COX2 is induced in the ovarian epithelium during ovulatory wound repair and promotes cell survival†

TT-10 may attenuate ibuprofen-induced ovarian injury in mice by activating COX2-PGE2 and inhibiting Hippo pathway

Ibuprofen (IBU) is a non-steroidal anti-inflammatory drug that has been found in recent years to cause ovarian damage. The aim of this study is to explore the molecular mechanisms of IBU damage to the ovary and drugs to combat it. We established in vivo (IBU doses of 50, 100 and 200 mg/kg-day) and in vitro (IBU concentrations of 50, 100 and 200 μM in culture medium) models of ovarian damage in mice simulating clinical doses and found that IBU not only caused ovarian damage in mice in a dose-response relationship, but also decreased estradiol (E2) and prostaglandin E2 (PGE2) levels in serum/media with increasing IBU doses. In damaged ovaries, the cyclooxygenase 2 (COX2)-PGE2 pathway is inhibited, the Hippo pathway is activated, circPVT1 is decreased, and miR-149 is elevated. TT-10 is an activator of YES-associated protein (YAP)-transcriptional enhancer factor domain activity. Then, 100 μM IBU-induced ovarian damage model was selected for YAP activation (Hippo pathway inhibition) experiment, and TT-10 was found to interfere with IBU-induced ovarian damage and increase E2 level in the medium, and 10 μM of TT-10 had the best protective effect. TT-10 also inhibited the Hippo pathway, activated the COX2-PGE2 pathway, elevated circPVT1 expression, and decreased miR-149 expression in the ovary. It has been hypothesized that clinical doses of IBU damage mouse ovaries by inhibiting COX2-PGE2 and activating the Hippo pathway, whereas TT-10 protects the ovaries through the inverse regulation of these two pathways.

Comparison of Steroidogenic and Ovulation-Inducing Effects of Orthosteric and Allosteric Agonists of Luteinizing Hormone/Chorionic Gonadotropin Receptor in Immature Female Rats

Gonadotropins, including human chorionic gonadotropin (hCG), are used to induce ovulation, but they have a number of side effects, including ovarian hyperstimulation syndrome (OHSS). A possible alternative is allosteric luteinizing hormone (LH)/hCG receptor agonists, including the compound TP4/2 we developed, which remains active when administered orally. The aim was to study the effectiveness of TP4/2 (orally, 40 mg/kg) as an ovulation inducer in FSH-stimulated immature female rats, compared with hCG (s.c., 15 IU/rat). TP4/2 stimulated progesterone production and corpus luteum formation; time-dependently increased the ovarian expression of steroidogenic genes (Star, Cyp11a1, Cyp17a1) and genes involved in ovulation regulation (Adamts-1, Cox-2, Egr-1, Mt-1); and increased the content of metalloproteinase ADAMTS-1 in the ovaries. These effects were similar to those of hCG, although in some cases they were less pronounced. TP4/2, in contrast to hCG, maintained normal LH levels and increased the ovarian expression of the LH/hCG receptor gene, indicating preservation of ovarian sensitivity to LH, and did not cause a sustained increase in expression of vascular endothelial growth factor-A involved in OHSS. Thus, TP4/2 is an effective ovulation inducer that, unlike hCG, has a lower risk of OHSS and ovarian LH resistance due to its moderate stimulating effect on steroidogenesis.

TT-10 may elevate YAP and repair mouse uterine damage resulting from the inhibition effect of ibuprofen on COX2-PGE2 and YAP

Ibuprofen (IBU) is an emerging environmental contaminant that, in high doses, can damage reproductive organs in humans and other mammals. Recently, its effects on the uterus have been investigated. It is known that the COX2-PGE2 pathway and Yes-associated protein (YAP) are involved in female reproductive organ development and form a COX2-PGE2-EP2-Gas-β-catenin-YAP-COX2 positive feedback loop, in addition, TT-10, a pharmacological product, has been found to increase YAP. In this study, IBU was orally administrated to female mice for 7 d at doses of 0, 50, 100, and 200 mg/kg·bw/day (control, low, medium, and high doses, respectively). In addition, 0, 50, 100, and 200 μmol/L IBU was added in vitro to cultured uterine cells for 7 d at control, low, medium, and high doses, respectively; then, 0, 5, 10, and 20 μmol/L TT-10 were given to the in vitro uterine culture containing 100 μmol/L IBU to observe the effect of YAP activation. The results showed that medium and high doses of IBU inhibited the COX2-PGE2 pathway, decreasing YAP and increasing pYAP, leading to reduced circPVT1, elevated miR-149, and increased apoptosis, ultimately damaging the uterus. Conversely, 10 μmol/L TT-10 maximally enhanced YAP, which regulated COX2-PGE2 pathway activation, increased circPVT1, and decreased miR-149, and promoted cell proliferation, preventing uterine damage. This suggests that IBU may cause uterine damage by inhibiting the COX2-PGE2 pathway and YAP, and that appropriate doses of TT-10 may repair this damage by elevating YAP and stimulating COX2 via the feedback loop.

Predictors of residual disease after debulking surgery in advanced stage ovarian cancer

Objective

Optimal debulking with no macroscopic residual disease strongly predicts ovarian cancer survival. The ability to predict likelihood of optimal debulking, which may be partially dependent on tumor biology, could inform clinical decision-making regarding use of neoadjuvant chemotherapy. Thus, we developed a prediction model including epidemiological factors and tumor markers of residual disease after primary debulking surgery.

Methods

Univariate analyses examined associations of 11 pre-diagnosis epidemiologic factors (n=593) and 24 tumor markers (n=204) with debulking status among incident, high-stage, epithelial ovarian cancer cases from the Nurses' Health Studies and New England Case Control study. We used Bayesian model averaging (BMA) to develop prediction models of optimal debulking with 5x5-fold cross-validation and calculated the area under the curve (AUC).

Results

Current aspirin use was associated with lower odds of optimal debulking compared to never use (OR=0.52, 95%CI=0.31-0.86) and two tissue markers, ADRB2 (OR=2.21, 95%CI=1.23-4.41) and FAP (OR=1.91, 95%CI=1.24-3.05) were associated with increased odds of optimal debulking. The BMA selected aspirin, parity, and menopausal status as the epidemiologic/clinical predictors with the posterior effect probability ≥20%. While the prediction model with epidemiologic/clinical predictors had low performance (average AUC=0.49), the model adding tissue biomarkers showed improved, but weak, performance (average AUC=0.62).

Conclusions

Addition of ovarian tumor tissue markers to our multivariable prediction models based on epidemiologic/clinical data slightly improved the model performance, suggesting debulking status may be in part driven by tumor characteristics. Larger studies are warranted to identify those at high risk of poor surgical outcomes informing personalized treatment.

Lifetime ovulatory years and ovarian cancer gene expression profiles

BACKGROUND

Greater ovulatory years is associated with increased ovarian cancer risk. Although ovulation leads to an acute pro-inflammatory local environment, how long-term exposure to ovulation impacts ovarian carcinogenesis is not fully understood. Thus, we examined the association between gene expression profiles of ovarian tumors and lifetime ovulatory years to enhance understanding of associated biological pathways.

METHODS

RNA sequencing data was generated on 234 invasive ovarian cancer tumors that were high-grade serous, poorly differentiated, or high-grade endometrioid from the Nurses' Health Study (NHS), NHSII, and the New England Case Control Study. We used linear regression to identify differentially expressed genes by estimated ovulatory years, adjusted for birth decade and cohort, overall and stratified by menopausal status at diagnosis. We used false discovery rates (FDR) to account for multiple testing. Gene set enrichment analysis (GSEA) with Cancer Hallmarks, KEGG, and Reactome databases was used to identify biological pathways associated with ovulatory years.

RESULTS

No individual genes were significantly differentially expressed by ovulatory years (FDR > 0.19). However, GSEA identified several pathways that were significantly associated with ovulatory years, including downregulation of pathways related to inflammation and proliferation (FDR < 1.0 × 10-5). Greater ovulatory years were more strongly associated with downregulation of genes related to proliferation (e.g., E2F targets, FDR = 1.53 × 10-24; G2M checkpoints, FDR = 3.50 × 10-22) among premenopausal versus postmenopausal women at diagnosis. The association of greater ovulatory years with downregulation of genes involved in inflammatory response such as interferon gamma response pathways (FDR = 7.81 × 10-17) was stronger in postmenopausal women.

CONCLUSIONS

Our results provide novel insight into the biological pathways that link ovulatory years to ovarian carcinogenesis, which may lead to development of targeted prevention strategies for ovarian cancer.

Cellular Processes in Human Ovarian Follicles Are Regulated by Expression Profile of New Gene Markers—Clinical Approach

In the growing ovarian follicle, the maturing oocyte is accompanied by cumulus (CCs) and granulosa (GCs) cells. Currently, there remain many unanswered questions about the epithelial origin of these cells. Global and targeted gene transcript levels were assessed on 1, 7, 15, 30 days of culture for CCs and GCs. Detailed analysis of the genes belonging to epithelial cell-associated ontological groups allowed us to assess a total of 168 genes expressed in CCs (97 genes) and GCs (71 genes) during long-term in vitro culture. Expression changes of the analyzed genes allowed the identification of the group of genes: TGFBR3, PTGS2, PRKX, AHI1, and IL11, whose expression decreased the most and the group of ANXA3, DKK1, CCND1, STC1, CAV1, and SFRP4 genes, whose expression significantly increased. These genes’ expression indicates CCs and GCs epithelialization processes and their epithelial origin. Expression change analysis of genes involved in epithelization processes in GCs and CCs during their in vitro culture made it possible to describe the most significantly altered of the 11 genes. Detailed analysis of gene expression in these two cell populations at different time intervals confirms their ovarian surface epithelial origin. Furthermore, some gene expression profiles appear to have tumorigenic properties, suggesting that granulosa cells may play a role in cancerogenesis.

Common Analgesic Use for Menstrual Pain and Ovarian Cancer Risk

Menstrual pain has been associated with increased ovarian cancer risk, presumably through increased inflammation, which is known to play a critical role in ovarian carcinogenesis. Analgesic medications are frequently used to treat menstrual pain, some of which lower ovarian cancer risk. In this study, we examined the association between analgesic use for menstrual pain during the premenopausal period and ovarian cancer risk among women with history of menstrual pain. We used data from the New England Case-Control Study, including 1,187 epithelial ovarian cancer cases and 1,225 population-based controls enrolled between 1998 and 2008 with detailed information on analgesic use for their menstrual pain. We used unconditional logistic regression to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the association between analgesic use (i.e., aspirin, ibuprofen, acetaminophen) for menstrual pain and ovarian cancer risk. We further conducted a stratified analysis by intensity of menstrual pain (mild/moderate, severe). Among women with menstrual pain during their 20s and 30s, ever use of analgesics for menstrual pain was not significantly associated with ovarian cancer risk. However, among women with severe menstrual pain, ever use of aspirin or acetaminophen for menstrual pain was inversely associated with risk (OR, 0.41; 95% CI, 0.18-0.94 and OR, 0.43; 95% CI, 0.21-0.88 compared with never users, respectively). No significant association was observed between analgesic use and ovarian cancer risk among women with mild/moderate menstrual pain (P interaction ≤ 0.03). Our results suggest that use of aspirin or acetaminophen for severe menstrual pain may be associated with lower risk of ovarian cancer. PREVENTION RELEVANCE: This study investigates whether analgesic use specifically for menstrual pain during the premenopausal period influences ovarian cancer risk. Our results suggest use of aspirin or acetaminophen for severe menstrual pain may be associated with lower risk of ovarian cancer among women with severe menstrual pain.

Transcriptional heterogeneity of stemness phenotypes in the ovarian epithelium

The ovarian surface epithelium (OSE) is a monolayer of epithelial cells surrounding the ovary that ruptures during each ovulation to allow release of the oocyte. This wound is quickly repaired, but mechanisms promoting repair are poorly understood. The contribution of tissue-resident stem cells in the homeostasis of several epithelial tissues is widely accepted, but their involvement in OSE is unclear. We show that traits associated with stem cells can be increased following exposure to the cytokine TGFB1, overexpression of the transcription factor Snai1, or deletion of Brca1. We find that stemness is often linked to mesenchymal-associated gene expression and higher activation of ERK signalling, but is not consistently dependent on their activation. Expression profiles of these populations are extremely context specific, suggesting that stemness may not be associated with a single, distinct population, but rather is a heterogeneous cell state that may emerge from diverse environmental cues. These findings support that the OSE may not require distinct stem cells for long-term maintenance, and may instead achieve this through transient dedifferentiation into a stem-like state.

Using spheroids as a model, the authors report the molecular signatures of ovarian surface epithelial (OSE) cells exhibiting stemness phenotype under various conditions in vitro, and found that there is a large degree of heterogeneity in the transcriptional profiles of stem cells induced under different conditions. They suggest that maintenance of the OSE may not require a single stem cell population, but heterogeneous stem cells that can be induced transiently under diverse environmental cues.

Non-canonical WNT5a regulates Epithelial-to-Mesenchymal Transition in the mouse ovarian surface epithelium

The ovarian surface epithelium (OSE) is a monolayer that covers the ovarian surface and is involved in ovulation by rupturing and enabling release of a mature oocyte and by repairing the wound after ovulation. Epithelial-to-mesenchymal transition (EMT) is a mechanism that may promote wound healing after ovulation. While this process is poorly understood in the OSE, in other tissues wound repair is known to be under the control of the local microenvironment and different growth factors such as the WNT signaling pathway. Among WNT family members, WNT4 and WNT5a are expressed in the OSE and are critical for the ovulatory process. The objective of this study was to determine the potential roles of WNT4 and WNT5a in regulating the OSE layer. Using primary cultures of mouse OSE cells, we found WNT5a, but not WNT4, promotes EMT through a non-canonical Ca2+-dependent pathway, up-regulating the expression of Vimentin and CD44, enhancing cell migration, and inhibiting the CTNNB1 pathway and proliferation. We conclude that WNT5a is a stimulator of the EMT in OSE cells, and acts by suppressing canonical WNT signaling activity and inducing the non-canonical Ca2+ pathway.

Ovulation and ovarian wound healing are impaired with advanced reproductive age

Aging is associated with reduced tissue remodeling efficiency and increased fibrosis, characterized by excess collagen accumulation and altered matrix degradation. Ovulation, the process by which an egg is released from the ovary, is one of the most dynamic cycles of tissue wounding and repair. Because the ovary is one of the first organs to age, ovulation and ovarian wound healing is impaired with advanced reproductive age. To test this hypothesis, we induced superovulation in reproductively young and old mice and determined the numbers of eggs ovulated and corpora lutea (CLs), the progesterone producing glands formed post-ovulation. Reproductively old mice ovulated fewer eggs and had fewer CLs relative to young controls. Moreover, reproductively old mice exhibited a greater number of oocytes trapped within CLs and expanded cumulus oocyte complexes within unruptured antral follicles, indicative of failed ovulation. In addition, post-ovulatory tissue remodeling was compromised with age as evidenced by reduced CL vasculature, increased collagen, decreased hyaluronan, decreased cell proliferation and apoptosis, impaired wound healing capacity, and aberrant morphology of the ovarian surface epithelium (OSE). These findings demonstrate that ovulatory dysfunction is an additional mechanism underlying the age-related loss of fertility beyond the reduction of egg quantity and quality.