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Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27858
Submitted 27 December 2002 ; accepted in final form 2 May 2003
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ABSTRACT |
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 TOP ABSTRACT MATERIALS AND METHODSRESULTSDISCUSSIONDISCLOSURESREFERENCES |
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-smooth muscle actin. It is unclear whether
myoFbs generate ET peptides and consequentially regulate pathophysiological
functions de novo through expression of the ET-1 precursor (prepro-ET-1),
ET-converting enzyme-1 (ECE-1), a metalloprotease that is required to convert
Big ET-1 to ET-1 and ET receptors. To address these intriguing questions, we
used cultured myoFbs isolated from 4-wk-old MI scar tissue. In cultured cells,
we found: 1) expression of mRNA for ET precursor gene
(ppET1), ECE-1, and ETA and ETB receptors by
semiquantitative RT-PCR; 2) phosphoramidon-sensitive ECE-1 activity,
which converts Big ET-1 to biologically active peptide ET-1; 3)
expression of ETA and ETB receptors; 4)
elaboration of Big ET-1 and ET-1 peptides in myoFb culture media; and
5) upregulation of type I collagen gene expression and synthesis by
ET, which was blocked by bosentan (a nonselective ETA- and
ETB receptor blocker). These studies clearly indicated that myoFbs
express and generate ET-1 and receptor-mediated modulation of type I collagen
expression by ET-1. Locally generated ET-1 may contribute to tissue repair of
the infarcted heart in an autocrine/paracrine manner.
converting enzyme; receptors; type I collagen; bosentan; ppET1 gene
, RI). Often following myocardial infarction (MI), the
remodeling process (extracellular matrix deposition) stands as an obstacle to
normal physiological functioning of the heart. Studies have identified a
deleterious role for endothelin (ET) after MI
(7,
8,
16,
22). In a clinical study that
consisted of 142 cardiac patients, plasma ET levels 3 days post-MI were
strongly correlated to survival probability, with high ET levels being
associated with an unfavorable prognosis
(23). Additional correlations
between ET and negative survival probability after MI were observed in rats
with left coronary artery ligation, where blockade of ETA receptors
with BQ-123 significantly increased the survival rate of animals
(29). In vivo and in vitro studies in several organ systems and cell cultures using ET receptor antagonists strongly indicate a correlation between endogenous ET and fibrous tissue formation. In the liver, studies demonstrated that antagonism of ET after the establishment of fibrosing injury reduced hepatic stellate cell activation and matrix production, which suggests a role for ET in the development of fibrogenesis (26). Addition of ET-1 to cultured cells led to increased collagen synthesis of adult rat cardiac fibroblasts (10) and neonatal bone organ cultures (41).
It has been shown that treatment with bosentan, an ETA and ETB receptor blocker, attenuated deoxycorticosterone acetate-induced cardiac fibrosis in rats (11). Furthermore, treatment with TAK-044, a nonselective ETA and ETB receptor antagonist, significantly reduced rat heart infarct size, which suggests a role for ET in tissue repair following MI (16).
Although several studies support the concept that administration of ET antagonists mitigates ET-mediated adverse remodeling (27, 30), some reports demonstrate that antagonizing ET action may aggravate remodeling after MI (7). However, the time of treatment with these receptor antagonists and the choice of antagonist used have been shown to play important roles in alleviating the ET-induced adverse remodeling (19, 22, 29, 39). In rats, subsequent to MI, ET was elevated in plasma and heart interstitial fluid (3, 8). To determine areas of ET-1 production in the infarcted heart, Oie et al. (21) examined infarcted regions of rat heart with immunohistochemistry and found heavy immunostaining for ET-1 in the granulation tissue at the site of infarction. Fibroblasts and endothelial cells also displayed marked immunoreactivity, and interestingly, the time course of the immunoreactivity correlated with wound healing and was consistent with ET production by the wound-healing cells that produce the granulation tissue (21).
Myofibroblasts (myoFbs) are the predominant wound-healing fibroblast-like
cells and have morphological features of both smooth muscle cells and
fibroblasts. They express extracellular matrix and contractile proteins and
play major roles in matrix remodeling and wound contraction in diverse tissues
(9,
15,
37). The contribution of
myoFbs to tissue repair in the injured heart is of considerable interest.
Recently it was demonstrated that ET along with vascular endothelial growth
factor (VEGF) is a major player in angiogenic response and gastric ulcer
healing processes (1). Our
previous and recent studies on cardiac myoFbs demonstrated that these cells
express ANG II (12),
transforming growth factor (TGF)-
1
(4), and VEGF
(5), which play major roles in
tissue regeneration and angiogenesis
(4,
5,
12,
15). However, it is unclear
whether these cells also produce ET de novo. To study the local production of
ET at the site of MI during tissue regeneration and/or remodeling, we
isolated, cultured, and examined myoFbs from the site of MI for various
components involved in de novo generation of ET. These components are composed
of the ET precursor (prepro-ET-1) gene ppET1, Big ET-1, ET-converting
enzyme-1 (ECE-1, a metalloprotease that converts Big ET-1 to ET-1), and
stereospecific ETA and ETB receptors. Furthermore, we
also investigated the influence of ET on type I collagen expression in this
study.
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MATERIALS AND METHODS |
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TOPABSTRACTMATERIALS AND METHODSRESULTSDISCUSSIONDISCLOSURESREFERENCES |
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Protease inhibitors (leupeptin, aprotinin, pepstatin A, and PMSF) were
purchased from Sigma Chemical (St. Louis, MO). Phosphoramidon, bestatin, and
actinonin were obtained from Peptide International (Louisville, KY). The
125I-labeled ET-1 was purchased from DuPont-NEN (Boston, MA). Rat
ET-1 and Big ET-1 were purchased from Peninsula Laboratories (Belmont, CA).
Bosentan was a generous gift from Roche Pharmaceuticals. Enzymes and other
reagents required for RT-PCR were obtained from Promega Biotech (Madison, WI).
The 2-microglobulin (2-MG) oligonucleotide
primers were purchased from ClonTech (Palo Alto, CA), and other
oligonucleotide primers were synthesized in the DNA Core Facility at the
University of Missouri Health Sciences Center (Columbia, MO). Rat-specific
anti-ETA and anti-ETB receptor antibodies were obtained
from Alomone Laboratories (Jerusalem, Israel). All other chemicals used in
this study were of reagent grade.
Isolation and Culture of MyoFbs
Left ventricular MI was created in 8-wk-old male Sprague-Dawley rats (250–300 g body wt) via ligation of the left coronary artery. Rats were euthanized 28 days following ligation, hearts were removed, and scar tissue from the infarcted area was isolated for harvesting the myoFbs. Rat MI models were created using a protocol approved by the Institutional Animal Care and Use Committee. Previous in vivo studies confirmed the presence of an abundant population of myoFbs at the site of infarction at 28 days post-MI (37). The border region was removed by microdissection to avoid possible contamination of blood vessels and cardiac myocytes from this region. Recovered MI scar tissue was washed four times with 5 ml of saline. Microdissected scar tissue was sliced into smaller pieces and placed in a six-well plate that contained 20% FCS in DMEM with amphotericin-B (2 µg/ml), gentamycin (20.5 µg/ml), and penicillin-streptomycin (20 U/ml and 20 µg/ml, respectively). After 6 h, additional medium with 10% FCS was added. Cells were washed after 24 h with DMEM that contained 10% FCS, and medium was subsequently replaced every 2–3 days. Cells were grown and maintained under the conditions previously described (4, 12). After 2 wk, cells reached confluence and were routinely split at a 1:3 ratio. Early passages of cells (passages 3 and 4) were frozen in 10% DMSO, stored in liquid nitrogen, and used as needed.
Morphological and phenotypical characterization of cultured myoFbs were
studied by immunohistochemical and confocal microscopy as previously reported
(4). Briefly, myoFbs were found
to be positive to -smooth muscle actin, vimentin, and desmin and
negative to anti-factor VIII. Vimentin staining is specific for
fibroblast-like cells and excludes the presence of vascular smooth muscle
cells from our preparations. Absence of a positive factor VIII result
indicated that these cells were nonendothelial. Therefore, cultured myoFbs
were neither endothelial nor vascular smooth muscle cells. We observed little
or no contamination of these cells in culture, and these cells were stable up
to 12 passages. We used cells from early passages for these studies to avoid
possible phenotypic instability.
RT-PCR Analysis
We used previously established semiquantitative RT-PCR assays
(5,
12) for prepro-ET-1, ECE-1,
and ETA and ETB receptor expression. To monitor cDNA
synthesis efficiency, 2-MG was used as an internal
control.
RNA extraction and cDNA synthesis. As reported previously (4, 12), total RNA was extracted from myoFbs using the guanidine thiocyanate/phenol method. Briefly, confluent myoFbs were washed with PBS, and total cellular RNA was extracted with RNAzol B solution (Biotecx; Houston, TX), which was followed by chloroform extraction and precipitation with isopropanol. RNA pellets were washed with 75% ethanol, air dried, and dissolved in distilled water. cDNA was synthesized by reverse transcription of cellular RNA as previously described (5).
Oligonucleotide primer design. PCR primers for amplifying rat
prepro-ET-1 (31), ECE-1
(43), and ETA
(18) and ETB
receptor cDNA were selected from the rat gene sequence as previously reported
(32). The
2-MG cDNA was PCR amplified using primers obtained from
ClonTech. The specificity of these primers was confirmed by purifying the
respective PCR products (QiaQuick gel extraction system, Qiagen; Chatsworth,
CA) and sequencing them. The sequences of the oligonucleotide primers used and
the expected PCR product sizes are summarized in
Table 1.
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Polymerase chain reaction. With the use of primer-specific
sequences of 2-MG, prepro-ET-1, ECE-1, and ETA and
ETB receptor genes were PCR amplified as described previously
(5,
12). Briefly, 25-µl PCR
reaction volumes that contained 20 mmol/l Tris·HCl (pH 8.3), 50 mmol/l
KCl, 1.5 mmol/l MgCl2, 0.01% (wt/vol) gelatin, 200 µmol/l of
each dNTP, 40 pmol of the appropriate oligonucleotide primers, 1 unit of
Taq DNA polymerase, and 5–10 µl of the diluted myoFb cDNAs
were amplified in a GeneAmp model 9600 thermocycler (Perkin-Elmer; Norwalk,
CT) using the following conditions: after an initial denaturation at 94°C
for 1 min, 2-MG sequences were PCR amplified using 25 cycles
of denaturation at 94°C for 15 s, annealing at 55°C for 1 min, and
primer extension at 72°C for 2 min with the denaturation time increasing
an additional 1 s/cycle. A final extension at 72°C for 5 min was performed
to ensure that all reactions were completed. Prepro-ET-1, ECE-1, and
ETA and ETB receptor sequences were PCR amplified using
a similar procedure except that the number of cycles was increased to 30 and
the annealing temperature was increased to 58°C. PCR products were
electrophoretically size fractionated on 1.5% agarose gels that contained
ethidium bromide and were visualized with UV light.
Separation and Determination of ET-1 in MyoFb Culture Media
Serum-free culture media (each dish contained 5–10 ml media/
2
million cells) from four separate experiments was utilized in triplicate, and
the medium was collected in the presence of protease inhibitor cocktail (final
concentrations were 1 µM each of pepstatin, aprotinin, leupeptin, bestatin,
actonin, and phosphoramidon, and 0.1 mM PMSF), separated on C-2 columns, and
concentrated before performance of ELISA for ET-1 or Big ET-1 (Amersham;
Arlington Heights, IL).
Preconditioned solid-phase C-2 extraction columns were equilibrated with Tris·HCl buffer (0.1 mol/l, pH 7.3), and the samples (5–10 ml/sample) were drawn through the cartridge by vacuum. ET peptides were eluted with 0.1% trifluoroacetic acid in acetonitrile, evaporated to dryness in a Speed Vac concentrator equipped with a cold-finger trap, dissolved in ELISA buffer, and then stored at –20°C until further analysis by ELISA. ET peptide extraction efficiency in myoFb culture media ranged from 70 to 83%, which suggests a possible 13–30% underestimation of these peptides.
Protein Analysis
MyoFb lysate protein content was determined using a modified Lowry method (Bio-Rad protein assay kit, Bio-Rad Laboratories; Hercules, CA).
Collagen ELISA
Collagen ELISAs were performed using previously reported methods (24, 25) with minor alterations. Briefly, 96-well Costar EIA/RIA (enzyme immunoassay/radioimmunoassay) plates were coated with 100 µl of 100 mM carbonate-bicarbonate buffer. Collagen standards (type I collagen, Sigma Chemical) and 100-µl media samples were added directly to the buffer in triplicate, and plates were incubated at 4°C overnight. Wells were washed three times with PBS that contained 0.05% Tween 20 (PBS-Tween 20) buffer. Nonspecific binding sites were blocked by 1 h of incubation with 250 µl/well of 1% BSA in Tris-buffered saline (TBS, 100 mM Tris·HCl with 150 mM NaCl). After the wells were washed with PBS three times, 100 µl of primary antibody (1:1,000 dilution, rabbit anti-rat type I collagen polyclonal antibody, Bio Design International; Kennebunk, ME) in TBS was added and wells were incubated for 1 h at room temperature. Plates were washed five times before addition of 100 µl of secondary antibody (1:20,000 dilution, goat anti-rabbit monoclonal antibody with alkaline phosphatase conjugate, Sigma Chemical) in TBS and incubated at room temperature for 1 h. Wells were then washed five times with PBS-Tween 20 and twice with distilled water before 100 µl (1 mg/ml) of the color-development agent p-nitrophenyl phosphate in 1.0 M diethanolamine buffer was added. Optical density readings at 405 nm were taken at half-hour intervals with the Vmax microplate reader (Molecular Devices; Sunnyvale, CA).
Conversion of Exogenous Big ET-1 to ET-1 by MyoFbs
Confluent myoFbs (100-mm dishes in triplicate; 2 million cells/dish)
were washed three times (3 x 10 ml/dish) with serum-free media and then
incubated in serum-free media (5 ml/dish) with and without Big ET-1 (10 nM) in
the absence and presence of the ECE-1 inhibitor phosphoramidon (0.1 µM) for
20 h. Media were collected, processed as above, and analyzed for ET-1
contents.
Western Immunoblotting for ET receptors
Confluent myoFbs were washed with PBS, and cell lysates were prepared (12). Aliquots with 50 µg of protein were electrophoretically fractionated on 10% SDS-PAGE minigels and were electroblotted onto a nitrocellulose membrane. The membrane was sequentially incubated in TBS (pH 7.4) that contained 5% dry milk for 30 min and diluted (1:200) rat anti-ETA and anti-ETB receptor primary antibody (Alomone Laboratories) in 5% Blotto (Bio-Rad nonfat dry milk powder in TBS) for 12 h on a shaker at 4°C. The blot was washed with TBS that contained 0.1% Tween 20 and was incubated with a 1:1,000 dilution of horseradish peroxidase-conjugated goat anti-rabbit secondary antibody (Sigma Chemical) in 5% Blotto for 1 h at room temperature, washed with TBS, and incubated with the peroxidase substrate. Immunoreactive bands were visualized within 10 min using an ECL detection kit (Amersham Pharmacia Biotech; Piscataway, NJ).
Statistical Analysis
Results are reported as means ± SE for a minimum of five
determinations, each of which was performed either in duplicate or triplicate.
Statistical analysis was performed using one-way ANOVA with P 
0.05 considered significant.
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RESULTS |
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TOPABSTRACTMATERIALS AND METHODSRESULTSDISCUSSIONDISCLOSURESREFERENCES |
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Expression of the prepro-ET-1 gene (ppET1, the only known precursor gene that encodes Big ET-1) and ECE-1 were examined in myoFbs by semiquantitative RT-PCR technique. RT-PCR studies resulted in PCR products of predicted sizes for ppET1 (334 bp) and ECE-1 (529 bp) (Fig. 1). These results demonstrated that myoFbs express ppET1 and the key enzyme ECE-1 that converts Big ET-1 to the active peptide ET-1. The PCR products for ET-1 and ECE-1 were of predicted sizes, and their identities were confirmed by cycle sequencing.
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Determination of Big ET-1 and ET-1 Contents in MyoFb Culture Media
The elaboration of Big ET-1 and the production of ET-1 in the media of serum-deprived myoFbs were studied in a time-dependent manner. The results indicated that myoFbs generate both Big ET-1 and ET-1 (Figs. 2 and 3). The time-dependent pattern of Big ET-1 elaboration (0.5, 2, 4, and 8 h) indicated maximum levels of Big ET-1 in myoFb culture media at 2 and 4 h. In another set of experiments with an 8-h incubation in the presence of phosphoramidon (a specific inhibitor for ECE-1), Big ET-1 levels were increased two- to threefold (Fig. 2, fifth bar), which suggests that the gradual drop seen in Big ET-1 concentration at 4 and 8 h is due to its conversion to ET-1 by ECE-1 (Fig. 2, third and fourth bars). The production of ET-1 was time dependent (6, 12, 24, and 36 h) with the highest levels of ET-1 found at 24 h. ET-1 concentrations after 24 h in the presence of bosentan (10–6 M) were highly elevated (90 pg/ml) compared with 24 h without bosentan (Fig. 3, fifth bar), because a significant portion of ET-1 loss due to its binding to cellular ET receptors was prevented by bosentan.
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Protease Involved in Conversion of Big ET-1 to ET-1 and Effects of Exogenous Big ET-1 on MyoFb ET-1 Production
ECE-1 is a membrane-bound, phosphoramidon-sensitive, zinc metalloprotease that converts Big ET-1 to ET-1. The presence of ECE-1 was detected in the myoFb cell preparation, which converted exogenous Big ET-1 to ET-1 and was blocked by 100 µM phosphoramidon (Fig. 4).
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The ability of confluent myoFbs to generate ET-1 was significantly
(P 0.05) increased in the presence of exogenous Big ET-1
(Fig. 4, second bar) and was
significantly reduced in the presence of the ECE-1 inhibitor phosphoramidon
(Fig. 4, third bar), which
suggests possible involvement of an active metalloprotease ECE-1 in generating
ET-1 de novo.
Expression of ETA and ETB Receptors by RT-PCR
Using a standard semiquantitative RT-PCR method (5, 12, 14), we examined the expression of both ETA and ETB receptors in myoFbs. The results clearly demonstrated the amplification of a single predicted band of PCR product for ETA (787 bp) and ETB (919 bp) receptors, respectively (Fig. 5), which suggests that myoFbs express both ETA and ETB receptors.
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Western Immunoblotting for ETA and ETB Receptors
Cultured myoFb and coronary endothelial cell (as positive control) pellets
were used to detect the presence of ET receptors by Western blot analysis
using ETA and ETB receptor-specific antibodies. Results
obtained from Western immunoblotting revealed two major bands of 
60- and
39-kDa protein for the ETA receptor and a single band of 40
kDa for the ETB receptor (Fig.
6). These protein bands were within the predicted range as
specified by the commercial supplier of these antibodies. These results
confirm that cultured myoFbs express both ETA and ETB
receptors.
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ET-1-Receptor Binding Studies
The presence of ET receptors was also confirmed by ET-1-receptor binding assays using 125I-labeled ET-1 as the radioligand (13). ET-1 receptor densities as determined at the saturation of binding for fibroblasts and myoFbs were 31.80 ± 1.03 and 35.89 ± 1.93 fmol/mg of protein, respectively, which suggests that these were the active target cells for the autocoid influence of ETs on the induction of type I collagen gene expression.
Type I Collagen mRNA Induction by ET-1
The influence of ET on type I collagen mRNA expression was evaluated by
Northern blot analysis, and the results indicated an induction of type I
collagen mRNA by ET at the concentrations studied
(10–7 to 10–11 M;
Fig. 7). As shown in
Fig. 7, the upregulation of
type I collagen was effectively blocked by the ETA and
ETB receptor antagonist bosentan (10–6
M), which suggests that induction of 1-type I collagen mRNA
is an ET receptor-mediated mechanism.
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Type I Collagen Synthesis by ELISA
The influence of ET-1 on type I collagen protein synthesis was evaluated by
ELISA, and the results indicated a dose-dependent increase in type I collagen
synthesis induced by ET-1 (Fig.
8). The upregulation of type I collagen synthesis by ET-1 was
significantly higher (P 0.05 at
10–10 to 10–8 M),
which was attenuated with bosentan treatment
(Fig. 8, seventh bar;
10–9 M ET-1 plus 10–6
M bosentan). These results clearly indicate that induction of type I collagen
expression by ET-1 was at both transcriptional (mRNA; see
Fig. 7) and translational
(protein; see Fig. 8)
levels.
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DISCUSSION |
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TOPABSTRACTMATERIALS AND METHODSRESULTSDISCUSSIONDISCLOSURESREFERENCES |
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Our concurrent objective of this investigation was to demonstrate the expression of the key enzyme ECE-1 by myoFbs. The data showed the presence of mRNA for ECE-1 in myoFbs, and addition of exogenous Big ET-1 to myoFb culture media significantly increased ET-1 levels. This suggests the presence of ECE-1 activity, which was significantly reduced in the presence of the ECE-1 inhibitor phosphoramidon. Expression of phosphoramidon-sensitive ECE-1 by myoFbs strengthens the fact that these cells have all the necessary elements to produce biologically active ET-1 from ET precursors.
Earlier reports have shown that ET-1 is mitogenic and that it stimulates
fibroblast proliferation (40).
Media obtained from bovine aortic endothelial cells induced collagen
accumulation and protein formation by human fibroblasts, which suggests that
an endothelial cell-derived factor can stimulate collagen production by
fibroblasts (42). We have
previously demonstrated a positive influence of ET-1 on cardiac fibroblasts
(10) and vascular smooth
muscle cell (25) collagen
expression. To determine whether myoFbs, a cell type that is isolated from
infarcted rat heart, is responsive to ET-1, we investigated the presence of
specific receptors for ET-1 for an autocrine influence. Through RT-PCR and
Western blot analyses, we found the presence of both ETA- and
ETB-receptor subtypes and also demonstrated a significant
125I-labeled ET binding to myoFb cell membranes. In our studies, we
have demonstrated that myoFbs isolated from the site of infarction not only
express ANG II (12) and
transforming growth factor (TGF)-1
(4), but also express
ppET1, ECE-1, and ETA and ETB receptors thus
implicating de novo expression of ET by myoFbs and suggesting a possible role
for locally generated ET-1 in tissue regeneration and remodeling at the site
of MI.
As stated earlier, when Oie et al. (21) examined infarcted regions of rat heart with immunohistochemistry, they found heavy immunostaining for ET-1 in the granulation tissue at the site of infarction, which indicated that wound-healing myoFbs found at this site may be responsible for producing ET. Apart from the vascular endothelial cells, the possibility of myocytes, smooth muscle cells, and fibroblasts expressing ET cannot be ruled out, but these are not the classical wound-healing cells that are found at the site of tissue repair or remodeling. However, these cells can be the target cells for the paracrine action of ET as they express ET receptors (13, 25).
The regulation of ET-1 expression in these cells is unclear and it may be
similar to the autoregulation that is reported for endothelial cells
(28), or it could be
influenced by TGF-1 and/or other cytokines. Understanding the
regulatory aspects of ET generation by myoFbs at the site of infarction is
important and has become the subject of our ongoing study. A study by Boffa et
al. (2) on renal vasculature
showed ET as a mediator of fibrogenic action of ANG II. The fibrotic response
induced by ANG II was mitigated by bosentan, a nonselective ET-receptor
antagonist. Similarly, it was shown that TGF-1 is known to
upregulate ET-1 expression and production in several cell types
(17,
20,
33,
40). Studies by Sun et al.
demonstrated that ANG II plays a vital role in collagen turnover and
remodeling in several tissue-injury models including myocardium
(36,
37). Our earlier study
(15) on tissue regeneration in
response to injury in a rat-pouch tissue model showed the production of ANG
II, which regulates TGF-1. Previous studies from our group
conclusively showed that myoFbs produce ANG II, TGF-1, and
VEGF (4,
5,
12), and the present study
confirms the de novo production of ET and its receptors. From these studies,
it is evident that myoFbs play a unique role in tissue repair and regeneration
by expressing ANG II, ET, VEGF, and TGF-1, which modulate
collagen turnover in response to injury in different organs.
Collectively, results from the present study demonstrate the generation of
Big ET-1 and ET-1 de novo by cultured myoFbs isolated from infarct scar tissue
and the influence of ET on type I collagen expression. Such locally generated
ET-1, ANG II, TGF-1, and VEGF could influence collagen
turnover and tissue repair and remodeling at and remote to the site of injury
in an autocrine/paracrine manner as well as in cell-cell and cell-matrix
contractions, which promote matrix remodeling and scar thinning.
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DISCLOSURES |
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TOPABSTRACTMATERIALS AND METHODSRESULTSDISCUSSIONDISCLOSURESREFERENCES |
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Part of this work was performed at the Dalton Cardiovascular Research Center, Univ. of Missouri, Columbia, MO 65211.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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REFERENCES |
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TOPABSTRACTMATERIALS AND METHODSRESULTSDISCUSSIONDISCLOSURESREFERENCES |
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1 in cardiac fibroblasts and myofibroblasts. J Mol
Cell Cardiol 29:
1947–1958, 1997.[ISI][Medline]
stimulates the expression
of endothelin mRNA by vascular endothelial cells. Biochem Biophys
Res Commun 159:
1435–1440, 1989.[ISI][Medline]
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