This Article Abstract Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Geng, Y.-J. Articles by Libby, P. Search for Related Content PubMed PubMed Citation Articles by Geng, Y.-J. Articles by Libby, P.

(Arteriosclerosis, Thrombosis, and Vascular Biology. 1996;16:19-27.)
© 1996 American Heart Association, Inc.

Articles

Apoptosis of Vascular Smooth Muscle Cells Induced by In Vitro Stimulation With Interferon-, Tumor Necrosis Factor–, and Interleukin-1ß

Yong-Jian Geng; Qi Wu; Maria Muszynski; Göran K. Hansson; Peter Libby

From the Vascular Medicine and Atherosclerosis Unit, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass, and the King Gustaf V Research Institute (G.K.H.), Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.

Correspondence to Dr Peter Libby, Vascular Medicine and Atherosclerosis Unit, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave, Boston, MA 02115.

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Abstract Recent studies have documented evidence for the death of smooth muscle cells (SMCs) within advanced human atheroma. These lesions contain macrophages and T lymphocytes in addition to SMCs. We therefore investigated whether interferon- (IFN-), a cytokine secreted by T lymphocytes, or interleukin-1ß (IL-1ß) and tumor necrosis factor– (TNF-), two cytokines characteristically produced by activated macrophages, can trigger apoptosis of vascular SMCs. Simultaneous treatment with IFN- and TNF- and/or IL-1ß but not with each cytokine alone promoted death of human and rat SMCs. Exposure for 48 hours to a combination of IFN- (400 U/mL), TNF- (400 U/mL), and IL-1ß (100 U/mL) significantly (P<.001) increased the accumulation of oligonucleosomes comprising DNA fragments and histones in human SMCs. Electrophoresis of genomic DNA showed internucleosomal fragments of genomic DNA isolated from the cytokine-cotreated SMCs of both humans and rats. These cells exhibited morphological changes typical of apoptosis, including cell shrinkage, membrane blebbing, chromatin condensation, and nuclear fragmentation. In situ 3' end labeling of DNA fragments with terminal transferase confirmed the fragmentation of genomic DNA in these cells. Simultaneous treatment with IFN- and TNF- or IL-1ß induced elaboration of nitrite, an end product of nitric oxide, in rat but not human SMCs. N^G-monomethyl-L-arginine inhibited nitrite accumulation and also partly blocked cytokine-induced apoptosis of rat SMCs but had little effect on human SMCs, suggesting operation of both nitric oxide–dependent and –independent mechanisms for cytokine-induced apoptosis in vascular SMCs. Production of immune cytokines by vascular cells and/or infiltrating leukocytes may regulate apoptotic death of SMCs during atherogenesis.

Key Words: smooth muscle cells • cell death • nitric oxide • cytokines • atherosclerosis

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
In addition to lipids and connective tissue, atherosclerotic lesions consist of SMCs, macrophages, and T lymphocytes.¹ During the prolonged process of atherogenesis, complex interactions between the vascular cells and infiltrating immune cells yield local production of a great variety of biologically active substances such as cytokines and growth factors.^{2 3} These bioactive substances may in turn regulate cell functions, such as replication, differentiation, and death, in a paracrine or autocrine fashion and consequently influence cellularity and morphogenesis of the vessel wall.

The cytokines IFN-^{4 5} (secreted mainly by activated T cells) and IL-1^{6 7} and TNF-⁸ (products of activated macrophages as well as SMCs themselves) can regulate gene expression, differentiation, and growth of vascular SMCs in vitro and in vivo. Although IL-1⁷ and TNF-⁸ stimulate but IFN- inhibits SMC proliferation,^{4 9} these cytokines share many biological actions. For example, at least in rodent cells, IFN-, TNF-, and IL-1, together or alone, can induce expression of NOS.^{10 11} NO produced by the cytokine-inducible form of NOS exerts many well-known effects on cells, including the ability to kill microbial pathogens and tumor cells.¹²

Cell death occurs in advanced atherosclerotic lesions, often resulting in formation of hypocellular fibrous zones and a lipid-rich "necrotic" core. Recent reports provide evidence that apoptosis, a form of programmed cell death,¹³ can mediate some of the cell death in human atherosclerotic lesions.^{14 15 16} SMCs isolated from atherosclerotic arteries undergo apoptosis more frequently than do cells from normal vessels.¹⁷ In situ detection of DNA fragments demonstrates that many SMCs in plaques^{15 16} and in balloon-injured arteries^{16 18} bear this marker of apoptosis.

The mechanisms that trigger apoptosis in atherosclerotic lesions remain unknown. Cytokines can promote apoptosis in some cell types: IL-1 induces apoptosis of pancreatic cells¹⁹ and chondrocytes²⁰ in an NO-dependent pattern; TNF- promotes apoptosis of endothelial cells,²¹ and IFN- triggers apoptosis of vascular SMCs, which overexpress functional c-myc after transfection with c-myc cDNA.²² Since cytokine-producing cells (eg, macrophages and T lymphocytes) abound in advanced atherosclerotic lesions,^{2 23} we hypothesized that cytokines might contribute to apoptosis of vascular SMCs during atherogenesis. The present study tested whether cultured SMCs undergo apoptosis when exposed to recombinant cytokines.

	Methods

Top Abstract Introduction Methods Results Discussion References

 
Reagents
The recombinant cytokines used in this study were rat IFN- (Holland Biotechnology), human IFN- (Genzyme Corp), murine TNF- (Genentech Inc), and human TNF- and IL-1ß (Endogen, Inc). Sulfanilamide and N-(1-naphthyl)ethylenediamine hydrochloride were obtained from Merck. L-NMMA was from Calbiochem Corp. Acridine orange, ethidium bromide, and propidium iodide were purchased from Sigma Chemical Co, and YOYO-1, a sensitive DNA-binding fluorochrome, was from Molecular Probes, Inc.

Vascular SMC Isolation and Culture
Human²⁴ and rat⁴ vascular SMCs were isolated from the tunica media of aortas of 35- to 45-year-old organ donors without overt atherosclerosis and 6-week-old Sprague-Dawley rats, respectively. The cells were cultured in Dulbecco's minimal essential medium (GIBCO) supplemented with 10% FCS and antibiotics.²⁴ Cells were identified as vascular SMCs by their characteristic hills–and-valleys growth pattern and by immunofluorescence with anti––smooth muscle actin monoclonal antibody. They were passed by trypsinization, plated at a density of 2x10⁴ cells/mL, and used for experiments at passages 2 through 7. Cells at a subconfluent density were treated with IFN-, IL-1ß, and TNF- alone or together. In some experiments, L-NMMA (500 µmol/L) was added together with the cytokines to block endogenous NO synthesis.

Cell Viability
Cell viability was determined by fluorochrome staining. SMCs (10⁴ cells/chamber) were cultured in eight-chamber slides. The cells were treated with 400 U/mL IFN-, 400 U/mL TNF-, and 100 U/mL IL-1ß for 24, 48, 72, or 96 hours. At the end of incubation, the nucleic acid–binding fluorescent dyes acridine orange and ethidium bromide (10 µg/mL each in culture medium) were added to the cultures. After the slides were stained, they were coverslipped and observed by fluorescent microscopy, and viable (green fluorescent nuclei) and nonviable (red or orange fluorescent nuclei) cells were counted. For each sample, at least 200 cells were counted in different high-power fields. The percentage of viable cells was determined by the following formula: percent cell viability=100x(number of viable cells)/(total number of cells).

Cell Morphology and Nuclear Staining
Cell morphology was examined by phase-contrast microscopy and recorded by microphotography during incubation with cytokines. For visualization of nuclei, cells were cultured in eight-chamber slides and treated with or without cytokines. At the end of incubation, cells were fixed in ice-cold 4% formaldehyde. After washing with PBS containing Tween 20 (0.5%), cells were stained with 1 µg/mL YOYO-1 in PBS for 5 minutes, mounted in 70% glycerol in PBS, and observed under an Olympus fluorescent microscope.

Enzyme Immunoassay of Oligonucleosomes
Internucleosomal DNA fragmentation characteristic of apoptosis occurs several hours before breakdown of the plasma membrane of apoptotic cells. Enrichment of mononucleosomes or oligonucleosomes in cytokine-treated and untreated SMCs was quantitatively determined by sandwich-enzyme immunoassay with a cell-death detection ELISA kit purchased from Boehringer Mannheim Corp. Briefly, 5x10⁴ cells cultured in 24-well plates were treated with IFN-, TNF-, and IL-1ß for 48 hours. At the end of the incubation, culture medium was removed to an Eppendorf tube and centrifuged at 20 000g. The resulting pellets contained oligonucleosomal fragments. Meanwhile, adherent SMCs were permeabilized in the sample buffer containing Tween 20. The supernatants containing the cytoplasmic oligonucleosomes released from SMC nuclei were combined with the oligonucleosomal fragments in medium. The combined supernatants (100 µL) were transferred to a 96-well microplate precoated with monoclonal antibody against histone-4. After incubation for 1 hour at room temperature and washing, oligonucleosomal DNA fragments bound to the microplate were detected by using monoclonal anti-DNA antibody conjugated with the enzyme peroxidase. 2,2'-Azinodi-[3-ethylbenzthiazoline sulfonate] was used as the enzyme substrate, and colored product was measured by spectrophotometry at 405 nm.

In Situ Detection of Apoptotic Cells
Cells undergoing apoptosis can accumulate internucleosomal DNA fragments in their nuclei. In situ detection of apoptotic cells was performed by using TUNEL with an ApoTag in situ apoptosis detection kit (Oncor Inc). Briefly, cells were cultured in eight-chamber slides and treated with or without cytokines for 72 hours. After cytokine treatment, cells were washed in PBS, fixed, incubated with 5 µg/mL proteinase K for 10 minutes, and then labeled with digoxigenin-conjugated dUTP and the enzyme terminal deoxyribonucleotide transferase. Labeled DNA fragments were stained with anti-digoxigenin monoclonal antibody linked with peroxidase. The chromogenic substrate diaminobenzidine was used as the substrate for peroxidase.

Flow Cytometry
SMCs were cultured in six-well plates in Dulbecco's minimal essential medium containing 10% FCS. After incubation with or without cytokines and trypsinization, cells were suspended in fresh medium containing 50 µg/mL propidium iodide for 5 minutes at 37°C and then subjected to flow cytometry on a fluorescence-activated cell sorter flow cytometer immediately after incubation. A light-scatter gate was set up to eliminate cell debris from analysis. Cellular propidium iodide fluorescence signal was recorded on the FL2 channel and analyzed by using Lysys II software.

DNA Fragmentation Analysis
Cells (5x10⁶) were lysed in 1 mL DNA extraction solution containing 20 mmol/L Tris-HCl, pH 7.4, 0.1 mol/L NaCl, 5 mmol/L EDTA, and 0.5% sodium dodecyl sulfate. The lysates were incubated with 100 µg/mL proteinase K at 37°C for 16 hours. After incubation, 1 mL of phenol/chloroform (1:1) was mixed well with the enzyme-digested cell lysates, and the mixture was centrifuged at 20 000g for 20 minutes. DNA in the upper (aqueous) phase was incubated with 5 µg/mL DNase-free RNase A at 37°C for 1 hour and extracted with phenol/chloroform again. DNA was collected by precipitation with 1 mL isopropanol and 0.1 mL of 5 mol/L NaCl at -20°C overnight. After centrifugation, the resulting DNA pellets were washed with 75% ethanol and air dried. DNA was dissolved in 10 mmol/L Tris-HCl and 1 mmol/L EDTA, and its concentration was determined at 260 nm by spectrophotometry. DNA electrophoresis was carried out in 1.5% agarose gels containing 1 µg/mL ethidium bromide, and DNA fragments were visualized by exposing the gel to UV light.

Nitrite Assay
In cell cultures, the majority of NO produced by cytokine-stimulated SMCs is converted into nitrite by reaction with ambient oxygen. We therefore measured nitrite accumulation in SMCs by using the Griess reagent, composed of 2.9 mmol/L sulfanilic acid and 0.2 mmol/L N-(1-naphthyl)ethylenediamine hydrochloride in 5% phosphatic acid.^{10 11} Briefly, culture medium was incubated with an equal volume of the Griess reagent at room temperature for 30 minutes. The colored product of the diazotization reaction was spectrophotometrically quantified at 540 nm by using a microplate ELISA reader. Sodium nitrite dissolved in the same medium was used as standard.

Statistical Analysis
Differences between means were evaluated by using two-tailed Student's t tests. ANOVA in cell viability was carried out by using the ANOVA program in Excel (Microsoft Co). Significance was established when the probability value was less than .05.

	Results

Top Abstract Introduction Methods Results Discussion References

 
Death of Vascular SMCs Exposed to Cytokines
We examined the viability of cultured human and rat vascular SMCs by staining the cells with the fluorochromes acridine orange and ethidium bromide. Viable cells excluded ethidium bromide but were permeable to acridine orange, which reacts with DNA to yield green nuclear fluorescence and with RNA to produce red fluorescence in the cytoplasm (Fig 1). Nonviable cells show red ethidium bromide fluorescence in their nuclei due to ethidium bromide entry (Fig 1d). Under basal conditions, cultures of both human and rat SMCs contained few nonviable cells (Fig 1a and 1e). Treatment with either IFN- (400 U/mL), TNF- (400 U/mL), or IL-1ß (100 U/mL) alone for 24 hours did not increase the percentage of dead cells, and prolongation of the cytokine incubation time to 48 and 72 hours slightly increased the number of dead cells in the single cytokine–treated SMCs (Figs 1 and 2). However, a combination of these cytokines induced much higher levels of cell death compared with the control cultures or those treated with a single cytokine. Simultaneous exposure to IFN-, TNF-, and IL-1ß caused higher levels of cell death than did the double treatments (Fig 2).

View larger version (53K): [in this window] [in a new window]   Figure 1. Photomicrographs of human (a through d) and rat (e and f) SMCs cultured in eight-well chamber slides and treated with IFN- and TNF-. After incubation, cells were stained with acridine orange and ethidium bromide at 50 µg/mL each and examined by fluorescent microscopy. a, Untreated human control (arrow shows dividing cells); b, IFN- 400 U/mL; c, TNF- 400 U/mL; d, IFN- with TNF- (arrow shows a dead cell); e, untreated rat control; and f, IFN- with TNF- (original magnification x200).

View larger version (17K): [in this window] [in a new window]   Figure 2. Line graph. Human SMCs cultured in medium containing 10% FCS were treated with IFN- (400 U/mL), TNF- (400 U/mL), and IL-1ß (100 U/mL) alone or in combination. Viable cells were enumerated based on fluorochrome staining with 50 µg/mL each acridine orange and ethidium bromide. Dead cells showed red nuclear fluorescence (Fig 1). Data represent means of four cultures (coefficient of variation <10%). *P<.05 vs untreated controls.

Flow cytometric determination of cell viability with the DNA-binding dye propidium iodide further demonstrated similar cytokine effects on rat SMCs, which are more easily detached during apoptosis than are human SMCs. Few rat SMCs died when cultured in normal medium containing either no cytokines or an individual cytokine (Fig 3). More than 95% of unstimulated rat SMCs excluded propidium iodide, and exposure to either IFN- or TNF- alone did not reduce cell viability (Fig 3). However, simultaneous treatment with both IFN- and TNF- at 400 U/mL each for 72 hours reduced cell viability from 96±1% to 48±8% (P<.01), indicating the synergy in induction of cell death between the two cytokines (Fig 3). Nonviable cells exhibited high but varying levels of propidium iodide fluorescent intensity (Fig 3), suggesting that DNA degradation might occur in these nonviable cells, leading to a wide range of their cellular DNA content.

View larger version (24K): [in this window] [in a new window]   Figure 3. Rat SMCs were treated with IFN- and/or TNF- (400 U/mL each) for 72 hours. In some experiments, L-NMMA (500 µmol/L) was added together with the cytokines. After incubation, cells were collected by trypsinization, stained in 50 µg/mL propidium iodide for 5 minutes, and analyzed by flow cytometry.

Morphological Characterization of Vascular SMCs Undergoing Apoptosis
Phase-contrast microscopy showed morphological changes characteristic of apoptosis in cytokine-treated human and rat SMCs. When exposed to IFN-, TNF-, and IL-1ß, some human SMCs shrank and retracted from their neighbor cells. Their membranes appeared blebbed, and the cytoplasm condensed (Fig 4). The surviving cells also showed certain degrees of morphological change, with an elongated and bipolar appearance (Figs 1 and 4). We used the ultrasensitive DNA-binding dye YOYO-1, which discloses nuclear morphology better than does acridine orange or ethidium bromide, to examine human SMCs treated with or without the cytokines. Staining with YOYO-1 clearly visualized fragmented nuclei with condensed chromatin, and some nuclei fragmented and formed apoptotic bodies (Fig 5). The morphological changes induced in SMCs by cytokine stimulation were distinguishable from those caused by treatment with high concentrations of H₂O₂, which kills SMCs very rapidly. In contrast to the cells treated with cytokines, SMCs exposed to H₂O₂ appeared swollen rather than shrunken, but their connections with adjacent cells remained intact (Fig 4h). In contrast to cytokine-treated cells, H₂O₂-treated SMCs showed a relatively normal nuclear morphology, as illustrated by YOYO-1 staining (Fig 5d). These observations suggest that cytokine treatment induces SMC death via apoptosis, whereas at high concentrations, H₂O₂ causes SMC death via primary necrosis or oncosis, a form of nonprogrammed cell death.²⁵ Rat SMCs similarly treated developed pyknotic nuclei as well (Fig 5f).

View larger version (135K): [in this window] [in a new window]   Figure 4. Photomicrographs. a through d, Human SMCs cultured in medium containing 10% FCS were incubated with or without IFN- (500 U/mL), TNF- (500 U/mL), and IL-1ß (100 U/mL). After 72 hours, cells were observed by phase-contrast microscopy. b and d, Higher magnification of squares in a and c, respectively (original magnification x100 [a and c]; x400 [b and d]). e through h, Rat SMCs cultured in medium containing 10% FCS were incubated with or without IFN- and TNF- (400 U/mL each) or with 0.1% H2O2. After incubation, cells were observed by phase-contrast microscopy (original magnification x400 [e through h]).

View larger version (98K): [in this window] [in a new window]   Figure 5. Photomicrographs showing nuclear morphology of cytokine-treated human and rat SMCs stained with YOYO-1. Human (a through d) and rat (e and f) SMCs cultured in eight-chamber slides were incubated with or without IFN- (400 U/mL), TNF- (400 U/mL), and IL-1ß (100 U/mL). After 72 hours, cells were fixed, permeabilized with 0.5% Tween 20, and stained with 1 µg/mL YOYO-1. Arrows indicate fragmented nuclei (original magnification x1000).

Accumulation of Oligonucleosomes in Vascular SMCs Undergoing Apoptosis
Cells undergoing apoptosis can release mononucleosomes or oligonucleosomes comprising DNA fragments and histones from their nuclei into the cytoplasm or even into the extracellular compartment.^{26 27} We examined the accumulation of oligonucleosomes in the cytokine-treated cells by using ELISA with anti-histone and anti-DNA antibodies to verify the occurrence of apoptosis. We observed a significantly increased accumulation of oligonucleosomes in human SMCs treated simultaneously with IFN-, TNF-, and IL-1ß for 48 hours (Fig 6). In contrast, few oligonucleosomes accumulated in the untreated cultures (Fig 6). In the presence of TNF- (400 U/mL) and IL-1ß (100 U/mL), IFN- increased accumulation of oligonucleosomes in human SMCs in a concentration-dependent manner (Fig 7).

View larger version (15K): [in this window] [in a new window]   Figure 6. Bar graph. Human SMCs were cultured in 24-well plates and treated with IFN- (400 U/mL), TNF- (400 U/mL), and IL-1ß (100 U/mL). After treatment, cells were permeabilized and centrifuged at 20 000g. Oligonucleosomes in the supernatants were determined by ELISA. Data are mean±SEM of four to six cultures. *P<.05; **P<.01.

View larger version (15K): [in this window] [in a new window]   Figure 7. Bar graph. Human SMCs were cultured in 24-well plates and treated with IFN- at 0, 50, 100, 200, 400, or 800 U/mL in the presence of TNF- (400 U/mL) and IL-1ß (100 U/mL). After treatment, cells were permeabilized, and media were collected and centrifuged at 20 000g. Oligonucleosomes in the combined supernatants were determined by ELISA. Data are mean±SEM of four to six cultures. *P<.05; **P<.01.

We further visualized DNA fragments in situ by using the TUNEL technique. Few cells (<5%) in the cultures with or without each cytokine alone showed TUNEL staining (Fig 8). However, 34±4% of human SMCs in the cultures cotreated with IFN-, TNF-, and IL-1ß for 48 hours showed positive staining with TUNEL (P<.05 versus untreated controls, n=3) (Fig 8). Some cells with TUNEL-positive nuclei also showed TUNEL staining in their cytoplasm, indicating the presence of cytoplasmic DNA fragments in the cells undergoing apoptosis (Fig 8).

View larger version (143K): [in this window] [in a new window]   Figure 8. Photomicrographs of in situ detection of DNA fragments. Human SMCs treated with IFN- (400 U/mL), TNF- (400 U/mL), and IL-1ß (100 U/mL) were fixed, washed, and stained by TUNEL. The brown color as developed in a peroxidase substrate system represents the positive areas. Quantification of nuclear labeling was performed by counting the percentage of TUNEL-positive cells in 200 cells in random fields for each condition. Arrows indicate TUNEL-positive nuclei in c and d (original magnification x400).

We also evaluated internucleosomal DNA fragmentation, a biochemical marker for apoptosis, by assessing the size of genomic DNA isolated from the cytokine-treated and untreated SMCs by using agarose gel electrophoresis (Fig 9). Most DNA extracted from both human (Fig 9A) and rat (Fig 9B) SMCs showed a high molecular weight (>20 kb). Internucleosomal DNA fragments at 180 to 200 bp or multiples appeared in SMCs treated simultaneously with IFN-, TNF-, and/or IL-1ß (Fig 9), indicating the occurrence of apoptosis in these cells. In contrast, no appreciable levels of DNA fragmentation existed in the untreated control cells (Fig 9).

View larger version (37K): [in this window] [in a new window]   Figure 9. Electrophoretic analysis of internucleosomal DNA fragmentation in cytokine-treated human and rat SMCs. Genomic DNA was isolated by phenol/chloroform extraction from human (A) and rat (B) SMCs treated with or without IFN- (500 U/mL), TNF- (500 U/mL), IL-1ß (100 U/mL), L-NMMA appears in both panels, but the original legend specifies the amount only for panel B.and/or L-NMMA (500 µmol/L) for 72 hours. DNA (10 µg/lane) was loaded into 1.5% agarose gels containing ethidium bromide. After electrophoresis, DNA bands were visualized under UV light. + and indicate presence and absence, respectively. Lane 7 in B shows DNA size markers.

NO Synthesis and Apoptosis in Vascular SMCs Stimulated With Cytokines
The cytokines IFN-, TNF-, and IL-1ß can together elicit expression of the inducible form of NOS by vascular SMCs.¹⁰ Such augmented NO synthesis can mediate apoptosis of murine macrophages²⁸ and human chondrocytes.²⁹ We therefore tested whether enzymatically synthesized NO mediates cytokine-induced apoptosis in vascular SMCs. In rat SMCs, stimulation with a combination of IFN- (400 U/mL) and TNF- (400 U/mL) induced high levels of nitrite accumulation (Fig 10). However, human SMCs so treated did not produce substantial amounts of NO in response to the same cytokines (Fig 10).

View larger version (30K): [in this window] [in a new window]   Figure 10. Bar graph. Rat and human vascular SMCs were incubated with IFN- and TNF- (400 U/mL each) for 48 hours. After incubation, 100 µL medium of the cultures was mixed with an equal volume of Griess reagent. Nitrite concentration in the medium was determined spectrophotometrically at 540 nm with sodium nitrite as standard. Data are mean±SEM of four cultures. *P<.05; **P<.01.

In rat SMCs cotreated with IFN- and TNF-, the addition of the NOS inhibitor L-NMMA (500 µmol/L) significantly increased the number of viable cells as demonstrated by flow cytometry (Fig 3) and fluorescent microscopy (Table) but diminished nitrite accumulation (Fig 10). L-NMMA also inhibited internucleosomal DNA fragmentation in the cytokine-cotreated rat SMCs (Fig 9B). However, this NOS inhibitor did not completely block the cytokine-induced apoptosis. Furthermore, L-NMMA did not appear to alter the viability (Table) of the cytokine-treated human vascular SMCs, which produced little nitrite. This result suggests that cytokines induce apoptosis of vascular SMCs by both NO-dependent and -independent pathways.

View this table: [in this window] [in a new window]   Table 1. Cell Viability of Human and Rat SMCs Treated With IFN- and TNF- in the Presence or Absence of L-NMMA

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
Apoptosis appears to require an exogenous signal and a complex endogenous gene-controlled apoptotic machinery.^{30 31} We sought here to test whether cytokines produced by inflammatory cells trigger death of vascular SMCs. By using a combination of techniques for analyzing markers for apoptosis, we now demonstrate that when combined, the cytokines IFN-, TNF-, and IL-1ß can induce apoptosis of cultured human and rat SMCs. The data support the notion that SMCs in atherosclerotic lesions may undergo apoptosis in response to the proinflammatory cytokines produced locally by activated macrophages and T lymphocytes as a consequence of the ongoing local immune and inflammatory response characteristic of atherogenesis.¹⁵

Vascular SMCs exhibit heterogeneity both in vivo and in vitro. Normal arterial intima contain very small numbers of SMCs. During atherogenesis, increased numbers of SMCs exist in the thickening intima; these SMCs show substantial differences in gene expression and function from medial SMCs. However, many in vitro and in vivo studies^{2 3} argue that in in vitro culture, medial SMCs can undergo modification during passages and gain some of the biological properties of neointimal SMCs during atherogenesis; thus they are widely used as target cells in in vitro experiments.

It is likely that different subpopulations of SMCs may respond differently to factors such as cytokines. We found that some SMCs survived cytokine treatment even at high concentrations while their neighbor cells died and that the surviving cells showed a morphology distinct from that of untreated cells. Recent studies on the effects of IFN- on c-myc–transfected rat SMCs demonstrate that both apoptotic and mitotic figures can exist in the same cell cultures.²² These findings indicate that cytokines may selectively act on certain subpopulations of SMCs, thus leading to depletion of these cells from tissues or modulating their phenotype.

Prolonged exposure to IL-1 alters the morphology and growth pattern of human SMCs, resulting in accumulation of cells with an elongated, bipolar shape.⁷ Treatment with IFN- suppresses expression of –smooth muscle actin in rat SMCs⁹ while augmenting the expression of major histocompatibility complex class II genes in both rat⁴ and human³² SMCs. In atherosclerosis, SMCs in the intimal lesions differ from those of the tunica media in phenotype, but the underlying mechanism remains uncertain. Cytokines produced from and evoked by infiltrating immune cells are likely involved in phenotypic change of SMCs by inducing apoptosis of certain subtypes of SMCs that are sensitive to the cytokines.

Our experimental results indicate that the individual cytokines alone do not suffice to cause apoptosis of either rat or human SMCs. Exposure to either IL-1^{6 7} or TNF-⁸ can stimulate SMC proliferation, whereas IFN-^{4 5 9} inhibits SMC proliferation. These findings suggest that these cytokines may activate different signal transduction pathways that synergize or antagonize each other in regulation of cell turnover.

Several different signal transduction pathways may mediate the induction of apoptosis by these proinflammatory cytokines. Among them, the L-arginine/NOS pathway may serve as a potential trigger of apoptosis, as many studies have demonstrated that IFN-, TNF-, and IL-1, alone or synergistically, induce synthesis of NO from L-arginine in various types of rodent cells, including vascular SMCs.¹² We observed that cytokine-stimulated, NO-generating rat SMCs died via apoptosis, and addition of the NOS inhibitor L-NMMA could partially block these cytokine effects. This result agrees well with the data from recent studies showing that NO mediates apoptosis of murine macrophages^{28 33} and their tumor target cells,³⁴ rat pancreatic beta-cells,¹⁹ and human chondrocytes.²⁹

However, it remains unclear how activation of NO synthesis leads to apoptosis in the cytokine-treated cells. We have shown that NO can form iron (II)–nitrosyl complexes with respiratory enzymes containing nonheme iron–sulfur clusters in mitochondria of rat SMCs and consequently inhibit respiration and ATP synthesis in cytokine-treated SMCs.^{10 11} NO also inactivates enzymes important for DNA synthesis and repair.¹² Recently, NO generated by cytokine-inducible NOS was found to stimulate the expression of the tumor suppressor gene p53 in RAW 264.7 macrophages and pancreatic RINm5F cells before apoptosis.³⁵ Expression of p53 can lead to cell death via apoptosis in various normal and malignant cell types.³⁵ These observations suggest that high levels of NO production catalyzed by cytokine-inducible NOS may promote apoptosis by multiple mechanisms.

Under the same experimental conditions, however, human vascular SMCs do not produce any appreciable levels of NO in response to IFN-, TNF-, and IL-1ß, in accord with recent work from other laboratories.³⁶ A similar situation exists in cultured human macrophages, which, unlike rodent macrophages, produce little NO when exposed to the cytokines.^{37 38 39} However, human hepatocytes⁴⁰ and chondrocytes⁴¹ can express inducible NOS and synthesize considerable amounts of NO in response to cytokine stimulation. Apparently, differences in cytokine induction of NO exist between species and cell types. The relatively high capacity for NO synthesis in rodent SMCs may partly explain why the rodent cells die via apoptosis when exposed to cytokines more readily than do human SMCs, which require more stringent conditions for NO production. Nonetheless, stimulation with the cytokines can provoke apoptosis of human SMCs even in the absence of NO production, and blocking of NO synthesis with L-NMMA cannot completely abolish apoptosis of rat SMCs induced by cytokines. It is likely that both NO-dependent and -independent mechanisms mediate the cytokine-induced apoptosis of vascular SMCs.

Much prior work on the cell biology of atherosclerosis has focused on SMC proliferation.³ During atherogenesis, arterial SMCs migrate from the tunica media to the intima, where they proliferate and synthesize extracellular matrix, contributing to focal thickening of the intima. In this context, apoptosis may serve as an adaptive mechanism to limit excessive cell replication and thickening of the intima. However, in advanced atheroma, SMC synthesis of extracellular matrix may actually stabilize the plaque structure. A high level of apoptotic cell death might impair maintenance of this matrix scaffolding of the fibrous cap of the plaque and thus predispose to plaque rupture, a major cause of acute atherosclerotic syndromes such as acute myocardial infarction or unstable angina. Therefore, dysregulation of apoptosis may influence both formation and complication of atherosclerosis and thereby provide a new therapeutic target.

	Selected Abbreviations and Acronyms

 

ELISA = enzyme-linked immunosorbent assay FCS = fetal calf serum IFN- = interferon- IL = interleukin L-NMMA = NG-monomethyl-L-arginine NO = nitric oxide NOS = nitric oxide synthase PBS = phosphate-buffered saline SMC = smooth muscle cell TNF- = tumor necrosis factor– TUNEL = terminal deoxyribonucleotide transferase–mediated dUTP nick end labeling YOYO-1 = benzoxazolium-4-quinolinium dimer

	Acknowledgments

 
This work was supported by National Institutes of Health grant HL-34636, the Swedish Medical Research Council (project No. 6816), and the Swedish Medical Heart-Lung Foundation. Yong-Jian Geng is a recipient of the ICRETT Award granted by the International Union Against Cancer, Geneva, Switzerland.

Received July 7, 1995; accepted September 15, 1995.

	References

Top Abstract Introduction Methods Results Discussion References

 
1. Jonasson L, Holm J, Skalli O, Bondjers G, Hansson GK. Regional accumulations of T cells, macrophages, and smooth muscle cells in human atherosclerotic plaque. Arteriosclerosis. 1986;6:131-138. [Abstract/Free Full Text]

2. Libby P, Hansson GK. Involvement of the immune system in human atherogenesis: current knowledge and unanswered questions. Lab Invest. 1991;64:5-15. [Medline] [Order article via Infotrieve]

3. Ross R. The pathogenesis of atherosclerosis: a perspective for the 1990s. Nature. 1993;362:801-809. [Medline] [Order article via Infotrieve]

4. Hansson GK, Jonasson L, Holm J, Clowes MM, Clowes AW. Interferon regulates vascular smooth muscle cell proliferation and Ia antigen expression in vivo and in vitro. Circ Res. 1988;63:712-719. [Abstract/Free Full Text]

5. Hansson GK, Holm J. Interferon-gamma inhibits arterial stenosis after injury. Circulation. 1991;84:1266-1272. [Abstract/Free Full Text]

6. Warner SJC, Auger KR, Libby P. Human interleukin-1 induces interleukin-1 gene expression in human vascular smooth muscle cells. J Exp Med. 1987;165:1316-1331. [Abstract/Free Full Text]

7. Libby P, Warner SJC, Friedman GB. Interleukin-1: a mitogen for human vascular smooth muscle cells that induces the release of growth-inhibitory prostanoids. J Clin Invest. 1988;88:487-498.

8. Warner SJC, Libby P. Human smooth muscle cells: target for and source of tumor necrosis factor. J Immunol. 1989;142:100-109. [Abstract]

9. Hansson GK, Hellstrand M, Rymo L, Rubbia L, Gabbiani G. Interferon-gamma inhibits proliferation and expression of differentiation-specific -smooth muscle actin in arterial smooth muscle cells. J Exp Med. 1989;170:1595-1608. [Abstract/Free Full Text]

10. Geng Y-J, Hansson GK, Holme E. Interferon-gamma and tumor necrosis factor synergize to induce nitric oxide production and inhibit mitochondrial respiration in vascular smooth muscle cells. Circ Res. 1992;71:1268-1276. [Abstract/Free Full Text]

11. Geng Y-J, Petersson AS, Wennmalm A, Hansson GK. Cytokine-induced expression of nitric oxide synthase results in nitrosylation of heme and nonheme iron proteins in vascular smooth muscle cells. Exp Cell Res. 1994;214:418-428. [Medline] [Order article via Infotrieve]

12. Nathan C. Nitric oxide as a secretory product of mammalian cells. FASEB J. 1992;6:3051-3064. [Abstract]

13. Kerr JFR, Wyllie AH, Currie AR. Apoptosis: a basic biological phenomenon with wide-ranging implications in tissue kinetics. Br J Cancer. 1972;26:239-257. [Medline] [Order article via Infotrieve]

14. Isner JM, Kearney M, Bortman S, Passeri J. Apoptosis in human atherosclerosis and restenosis. Circulation. 1995;91:2703-2711. [Abstract/Free Full Text]

15. Geng Y-J, Libby P. Evidence for apoptosis in advanced human atheroma: colocalization with interleukin-1ß converting enzyme. Am J Pathol. 1995;147:251-266. [Abstract]

16. Han DKM, Haudenshild CC, Hong MK, Thurmin A, Liau G. Evidence for a possible role of apoptosis in atherogenesis. Am J Pathol. 1995;147:267-277. [Abstract]

17. Bennett MR, Evan GI, Schwartz SM. Apoptosis of human vascular smooth muscle cells derived from normal vessels and coronary atherosclerotic plaques. J Clin Invest. 1995;95:2266-2274.

18. Bochaton-Piallat M-L, Gabbiani F, Redard M, Desmouliere A, Gabbiani G. Apoptosis participates in cellularity regulation during rat aortic intimal thickening. Am J Pathol. 1995;146:1-6. [Medline] [Order article via Infotrieve]

19. Ankarcrona M, Dypbukt JM, Brune B, Nicotera P. Interleukin-1 beta-induced nitric oxide production activates apoptosis in pancreatic RINm5F cells. Exp Cell Res. 1994;213:172-177. [Medline] [Order article via Infotrieve]

20. Blanco FJ, Ochs RL, Schwarz H, Martin L. Chondrocyte apoptosis induced by nitric oxide. Am J Pathol. 1995;146:75-85. [Abstract]

21. Robaye R, Mosselmans R, Fiers W, Dumont JE. Tumor necrosis factor induces apoptosis (programmed cell death) in normal endothelial cells `in vitro.' Am J Pathol. 1991;138:447-453. [Abstract]

22. Bennett MR, Evan GI, Newby AC. Deregulated expression of the c-myc oncogene abolishes inhibition of proliferation of rat vascular smooth muscle cells by serum reduction, interferon-, heparin, and cyclic nucleotide analogues and induces apoptosis. Circ Res. 1994;74:525-536. [Abstract/Free Full Text]

23. Hansson GK. Immune and inflammatory mechanisms in the development of atherosclerosis. Br Heart J. 1993;69:38-41.

24. Libby P, O'Brien KV. Culture of quiescent vascular smooth muscle cells in a defined serum-free medium. J Cell Physiol. 1983;115:217-233. [Medline] [Order article via Infotrieve]

25. Majno G, Joris I. Apoptosis, oncosis, and necrosis: an overview of cell death. Am J Pathol. 1995;146:3-15. [Abstract]

26. Wyllie AH, Kerr JFR, Currie AR. Cell death: the significance of apoptosis. Int Rev Cytol. 1980;68:251-306. [Medline] [Order article via Infotrieve]

27. Wyllie AH, Arends MJ, Morris RG, Walker SW, Evan G. The apoptosis endonuclease and its regulation. Semin Immunol. 1992;4:389-397. [Medline] [Order article via Infotrieve]

28. Albina JE, Cui S, Mateo RB, Reichner JS. Nitric oxide-mediated apoptosis in murine peritoneal macrophages. J Immunol. 1993;150:5080-5085. [Abstract]

29. Blanco FJ, Ochs RL, Schwarz H, Lotz M. Chondrocyte apoptosis induced by nitric oxide. Am J Pathol. 1995;146:75-85.

30. Wyllie AH. Apoptosis and the regulation of cell numbers in normal and neoplastic tissues: an overview. Cancer Metastasis Rev. 1992;11:95-103. [Medline] [Order article via Infotrieve]

31. Williams GT, Smith CA. Molecular regulation of apoptosis: genetic controls on cell death. Cell. 1993;74:777-779. [Medline] [Order article via Infotrieve]

32. Warner SJC, Friedman GB, Libby P. Regulation of major histocompatibility gene expression in human vascular smooth muscle cells. Arteriosclerosis. 1989;9:279-288. [Abstract/Free Full Text]

33. Sarih M, Souvannavong V, Adam A. Nitric oxide synthase induces macrophage death by apoptosis. Biochem Biophys Res Commun. 1993;191:503-508. [Medline] [Order article via Infotrieve]

34. Cui S, Reichner JS, Mateo RB, Albina JE. Activated murine macrophages induce apoptosis in tumor cells through nitric oxide-dependent or -independent mechanisms. Cancer Res. 1994;54:2462-2467. [Abstract/Free Full Text]

35. Messmer UK, Ankarcrona M, Nicotera P, Brune B. p53 Expression in nitric oxide-induced apoptosis. FEBS Lett. 1994;355:23-26. [Medline] [Order article via Infotrieve]

36. Beasley D, McGuiggin M. Interleukin 1 activates soluble guanylate cyclase in human vascular smooth muscle cells through a novel nitric oxide-independent pathway. J Exp Med. 1994;179:71-80. [Abstract/Free Full Text]

37. Sakai N, Milstien S. Availability of tetrahydrobiopterin is not a factor in the inability to detect nitric oxide production by human macrophages. Biochem Biophys Res Commun. 1993;193:378-383. [Medline] [Order article via Infotrieve]

38. Fuchs D, Murr C, Reibnegger G, Weiss G, Werner ER, Werner-Felmayer G, Wachter H. Nitric oxide synthase and antimicrobial armature of human macrophages. J Infect Dis. 1994;169:224-225. Letter. [Medline] [Order article via Infotrieve]

39. Eizirik DL. Nitric oxide synthase and antimicrobial armature of human macrophages. J Infect Dis. 1994;170:744-746. Letter. [Medline] [Order article via Infotrieve]

40. Geller DA, Lowenstein CJ, Shapiro RA, Nussler AK, Di SM, Wang SC, Nakayama DK, Simmons RL, Snyder SH, Billiar TR. Molecular cloning and expression of inducible nitric oxide synthase from human hepatocytes. Proc Natl Acad Sci U S A. 1993;90:3491-3495. [Abstract/Free Full Text]

41. Palmer RM, Hickery MS, Charles IG, Moncada S, Bayliss MT. Induction of nitric oxide synthase in human chondrocytes. Biochem Biophys Res Commun. 1993;193:398-405.[Medline] [Order article via Infotrieve]

This article has been cited by other articles:

				Y.-J. Yang, H.-Y. Qian, J. Huang, J.-J. Li, R.-L. Gao, K.-F. Dou, G.-S. Yang, J. T. Willerson, and Y.-J. Geng Combined Therapy With Simvastatin and Bone Marrow-Derived Mesenchymal Stem Cells Increases Benefits in Infarcted Swine Hearts Arterioscler Thromb Vasc Biol, December 1, 2009; 29(12): 2076 - 2082. [Abstract] [Full Text] [PDF]

				Z. Yang, D. Gagarin, G. St. Laurent III, N. Hammell, I. Toma, C.-a. Hu, A. Iwasa, and T. A. McCaffrey Cardiovascular Inflammation and Lesion Cell Apoptosis: A Novel Connection via the Interferon-Inducible Immunoproteasome Arterioscler Thromb Vasc Biol, August 1, 2009; 29(8): 1213 - 1219. [Abstract] [Full Text] [PDF]

				P. Libby Molecular and cellular mechanisms of the thrombotic complications of atherosclerosis J. Lipid Res., April 1, 2009; 50(Supplement): S352 - S357. [Abstract] [Full Text] [PDF]

				K.-L. Shi, B. He, J.-J. Wang, and L.-P. Zou Role of TNF-{alpha} Gene Variation in Idiopathic Childhood Ischemic Stroke: A Case-Control Study J Child Neurol, January 1, 2009; 24(1): 25 - 29. [Abstract] [PDF]

				M. M. Kavurma, N. Y. Tan, and M. R. Bennett Death Receptors and Their Ligands in Atherosclerosis Arterioscler Thromb Vasc Biol, October 1, 2008; 28(10): 1694 - 1702. [Abstract] [Full Text] [PDF]

				K. Maiellaro and W. R. Taylor The role of the adventitia in vascular inflammation Cardiovasc Res, September 1, 2007; 75(4): 640 - 648. [Abstract] [Full Text] [PDF]

				M.-J. Leroy, E. Dallot, I. Czerkiewicz, T. Schmitz, and M. Breuiller-Fouche Inflammation of Choriodecidua Induces Tumor Necrosis Factor Alpha-Mediated Apoptosis of Human Myometrial Cells Biol Reprod, May 1, 2007; 76(5): 769 - 776. [Abstract] [Full Text] [PDF]

				V. I. Patel, S. Daniel, C. R. Longo, G. V. Shrikhande, S. T. Scali, E. Czismadia, C. M. Groft, T. Shukri, C. Motley-Dore, H. E. Ramsey, et al. A20, a modulator of smooth muscle cell proliferation and apoptosis, prevents and induces regression of neointimal hyperplasia FASEB J, July 1, 2006; 20(9): 1418 - 1430. [Abstract] [Full Text] [PDF]

				A. Tedgui and Z. Mallat Cytokines in Atherosclerosis: Pathogenic and Regulatory Pathways Physiol Rev, April 1, 2006; 86(2): 515 - 581. [Abstract] [Full Text] [PDF]

				G. Aidinian, J. M. Weiswasser, S. Arora, C. J. Abularrage, N. Singh, and A. N. Sidawy Carotid Plaque Morphologic Characteristics Perspectives in Vascular Surgery and Endovascular Therapy, March 1, 2006; 18(1): 63 - 70. [Abstract] [PDF]

				M. Igata, H. Motoshima, K. Tsuruzoe, K. Kojima, T. Matsumura, T. Kondo, T. Taguchi, K. Nakamaru, M. Yano, D. Kukidome, et al. Adenosine Monophosphate-Activated Protein Kinase Suppresses Vascular Smooth Muscle Cell Proliferation Through the Inhibition of Cell Cycle Progression Circ. Res., October 14, 2005; 97(8): 837 - 844. [Abstract] [Full Text] [PDF]

				V. C. Mehra, V. S. Ramgolam, and J. R. Bender Cytokines and cardiovascular disease J. Leukoc. Biol., October 1, 2005; 78(4): 805 - 818. [Abstract] [Full Text] [PDF]

				G. J. Wang, X. X. Sui, H. F. Simosa, M. K. Jain, D. C. Altieri, and M. S. Conte Regulation of Vein Graft Hyperplasia by Survivin, an Inhibitor of Apoptosis Protein Arterioscler Thromb Vasc Biol, October 1, 2005; 25(10): 2081 - 2087. [Abstract] [Full Text] [PDF]

				A. Daugherty, N. R. Webb, D. L. Rateri, and V. L. King Thematic review series: The Immune System and Atherogenesis. Cytokine regulation of macrophage functions in atherogenesis J. Lipid Res., September 1, 2005; 46(9): 1812 - 1822. [Abstract] [Full Text] [PDF]

				E. J. Harvey and D. P. Ramji Interferon-{gamma} and atherosclerosis: Pro- or anti-atherogenic? Cardiovasc Res, July 1, 2005; 67(1): 11 - 20. [Abstract] [Full Text] [PDF]

				V. Tang, A. Dhirapong, A. P. Yabes, and R. H. Weiss TNF-{alpha}-mediated apoptosis in vascular smooth muscle cells requires p73 Am J Physiol Cell Physiol, July 1, 2005; 289(1): C199 - C206. [Abstract] [Full Text] [PDF]

				C. S. Moran, M. McCann, M. Karan, P. Norman, N. Ketheesan, and J. Golledge Association of Osteoprotegerin With Human Abdominal Aortic Aneurysm Progression Circulation, June 14, 2005; 111(23): 3119 - 3125. [Abstract] [Full Text] [PDF]

				R. Madonna, P. Di Napoli, M. Massaro, A. Grilli, M. Felaco, A. De Caterina, D. Tang, R. De Caterina, and Y.-J. Geng Simvastatin Attenuates Expression of Cytokine-inducible Nitric-oxide Synthase in Embryonic Cardiac Myoblasts J. Biol. Chem., April 8, 2005; 280(14): 13503 - 13511. [Abstract] [Full Text] [PDF]

				M. Vantler, E. Caglayan, W. H. Zimmermann, A. T. Baumer, and S. Rosenkranz Systematic Evaluation of Anti-apoptotic Growth Factor Signaling in Vascular Smooth Muscle Cells: ONLY PHOSPHATIDYLINOSITOL 3'-KINASE IS IMPORTANT J. Biol. Chem., April 8, 2005; 280(14): 14168 - 14176. [Abstract] [Full Text] [PDF]

				T. Nakazawa, T. Chiba, E. Kaneko, K. Yui, M. Yoshida, and K. Shimokado Insulin Signaling in Arteries Prevents Smooth Muscle Apoptosis Arterioscler Thromb Vasc Biol, April 1, 2005; 25(4): 760 - 765. [Abstract] [Full Text] [PDF]

				Z. Wang, P. J. Rao, M. R. Castresana, and W. H. Newman TNF-{alpha} induces proliferation or apoptosis in human saphenous vein smooth muscle cells depending on phenotype Am J Physiol Heart Circ Physiol, January 1, 2005; 288(1): H293 - H301. [Abstract] [Full Text] [PDF]

				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]

				R. Stocker and J. F. Keaney Jr. Role of Oxidative Modifications in Atherosclerosis Physiol Rev, October 1, 2004; 84(4): 1381 - 1478. [Abstract] [Full Text] [PDF]

				W. Wang, W. Sun, and X. Wang Intramuscular gene transfer of CGRP inhibits neointimal hyperplasia after balloon injury in the rat abdominal aorta Am J Physiol Heart Circ Physiol, October 1, 2004; 287(4): H1582 - H1589. [Abstract] [Full Text] [PDF]

				S. Ling, A. Dai, R. J. Dilley, M. Jones, E. Simpson, P. A. Komesaroff, and K. Sudhir Endogenous Estrogen Deficiency Reduces Proliferation and Enhances Apoptosis-Related Death in Vascular Smooth Muscle Cells: Insights From the Aromatase-Knockout Mouse Circulation, February 3, 2004; 109(4): 537 - 543. [Abstract] [Full Text] [PDF]

				J. Herrmann, A. Ciechanover, L. O Lerman, and A. Lerman The ubiquitin-proteasome system in cardiovascular diseases--a hypothesis extended Cardiovasc Res, January 1, 2004; 61(1): 11 - 21. [Abstract] [Full Text] [PDF]

				F. D. Kolodgie, A. Petrov, R. Virmani, N. Narula, J. W. Verjans, D. K. Weber, D. Hartung, N. Steinmetz, J. L. Vanderheyden, M. A. Vannan, et al. Targeting of Apoptotic Macrophages and Experimental Atheroma With Radiolabeled Annexin V: A Technique With Potential for Noninvasive Imaging of Vulnerable Plaque Circulation, December 23, 2003; 108(25): 3134 - 3139. [Abstract] [Full Text] [PDF]

				A. Gojova, V. Brun, B. Esposito, F. Cottrez, P. Gourdy, P. Ardouin, A. Tedgui, Z. Mallat, and H. Groux Specific abrogation of transforming growth factor-{beta} signaling in T cells alters atherosclerotic lesion size and composition in mice Blood, December 1, 2003; 102(12): 4052 - 4058. [Abstract] [Full Text] [PDF]

				B. OSTERUD and E. BJORKLID Role of Monocytes in Atherogenesis Physiol Rev, October 1, 2003; 83(4): 1069 - 1112. [Abstract] [Full Text] [PDF]

				J. J. Boyle, P. L. Weissberg, and M. R. Bennett Tumor Necrosis Factor-{alpha} Promotes Macrophage-Induced Vascular Smooth Muscle Cell Apoptosis by Direct and Autocrine Mechanisms Arterioscler Thromb Vasc Biol, September 1, 2003; 23(9): 1553 - 1558. [Abstract] [Full Text] [PDF]

				S. S Vasudevan, N. H.M Lopes, P. N Seshiah, T. Wang, C. B Marsh, D. J Kereiakes, C. Dong, and P. J Goldschmidt-Clermont Mac-1 and Fas activities are concurrently required for execution of smooth muscle cell death by M-CSF-stimulated macrophages Cardiovasc Res, September 1, 2003; 59(3): 723 - 733. [Abstract] [Full Text] [PDF]

				T. S. Absi, T. M. Sundt III, W. S. Tung, M. Moon, J. K. Lee, R. R. Damiano Jr, and R. W. Thompson Altered patterns of gene expression distinguishing ascending aortic aneurysms from abdominal aortic aneurysms: complementary DNA expression profiling in the molecular characterization of aortic disease J. Thorac. Cardiovasc. Surg., August 1, 2003; 126(2): 344 - 357. [Abstract] [Full Text] [PDF]

				D. A. Goukassian, R. Kishore, K. Krasinski, C. Dolan, C. Luedemann, Y.-s. Yoon, M. Kearney, A. Hanley, H. Ma, T. Asahara, et al. Engineering the Response to Vascular Injury: Divergent Effects of Deregulated E2F1 Expression on Vascular Smooth Muscle Cells and Endothelial Cells Result in Endothelial Recovery and Inhibition of Neointimal Growth Circ. Res., July 25, 2003; 93(2): 162 - 169. [Abstract] [Full Text] [PDF]

				C.J. Malkin, P.J. Pugh, T.H. Jones, and K.S. Channer Testosterone for secondary prevention in men with ischaemic heart disease? QJM, July 1, 2003; 96(7): 521 - 529. [Full Text] [PDF]

				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]

				S. Ueda, S. Kato, H. Matsuoka, M. Kimoto, S. Okuda, M. Morimatsu, and T. Imaizumi Regulation of Cytokine-Induced Nitric Oxide Synthesis by Asymmetric Dimethylarginine: Role of Dimethylarginine Dimethylaminohydrolase Circ. Res., February 7, 2003; 92(2): 226 - 233. [Abstract] [Full Text] [PDF]

				S. Idel, P. Ellinghaus, C. Wolfrum, J.-R. Nofer, J. Gloerich, G. Assmann, F. Spener, and U. Seedorf Branched Chain Fatty Acids Induce Nitric Oxide-dependent Apoptosis in Vascular Smooth Muscle Cells J. Biol. Chem., December 13, 2002; 277(51): 49319 - 49325. [Abstract] [Full Text] [PDF]

				S. Taurin, V. Seyrantepe, S. N. Orlov, T.-L. Tremblay, P. Thibault, M. R. Bennett, P. Hamet, and A. V. Pshezhetsky Proteome Analysis and Functional Expression Identify Mortalin as an Antiapoptotic Gene Induced by Elevation of [Na+]i/[K+]i Ratio in Cultured Vascular Smooth Muscle Cells Circ. Res., November 15, 2002; 91(10): 915 - 922. [Abstract] [Full Text] [PDF]

				Y.-J. Geng and P. Libby Progression of Atheroma: A Struggle Between Death and Procreation Arterioscler Thromb Vasc Biol, September 1, 2002; 22(9): 1370 - 1380. [Abstract] [Full Text] [PDF]

				G. K. Hansson, P. Libby, U. Schonbeck, and Z.-Q. Yan Innate and Adaptive Immunity in the Pathogenesis of Atherosclerosis Circ. Res., August 23, 2002; 91(4): 281 - 291. [Abstract] [Full Text] [PDF]

				R. M Smith, N. Suleman, J. McCarthy, and M. N Sack Classic ischemic but not pharmacologic preconditioning is abrogated following genetic ablation of the TNF{alpha} gene Cardiovasc Res, August 15, 2002; 55(3): 553 - 560. [Abstract] [Full Text] [PDF]

				W. Durante Carbon monoxide and bile pigments: surprising mediators of vascular function Vascular Medicine, August 1, 2002; 7(3): 195 - 202. [Abstract] [PDF]

				M. A. Zimmerman, C. H. Selzman, L. L. Reznikov, S. A. Miller, C. D. Raeburn, J. Emmick, X. Meng, and A. H. Harken Lack of TNF-alpha attenuates intimal hyperplasia after mouse carotid artery injury Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2002; 283(2): R505 - R512. [Abstract] [Full Text] [PDF]

				X.-m. Liu, G. B Chapman, K. J Peyton, A. I Schafer, and W. Durante Carbon monoxide inhibits apoptosis in vascular smooth muscle cells Cardiovasc Res, August 1, 2002; 55(2): 396 - 405. [Abstract] [Full Text] [PDF]

				I. Baranova, T. Vishnyakova, A. Bocharov, Z. Chen, A. T. Remaley, J. Stonik, T. L. Eggerman, and A. P. Patterson Lipopolysaccharide Down Regulates Both Scavenger Receptor B1 and ATP Binding Cassette Transporter A1 in RAW Cells Infect. Immun., June 1, 2002; 70(6): 2995 - 3003. [Abstract] [Full Text] [PDF]

				M. Sotoudeh, Y.-S. Li, N. Yajima, C.-C. Chang, T.-C. Tsou, Y. Wang, S. Usami, A. Ratcliffe, S. Chien, and J. Y.-J. Shyy Induction of apoptosis in vascular smooth muscle cells by mechanical stretch Am J Physiol Heart Circ Physiol, May 1, 2002; 282(5): H1709 - H1716. [Abstract] [Full Text] [PDF]

				S. C. Whitman, P. Ravisankar, and A. Daugherty Interleukin-18 Enhances Atherosclerosis in Apolipoprotein E-/- Mice Through Release of Interferon-{gamma} Circ. Res., February 8, 2002; 90 (2): e34 - e38. [Abstract] [Full Text] [PDF]

				M. S. Elkind, J. Cheng, B. Boden-Albala, T. Rundek, J. Thomas, H. Chen, L. E. Rabbani, R. L. Sacco, and A. G. Thrift Tumor Necrosis Factor Receptor Levels Are Associated With Carotid Atherosclerosis * Editorial Comment Stroke, January 1, 2002; 33(1): 31 - 38. [Abstract] [Full Text] [PDF]

				X.-m. Liu, G. B. Chapman, H. Wang, and W. Durante Adenovirus-Mediated Heme Oxygenase-1 Gene Expression Stimulates Apoptosis in Vascular Smooth Muscle Cells Circulation, January 1, 2002; 105(1): 79 - 84. [Abstract] [Full Text] [PDF]

				G. K. Hansson Immune Mechanisms in Atherosclerosis Arterioscler Thromb Vasc Biol, December 1, 2001; 21(12): 1876 - 1890. [Abstract] [Full Text] [PDF]

				A. Niemann-Jonsson, M. P.S. Ares, Z.-Q. Yan, D.-X. Bu, G. N. Fredrikson, L. Branen, I. Porn-Ares, A. H. Nilsson, and J. Nilsson Increased Rate of Apoptosis in Intimal Arterial Smooth Muscle Cells Through Endogenous Activation of TNF Receptors Arterioscler Thromb Vasc Biol, December 1, 2001; 21(12): 1909 - 1914. [Abstract] [Full Text] [PDF]

				M. Saio, S. Radoja, M. Marino, and A. B. Frey Tumor-Infiltrating Macrophages Induce Apoptosis in Activated CD8+ T Cells by a Mechanism Requiring Cell Contact and Mediated by Both the Cell-Associated Form of TNF and Nitric Oxide J. Immunol., November 15, 2001; 167(10): 5583 - 5593. [Abstract] [Full Text] [PDF]

				K. Krasinski, I. Spyridopoulos, M. Kearney, and D. W. Losordo In Vivo Blockade of Tumor Necrosis Factor-{alpha} Accelerates Functional Endothelial Recovery After Balloon Angioplasty Circulation, October 9, 2001; 104(15): 1754 - 1756. [Abstract] [Full Text] [PDF]

				J. J. Boyle, D. E. Bowyer, P. L. Weissberg, and M. R. Bennett Human Blood-Derived Macrophages Induce Apoptosis in Human Plaque-Derived Vascular Smooth Muscle Cells by Fas-Ligand/Fas Interactions Arterioscler Thromb Vasc Biol, September 1, 2001; 21(9): 1402 - 1407. [Abstract] [Full Text] [PDF]

				Q. Feng, X. Lu, D. L. Jones, J. Shen, and J. M. O. Arnold Increased Inducible Nitric Oxide Synthase Expression Contributes to Myocardial Dysfunction and Higher Mortality After Myocardial Infarction in Mice Circulation, August 7, 2001; 104(6): 700 - 704. [Abstract] [Full Text] [PDF]

				G. Valen, Z.-q. Yan, and G.o. K. Hansson Nuclear factor kappa-B and the heart J. Am. Coll. Cardiol., August 1, 2001; 38(2): 307 - 314. [Abstract] [Full Text] [PDF]

				Y. Aizawa, J.-i. Kawabe, N. Hasebe, N. Takehara, and K. Kikuchi Pioglitazone Enhances Cytokine-Induced Apoptosis in Vascular Smooth Muscle Cells and Reduces Intimal Hyperplasia Circulation, July 24, 2001; 104(4): 455 - 460. [Abstract] [Full Text] [PDF]

				C. H. Selzman, S. A. Miller, and A. H. Harken Therapeutic implications of inflammation in atherosclerotic cardiovascular disease Ann. Thorac. Surg., June 1, 2001; 71(6): 2066 - 2074. [Abstract] [Full Text] [PDF]

				G.K. Hansson The stabilized plaque: will the dream come true? Eur. Heart J. Suppl., June 1, 2001; 3(suppl_C): C69 - C75. [PDF]

				M. R. Bennett Reactive Oxygen Species and Death : Oxidative DNA Damage in Atherosclerosis Circ. Res., April 13, 2001; 88(7): 648 - 650. [Full Text] [PDF]

				P. Andreka, J. Zang, C. Dougherty, T. I. Slepak, K. A. Webster, and N. H. Bishopric Cytoprotection by Jun Kinase During Nitric Oxide-Induced Cardiac Myocyte Apoptosis Circ. Res., February 16, 2001; 88(3): 305 - 312. [Abstract] [Full Text] [PDF]

				T. E. McDonald, M. N. Grinman, C. M. Carthy, and K. R. Walley Endotoxin infusion in rats induces apoptotic and survival pathways in hearts Am J Physiol Heart Circ Physiol, November 1, 2000; 279(5): H2053 - H2061. [Abstract] [Full Text] [PDF]

				V. Hampl and J. Herget Role of Nitric Oxide in the Pathogenesis of Chronic Pulmonary Hypertension Physiol Rev, October 1, 2000; 80(4): 1337 - 1372. [Abstract] [Full Text] [PDF]

				H. Obara, A. Takayanagi, J. Hirahashi, K. Tanaka, G. Wakabayashi, K. Matsumoto, M. Shimazu, N. Shimizu, and M. Kitajima Overexpression of Truncated I{kappa}B{alpha} Induces TNF-{alpha}-Dependent Apoptosis in Human Vascular Smooth Muscle Cells Arterioscler Thromb Vasc Biol, October 1, 2000; 20(10): 2198 - 2204. [Abstract] [Full Text] [PDF]

				W. DURANTE, L. LIAO, S. V. REYNA, K. J. PEYTON, and A. I. SCHAFER Physiological cyclic stretch directs L-arginine transport and metabolism to collagen synthesis in vascular smooth muscle FASEB J, September 1, 2000; 14(12): 1775 - 1783. [Abstract] [Full Text]

				H.-S. Liao, T. Kodama, and Y.-J. Geng Expression of Class A Scavenger Receptor Inhibits Apoptosis of Macrophages Triggered by Oxidized Low Density Lipoprotein and Oxysterol Arterioscler Thromb Vasc Biol, August 1, 2000; 20(8): 1968 - 1975. [Abstract] [Full Text] [PDF]

				B. R. Gochuico, J. Zhang, B. Y. Ma, A. Marshak-Rothstein, and A. Fine TRAIL expression in vascular smooth muscle Am J Physiol Lung Cell Mol Physiol, May 1, 2000; 278(5): L1045 - L1050. [Abstract] [Full Text] [PDF]

				K. J. Hamann, J. E. Vieira, A. J. Halayko, D. Dorscheid, S. R. White, S. M. Forsythe, B. Camoretti-Mercado, K. F. Rabe, and J. Solway Fas cross-linking induces apoptosis in human airway smooth muscle cells Am J Physiol Lung Cell Mol Physiol, March 1, 2000; 278(3): L618 - L624. [Abstract] [Full Text] [PDF]

				G. B. Chapman, W. Durante, J. D. Hellums, and A. I. Schafer Physiological cyclic stretch causes cell cycle arrest in cultured vascular smooth muscle cells Am J Physiol Heart Circ Physiol, March 1, 2000; 278(3): H748 - H754. [Abstract] [Full Text] [PDF]

				M. Horiuchi, W. Hayashida, M. Akishita, S. Yamada, J. Y. A. Lehtonen, K. Tamura, L. Daviet, Y. E. Chen, M. Hamai, T.-X. Cui, et al. Interferon-{gamma} Induces AT2 Receptor Expression in Fibroblasts by Jak/STAT Pathway and Interferon Regulatory Factor-1 Circ. Res., February 4, 2000; 86(2): 233 - 240. [Abstract] [Full Text] [PDF]

				M. MAYR, C. LI, Y. ZOU, U. HUEMER, Y. HU, and Q. XU Biomechanical stress-induced apoptosis in vein grafts involves p38 mitogen-activated protein kinases FASEB J, February 1, 2000; 14(2): 261 - 270. [Abstract] [Full Text]

				M.-L. Peyot, A.-P. Gadeau, F. Dandre, I. Belloc, F. Dupuch, and C. Desgranges Extracellular Adenosine Induces Apoptosis of Human Arterial Smooth Muscle Cells via A2b-Purinoceptor Circ. Res., January 7, 2000; 86(1): 76 - 85. [Abstract] [Full Text] [PDF]

				T. Imanishi, J. McBride, Q. Ho, K. D. O達rien, S. M. Schwartz, and D. K. M. Han Expression of Cellular FLICE-Inhibitory Protein in Human Coronary Arteries and in a Rat Vascular Injury Model Am. J. Pathol., January 1, 2000; 156(1): 125 - 137. [Abstract] [Full Text] [PDF]

				J. Niebauer, S. P. Schwarzacher, M. Hayase, B. Wang, R. S. Kernoff, J. P. Cooke, and A. C. Yeung Local L-Arginine Delivery After Balloon Angioplasty Reduces Monocyte Binding and Induces Apoptosis Circulation, October 26, 1999; 100(17): 1830 - 1835. [Abstract] [Full Text] [PDF]

				J. Heckenkamp, D. Leszczynski, J. Schiereck, J. Kung, and G. M. LaMuraglia Different Effects of Photodynamic Therapy and {gamma}-Irradiation on Vascular Smooth Muscle Cells and Matrix : Implications for Inhibiting Restenosis Arterioscler Thromb Vasc Biol, September 1, 1999; 19(9): 2154 - 2161. [Abstract] [Full Text] [PDF]

				J. Ruef, A. S. Meshel, Z. Hu, C. Horaist, C. A. Ballinger, L. J. Thompson, V. D. Subbarao, J. A. Dumont, and C. Patterson Flavopiridol Inhibits Smooth Muscle Cell Proliferation In Vitro and Neointimal Formation In Vivo After Carotid Injury in the Rat Circulation, August 10, 1999; 100(6): 659 - 665. [Abstract] [Full Text] [PDF]

				L. J. Walton, I. J. Franklin, T. Bayston, L. C. Brown, R. M. Greenhalgh, G. W. Taylor, and J. T. Powell Inhibition of Prostaglandin E2 Synthesis in Abdominal Aortic Aneurysms : Implications for Smooth Muscle Cell Viability, Inflammatory Processes, and the Expansion of Abdominal Aortic Aneurysms Circulation, July 6, 1999; 100(1): 48 - 54. [Abstract] [Full Text] [PDF]

				J. Alcouffe, S. Caspar-Bauguil, V. Garcia, R. Salvayre, M. Thomsen, and H. Benoist Oxidized low density lipoproteins induce apoptosis in PHA-activated peripheral blood mononuclear cells and in the Jurkat T-cell line J. Lipid Res., July 1, 1999; 40(7): 1200 - 1210. [Abstract] [Full Text]

				G. K. Sukhova, U. Schonbeck, E. Rabkin, F. J. Schoen, A. R. Poole, R. C. Billinghurst, and P. Libby Evidence for Increased Collagenolysis by Interstitial Collagenases-1 and -3 in Vulnerable Human Atheromatous Plaques Circulation, May 18, 1999; 99(19): 2503 - 2509. [Abstract] [Full Text] [PDF]

				C. H. Selzman, B. D. Shames, L. L. Reznikov, S. A. Miller, X. Meng, H. A. Barton, A. Werman, A. H. Harken, C. A. Dinarello, and A. Banerjee Liposomal Delivery of Purified Inhibitory-{kappa}B{alpha} Inhibits Tumor Necrosis Factor-{alpha}蜂nduced Human Vascular Smooth Muscle Proliferation Circ. Res., April 30, 1999; 84(8): 867 - 875. [Abstract] [Full Text] [PDF]

				D. Bonderman, E. Gharehbaghi-Schnell, G. Wollenek, G. Maurer, H. Baumgartner, and I. M. Lang Mechanisms Underlying Aortic Dilatation in Congenital Aortic Valve Malformation Circulation, April 27, 1999; 99(16): 2138 - 2143. [Abstract] [Full Text] [PDF]

				J. Shindo, T. Ishibashi, K. Yokoyama, K. Nakazato, T. Ohwada, M. Shiomi, and Y. Maruyama Granulocyte-Macrophage Colony亡timulating Factor Prevents the Progression of Atherosclerosis via Changes in the Cellular and Extracellular Composition of Atherosclerotic Lesions in Watanabe Heritable Hyperlipidemic Rabbits Circulation, April 27, 1999; 99(16): 2150 - 2156. [Abstract] [Full Text] [PDF]

				W. Erl, G. K. Hansson, R. de Martin, G. Draude, K. S. C. Weber, and C. Weber Nuclear Factor-{kappa}B Regulates Induction of Apoptosis and Inhibitor of Apoptosis Protein-1 Expression in Vascular Smooth Muscle Cells Circ. Res., April 2, 1999; 84(6): 668 - 677. [Abstract] [Full Text] [PDF]

				B.-Y. Wang, H.-K. V. Ho, P. S. Lin, S. P. Schwarzacher, M. J. Pollman, G. H. Gibbons, P. S. Tsao, and J. P. Cooke Regression of Atherosclerosis : Role of Nitric Oxide and Apoptosis Circulation, March 9, 1999; 99(9): 1236 - 1241. [Abstract] [Full Text] [PDF]

				Z. Mallat, C. Heymes, J. Ohan, E. Faggin, G. Leseche, and A. Tedgui Expression of Interleukin-10 in Advanced Human Atherosclerotic Plaques : Relation to Inducible Nitric Oxide Synthase Expression and Cell Death Arterioscler Thromb Vasc Biol, March 1, 1999; 19(3): 611 - 616. [Abstract] [Full Text] [PDF]

				D. E. Gutstein and V. Fuster Pathophysiology and clinical significance of atherosclerotic plaque rupture Cardiovasc Res, February 1, 1999; 41(2): 323 - 333. [Abstract] [Full Text] [PDF]

				M. R Bennett Apoptosis of vascular smooth muscle cells in vascular remodelling and atherosclerotic plaque rupture Cardiovasc Res, February 1, 1999; 41(2): 361 - 368. [Abstract] [Full Text] [PDF]

				L. H Arroyo and R. T Lee Mechanisms of plaque rupture: mechanical and biologic interactions Cardiovasc Res, February 1, 1999; 41(2): 369 - 375. [Abstract] [Full Text] [PDF]

				R. Rabbani and E. J. Topol Strategies to achieve coronary arterial plaque stabilization Cardiovasc Res, February 1, 1999; 41(2): 402 - 417. [Abstract] [Full Text] [PDF]

				G. Bauriedel, R. Hutter, U. Welsch, R. Bach, H. Sievert, and B. Luderitz Role of smooth muscle cell death in advanced coronary primary lesions: implications for plaque instability Cardiovasc Res, February 1, 1999; 41(2): 480 - 488. [Abstract] [Full Text] [PDF]

				Z. Mallat, B. Hugel, J. Ohan, G. Leseche, J.-M. Freyssinet, and A. Tedgui Shed Membrane Microparticles With Procoagulant Potential in Human Atherosclerotic Plaques : A Role for Apoptosis in Plaque Thrombogenicity Circulation, January 26, 1999; 99(3): 348 - 353. [Abstract] [Full Text] [PDF]

				Y.-J. Geng, Y. Ishikawa, D. E. Vatner, T. E. Wagner, S. P. Bishop, S. F. Vatner, and C. J. Homcy Apoptosis of Cardiac Myocytes in Gs{alpha} Transgenic Mice Circ. Res., January 22, 1999; 84(1): 34 - 42. [Abstract] [Full Text] [PDF]

				T. K. Tarrant, P. B. Silver, J. L. Wahlsten, L. V. Rizzo, C.-C. Chan, B. Wiggert, and R. R. Caspi Interleukin 12 Protects from a T Helper Type 1-mediated Autoimmune Disease, Experimental Autoimmune Uveitis, through a Mechanism Involving Interferon {gamma}, Nitric Oxide, and Apoptosis J. Exp. Med., January 18, 1999; 189(2): 219 - 230. [Abstract] [Full Text] [PDF]

				E. L. Henderson, Y.-J. Geng, G. K. Sukhova, A. D. Whittemore, J. Knox, and P. Libby Death of Smooth Muscle Cells and Expression of Mediators of Apoptosis by T Lymphocytes in Human Abdominal Aortic Aneurysms Circulation, January 12, 1999; 99(1): 96 - 104. [Abstract] [Full Text] [PDF]

				A. Raisanen-Sokolowski, T. Glysing-Jensen, and M. E. Russell Leukocyte-Suppressing Influences of Interleukin (IL)-10 in Cardiac Allografts : Insights from IL-10 Knockout Mice Am. J. Pathol., November 1, 1998; 153(5): 1491 - 1500. [Abstract] [Full Text] [PDF]

				P. Libby The interface of atherosclerosis and thrombosis: basic mechanisms Vascular Medicine, August 1, 1998; 3(3): 225 - 229. [Abstract] [PDF]

				V. Poppa, J. K. Miyashiro, M. A. Corson, and B. C. Berk Endothelial NO Synthase Is Increased in Regenerating Endothelium After Denuding Injury of the Rat Aorta Arterioscler Thromb Vasc Biol, August 1, 1998; 18(8): 1312 - 1321. [Abstract] [Full Text] [PDF]

				J. K. Liao Endothelium and acute coronary syndromes Clin. Chem., August 1, 1998; 44(8): 1799 - 1808. [Abstract] [Full Text] [PDF]

				G. Bauriedel, S. Schluckebier, R. Hutter, U. Welsch, R. Kandolf, B. Luderitz, and M. F. Prescott Apoptosis in Restenosis Versus Stable-Angina Atherosclerosis : Implications for the Pathogenesis of Restenosis Arterioscler Thromb Vasc Biol, July 1, 1998; 18(7): 1132 - 1139. [Abstract] [Full Text] [PDF]

				M. D. Rekhter, R. D. Simari, C. W. Work, G. J. Nabel, E. G. Nabel, and D. Gordon Gene Transfer Into Normal and Atherosclerotic Human Blood Vessels Circ. Res., June 29, 1998; 82(12): 1243 - 1252. [Abstract] [Full Text] [PDF]

This Article Abstract Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Geng, Y.-J. Articles by Libby, P. Search for Related Content PubMed PubMed Citation Articles by Geng, Y.-J. Articles by Libby, P.