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Yerushalmi G.M.,IVF Unit and Reproduction Laboratory | Yerushalmi G.M.,Tel Aviv University | Markman S.,IVF Unit and Reproduction Laboratory | Markman S.,Tel Aviv University | And 11 more authors.
Science Translational Medicine | Year: 2016

Prostaglandins (PGs) play an important role in the ovulatory process. However, the role of the PG transporter (PGT) in this context remains unknown. We report that the expression of PGT, a transmembrane PG carrier protein, is markedly up-regulated in preovulatory human granulosa cells (GCs). Treatment with human chorionic gonadotropin (hCG), an ovulatory trigger, significantly increases the expression of PGT mRNA and protein in human GCs both in vivo and in vitro. The hCG-induced increase in the expression of PGT in cultured human GCs is mediated via protein kinase A and protein kinase C by way of the extracellular signal-regulated kinase pathway. PGT in cultured human GCs mediates the uptake of PGE2, thereby regulating its extracellular concentration. In vivo treatment of mice with PGT inhibitors effectively blocks ovulation and markedly attenuates the expression of key ovulatory genes. We hypothesize that the inhibition of PGT activity in GCs increases the extracellular concentration of PGE2, the ability of which to exert its ovulatory effect is compromised by desensitization of its cognate receptors. Together, these findings support the idea that PGT is an important mediator of ovulation and that its inhibitors may be viewed as potential candidates for nonhormonal contraception. These findings may also fill the gap in the understanding of PGT signaling, enhance the understanding of ovulatory disorders, and facilitate the treatment of infertility or subfertility in women by using nonsteroidal PG-based therapeutic approaches. Source

Bahar-Shany K.,Sheba Cancer Research Center | Brand H.,Sheba Cancer Research Center | Brand H.,Tel Aviv University | Sapoznik S.,Sheba Cancer Research Center | And 9 more authors.
Gynecologic Oncology | Year: 2014

Objectives Ovulation-related inflammation is suspected to have a causal role in ovarian carcinogenesis, but there are no human models to study the molecular pathways. Our aim is to develop such an ex-vivo model based on human fallopian tube (FT) epithelium exposed to human follicular fluid (FF). Methods FT epithelium was dissociated from normal surgical specimens. FF was obtained from donors undergoing in-vitro fertilization. The cells were cultured on collagen-coated Transwells and incubated with FF for various periods of time. The transcriptomic changes resulting from FF treatment were profiled using Affymetrix expression arrays. Specific characteristics of the FT pre-cancerous lesions were studied using immunohistochemistry, immunofluorescence, RT-PCR and XTT assay. Results We show that FF exposure causes up-regulation of inflammatory and DNA repair pathways. Double stranded DNA breaks are induced. There is a minor increase in cell proliferation. TP53, which is the hallmark of the precursor lesion in-vivo, is accumulated. Levels of expression and secretion of Interleukin-8 are significantly increased. Conclusions Our model addresses the main non-genetic risk factor for ovarian cancer, namely the impact of ovulation. This study demonstrates the biological implications of in-vitro exposure of human FT epithelial cells to FF. The model replicates elements characterizing the precursor lesions of ovarian cancer, and warrants further investigation of the linkage between repeated exposure to ovulation-related damage and accumulation of neoplastic changes. © 2013 Elsevier Inc. All rights reserved. Source

Sapoznik S.,Sheba Cancer Research Center | Bahar-Shany K.,Sheba Cancer Research Center | Brand H.,Sheba Cancer Research Center | Brand H.,Tel Aviv University | And 20 more authors.
Neoplasia (United States) | Year: 2016

In recent years, the notion that ovarian carcinoma results from ovulation-induced inflammation of the fallopian tube epithelial cells (FTECs) has gained evidence. However, the mechanistic pathway for this process has not been revealed yet. In the current study, we propose the mutator protein activation-induced cytidine deaminase (AID) as a link between ovulation-induced inflammation in FTECs and genotoxic damage leading to ovarian carcinogenesis. We show that AID, previously shown to be functional only in B lymphocytes, is expressed in FTECs under physiological conditions, and is induced in vitro upon ovulatory-like stimulation and in vivo in carcinoma-associated FTECs. We also report that AID activity results in epigenetic, genetic and genomic damage in FTECs. Overall, our data provides new insights into the etiology of ovarian carcinogenesis and may set the ground for innovative approaches aimed at prevention and early detection. © 2015 The Authors. Source

Kedem A.,IVF Unit and Reproduction Laboratory | Hourvitz A.,IVF Unit and Reproduction Laboratory | Yung Y.,IVF Unit and Reproduction Laboratory | Shalev L.,IVF Unit and Reproduction Laboratory | And 4 more authors.
Gynecological Endocrinology | Year: 2013

Purpose: To prospectively study the AMH expression and secretion pattern in mural granulosa cells (GCs) and follicular fluid (FF) from small follicles and medium follicles that were collected from normo-ovulatory (NO) and polycystic ovary syndrome (PCOS) patients undergoing in vitro maturation (IVM) treatments. Methods: FF AMH levels and mRNA expression of mural GCs were measured in small (≤10 mm) and medium size follicles (11-15 mm) obtained from IVM treatments and large size follicles (≥16 mm) obtained from in vitro fertilization treatments. Results: First, we show that AMH expression and protein level in the FF of NO patients were significantly higher in the small size follicles than in the medium and large size follicles (p < 0.003). We could not demonstrate these differences in PCOS patients. Second, we found significantly higher levels of AMH protein and mRNA in the large and medium (but not small) size follicles of PCOS patients compared to follicles from NO patients (p < 0.02). Finally, we observed a positive correlation between FF AMH of small and medium size follicles from NO patients and serum AMH (p < 0.03 and p < 0.0002, respectively). Conclusions: Our data demonstrate a pathological dysregulation of AMH expression and secretion in follicles from PCOS patients and emphasize the association between the physiological downregulation of AMH and follicular antral health. © 2013 Informa UK Ltd. Source

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