WNT5A, ß­catenin and SUFU expression patterns, and the significance of microRNA deregulation in placentas with intrauterine growth restriction.

Placental insufficiency is a common cause of intrauterine growth restriction (IUGR). It affects ~10% of pregnancies and increases fetal and neonatal morbidity and mortality. Although Wnt and Hh pathways are crucial for embryonic development and placentation, their role in the pathology of IUGR is still not sufficiently explored. The present study analyzed the expression of positive regulators of the Wnt pathway, WNT5A and ß­catenin, and the expression of the Hh pathway negative regulator suppressor of fused (SUFU). Immunohistochemical and reverse transcription­quantitative PCR (RT­qPCR) assays were performed on 34 IUGR and 18 placental tissue samples from physiologic singleton­term pregnancies. Epigenetic mechanisms of SUFU gene regulation were also investigated by methylation­specific PCR analysis of its promoter and RT­qPCR analysis of miR­214­3p and miR­378a­5p expression. WNT5A protein expression was higher in endothelial cells of placental villi from IUGR compared with control tissues. That was also the case for ß­catenin protein expression in trophoblasts and endothelial cells and SUFU protein expression in trophoblasts from IUGR placentas. The SUFU gene promoter remained unmethylated in all tissue samples, while miR­214­3p and miR­378a­5p were downregulated in IUGR. The present results suggested altered Wnt and Hh signaling in IUGR. DNA methylation did not appear to be a mechanism of SUFU regulation in the pathogenesis of IUGR, but its expression could be regulated by miRNA targeting.

Endometrial Glucose Transporters in Health and Disease.

Pregnancy loss is a frequent occurrence during the peri-implantation period, when there is high glucose demand for embryonic development and endometrial decidualization. Glucose is among the most essential uterine fluid components required for those processes. Numerous studies associate abnormal glucose metabolism in the endometrium with a higher risk of adverse pregnancy outcomes. The endometrium is incapable of synthesizing glucose, which thus must be delivered into the uterine lumen by glucose transporters (GLUTs) and/or the sodium-dependent glucose transporter 1 (SGLT1). Among the 26 glucose transporters (14 GLUTs and 12 SGLTs) described, 10 (9 GLUTs and SGLT1) are expressed in rodents and 8 (7 GLUTs and SGLT1) in the human uterus. This review summarizes present knowledge on the most studied glucose transporters in the uterine endometrium (GLUT1, GLUT3, GLUT4, and GLUT8), whose data regarding function and regulation are still lacking. We present the recently discovered SGLT1 in the mouse and human endometrium, responsible for controlling glycogen accumulation essential for embryo implantation. Moreover, we describe the epigenetic regulation of endometrial GLUTs, as well as signaling pathways included in uterine GLUT's expression. Further investigation of the GLUTs function in different endometrial cells is of high importance, as numerous glucose transporters are associated with infertility, polycystic ovary syndrome, and gestational diabetes.

Dishevelled family proteins (DVL1-3) expression in intrauterine growth restriction (IUGR) placentas.

Dishevelled family proteins (DVL1, DVL2, and DVL3) are cytoplasmic proteins that are involved in canonical and non-canonical Wnt signaling pathway during embryonic development. The role of DVL proteins in the placental tissue remains mostly unknown. In the current study, we explored the role of Dishevelled proteins in naturally invasive tissue, trophoblast. Formalin-fixed paraffin-embedded samples of 15 term placentas from physiologic term pregnancies and 15 term placentas from pregnancies complicated with intrauterine growth restrictions (IUGR) were used for the study. Expression levels of mRNA for DVL1, DVL2, and DVL3 in placentas were analyzed by quantitative real-time PCR (qRTPCR). DVL1, DVL2, and DVL3 protein expression were semi-quantitatively analyzed using immunohistochemistry. The expression of DVL2 and DVL3 proteins was significantly higher in trophoblasts in placental villi from IUGR pregnancies compared with the control group of term placentas. In contrast, DVL3 protein expression was significantly higher in endothelial cells in placental villi from IUGR pregnancies compared with normal term placentas. The observed differences at protein levels between normal and IUGR placentas were not confirmed at the mRNA levels of DVL genes. Our data indicate the active involvement of DVL proteins in IUGR-related placentas. No significant changes were observed in DVL mRNA levels between the two groups of placentas. Further studies are required to explore the clinical relevance of these observations.

Dishevelled family proteins in serous ovarian carcinomas: a clinicopathologic and molecular study.

Dishevelled family proteins (DVL1, DVL2, and DVL3) are cytoplasmic mediators involved in canonical and non-canonical Wnt signaling that are important for embryonic development. Since Wnt signaling promotes cell proliferation and invasion, its increased activation is associated with cancer development as well. To get deeper insight into the behavior of Dishevelled proteins in cancer, we studied their expression in serous ovarian carcinomas [both low- (LGSC) and high-grade (HGSC)], and HGSC cell lines OVCAR5, OVCAR8, and OVSAHO. DVL protein expression in serous ovarian carcinomas tissues was analyzed using immunohistochemistry, while DVL protein and mRNA expressions in HGSC cell lines were analyzed using Western blot and quantitative real-time PCR. DVL1 protein expression was significantly higher in LGSC compared with normal ovarian tissue, while DVL3 was overexpressed in both LGSC and HGSC. DVL2 and DVL3 protein expression was higher in HGSC cell lines when compared with normal control cell line FNE1, while DVL1, DVL2, and DVL3 mRNA expression was significantly increased only in OVSAHO cell line. Survival analysis revealed no significant impact of DVL proteins on patients' outcome. Our data show an active involvement of Dishevelled family proteins in serous ovarian carcinomas. Further studies should confirm the clinical relevance of these observations.

Novel Epigenetic Biomarkers in Pregnancy-Related Disorders and Cancers.

As the majority of cancers and gestational diseases are prognostically stage- and grade-dependent, the ultimate goal of ongoing studies in precision medicine is to provide early and timely diagnosis of such disorders. These studies have enabled the development of various new diagnostic biomarkers, such as free circulating nucleic acids, and detection of their epigenetic changes. Recently, extracellular vesicles including exosomes, microvesicles, oncosomes, and apoptotic bodies have been recognized as powerful diagnostic tools. Extracellular vesicles carry specific proteins, lipids, DNAs, mRNAs, and miRNAs of the cells that produced them, thus reflecting the function of these cells. It is believed that exosomes, in particular, may be the optimal biomarkers of pathological pregnancies and cancers, especially those that are frequently diagnosed at an advanced stage, such as ovarian cancer. In the present review, we survey and critically appraise novel epigenetic biomarkers related to free circulating nucleic acids and extracellular vesicles, focusing especially on their status in trophoblasts (pregnancy) and neoplastic cells (cancers).