PAX8: A Highly Sensitive Marker for the Glands in Extragenital Endometriosis

Lysine acetyltransferase 14 mediates TGF-β-induced fibrosis in ovarian endometrioma via co-operation with serum response factor

BACKGROUND

Fibrogenesis within ovarian endometrioma (endometrioma), mainly induced by transforming growth factor-β (TGF-β), is characterized by myofibroblast over-activation and excessive extracellular matrix (ECM) deposition, contributing to endometrioma-associated symptoms such as infertility by impairing ovarian reserve and oocyte quality. However, the precise molecular mechanisms that underpin the endometrioma- associated fibrosis progression induced by TGF-β remain poorly understood.

METHODS

The expression level of lysine acetyltransferase 14 (KAT14) was validated in endometrium biopsies from patients with endometrioma and healthy controls, and the transcription level of KAT14 was further confirmed by analyzing a published single-cell transcriptome (scRNA-seq) dataset of endometriosis. We used overexpression, knockout, and knockdown approaches in immortalized human endometrial stromal cells (HESCs) or human primary ectopic endometrial stromal cells (EcESCs) to determine the role of KAT14 in TGF-β-induced fibrosis. Furthermore, an adeno-associated virus (AAV) carrying KAT14-shRNA was used in an endometriosis mice model to assess the role of KAT14 in vivo.

RESULTS

KAT14 was upregulated in ectopic lesions from endometrioma patients and predominantly expressed in activated fibroblasts. In vitro studies showed that KAT14 overexpression significantly promoted a TGF-β-induced profibrotic response in endometrial stromal cells, while KAT14 silencing showed adverse effects that could be rescued by KAT14 re-enhancement. In vivo, Kat14 knockdown ameliorated fibrosis in the ectopic lesions of the endometriosis mouse model. Mechanistically, we showed that KAT14 directly interacted with serum response factor (SRF) to promote the expression of α-smooth muscle actin (α-SMA) by increasing histone H4 acetylation at promoter regions; this is necessary for TGF-β-induced ECM production and myofibroblast differentiation. In addition, the knockdown or pharmacological inhibition of SRF significantly attenuated KAT14-mediating profibrotic effects under TGF-β treatment. Notably, the KAT14/SRF complex was abundant in endometrioma samples and positively correlated with α-SMA expression, further supporting the key role of KAT14/SRF complex in the progression of endometrioma-associated fibrogenesis.

CONCLUSION

Our results shed light on KAT14 as a key effector of TGF-β-induced ECM production and myofibroblast differentiation in EcESCs by promoting histone H4 acetylation via co-operating with SRF, representing a potential therapeutic target for endometrioma-associated fibrosis.

Rectus Abdominis Endometriosis Following Cesarean Section: A Case Report

Endometriosis involves the growth of endometrial-like tissue outside the uterine cavity, with its manifestation in the rectus abdominis muscle being exceptionally rare and primarily observed in women with a history of abdominal surgeries. In this report, we present the case of a 42-year-old female with a medical history of two cesarean sections who presented with cyclical abdominal pain and a palpable mass in the right lower quadrant. An MRI scan of the pelvis revealed a lesion on the right lower quadrant of the abdominal wall, proximate to the previous Pfannenstiel incision. A percutaneous US-guided biopsy of the abdominal lesion was performed, and histopathology demonstrated the presence of endometrial glands and stroma, confirming the diagnosis of rectus abdominis endometriosis. She was submitted to a local wide excision with adequate margins of normal surrounding tissue and has remained free of recurrence for two years.

Molecular Mechanisms of Endometriosis Revealed Using Omics Data

Endometriosis is a gynecological disorder prevalent in women of reproductive age. The primary symptoms include dysmenorrhea, irregular menstruation, and infertility. However, the pathogenesis of endometriosis remains unclear. With the advent of high-throughput technologies, various omics experiments have been conducted to identify genes related to the pathophysiology of endometriosis. This review highlights the molecular mechanisms underlying endometriosis using omics. When genes identified in omics experiments were compared with endometriosis disease genes identified in independent studies, the number of overlapping genes was moderate. However, the characteristics of these genes were found to be equivalent when functional gene set enrichment analysis was performed using gene ontology and biological pathway information. These findings indicate that omics technology provides invaluable information regarding the pathophysiology of endometriosis. Moreover, the functional characteristics revealed using enrichment analysis provide important clues for discovering endometriosis disease genes in future research.

Elevated phosphorylation of estrogen receptor α at serine-118 in ovarian endometrioma

OBJECTIVE

To evaluate the phosphorylation of estrogen receptor α at serine-118 (phospho-ERα S118) in the endometrium, ovarian endometrioma, and deep infiltrating endometriosis (DIE).

DESIGN

Experimental study.

SETTING

University-affiliated hospital and academic research laboratory.

PATIENT(S)

Twenty-five patients underwent a hysterectomy, 18 patients underwent surgical removal of ovarian endometrioma, and 6 patients underwent DIE.

INTERVENTION(S)

Tissue samples were obtained from patients who underwent surgical procedures.

MAIN OUTCOME MEASURE(S)

Immunostaining for phospho-ERα S118, ERα, or phosphorylated p44/42 mitogen-activated protein kinase (phospho-p44/42 MAPK) was performed to evaluate the endometrium with or without endometriosis, ovarian endometrioma, and DIE. For in vitro analysis, endometrial epithelial cells (Ishikawa cells) were stimulated with estradiol (E2) or tumor necrosis factor alpha (TNFα), and the expression levels of phospho-ERα S118 and phospho-p44/42 MAPK were evaluated via Western blotting.

RESULT(S)

First, phospho-ERα S118 level was significantly higher in the glands and stroma of ovarian endometriosis samples than in those of endometrial and DIE samples. Second, colocalization of phospho-p44/42 MAPK and phospho-ERα S118 was observed in the glands of ovarian endometrioma. The proportions of cells strongly expressing phospho-p44/42 and phospho-ERα were 87% in phosphor-p44/42 MAPK-positive cells and 79% in phosphor-ERα-positive cells. Third, E2 stimulation significantly enhanced phospho-ERα S118 after 15 and 30 minutes in in vitro analysis using endometrial epithelial cells. Fourth, TNFα stimulation modestly but significantly enhanced phospho-ERα S118 after 15 and 30 minutes. Fifth, in Ishikawa cells, treatment with a p44/42 inhibitor (PD98059) significantly reduced phospho-ERα S118 by TNFα but not by E2.

CONCLUSION(S)

ERα-S118 phosphorylation was increased in ovarian endometriosis. Our findings may provide a new perspective for understanding the mechanism of increased ERα action in the pathophysiology of endometriosis.

Significance analysis of PAX8 expression in endometrial carcinoma

To analyze the expression and prognostic value of paired-box 8 (PAX8) expression in uterine corpus endometrial carcinoma (UCEC) by bioinformatics. The expression of PAX8 gene in UCEC was analyzed by R language and immunohistochemistry. The correlation between PAX8 expression and clinicopathological features was analyzed by R language. The prognostic factors was analyzed by univariate/multivariate regression. The survival curve of patients was analyzed by Kaplan-Meier Plotter (K-M Plotter). The diagnostic value of PAX8 in UCEC was analyzed by receiver operating characteristic curve, and the relationship between PAX8 expression and methylation was analyzed by Ualcan. The relationship between methylation and prognosis was analyzed by MethSurv database. The expression of PAX8 in cancer tissues was significantly higher than that in normal tissues. The expression of PAX8 was related to clinical stage, age, histological type, histologic grade, tumor invasion and disease-specific survival event. Univariate/multivariate regression analysis showed that clinical stage, tumor invasion, and PAX8 expression were the influence factors of overall survival (OS), while histologic grade and PAX8 expression were the influence factors of disease-specific survival, and patients with low expression had a longer OS. The area under the curve of receiver operating characteristic curve was 0.81 for PAX8 diagnosis of UCEC. PAX8 was hypomethylated in cancer tissue, and patients with hypermethylated PAX8 had a longer OS. The high expression of PAX8 induced by hypomethylation may play an important role in the occurrence and prognosis of UCEC.

The Importance of Stromal Endometriosis in Thoracic Endometriosis

Thoracic endometriosis (TE) is a rare type of endometriosis, where endometrial tissue is found in or around the lungs and is frequent among extra-pelvic endometriosis patients. Catamenial pneumothorax (CP) is the most common form of TE and is characterized by recurrent lung collapses around menstruation. In addition to histology, immunohistochemical evaluation of endometrial implants is used more frequently. In this review, we compared immunohistochemical (CPE) with histological (CPH) characterizations of TE/CP and reevaluated arguments in favor of the implantation theory of Sampson. A summary since the first immunohistochemical description in 1998 until 2019 is provided. The emphasis was on classification of endometrial implants into glands, stroma, and both together. The most remarkable finding is the very high percentage of stromal endometriosis of 52.7% (CPE) compared to 10.2% (CPH). Chest pain, dyspnea, right-sided preference, and diaphragmatic endometrial implants showed the highest percentages in both groups. No significant association was found between the recurrence rate and the various appearances of endometriosis. Sometimes in CPE (6.8%) and CPH (30.6%) no endometrial implants were identified underlining the importance of sensitive detection of endometriosis during and after surgery. We suggest that immunohistochemical evaluation should become mandatory and will improve diagnosis and classification of the disease.

Endometriosis of the Inguinal Canal Mimicking a Hydrocele of the Canal of Nuck

Isolated presentation of endometriosis of the inguinal canal is infrequent, and the clinical and imaging findings may be misleading in such patients. We describe an otherwise healthy female with isolated inguinal endometriosis presenting as a hydrocele of the canal of Nuck. Surgeons should consider such unusual presentations and obtain imaging and histological evaluations in doubtful instances. Complete excision was curative in our patient with no evidence of recurrence.

Extra-pelvic endometriosis: A review

Background

Extra‐pelvic endometriosis is a rare type of endometriosis, which occurs in a distant site from gynecological organs. The diagnosis of extra‐pelvic endometriosis can be extremely challenging and may result in a delay in diagnosis. The main objective of this review was to characterize abdominal wall endometriosis (AWE) and thoracic endometriosis (TE).

Methods

The authors performed a literature search to provide an overview of AWE and TE, which are the major types of extra‐pelvic endometriosis.

Main findings

Abdominal wall endometriosis includes scar endometriosis secondary to the surgical wound and spontaneous AWE, most of which occur in the umbilicus or groin. Surgical treatment appeared to be effective for AWE. Case reports indicated that the diagnosis and treatment of catamenial pneumothorax or endometriosis‐related pneumothorax (CP/ERP) are challenging, and a combination of surgery and postoperative hormonal therapy is essential. Further, catamenial hemoptysis (CH) can be adequately managed by hormonal treatment, unlike CP/ERP.

Conclusion

Evidence‐based approaches to diagnosis and treatment of extra‐pelvic endometriosis remain immature given the low prevalence and limited quality of research available in the literature. To gain a better understanding of extra‐pelvic endometriosis, it would be advisable to develop a registry involving a multidisciplinary collaboration with gynecologists, general surgeons, and thoracic surgeons.