSD1. Moreover, we reveal that FOXA2 collaborates with JUN at chromatin and promotes transcriptional reprogramming of AP-1 in lineage-plastic cancer cells, thereby facilitating cell state transitions to multiple lineages. Overall, our findings underscore the pivotal role of FOXA2 as a pan-plasticity driver that rewires AP-1 to induce the differential transcriptional reprogramming necessary for cancer cell lineage plasticity.

Establishment of Induced Pancreatic Stem Cells by Yes-Associated Protein 1.

Recently, we and others generated induced tissue-specific stem/progenitor (iTS/iTP) cells. The advantages of iTS/iTP cells compared with induced pluripotent stem (iPS) cells are (1) easier generation, (2) efficient differentiation, and (3) no teratomas formation. In this study, we generated mouse induced pancreatic stem cells (iTS-P cells) by the plasmid vector expressing Yes-associated protein 1 (YAP). The iTS-P YAP9 cells expressed Foxa2 (endoderm marker) and Pdx1 (pancreatic marker) while the expressions of Oct3/4 and Nanog (marker of embryonic stem [ES] cells) in iTS-P YAP9 cells was significantly lower compared with those in ES cells. The iTS-P YAP9 cells efficiently differentiated into insulin-expressing cells compared with ES cells. The ability to generate autologous iTS cells may be applied to diverse applications of regenerative medicine.

Mouse neural tube organoids self-organize floorplate through BMP-mediated cluster competition.

During neural tube (NT) development, the notochord induces an organizer, the floorplate, which secretes Sonic Hedgehog (SHH) to pattern neural progenitors. Conversely, NT organoids (NTOs) from embryonic stem cells (ESCs) spontaneously form floorplates without the notochord, demonstrating that stem cells can self-organize without embryonic inducers. Here, we investigated floorplate self-organization in clonal mouse NTOs. Expression of the floorplate marker FOXA2 was initially spatially scattered before resolving into multiple clusters, which underwent competition and sorting, resulting in a stable "winning" floorplate. We identified that BMP signaling governed long-range cluster competition. FOXA2+ clusters expressed BMP4, suppressing FOXA2 in receiving cells while simultaneously expressing the BMP-inhibitor NOGGIN, promoting cluster persistence. Noggin mutation perturbed floorplate formation in NTOs and in the NT in vivo at mid/hindbrain regions, demonstrating how the floorplate can form autonomously without the notochord. Identifying the pathways governing organizer self-organization is critical for harnessing the developmental plasticity of stem cells in tissue engineering.

Chromosome 20p11.2 deletions cause congenital hyperinsulinism via the loss of FOXA2 or its regulatory elements.

Persistent congenital hyperinsulinism (HI) is a rare genetically heterogeneous condition characterised by dysregulated insulin secretion leading to life-threatening hypoglycaemia. For up to 50% of affected individuals screening of the known HI genes does not identify a disease-causing variant. Large deletions have previously been used to identify novel regulatory regions causing HI. Here, we used genome sequencing to search for novel large (>1 Mb) deletions in 180 probands with HI of unknown cause and replicated our findings in a large cohort of 883 genetically unsolved individuals with HI using off-target copy number variant calling from targeted gene panels. We identified overlapping heterozygous deletions in five individuals (range 3-8 Mb) spanning chromosome 20p11.2. The pancreatic beta-cell transcription factor gene, FOXA2, a known cause of HI was deleted in two of the five individuals. In the remaining three, we found a minimal deleted region of 2.4 Mb adjacent to FOXA2 that encompasses multiple non-coding regulatory elements that are in conformational contact with FOXA2. Our data suggests that the deletions in these three children may cause disease through the dysregulation of FOXA2 expression. These findings provide new insights into the regulation of FOXA2 in the beta-cell and confirm an aetiological role for chromosome 20p11.2 deletions in syndromic HI.

Pioneer Factor Foxa2 Mediates Chromatin Conformation Changes for Activation of Bile Acid Targets of FXR.

BACKGROUND & AIMS: Transcription factors regulate gene expression that orchestrates liver physiology. Many bind at distal enhancers and chromatin looping is required to activate their targets. Chromatin architecture has been linked to essential functions of the liver, including metabolism and sexually dimorphic gene expression. We have previously shown that pioneer factor Foxa2 opens chromatin for binding of nuclear receptors farnesoid X receptor (FXR) and liver X receptor-α during acute ligand activation. FXR is activated by bile acids and deletion of Foxa2 in the liver results in intrahepatic cholestasis. We hypothesized that Foxa2 also enables chromatin conformational changes during ligand activation and performed genome-wide studies to test this hypothesis. METHODS: We performed Foxa2 HiChIP (Hi-C and ChIP) to assess Foxa2-dependent long-range interactions in mouse livers treated with either vehicle control or FXR agonist GW4064. RESULTS: HiChIP contact analysis shows that global chromatin interactions are dramatically increased during FXR activation. Ligand-treated livers exhibit extensive redistribution of topological associated domains and substantial increase in Foxa2-anchored loops, suggesting Foxa2 is involved in dynamic chromatin conformational changes. We demonstrate that chromatin conformation, including genome-wide interactions, topological associated domains, and intrachromosomal and interchromosomal Foxa2-anchored loops, drastically changes on addition of FXR agonist. Additional Foxa2 binding in ligand-activated state leads to formation of Foxa2-anchored loops, leading to distal interactions and activation of gene expression of FXR targets. CONCLUSIONS: Ligand activation of FXR, and likely of related receptors, requires global changes in chromatin architecture. We determine a novel role for Foxa2 in enabling these conformational changes, extending its function in bile acid metabolism.

CK1α deficiency impairs mouse uterine adenogenesis by inducing epithelial cell apoptosis through GSK3ß pathway and inhibiting Foxa2 expression through p53 pathway†.

Uterine glands and their secretions are crucial for conceptus survival and implantation in rodents and humans. In mice, the development of uterine gland known as adenogenesis occurs after birth, whereas the adenogenesis in humans initiates from fetal life and completed at puberty. Uterine adenogenesis involves dynamic epithelial cell proliferation, differentiation, and apoptosis. However, it is largely unexplored about the mechanisms governing adenogenesis. CK1α plays important roles in regulating cell division, differentiation, and death, but it is unknown whether CK1α affects adenogenesis. In the current study, uterus-specific CK1α knockout female mice (Csnk1a1d/d) were infertile resulted from lack of uterine glands. Subsequent analysis revealed that CK1α deletion induced massive apoptosis in uterine epithelium by activating GSK3ß, which was confirmed by injections of GSK3ß inhibitor SB216763 to Csnk1a1d/d females, and the co-treatment of SB216763 and CK1 inhibitor d4476 on cultured epithelial cells. Another important finding was that our results revealed CK1α deficiency activated p53, which then blocked the expression of Foxa2, an important factor for glandular epithelium development and function. This was confirmed by that Foxa2 expression level was elevated in p53 inhibitor pifithrin-α injected Csnk1a1d/d mouse uterus and in vitro dual-luciferase reporter assay between p53 and Foxa2. Collectively, these studies reveal that CK1α is a novel factor regulating uterine adenogenesis by inhibiting epithelial cell apoptosis through GSK3ß pathway and regulating Foxa2 expression through p53 pathway. Uncovering the mechanisms of uterine adenogenesis is expected to improve pregnancy success in humans and other mammals.

FOXA2 activates HIF2α expression to promote tumor progression and is regulated by the E3 ubiquitin ligase VHL in renal cell carcinoma.

Renal cell carcinoma (RCC) is a frequent malignancy of the urinary system with high mortality and morbidity. However, the molecular mechanisms underlying RCC progression are still largely unknown. In this study, we identified FOXA2, a pioneer transcription factor, as a driver oncogene for RCC. We show that FOXA2 was commonly upregulated in human RCC samples and promoted RCC proliferation, as evidenced by assays of cell viability, colony formation, migratory and invasive capabilities, and stemness properties. Mechanistically, we found that FOXA2 promoted RCC cell proliferation by transcriptionally activating HIF2α expression in vitro and in vivo. Furthermore, we found that FOXA2 could interact with VHL (von Hippel‒Lindau), which ubiquitinated FOXA2 and controlled its protein stability in RCC cells. We showed that mutation of lysine at position 264 to arginine in FOXA2 could mostly abrogate its ubiquitination, augment its activation effect on HIF2α expression, and promote RCC proliferation in vitro and RCC progression in vivo. Importantly, elevated expression of FOXA2 in patients with RCC positively correlated with the expression of HIF2α and was associated with shorter overall and disease-free survival. Together, these findings reveal a novel role of FOXA2 in RCC development and provide insights into the underlying molecular mechanisms of FOXA2-driven pathological processes in RCC.

FOXA2 suppresses gallbladder carcinoma cell migration, invasion, and epithelial-mesenchymal transition by targeting SERPINB5.

BACKGROUND: Gallbladder cancer (GBC), a highly malignant gastrointestinal tumor, lacks effective therapies. Foxhead box A2 (FOXA2) is a tumor suppressor that is poorly expressed in various human malignancies. This study aimed to ascertain FOXA2 expression in GBC and its relevance to tumor metastasis, and to elucidate its regulatory mechanism with epithelial-mesenchymal transition (EMT) as an entry point, in the hope of providing a potential therapeutic target for GBC. METHODS: FOXA2 expression in GBC tissues was first detected using immunohistochemistry (IHC), followed by correlation analysis with clinicopathological characteristics and survival prognosis. Subsequently, the effects of FOXA2 on GBC cell migration and invasion, as well as EMT induction, were evaluated by scratch, Transwell, RT-PCR, and Western blot assays, together with animal experimentation. Ultimately, mRNA sequencing was carried out to identify the key downstream target genes of FOXA2 in controlling the EMT process in GBC cells, and dual-luciferase reporter and chromatin immunoprecipitation assays were used to determine its regulatory mechanism. RESULTS: FOXA2 was underexpressed in GBC tissues and inversely correlated with tumor node metastasis stage, lymph node metastasis, and poor patient prognosis. FOXA2 exerts suppressive effects on EMT and metastasis of GBC in vivo and in vitro. FOXA2 can impede GBC cell migratory and invasive functions and EMT by positively mediating serine protein kinase inhibitor B5 (SERPINB5) expression. CONCLUSION: FOXA2 directly binds to the SERPINB5 promoter region to stimulate its transcription, thereby modulating the migration and invasion behaviors of GBC cells as well as the EMT process, which might be an effective therapeutic target against GBC.

SENP1 knockdown-mediated CTCF SUMOylation enhanced its stability and alleviated lipopolysaccharide-evoked inflammatory injury in human lung fibroblasts via regulation of FOXA2 transcription.

BACKGROUND: Excessive inflammation is the main cause of treatment failure in neonatal pneumonia (NP). CCCTC-binding factor (CTCF) represents an important node in various inflammatory diseases. In the present study, we tried to clarify the function and underlying molecular mechanism of CTCF on an in vitro cellular model of NP, which was generated by simulating the human lung fibroblast cell line WI-38 with lipopolysaccharide (LPS). METHODS: The SUMOylation level and protein interaction were verified by Co-immunoprecipitation assay. Cell viability was measured by Cell Counting Kit-8 assay. Inflammatory factors were examined by Enzyme-linked immunosorbent assay. Cell apoptosis was evaluated by TUNEL assay. The binding activity of CTCF to target promoter was tested by chromatin immunoprecipitation and luciferase reporter assay. RESULTS: LPS treatment restrained cell viability, promoted the production of inflammatory factors, and enhanced cell apoptosis. CTCF overexpression played anti-inflammatory and anti-apoptotic roles. Furthermore, CTCF was modified by SUMOylation with small ubiquitin-like modifier protein 1 (SUMO1). Interfering with sumo-specific protease 1 (SENP1) facilitated CTCF SUMOylation and protein stability, thus suppressing LPS-evoked inflammatory and apoptotic injuries. Moreover, CTCF could bind to the forkhead box protein A2 (FOXA2) promoter region to promote FOXA2 expression. The anti-inflammatory and anti-apoptotic roles of CTCF are associated with FOXA2 activation. In addition, SENP1 knockdown increased FOXA2 expression by enhancing the abundance and binding ability of CTCF. CONCLUSIONS: SUMOylation of CTCF by SENP1 knockdown enhanced its protein stability and binding ability and it further alleviated LPS-evoked inflammatory injury in human lung fibroblasts by positively regulating FOXA2 transcription.

FXR controls insulin content by regulating Foxa2-mediated insulin transcription.

Farnesoid X receptor (FXR) is a nuclear ligand-activated receptor of bile acids that plays a role in the modulation of insulin content. However, the underlying molecular mechanisms remain unclear. Forkhead box a2 (Foxa2) is an important nuclear transcription factor in pancreatic ß-cells and is involved in ß-cell function. We aimed to explore the signaling mechanism downstream of FXR to regulate insulin content and underscore its association with Foxa2 and insulin gene (Ins) transcription. All experiments were conducted on FXR transgenic mice, INS-1 823/13 cells, and diabetic Goto-Kakizaki (GK) rats undergoing sham or Roux-en-Y gastric bypass (RYGB) surgery. Islets from FXR knockout mice and INS-1823/13 cells with FXR knockdown exhibited substantially lower insulin levels than that of controls. This was accompanied by decreased Foxa2 expression and Ins transcription. Conversely, FXR overexpression increased insulin content, concomitant with enhanced Foxa2 expression and Ins transcription in INS-1 823/13 cells. Moreover, FXR knockdown reduced FXR recruitment and H3K27 trimethylation in the Foxa2 promoter. Importantly, Foxa2 overexpression abrogated the adverse effects of FXR knockdown on Ins transcription and insulin content in INS-1 823/13 cells. Notably, RYGB surgery led to improved insulin content in diabetic GK rats, which was accompanied by upregulated FXR and Foxa2 expression and Ins transcription. Collectively, these data suggest that Foxa2 serves as the target gene of FXR in ß-cells and mediates FXR-enhanced Ins transcription. Additionally, the upregulated FXR/Foxa2 signaling cascade could contribute to the enhanced insulin content in diabetic GK rats after RYGB.

Analysis of GATA3 and FOXA2 expression suggests that downregulation of genes involved in the maintenance of a mature yolk sac tumor phenotype may underlie sarcomatoid transformation.

In the post-chemotherapy setting, germ cell tumors of the testis (GCTT) that resemble non-specific sarcomas and co-express cytokeratins and glypican-3 (GPC3) are diagnosed as "sarcomatoid yolk sac tumor postpubertal-type (YSTpt)". The diagnosis of sarcomatoid YSTpt is clinically relevant but challenging due to its rarity, non-specific histology, and negative α-fetoprotein (AFP) staining. Recently, FOXA2 has emerged as a key-gene in the reprogramming of GCTT (activating the transcription of several genes, among which GATA3), and immunohistochemical studies showed that GATA3 and FOXA2 have a higher sensitivity for non-sarcomatoid YSTpt than GPC3 and AFP. We found that sarcomatoid YSTpt did not express FOXA2 [0: 14/14 (100%)] and showed focal expression of GATA3 [0: 12/14 (85.7%), 1 + : 2/14 (14.3%)], thus suggesting that these markers are not useful in diagnosing this tumor. Furthermore, we proposed a potential mechanism of sarcomatoid transformation in the post-chemotherapy setting of GCTT, mediated by the downregulation of FOXA2 and GATA3.

Conditional blastocyst complementation of a defective Foxa2 lineage efficiently promotes the generation of the whole lung.

Millions suffer from incurable lung diseases, and the donor lung shortage hampers organ transplants. Generating the whole organ in conjunction with the thymus is a significant milestone for organ transplantation because the thymus is the central organ to educate immune cells. Using lineage-tracing mice and human pluripotent stem cell (PSC)-derived lung-directed differentiation, we revealed that gastrulating Foxa2 lineage contributed to both lung mesenchyme and epithelium formation. Interestingly, Foxa2 lineage-derived cells in the lung mesenchyme progressively increased and occupied more than half of the mesenchyme niche, including endothelial cells, during lung development. Foxa2 promoter-driven, conditional Fgfr2 gene depletion caused the lung and thymus agenesis phenotype in mice. Wild-type donor mouse PSCs injected into their blastocysts rescued this phenotype by complementing the Fgfr2-defective niche in the lung epithelium and mesenchyme and thymic epithelium. Donor cell is shown to replace the entire lung epithelial and robust mesenchymal niche during lung development, efficiently complementing the nearly entire lung niche. Importantly, those mice survived until adulthood with normal lung function. These results suggest that our Foxa2 lineage-based model is unique for the progressive mobilization of donor cells into both epithelial and mesenchymal lung niches and thymus generation, which can provide critical insights into studying lung transplantation post-transplantation shortly.

Uncovering the role of FOXA2 in the Development of Human Serotonin Neurons.

Directed differentiation of serotonin neurons (SNs) from human pluripotent stem cells (hPSCs) provides a valuable tool for uncovering the mechanism of human SN development and the associated neuropsychiatric disorders. Previous studies report that FOXA2 is expressed by serotonergic progenitors (SNPs) and functioned as a serotonergic fate determinant in mouse. However, in the routine differentiation experiments, it is accidentally found that less SNs and more non-neuronal cells are obtained from SNP stage with higher percentage of FOXA2-positive cells. This phenomenon prompted them to question the role of FOXA2 as an intrinsic fate determinant for human SN differentiation. Herein, by direct differentiation of engineered hPSCs into SNs, it is found that the SNs are not derived from FOXA2-lineage cells; FOXA2-knockout hPSCs can still differentiate into mature and functional SNs with typical serotonergic identity; FOXA2 overexpression suppresses the SN differentiation, indicating that FOXA2 is not intrinsically required for human SN differentiation. Furthermore, repressing FOXA2 expression by retinoic acid (RA) and dynamically modulating Sonic Hedgehog (SHH) signaling pathway promotes human SN differentiation. This study uncovers the role of FOXA2 in human SN development and improves the differentiation efficiency of hPSCs into SNs by repressing FOXA2 expression.

PIAS1 upregulation confers protection against Cerulein-induced acute pancreatitis via FTO downregulation by enhancing sumoylation of Foxa2.

OBJECTIVE: This research discussed the specific mechanism by which PIAS1 affects acute pancreatitis (AP). METHODS: PIAS1, Foxa2, and FTO expression was assessed in Cerulein-induced AR42J cells and mice. Loss- and gain-of-function assays and Cerulein induction were conducted in AR42J cells and mice for analysis. The relationship among PIAS1, Foxa2, and FTO was tested. Cell experiments run in triplicate, and eight mice for each animal group. RESULTS: Cerulein-induced AP cells and mice had low PIAS1 and Foxa2 and high FTO. Cerulein induced pancreatic injury in mice and inflammation and oxidative stress in pancreatic tissues, which could be reversed by PIAS1 or Foxa2 upregulation or FTO downregulation. PIAS1 elevated SUMO modification of Foxa2 to repress FTO transcription. FTO upregulation neutralized the ameliorative effects of PIAS1 or Foxa2 upregulation on Cerulein-induced AR42J cell injury, inflammation, and oxidative stress. CONCLUSION: PIAS1 upregulation diminished FTO transcription by increasing Foxa2 SUMO modification, thereby ameliorating Cerulein-induced AP.

FOXA2 suppresses PKM2 transcription and affects the Wnt/ß-catenin activity to block aerobic glycolysis in thyroid carcinoma.

Aerobic glycolysis is critical for the energy metabolism of cancer cells. This study focuses on the regulation of forkhead box A2 (FOXA2) on pyruvate kinase M2 (PKM2) and their effects on the glycolytic activity and malignant phenotype of thyroid carcinoma (THCA) cells. By analysing four Gene Expression Omnibus datasets and querying bioinformatics systems, we obtained FOXA2 as a poorly expressed transcription factor in THCA. Later, we validated decreased mRNA and protein levels of FOXA2 in THCA cells by quantitative polymerase chain reaction and western blot assays. FOXA2 upregulation in THCA cells suppressed the glucose uptake and lactate production, and it reduced the extracellular acidification rate, but increased the oxygen consumption rate of cells. Meanwhile, the FOXA2 overexpression blocked the proliferation and mobility, and the tumourigenic activity of cancer cells. The chromatin immunoprecipitation and luciferase assays showed that FOXA2 bound to PKM2 promoter and suppressed the transcription of PKM2, which was highly expressed in THCA cells. Further upregulation of PKM2 elevated the ß-catenin, c-Myc and cyclin D1 levels and restored the glycolytic activity as well as the malignant properties of cancer cells. Collectively, this work reveals that FOXA2 suppresses aerobic glycolysis and progression of THCA by blocking PKM2 transcription and inactivating the Wnt/ß-catenin pathway.

FoxA2 represses ERß-mediated pyroptosis in endometriosis by transcriptionally inhibiting IGF2BP1.

BACKGROUND: Endometriosis is a severe disease which is associated with excessive activation of pyroptosis. Our present research aimed to investigate the function of Forkhead Box A2 (FoxA2) in regulating pyroptosis in endometriosis. METHODS: IL-1ß and IL-18 concentrations were assessed using ELISA. Cell pyroptosis was analyzed using flow cytometry. TUNEL staining was performed to determine human endometrial stromal cells (HESC) death. Moreover, ERß mRNA stability was assessed using RNA degradation assay. Finally, the binding relationships between FoxA2, IGF2BP1 and ERß were verified by dual-luciferase reporter system, ChIP, RIP and RNA pull-down assays. RESULTS: Our results revealed that IGF2BP1 and ERß were significantly upregulated in ectopic endometrium (EC) tissues of endometriosis patients compared to that in eutopic endometrium (EU) tissues as well as IL-18 and IL-1ß levels. Loss-of-function experiments subsequently demonstrated that either IGF2BP1 knockdown or ERß knockdown could repress HESC pyroptosis. In addition, IGF2BP1 upregulation promoted the pyroptosis in endometriosis by binding to ERß and promoting ERß mRNA stability. Our further research displayed that FoxA2 upregulation suppressed HESC pyroptosis by interacting with IGF2BP1 promoter. CONCLUSION: Our research proved that FoxA2 upregulation downregulated ERß by transcriptionally inhibiting IGF2BP1, thereby repressing pyroptosis in endometriosis.

Upregulation of FOXA2 in uterine luminal epithelium and vaginal basal epithelium of epiERα-/- (Esr1fl/flWnt7aCre/+) mice†.

Forkhead box protein A2 (FOXA2) is a pioneer transcription factor important for epithelial budding and morphogenesis in different organs. It has been used as a specific marker for uterine glandular epithelial cells (GE). FOXA2 has close interactions with estrogen receptor α (ERα). ERα binding to Foxa2 gene in the uterus indicates its regulation of Foxa2. The intimate interactions between ERα and FOXA2 and their essential roles in early pregnancy led us to investigate the expression of FOXA2 in the female reproductive tract of pre-implantation epiERα-/- (Esr1fl/flWnt7aCre/+) mice, in which ERα is conditionally deleted in the epithelium of reproductive tract. In the oviduct, FOXA2 is detected in the ciliated epithelial cells of ampulla but absent in the isthmus of day 3.5 post-coitum (D3.5) Esr1fl/fl control and epiERα-/- mice. In the uterus, FOXA2 expression in the GE appears to be comparable between Esr1fl/fl and epiERα-/- mice. However, FOXA2 is upregulated in the D0.5 and D3.5 but not PND25-28 epiERα-/- uterine luminal epithelial cells (LE). In the vagina, FOXA2 expression is low in the basal layer and increases toward the superficial layer of the D3.5 Esr1fl/fl vaginal epithelium, but FOXA2 is detected in the basal, intermediate, and superficial layers, with the strongest FOXA2 expression in the intermediate layers of the D3.5 epiERα-/- vaginal epithelium. This study demonstrates that loss of ERα in LE and vaginal basal layer upregulates FOXA2 expression in these epithelial cells during early pregnancy. The mechanisms for epithelial cell-type specific regulation of FOXA2 by ERα remain to be elucidated.