Endothelin-1 Gene Expression Research Articles

Sex-specific role for the clock protein PER1 in renal ET-1 regulation in salt-sensitive hypertension

Global knockout (KO) of the clock protein PERIOD1 (PER1) in male, but not female, C57BL/6J mice displayed both blunted blood pressure and urinary endothelin-1 (ET-1) rhythms. More recently, we showed that Dahl salt-sensitive (SS) Per1 KO male rats had exacerbated SS hypertension, alongside increased renal injury, renal ET-1 gene ( Edn1) expression, and ET-1 peptide expression from kidneys collected during the rat’s inactive period (2 PM). Additionally, we see increased long non-coding RNA EDN1-AS, which has been suggested to modulate ET-1 production. However, it is unknown whether PER1 regulates rhythms of ET-1 in SS rats and whether PER1 regulates ET-1 in a sex-dependent way. The study objective was to test the hypothesis that PER1 negatively regulates renal EDN1-AS and Edn1 to modulate ET-1 in a sex- and time-dependent manner. To test this hypothesis, kidneys were collected during rat’s active period (2 AM) from male and female SS Per1 KO and SS control rats on a normal salt (0.4% NaCl) or 3 weeks high salt (4% NaCl) diet ( N=5-6). Renal ET-1 protein levels were measured by ELISA and semi- and quantitative PCR was performed to quantify the levels of EDN1-AS and Edn1. Renal ET-1 levels were significantly higher at 2 AM than our previously reported data at 2 PM in both SS Per1 KO and control male rats ( p<0.0001). Renal ET-1 levels were significantly increased in male SS Per1 KO rats following a high salt diet ( p=0.0362) but not in females ( p=0.9522). This was also reflected in the Edn1 mRNA levels (male, p=0.0005; female, p=0.0814). EDN1-AS levels were also increased in males ( p=0.0123) but not in females. Interestingly, significant sex differences were seen in EDN1-AS levels, where EDN1-AS levels were higher in males than females following both low and high salt diets, suggesting a potential novel sex-dependent mechanism for ET-1 regulation. Together, these data suggest sex-specific action of PER1 in the regulation of ET-1 in a model of salt-sensitive hypertension. Future work aims to investigate blood pressure and renal injury in female SS Per1 KO rats and whether this apparent negative regulation of ET-1 by PER1 contributes to the SS hypertensive and renal injury phenotype seen in male SS Per1 KO rats. This work was supported by the National Institutes of Health grants R35 HL135749 (to A.S.), R01 342 DK109570 (to M.G. and A.S.), and Department of Veteran Affairs grants I01 BX004024 (to A.S.). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effect of Orthosiphon stamineus Extract on HIF-1Α, Endothelin-1, and VEGFR-2 Gene Expression in NRK-52E Renal Tubular Cells Subjected to Glucotixicity

This study aimed to investigate the impact of Orthosiphon stamineus extract on gene expression in NRK-52E cells under conditions of glucotoxicity. Gene expression analysis using RT-PCR was conducted following exposure of cultured NRK-52E cells to glucotoxic conditions and various concentrations of Orthosiphon stamineus extract. The results revealed a dose-dependent decrease in HIF-1α, ET-1 and VEGFR-2 gene expression levels upon treatment with Orthosiphon stamineus extract. The diverse array of phytochemicals found within Orthosiphon demonstrates a significant impact on the biochemical pathways implicated in the pathogenesis of the disease. Additionally, molecular docking studies suggested the potential inhibition of Rho-kinase as a mechanistic explanation for this observed effect. These findings suggest that Orthosiphon stamineus extract may possess renoprotective properties against glucotoxicity-induced cellular damage. This study contributes to understanding potential therapeutic interventions for managing renal complications associated with conditions such as diabetes.

Effects of Glucosinolate-Enriched Red Radish (Raphanus sativus) on In Vitro Models of Intestinal Microbiota and Metabolic Syndrome-Related Functionalities.

The gut microbiota profile is determined by diet composition, and therefore this interaction is crucial for promoting specific bacterial growth and enhancing the health status. Red radish (Raphanus sativusL.) contains several secondary plant metabolites that can exert a protective effect on human health. Recent studies have shown that radish leaves have a higher content of major nutrients, minerals, and fiber than roots, and they have garnered attention as a healthy food or supplement. Therefore, the consumption of the whole plant should be considered, as its nutritional value may be of greater interest. The aim of this work is to evaluate the effects of glucosinolate (GSL)-enriched radish with elicitors on the intestinal microbiota and metabolic syndrome-related functionalities by using an in vitro dynamic gastrointestinal system and several cellular models developed to study the GSL impact on different health indicators such as blood pressure, cholesterol metabolism, insulin resistance, adipogenesis, and reactive oxygen species (ROS). The treatment with red radish had an influence on short-chain fatty acids (SCFA) production, especially on acetic and propionic acid and many butyrate-producing bacteria, suggesting that consumption of the entire red radish plant (leaves and roots) could modify the human gut microbiota profile toward a healthier one. The evaluation of the metabolic syndrome-related functionalities showed a significant decrease in the gene expression of endothelin, interleukin IL-6, and cholesterol transporter-associated biomarkers (ABCA1 and ABCG5), suggesting an improvement of three risk factors associated with metabolic syndrome. The results support the idea that the use of elicitors on red radish crops and its further consumption (the entire plant) may contribute to improving the general health status and gut microbiota profile.

Hyperglycemia-induced oxidative stress and epigenetic regulation of ET-1 gene in endothelial cells.

Introduction: Hyperglycemia-induced endothelial dysfunction and the subsequent increase of oxidative stress could lead to aberrant regulation of various genes which are responsible for a range of functions. This study aims to find out how hyperglycemia affect oxidative stress and then the expression and methylation of endothelin 1 (ET-1) gene in in human umbilical vein endothelial cells (HUVEC). Methods: Cells were cultured in growth medium and exposed to low and high glucose concentrations to mimic normal and diabetic condition respectively. Computational analysis were performed using UCSC genome browser and eukaryotic promoter database (EPD). The expression of ET-1 gene was investigated by real time PCR. Cytotoxicity and oxidative stress were determined by MTT and DCFH-DA assays respectively. Promoter methylation was assessed by the bisulfite sequencing method. Results: DCFH-DA assay showed that hyperglycemia can significantly increase the regulation of reactive oxygen species synthesis. The relative expression of ET-1 gene was increased due to exposure to high glucose concentration. MTT assay revealed reduced viability of cells due to the glucose induced damage. Methylation analysis revealed hypomethylation of the promoter of ET-1 however the difference was not significant. Out of 175 CpGs at 25 CpG sites, only 36 CpGs were methylated (20.5% methylation) in cell treated with normal glucose. Upon exposure to high glucose only 30 CpGs were methylated in 175 CpGs at 25 CpG sites (17.1% methylation). Discussion: Our study concludes a significantly high expression of ET-1 gene in response to high glucose exposure in HUVECs. It also reports that hyperglycemic condition leads to elevated oxidative stress. No significant change was found in methylation when cells were treated with high and low glucose concentrations.

Circulatory Maternal Endothelin 1 and Matrix Metalloproteinase-9 Gene Expression in PREECLAMPSIA: A Study in Western Uttar Pradesh, India.

Preeclampsia (PE) is a multiorgan disease of pregnant women. The main pathophysiology of PE is a trophoblastic invasion into maternal circulation leading to alterations in circulatory levels of matrix metalloproteinases (MMPs), inflammatory markers, and endothelin 1(ET1) levels. Therefore, the present study has explored the role of MMP-9 and ET1 and their association in PE. The advantage of the study is to provide insight into the pathology of PE. These markers may help in the early diagnosis and prognosis of PE. To investigate MMP-9 gene expression, ET1 level in PE cases and their correlation with blood pressure (BP), gestational age, weight, and height. The study design was a case-control observational study, which included 70 subjects in each case (PE) and controls (normal pregnant women (NPW)). Whole blood (250 ul) was utilized for RNA extraction (Trizol method) and synthesized cDNA as per manufacturer protocol. MMP-9 gene expression was analyzed by real-time PCR. Serum was utilized for ET1 estimation by sandwich ELISA. The ET1 levels and MMP-9 gene expression were significantly increased in preeclamptic women as compared to controls. There was no significant correlation between MMP-9 gene expression and serum ET1 levels. However, a significant moderate association between systolic BP and diastolic BP with ET1 levels and MMP9 gene expression was seen in both PE and NPW. A significantly increased circulatory concentration of ET1 and MMP-9 gene expression in PE might be used as an early diagnostic as well as a prognostic marker of PE.

Quantification of Endothelin-1 Gene Expression in the Diabetic Patients' Type II (DMT2) with Cardiovascular Disease

The goal of this study is to see if there's a link between diabetes type 2 problems and endothelin-1 overexpression (ET-1). Where (90) blood samples from participants were obtained and divided into three groups: a first group representing individuals with (Hypertensive DMT2) and a second group representing (Hypertensive DMT2with CVD,), while the third group was represented by a control group. mRNA was extracted from blood samples then converted to cDNA by using the (qPCR) technique. When comparing the levels of ET-1 in the (hypertensive DMT2 and hypertensive DMT2with CVD groups ) to the control group, the results showed a significant difference (p<0.05), The current study analyzed the ET-1 gene in type 2 diabetes and cardiovascular disease, which could be a new target for early CVD therapy in the future. Keywords: endothelin-1gene, diabetes type II, cardiovascular disease, , endothelial dysfunction

Vascularized pancreas-on-a-chip device produced using a printable simulated extracellular matrix

The extracellular matrix (ECM) influences cellular behavior, function, and fate. The ECM surrounding Langerhans islets has not been investigated in detail to explain its role in the development and maturation of pancreatic β-cells. Herein, a complex combination of the simulated ECM (sECM) has been examined with a comprehensive analysis of cell response and a variety of controls. The most promising results were obtained from group containing fibrin, collagen type I, Matrigel®, hyaluronic acid, methylcellulose, and two compounds of functionalized, ionically crosslinking bacterial cellulose (sECMbc). Even though the cell viability was not significantly impacted, the performance of group of sECMbc showed 2 to 4× higher sprouting number and length, 2 to 4× higher insulin secretion in static conditions, and 2 to 10× higher gene expression of VEGF-A, Endothelin-1, and NOS3 than the control group of fibrin matrix (sECMf). Each material was tested in a hydrogel-based, perfusable, pancreas-on-a-chip device and the best group—sECMbc has been tested with the drug Sunitinib to show the extended possibilities of the device for both diabetes-like screening as well as PDAC chemotherapeutics screening for potential personal medicine approach. It proved its functionality in seven days dynamic culture and is suitable as a physiological tissue model. Moreover, the device with the pancreatic-like spheroids was 3D bioprintable and perfusable.

The EDN1 Missense Variant rs5370G > T Regulates Adaptation and Maladaptation under Hypobaric Hypoxia.

Endothelin 1 (EDN1) encodes a potent endogenous vasoconstrictor, ET1, to maintain vascular homeostasis and redistribution of tissue blood flow during exercise. One of the EDN1 missense polymorphisms, rs5370 G/T, has strongly been associated with cardiopulmonary diseases. This study investigated the impact of rs5370 polymorphism in high-altitude pulmonary oedema (HAPE) disorder or maladaptation and adaptation physiology in a well-characterized case–control study of high-altitude and low-altitude populations comprising 310 samples each of HAPE-patients, HAPE-free controls and native highlanders. The rs5370 polymorphism was genotyped, and the gene expression and plasma level of EDN1 were evaluated. The functional relevance of each allele was investigated in the human embryonic kidney 293 cell line after exposure to hypoxia and computationally. The T allele was significantly more prevalent in HAPE-p compared to HAPE-f and HLs. The EDN1 gene expression and ET1 bio-level were significantly elevated in HAPE-p compared to controls. Compared to the G allele, the T allele was significantly associated with elevated levels of ET-1 in all three study groups and cells exposed to hypoxia. The in silico studies further confirmed the stabilizing effect of the T allele on the structural integrity and function of ET1 protein. The ET1 rs5370 T allele is associated with an increased concentration of ET-1 in vivo and in vitro, establishing it as a potent marker in the adaptation/maladaptation physiology under the high-altitude environment. This could also be pertinent in endurance exercises at high altitudes.

Reactive oxygen species mediate oxidized low-density lipoprotein-induced endothelin-1 gene expression via extracellular signal-regulated kinase in vascular endothelial cells: Retraction.

Reactive oxygen species mediate oxidized low-density lipoprotein-induced endothelin-1 gene expression via extracellular signal-regulated kinase in vascular endothelial cells: Retraction.

Hypoxia Regulates Endothelin‐1 Production and Microglial Cell Activation

Oxidative stress and inflammatory responses play critical roles in hypoxic‐ischemic brain injury.Microglial cells are rapidly activated in response to injury and stressful stimuli, including hypoxia.Endothelin‐1 (ET‐1) is a potent vasoconstrictor that has been associated with cerebrovascular diseases. Hypoxia stimulates endothelial ET‐1 production. However, the role of ET‐1 in microglia under hypoxia is not clear. The aim of this project was to characterize the effect of hypoxia in a human microglial cell line, HMC3. We induced hypoxia using a chamber (1% O2, 5% CO2, and 92 % N2) at 37 °C for 4h. MUSE Oxidative Stress Assay was performed to measure reactive oxygen species (ROS) formation, ELISA to determine TNF, IL‐6, and ET‐1 levels, qPCR to measure gene expression of ET‐1, and immunofluorescence staining to visualize and compare the presence of ET‐1 in hypoxic and controlgroup cells. It was observed that, when compared to normoxic HMC3 cells, hypoxic HMC3 exposure significantly increased the ROS by a factor of 2.5 (p<0.001, n=3), the pro‐inflammatory cytokine TNF‐α increased 3.8 times (p<0.01, n=4), and IL‐6 increased by a factor of 1.6 (p<0.01, n=4). In addition, hypoxia stimulates ET‐1 gene expression 5.0‐fold (p<0.001, n=4) and increased protein production 1.3 times (p<0.01, n=4). Consequently, treatment with ET‐1 increased the amount of ROS, TNF‐α, and IL‐6 in HMC3 cells by a factor of 1.4 (p<0.05, n=4), 1.6 (p<0.001, n=4), and 1.9 (p<0.05, n=4), respectively. All these events were blocked by ET‐1 receptor A (ETRA) antagonist, BQ123. Our results suggest that hypoxic conditions create a cycle of microglial cell activation leading to increased ROS and ET‐1 production that further stimulate microglial cells. Thus, we posit that the ET‐1 receptor blockade represents a promising therapeutic approach to regulate microglial cell responses in hypoxic‐ischemic brain injury.

Vascular reactivity contributes to adipose tissue remodeling in obesity.

Vascular reactivity of adipose tissue (AT) is hypothesized to play an important role in the development of obesity. However, the exact role of vascular reactivity in the development of obesity remains unclear. In this study, we investigated the chronological changes in vascular reactivity and the microenvironments of the visceral AT (VAT) and subcutaneous AT (SAT) in lean and obese mice. Changes in blood flow levels induced by a β-adrenoceptor agonist (isoproterenol) were significantly lower in the VAT of the mice fed a high-fat diet (HFD) for 1 and 12 weeks than those in the VAT of the mice fed a low-fat diet (LFD) for the same period; no significant change was observed in the SAT of any mouse group, suggesting depot-specific vascular reactivity of AT. Moreover, the hypoxic area and the expression of genes associated with angiogenesis and macrophage recruitment were increased in the VAT (but not in the SAT) of mice fed an HFD for 1 week compared with mice fed an LFD. These changes occurred with no morphological changes, including those related to adipocyte size, AT vessel density, and the diameter and pericyte coverage of the endothelium, suggesting a determinant role of vascular reactivity in the type of AT remodeling. The suppression of vascular reactivity was accompanied by increased endothelin1 (Edn1) gene expression and extracellular matrix (ECM) stiffness only in the VAT, implying enhanced contractile activities of the vasculature and ECM. The results suggest a depot-specific role of vascular reactivity in AT remodeling during the development of obesity.

Abstract 12114: Endothelial Extracellular Signal-Regulated Kinase 2 Contributed to the Development of Pulmonary Arterial Hypertension in Mice Through the Impairment of Endothelial Nitric Oxide Synthase Function

Introduction: Pulmonary arterial hypertension (PAH) is a progressive disease, characterized by abnormal muscularization and endothelial dysfunction in pulmonary artery (PA). Previous study showed that endothelial extracellular signal-regulated kinase 2 (eERK2) released vasoconstrictive factors and decreased NO bioactivity resulting in obese-induced hypertension and endothelial dysfunction. However, the role of eERK2 in the pathogenesis of PAH remains to be elucidated. Hypothesis: We hypothesized eERK2 impaired eNOS function and progressed the pathogenesis of PAH. Methods and Results: We generated eERK2 knock out mice (EE2KO) crossing Tie2-Cre mice and ERK2 flox mice and induced PAH by exposing mice to chronic hypoxia (10%) for 4 weeks. The littermate ERK2 flox mice without Cre expression were used as Control (Ctr). Immuno-histochemical staining showed the deficiency of eERK2 expression in the PA of EE2KO. We assessed the medial thickness of pulmonary arteries (MTPA) and measured right ventricular systolic pressure (RVSP). Although Ctr exhibited the progression of PA muscularization with an increase in MTPA, EE2KO revealed the significantly attenuated MTPA under hypoxic condition. Moreover, we found the lower RVSPs in EE2KO than those in Ctr under hypoxia in spite of similar RVSPs in normoxia. In RT-PCR, lung endothelin1 (ET1) gene expression was significantly lower in EE2KO than Ctr under hypoxia. Interestingly, hypoxia increased eNOS protein expression both in Ctr and EE2KO with Western blot analysis. The phosphorylation of AMPKα and eNOS were up-regulated in the lungs of EE2KO relative to Ctr under hypoxia. In addition, eNOS dimer/monomer ratios with non redusing SDS-PAGE was significantly increased in EE2KO compared to the Ctr under hypoxia (1.29±0.10 vs. 0.87±0.02, P=0.02, dimer / monomer ratios), suggesting improved eNOS uncoupling. Conclusions: These findings suggest that hypoxia increased eNOS expression and function, and that eERK2 impaired eNOS function by decreasing the phosphorylation of AMPKα and eNOS, and inducing eNOS uncoupling. In addition, ET1 synthesis through eERK2 might contribute to these pathogenesis of PAH with hypoxia.

Endothelin receptors in renal interstitial cells do not contribute to the development of fibrosis during experimental kidney disease

Renal interstitial fibrosis is characterized by the development of myofibroblasts, originating from resident renal and immigrating cells. Myofibroblast formation and extracellular matrix production during kidney damage are triggered by various factors. Among these, endothelins have been discussed as potential modulators of renal fibrosis. Utilizing mouse models of adenine nephropathy (AN) and unilateral ureter occlusion (UUO), this study aimed to investigate the contribution of endothelin signaling in stromal mesenchymal resident renal interstitial cells. We found in controls that adenine feeding and UUO caused marked upregulations of endothelin-1 (ET-1) gene expression in endothelial and in tubular cells and a strong upregulation of ETA-receptor (ETA-R) gene expression in interstitial and mesangial cells, while the gene expression of ETB-receptor (ETB-R) did not change. Conditional deletion of ETA-R and ETB-R gene expression in the FoxD1 stromal cell compartment which includes interstitial cells significantly reduced renal ETA-R gene expression and moderately lowered renal ETB-R gene expression. ET receptor (ET-R) deletion exerted no apparent effects on kidney development nor on kidney function. Adenine feeding and UUO led to similar increases in profibrotic and proinflammatory gene expression in control as well as in ETAflflETBflfl FoxD1Cre+ mice (ET-Ko). In summary, our findings suggest that adenine feeding and UUO activate endothelin signaling in interstitial cells which is due to upregulated ETA-R expression and enhanced renal ET-1 production Our data also suggest that the activation of endothelin signaling in interstitial cells has less impact for the development of experimentally induced fibrosis.

TLR4-Endothelin Axis Controls Syncytiotrophoblast Motility and Confers Fetal Protection in Placental Malaria.

Pregnancy-associated malaria is often associated with adverse pregnancy outcomes. Placental circulatory impairments are an intriguing and unsolved component of malaria pathophysiology. Here, we uncovered a Toll-like receptor 4 (TLR4)-TRIF-endothelin axis that controls trophoblast motility and is linked to fetal protection during Plasmodium infection. In a cohort of 401 pregnancies from northern Brazil, we found that infection during pregnancy reduced expression of endothelin receptor B in syncytiotrophoblasts, while endothelin expression was only affected during acute infection. We further show that quantitative expression of placental endothelin and endothelin receptor B proteins are differentially controlled by maternal and fetal TLR4 alleles. Using murine malaria models, we identified placental autonomous responses to malaria infection mediated by fetally encoded TLR4 that not only controlled placental endothelin gene expression but also correlated with fetal viability protection. In vitro assays showed that control of endothelin expression in fetal syncytiotrophoblasts exposed to Plasmodium-infected erythrocytes was dependent on TLR4 via the TRIF pathway but not MyD88 signaling. Time-lapse microscopy in syncytiotrophoblast primary cultures and cell invasion assays demonstrated that ablation of TLR4 or endothelin receptor blockade abrogates trophoblast collective motility and cell migration responses to infected erythrocytes. These results cohesively substantiate the hypothesis that fetal innate immune sensing, namely, the TRL4-TRIF pathway, exerts a fetal protective role during malaria infection by mediating syncytiotrophoblast vasoregulatory responses that counteract placental insufficiency.

Allicin Could Potentially Alleviate Oral Cancer Pain by Inhibiting "Pain Mediators" TNF-alpha, IL-8, and Endothelin.

To evaluate the effects of allicin on mediators of pain secreted by oral cancer cells in vitro, single-cell suspensions were prepared by enzymatic method from oral squamous cell carcinoma (OSCC). Cancer stem cells were isolated by the CD133+ selection method with magnetic cell sorting. Stemness markers were checked in both cancer cells and cancer stem cells by RT-PCR. Comparative analysis of pain mediators TNF-alpha, IL-8, and endothelin at both RNA and protein levels for normal epithelial cells, cancer cells, and cancer stem cells was carried out with and without allicin treatment. CD133 and CD44 expression levels were checked in cancer cells and cancer stem cells flow cytometrically. Allicin inhibited both gene and protein expression of TNF-alpha, IL-8, and endothelin in both cancer cells and cancer stem cells. Allicin is more likely to be a promising treatment in alleviating the levels of pain and inflammation in OSCCs.

Signal Crosstalk Promoted Proliferative Lesions in Mouse Mammary Glands As a Consequence of ET-1 Overexpression

Objective: As a distinct cellular signaling model, a receptor crosstalk between G protein-coupled receptors (GPCR) and epidermal growth factor receptor (EGFR) has been demonstrated in various in vitro studies. In addition, recent in vitro studies had focused on the signaling pathways of endothelin-1 (ET-1) in the pathophysiology of cancer. Accordingly, a growing interest in the analysis of the receptor crosstalk between ET-1 receptors and EGFR and functional consequences of EGFR activation of proliferative diseases evoked us to the analysis of this phenomenon in vivo. Materials and Methods: We performed a comparative study between ET-1 transgenic mice and control mice during the late pregnancy (n=7), early lactation (n=6) the mid of lactation (n=10) and involution day 14 (n=7) periods. Hematoxylin and eosin (HE)- stained parallel sections from mammary glands were microscopically examined. The key signal proteins (ETAR, ETBR, ERK1/2, pEGFR) in transactivation of EGFR were analyzed employing Western blot techniques. Genes (amphiregulin, TGFa, EGF, HB-EGF, ADAM 17) known to play an important role in these activities were analyzed using real-time PCR (RT-PCR) techniques. Results: ET-1 transgenic mice exhibited hyperproliferative lesions (lactational hyperplasia) during the middle of the lactation period. Our RT-PCR analyses showed a prominent up regulation of amphiregulin and ADAM 17 in ET-1 transgenic mice. Moreover, we found higher EGFR and ERKs activations in the transgenic mammary glands. Conclusion: This study highlights a causative effect of upregulated ET-1 gene expression on the induction of proliferative lesions via EGFR transactivation in mammary glands. Further, ET-1 overexpression induced an upregulation of amphiregulin and ADAM17 expressions in the transgenic mammary glands. These results suggests that the enhanced ET-1 gene expression and its receptors might have a crucial role in proliferative diseases maintaining EGFR activation.

ERN1 knockdown modifies the impact of glucose and glutamine deprivations on the expression of EDN1 and its receptors in glioma cells.

Objective. The aim of the present investigation was to study the impact of glucose and gluta-mine deprivations on the expression of genes encoding EDN1 (endothelin-1), its cognate receptors (EDNRA and EDNRB), and ECE1 (endothelin converting enzyme 1) in U87 glioma cells in response to knockdown of ERN1 (endoplasmic reticulum to nucleus signaling 1), a major signaling pathway of endoplasmic reticulum stress, for evaluation of their possible implication in the control of glioma growth through ERN1 and nutrient limitations. Methods. The expression level of EDN1, its receptors and converting enzyme 1 in control U87 glioma cells and cells with knockdown of ERN1 treated by glucose or glutamine deprivation by quantitative polymerase chain reaction was studied. Results. We showed that the expression level of EDN1 and ECE1 genes was significantly up-regulated in control U87 glioma cells exposure under glucose deprivation condition in comparison with the glioma cells, growing in regular glucose containing medium. We also observed up-regulation of ECE1 gene expression in U87 glioma cells exposure under glutamine deprivation as well as down-regulation of the expression of EDN1 and EDNRA mRNA, being more significant for EDN1. Furthermore, the knockdown of ERN1 signaling enzyme function significantly modified the response of most studied gene expressions to glucose and glutamine deprivation conditions. Thus, the ERN1 knockdown led to a strong suppression of EDN1 gene expression under glucose deprivation, but did not change the effect of glutamine deprivation on its expression. At the same time, the knockdown of ERN1 signaling introduced the sensitivity of EDNRB gene to both glucose and glutamine deprivations as well as completely removed the impact of glucose deprivation on the expression of ECE1 gene. Conclusions. The results of this study demonstrated that the expression of endothelin-1, its receptors, and ECE1 genes is preferentially sensitive to glucose and glutamine deprivations in gene specific manner and that knockdown of ERN1 significantly modified the expression of EDN1, EDNRB, and ECE1 genes in U87 glioma cells. It is possible that the observed changes in the expression of studied genes under nutrient deprivation may contribute to the suppressive effect of ERN1 knockdown on glioma cell proliferation and invasiveness.

Abstract MP15: Hypoxia and Endothelin-1 in Microglial Cell Activation

Oxidative stress and inflammatory responses play critical roles in hypoxic-ischemic brain injury. Microglial cells are rapidly activated in response to injury and stressful stimuli, including hypoxia. Endothelin-1 (ET-1) is a potent vasoconstrictor that has been associated with cerebrovascular diseases. Hypoxia stimulates endothelial ET-1 production. However, the role of ET-1 in microglia under hypoxia is not clear. The aim of this project was to characterize the effect of hypoxia in a human microglial cell line, HMC3. We induced hypoxia using a chamber (1% O2, 5% CO2, and 92 % N2) at 37 °C for 4h, 24h, and 48h. MUSE Oxidative Stress Assay was performed to measure reactive oxygen species (ROS) formation, ELISA to determine TNF, IL-6, and ET-1 levels, qPCR to measure gene expression of ET-1, and immunofluorescence staining to visualize and compare the presence of ET-1 in hypoxic and control group cells. It was observed that, when compared to normoxic HMC3 cells, hypoxic HMC3 exposure significantly increased the ROS by a factor of 2.5 (p<0.001, n=3), the pro-inflammatory cytokine TNF-α increased 3.8 times (p<0.01, n=4), and IL-6 increased by a factor of 1.6 (p<0.01, n=4). In addition, hypoxia stimulates ET-1 gene expression 5.0-fold (p<0.001, n=4) and increased protein production 1.3 times (p<0.01, n=4). Consequently, treatment with ET-1 increased the amount of ROS, TNF-α, and IL-6 in HMC3 cells by a factor of 1.4 (p<0.05, n=4), 1.6 (p<0.001, n=4), and 1.9 (p<0.05, n=4), respectively. All these events were blocked by ET-1 receptor A (ETRA) antagonist, BQ123. Our results suggest that hypoxic conditions create a cycle of microglial cell activation leading to increased ROS and ET-1 production that further stimulate microglial cells. Thus, we posit that the ET-1 receptor blockade represents a promising therapeutic approach to regulate microglial cell responses in hypoxic-ischemic brain injury.

Preeclampsia: inflammatory signature of decidual cells in early manifestation of disease

IntroductionPreeclampsia is a pregnancy-specific complication characterized by hypertension in combination with proteinuria and/or various manifestations of multiple organ failure. It is believed that etiology of preeclampsia lies in dysfunction of the placenta and disorder of the maternal-fetal interactions. In preeclampsia decidual membrane, the maternal part of the placenta which normally supports immunological tolerance of the maternal organism to the semi-allogeneic fetus, becomes a site of inflammation. MethodsThe aim of our study was to characterize the phenotype of decidual macrophages and plasma profiles in patients with late- and early-onset preeclampsia as compared with controls (n = 43). Decidual cells were obtained by enzymatic digestion method and characterized by flow cytometry analysis, real-time PCR, bioinformatics analysis, immunohistochemistry, and Western blot. Plasma samples were analyzed by multiplex assay. ResultsThe number of inflammation-associated CD86+ and CX3CR1+ cells was significantly higher in the early-onset preeclampsia while the portion of CD163+ cells was significantly higher among studied groups. We observed significant increase of endothelin-1 gene expression and a significant decrease in eNOS and GNB3 expression and TGFβ relative protein level in decidual cells of the early-onset preeclampsia samples. We also revealed elevation of pro- and anti-inflammatory cytokines in plasma of preeclampsia groups. DiscussionOur findings reflect profound early-onset preeclampsia-associated alterations in the decidua and emphasize the importance of the decidua as a link in the development of preeclampsia.

NOD2 induces VCAM-1 and ET-1 gene expression via NF-κB in human umbilical vein endothelial cells with muramyl dipeptide stimulation.

Endothelial dysfunction is involved in various aspects of vascular biology and different stages of cardiovascular diseases (CVDs). Nucleotide-binding oligomerization domain-containing protein (NOD)2, apivotal innate immune receptor for muramyl dipeptide (MDP), has been reported to be acentral regulator in CVDs. Previously, we reported that NOD2 played aleading role in MDP-triggered oxidative stress in endothelial cells (ECs). However, whether NOD2 participates in the regulatory mechanism of vascular cell adhesion molecule‑1 (VCAM-1) and endothelin‑1 (ET-1) expression was not elucidated. Human umbilical vein endothelial cells (HUVECs) were stimulated with MDP for 12 h. mRNA expression of VCAM‑1 and ET‑1 was detected using real time polymerase chain reaction (PCR). Scrambled control small interfering RNA (siRNA) and NOD2 siRNA were transfected into HUVECs using Lipofectamine 2000 reagent (Invitrogen, Waltham, MA, USA). Furthermore, pyrrolidine dithiocarbamate was adopted to investigate the effect of nuclear factor κB (NF-κB) on NOD2-mediated VCAM‑1 and ET‑1 gene expression in MDP-treated HUVECs. Data showed that MDP significantly increased VCAM‑1 and ET‑1 mRNA expression, which was dependent on NOD2. In addition, NF-κB inhibition suppressed NOD2-mediated gene expression of VCAM‑1 and ET‑1. Collectively, we confirmed NOD2 aggravated VCAM‑1 and ET‑1 gene expression through NF-κB in HUVECs treated with MDP.