Expression and regulation of Foxa2 in the rat uterus during early pregnancy

Exome-Sequencing Identifies Novel Genes Associated with Recurrent Pregnancy Loss in a Chinese Cohort

Recurrent pregnancy loss (RPL) is a common reproductive problem affecting around 5% of couples worldwide. At present, about half of RPL cases remained unexplained. Previous studies have suggested an important role for genetic determinants in the etiology of RPL. Here, we performed whole-exome sequencing (WES) analysis on 100 unrelated Han Chinese women with a history of two or more spontaneous abortions. We identified 6736 rare deleterious nonsynonymous variants across all patients. To focus on possible candidate genes, we generated a list of 95 highly relevant genes that were functionally associated with miscarriage according to human and mouse model studies, and found 35 heterozygous variants of 28 RPL-associated genes in 32 patients. Four genes (FOXA2, FGA, F13A1, and KHDC3L) were identified as being strong candidates. The FOXA2 nonsense variant was for the first time reported here in women with RPL. FOXA2 knockdown in HEK-293T cells significantly diminished the mRNA and protein expression levels of LIF, a pivotal factor for maternal receptivity and blastocyst implantation. The other genes, with 29 variants, were involved in angiogenesis, the immune response and inflammation, cell growth and proliferation, which are functionally important processes for implantation and pregnancy. Our study identified several potential causal genetic variants in women with RPL by WES, highlighting the important role of genes controlling coagulation, confirming the pathogenic role of KHDC3L and identifying FOXA2 as a newly identified causal gene in women with RPL.

Gene expression of bovine endometrial epithelial cells cultured in matrigel

Glandular epithelial cells (GE) in the endometrium are thought to support the elongation and survival of ruminant embryos by secreting histotrophs. In the present study, the gene expression of bovine endometrial epithelial cells cultured in matrigel was analyzed and examined whether it could be an in vitro model of GE. Bovine endometrial epithelial cells (BEE) and stromal cells (BES) were isolated from the slaughterhouse uteri and cultured in DMEM/F12 + 10% FBS. BEE showed the gland-like structure morphological changes when cultured in 15% matrigel but could not be identified in higher concentrations of the matrigel (30% or 60%). The expression of typical genes expressed in GE, SERPINA14 and GRP, was substantially high in matrigel-cultured BEE than in monolayer (P  <  0.05). P4 and INFα have no significant effect on the SERPINA14 expression of BEE cultured in matrigel without co-culture with BES. On the other hand, when BEE were co-cultured with BES in matrigel culture, the expression of FGF13 was increased by the P4 treatment (P  <  0.05). Furthermore, SERPINA14 and TXN expressions were increased by P4 + IFNα treatment (P  <  0.05). These results demonstrate the appropriate conditions for BEE to form glandular structures in matrigel and the effect of co-culture with BES. The present study highlighted the possible use of matrigel for the culture of BEE to investigate the expression of cell-specific glandular epithelial genes as well as P4 and type-I IFN as factors controlling endometrial function during the implantation period.

Advanced oxidation protein products change biological behaviors of rat endometrial epithelial cells by activating ERK/P38 signaling pathways

Advanced oxidation protein products (AOPPs) are a family of oxidized protein compounds and could induce oxidative stress and inflammatory lesion in various cells. The accumulation of AOPPs was associated with female reproductive diseases such as polycystic ovary syndrome (PCOS), leiomyoma and endometriosis. However, the relationship between AOPPs and endometrial cells is unclear. To explore the effects of accumulated AOPPs on endometrial cells, we treated normal rat endometrial epithelial cells (rEECs) and endometriosis model rats with AOPPs. Primary rEECs were collected from 8-week-old female Wistar rats. Increasing the amount of AOPPs in the media of rEECs enhanced rEEC proliferation and migration, and inhibited apoptosis. Moreover, AOPPs triggered the production of reactive oxygen species and nitrite along with activated ERK and P38 signal and this, in turn, led to an upregulation of proliferation and migration. With the treatment of antioxidants or the inhibitors of ERK and P38, the above effects of AOPPs on rEECs were attenuated. Additionally, in an endometriosis rat model, a similar phenomenon was observed in that the growth of endometriotic implants were promoted by AOPPs and EECs were significantly increased. This study indicated that the accumulation of AOPPs could promote rEEC proliferation and migration through ERK and P38 signal both in vivo and in vitroThis article has an associated First Person interview with the first author of the paper.

Development of an in vitro model to study uterine functions and early implantation using rat uterine explants

This study was conducted to develop an in vitro model using rat uterine explants to explore complex uterine functions. Rat uterine explants (1-2 mm) were isolated, cultured and further characterized. Steroid hormone treatment of cultured explants showed that both Muc1 and Pr were significantly up-regulated (P < 0.05) by E2. Areg was significantly up-regulated (P < 0.05) by P4 and Igfbp1 was significantly up-regulated (P < 0.05) by the combination of E2 and P4, although, in rat, Igfbp1 is E2-dependent. In vitro decidualization of cultured explants was induced and two potential markers of decidualization, Prl8a2 and Bmp2, were examined. Real-time quantitative PCR data revealed that both Prl8a2 and Bmp2 were significantly up-regulated (P < 0.05) in MPA- and db-cAMP-treated explants compared to the control group of explants. Then, an individual hatched blastocyst and cultured explant was placed in a 96-well (round-bottom U-shaped) plate. Co-culture results showed that stable attachments were observed after 48 h, where embryos were stably attached to the explants and could not be dislodged after mild shaking and/or pipetting. The rates of attachment of embryos to the explants were increased significantly in the P4-treated group (63.6%) compared to the control group (35.5%), after steroid hormone treatment. The rates of attachment were reduced significantly in the E2-treated group (0.0%), where no stable attachments were observed. Despite the necessity of comprehensive investigation, our results suggest that the cultured rat uterine explants can be a useful in vitro model to study uterine functions and early implantation.

The FOXA2 transcription factor is frequently somatically mutated in uterine carcinosarcomas and carcinomas

BACKGROUND

Uterine carcinosarcomas (UCSs) are a rare but clinically aggressive form of cancer. They are biphasic tumors consisting of both epithelial and sarcomatous components. The majority of uterine carcinosarcomas are clonal, with the carcinomatous cells undergoing metaplasia to give rise to the sarcomatous component. The objective of the current study was to identify novel somatically mutated genes in UCSs.

METHODS

We whole exome sequenced paired tumor and nontumor DNAs from 14 UCSs and orthogonally validated 464 somatic variants using Sanger sequencing. Fifteen genes that were somatically mutated in at least 2 tumor exomes were Sanger sequenced in another 39 primary UCSs.

RESULTS

Overall, among 53 UCSs in the current study, the most frequently mutated of these 15 genes were tumor protein p53 (TP53) (75.5%), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (34.0%), protein phosphatase 2, regulatory subunit A, alpha (PPP2R1A) (18.9%), F-box and WD repeat domain containing 7 (FBXW7) (18.9%), chromodomain helicase DNA binding protein 4 (CHD4) (17.0%), and forkhead box A2 (FOXA2) (15.1%). FOXA2 has not previously been implicated in UCSs and was predominated by frameshift and nonsense mutations. One UCS with a FOXA2 frameshift mutation expressed truncated FOXA2 protein by immunoblotting. Sequencing of FOXA2 in 160 primary endometrial carcinomas revealed somatic mutations in 5.7% of serous, 22.7% of clear cell, 9% of endometrioid, and 11.1% of mixed endometrial carcinomas, the majority of which were frameshift mutations.

CONCLUSIONS

Collectively, the findings of the current study provide compelling genetic evidence that FOXA2 is a pathogenic driver gene in the etiology of primary uterine cancers, including UCSs. Cancer 2018;124:65-73. © 2017 American Cancer Society.

Growth factor induced proliferation, migration, and lumen formation of rat endometrial epithelial cells in vitro

Endometrial modulation is essential for the preservation of normal uterine physiology, and this modulation is driven by a number of growth factors. The present study investigated the mitogenic, motogenic, and morphogenic effects of epidermal growth factor (EGF) and hepatocyte growth factor (HGF) on rat endometrial epithelial (REE) cells. The REE cells were isolated and cultured and then characterized based on their morphology and their expression of epithelial cell markers. The MTT assay revealed that EGF and HGF induce proliferation of REE cells. Consistent with increased proliferation, we found that the cell cycle regulatory factor Cyclin D1 was also upregulated upon EGF and HGF addition. REE cell migration was prompted by EGF, as observed with the Oris Cell Migration Assay. The morphogenic impact of growth factors on REE cells was studied in a three-dimensional BD Matrigel cell culture system, wherein these growth factors also increased the frequency of lumen formation. In summary, we show that EGF and HGF have a stimulatory effect on REE cells, promoting proliferation, cell migration, and lumen formation. Our findings provide important insights that further the understanding of endometrial regeneration and its regulation.

Neonatal Progesterone Programs Adult Uterine Responses to Progesterone and Susceptibility to Uterine Dysfunction

In this report, we investigated the consequences of neonatal progesterone exposure on adult rat uterine function. Female pups were subcutaneously injected with vehicle or progesterone from postnatal days 3 to 9. Early progesterone exposure affected endometrial gland biogenesis, puberty, decidualization, and fertility. Because decidualization and pregnancy success are directly linked to progesterone action on the uterus, we investigated the responsiveness of the adult uterus to progesterone. We first identified progesterone-dependent uterine gene expression using RNA sequencing and quantitative RT-PCR in Holtzman Sprague-Dawley rats and progesterone-resistant Brown Norway rats. The impact of neonatal progesterone treatment on adult uterine progesterone responsiveness was next investigated using quantitative RT-PCR. Progesterone resistance affected the spectrum and total number of progesterone-responsive genes and the magnitude of uterine responses for a subset of progesterone targets. Several progesterone-responsive genes in adult uterus exhibited significantly dampened responses in neonatally progesterone-treated females compared with those of vehicle-treated controls, whereas other progesterone-responsive transcripts did not differ between female rats exposed to vehicle or progesterone as neonates. The organizational actions of progesterone on the uterus were dependent on signaling through the progesterone receptor but not estrogen receptor 1. To summarize, neonatal progesterone exposure leads to disturbances in endometrial gland biogenesis, progesterone resistance, and uterine dysfunction. Neonatal progesterone effectively programs adult uterine responsiveness to progesterone.