Temporal and spatial expression of glyceraldehyde 3-phosphate dehydrogenase (Gapdh) in the mouse placenta

Screening the optimal housekeeping genes (HKGs) of placenta tissues by RNA-sequence and qRT-PCR throughout gestation in goat (Capra Hircus)

Selection of stable housekeeping genes (HKGs) is very important for accurate calculation of relative expression levels of target genes by quantitative real-time polymerase chain reaction (qRT-PCR). At present, the appropriate HKGs have not been identified in placental tissues throughout the pregnancy of the goat. In our study, 20 HKGs were tentatively selected from RNA-seq data and previous reports. The cycle threshold (Ct) of HKGs was determined by qRT-PCR in trophoblast membrane and cotyledon villus collected from 38 Dazu Black goats on gestation days of 20, 25, 30, 45, 60, 90, 120, and 150 (birth). The expression stability of the HKGs was analyzed by geNorm, Normfinder, Bestkeeper and Delta Ct algorithms, and comprehensively evaluated by ReFinder and ComprFinder. In addition, the optimal HKGs were further verified by placenta-specific genes (SPP1, VEGFA and PAG6). The 16 candidate HKGs (except POP4, TBP, RNF10, UBC) showed a qualified Ct value, less than 28. Among them, YWHAZ, EIF3K and PPIB showed the most stable expression in placental tissues during early, mid-late pregnancy and postpartum, but the least stable expression was B2M at early and mid-late stage, and PPIB at postpartum. After comprehensive analysis, RPLP0, EIF3K and YWHAZ were found to be the most stable placental HKGs throughout pregnancy. The classical HKGs, ACTB, GAPDH and 18S RNA have unstable expressions and even ranked at the bottom of the list from comprehensive index, suggesting an inappropriate for target gene normalization. Taken together, our study confirmed that YWHAZ, EIF3K, HMBS and RPLP0 may be the optimal HKGs in goat placenta at different stage of pregnancy, which provided a valuable reference of HKGs on functional gene expression detection for further research on placenta development and growth in ruminants.

Effect of 2-deoxyglucose-mediated inhibition of glycolysis on migration and invasion of HTR-8/SVneo trophoblast cells

The proper invasion of trophoblasts is crucial for embryo implantation and placental development, which is helpful to establish a correct maternal-fetal relationship. Trophoblasts can produce a large amount of lactate through aerobic glycolysis during early pregnancy. Lactate creates a low pH microenvironment around the embryo to help uterine tissue decompose and promote the invasion of trophoblasts. The purpose of this study is to reveal the the potential mechanism of aerobic glycolysis regulating the invasiveness of trophoblasts by investigating the effect of 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor, on the biological function of HTR-8/SVneo trophoblast cells, the expressions of epithelial mesenchymal transformation (EMT) markers and invasion-related factors. 2-DG could inhibit the aerobic glycolysis of trophoblasts and decrease the activity of trophoblasts in a dose-dependent manner. Moreover, 2-DG inhibited the EMT of HTR-8/SVneo cells, down-regulated the expression of invasion-related factors matrix metalloproteinase 2/9 (MMP2/9) and up-regulated the expression of tissue inhibitor of matrix metalloproteinases 1/2 (TIMP1/2), thus inhibiting cell migration and invasion. This paper provides a foundation in the significance of aerobic glycolysis of trophoblasts in the process of invasion, and also provides ideas and insights for the promotion of embryo implantation.

Heat stress affects fetal brain and intestinal function associated with the alterations of placental barrier in late pregnant mouse

High ambient temperature-induced heat stress (HS) during pregnancy may affect the placental function and fetal development. Late gestation is a critical period of the developing fetal brain and intestine. The study aimed to investigate the effects of HS during late pregnancy on the function of placenta, fetal brain and intestine in a mouse model. We found that the number of stillborn fetal mice were increased due to maternal HS. Transcriptome analysis revealed that the expression of genes enriched in nutrients transport and metabolism of HS group were up-regulated in the placenta, but down-regulated in the fetal duodenum and jejunum. Interestingly, the concentration of triglyceride (TG) in the HS group was raised in the placenta, but reduced both in the fetal duodenum and jejunum compared with the thermal-neutral (TN) group. Additionally, maternal HS also reduced total cholesterol (TC) contents in the fetal duodenum. The mRNA expression and protein levels of placental fatty acid binding protein 2 and 4 (fabp2 and fabp4) were not affected by maternal HS, but the mRNA expression and protein levels of cluster of differentiation 36 (CD36) and diacylglycerol acyltransferase-2 (Dgat2) were decreased in the fetal intestine. Furthermore, maternal HS reduced the mRNA expression and protein levels of the placental 11beta-hydroxysteroid dehydrogenase type 2 (Hsd11b2) and 5-hydroxytryptamine receptor 1D (Htr1d). The concentrations of corticosterone and the expression of heat shock protein 90 beta family member 1 (hsp90b1), hypoxia up-regulated 1 (hyou1) and corticotropin releasing hormone receptor 1 (crhr1) enriched in response to glucocorticoids in the fetal brain were increased by maternal HS. Taken together, our findings demonstrated that maternal HS disrupted the placental glucocorticoid barrier and serotonin system associated with the raised corticosterone levels in the fetal brain, which might contribute to the decreased capacity of nutrients transport and metabolism in the fetal intestine.

Protein Phosphatase 2A Activation Via ApoER2 in Trophoblasts Drives Preeclampsia in a Mouse Model of the Antiphospholipid Syndrome

[Figure: see text].

Network analysis reveals important genes in human placenta

AIM

To determine which genes are important in placenta by network analysis.

METHODS

Placenta expressing genes were screened from RNA-Seq data. Protein-protein interaction data were downloaded from STRING (v11.0) database. Google PageRank (PR) algorithm was used to identify important placental genes from protein interaction network. Six placental disease-related datasets were downloaded from NCBI GEO database, and the differential expression of the 99 genes was identified.

RESULTS

We calculated PR for each placenta expressing gene and defined the top 99 genes with high PR as important genes. GAPDH has the highest PR. The 99 genes had different expression pattern in placental cell types. FN1 is up-regulated in 8 w EVT compared to 8 w CTB and 24 w EVT compared to 8 w EVT. HSPA4 is down-regulated in 8 w EVT compared to 8 w CTB and 24 w EVT compared to 8 w EVT. MIB2, TLR4, and UBB are consistently changed in preeclampsia (PE). UBB and ACTG1 were identified to be down-regulated in fetal growth restriction (FGR). SOD1 is down-regulated in preterm birth placenta.

CONCLUSION

Our findings confirmed that the importance of these genes in placenta-related diseases, and provide new candidates (MIB2, UBB, ACTG1, and SOD1) for placenta-related disease diagnosis and treatment.

Selection of reliable reference genes for analysis of gene expression in the rat placenta

The selection of suitable reference genes (RGs), especially the identification of the proper combination of RGs is the key to obtain reliable results of gene expression for quantitative real-time polymerase chain reaction (qRT-PCR). To date, there is no relevant study dealing with the stability of RGs in rat placenta. In this study, the geNorm, NormFinder, and BestKeeper software were used to analyze the expression stability of the candidate RGs in placenta under physiological and prenatal caffeine exposure (PCE) conditions. The expression of Tbp, Gapdh and Ywhaz in female and Polr2a, Gapdh and Ywhaz in male placenta were highly stable under physiological conditions, and there was no obvious gender difference. We further found that two RGs were sufficient for reliable normalization in female and male placenta and the combination of Ywhaz and Gapdh was the most suitable compound RGs under physiological conditions. Under PCE conditions, Ywhaz, Gapdh and Polr2a were the most stable genes in both female and male placenta. Among them, Ywhaz and Gapdh were chosen as the best paring. Finally, selected RGs were employed for normalization of the expression of a clear target gene and the results of standardization supported our choice. In conclusion, our study confirmed that Ywhaz/Gapdh combination was the most suitable RGs in rat placenta under physiological and PCE pathological conditions and provided a theoretical and experimental basis for physiological and pathological research of the rat placenta.

Drug transport across the human placenta: review of placenta-on-a-chip and previous approaches

In the past few decades, the placenta became a very controversial topic that has had many researchers and pharmacists discussing the significance of the effects of pharmaceutical drug intake and how it is a possible leading cause towards birth defects. The creation of an in vitro microengineered model of the placenta can be used to replicate the interactions between the mother and fetus, specifically pharmaceutical drug intake reactions. As the field of nanotechnology significantly continues growing, nanotechnology will become more apparent in the study of medicine and other scientific disciplines, specifically microengineering applications. This review is based on past and current research that compares the feasibility and testing of the placenta-on-a-chip microengineered model to the previous and underdeveloped in vivo and ex vivo approaches. The testing of the practicality and effectiveness of the in vitro, in vivo and ex vivo models requires the experimentation of prominent pharmaceutical drugs that most mothers consume during pregnancy. In this case, these drugs need to be studied and tested more often. However, there are challenges associated with the in vitro, in vivo and ex vivo processes when developing a practical placental model, which are discussed in further detail.