Developmental Changes in Extracellular Matrix Messenger RNAs in the Mouse Placenta During the Second Half of Pregnancy: Possible Factors Involved in the Regulation of Placental Extracellular Matrix Expression1

Aspirin Inhibits Fibronectin Expression and Reverses Fibronectin-Mediated Cell Invasiveness by Activating Akt Signaling in Preeclampsia

Preeclampsia is a severe gestational hypertensive disorder that may lead to maternal multiple organ dysfunction and adverse fetal outcomes. Aspirin provides a protective effect by reducing the risk of preeclampsia; however, its mechanism of action is unclear. Fibronectin (FN) is a key factor in cell motility and is associated with preeclampsia. Here, we demonstrated that cellular FN expression was elevated in the placenta of preeclamptic patients. The functional roles of plasma and cellular FN in trophoblasts were investigated by treating HTR-8/SVneo cells with exogenous recombinant human FN protein (rhFN) and siRNA, respectively. Trophoblast migration and invasion were inhibited by rhFN and facilitated by FN knockdown. Moreover, rhFN activated ERK and Akt signaling in trophoblasts, and FN-suppressed cell motility was rescued by ERK and/or Akt inhibitors. In this study, aspirin suppressed trophoblast cellular FN expression and reversed FN-mediated cell functions, including cell migration, invasion, and ERK/Akt signal changes. Taken together, the results of this study revealed the effects of FN on trophoblast motility and signaling; aspirin inhibits FN expression and reverses FN-mediated trophoblast biology. These results provide a drug mechanism for disease prevention and a target for preeclampsia intervention.

Follistatin Is a Novel Chemoattractant for Migration and Invasion of Placental Trophoblasts of Mice

Follistatin (FST) as a gonadal protein is central to the establishment and maintenance of pregnancy. Trophoblasts' migration and invasion into the endometrium are critical events in placental development. This study aimed to elucidate the role of FST in the migration and invasion of placental trophoblasts of mice. We found that FST increased the vitality and proliferation of primary cultured trophoblasts of embryonic day 8.5 (E8.5) mice and promoted wound healing of trophoblasts. Moreover, FST significantly induced migration of trophoblasts in a microfluidic device and increased the number of invasive trophoblasts by Matrigel-coated transwell invasion assay. Being treated with FST, the adhesion of trophoblasts was inhibited, but intracellular calcium flux of trophoblasts was increased. Western blotting results showed that FST had no significant effects on the level of p-Smad3 or the ratio of p-Smad3/Smad3 in trophoblasts. Interestingly, FST elevated the level of p-JNK; the ratio of p-JNK/JNK; and expression of migration-related proteins N-cadherin, vimentin, ezrin and MMP2 in trophoblasts. Additionally, the migration of trophoblasts and expression of N-cadherin, vimentin, and MMP2 in trophoblasts induced by FST were attenuated by JNK inhibitor AS601245. These findings suggest that the elevated FST in pregnancy may act as a chemokine to induce trophoblast migration and invasion through the enhanced JNK signaling to maintain trophoblast function and promote placental development.

Expression of cadherins and some connective tissue components in cow uterus and placenta during pregnancy

The implantation and placental development processes are regulated with cell adhesion molecules and remodeling of the maternal endometrium's extracellular matrices (ECM) and fetal chorion. This study aimed to investigate the distribution and localization of some classical cadherins (E-, N-, and P-cadherins) and extracellular matrix components collagen type 5α1, fibronectin, and laminin in the cow placentomes during pregnancy using immunohistochemical and Western blotting analyses. The study results confirmed the expression of E- and P-cadherins, collagen type Vα1 (COLVα1), fibronectin, and laminin in the cow placentomes, but not N-cadherin. Throughout the pregnancy, E- and P- cadherins, COLVα1, and laminin were localized in the luminal and glandular epithelium of the inter-caruncular endometrium, caruncular epithelium, and the uninucleate (UNCs) and binucleate trophoblast giant cells (BNCs/TGCs). E- cadherin immunoreactivity in the first pregnancy period was strong in the UNCs while moderate in the BNCs/TGCs. However, it was weak in both trophoblast in the second and third pregnancy periods. In the fetal trophoblasts, P- cadherin and laminin immunostainings were more intense in the BNCs/TGCs than UNCs. The fetal and maternal stromal cells were also positive for P- cadherin, COLVα1, fibronectin, and laminin. The immunostaining intensity of COLVα1 and fibronectin in the stromal extracellular matrix of the placentomes decreased as the pregnancy progressed. The endothelia of fetal and maternal vessels were positive for all proteins. The presence and distinct localization of cadherins and ECM proteins in the cow placentome components support the role of these molecules in regulating placental cell growth, migration, and matrix production during pregnancy.

Myostatin: a multifunctional role in human female reproduction and fertility - a short review

Myostatin (MSTN) is member of the transforming growth factor β (TGF-β) superfamily and was originally identified in the musculoskeletal system as a negative regulator of skeletal muscle growth. The functional roles of MSTN outside of the musculoskeletal system have aroused researchers' interest in recent years, with an increasing number of studies being conducted in this area. Notably, the expression of MSTN and its potential activities in various reproductive organs, including the ovary, placenta, and uterus, have recently been examined. Numerous studies published in the last few years demonstrate that MSTN plays a critical role in human reproduction and fertility, including the regulation of follicular development, ovarian steroidogenesis, granule-cell proliferation, and oocyte maturation regulation. Furthermore, findings from clinical samples suggest that MSTN may play a key role in the pathogenesis of several reproductive disorders such as uterine myoma, preeclampsia (PE), ovary hyperstimulation syndrome (OHSS), and polycystic ovarian syndrome (PCOS). There is no comprehensive review regarding to MSTN related to the female reproductive system in the literature. This review serves as a summary of the genes in reproductive medicine and their potential influence. We summarized MSTN expression in different compartments of the female reproductive system. Subsequently, we discuss the role of MSTN in both physiological and several pathological conditions related to the female fertility and reproduction-related diseases.

Integrins, anchors and signal transducers of hematopoietic stem cells during development and in adulthood

Hematopoietic stem cells (HSCs), the apex of the hierarchically organized blood cell production system, are generated in the yolk sac, aorta-gonad-mesonephros region and placenta of the developing embryo. To maintain life-long hematopoiesis, HSCs emigrate from their site of origin and seed in distinct microenvironments, called niches, of fetal liver and bone marrow where they receive supportive signals for self-renewal, expansion and production of hematopoietic progenitor cells (HPCs), which in turn orchestrate the production of the hematopoietic effector cells. The interactions of hematopoietic stem and progenitor cells (HSPCs) with niche components are to a large part mediated by the integrin superfamily of adhesion molecules. Here, we summarize the current knowledge regarding the functional properties of integrins and their activators, Talin-1 and Kindlin-3, for HSPC generation, function and fate decisions during development and in adulthood. In addition, we discuss integrin-mediated mechanosensing for HSC-niche interactions, ex vivo protocols aimed at expanding HSCs for therapeutic use, and recent approaches targeting the integrin-mediated adhesion in leukemia-inducing HSCs in their protecting, malignant niches.

Placental Tissues as Biomaterials in Regenerative Medicine

Placental tissues encompass all the tissues which support fetal development, including the placenta, placental membrane, umbilical cord, and amniotic fluid. Since the 1990s there has been renewed interest in the use of these tissues as a raw material for regenerative medicine applications. Placental tissues have been extensively studied for their potential contribution to tissue repair applications. Studies have attributed their efficacy in augmenting the healing process to the extracellular matrix scaffolds rich in collagens, glycosaminoglycans, and proteoglycans, as well as the presence of cytokines within the tissues that have been shown to stimulate re-epithelialization, promote angiogenesis, and aid in the reduction of inflammation and scarring. The compositions and properties of all birth tissues give them the potential to be valuable biomaterials for the development of new regenerative therapies. Herein, the development and compositions of each of these tissues are reviewed, with focus on the structural and signaling components that are relevant to medical applications. This review also explores current configurations and recent innovations in the use of placental tissues as biomaterials in regenerative medicine.

Melatonin Administration Prevents Placental and Fetal Changes Induced by Gestational Diabetes

Gestational diabetes mellitus (GDM) promotes changes in the placenta and fetuses, due to oxidative stress. Antioxidants can reduce oxidative stress in the placenta. We tested the hypothesis that melatonin (Mel) can prevent these effects in the placenta and fetuses, analyzing their histology, histochemistry, morphometry, and immunohistochemistry. Thirty albino rats were used, divided into groups: CG-pregnant non-diabetic rats; GD-pregnant diabetic rats; GD + Mel-pregnant diabetic rats treated with melatonin. Diabetes was induced by streptozotocin at a dosage of 50 mg/kg i.p. Melatonin was administered in daily injections of 0.8 mg/kg i.p. Melatonin prevented the placental weight and fetal weight and length from increasing, in addition to histomoformetric, histochemical, and immunohistochemical changes in the placentas, compared to the placentas of diabetic females (GD). Thus, we conclude that melatonin has a great potential to prevent placental changes due to GDM.

Effect of swimming exercise, insulin-associated or not, on inflammatory cytokines, apoptosis, and collagen in diabetic rat placentas

Physical exercise is an important therapeutic agent for women with diabetes during gestation. However, its histophysiological consequences for the placenta remain unclear. In this study, we evaluated the expression of VEGF-A, IL1ß, TNFα, and type I collagen in the placentas of diabetic rats subjected to a swimming program. Thirty rats were divided into the following groups: CG, pregnant nondiabetic rats; CEG, nondiabetic pregnant rats subjected to swimming; DG, pregnant diabetic rats; DEG, pregnant diabetic rats subjected to swimming; DIG, pregnant diabetic rats treated with insulin; DIEG, pregnant diabetic rats treated with insulin and subjected to swimming. Diabetes was induced using streptozotocin [50 mg/kg intraperitoneally (i.p.)], and insulin was administered at a dose of 5 U/day i.p. (2 U at 10 am and 3 U at 7 pm) in the DIG group; in the DIEG group, insulin was administered at a dose of only 2 U/day at 7 pm. The rats were sacrificed on the 20th day of gestation. There was an increase in the expression of IL-1β, TNF-α, VEGF-A, and type I collagen and a higher apoptotic index in the placentas of the DG and DEG groups, but there was a reduction in glycemia in the latter group. In the DIG and DIEG groups, the levels remained similar to those of the control; however, in these groups the reduction was more significant for all analyzed parameters. Therefore, in rats induced to diabetes during pregnancy, swimming, although reducing glycemic levels, did not prevent immunohistochemical changes in the placenta, suggesting the need for a multidisciplinary protocol associated with traditional pharmacological treatment.

Screening Candidate Genes Regulating Placental Development from Trophoblast Transcriptome at Early Pregnancy in Dazu Black Goats (Capra hircus)

Simple Summary

The trophoblast is an original placental tissue whose normal proliferation, differentiation, migration, adhesion, and angiopoiesis are essential for placenta formation and fetal survival during early pregnancy. However, the key genes and molecular mechanisms involved in placenta development in goats are unknown. Herein, the morphology and histological structures of trophoblast tissues from day 20 to 30 of pregnancy were determined. RNA-sequencing was used to screen potential functional genes in common highly expressed and differentially expressed genes. RAP1 signaling pathway was used as the contact center and coordinated with other pathways to regulate placenta development. This study could provide insights into the molecular mechanisms underlying ruminant placentation.

Abstract

This study explored the trophoblast transcriptome to understand potential functional genes involved in early placental development in goats and their enriched signaling pathways. Trophoblast samples were collected from nine Dazu Black goats on days 20, 25, and 30 of pregnancy (D20, D25, and D30). As the pregnancy progressed, the morphology and histological structures showed significant growth, adhesion, and angiogenesis. A total of 23,253 commonly expressed genes (CEGs) and 4439 differently expressed genes (DEGs) were detected by RNA sequencing. The common highly expressed genes (ChEGs) (the top 100 CEGs) with the highest FPKM percentage (29.9%) of all CEGs were annotated to the ribosome pathway and maintain pregnancy. DEGs were abundant in D30 vs. D20 (3715 DEGs). Besides, the DEGs were associated with the inhibition of oxidative phosphorylation and activation of PI3K-Akt, focal adhesion, ECM–receptor interaction, Rap1, and CAM signaling pathways. The RAP1 may be a central pathway since it coordinates with others to regulate the cell proliferation, invasion, migration, and fusion of trophoblasts. qRT-PCR and Western blot analysis confirmed the transcriptional expression in IGF1, VEGFC, RAPGEF3, PIK3CA, AKT3, ITGB3, ITGA11, SPP1, NOS1, and ATP6V0B genes and protein levels in VEGF, RAPGEF3, and Akt. This is the first study of transcriptome profiling in goat placenta and provides diverse genetic resources for further research on placenta development.

"Biological Adhesion" is a Significantly Regulated Molecular Process during Long-Term Primary In Vitro Culture of Oviductal Epithelial Cells (Oecs): A Transcriptomic and Proteomic Study

Oviductal epithelial cells (OECs) actively produce stimulating and protecting factors, favoring survival and viability of gametes and early embryos. The oviduct participates in the initial reproductive events, which strongly depends on adhesion. The analysis of differential gene expression in OECs, during long-term in vitro culture, enables recognition of new molecular markers regulating several processes, including "biological adhesion". Porcine oviducts were stained with hematoxylin and eosin, as well as with antibodies against epithelial markers. Then, OECs were long-term in vitro cultured and after 24 h, 7, 15, and 30 days of culture were subjected to transcriptomic and proteomic assays. Microarrays were employed to evaluate gene expression, with Matrix-assisted laser desorption/ionization-time of light (MALDI-TOF) mass spectrometry applied to determine the proteome. The results revealed proper morphology of the oviducts and typical epithelial structure of OECs during the culture. From the set of differentially expressed genes (DEGs), we have selected the 130 that encoded proteins detected by MALDI-TOF MS analysis. From this gene pool, 18 significantly enriched gene ontology biological processes (GO BP) terms were extracted. Among them we focused on genes belonging to "biological adhesion" GO BP. It is suggested that increased expression of studied genes can be attributed to the process of intensive secretion of substances that exhibit favorable influence on oviductal environment, which prime gametes adhesion and viability, fertilization, and early embryo journey.

Comparative Analysis of the Transcriptome and Proteome during Mouse Placental Development

The condition of the placenta is a determinant of the short- and long-term health of the mother and the fetus. However, critical processes occurring in early placental development, such as trophoblast invasion and establishment of placental metabolism, remain poorly understood. To gain a better understanding of the genes involved in regulating these processes, we utilized a multiomics approach, incorporating transcriptome, proteome, and phosphoproteome data generated from mouse placental tissue collected at two critical developmental time points. We found that incorporating information from both the transcriptome and proteome identifies genes associated with time point-specific biological processes, unlike using the proteome alone. We further inferred genes upregulated on the basis of the proteome data but not the transcriptome data at each time point, leading us to identify 27 genes that we predict to have a role in trophoblast migration or placental metabolism. Finally, using the phosphoproteome data set, we discovered novel phosphosites that may play crucial roles in the regulation of placental transcription factors. By generating the largest proteome and phosphoproteome data sets in the developing placenta, and integrating transcriptome analysis, we uncovered novel aspects of placental gene regulation.

Deciphering transcriptional regulation in human embryonic stem cells specified towards a trophoblast fate

Differentiated human embryonic stem cells (hESC) continue to provide a model for studying early trophoblast cells (TB), but many questions have been raised regarding their true identity. Therefore, we carried out a global and unbiased analysis on previously published transcriptomic profiles for hESC differentiated to TB by means of bone morphogenetic protein-4 and inhibitors of activin A and fibroblast growth factor-2 signaling (BAP treatment). Our results confirm that BAP treated hESC (ESCd) lack a mesoderm signature and are a subtype of placental cells unlike those present at term. ESCd display a high level of expression of genes implicated in migration and invasion compared to commonly used, immortalized TB cell lines and primary cells from term placenta. Co-expression network analysis also identified gene modules involved in cell migration and adhesion, processes that are likely critical during the beginning stages of placentation. Finally, protein-protein interaction analysis predicted several additional genes that may play important roles in early stages of placental development. Together, our analyses provide novel insights into the transcriptional programs that are active in ESCd.

Deficits in receptor-mediated endocytosis and recycling in cells from mice with Gpr107 locus disruption

GPR107 is a type III integral membrane protein that was initially predicted to be a member of the family of G-protein-coupled receptors. This report shows that deletion of Gpr107 leads to an embryonic lethal phenotype that is characterized by a reduction in cubilin transcript abundance and a decrease in the representation of multiple genes implicated in the cubilin-megalin endocytic receptor complex (megalin is also known as LRP2). Gpr107-null fibroblast cells exhibit reduced transferrin internalization, decreased uptake of low-density lipoprotein (LDL) receptor-related protein-1 (LRP1) cargo and resistance to toxins. Colocalization studies and proteomic analyses suggest that GPR107 associates with clathrin and the retromer protein VPS35 and that GPR107 might be responsible for the return of receptors to the plasma membrane from endocytic compartments. The highly selective deficits observed in Gpr107-null cells indicate that GPR107 interacts directly or indirectly with a limited subset of surface receptors.

Aberrant placenta gene expression pattern in bovine pregnancies established after transfer of cloned or in vitro produced embryos

In the present study, we used the global transcriptome profile approach to identify dysregulated genes, molecular pathways, and molecular functional alterations in bovine placentas derived from somatic cell nuclear transfer (SCNT) and in vitro embryo production (IVP) pregnancies compared with their artificial insemination (AI) counterparts at day 50 of gestation. For this, day 7 blastocysts derived from AI, IVP, or SCNT were transferred to oestrus-synchronized cows. The pregnant animals were slaughtered at day 50 of gestation, and the placentas were then recovered and used for transcriptome analysis using Affymetrix GeneChip bovine genome array. Results showed the SCNT placenta to be different from its AI counterpart in the expression of 1,196 transcripts. These genes were found to be associated with alterations in key biological processes and molecular pathways in SCNT placenta, and the dysregulation of 9% (n = 110) of these genes was due to transcriptional reprogramming error. IVP placenta also displayed alterations in the expression of 72 genes, of which 58 were common to SCNT placenta. Gene enrichment analysis revealed that the expression of genes involved in organ development, blood vessel development, extracellular matrix organization, and the immune system was affected in both SCNT and IVP placentas. However, 96% of the affected genes in SCNT were not significantly altered in IVP groups. Thus, the higher transcriptome dysregulation in SCNT placenta followed by IVP would reflect the degree of placental abnormality in SCNT and IVP pregnancies at day 50 of the gestation, which may have a profound effect on subsequent fetal development and health of the offspring.

The expression and potential functions of placental myostatin

Myostatin (growth differentiation factor-8; GDF-8) is a potent negative regulator of muscle development affecting both proliferation and differentiation. Myostatin has been reported to enhance the release of cytokines, including TNF-α (a pro-inflammatory cytokine involved in implantation). In the human placenta, myostatin production is negatively correlated with gestational age and has been implicated in the control of glucose uptake. Preliminary data indicate its expression is primarily localized to cytotrophoblast and syncytiotrophoblast. The role of myostatin in the placenta, however, remains to be fully elucidated. We speculate that myostatin is key regulator that contributes to placentation and the regulation of placental function throughout pregnancy.

Impaired IL-17 signaling pathway contributes to the increased collagen expression in scleroderma fibroblasts

Among IL-17 families, IL-17A and IL-17F share amino acid sequence similarity and bind to IL-17R type A. IL-17 signaling is implicated in the pathogenesis of various autoimmune diseases, but its role in the regulatory mechanism of extracellular matrix expression and its contribution to the phenotype of systemic sclerosis (SSc) both remain to be elucidated. This study revealed that IL-17A expression was significantly increased in the involved skin and sera of SSc patients, whereas the IL-17F levels did not increase. In contrast, the expression of IL-17R type A in SSc fibroblasts significantly decreased in comparison with that in normal fibroblasts, due to the intrinsic TGF-β1 activation in these cell types. Moreover, IL-17A, not IL-17F, reduced the protein expression of α1(I) collagen and connective tissue growth factor. miR-129-5p, one of the downregulated microRNAs in SSc fibroblasts, increased due to IL-17A and mediated the α1(I) collagen reduction. These results suggest that IL-17A signaling, not IL-17F, has an antifibrogenic effect via the upregulation of miR-129-5p and the downregulation of connective tissue growth factor and α1(I) collagen. IL-17A signaling is suppressed due to the downregulation of the receptor by the intrinsic activation of TGF-β1 in SSc fibroblasts, which may amplify the increased collagen accumulation and fibrosis characteristic of SSc. Increased IL-17A levels in the sera and involved skin of SSc may be due to negative feedback. Clarifying the novel regulatory mechanisms of fibrosis by the cytokine network consisting of TGF-β and IL-17A may lead to a new therapeutic approach for this disease.

High glucose suppresses epidermal growth factor receptor/phosphatidylinositol 3-kinase/Akt signaling pathway and attenuates corneal epithelial wound healing

OBJECTIVE

Patients with diabetes are at an increased risk for developing corneal complications and delayed wound healing. This study investigated the effects of high glucose on epidermal growth factor receptor (EGFR) signaling and on epithelial wound healing in the cornea.

RESEARCH DESIGN AND METHODS

Effects of high glucose on wound healing and on EGFR signaling were investigated in cultured porcine corneas, human corneal epithelial cells, and human corneas using Western blotting and immunofluorescence. Effects of high glucose on reactive oxygen species (ROS) and glutathione levels and on EGFR pathways were assessed in porcine and primary human corneal epithelial cells, respectively. The effects of EGFR ligands and antioxidants on high glucose-delayed epithelial wound healing were assessed in cultured porcine corneas.

RESULTS

High glucose impaired ex vivo epithelial wound healing and disturbed cell responses and EGFR signaling to wounding. High glucose suppressed Akt phosphorylation in an ROS-sensitive manner and decreased intracellular glutathione in cultured porcine corneas. Exposure to high glucose for 24 h resulted in an increase in ROS-positive cells in primary human corneal epithelial cells. Whereas heparin-binding EGF-like growth factor and antioxidant N-acetylcysteine had beneficial effects on epithelial wound closure, their combination significantly accelerated high glucose-delayed wound healing to a level similar to that seen in control subjects. Finally, Akt signaling pathway was perturbed in the epithelia of human diabetic corneas, but not in the corneas of nondiabetic, age-matched donors.

CONCLUSIONS

High glucose, likely through ROS, impairs the EGFR-phosphatidylinositol 3-kinase/Akt pathway, resulting in delayed corneal epithelial wound healing. Antioxidants in combination with EGFR ligands may be promising potential therapeutics for diabetic keratopathy.