Angiotensin II induces apoptosis of human right and left ventricular endocardial endothelial cells by activating the AT2 receptor

Endocardial endothelial cells (EECs) form a monolayer lining the ventricular cavities. Studies from our laboratory and the literature have shown differences between EECs isolated from the right and left ventricles (EECRs and EECLs, respectively). Angiotensin II (Ang II) was shown to induce apoptosis of different cell types mainly via AT1 receptor activation. In this study, we verified whether Ang II induces apoptosis of human EECRs and EECLs (hEECRs and hEECLs, respectively) and via which type of receptor. Using the annexin V labeling and in situ TUNEL assays, our results showed that Ang II induced apoptosis of both hEECRs and hEECLs in a concentration-dependent manner. Our results using specific AT1 and AT2 receptor antagonists showed that the Ang-II-induced apoptosis in both hEECRs and hEECLs is mediated mainly via the AT2 receptor. However, AT1 receptor blockade partially prevented Ang-II-induced apoptosis, particularly in hEECRs. Hence, our results suggest that mainly AT2 receptors mediate Ang-II-induced apoptosis of hEECRs and hEECLs. The damage of EECs would affect their function as a physical barrier between the blood and cardiomyocytes, thus affecting cardiomyocyte functions.

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Difference in the response to angiotensin II between left and right ventricular endocardial endothelial cells

Canadian Journal of Physiology and Pharmacology ◽

10.1139/cjpp-2017-0280 ◽

2017 ◽

Vol 95 (10) ◽

pp. 1271-1282 ◽

Cited By ~ 3

Author(s):

Danielle Jacques ◽

Nelly Abdel-Karim Abdel-Malak ◽

Nadia Abou Abdallah ◽

Johny Al-Khoury ◽

Ghassan Bkaily

Keyword(s):

Endothelial Cells ◽

Angiotensin Ii ◽

Right Ventricular ◽

Cell Types ◽

Receptor Activation ◽

Ang Ii ◽

Nuclear Calcium ◽

Endocardial Endothelial Cells ◽

The Right ◽

Higher Sensitivity

Previous studies focused on the right ventricular endocardial endothelial cells (EECRs) and showed that angiotensin II (Ang II) induced increase in cytosolic and nuclear calcium via AT1 receptor activation. In the present study, we verified whether the response of left EECs (EECLs) to Ang II is different than that of EECRs. Our results showed that the EC50 of the Ang II-induced increase of cytosolic and nuclear calcium in EECLs was 10× higher (around 2 × 10−13 mol/L) than in EECRs (around 8 × 10−12 mol/L). The densities of both AT1 and AT2 receptors were also higher in EECLs than those previously reported in EECRs. The effect of Ang II was mediated in both cell types via the activation of AT1 receptors. Treatment with Ang II induced a significant increase of cytosolic and nuclear AT1 receptors in EECRs, whereas the opposite was found in EECLs. In both cell types, there was a transient increase of cytosolic and nuclear AT2 receptors following the Ang II treatment. In conclusion, our results showed that both AT1 and AT2 receptors densities are higher in both EECLs compared to what was reported in EECRs. The higher density of AT1 receptors in EECLs compared to REECs may explain, in part, the higher sensitivity of EECLs to Ang II.

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Cytotoxic Effects of Ferula Latisecta on Human Glioma U87 Cells

Drug Research ◽

10.1055/a-0986-6543 ◽

2019 ◽

Vol 69 (12) ◽

pp. 665-670 ◽

Cited By ~ 6

Author(s):

Mohammad Jalili-Nik ◽

Hamed Sabri ◽

Ehsan Zamiri ◽

Mohammad Soukhtanloo ◽

Mostafa Karimi Roshan ◽

...

Keyword(s):

Enzymatic Activity ◽

Gelatin Zymography ◽

Annexin V ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Ic50 Values ◽

Induced Apoptosis ◽

Natural Herb ◽

First Time ◽

U87 Cells

AbstractGlioblastoma multiforme (GBM) is the fatal type of astrocytic tumors with a survival rate of 12 months. The present study, for the first time, evaluated the cytotoxic impacts of Ferula latisecta (F. latisecta) hydroalcoholic extract on U87 GBM cell line. The MTT assay measured the cellular toxicity following 24- and 48 h treatment with various doses of F. latisecta (0–800 μg/mL). Apoptosis was evaluated by an Annexin V/propidium iodide (PI) staining 24 h after treatment by F. latisecta. Moreover, to determine the cellular metastasis of U87 cells, we used a gelatin zymography assay (matrix metalloproteinase [MMP]-2/-9 enzymatic activity). The outcomes showed that F. latisecta mitigated the viability of U87 cells in a concentration- and time-dependent manner with IC50 values of 145.3 and 192.3 μg/mL obtained for 24- and 48 h treatments, respectively. F. latisecta induced apoptosis in a concentration-dependent manner after 24 h. Also, MMP-9 activity was significantly decreased following 24 h after treatment concentration-dependently with no change in MMP-2 enzymatic activity. This study showed that F. latisecta induced cytotoxicity and apoptosis, and mitigated metastasis of U87 GBM cells. Hence, F. latisecta could be beneficial as a promising natural herb against GBM after further studies.

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Potentiation of angiotensin II-stimulated vascular contraction by lithium

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1995.268.5.h2009 ◽

1995 ◽

Vol 268 (5) ◽

pp. H2009-H2016

Author(s):

M. E. Ullian ◽

L. G. Walsh ◽

K. C. Wong ◽

C. J. Allan

Keyword(s):

Angiotensin Ii ◽

Inositol Phosphate ◽

Cytosolic Calcium ◽

Rat Aorta ◽

Dependent Manner ◽

Ang Ii ◽

Concentration Dependent Manner ◽

Adrenergic Agents ◽

Phosphoinositide Signaling ◽

Protein Kinase C Inhibitor

Previous studies have suggested that lithium prolongs or enhances vascular contractions stimulated by alpha-adrenergic agents. The present study was performed to determine whether a similar phenomenon occurs with angiotensin II (ANG II)-stimulated contractions and whether this phenomenon results from interactions with the phosphoinositide signaling system. Contractions of rat aortic rings with 100 nM ANG II were 38% greater in the presence of 20 mM LiCl than in its absence (0.47 +/- 0.07 vs. 0.34 +/- 0.05 g tension/mg dry tissue wt, P < 0.01). The effects of lithium on inositol phosphate responses, diacylglycerol responses, and intracellular calcium concentration on single or repeated stimulations with ANG II were then examined in vascular smooth muscle cells cultured from rat aorta. Cells exposed twice to 100 nM ANG II contained 50% lower inositol trisphosphate levels (InsP3) and 10% lower diacylglycerol levels than cells exposed to ANG II only once. LiCl or lithium acetate abolished these desensitizations in a concentration-dependent manner. Similarly, InsP3 and diacylglycerol responses to a single exposure of ANG II were heightened by lithium (by 75 and 25%, respectively), and the duration of the responses was prolonged by lithium (5- and 2-fold, respectively). In contrast, ANG II-stimulated calcium transients were not enhanced or prolonged by lithium, nor was desensitization of ANG II-stimulated cytosolic calcium mobilization upon serial exposures abolished by lithium. When ring contraction studies were repeated in the presence of the protein kinase C inhibitor staurosporine (150 nM), lithium no longer potentiated ANG II contractions [0.38 +/- 0.03 (control) vs. 0.35 +/- 0.06 g tension/mg dry tissue wt (lithium)].(ABSTRACT TRUNCATED AT 250 WORDS)

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Intrinsic ANG II type 1 receptor stimulation contributes to recovery of postischemic mechanical function

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1998.274.5.h1524 ◽

1998 ◽

Vol 274 (5) ◽

pp. H1524-H1531 ◽

Cited By ~ 1

Author(s):

William R. Ford ◽

Alexander S. Clanachan ◽

Gary D. Lopaschuk ◽

Richard Schulz ◽

Bodh I. Jugdutt

Keyword(s):

Recovery Of Function ◽

Left Ventricular ◽

Dependent Manner ◽

Mechanical Function ◽

Ang Ii ◽

Concentration Dependent Manner ◽

Proton Production ◽

Rat Hearts ◽

Postischemic Recovery

To determine whether intrinsic angiotensin II (ANG II) type 1 receptor (AT1-R) stimulation modulates recovery of postischemic mechanical function, we studied the effects of selective AT1-R blockade with losartan on proton production from glucose metabolism and recovery of function in isolated working rat hearts perfused with Krebs-Henseleit buffer containing palmitate, glucose, and insulin. Aerobic perfusion (50 min) was followed by global, no-flow ischemia (30 min) and reperfusion (30 min) in the presence ( n = 10) or absence ( n = 14) of losartan (1 μmol/l) or the cardioprotective adenosine A1receptor agonist N 6-cyclohexyladenosine (CHA, 0.5 μmol/l, n = 11). During reperfusion in untreated hearts (controls), left ventricular (LV) minute work partially recovered to 38% of aerobic baseline, whereas proton production increased to 155%. Compared with controls, CHA improved recovery of LV work to 79% and reduced proton production to 44%. Losartan depressed recovery of LV work to 0% without altering proton production. However, exogenous ANG II (1–100 nmol/l) in combination with losartan restored recovery of LV work during reperfusion in a concentration-dependent manner, suggesting that postischemic recovery of function depends on intrinsic AT1-R stimulation.

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Naproxen-induced Ca2+ movement and death in MDCK canine renal tubular cells

Human & Experimental Toxicology ◽

10.1177/0960327115569810 ◽

2015 ◽

Vol 34 (11) ◽

pp. 1096-1105

Author(s):

H-H Cheng ◽

C-T Chou ◽

T-K Sun ◽

W-Z Liang ◽

J-S Cheng ◽

...

Keyword(s):

Endoplasmic Reticulum ◽

Annexin V ◽

Dependent Manner ◽

Acetoxymethyl Ester ◽

Concentration Dependent Manner ◽

Tubular Cells ◽

Renal Tubular Cells ◽

Renal Tubular ◽

Induced Apoptosis ◽

Darby Canine Kidney

Naproxen is an anti-inflammatory drug that affects cellular calcium ion (Ca2+) homeostasis and viability in different cells. This study explored the effect of naproxen on [Ca2+]i and viability in Madin-Darby canine kidney cells (MDCK) canine renal tubular cells. At concentrations between 50 μM and 300 μM, naproxen induced [Ca2+]i rises in a concentration-dependent manner. This Ca2+ signal was reduced partly when extracellular Ca2+ was removed. The Ca2+ signal was inhibited by a Ca2+ channel blocker nifedipine but not by store-operated Ca2+ channel inhibitors (econazole and SKF96365), a protein kinase C (PKC) activator phorbol 12-myristate 13-acetate, and a PKC inhibitor GF109203X. In Ca2+-free medium, pretreatment with 2,5-di-tert-butylhydroquinone or thapsigargin, an inhibitor of endoplasmic reticulum Ca2+ pumps, partly inhibited naproxen-induced Ca2+ signal. Inhibition of phospholipase C with U73122 did not alter naproxen-evoked [Ca2+]i rises. At concentrations between 15 μM and 30 μM, naproxen killed cells in a concentration-dependent manner, which was not reversed by prechelating cytosolic Ca2+ with the acetoxymethyl ester of 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetic acid acetoxymethyl. Annexin V/propidium iodide staining data suggest that naproxen induced apoptosis. Together, in MDCK renal tubular cells, naproxen induced [Ca2+]i rises by inducing Ca2+ release from multiple stores that included the endoplasmic reticulum and Ca2+ entry via nifedipine-sensitive Ca2+ channels. Naproxen induced cell death that involved apoptosis.

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Angiotensin II and its receptors in human endocardial endothelial cells: role in modulating intracellular calcium

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y03-046 ◽

2003 ◽

Vol 81 (3) ◽

pp. 259-266 ◽

Cited By ~ 22

Author(s):

Danielle Jacques ◽

Nelly A. Abdel Malak ◽

Sawsan Sader ◽

Claudine Perreault

Keyword(s):

Endothelial Cells ◽

Angiotensin Ii ◽

Confocal Microscopy ◽

Intracellular Calcium ◽

Fluorescence Signal ◽

Ang Ii ◽

Microscopy Technique ◽

Endocardial Endothelial Cells ◽

Microscopy Techniques ◽

Dose Dependent

he aims of the present study are to investigate the presence and distribution of angiotensin II (Ang II), as well as AT1 and AT2 receptors, in endocardial endothelial cells (EECs) and to determine if the effect of Ang II on intracellular calcium in these cells is mediated via the AT1 or the AT2 receptor. Immunofluorescence and 3D confocal microscopy techniques were used on 20-week-old fetal human EECs. Our results showed that Ang II and its receptors, the AT1 and the AT2 types, are present and exhibit a different distribution in human EECs. Ang II labelling is found throughout the cell with a fluorescence signal higher in the cytosol when compared with the nucleus. Like Ang II, the AT1 receptor fluorescence signal is also homogeneously distributed in human EECs but with a preferential labelling at the level of the nucleus, while the AT2 receptor labelling is solely present in the nucleus. Using fluo-3 and 3D confocal microscopy technique, superfusion of human EECs with increasing concentration of Ang II induced a dose-dependent sustained increase in free cytosolic and nuclear Ca2+ levels. This effect of Ang II on human EEC's intra cellular Ca2+ ([Ca2+]i) was completely prevented by losartan, an AT1 receptor antagonist. Our results suggest that Ang II, as well as AT1 and AT2 receptors, is present but differentially distributed in EECs of 20-week-old fetal human hearts, and that the AT1 receptor mediates the effects of Ang II on [Ca2+]i in these cells.Key words: angiotensin II, nuclear receptors, endocardial endothelial cells, Ang II receptors, intracellular calcium.

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The Study on Angiotensin II Induced-Ferroptosis in Vascular Endothelial Cells

10.21203/rs.3.rs-565583/v1 ◽

2021 ◽

Author(s):

hong fang ◽

Chi liu ◽

Omer Cavdar ◽

Yi Shen

Keyword(s):

Endothelial Cells ◽

Angiotensin Ii ◽

Molecular Marker ◽

Analysis Of Variance ◽

Vascular Endothelial Cells ◽

Dependent Manner ◽

Vascular Endothelial ◽

Ang Ii ◽

Valsartan Group ◽

Dose Dependent

Abstract PurposeTo verify the effect of Angiotensin II on ferroptosis in vascular endothelial cells and clarify the related mechanism. MethodsHUVECs were evaluated for p53, P21,ALOX12, VEGF, MDA,GSH. Molecular marker impact upon AngII-induced ferroptosis was evaluated with students’ t-test，one-way analysis of variance (ANOVA).ResultsAs the concentration of Ang II increased，the level of ALOX12, P53,GSH and MDA increased in HUVECs. The expression of VEGFA in HUVECs is negatively correlated with dose of Ang II. Incubation of HUVECs in AngII and valsartan for 48hr reduces ALOX12, P21, GSH and MDA. Compared with the single AngII group, ALOX12, P21, GSH and MDA in valsartan group was decreased significantly（p=0.000）.In pifithrin-α hydrobromide-treated, ALOX12, P21, GSH and MDA was reduced significantly, as compared to valsartan group（p=0.000）. The most larger reduction in ALOX12, P21,GSH and MDA was pifithrin - α hydrobromide combined with valsartan group. In contrast, the expression of VEGFA increased significantly after HUVECs were treated with pifithrin - α hydrobromide and valsartan（p=0.000）.ConclusionsAngII can induce ferroptosis of vascular endothelial cells in a dose-dependent manner. The mechanism of AngII-induced ferroptosis may be regulated through the signal axis of ATR1,2-p53-ALOX12.

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Abstract P127: Angiotensin II Priming Enhances Prostaglandin E2 Vasoconstrictor Effects

Hypertension ◽

10.1161/hyp.66.suppl_1.p127 ◽

2015 ◽

Vol 66 (suppl_1) ◽

Author(s):

Maria P Kraemer ◽

Fred Lamb ◽

Richard M Breyer

Keyword(s):

Blood Pressure ◽

Angiotensin Ii ◽

Kinase Inhibitor ◽

Rho Kinase ◽

Area Under The Curve ◽

Prostaglandin E ◽

Dependent Manner ◽

Ang Ii ◽

Concentration Dependent Manner ◽

Femoral Arteries

Prostaglandins are key modulators of blood pressure and arterial tone. Prostaglandin E 2 (PGE 2 ), is a prostanoid that has vasodepressor effects; however, under certain circumstances PGE 2 can induce vasopressor responses. Recent reports demonstrated that sub-threshold concentrations of vasoconstrictors augment PGE 2 -mediated constriction in rat femoral arteries. However, whether angiotensin II (Ang II) could affect PGE 2 -mediated contraction is not known. Using a wire myograph, we demonstrated that PGE 2 had no significant effect on mouse femoral arterial rings at doses up to 1 μM. However, priming of arterial rings with 1 nM Ang II potentiated PGE 2 -evoked constriction in a concentration dependent manner (Area Under the Curve, AUC untreated 1.784 ± 0.353, AUC Ang II 23.27± 9.820, P<0.05). We tested femoral arteries from EP1, EP2, and EP3 receptor knockout mice. Only the EP3-/- arteries were unable to respond to PGE 2 after Ang II priming (figure below). Pretreatment of arterial rings with 1 μM losartan, an angiotensin receptor antagonist, blocked PGE 2 -induced constrictor effects primed with Ang II (% of KCl, Ang II 21.72 ± 5.296, Ang II + losartan 3.025 ± 1.046, n=3). We have determined that re-addition of extracellular Ca 2+ to a Ca 2+ -free artery restores PGE 2 -induced contractions (n=5) and that the Rho-kinase inhibitor Y-27632 blocks contraction (n=3). Taken together these data are consistent with angiotensin AT1 and prostaglandin EP3 receptors mediating a synergistic Rho-kinase-dependent contractile response. We are continuing to investigate the relationship between Ang II and PGE 2 to determine the physiological relevance this may have in modulating blood pressure.

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EDRF-angiotensin II interactions in rat juxtamedullary afferent and efferent arterioles

AJP Renal Physiology ◽

10.1152/ajprenal.1992.263.5.f900 ◽

1992 ◽

Vol 263 (5) ◽

pp. F900-F906 ◽

Cited By ~ 28

Author(s):

K. Ohishi ◽

P. K. Carmines ◽

E. W. Inscho ◽

L. G. Navar

Keyword(s):

Angiotensin Ii ◽

Renin Angiotensin System ◽

Biological Action ◽

Dependent Manner ◽

Ang Ii ◽

Synthesis Inhibitor ◽

Concentration Dependent Manner ◽

Arteriolar Resistance ◽

Constrictor Response

The in vitro blood-perfused juxtamedullary nephron technique was utilized to determine the contribution of endothelium-derived relaxing factor (EDRF) to resting renal arteriolar caliber and to evaluate the interaction between EDRF and angiotensin II (ANG II) in renal microvascular control. Video microscopy was employed to visualize rat afferent and efferent arterioles and to measure their responses to blockade of nitric oxide (NO), which has been shown to account for much of the biological action of EDRF. The NO synthesis inhibitor, N omega-nitro-L-arginine (L-NNA), elicited vasoconstriction in a concentration-dependent manner, with 1,000 microM L-NNA significantly reducing both afferent (16 +/- 3%) and efferent (13 +/- 1%) diameters. This concentration of L-NNA also blocked the vasodilator response to 10 microM acetylcholine, while responsiveness to sodium nitroprusside was maintained. Vasoconstrictor responses to 1,000 microM L-NNA were attenuated in kidneys from rats pretreated with enalaprilat or losartan, reducing afferent diameter by 7 +/- 1 (n = 8) and 3 +/- 1% (n = 10) of control, respectively. Efferent arteriolar responses to L-NNA were similarly attenuated by losartan. The constrictor response to 10 nM ANG II was not exaggerated by L-NNA, suggesting that ANG II does not stimulate EDRF synthesis. These observations indicate that EDRF is continuously released in a quantity sufficient to affect both afferent and efferent arterioles of juxtamedullary nephrons in vitro. Furthermore, ANG II blockade attenuates the vasoconstriction elicited by L-NNA, suggesting that EDRF interacts with the renin-angiotensin system to control juxtamedullary afferent and efferent arteriolar resistance.

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Angiotensin II modulates mouse skeletal muscle resting conductance to chloride and potassium ions and calcium homeostasis via the AT1 receptor and NADPH oxidase

AJP Cell Physiology ◽

10.1152/ajpcell.00372.2013 ◽

2014 ◽

Vol 307 (7) ◽

pp. C634-C647 ◽

Cited By ~ 19

Author(s):

Anna Cozzoli ◽

Antonella Liantonio ◽

Elena Conte ◽

Maria Cannone ◽

Ada Maria Massari ◽

...

Keyword(s):

Angiotensin Ii ◽

Nadph Oxidase ◽

Calcium Homeostasis ◽

Potassium Conductance ◽

Mdx Mouse ◽

Dependent Manner ◽

Ang Ii ◽

Concentration Dependent Manner

Angiotensin II (ANG II) plays a role in muscle wasting and remodeling; however, little evidence shows its direct effects on specific muscle functions. We presently investigated the acute in vitro effects of ANG II on resting ionic conductance and calcium homeostasis of mouse extensor digitorum longus (EDL) muscle fibers, based on previous findings that in vivo inhibition of ANG II counteracts the impairment of macroscopic ClC-1 chloride channel conductance (gCl) in the mdx mouse model of muscular dystrophy. By means of intracellular microelectrode recordings we found that ANG II reduced gCl in the nanomolar range and in a concentration-dependent manner (EC50 = 0.06 μM) meanwhile increasing potassium conductance (gK). Both effects were inhibited by the ANG II receptors type 1 (AT1)-receptor antagonist losartan and the protein kinase C inhibitor chelerythrine; no antagonism was observed with the AT2 antagonist PD123,319. The scavenger of reactive oxygen species (ROS) N-acetyl cysteine and the NADPH-oxidase (NOX) inhibitor apocynin also antagonized ANG II effects on resting ionic conductances; the ANG II-dependent gK increase was blocked by iberiotoxin, an inhibitor of calcium-activated potassium channels. ANG II also lowered the threshold for myofiber and muscle contraction. Both ANG II and the AT1 agonist L162,313 increased the intracellular calcium transients, measured by fura-2, with a two-step pattern. These latter effects were not observed in the presence of losartan and of the phospholipase C inhibitor U73122 and the in absence of extracellular calcium, disclosing a Gq-mediated calcium entry mechanism. The data show for the first time that the AT1-mediated ANG II pathway, also involving NOX and ROS, directly modulates ion channels and calcium homeostasis in adult myofibers.

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