Upregulation of VEGF by small activating RNA and its implications in preeclampsia

Therapeutic effect of E-Lip-siRNA-sFlt1 on pre-eclampsia: targeted gene silencing and improved pregnancy outcomes

Aim: To evaluate a liposome complex conjugated with anti-epidermal growth factor receptor (EGFR) antibodies for the treatment of pre-eclampsia (PE). Methods: In in vitro experiments, the transfection rate, silencing effect and cytotoxicity were determined. In the in vivo PE model, the siRNA distribution, mean arterial pressure, 24-h urine protein concentration, serum sFlt1 concentration, number of viable fetuses and placental weight were measured. Results: The nanomedicine effectively reduced the expression of sFIt1 and had a strong ability to target placental tissues. It could significantly reduce the symptoms of pre-eclampsia and improve pregnancy outcomes in PE model rats. Conclusion: The constructed nanomedicine can improve pregnancy outcomes in a rat model of pre-eclampsia and provides a new strategy for the treatment of pre-eclampsia.

Expression of insulin-like growth factor binding protein-3 in HELLP syndrome

OBJECTIVE

To investigate the expression of insulin-like growth factor binding protein-3(IGFBP-3) in HELLP syndrome and its possible role in the pathogenesis of this disease.

METHODS

1) 87 subjects were enrolled, including 29 patients with HELLP syndrome, 29 patients with pre-eclampsia (PE), and 29 healthy gravidae as control. The levels of IGFBP-3, IGF-1, TGF-β1, and VEGF in maternal and umbilical blood of them were detected using ELISA. Correlation analysis was used to observe the correlation between IGFBP-3 and IGF-1/TGF-β1/VEGF in maternal and umbilical blood, as well as that between maternal serum IGFBP-3 and clinical diagnostic indicators of HELLP syndrome. 2) Human hepatic sinusoid endothelial cells (HLSEC) and human umbilical vein endothelial cells (HUVEC) were cultured with different concentrations of IGFBP-3. After 72 h of culture, cell apoptosis and the normal living cells rate were detected and compared.

RESULTS

1) In both maternal and umbilical blood of HELLP group, levels of IGFBP-3 and TGF-β1 were higher than control and PE group, IGF-1was lower than control group, VEGF was lower than control and PE group. IGFBP-3 in maternal blood was correlated with IGF-1/TGF-β1/ VEGF, while IGFBP-3 in umbilical blood was linked to IGF-1/TGF-β1. In maternal blood, there was a negative correlation between PLT and IGFBP-3, and a positive correlation between ALT/AST/LDH and IGFBP-3. 2) After cultured with IGFBP-3, the total apoptosis rate of either HLSEC or HUVEC was considerably elevated, while the normal living rate was decreased.

CONCLUSION

The expression of IGFBP-3 is elevated in HELLP syndrome, which may subsequently promote cell apoptosis by affecting the expression and function of IGF-1, VEGF, and TGFβ1 in the IGF/PI3K/Akt, TGF-β1/Smad3, and VEGF/eNOS/NO pathways. IGFBP-3 aggravates inflammatory reactions of the vascular endothelium and liver under hypoxia, affects the normal function of cells, and plays a role in the pathogenesis of diseases.

MALAT1 modulates trophoblast phenotype via miR-101-3p/VEGFA axis

Preeclampsia is a potentially life-threatening condition that can arise due to poor placentation and consequent abnormal uterine spiral artery remodeling. Abnormal placentation, in turn, is associated with aberrant trophoblast cell proliferation and apoptosis. Here, we investigated the lncRNA MALAT1 in trophoblast proliferation during early-onset preeclampsia (ePE). MALAT1 levels were examined in placental tissue samples from ePE patients and control patients. The effects and underlying mechanism of MALAT1 on proliferation, migration, invasion and apoptosis were investigated in the first-trimester extravillous trophoblast HTR-8/SVneo cells and the human choriocarcinoma JAR cells. MALAT1 levels were decreased in the placental tissue samples of ePE patients compared with those of control patients, and the levels of MALAT1 were positively correlated with the neonate birth-weight. Knockdown of MALAT1 attenuated the cell viability, proliferation, migration, invasion and the cell cycle progression of trophoblasts, but promoted the apoptosis of trophoblasts. The MALAT1 knockdown promoted miR-101-3p upregulation and VEGFA downregulation. Inhibitor of miR-101-3p increased vascular endothelial growth factor A (VEGFA) expression, and miR-101-3p mimic inhibited VEGFA expression. Luciferase assays showed that miR-101-3p could bind to both MALAT1 and VEGFA. The MALAT1 knockdown-induced induction in the cell vitality and proliferation were attenuated by miR-101-3p inhibitor. We conclude that endogenous MALAT1 promotes proliferation, migration and invasion of trophoblasts by inhibiting the miR-101-3p expression and the subsequent VEGFA downregulation. The reduced MALAT1 level in placental tissue may be involved in the pathogenesis of the ePE.

Eco-friendly deacetylated chitosan base siRNA biological-nanopesticide loading cyromazine for efficiently controlling Spodoptera frugiperda

Spodoptera frugiperda is a serious threat to various crops, such as corn and rice, and results in severe economic losses. Herein, a chitin synthase sfCHS highly expressed in the epidermis of S. frugiperda was screened, and when interfered by an sfCHS-siRNA nanocomplex, most individuals could not ecdysis (mortality rate 53.3 %) or pupate (abnormal pupation 80.6 %). Based on the results of structure-based virtual screening, cyromazine (CYR, binding free energy -57.285 kcal/mol) could inhibit ecdysis (LC₅₀, 19.599 μg/g). CYR-CS/siRNA nanoparticles encapsulating CYR and SfCHS-siRNA with chitosan (CS) were successfully prepared, as confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and 74.9 mg/g CYR was characterized in the core of CYR-CS/siRNA by high-performance liquid chromatography and Fourier transform infrared spectroscopy. Small amounts of prepared CYR-CS/siRNA containing only 1.5 μg/g CYR could better inhibit chitin synthesis in the cuticle and peritrophic membrane (mortality rate 84.4 %). Therefore, chitosan/siRNA nanoparticle-loaded pesticides were useful for pesticide reduction and comprehensive control of S. frugiperda.

FtMt reduces oxidative stress-induced trophoblast cell dysfunction via the HIF-1α/VEGF signaling pathway

BACKGROUND

Preeclampsia (PE) is a complication of pregnancy that causes long-term adverse outcomes for the mother and fetus and may even lead to death. Oxidative stress caused by the imbalance of oxidants and antioxidants in the placenta has been considered as one of the key mechanisms of preeclampsia (together with inflammation, etc.), in which the placental mitochondria play an important role. The expression of hypoxia-inducible factor-1 (HIF-1α) and vascular endothelial growth factor (VEGF) is known to be increased in patients with PE. Mitochondrial ferritin (FtMt) is known to protect the mitochondria from oxidative stress, although its specific role in PE remains unclear.

METHODS

We used qRT-PCR and western blotting to detect the expression levels of FtMt, HIF-1α, and VEGF in placental tissues from patients with PE. Human chorionic trophoblast cells were also administered with hypoxia treatment, followed by the detection of cell proliferation, invasion and angiogenic capacity by CCK8, Transwell, and endothelial cell angiogenesis assays; we also detected the expression of HIF-1α and VEGF in these cells. Finally, overexpression or inhibitory FtMt lentiviral vectors, along with negative control vectors, were constructed and transfected into hypoxia-treated human chorionic trophoblast cells; this was followed by analyses of cell function.

RESULTS

The expression levels of FtMt, HIF-1α and VEGF in the PE group were higher than those in the control group (P < 0.05). Following hypoxia, there was an increase in the expression levels of HIF-1α and VEGF protein in trophoblast cells. There was also an increase in invasion ability and vascular formation ability along with a reduction in cell proliferation ability. These effects were reversed by transfecting cells with the knockout FtMt lentivirus vector. The differences were statistically significant.

CONCLUSION

Analyses showed that FtMt plays a key role in the vascular regulation of PE trophoblast cells after hypoxia possibly acting via the HIF-1α/VEGF signaling pathway. These results provide us an enhanced understanding of the pathogenesis of PE and suggest that the HIF-1α/VEGF signaling pathway represents a new target for the treatment of PE.

Placental Mitochondrial Function and Dysfunction in Preeclampsia

The placenta is a vital organ of pregnancy, regulating adaptation to pregnancy, gestational parent/fetal exchange, and ultimately, fetal development and growth. Not surprisingly, in cases of placental dysfunction-where aspects of placental development or function become compromised-adverse pregnancy outcomes can result. One common placenta-mediated disorder of pregnancy is preeclampsia (PE), a hypertensive disorder of pregnancy with a highly heterogeneous clinical presentation. The wide array of clinical characteristics observed in pregnant individuals and neonates of a PE pregnancy are likely the result of distinct forms of placental pathology underlying the PE diagnosis, explaining why no one common intervention has proven effective in the prevention or treatment of PE. The historical paradigm of placental pathology in PE highlights an important role for utero-placental malperfusion, placental hypoxia and oxidative stress, and a critical role for placental mitochondrial dysfunction in the pathogenesis and progression of the disease. In the current review, the evidence of placental mitochondrial dysfunction in the context of PE will be summarized, highlighting how altered mitochondrial function may be a common feature across distinct PE subtypes. Further, advances in this field of study and therapeutic targeting of mitochondria as a promising intervention for PE will be discussed.

Progesterone Enhances the Invasion of Trophoblast Cells by Activating PI3K/AKT Signaling Pathway to Prevent Preeclampsia

We aimed to explore whether the effect of progesterone on preeclampsia via the PI3K/AKT signaling pathway. First, we studied the role of progesterone in preeclampsia patients and HTR-8/Svneo cells by adding progesterone. Then PI3K inhibitor LY294002 was added. The effects of progesterone on preeclampsia were also studied in animals by constructing a preeclampsia rat model. CCK-8 and Transwell assay were applied to measure cell viability and invasion ability. ELISA was performed to measure progesterone, MMP-2, MMP-9, pro-inflammatory factors TNF-α, IL-1β, and anti-inflammatory factors IL-4, IL-10, and IL-13 levels. HE staining was used to detect the pathological changes in uterine spiral artery. Western blot was performed to detect Cyclin D1, PCNA, MMP-2, MMP-9, inflammatory factors TNF-α, IL-1β, IL-4, IL-10, IL-13, and PI3K/AKT signaling pathway related proteins AKT, p-AKT, PI3K, and p-PI3K expressions. Progesterone could reduce blood pressure and urine protein in pregnant women with preeclampsia. TNF-α and IL-1β levels were decreased, but IL-4, IL-10, IL-13, cyclin D1, and PCNA levels were increased in pregnant women with preeclampsia after using progesterone. After the use of progesterone, the symptoms of the PE model group were improved. Among them, the lumen of the placental uterine spiral artery was enlarged, and the fibrinoid necrosis of the uterine wall and acute atherosclerotic lesions were relieved. In addition, progesterone promoted HTR-8/Svneo cells proliferation and invasion. However, high expression of MMP-2, MMP-9, p-AKT, and p-PI3K in Normal and preeclampsia groups caused by progesterone was weakened after adding LY294002, indicating that progesterone could activate PI3K/AKT signaling pathway to regulate HTR-8/Svneo cells. Progesterone decreased urine protein and blood pressure of preeclampsia rats in a concentration-dependent manner. Moreover, progesterone activated the PI3K/AKT signaling pathway and inhibited the inflammatory response in preeclampsia rats.

Preparation of a miR-155-activating nucleic acid nanoflower to study the molecular mechanism of miR-155 in inflammation

At present, the molecular mechanisms underlying inflammation remain unclear. In recent years, research on inflammation has focused on stimulating cell inflammation by using exogenous pro-inflammatory substances such as lipopolysaccharide (LPS) or inflammatory factors. To investigate the molecular mechanism of inflammation from a new perspective, we designed a nucleic acid nanoflowers (NFs) complex to directly activate inflammatory genes to study the inflammatory response without the need for external microbial factors to trigger an inflammatory response. An RNAa-type target gene-activated NFs was designed. Human umbilical vein endothelial cells (HUVECs) were transfected with NFs carrying small activating RNA (saRNAs) to directly co-activate microRNA (miR)-155 and SHIP1 genes. After RNA activation (RNAa)-type NFs were transferred into HUVECs, the expression of miR-155 and pro-inflammatory and cancer-related factors increased, anti-inflammatory factors were reduced, cell proliferation increased, and cell migration was promoted. IL-1β protein levels were decreased and SHIP1 expression was downregulated. When miR-155 and its target SHIP1 were both activated, the expression of both was unaltered, maintaining cell homeostasis. This points towards miR-155 overexpression can trigger inflammation, and that miR-155 and its target genes act as a molecular switch role in the development of inflammation.

Perfluoroctanoic acid (PFOA) enhances NOTCH-signaling in an angiogenesis model of placental trophoblast cells

Exposure to perfluoroalkyl substances (PFAS) was found to be associated with several pathological endpoints, including high cholesterol levels, specific defective functions of the immune system and reduced birth weight. While environmental PFAS have been recognized as threats for public health, surprisingly little is known about the underlying mechanisms of toxicity. We hypothesized that some of the observed vascular and developmental effects of environmental PFAS may share a common molecular pathway. At elevated levels of exposure to PFAS, a reduction in mean birth weight of newborns has been observed in combination with a high incidence rate of preeclampsia. As both, preeclampsia and reduced birth weight are consequences of an inadequate placental vascularization, we hypothesized that the adaptation of placental vasculature may get compromised by PFAS. We analyzed pseudo-vascular network formation and protein expression in the HTR8/SVneo cell line, an embryonic trophoblast cell type that is able to form vessel-like vascular networks in 3D-matrices, similar to endothelial cells. PFOA (perfluoroctanoic acid), but not PFOS (perfuoroctanesulfonic acid), induced morphological changes in the vascular 3D-network structure, without indications of compromised cellular viability. Incubation with PFOA reduced cellular sprouting and elongated isolated stalks in pseudo-vascular networks, while a γ-secretase inhibitor BMS-906024 induced directional opposite effects. We found a PFOA-induced increase in NOTCH intracellular domain (NICD) abundance in HTR8/SVneo, indicating that PFOA enhances NOTCH-signaling in this cell type. Enhancement of NOTCH-pathway by PFOA may be a key to understand the mode of action of PFAS, as this pathway is critically involved in many confirmed physiological/toxicological symptoms associated with PFAS exposure.

miR-150-5p mediates extravillous trophoblast cell migration and angiogenesis functions by regulating VEGF and MMP9

INTRODUCTION

miR-150-5p is involved in placenta function. Matrix metalloproteinases (MMPs) play important roles in migration and invasion of cells, while VEGF is the major contributing factor in angiogenesis, and they are related to miR-150-5p. However, the mechanism by which miR-150-5p regulates placental functions is not known. Thus, we investigated the influence of miR-150-5p on extravillous trophoblast function and the underlying epigenetic mechanism.

METHODS

Real-time PCR were used to detect the miR-150-5p in the placenta of patients with preeclampsia and normal pregnant women. HTR-8/SVneo and JEG-3 cells were transfected with miR-150-5p inhibitor. Furthermore, we used CoCl₂ to establish the hypoxia cell model. qRT-PCR and Western blot analysis were performed to detect VEGF and MMP9 expression levels in the transfected cells. Cell Counting Kit-8 assay was conducted to evaluate the proliferation ability. Wound-healing and transwell assays were used to detect the migration and invasion capacities. Tube formation assay was performed to evaluate the angiogenesis ability.

RESULTS

miR-150-5p was up-regulated in the placenta of patients with preeclampsia. Inhibition of miR-150-5p significantly enhanced migration, invasion, and angiogenesis ability of both JEG-3 and HTR-8/SVneo cells. Similar results were seen in the hypoxic HTR-8/SVneo cell model. Moreover, mRNA and protein expression levels of VEGF and MMP9 were upregulated by the inhibition of miR-150-5p.

DISCUSSION

miR-150-5p impacts placental cellular abilities, including migration, invasion, and angiogenesis of extravillous trophoblast cells. More importantly, miR-150-5p regulates VEGF and MMP9 expression. The results suggest that miR-150-5p may have an impact on placenta functions.

Different Polymorphisms of Vascular Endothelial Growth Factor Gene in Patients with Pre-Eclampsia among The Iranian Women Population

Background

Pre-eclampsia (PE) is a pregnancy complication and one of the leading causes of maternal and neonatal morbidity and mortality in the world. PE is characterized by high blood pressure and signs of damage to the other organs, most often the liver and kidneys. Given the importance of mutation in the vascular endothelial growth factor (VEGF) gene and its correlation with the incidence of PE, the relationship of VEGF encoding gene polymorphisms rs922583280, rs3025040 and rs10434 with the incidence of PE in the population of Iranian women was studied, in this research.

Materials and Methods

In this case-control study, 100 pregnant women with PE diagnosis and 50 healthy pregnant women were evaluated using Sanger sequencing method to determine genotypes rs922583280, rs3025040 and rs10434.

Results

There was no significant difference in the allele frequency of rs922583280 and rs3025040 polymorphisms between case and control groups (P>0.05), while frequency of the recessive allele (G) for rs10434 polymorphism was significantly higher in the case group compared to the control group (P=0.014, case=24%, control=12%). Frequency of the allele A in the control group was higher than the patient group (case=76%, control=88%). Frequency of AG genotype in the patient group was also higher than the control group. In addition, frequency of AA genotype in the control group was higher than the patient group (case=57%, control=78).

Conclusion

The results of this study demonstrated a significant difference between patient and control groups for the VEGF coding gene polymorphism rs10434 and it can affect the incidence of PE among Iranian women.

Long non-coding RNA HOX transcript antisense RNA (HOTAIR) suppresses the angiogenesis of human placentation by inhibiting vascular endothelial growth factor A expression

HOX transcript antisense RNA (HOTAIR) is a long non-coding RNA located within the Homeobox C (HOXC) gene cluster on chromosome 12. Previous studies have revealed that HOTAIR is overexpressed in many types of cancers and is associated with metastasis and poor survival rates; however, few reports have mentioned the relationship between HOTAIR and angiogenesis of the human placenta. The aim of the present study was to investigate the correlation between HOTAIR and vascular endothelial growth factor (VEGF) A in the human placenta. HOTAIR levels decreased significantly in human placenta with increasing gestational age, and were negatively correlated with VEGFA levels. Invitro assays revealed that HOTAIR overexpression suppressed the proliferation, migration, invasion and tube formation of human umbilical vein endothelial cells (HUVECs); however, inhibition of HOTAIR had the opposite effects. Furthermore, VEGFA overexpression reversed the inhibitory effect of HOTAIR on the proliferation, migration, invasion and tube formation of HUVECs. In addition, overexpression of HOTAIR significantly inhibited VEGFA expression. Notably, a luciferase reporter assay found that HOTAIR inhibited VEGFA transcription by directly targeting the VEGFA promoter. Together, these results suggest that HOTAIR plays an important role in suppressing angiogenesis of the human placenta by inhibiting the expression of VEGFA; thus, HOTAIR may represent a potential therapeutic target for patients with human placental vascularisation abnormalities.

Placental mitochondria and reactive oxygen species in the physiology and pathophysiology of pregnancy

Mitochondria are central to cell function. The placenta forms the interface between maternal and fetal systems, and placental mitochondria have critical roles in maintaining pregnancy. The placenta is unusual in having two adjacent cell layers (cytotrophoblasts and the syncytiotrophoblast) with vastly different mitochondria that have distinct functions in health and disease. Mitochondria both produce the majority of reactive oxygen species (ROS), and are sensitive to ROS. ROS are important in allowing cells to sense their environment through mitochondrial-centred signalling, and this signalling also helps cells/tissues adapt to changing environments. However, excessive ROS are damaging, and increased ROS levels are associated with pregnancy complications, including the important disorders preeclampsia and gestational diabetes mellitus. Here we review the function of placental mitochondria in healthy pregnancy, and also in pregnancy complications. Placental mitochondria are critical to cell function, and mitochondrial damage is a feature of pregnancy complications. However, the responsiveness of mitochondria to ROS signalling may be central to placental adaptations that mitigate damage, and placental mitochondria are an attractive target for the development of therapeutics to improve pregnancy outcomes.

Activating the Chromatin by Noncoding RNAs

SIGNIFICANCE

The extent and breadth of transcription have recently been uncovered and this has revealed an extensive array of noncoding RNAs (ncRNAs). The biological role and significance of these ncRNAs have been realized and to date it appears that ncRNAs may have many important regulatory functions. ncRNAs are multifaceted and they induce a complexity of different types of transcriptional and posttranscriptional regulation, including gene activation. Recent Advances: Association of ncRNAs with gene activation is an important finding. Not only enhancer RNA (eRNA) but other types of ncRNAs, including small RNA (sRNA), long-noncoding RNA (lncRNA), microRNA (miRNA), and PIWI-associated RNA (piRNA), have also been implicated in gene activation. Interestingly, they often coincide with histone modifications that favor an open chromatin. In addition, these ncRNAs can recruit key factors important for transcription, including RNA polymerase II. They may directly bind the genomic DNA or act as scaffolds; alternatively, they may loop the chromatin to enhance transcription.

CRITICAL ISSUES

Although the role of small activating (sa)RNAs has been considerably studied, the roles of miRNAs and piRNAs in gene activation still need to be substantiated and issues of specificity require further studies.

FUTURE DIRECTIONS

The ncRNA field is coming out of its infancy and we are gaining a global picture of the importance of ncRNAs. However, detailed mechanisms of action of the different ncRNAs are still to be determined. This may reveal novel ways of transcriptional regulation, which will facilitate our ability to utilize these regulatory pathways for research and therapeutic purposes. Antioxid. Redox Signal. 29, 813-831.

Effects of forkhead box protein M1 on trophoblast invasion and its role in preeclampsia development

The present study aimed to investigate the expression of the forkhead box protein M1 (FOXM1) in the placenta of patients with preeclampsia, and its effect on trophoblasts. A total of 28 patients with preeclampsia and 30 patients without preeclampsia (controls) who underwent cesarean section and were admitted to the Affiliated Hospital of Qingdao University between June 2013 and September 2016 were enrolled in the present study. The expression of FOXM1 in placental tissues was examined by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. HTR8/SVneo cells were used to measure the in vitro expression of the vascular endothelial growth factor (VEGF). The results demonstrated that FOXM1 expression was downregulated in the placental tissues of patient with preeclampsia (P<0.05). Following the silencing of FOXM1 expression, the proliferation of HTR8/SVneo cells was suppressed. The results of flow cytometry demonstrated that proportion of HTR8/SVneo cells in the G0/G1 phase and the proportion of apoptotic cells increased. The expression of the apoptosis regulator BCL-2, as well as the expression of VEGF mRNA and protein expression were also downregulated following FOXM1 silencing. FOXM1 may therefore promote the development of preeclampsia via the VEGF signaling pathway.

saRNAdb: Resource of Small Activating RNAs for Up-regulating the Gene Expression

RNA activation (RNAa) is the process of enhancing selective gene expression at transcriptional level using double-stranded RNAs, targeting gene promoter. These RNA molecules are usually 21 nucleotides long and termed as small activating RNAs (saRNAs). They are involved in gene regulation, epigenetics, gain-of-function studies and have potential therapeutic applications for various diseases especially cancer. RNAa is opposite to RNA interference in functionality; however, both processes share some protein machinery. There are many RNA interference centered online resources but no one for saRNAs; therefore, we developed "saRNAdb" database (http://bioinfo.imtech.res.in/manojk/sarna/). It contains 2150 manually curated saRNA entries with detailed information about their nucleotide sequences, activities, corresponding target gene, promoter and other experimental data. Besides, saRNA-promoter binding location, predicted saRNA features, tools (off-target, map) and RNAa-related proteins with their interacting partners are provided. saRNAdb is expected to assist in RNA research especially for nucleic acid-based therapeutics development.

Hypoxia-induced and HIF1α-VEGF-mediated tight junction dysfunction in choriocarcinoma cells: Implications for preeclampsia

INTRODUCTION

Accumulated data indicate that placental hypoxia is implicated in the pathogenesis of preeclampsia (PE). Tight junction (TJ) is important structure that sustains normal placental barrier function, its dysregulation under hypoxia has been observed. This study was designed to explore hypoxia-induced TJ dysfunction in trophoblast cells and its possible involvement in PE pathophysiology.

METHODS

Choriocarcinoma cells were grown in a monolayer and treated with cobalt chloride (CoCl₂) to induce hypoxia. TJ architecture was assessed using transmission electron microscopy, and locations of TJ proteins were determined by immunofluorescence. TJ functions were assessed by transepithelial electrical resistance (TER) and increased cell paracellular permeability (CPP), and the expression of TJ-related proteins, HIF-1α and VEGF was measured.

RESULTS

The TJ functions of trophoblast cells were significantly altered by hypoxia; TER decreased and CPP increased in a time- and concentration-dependent manner. Significant alterations in TJ protein expression and increases in HIF1α and VEGF expression were observed in hypoxic cells, and these effects were attenuated by pretreatment with YC-1. Moreover, corresponding changes in TJ protein expression were also detected in preeclamptic placentas.

CONCLUSION

These data demonstrate that trophoblast cells undergo significant changes in TJ protein expression under hypoxic conditions and highlight the potential significance of the HIF1α-VEGF axis in the regulation of TJ structure and function in the preeclamptic placenta.