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Expression of functional angiotensin-converting enzyme and AT1 receptors in cultured human cardiac fibroblasts

Hafizi, Sassan LU ; Wharton, J; Morgan, K; Allen, S P; Chester, A H; Catravas, J D; Polak, J M and Yacoub, M H (1998) In Circulation 98(23). p.2553-2559
Abstract
BACKGROUND: Angiotensin II (Ang II) has been implicated in the development of cardiac fibrosis. The aims of the present study were to examine expression and activity of ACE and of angiotensin receptors in human cardiac fibroblasts cultured from dilated cardiomyopathic and ischemic hearts. The effects of Ang II on fibroblasts were also investigated. METHODS AND RESULTS: Human cardiac fibroblasts were cultured from ventricular and atrial myocardium and characterized immunohistochemically. Expression of ACE and the angiotensin AT1 receptor was demonstrated in cardiac fibroblasts by reverse transcriptase-polymerase chain reaction and radioligand binding. Functional ACE activity, measured by radiolabeled substrate conversion assay, was detected... (More)
BACKGROUND: Angiotensin II (Ang II) has been implicated in the development of cardiac fibrosis. The aims of the present study were to examine expression and activity of ACE and of angiotensin receptors in human cardiac fibroblasts cultured from dilated cardiomyopathic and ischemic hearts. The effects of Ang II on fibroblasts were also investigated. METHODS AND RESULTS: Human cardiac fibroblasts were cultured from ventricular and atrial myocardium and characterized immunohistochemically. Expression of ACE and the angiotensin AT1 receptor was demonstrated in cardiac fibroblasts by reverse transcriptase-polymerase chain reaction and radioligand binding. Functional ACE activity, measured by radiolabeled substrate conversion assay, was detected in both ventricular (Vmax. Km-1. mg-1, 0.031+/-0.010; n=13) and atrial (0. 034+/-0.012; n=6) fibroblasts. Fibroblast ACE activity was increased after 48 hours of treatment with basic fibroblast growth factor, dexamethasone, and phorbol ester. Ang II did not affect DNA synthesis but stimulated [3H]proline incorporation in cardiac fibroblasts (20.0+/-4.0% increase above control by 10 micromol/L; P<0.05, n=7), which was abolished by losartan 10 micromol/L but not PD123319 1 micromol/L. Ang II also stimulated a rise in intracellular calcium (basal, 56+/-1 nmol/L; Ang II, 355+/-24 nmol/L) via the AT1 receptor, as shown by complete inhibition with losartan. CONCLUSIONS: We have demonstrated expression and activity of ACE and AT1 receptor in cultured human cardiac fibroblasts. In addition, cardiac fibroblasts respond to Ang II with AT1 receptor-mediated collagen synthesis. The presence of local ACE and AT1 receptors in human fibroblasts suggests their involvement in the development of cardiac fibrosis. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
enzymes, angiotensin, receptors, collagen, cells
in
Circulation
volume
98
issue
23
pages
2553 - 2559
publisher
Lippincott Williams and Wilkins
external identifiers
  • pmid:9843462
  • scopus:0032497940
ISSN
1524-4539
language
English
LU publication?
no
id
cbc851d9-e744-4781-b75e-76a46464b825 (old id 1112904)
alternative location
http://circ.ahajournals.org/cgi/content/full/98/23/2553
date added to LUP
2008-07-11 14:06:32
date last changed
2017-01-01 07:26:50
@article{cbc851d9-e744-4781-b75e-76a46464b825,
  abstract     = {BACKGROUND: Angiotensin II (Ang II) has been implicated in the development of cardiac fibrosis. The aims of the present study were to examine expression and activity of ACE and of angiotensin receptors in human cardiac fibroblasts cultured from dilated cardiomyopathic and ischemic hearts. The effects of Ang II on fibroblasts were also investigated. METHODS AND RESULTS: Human cardiac fibroblasts were cultured from ventricular and atrial myocardium and characterized immunohistochemically. Expression of ACE and the angiotensin AT1 receptor was demonstrated in cardiac fibroblasts by reverse transcriptase-polymerase chain reaction and radioligand binding. Functional ACE activity, measured by radiolabeled substrate conversion assay, was detected in both ventricular (Vmax. Km-1. mg-1, 0.031+/-0.010; n=13) and atrial (0. 034+/-0.012; n=6) fibroblasts. Fibroblast ACE activity was increased after 48 hours of treatment with basic fibroblast growth factor, dexamethasone, and phorbol ester. Ang II did not affect DNA synthesis but stimulated [3H]proline incorporation in cardiac fibroblasts (20.0+/-4.0% increase above control by 10 micromol/L; P&lt;0.05, n=7), which was abolished by losartan 10 micromol/L but not PD123319 1 micromol/L. Ang II also stimulated a rise in intracellular calcium (basal, 56+/-1 nmol/L; Ang II, 355+/-24 nmol/L) via the AT1 receptor, as shown by complete inhibition with losartan. CONCLUSIONS: We have demonstrated expression and activity of ACE and AT1 receptor in cultured human cardiac fibroblasts. In addition, cardiac fibroblasts respond to Ang II with AT1 receptor-mediated collagen synthesis. The presence of local ACE and AT1 receptors in human fibroblasts suggests their involvement in the development of cardiac fibrosis.},
  author       = {Hafizi, Sassan and Wharton, J and Morgan, K and Allen, S P and Chester, A H and Catravas, J D and Polak, J M and Yacoub, M H},
  issn         = {1524-4539},
  keyword      = {enzymes,angiotensin,receptors,collagen,cells},
  language     = {eng},
  number       = {23},
  pages        = {2553--2559},
  publisher    = {Lippincott Williams and Wilkins},
  series       = {Circulation},
  title        = {Expression of functional angiotensin-converting enzyme and AT1 receptors in cultured human cardiac fibroblasts},
  volume       = {98},
  year         = {1998},
}