Downregulation of apelin in the human placental chorionic villi from preeclamptic pregnancies

2015 ◽  
Vol 309 (10) ◽  
pp. E852-E860 ◽  
Author(s):  
Liliya M. Yamaleyeva ◽  
Mark C. Chappell ◽  
K. Bridget Brosnihan ◽  
Lauren Anton ◽  
David L. Caudell ◽  
...  

The role of the endogenous apelin system in pregnancy is not well understood. Apelin's actions in pregnancy are further complicated by the expression of multiple forms of the peptide. Using radioimmunoassay (RIA) alone, we established the expression of apelin content in the chorionic villi of preeclamptic (PRE) and normal pregnant women (NORM) at 36–38 wk of gestation. Total apelin content was lower in PRE compared with NORM chorionic villi (49.7 ± 3.4 vs. 72.3 ± 9.8 fmol/mg protein; n = 20–22) and was associated with a trend for lower preproapelin mRNA in the PRE. Further characterization of apelin isoforms by HPLC-RIA was conducted in pooled samples from each group. The expression patterns of apelin peptides in NORM and PRE villi revealed little or no apelin-36 or apelin-17. Pyroglutamate apelin-13 [(Pyr1)-apelin-13] was the predominant form of the peptide in NORM and PRE villi. Angiotensin-converting enzyme 2 (ACE2) activity was higher in PRE villi (572.0 ± 23.0 vs. 485.3 ± 24.8 pmol·mg−1·min−1; n = 18–22). A low dose of ANG II (1 nM; 2 h) decreased apelin release in NORM villous explants that was blocked by the ANG II receptor 1 (AT1) antagonist losartan. Moreover, losartan enhanced apelin release above the 2-h baseline levels in both NORM and PRE villi ( P < 0.05). In summary, these studies are the first to demonstrate the lower apelin content in human placental chorionic villi of PRE subjects using quantitative RIA. (Pyr1)-apelin-13 is the predominant form of endogenous apelin in the chorionic villi of NORM and PRE. The potential mechanism of lower apelin expression in the PRE villi may involve a negative regulation of apelin by ANG II.

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Roberta da Silva Filha ◽  
Sérgio Veloso Brant Pinheiro ◽  
Thiago Macedo e Cordeiro ◽  
Victor Feracin ◽  
Érica Leandro Marciano Vieira ◽  
...  

AbstractIntroduction: Renin angiotensin system (RAS) plays a role in idiopathic nephrotic syndrome (INS). Most studies investigated only the classical RAS axis. Therefore, the aims of the present study were to evaluate urinary levels of RAS molecules related to classical and to counter-regulatory axes in pediatric patients with INS, to compare the measurements with levels in healthy controls and to search for associations with inflammatory molecules, proteinuria and disease treatment. Subjects and methods: This cross-sectional study included 31 patients with INS and 19 healthy controls, matched for age and sex. Patients and controls were submitted to urine collection for measurement of RAS molecules [Ang II, Ang-(1-7), ACE and ACE2] by enzyme immunoassay and cytokines by Cytometric Bead Array. Findings in INS patients were compared according to proteinuria: absent (<150 mg/dl, n = 15) and present (≥150 mg/dl, n = 16). Results: In comparison to controls, INS patients had increased Ang II, Ang-(1-7) and ACE, levels while ACE2 was reduced. INS patients with proteinuria had lower levels of ACE2 than those without proteinuria. ACE2 levels were negatively correlated with 24-h-proteinuria. Urinary concentrations of MCP-1/CCL2 were significantly higher in INS patients, positively correlated with Ang II and negatively with Ang-(1-7). ACE2 concentrations were negatively correlated with IP-10/CXCL-10 levels, which, in turn, were positively correlated with 24-h-proteinuria. Conclusion: INS patients exhibited changes in RAS molecules and in chemokines. Proteinuria was associated with low levels of ACE2 and high levels of inflammatory molecules.


2020 ◽  
Vol 134 (7) ◽  
pp. 747-750 ◽  
Author(s):  
Rhian M. Touyz ◽  
Hongliang Li ◽  
Christian Delles

Abstract Angiotensin converting enzyme 2 (ACE2) is the major enzyme responsible for conversion of Ang II into Ang-(1-7). It also acts as the receptor for severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2, which causes Coronavirus Disease (COVID)-19. In recognition of the importance of ACE2 and to celebrate 20 years since its discovery, the journal will publish a focused issue on the basic science and (patho)physiological role of this multifunctional protein.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Gregory Weber ◽  
Sathnur Pushpakumar ◽  
Utpal Sen

MicroRNAs regulate several physiological processes and are implicated in various pathologies, including hypertension. Previous work indicates miR-132 targets Sirtuin 1 (Sirt1), a histone deacetylase and regulator of epigenetic gene silencing in various cellular processes. Sirt1 is expressed in the kidney; however, its role in hypertensive kidney and whether it is regulated by physiological gaseous molecules, such as hydrogen sulfide (H 2 S), is not known. In this study, we sought to determine the role of miR-132 in regulating Sirt1, Ace2 and At1 in hypertensive kidney and whether H 2 S donor, GYY4137 (GYY), could reverse these effects and mitigates renal dysfunction. Wild-type mice were treated without or with Ang-II (1000 ng/Kg/Min) and GYY (133 μM) for 4 weeks. Quantitative PCR, Western blot, and immunofluorescence assays were performed. Increased expression levels of miR-132 in hypertensive mice (3.79 fold vs control) were reduced in mice receiving GYY treatment (2.43 fold vs control). Sirt1 expression was reduced (-1.15 fold) in Ang-II mice but was upregulated in GYY (1.25 fold) and Ang-II+GYY (1.9 fold) groups. A similar effect was seen with Sirt1 protein where the expression was increased in animals treated with GYY and Ang-II+GYY (1.16, 1.03 respectively) compared to Ang-II (0.47). Ace2 in Ang-II+GYY (0.45) was increased compared to Ang-II (0.17), while At1 was reduced (0.46) compared to Ang-II (0.86). Immunofluorescence showed decreased signal of Sirt1 in the glomerulus in Ang-II mice and increased At1 in the blood vessels surrounding the glomerulus, leading to constriction of renal artery, decreased blood flow, and kidney dysfunction. These effects were alleviated in mice treated with GYY. Our data suggests that upregulation of miR-132 in hypertensive kidney decreases Sirt1 and Ace2 expression, leading to increased Ang-II signaling through the At1 receptor and GYY supplementation reverses these expression patterns, leading to increased blood flow and kidney function.


2005 ◽  
Vol 288 (2) ◽  
pp. F353-F362 ◽  
Author(s):  
Ningjun Li ◽  
Joseph Zimpelmann ◽  
Keding Cheng ◽  
John A. Wilkins ◽  
Kevin D. Burns

ANG converting enzyme (ACE) 2 (ACE2) is a homologue of ACE, which is not blocked by conventional ACE inhibitors. ACE2 converts ANG 1–10 (ANG I) to ANG 1–9, which can be hydrolyzed by ACE to form the biologically active peptide ANG 1–7. ACE2 is expressed in the kidney, but its precise intrarenal localization is unclear, and the role of intrarenal ACE2 in the production of ANG 1–7 is unknown. The present studies determined the relative distribution of ACE2 in the rat kidney and defined its role in the generation of ANG 1–7 in proximal tubule. In microdissected rat nephron segments, semiquantitative RT-PCR revealed that ACE2 mRNA was widely expressed, with relatively high levels in proximal straight tubule (PST). Immunohistochemistry demonstrated ACE2 protein in tubular segments, glomeruli, and endothelial cells. Utilizing mass spectrometry, incubation of isolated PSTs with ANG I (10−6 M) led to generation of ANG 1–7 (sensitivity of detection > 1 × 10−9 M), accompanied by the formation of ANG 1–8 (ANG II) and ANG 1–9. The ACE2 inhibitor DX600 completely blocked ANG I-mediated generation of ANG 1–7. Incubation of PSTs with ANG 1–9 also led to generation of ANG 1–7, an effect blocked by the ACE inhibitor captopril or enalaprilat, but not by DX600. Incubation of PSTs with ANG II or luminal perfusion of ANG II did not result in detection of ANG 1–7. The results indicate that ACE2 is widely expressed in rat nephron segments and contributes to the production of ANG 1–7 from ANG I in PST. ANG II may not be a major substrate for ACE2 in isolated PST. The data suggest that ACE2-mediated production of ANG 1–7 represents an important component of the proximal tubular renin-ANG system.


Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2261
Author(s):  
Nidhi Gupta ◽  
Abhishek Kanojia ◽  
Arpana Katiyar ◽  
Yashwanti Mudgil

Salt stress is considered to be the most severe abiotic stress. High soil salinity leads to osmotic and ionic toxicity, resulting in reduced plant growth and crop production. The role of G-proteins during salt stresses is well established. AGB1, a G-protein subunit, not only plays an important role during regulation of Na+ fluxes in roots, but is also involved in the translocation of Na+ from roots to shoots. N-Myc Downregulated like 1 (NDL1) is an interacting partner of G protein βγ subunits and C-4 domain of RGS1 in Arabidopsis. Our recent in-planta expression analysis of NDL1 reported changes in patterns during salt stress. Based on these expression profiles, we have carried out functional characterization of the AGB1-NDL1 module during salinity stress. Using various available mutant and overexpression lines of NDL1 and AGB1, we found that NDL1 acts as a negative regulator during salt stress response at the seedling stage, an opposite response to that of AGB1. On the other hand, during the germination phase of the plant, this role is reversed, indicating developmental and tissue specific regulation. To elucidate the mechanism of the AGB1-NDL1 module, we investigated the possible role of the three NDL1 stress specific interactors, namely ANNAT1, SLT1, and IDH-V, using yeast as a model. The present study revealed that NDL1 acts as a modulator of salt stress response, wherein it can have both positive as well as negative functions during salinity stress. Our findings suggest that the NDL1 mediated stress response depends on its developmental stage-specific expression patterns as well as the differential presence and interaction of the stress-specific interactors.


2021 ◽  
pp. S177-S194
Author(s):  
J ZLACKÁ ◽  
K STEBELOVÁ ◽  
M ZEMAN ◽  
I HERICHOVÁ

Angiotensin-converting enzyme 2 (ACE2) was identified as a molecule that mediates the cellular entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several membrane molecules of the host cell must cooperate in this process. While ACE2 serves in a membrane receptor-mediating interaction with the surface spike (S) glycoprotein of SARS-CoV-2 located on the virus envelope, enzyme A disintegrin and metalloproteinase 17 (ADAM17) regulates ACE2 availability on the membrane and transmembrane protease serine 2 (TMPRSS2) facilitates virus-cell membrane fusion. Interestingly, ACE2, ADAM17 and TMPRSS2 show a daily rhythm of expression in at least some mammalian tissue. The circadian system can also modulate COVID-19 progression via circadian control of the immune system (direct, as well as melatonin-mediated) and blood coagulation. Virus/ACE2 interaction causes ACE2 internalization into the cell, which is associated with suppressed activity of ACE2. As a major role of ACE2 is to form vasodilatory angiotensin 1-7 from angiotensin II (Ang II), suppressed ACE2 levels in the lung can contribute to secondary COVID-19 complications caused by up-regulated, pro-inflammatory vasoconstrictor Ang II. This is supported by the positive association of hypertension and negative COVID-19 prognosis although this relationship is dependent on numerous comorbidities. Hypertension treatment with inhibitors of renin-angiotensin system does not negatively influence prognosis of COVID-19 patients. It seems that tissue susceptibility to SARS-CoV-2 shows negative correlation to ACE2 expression. However, in lungs of infected patient, a high ACE2 expression is associated with better outcome, compared to low ACE2 expression. Manipulation of soluble ACE2 levels is a promising COVID-19 therapeutic strategy.


2021 ◽  
Author(s):  
Monica Oldani ◽  
Anna Maria Villa ◽  
Marta Manzoni ◽  
Pasquale Melchioretto ◽  
Paolo Parenti ◽  
...  

Abstract In this paper we report the metabolic characterization of two foci, F1 and F3, obtained at the end of Cell Transformation Assay (CTA), performed by treating C3H10T1/2Cl8 mouse embryo fibroblasts with 1 µM CdCl2 for 24 h. The elucidation of cadmium action mechanism can be useful both to improve the in vitro CTA and to yield insights into carcinogenesis. We previously showed that, despite being both completely transformed type III foci, F1 and F3 foci display different morphologies, proliferative behaviors and gene expression patterns. In this work, the metabolism of the two foci was investigated through Seahorse and enzyme activity assays; moreover, mitochondria were studied in confocal microscopy and reactive oxygen species were detected by flow cytometry. Results showed that F1 focus has higher glycolytic and TCA fluxes compared to F3 focus, and a more negative mitochondrial membrane potential (Δψ), so that most ATP synthesis is performed through oxidative phosphorylation. Confocal microscopy showed mitochondria crowded in the perinuclear region. On the other hand, F3 focus showed lower metabolic rates, with ATP mainly produced by glycolysis and damaged mitochondria. On the whole, our results showed that cadmium treatment induced lasting metabolic alterations in both foci. Triggered by the loss of Pasteur effect in F1 focus and by mitochondrial impairment in F3 focus, these alterations lead to a loss of coordination among glycolysis, TCA and oxidative phosphorylation, which leads to malignant transformation.


Author(s):  
Shilpa Asthana ◽  
Bandana Sodhi ◽  
Satish Kumar

Background: Thrombophilia is a disorder of haemostatic system that results in increased tendency of thrombus formation in both venous and arterial vascular system. The thrombotic events are not only restricted to venous thromboembolism but also can cause fetal loss (abortions or recurrent abortions and fetal demise), placental abruption, intrauterine growth restriction and severe pre-eclampsia. This study evaluates the role of administering thromboprophylaxis with heparin and ecosprin to patients with thrombophilia in pregnancy with previous history of adverse obstetric outcomes.Methods: This prospective study was conducted in 60 patients diagnosed with thrombophilia during pregnancy. The objective of the study was to determine the role of administering low dose ecosprin and heparin as thromboprophylaxis in achieving live births in these patients with thrombophilia. All patients included in this study were prophylactically administered low dose ecosprin with either unfractionated heparin (5000 IU s.c, BD) or low molecular weight heparin (40 mg s.c, OD) during pregnancy. Patients were followed up in the antenatal period and the obstetric outcome noted. Comparisons were made between the obstetric outcomes of these patients receiving the aforesaid thromboprophylaxis with those of previous untreated pregnancies during which no ecosprin or heparin had been administered. The data obtained were subjected to statistical analysis using Students ‘t’ test and Chi square analysis. P value <0.05 was considered statistically significant.Results: Fifty nine of the sixty patients with thrombophilia and previous adverse pregnancy outcome who received prophylaxis with ecosprin and heparin during the present pregnancy had live births (98.33%; p <0.0001). Fifty-eight (96.66%) of these patients progressed to term delivery and one (1.67%) pregnancy resulted in a pre-term birth.Conclusions: Present study reveals that prophylaxis with low dose ecosprin and heparin administered to patients with thrombophilia (acquired or inherited) with history of previous adverse obstetric outcome resulted in a positive outcome in terms of a significantly higher number of live births. However, larger studies are needed to further elaborate on the role of thromboprophylaxis in pregnancies with inherited thrombophilia.


Development ◽  
1995 ◽  
Vol 121 (4) ◽  
pp. 993-1004 ◽  
Author(s):  
I.L. Blitz ◽  
K.W. Cho

In order to study the regional specification of neural tissue we isolated Xotx2, a Xenopus homolog of the Drosophila orthodenticle gene. Xotx2 is initially expressed in Spemann's organizer and its expression is absent in the ectoderm of early gastrulae. As gastrulation proceeds, Xotx2 expression is induced in the overlying ectoderm and this domain of expression moves anteriorly in register with underlying anterior mesoderm throughout the remainder of gastrulation. The expression pattern of Xotx2 suggests that a wave of Xotx2 expression (marking anterior neurectoderm) travels through the ectoderm of the gastrula with the movement of underlying anterior (prechordal plate) mesoderm. This expression of Xotx2 is reminiscent of the Eyal-Giladi model for neural induction. According to this model, anterior neural-inducing signals emanating from underlying anterior mesoderm transiently induce anterior neural tissues after vertical contact with the overlying ectoderm. Further patterning is achieved when the ectoderm receives caudalizing signals as it comes in contact with more posterior mesoderm during subsequent gastrulation movements. Functional characterization of the Xotx2 protein has revealed its involvement in differentiation of the anterior-most tissue, the cement gland. Ectopic expression of Xotx2 in embryos induces extra cement glands in the skin as well as inducing a cement gland marker (XAG1) in isolated animal cap ectoderm. Microinjection of RNA encoding the organizer-specific homeo-domain protein goosecoid into the ventral marginal zone results in induction of the Xotx2 gene. This result, taken in combination with the indistinguishable expression patterns of Xotx2 and goosecoid in the anterior mesoderm suggests that Xotx2 is a target of goosecoid regulation.


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