(Circulation. 2001;103:993.)
© 2001 American Heart Association, Inc.
Basic Science Reports |
From the Cardiovascular Division, Department of Medicine, Brigham and Womens Hospital, Harvard Medical School, Boston, Mass (Y.F., P.L., E.R., C.C.H., M.A.); and the Biosafety Research Center, Foods, Drugs, and Pesticides, Shizuoka (M.E., Y.H.), and the Institute of Experimental Animals, Kobe University School of Medicine, Kobe (M.S.), Japan.
Correspondence to Masanori Aikawa, MD, PhD, Cardiovascular Division, Department of Medicine, Brigham and Womens Hospital, Harvard Medical School, 221 Longwood Ave, LMRC 307, Boston, MA 02115. E-mail maikawa{at}rics.bwh.harvard.edu
| Abstract |
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Methods and ResultsWe administered equihypocholesterolemic doses of pravastatin (a hydrophilic statin, 50 mg · kg-1 · d-1, n=9), fluvastatin (a cell-permeant lipophilic statin, 20 mg · kg-1 · d-1, n=10), or placebo (n=10) to mature Watanabe heritable hyperlipidemic rabbits for 52 weeks. The fluvastatin group achieved a much higher peak plasma concentration (23.7 µmol/L) than did the pravastatin group (1.3 µmol/L) under these conditions. Immunohistochemistry revealed that MMP-1, MMP-3, and MMP-9 expression by macrophages in the intima was lower in both the pravastatin and fluvastatin groups than in the placebo group, whereas there was no difference in macrophage numbers. Numbers of intimal smooth muscle cells (SMCs) (identified by immunohistochemistry) and expression of type I procollagen mRNA (detected by in situ hybridization), however, were significantly higher in the pravastatin group than in the fluvastatin group. Treatment with pravastatin, but not fluvastatin, preserved interstitial collagen content in vivo (detected by picrosirius red polarization). In vitro, fluvastatin, but not pravastatin, decreased numbers of rabbit and human aortic SMCs without altering procollagen I mRNA expression.
ConclusionsThis study showed that statins can reduce MMP expression in atheroma and that cell-permeant statins can decrease SMC number and collagen gene expression in vivo.
Key Words: collagen muscle, smooth atherosclerosis
| Introduction |
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SMCs synthesize the interstitial collagens, major constituents of the arterial extracellular matrix responsible for resistance to rupture of atherosclerotic plaques. We have proposed the balance between collagen production and degradation as a key determinant of plaque disruption, the trigger of most acute coronary events. Our previous studies have shown that lipid lowering by diet10 or cerivastatin11 in atherosclerotic rabbits reduces expression of matrix-degrading proteinases by lesional macrophages and increases accumulation of interstitial collagen in atheroma, suggesting that reduced activity of proteinases permits accumulation of extracellular matrix macromolecules.10 The effect of lipid lowering on collagen gene expression by SMCs in atheroma, however, has not been determined. Recent in vitro data indicated that certain lipophilic, but not hydrophilic, statins directly induce SMC apoptosis.12 Because of reduced collagen production, the death of SMCs might substantially impair the strength of the plaque. This study aimed to examine the regulation of collagen gene expression during lipid lowering in vivo. We also evaluated differential effects of lipophilic and hydrophilic statins on collagen synthesis by SMCs in vitro and in atheroma of Watanabe heritable hyperlipidemic (WHHL) rabbits, animals with endogenous hypercholesterolemia.
| Methods |
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Plasma Cholesterol and Triglyceride
Levels
Peripheral blood was collected from the ear artery
under local anesthesia, and plasma cholesterol and triglyceride
concentrations were measured by an automated analyzer (Type 7170,
Hitachi).
Tissue Preparation
Rabbits were euthanized by administration of
intravenous sodium pentobarbital (25 mg/kg). Heparin (40 U/kg) was
injected simultaneously to avoid blood clotting. The aortas were
excised and rinsed briefly with DMEM (BioWhittaker) without serum. The
distal portion of the aortic arch (2 mm above the ligamentum
arteriosum) was excised and fixed with 4% paraformaldehyde for in situ
hybridization for procollagen I mRNA; immunohistochemistry for
macrophages, matrix metalloproteinase (MMP)-1, MMP-3, and MMP-9;
picrosirius red staining; and terminal deoxynucleotidyl transferase
(TdT)mediated dUTP-biotin nick end-labeling (TUNEL) staining. These
tissues were embedded in paraffin by conventional procedures and
sectioned in 5-µm slices.
In Situ Hybridization
Four oligonucleotide probes corresponding to rabbit
mRNA for
2 type I
collagen13 were synthesized:
for antisense probes, 5'-ACCTTGG-CTACCCTGAGAA-3',
5'-CCGTTGTGTCCCTTTATGC-3', 5'-CATAGTCCTTGGGTCTGAG-3', and
5'-GACATGCTTCTT-GGCCTTG-3'; for corresponding sense
probes, 5'-TTCTCA-GGGTAGCCAAGGT-3',
5'-GCATAAAGGGACACAACGG-3', 5'-CTCAGACCCAAGGACTATG-3', and
5'-CAAGGCCAAGAA-GCATGTC-3', labeled with 5'-fluorescein and
purified by high-performance liquid chromatography (Integrated DNA
Technologies, Inc). The specificity of these oligonucleotides was
confirmed by sequencing of reverse transcriptionpolymerase chain
reaction (RT-PCR) products.
In situ hybridization was performed with the Hyb-Probe Detection System (Shandon/Lipshaw) as follows. After deparaffinization, slides were treated with proteinase K for 8 minutes and then dehydrated. The slides were incubated for 10 minutes at 65°C and then for 2 hours at 37°C in a humid chamber with 1 ng/µL of the oligonucleotides in hybridization buffer composed of 50% formamide, 0.6 mol/L NaCl, 10% dextran sulfate, 50 mmol/L Tris pH 7.5, 0.1% sodium pyrophosphate, Denhardts solution, and 5 mmol/L EDTA. After incubation, slides were washed with PBS (pH 7.4) containing 0.1% Triton X-100 and incubated with blocking solution for 10 minutes. Slides were then incubated with alkaline phosphataseconjugated detection antibody against fluorescein for 30 minutes. Alkaline phosphatase activity was revealed by NBT/BCIP chromogen solution. Slides were counterstained with methyl green and mounted.
Immunohistochemistry
Mouse monoclonal antibodies against rabbit
macrophages (RAM11, Dako Corp), human MMP-1 (collagenase-1, IM35L,
Oncogene Research Products), rabbit MMP-3 (stromelysin-1, IM45L,
Oncogene Research Products), human MMP-9 (gelatinase-B, IM10L, Oncogene
Research Products), human
-smooth muscle actin (1A4, Dako A/S), and
nonimmune mouse IgG (as a negative control) were applied, and
immunohistochemistry was performed by the ABC
method.
Picrosirius Red Polarization for
Collagen
We performed sirius red polarization by a modified
Junqueiras method as previously
described.10 14 The
stained sections were observed under polarized light and photographed
with the same strength of light by digital image capture (Flash Point
FPG).
TUNEL Staining
The TUNEL procedure was performed with the In
Situ Apoptosis Kit (Apo-Tag, Oncor). Proteinase K (20 µg/mL) was
applied to tissue sections for 5 minutes at room temperature. Sections
were incubated with the TdT enzyme for 2 hours at 37°C. Alkaline
phosphataselabeled streptavidin solution was applied for 30 minutes
and followed by exposure of sections to Dako AEC substrate kit
substrate for 3 to 5 minutes. The next day, immunohistochemistry for
-actin was performed on the same section as described above with
vector blue (SK5300, Vector Laboratories) and counterstained with
methyl green.
SMC Culture
Rabbit arterial SMCs (passage 6) obtained from
the aortas of New Zealand White rabbits and SMCs obtained from
human aortas (passage 2) by explant outgrowth were seeded in 6-well
dishes for determinations of cell numbers and in flasks (150
cm2) for RNA extraction. They were incubated
with DMEM supplemented with 10% FCS. Twenty-four hours later, the
medium was changed to DMEM with 0.4% FCS, and the cells were incubated
for 48 hours. The medium was then replaced with DMEM containing 10%
FCS in the presence or absence of statins, and the cells were incubated
for an additional 72 hours at 37°C. Cell number was evaluated by
CellTiter 96 Aqueous One Solution Cell Proliferation Assay (MTS
assay, Promega).
Reverse TranscriptionPolymerase Chain
Reaction
RNA was isolated from arterial SMCs with RNeasy and
RNase-Free DNase (Qiagen). Then RT-PCR was performed with Superscript
II RNase H- reverse transcriptase.
Oligonucleotide probes were synthesized for procollagen I mRNA: 5'
site, 5'-CATAGTCCTTGGGTCTGAG-3'; 3' site,
5'-GCATAAAGGGA-CACAACGG-3'.13
For GAPDH (internal control): 5' site, 5'-CGAGTACGTGGTGGAATC-3'; 3'
site, 5'-AGGGATGATGTT-CTGGGC-3'. Polymerase chain
reaction amplification used the following conditions: denaturation for
1 minute at 94°C, annealing for 1 minute at 55°C, and elongation
for 1 minute at 72°C for 25 cycles. RNA levels were normalized by
amplification of GAPDH.
Quantitative Analysis for Histology and
Statistics
Quantification of immunohistochemistry for
macrophages, MMP-1, MMP-3, MMP-9,
-smooth muscle actin, and sirius
red polarization was performed by computer-assisted color image
analysis (Image Pro Plus). We divided MMP-1, MMP-3, and
MMP-9positive areas within macrophage-containing regions by the whole
macrophage area, denoted MMP-1(+)/macrophages, MMP-3(+)/macrophages,
and MMP-9(+)/macrophages. The positive areas were calculated in Excel
(Microsoft). Analyses of in situ hybridization for procollagen I mRNA,
immunohistochemistry for
-smooth muscle actin, and TUNEL-positive
cells within SMC-containing regions were performed manually by 2
different observers who counted all positive cells in a blinded manner.
Interobserver correlation was excellent
(r=0.98). Statistical testing
used 1-way ANOVA followed by the post hoc
test.
| Results |
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Under these conditions, fluvastatin achieved much higher blood levels than did pravastatin (Cmax, 1.29±0.28 and 23.70±2.75* µmol/L; AUC, 11.9±2.7 and 124.0±11.8* µmol · L-1 · h-1 for the pravastatin and fluvastatin groups, respectively, *P<0.01).
Statins Reduced MMP-1, MMP-3, and MMP-9 Protein
Expression by Macrophages
There was no significant difference in the
intimal cross-sectional area or the macrophage-containing area in the
control, pravastatin, and fluvastatin groups (intimal area, 5.59±0.61,
5.44±0.55, and 5.64±0.40 mm2,
P=0.58; RAM-11positive area,
0.62±0.34, 0.71±0.20, and 0.88±0.38 mm2,
P=0.30 by ANOVA, for the
control, pravastatin, and fluvastatin groups, respectively). There was
no signal in negative controls.
We further quantified MMP-1, MMP-3, and MMP-9positive
areas within macrophage-containing regions
(Figure 1A
). The fluvastatin group had significantly less
MMP-1 positivity within macrophage areas
(Figure 1B
), and the pravastatin and fluvastatin groups had
significantly less MMP-3 or MMP-9positive areas within the
macrophage areas compared with the control group
(Figure 1C
and 1D
).
|
Pravastatin Treatment Produced More Smooth
Muscle Accumulation and Higher Procollagen I mRNA Levels
Immunohistochemistry for
-smooth muscle actin showed
that the areas and numbers of immunopositive cells were higher in the
atheroma of WHHL rabbits in the pravastatin group than in the
fluvastatin and control groups
(Figure 2
). Procollagen I mRNA expression (detected by in
situ hybridization) was also significantly higher in the pravastatin
than in the fluvastatin or the control group
(Figure 3
). There was no significant difference in the ratio
of procollagen I mRNA expression to
-actinpositive cells among the
3 groups
(Figure 3C
and 3D
). These results suggest that the increased
procollagen I mRNA levels in the pravastatin group resulted from an
increased number of SMCs.
|
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Pravastatin Increases Collagen
Content
Picrosirius red polarization showed significantly
increased interstitial collagen content in the intima of WHHL rabbits
in the pravastatin group compared with the fluvastatin
andcontrol groups
(Figure 4
). The adventitia constitutively showed copious
fibrillar collagen in all 3 groups.
|
Death of SMCs
Some in vitro studies have suggested that statins
promote apoptosis of SMCs in
vitro.12 Therefore, to
examine DNA fragmentation in SMCs in atheroma of WHHL rabbits, TUNEL
staining was performed. There was no significant difference in the
numbers of TUNEL-positive cells in the 3 groups
(Figure 5
).
|
Fluvastatin Inhibits SMC Growth Much More
Potently Than Pravastatin but Neither Statin Affects Collagen mRNA
Levels In Vitro
In vitro experiments examined potential direct effects
of pravastatin and fluvastatin on growth and procollagen I gene
expression in rabbit and in human aortic SMCs. Fluvastatin, but not
pravastatin, reduced growth of both rabbit and human aortic SMCs in a
dose-dependent manner
(Figure 6
). There was no significant difference in rabbit
procollagen I mRNA expression among control, pravastatin-treated, and
fluvastatin-treated cells over 72 hours at 2 different doses of statins
(Figure 7
).
|
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| Discussion |
|---|
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Ruptured human atherosclerotic plaques often have a thin fibrous cap with little collagen and few SMCs.2 SMC loss might result from cell death due in part to apoptosis in human atheroma17 18 and in hypercholesterolemic rabbits.19 In fact, hypercholesterolemia reduces SMC number and collagen content and causes mechanical weakening of rabbit atheroma.20 Shiomi et al21 demonstrated that atheroma of WHHL rabbits that had undergone cholesterol reduction with pravastatin contain more SMCs and collagen accumulation than those of placebo-treated animals. Kockx et al19 also reported that lipid lowering decreases apoptotic vascular cells in rabbit atheroma. In the present study, the tendency toward a decreased number of TUNEL-positive cells furnished one potential mechanism by which lesions in the pravastatin group contained more SMCs and collagen than those in the control group. Thus, lipid lowering may suppress the death of SMCs and in turn stabilize the plaque.
Lipophilic statins can suppress proliferation and induce apoptosis of SMCs in vitro. Corsini et al22 showed that serum from patients treated with fluvastatin, but not pravastatin, inhibited the proliferation of cultured human arterial SMCs. Buemi et al23 also reported that serum from patients treated with fluvastatin significantly reduced proliferation and increased apoptosis in human SMCs. Guijarro et al12 showed that lipophilic statins, such as atorvastatin, simvastatin, or lovastatin, but not hydrophilic pravastatin, induced apoptosis of rat SMCs in a dose-dependent manner. Soma et al24 previously described an antiproliferative effect of fluvastatin, but not pravastatin, on SMCs in acute vascular injury in nonatherosclerotic normocholesterolemic rabbits. The present study showed that fluvastatin concomitantly decreased SMC and collagen accumulation in atheroma of WHHL rabbits in vivo.
Macrophage activation also plays an important role in the pathogenesis of acute coronary syndromes.4 25 Lesional macrophages produce proteolytic enzymes, including members of the MMP, cysteine protease, and plasminogen activator families. Thus, macrophage-related proteolysis within atheroma may weaken the protective fibrous cap and promote plaque rupture.26 We previously demonstrated that dietary lipid lowering reduces the number of macrophages expressing MMPs and tissue factor in rabbit atheroma.10 27 In addition to lower macrophage numbers, reduced macrophage activation could be an important therapeutic goal. Statins such as fluvastatin or simvastatin reduce MMP-9 secretion by macrophages in culture.28 The present study demonstrates that pravastatin or fluvastatin significantly reduces MMP expression but not macrophage number in vivo, which suggests decreased macrophage activation. This alteration should promote plaque stabilization.
We have hypothesized that a dynamic balance between collagen synthesis and degradation determines collagen content in the fibrous cap of the plaque. Evidence that such a balance operates in vivo and hence regulates plaque stability, however, remains scant. Lipid lowering can affect both SMC phenotype and macrophage activation. We previously demonstrated that dietary lipid lowering promotes accumulation of mature SMCs in rabbit atheroma.29 SMCs in the modulated phenotype (so-called "synthetic"-state cells) can synthesize 2- to 3-fold more collagen than mature phenotype ("contractile"-state cells) in vitro.30 Thus, lipid lowering may reduce collagen production by SMCs. Lipid lowering, however, increased the collagen content of rabbit atheroma.10 This finding may reflect a greater local decrease in proteolytic activity than in collagen synthesis. These results indicate that a marked reduction in collagen degradation can outweigh a slight decrease in collagen synthesis, leading to an increase in collagen accumulation in atheroma.
This study was not designed to test the clinical utility of the agents used but rather to test the hypothesis that statins can differentially affect variables related to plaque stability in humans in an atherosclerotic animal with very high blood levels of fluvastatin. We aimed to explore in vivo the controversial notion of "pleiotropic" effects of statins. Indeed, our results establish a distinct difference in in vivo effects of 2 statins on spontaneous atheroma in WHHL rabbits. These results should not be extrapolated directly to the use of these 2 agents in humans, however, because the levels of fluvastatin in this experiment exceed those expected in humans. Nonetheless, these results strongly support the concept that statins can have different in vivo effects on SMC accumulation and collagen production independent of cholesterol lowering. Our findings further provide important information for development of more effective therapies for atherosclerosis.
| Acknowledgments |
|---|
Received July 31, 2000; revision received August 23, 2000; accepted August 23, 2000.
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J. G. Robinson, B. Smith, N. Maheshwari, and H. Schrott Pleiotropic Effects of Statins: Benefit Beyond Cholesterol Reduction?: A Meta-Regression Analysis J. Am. Coll. Cardiol., November 15, 2005; 46(10): 1855 - 1862. [Abstract] [Full Text] [PDF] |
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S. H. Han, M. J. Quon, and K. K. Koh Beneficial Vascular and Metabolic Effects of Peroxisome Proliferator-Activated Receptor-{alpha} Activators Hypertension, November 1, 2005; 46(5): 1086 - 1092. [Abstract] [Full Text] [PDF] |
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J.-O Deguchi, E. Aikawa, P. Libby, J. R. Vachon, M. Inada, S. M. Krane, P. Whittaker, and M. Aikawa Matrix Metalloproteinase-13/Collagenase-3 Deletion Promotes Collagen Accumulation and Organization in Mouse Atherosclerotic Plaques Circulation, October 25, 2005; 112(17): 2708 - 2715. [Abstract] [Full Text] [PDF] |
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R. Virmani, F. D. Kolodgie, A. P. Burke, A. V. Finn, H. K. Gold, T. N. Tulenko, S. P. Wrenn, and J. Narula Atherosclerotic Plaque Progression and Vulnerability to Rupture: Angiogenesis as a Source of Intraplaque Hemorrhage Arterioscler Thromb Vasc Biol, October 1, 2005; 25(10): 2054 - 2061. [Abstract] [Full Text] [PDF] |
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K. Sakamoto, T. Murata, H. Chuma, M. Hori, and H. Ozaki Fluvastatin Prevents Vascular Hyperplasia by Inhibiting Phenotype Modulation and Proliferation Through Extracellular Signal-Regulated Kinase 1 and 2 and p38 Mitogen-Activated Protein Kinase Inactivation in Organ-Cultured Artery Arterioscler Thromb Vasc Biol, February 1, 2005; 25(2): 327 - 333. [Abstract] [Full Text] [PDF] |
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M. Torzewski, P. X. Shaw, K.-R. Han, B. Shortal, K. J. Lackner, J. L. Witztum, W. Palinski, and S. Tsimikas Reduced In Vivo Aortic Uptake of Radiolabeled Oxidation-Specific Antibodies Reflects Changes in Plaque Composition Consistent With Plaque Stabilization Arterioscler Thromb Vasc Biol, December 1, 2004; 24(12): 2307 - 2312. [Abstract] [Full Text] [PDF] |
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S Van Doornum, G McColl, and I P Wicks Atorvastatin reduces arterial stiffness in patients with rheumatoid arthritis Ann Rheum Dis, December 1, 2004; 63(12): 1571 - 1575. [Abstract] [Full Text] [PDF] |
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P. L. Weissberg Noninvasive Imaging of Atherosclerosis: The Biology Behind the Pictures J. Nucl. Med., November 1, 2004; 45(11): 1794 - 1795. [Full Text] [PDF] |
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F. A. Spencer, G. C. Fonarow, P. D. Frederick, R. S. Wright, N. Every, R. J. Goldberg, J. M. Gore, W. Dong, R. C. Becker, W. French, et al. Early Withdrawal of Statin Therapy in Patients With Non-ST-Segment Elevation Myocardial Infarction: National Registry of Myocardial Infarction Arch Intern Med, October 25, 2004; 164(19): 2162 - 2168. [Abstract] [Full Text] [PDF] |
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Y. Fukumoto, J.-o Deguchi, P. Libby, E. Rabkin-Aikawa, Y. Sakata, M. T. Chin, C. C. Hill, P. R. Lawler, N. Varo, F. J. Schoen, et al. Genetically Determined Resistance to Collagenase Action Augments Interstitial Collagen Accumulation in Atherosclerotic Plaques Circulation, October 5, 2004; 110(14): 1953 - 1959. [Abstract] [Full Text] [PDF] |
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P E Lazzerini, P L Capecchi, F Nerucci, A Fioravanti, F Chellini, M Piccini, S Bisogno, R Marcolongo, and F Laghi Pasini Simvastatin reduces MMP-3 level in interleukin 1{beta} stimulated human chondrocyte culture Ann Rheum Dis, July 1, 2004; 63(7): 867 - 869. [Abstract] [Full Text] [PDF] |
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J. Davignon Beneficial Cardiovascular Pleiotropic Effects of Statins Circulation, June 15, 2004; 109(23_suppl_1): III-39 - III-43. [Abstract] [Full Text] |
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F. A. Spencer, J. Allegrone, R. J. Goldberg, J. M. Gore, K. A.A. Fox, C. B. Granger, R. H. Mehta, D. Brieger, and the GRACE Investigators* Association of Statin Therapy with Outcomes of Acute Coronary Syndromes: The GRACE Study Ann Intern Med, June 1, 2004; 140(11): 857 - 866. [Abstract] [Full Text] [PDF] |
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U. Schonbeck and P. Libby Inflammation, Immunity, and HMG-CoA Reductase Inhibitors: Statins as Antiinflammatory Agents? Circulation, June 1, 2004; 109(21_suppl_1): II-18 - II-26. [Abstract] [Full Text] [PDF] |
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F.M Sacks Do statins play a role in the early management of the acute coronary syndrome? Eur. Heart J. Suppl., March 1, 2004; 6(suppl_A): A32 - A36. [Abstract] [Full Text] [PDF] |
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Y. Matsumoto, T. Uwatoku, K. Oi, K. Abe, T. Hattori, K. Morishige, Y. Eto, Y. Fukumoto, K.-i. Nakamura, Y. Shibata, et al. Long-Term Inhibition of Rho-Kinase Suppresses Neointimal Formation After Stent Implantation in Porcine Coronary Arteries: Involvement of Multiple Mechanisms Arterioscler Thromb Vasc Biol, January 1, 2004; 24(1): 181 - 186. [Abstract] [Full Text] [PDF] |
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C. Maack, T. Kartes, H. Kilter, H.-J. Schafers, G. Nickenig, M. Bohm, and U. Laufs Oxygen Free Radical Release in Human Failing Myocardium Is Associated With Increased Activity of Rac1-GTPase and Represents a Target for Statin Treatment Circulation, September 30, 2003; 108(13): 1567 - 1574. [Abstract] [Full Text] [PDF] |
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Y. Fukumoto, H. Tsutsui, M. Tsuchihashi, A. Masumoto, A. Takeshita, and Cholesterol Embolism Study(CHEST) Investigators The incidence and risk factors of cholesterol embolization syndrome, a complication of cardiac catheterization: a prospective study J. Am. Coll. Cardiol., July 16, 2003; 42(2): 211 - 216. [Abstract] [Full Text] [PDF] |
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J. Genest and T. R. Pedersen Prevention of Cardiovascular Ischemic Events: High-Risk and Secondary Prevention Circulation, April 22, 2003; 107(15): 2059 - 2065. [Full Text] [PDF] |
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P. K. Shah Mechanisms of plaque vulnerability and rupture J. Am. Coll. Cardiol., February 19, 2003; 41(4_Suppl_S): 15S - 22S. [Abstract] [Full Text] [PDF] |
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P.O Bonetti, L.O Lerman, C Napoli, and A Lerman Statin effects beyond lipid lowering--are they clinically relevant? Eur. Heart J., February 1, 2003; 24(3): 225 - 248. [Full Text] [PDF] |
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B. Axisa, I. M. Loftus, A. R. Naylor, S. Goodall, L. Jones, P. R.F. Bell, M. M. Thompson, and C. Napoli Prospective, Randomized, Double-Blind Trial Investigating the Effect of Doxycycline on Matrix Metalloproteinase Expression Within Atherosclerotic Carotid Plaques * Editorial Comment Stroke, December 1, 2002; 33(12): 2858 - 2864. [Abstract] [Full Text] [PDF] |
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L. G. Bucciarelli, T. Wendt, W. Qu, Y. Lu, E. Lalla, L. L. Rong, M. T. Goova, B. Moser, T. Kislinger, D. C. Lee, et al. RAGE Blockade Stabilizes Established Atherosclerosis in Diabetic Apolipoprotein E-Null Mice Circulation, November 26, 2002; 106(22): 2827 - 2835. [Abstract] [Full Text] [PDF] |
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W. Palinski and C. Napoli Unraveling Pleiotropic Effects of Statins on Plaque Rupture Arterioscler Thromb Vasc Biol, November 1, 2002; 22(11): 1745 - 1750. [Full Text] [PDF] |
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J. L. Dixon, S. Shen, J. P. Vuchetich, E. Wysocka, G. Y. Sun, and M. Sturek Increased atherosclerosis in diabetic dyslipidemic swine: protection by atorvastatin involves decreased VLDL triglycerides but minimal effects on the lipoprotein profile J. Lipid Res., October 1, 2002; 43(10): 1618 - 1629. [Abstract] [Full Text] [PDF] |
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K. K. Koh, J. W. Son, J. Y. Ahn, D. K. Jin, H. S. Kim, Y. M. Choi, D. S. Kim, E.-M. Jeong, G. S. Park, I. S. Choi, et al. Comparative Effects of Diet and Statin on NO Bioactivity and Matrix Metalloproteinases in Hypercholesterolemic Patients With Coronary Artery Disease Arterioscler Thromb Vasc Biol, September 1, 2002; 22(9): e19 - 23. [Abstract] [Full Text] [PDF] |
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G. K. Sukhova, J. K. Williams, and P. Libby Statins Reduce Inflammation in Atheroma of Nonhuman Primates Independent of Effects on Serum Cholesterol Arterioscler Thromb Vasc Biol, September 1, 2002; 22(9): 1452 - 1458. [Abstract] [Full Text] [PDF] |
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H. L. Kennedy and R. S. Rosenson Physicians' interpretation of "class effects": A need for thoughtful re-evaluation J. Am. Coll. Cardiol., July 3, 2002; 40(1): 19 - 26. [Abstract] [Full Text] [PDF] |
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L. K. Newby, A. Kristinsson, M. V. Bhapkar, P. E. Aylward, A. P. Dimas, W. W. Klein, D. K. McGuire, D. J. Moliterno, F. W. A. Verheugt, W. D. Weaver, et al. Early Statin Initiation and Outcomes in Patients With Acute Coronary Syndromes JAMA, June 19, 2002; 287(23): 3087 - 3095. [Abstract] [Full Text] [PDF] |
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G.J. Blake and P.M. Ridker C-reactive protein and prognosis after percutaneous coronary intervention Eur. Heart J., June 2, 2002; 23(12): 923 - 925. [Full Text] [PDF] |
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W. Palinski and S. Tsimikas Immunomodulatory Effects of Statins: Mechanisms and Potential Impact on Arteriosclerosis J. Am. Soc. Nephrol., June 1, 2002; 13(6): 1673 - 1681. [Abstract] [Full Text] [PDF] |
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S. Itoh, S. Umemoto, M. Hiromoto, Y. Toma, Y. Tomochika, S. Aoyagi, M. Tanaka, T. Fujii, and M. Matsuzaki Importance of NAD(P)H Oxidase-Mediated Oxidative Stress and Contractile Type Smooth Muscle Myosin Heavy Chain SM2 at the Early Stage of Atherosclerosis Circulation, May 14, 2002; 105(19): 2288 - 2295. [Abstract] [Full Text] [PDF] |
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I. Loftus and M. Thompson The role of matrix metalloproteinases in vascular disease Vascular Medicine, May 1, 2002; 7(2): 117 - 133. [Abstract] [PDF] |
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P. Libby and M. Aikawa Vitamin C, Collagen, and Cracks in the Plaque Circulation, March 26, 2002; 105(12): 1396 - 1398. [Full Text] [PDF] |
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P. Libby, P. M. Ridker, and A. Maseri Inflammation and Atherosclerosis Circulation, March 5, 2002; 105(9): 1135 - 1143. [Abstract] [Full Text] [PDF] |
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S.M. Cobbe How best to combat the enemies? Lipid lowering Eur. Heart J. Suppl., February 1, 2002; 4(suppl_A): A48 - A52. [Abstract] [PDF] |
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H. V. Anderson, J. McNatt, F. J. Clubb, M. Herman, J.-P. Maffrand, F. DeClerck, C. Ahn, L. M. Buja, and J. T. Willerson Platelet Inhibition Reduces Cyclic Flow Variations and Neointimal Proliferation in Normal and Hypercholesterolemic-Atherosclerotic Canine Coronary Arteries Circulation, November 6, 2001; 104(19): 2331 - 2337. [Abstract] [Full Text] [PDF] |
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M. Takemoto and J. K. Liao Pleiotropic Effects of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors Arterioscler Thromb Vasc Biol, November 1, 2001; 21(11): 1712 - 1719. [Abstract] [Full Text] [PDF] |
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G. J. Blake and P. M. Ridker Novel Clinical Markers of Vascular Wall Inflammation Circ. Res., October 26, 2001; 89(9): 763 - 771. [Abstract] [Full Text] [PDF] |
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B. R. Kwak and F. Mach Statins Inhibit Leukocyte Recruitment: New Evidence for Their Anti-Inflammatory Properties Arterioscler Thromb Vasc Biol, August 1, 2001; 21(8): 1256 - 1258. [Full Text] [PDF] |
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R. Dechend, A. Fiebeler, J.-K. Park, D. N. Muller, J. Theuer, E. Mervaala, M. Bieringer, D. Gulba, R. Dietz, F. C. Luft, et al. Amelioration of Angiotensin II-Induced Cardiac Injury by a 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitor Circulation, July 31, 2001; 104(5): 576 - 581. [Abstract] [Full Text] [PDF] |
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M. A. Albert, E. Danielson, N. Rifai, P. M Ridker, and for the PRINCE Investigators Effect of Statin Therapy on C-Reactive Protein Levels: The Pravastatin Inflammation/CRP Evaluation (PRINCE): A Randomized Trial and Cohort Study JAMA, July 4, 2001; 286(1): 64 - 70. [Abstract] [Full Text] [PDF] |
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P. K. Shah, J. Yano, O. Reyes, K.-Y. Chyu, S. Kaul, C. L. Bisgaier, S. Drake, and B. Cercek High-Dose Recombinant Apolipoprotein A-IMilano Mobilizes Tissue Cholesterol and Rapidly Reduces Plaque Lipid and Macrophage Content in Apolipoprotein E-Deficient Mice : Potential Implications for Acute Plaque Stabilization Circulation, June 26, 2001; 103(25): 3047 - 3050. [Abstract] [Full Text] [PDF] |
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