EGFL7 gene expression is regulated by hypoxia in trophoblast and altered in the plasma of patients with early preeclampsia

Overexpression of EGFL7 promotes angiogenesis and nerve regeneration in peripheral nerve injury

Peripheral nerve injury (PNI) often leads to significant functional impairment. Here, we investigated the impact of epidermal growth factor-like domain-containing protein 7 (EGFL7) on angiogenesis and nerve regeneration following PNI. Using a sciatic nerve injury model, we assessed nerve function using the sciatic nerve function index. We analyzed the expression levels of EGFL7, forkhead box proteins A1 (FOXA1), nerve growth factor (NGF), brain-derived neurotrophic factors (BDNF), Neurofilament 200 (NF200), myelin protein zero (P0), cell adhesion molecule 1 (CD31), vascular endothelial growth factor (VEGF), and NOTCH-related proteins in tissues and cells. Cell proliferation, migration, and angiogenesis were evaluated through cell counting kit assays, 5-ethynyl-2'deoxyuridine staining, and Transwell assays. We investigated the binding of FOXA1 to the EGFL7 promoter using dual-luciferase assays and chromatin immunoprecipitation. We observed decreased EGFL7 expression and increased FOXA1 expression in PNI, and EGFL7 overexpression alleviated gastrocnemius muscle atrophy, increased muscle weight, and improved motor function. Additionally, EGFL7 overexpression enhanced Schwann cell and endothelial cell proliferation and migration, promoted tube formation, and upregulated NGF, BDNF, NF200, P0, CD31, and VEGF expression. FOXA1 was found to bind to the EGFL7 promoter region, inhibiting EGFL7 expression and activating the NOTCH signaling pathway. Notably, FOXA1 overexpression counteracted the effects of EGFL7 on Schwann cells and endothelial cells. In conclusion, EGFL7 holds promise as a therapeutic molecule for treating sciatic nerve injury.

Carbonic anhydrase 2 is important for articular chondrocyte function and metabolic homeostasis

OBJECTIVES

Aberrant chondrocyte metabolism significantly contributes to cartilage degeneration and osteoarthritis (OA) genesis. However, the mechanisms driving the metabolic shift in OA chondrocytes remain unclear. Interestingly, carbonic anhydrase 2 (CA2) is implicated in metabolic regulation, and its expression dramatically increases in OA chondrocytes, but its exact role and mechanism are poorly understood. This study investigates the mechanistic role of CA2 in chondrocyte metabolic homeostasis under hypoxic and inflammatory conditions.

METHODS

RNA-seq was performed on CA2-deficient C28/I2 cells to identify pathways affected by the loss of CA2 function. We examined CA2's impact on chondrocyte metabolism, anabolism, and catabolism using C28/I2 cells and primary chondrocytes under normoxia and hypoxia and in a model of inflammatory OA.

RESULTS

RNA-seq revealed enrichment of glycolysis, apoptosis, and TNF signaling pathways in CA2-deficient cells. Under hypoxia, CA2 expression increased 10-fold in a HIF-1α-independent manner. Knockdown of CA2 reduced extracellular lactate production, increased ADP/ATP ratio, impaired glycolysis, reduced glycolytic capacity, and lowered expression of glycolysis rate-limiting enzymes but did not disrupt pHi and ROS production. CA2 deficiency altered chondrocyte anabolic and catabolic equilibrium by affecting PI3K/AKT and RELA/p65 signaling. CA2-deficient chondrocytes displayed impeded migration, suppressed proliferation, and cell cycle arrest at the G0/G1 phase. Forced expression of CA2 stabilized chondrocyte metabolism and restored cellular functions.

CONCLUSIONS

Our research uncovered a hitherto unknown mechanistic role for CA2 in regulating chondrocyte energy metabolism and inflammation, underscoring its potential as a critical mediator in OA pathogenesis. Further research using a murine model of experimental OA is warranted to capture the functional implications of CA2.

Evaluation Of Epidermal Growth Factor-Like Domain (EGFL7) mRNA Expression and its Protein Level in Preeclampsia

Objectives

To evaluate the mRNA expression of epidermal growth factor-like domain 7 (EGFL7) in maternal blood and its protein level in sera of pregnant women complicated with preeclampsia (PE).

Method

Case-control study involving 25 pregnant women diagnosed with PE (cases) and 25 gestational age-matched normal pregnant women (controls). EGFL7 mRNA expression in normal and PE patients was quantified by (qRT-PCR), and EGFL7 protein level was estimated using ELISA.

Results

The RQ values of EGFL7 in the PE group were significantly higher than in the NC group (P < 0.001). Pregnancies affected with PE showed higher serum EGFL7 protein compared with matched controls (P < 0.001). EGFL7 serum level cutoff value ≥ 38.25 µg/ml could be used in the diagnosis of PE with sensitivity = 92%, and specificity = 88%.

Conclusion

EGFL7 mRNA is overexpressed in maternal blood of pregnancies complicated with preeclampsia. Serum EGFL7 protein is elevated in PE cases and can be used as a diagnostic marker for preeclampsia.

The epidermal growth factor receptor in healthy pregnancy and preeclampsia

The epidermal growth factor receptor (EGFR) is expressed robustly in the placenta, and critical processes of pregnancy such as placental growth and trophoblast fusion are dependent on EGFR function. However, the role that aberrant EGFR signaling might play in the etiology and/or maintenance of preeclampsia (PE) remains largely unexplored. Recently, we have shown that overexpression of EGFR in cultured uterine artery endothelial cells (UAEC), which express little endogenous EGFR, remaps responsiveness away from vascular endothelial growth factor receptor (VEGFR) signaling and toward EGFR, suggesting that endothelial EGFR expression may be kept low to preserve VEGFR control of angiogenesis. Here we will consider the evidence for the possibility that the endothelial dysfunction observed in PE might in some cases result from elevation of endothelial EGFR. During pregnancy, trophoblasts are known to synthesize large amounts of EGFR protein, and the placenta regularly releases syncytiotrophoblast-derived exosomes and microparticles into the maternal circulation. Although there are no reports of elevated EGFR gene expression in preeclamptic endothelial cells, the ongoing shedding of placental vesicles into the vascular system raises the possibility that EGFR-rich vesicles might fuse with endothelium, thereby contributing to the symptoms of PE by interrupting angiogenesis and blocking pregnancy-adapted vasodilatory function.

Influence of maternal obesity on the multi-omics profiles of the maternal body, gestational tissue, and offspring

Epidemiological studies show that obesity during pregnancy affects more than half of the pregnancies in the developed countries and is associated with obstetric problems and poor outcomes. Obesity tends to increase the incidence of complications. Furthermore, the resulting offspring are also adversely affected. However, the molecular mechanisms of obesity leading to poor pregnancy outcomes remain unclear. Omics methods are used for genetic diagnosis and marker discovery. The aim of this review was to summarize the maternal and fetal pathophysiological alterations induced by gestational obesity,identified using multi-omics detection techniques, and to generalize the biological functions and potential mechanisms of the differentially expressed molecules.

RAR-Related Orphan Receptor: An Accelerated Preeclampsia Progression by Activating the JAK/STAT3 Pathway

PURPOSE

To investigate the effect and underlying mechanism of RAR related orphan receptor A (RORA) on preeclampsia (PE).

MATERIALS AND METHODS

Differentially expressed genes (DEGs) in four datasets were obtained by using the Venn diagram method. RORA mRNA and protein expressions were detected by qRT-PCR, western blot, and immunohistochemistry. HTR-8/SVneo cell viability, proliferation, invasion, migration, and angiogenesis were detected by CCK-8 assay, EdU assay, Transwell, wound healing assay, and tube formation assay, respectively. The concentration of Ang-1 in cells was assessed using available ELISA kit. Epithelial-mesenchymal transition, proliferation, and angiogenesis-related proteins were detected by western blot. GSEA analysis were performed for common DEGs, and the expression of enriched pathway-related proteins was also detected.

RESULTS

The expression of RORA was increased in PE tissue and HTR-8/SVneo cells. Silencing RORA could promote the migration, invasion, epithelial-mesenchymal transition, proliferation, and angiogenesis of hypoxia-treated HTR-8/SVneo cells. Mechanistically, RORA contributed to the deterioration of PE by activating the JAK2/STAT3 signaling pathway to promote cell proliferation, migration, invasion, and angiogenesis.

CONCLUSION

RORA was up-regulated in PE and affected HTR-8/SVneo cell proliferation, invasion, migration, apoptosis, and angiogenesis via the JAK2/STAT3 signaling pathway. This provided a novel strategy for the prevention and treatment of PE.

Prenatal hypoxia induced ETBR activation and abnormal ROS signalling in pulmonary artery cells of rat offspring

Pulmonary arterial hypertension is a progressive disorder characterized by remodeling and increased small pulmonary arteries resistance. Endothelin-1 (ET-1) was related to PAH and ET-1 receptors were up-regulated selectively in the lung when exposed to toxic factor hypoxia. However, the role of ET-1 signaling in the pathogenesis of prenatal hypoxia-induced pulmonary abnormalities remains to be elucidated. Pregnant rats were divided into prenatal hypoxia (10.5 % O2 from gestational day 4-21) and control group. Their three-month-old offspring male rats were tested for vascular functions and molecular analysis, DNA methylation was assessed for cellular hypoxia. Functional testing showed that ET-1-mediated vasoconstriction was enhanced, and the expressions of endothelin A receptor/B receptor (ETAR/ETBR), inositol 1,4,5-trisphosphate receptor, type 1, and the sensitivity of calcium channels were increased in the small pulmonary arteries following prenatal hypoxia. q-PCR and DHE staining showed that the expressions of NADPH oxidase 1/4 (Nox1/4) were up-regulated, along with the increased production of superoxide anion. Furthermore, superoxide anion promoted ET-1-mediated pulmonary artery contraction. In the pulmonary artery smooth muscle cell experiments, q-PCR, Western Blot, CCK8 and DHE staining showed that the expressions of ETBR, Nox1/4, and superoxide anion were increased by hypoxia, along with promoted cell proliferation. 2,2,6,6-Tetramethyl-1-piperidinyloxy reversed hypoxia-induced cell proliferation. ETBR antagonist BQ788 inhibited hypoxia-increased expressions of Nox1/4, superoxide anion production, and proliferation of cells. Moreover, methylation analysis indicated that hypoxia decreased the methylation levels of the ETBR promoter in the pulmonary artery smooth muscle cells. The results indicated that prenatal toxic factor hypoxia resulted in abnormal ETBR activation, which enhanced ET-1-mediated vasoconstriction of pulmonary arteries and pulmonary artery smooth muscle cell proliferation through ETBR/Nox1/4-derived ROS pathway.

Placental DNA methylation changes associated with maternal prepregnancy BMI and gestational weight gain

BACKGROUND

Maternal obesity prior to or during pregnancy influences fetal growth, predisposing the offspring to increased risk for obesity across the life course. Placental epigenetic mechanisms may underlie these associations. We conducted an epigenome-wide association study to identify placental DNA methylation changes associated with maternal prepregnancy body mass index (BMI) and rate of gestational weight gain at first (GWG1), second (GWG2), and third trimester (GWG3).

METHOD

Participants of the NICHD Fetal Growth Studies with genome-wide placental DNA methylation (n = 301) and gene expression (n = 75) data were included. Multivariable-adjusted regression models were used to test the associations of 1 kg/m2 increase in prepregnancy BMI or 1 kg/week increase in GWG with DNA methylation levels. Genes harboring top differentially methylated CpGs (FDR P < 0.05) were evaluated for placental gene expression. We assessed whether DNA methylation sites known to be associated with BMI in child or adult tissues, were also associated with maternal prepregnancy BMI in placenta.

RESULTS

Prepregnancy BMI was associated with DNA methylation at cg14568196[EGFL7], cg15339142[VETZ], and cg02301019[AC092377.1] (FDR P < 0.05, P ranging from 1.4 × 10-10 to 1.7 × 10-9). GWG1 or GWG2 was associated with DNA methylation at cg17918270[MYT1L], cg20735365[DLX5], and cg17451688[SLC35F3] (FDR P < 0.05, P ranging from 6.4 × 10-10 to 1.2 × 10-8). Both prepregnancy BMI and DNA methylation at cg1456819 [EGFL7] were negatively correlated with EGFL7 expression in placenta (P < 0.05). Several CpGs previously implicated in obesity traits in children and adults were associated with prepregnancy BMI in placenta. Functional annotations revealed that EGFL7 is highly expressed in placenta and the differentially methylated CpG sites near EGFL7 and VEZT were cis-meQTL targets in blood.

CONCLUSIONS

We identified placental DNA methylation changes at novel loci associated with prepregnancy BMI and GWG. The overlap between CpGs associated with obesity traits in placenta and other tissues in children and adults suggests that epigenetic mechanisms in placenta may give insights to early origins of obesity.