Functional role, cellular source, and tissue distribution of rat elastase-2, an angiotensin II-forming enzyme

2003 ◽  
Vol 285 (2) ◽  
pp. H775-H783 ◽  
Author(s):  
Carlos F. Santos ◽  
Marcos Antonio V. Caprio ◽  
Eduardo B. Oliveira ◽  
Maria Cristina O. Salgado ◽  
Daniela N. Schippers ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Alternative Pathway ◽  
Physiological Role ◽  
Rat Tissues ◽  
Ang Ii ◽  
Renin Substrate ◽  
Mesenteric Arterial Bed ◽  
Cellular Source ◽  
Rat Elastase ◽  
Kidney Liver

We recently described a chymostatin-sensitive elastase-2 as the major angiotensin (ANG) II-forming enzyme in the perfusate of the rat mesenteric arterial bed (MAB) with the same cDNA sequence as rat pancreatic elastase-2. The role of this enzyme in generating ANG II was examined in the rat isolated and perfused MAB. The vasoconstrictor effect elicited by ANG I and the renin substrate tetradecapeptide was only partially inhibited by captopril but abolished by the combination of captopril and chymostatin or N-acetyl-Ala-Ala-Pro-Leu-chloromethylketone (Ac-AAPL-CK; inhibitor originally developed for human elastase-2). The effect induced by [Pro11,d-Ala12]-ANG I, an ANG I-converting enzyme (ACE)-resistant biologically inactive precursor of ANG II, was blocked by chymostatin or Ac-AAPL-CK. It was also demonstrated that cultured rat mesenteric endothelial cells synthesize elastase-2 and that mRNA for this enzyme can be detected in different rat tissues such as the pancreas, MAB, lung, heart, kidney, liver, and spleen. In conclusion, the demonstration of a functional alternative pathway to ACE for ANG II generation in the rat MAB and the fact that cultured MAB endothelial cells are capable of producing and secreting elastase-2 represent strong evidence of a physiological role for this enzyme in the rat vasculature.

scholarly journals A study of the localization of polynucleotide phosphorylase within rat liver cells and of its distribution among rat tissues and diverse animal species

1972 ◽  
Vol 130 (2) ◽  
pp. 355-362 ◽  
Author(s):  
Y P See ◽  
P. S. Fitt
Keyword(s):  
Guinea Pig ◽  
Rat Liver ◽  
Rat Heart ◽  
Animal Species ◽  
Physiological Role ◽  
Rat Tissues ◽  
Mitochondrial Enzyme ◽  
Polynucleotide Phosphorylase ◽  
Rat Liver Cells ◽  
Kidney Liver

1. Rat liver polynucleotide phosphorylase was localized in the mitochondrion, but may also occur in the nucleus. 2. The mitochondrial enzyme was found in rat heart, kidney, liver, muscle and spleen. 3. Mitochondrial polynucleotide phosphorylase is also present in calf, chicken, guinea-pig and rabbit liver and in goldfish muscle. 4. A possible physiological role for the enzyme in the control of the intramitochondrial ADP concentration is suggested.

Conversion of renin substrate tetradecapeptide to angiotensin II by rat MAB elastase-2

2004 ◽  
Vol 82 (11) ◽  
pp. 1000-1005 ◽  
Author(s):  
Carlos F Santos ◽  
Andrew S Greene ◽  
Maria Cristina O Salgado ◽  
Eduardo B Oliveira
Keyword(s):  
Angiotensin Ii ◽  
Enzymatic Activity ◽  
Catalytic Efficiency ◽  
Inhibitory Effect ◽  
Ang Ii ◽  
Chromogenic Substrates ◽  
Renin Substrate ◽  
New Approach ◽  
Pancreatic Elastase ◽  
Mesenteric Arterial Bed

A new approach for the purification of rat mesenteric arterial bed (MAB) elastase-2 has been developed using the chromogenic substrates N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide and N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide to monitor the enzymatic activity during various stages of purification. The purified enzyme was evaluated in the presence of various inhibitors and confirmed to have angiotensin (Ang) II-forming ability. The active site-directed inhibitor acetyl-Ala-Ala-Pro-Leu-chloromethylketone (100 µmol·L-1), described for human pancreatic elastase-2, abolished the enzymatic activity, confirming that the enzyme is an elastase-2. Chymostatin (100 µmol·L-1), an inhibitor regarded as selective for chymases, also showed a remarkable inhibitory effect (94%), whereas captopril (100 µmol·L-1) had no effect at all on the Ang II-forming activity. The Ang II precursor renin substrate tetradecapeptide (RS-14P) was converted into Ang II by the rat MAB elastase-2 with the following kinetic constants: Km = 124 ± 21 µmol·L-1; Kcat = 629 min-1; catalytic efficiency (Kcat /Km) = 5.1 min-1 µ(mol/L)-1. In conclusion, the strategy for the purification of rat MAB elastase-2 with the chromogenic substrates proved to be simple, rapid, accurate, and highly reproducible; therefore, it can be reliably and conveniently used to routinely purify this enzyme. The kinetic parameters for the formation of Ang II from RS-14P by rat MAB elastase-2 emphasize differences in substrate specificity between this and other Ang II-forming enzymes.Key words: N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide, elastase-2, angiotensin II, renin substrate tetradecapeptide.

Natriuretic Peptides Regulate the Expression of Tissue Factor and PAI-1 in Endothelial Cells

1999 ◽  
Vol 82 (11) ◽  
pp. 1497-1503 ◽  
Author(s):  
Hajime Tsuji ◽  
Hiromi Nishimura ◽  
Haruchika Masuda ◽  
Yasushi Kunieda ◽  
Hidehiko Kawano ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Plasminogen Activator ◽  
Natriuretic Peptide ◽  
Culture Media ◽  
Tissue Type ◽  
Dependent Manner ◽  
Ang Ii ◽  
Plasminogen Activator Inhibitor 1 ◽  
Pai 1

SummaryIn the present study, we demonstrate that brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) interact with angiotensin II (Ang II) in regulative blood coagulation and fibrinolysis by suppressing the expressions of both tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) induced by Ang II. The expressions of TF and PAI-1 mRNA were analyzed by northern blotting methods, and the activities of TF on the surface of rat aortic endothelial cells (RAECs) and PAI-1 in the culture media were respectively measured by chromogenic assay.Both BNP and CNP suppressed the expressions of TF and PAI-1 mRNA induced by Ang II in a time- and concentration-dependent manner via cGMP cascade, which suppressions were accompanied by respective decrease in activities of TF and PAI-1. However, neither the expression of tissue factor pathway inhibitor (TFPI) nor tissue-type plasminogen activator (TPA) mRNA was affected by the treatment of BNP and CNP.

Expression of human endothelin-converting enzyme isoforms: role of angiotensin IIThis article is one of a selection of papers published in the special issue (part 1 of 2) on Forefronts in Endothelin.

2008 ◽  
Vol 86 (6) ◽  
pp. 299-309 ◽  
Author(s):  
W. Goettsch ◽  
A. Schubert ◽  
H. Morawietz
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Umbilical Vein ◽  
Artery Bypass ◽  
Control Group ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Mammary Arteries ◽  
Endothelin Converting Enzyme ◽  
Internal Mammary

A key step in endothelin-1 (ET-1) synthesis is the proteolytic cleavage of big ET-1 by the endothelin-converting enzyme-1 (ECE-1). Four alternatively spliced isoforms, ECE-1a to ECE-1d, have been discovered; however, regulation of the expression of specific ECE-1 isoforms is not well understood. Therefore, we stimulated primary human umbilical vein endothelial cells (HUVECs) with angiotensin II (Ang II). Furthermore, expression of ECE-1 isoforms was determined in internal mammary arteries of patients undergoing coronary artery bypass grafting surgery. Patients had received one of 4 therapies: angiotensin-converting enzyme inhibitors (ACE-I), Ang II type 1 receptor blockers (ARB), HMG-CoA reductase inhibitors (statins), and a control group that had received neither ACE-I, ARB (that is, treatment not interfering in the renin–angiotensin system), nor statins. Under control conditions, ECE-1a is the dominant isoform in HUVECs (4.5 ± 2.8 amol/μg RNA), followed by ECE-1c (2.7 ± 1.0 amol/μg), ECE-1d (0.49 ± 0.17 amol/μg), and ECE-1b (0.17 ± 0.04 amol/μg). Stimulation with Ang II did not change the ECE-1 expression pattern or the ET-1 release. We found that ECE-1 mRNA expression was higher in patients treated with statins than in patients treated with ARB therapy (5.8 ± 0.76 RU versus 3.0 ± 0.4 RU), mainly attributed to ECE-1a. In addition, ECE-1a mRNA expression was higher in patients receiving ACE-I therapy than in patients receiving ARB therapy (1.68 ± 0.27 RU versus 0.83 ± 0.07 RU). We conclude that ECE-1a is the major ECE-1 isoform in primary human endothelial cells. Its expression in internal mammary arteries can be regulated by statin therapy and differs between patients with ACE-I and ARB therapy.

Uptake, distribution, and excretion of 31silicon in normal rats

1986 ◽  
Vol 251 (6) ◽  
pp. E670-E673 ◽  
Author(s):  
A. J. Adler ◽  
Z. Etzion ◽  
G. M. Berlyne
Keyword(s):  
Blood Brain Barrier ◽  
Silicic Acid ◽  
Plasma Levels ◽  
Brain Barrier ◽  
Major Portion ◽  
Rat Tissues ◽  
Blood Brain ◽  
Intracardiac Injection ◽  
Wet Weight ◽  
Kidney Liver

This study examines the uptake, distribution, and excretion of 31-labeled silicic acid in rat tissues at 1, 2, and 4 h after intracardiac injection of 31Si(OH)4. Plasma levels of 31Si decrease rapidly from 0.71 +/- 0.04% at 1 h to 0.07 +/- 0.06% of the dose administered per milliliter at 4 h. 31Si in plasma was found to be virtually entirely nonprotein bound. Kidney, liver, and lung accumulated the greatest amounts of 31Si per gram of wet weight, with concentrations at 4 h suggesting both relatively avid uptake and retention. Bone, skin, spleen, muscle, and testes also accumulated 31Si, but the levels were considerably lower than the aforementioned organs. Brain, however, contained negligible concentrations of 31Si throughout the study, indicating active exclusion by the blood-brain barrier. The major portion of the administered 31Si, 77 +/- 12%, was recovered in the urine within 4 h.

Free heme transforms endothelial cells into alternative pathway activators. Implications for the hemolytic and uremic syndrome

Immunobiology ◽  
2012 ◽  
Vol 217 (11) ◽  
pp. 1172
Author(s):  
Marie Frimat ◽  
Fanny Tabarin ◽  
Lise Halbwachs ◽  
Caroline Poitou ◽  
Jordan Dimitrov ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Alternative Pathway ◽  
Free Heme ◽  
Uremic Syndrome

Abstract WMP78: The Efficacy of Angiotensin II Peptide Vaccination Against White Matter Lesions of Vascular Dementia in Rats

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Kouji Wakayama ◽  
Munehisa Shimamura ◽  
Hironori Nakagami ◽  
Ryuichi Morishita
Keyword(s):  
Endothelial Cells ◽  
Cognitive Function ◽  
Angiotensin Ii ◽  
White Matter ◽  
Western Blot ◽  
Vascular Dementia ◽  
White Matter Lesions ◽  
Ang Ii ◽  
Peptide Vaccination ◽  
Brdu Assay

Background & Purposes: There had been no attempt to show the efficacy of therapeutic vaccination in vascular dementia. A rat model of vascular dementia was prepared by bilateral common carotid artery ligation (2VO). The purpose of this study is to investigate whether pre-exposure Angiotensin II (Ang II) peptide vaccination exhibits the protective effects against white matter lesions (WML) in 2VO rats. Methods: After subcutaneous injection of Ang II peptide vaccine (10μg/200μl) or saline (200μl) to Wistar rats (male) at the time point of 6, 8 and 10 week-old, 2VO or sham surgery was performed at 12 week-old. Cognitive function was evaluated after 14 days of 2VO using the novel object recognition (NOR) test. Anti-Ang II antibody (Ab) level was quantified using ELISA. Histological examinations of WML and demyelination in the corpus callosum (CC) were evaluated using immunohistochemistry (IHC), 5-bromodeoxyuridine (BrdU) assay and Klüver-Barrera staining. Western blot analyses of VCAM-1, FGF2, phospho-CREB and CREB using proteins extracted from CC were performed to investigate the mechanism of restoration of WML by Ang II vaccination. Results: Histological examinations presented that exacerbation of WML and demyelination observed in saline treated (S) rats was ameliorated in Ang II vaccinated (V) rats. The results of NOR test indicated that cognitive dysfunction observed in S rats was improved in V rats at 14 days after 2VO. Expression of VCAM-1 in CC of S rats was significantly reduced in V rats at 7 days after 2VO. BrdU assay exhibited that vaccination accelerated the differentiation of oligodendrocyte progenitor cells (OPCs) in WML from 14 days to 28 days of 2VO. Western blot presented that both CREB phosphorylation and FGF2 expression in CC were increased in V rats compared with S rats at 14 days after 2VO. Double IHC showed that FGF2 expressing cells were mostly endothelial cells and astrocytes in WML. Conclusions: Ang II vaccination restored WML as well as cognitive function in 2VO rats. Our findings suggested that Ang II vaccination ameliorated cerebrovascular endothelial dysfunction which could accelerate the OPCs differentiation through increased expression of FGF2 in endothelial cells or astrocytes in 2VO rats.

Abstract 261: Endothelial Cells Contribute to RAS Activation in Microvascular Smooth Muscle Cells

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Kayoko Miyata ◽  
Ryousuke Satou ◽  
L Gabriel Navar
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Mrna Expression ◽  
Culture Medium ◽  
Primary Cultures ◽  
Mrna Levels ◽  
Ang Ii ◽  
Relative Ratio ◽  
Renin Mrna ◽  
Afferent Arterioles

Introduction: We have demonstrated that Ang II augments angiotensinogen (AGT) expression in rat preglomerular vascular smooth muscle cells (VSMCs). However, it is unclear if endothelial cells (ECs) are involved in augmentation of AGT in renal afferent arterioles. Hypothesis: We assessed the hypothesis that the ECs respond to paracrine signals that Ang II contribute to AGT augmentation in VSMCs. Objective: We established primary cultures of preglomerular ECs and examined the effects of Ang II and/or culture medium from ECs on AGT expression in preglomerular VSMCs. Methods and Results: We established primary cultures of preglomerular ECs, isolated from afferent arterioles of Sprague-Dawley rats. The cells were identified as ECs by being positive for a marker, CD34 and endothelial NOS and negative for alpha-SMA (a marker for VSMCs) and P4H-b (a marker for Fibroblasts) by immnostaining. The expression levels of AGT mRNA and renin mRNA in preglomerular ECs were examined by real-time RT-PCR. Ang II (100 pmol/L) increased AGT mRNA levels (1.34 +/- 0.16, by 100 pmol/L, N=4) and Renin mRNA levels (6.16 +/- 0.96, by 100 nmol/L, N=4) in ECs. On the other hand, the same dose of Ang II suppressed Renin mRNA expression in isolated Juxtaglomerular cells (JGs). These results indicate that preglomerular ECs are respond to Ang II and exclude the possible contamination of JGs into ECs. 100 pmol/L of Ang II increased AGT mRNA expression levels (1.37 +/- 0.03, relative ratio, N=4) in preglomerular VSMCs and the culture medium of ECs without Ang II treatment also more increased AGT mRNA expression (1.62 +/- 0.13, relative ratio, N=4) in preglomerular VSMCs. The AGT mRNA expression augmentation was enhanced when preglomerular VSMCs were treated with culture medium of Ang II-treated preglomerular ECs (2.39 +/- 0.41, relative ratio, N=4). The synergistic effects of Ang II and preglomerular ECs were also observed in PAI-1 expression in preglomerular VSMCs. Conclusion: These data demonstrate that preglomerular ECs contribute to Ang II-upregulation of AGT in renal afferent arterioles leading to further Ang II augmentation, which leads to increases in inflammatory and sclerotic factors in preglomerular VSMCs.

scholarly journals Alpha-Asarone Protects Endothelial Cells from Injury by Angiotensin II

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hai-Xia Shi ◽  
Jiajun Yang ◽  
Tao Yang ◽  
Yong-Liang Xue ◽  
Jun Liu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Angiotensin Ii ◽  
Cell Injury ◽  
Fluorescent Dyes ◽  
Umbilical Vein ◽  
Protective Effects ◽  
Ang Ii ◽  
Versus Model

α-Asarone is the major therapeutical constituent ofAcorus tatarinowiiSchott. In this study, the potential protective effects ofα-asarone against endothelial cell injury induced by angiotensin II were investigatedin vitro. The EA.hy926 cell line derived from human umbilical vein endothelial cells was pretreated withα-asarone (10, 50, 100 µmol/L) for 1 h, followed by coincubation with Ang II (0.1 µmol/L) for 24 h. Intracellular nitric oxide (NO) and reactive oxygen species (ROS) were detected by fluorescent dyes, and phosphorylation of endothelial nitric oxide synthase (eNOS) atSer1177was determined by Western blotting.α-Asarone dose-dependently mitigated the Ang II-induced intracellular NO reduction (P<0.01versus model) and ROS production (P<0.01versus model). Furthermore, eNOS phosphorylation (Ser1177) by acetylcholine was significantly inhibited by Ang II, while pretreatment for 1 h withα-asarone partially prevented this effect (P<0.05versus model). Additionally, cell viability determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (105~114.5% versus control,P>0.05) was not affected after 24 h of incubation withα-asarone at 1–100 µmol/L. Therefore,α-asarone protects against Ang II-mediated damage of endothelial cells and may be developed to prevent injury to cardiovascular tissues.

scholarly journals The Hinge-Helix 1 Region of Peroxisome Proliferator-Activated Receptor γ1 (PPARγ1) Mediates Interaction with Extracellular Signal-Regulated Kinase 5 and PPARγ1 Transcriptional Activation: Involvement in Flow-Induced PPARγ Activation in Endothelial Cells

2004 ◽  
Vol 24 (19) ◽  
pp. 8691-8704 ◽  
Author(s):  
Masashi Akaike ◽  
Wenyi Che ◽  
Nicole-Lerner Marmarosh ◽  
Shinsuke Ohta ◽  
Masaki Osawa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Adhesion Molecule ◽  
Critical Role ◽  
Physiological Role ◽  
Cellular Adhesion ◽  
Dominant Negative ◽  
Peroxisome Proliferator ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Cellular Adhesion Molecule

ABSTRACT Peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors that form a subfamily of the nuclear receptor gene family. Since both flow and PPARγ have atheroprotective effects and extracellular signal-regulated kinase 5 (ERK5) kinase activity is significantly increased by flow, we investigated whether ERK5 kinase regulates PPARγ activity. We found that activation of ERK5 induced PPARγ1 activation in endothelial cells (ECs). However, we could not detect PPARγ phosphorylation by incubation with activated ERK5 in vitro, in contrast to ERK1/2 and JNK, suggesting a role for ERK5 as a scaffold. Endogenous PPARγ1 was coimmunoprecipitated with endogenous ERK5 in ECs. By mammalian two-hybrid analysis, we found that PPARγ1 associated with ERK5a at the hinge-helix 1 region of PPARγ1. Expressing a hinge-helix 1 region PPARγ1 fragment disrupted the ERK5a-PPARγ1 interaction, suggesting a critical role for hinge-helix 1 region of PPARγ in the ERK5-PPARγ interaction. Flow increased ERK5 and PPARγ1 activation, and the hinge-helix 1 region of the PPARγ1 fragment and dominant negative MEK5β significantly reduced flow-induced PPARγ activation. The dominant negative MEK5β also prevented flow-mediated inhibition of tumor necrosis factor alpha-mediated NF-κB activation and adhesion molecule expression, including vascular cellular adhesion molecule 1 and E-selectin, indicating a physiological role for ERK5 and PPARγ activation in flow-mediated antiinflammatory effects. We also found that ERK5 kinase activation was required, likely by inducing a conformational change in the NH2-terminal region of ERK5 that prevented association of ERK5 and PPARγ1. Furthermore, association of ERK5a and PPARγ1 disrupted the interaction of SMRT and PPARγ1, thereby inducing PPARγ activation. These data suggest that ERK5 mediates flow- and ligand-induced PPARγ activation via the interaction of ERK5 with the hinge-helix 1 region of PPARγ.

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