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(Circulation. 2004;110:2216-2219.)
© 2004 American Heart Association, Inc.
Vascular Medicine |


From the Vascular Research Laboratory (J.L.M.-V., L.M.B.-C., S.H.-M., J.E.), Department of Immunology (M.C.D., F.V.), and Department of Cardiology Fundación Jiménez Díaz (J.T.), Autónoma University, Madrid, Spain; U460 INSERM, Cardiovascular Remodeling, CHU X-Bichat, Paris, France (O.M., A.L., J.-B.M); the Protein Research Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark (O.N.J.); and the Proteomic Unit, Complutense University, Madrid, Spain (F.V.).
Correspondence to Professor Jesús Egido, MD, Vascular Research Laboratory, Fundación Jiménez Díaz, Avenida Reyes Católicos 2, 28040, Madrid, Spain. E-mail jegido{at}fjd.es
Received December 17, 2003; de novo received April 22, 2004; revision received May 26, 2004; accepted May 28, 2004.
| Abstract |
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Methods and Results Normal endartery segments and different regions of endarterectomy pieces (noncomplicated/complicated plaques) were incubated in protein-free medium, and the released proteins were analyzed by 2D electrophoresis (2-DE). Among the differently secreted proteins, we have identified heat shock protein-27 (HSP27). Surprisingly, compared with control arteries, HSP27 release was drastically decreased in atherosclerotic plaques and barely detectable in complicated plaque supernatants. HSP27 was expressed primarily by intact vascular cells of normal arteries and carotid plaques (immunohistochemistry). Plasma detection of soluble HSP27 showed that circulating HSP27 levels are significantly decreased in the blood of patients with carotid stenosis relative to healthy subjects (0.19 [0.1 to 1.95] versus 83 [71.8 to 87.8]) ng/mL, P<0.0001).
Conclusions HSP27 secretion is decreased in complicated atherosclerotic plaques, and sHSP27 plasma levels are decreased in atherosclerotic patients compared with healthy subjects. Plasma sHSP27 levels could be a potential index of atherosclerosis, although further validation is needed in large patient cohorts.
Key Words: plasma cells muscle, smooth electrophoresis
| Introduction |
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| Methods |
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Tissue Culture
Carotid endarterectomy samples were dissected as described previously,4 separating the stenosing complicated zone (origin of the internal carotid artery) from the adjacent plaque (common and external carotid endartery). Histological analysis showed that complicated plaques had ruptured and contained an intraplaque hemorrhage with a variable but important proportion of inflammatory cells. The adjacent area, considered noncomplicated plaque, was composed of fibrous thickening with a variable content of vascular smooth muscle cells (VSMCs). Femoral endarterectomies exhibited a high degree of calcification but no intraplaque hemorrhage. For mammary and radial arteries, the adventitia was removed before incubation of the intima-media. Samples were cut and incubated separately for 24 hours in serum-free RPMI medium at 37°C. Conditioned media were collected and centrifuged, and protein concentration was determined by Bradfords method. Tissue secretion attributed to necrosis during the incubation period was <10% as assessed by LDH release.
Proteomic Analysis
Conditioned media (600 µg of protein) were precipitated by use of 10% trichloroacetic acid in acetone with 0.07% 2-mercaptoethanol (1 hour, 20°C) and washed with cold acetone (20°C, 20 minutes) before 2-DE was performed. The spots of interest were treated as described previously.4 The peptides were analyzed in a Voyager DE STR MALDI-TOF mass spectrometer (Perspective Biosystem). Proteins were identified by use of the MASCOT program and comparing with SWISS-PROT and NCBI protein sequence databases. Phosphopeptides were characterized by liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS) and by immobilized metal affinity chromatography (IMAC)5 combined with MALDI Q-TOF MS/MS.6
Western Blot
Equal amounts of conditioned-medium proteins (15 µg) were loaded into a 12% polyacrylamide gel and electrophoresed as described previously.7 Blots were incubated with anti-HSP27 (sc-9012, Santa Cruz), anti-HSP60 (sc-1052), and anti-HSP70 (SPA-812 Stressgen) antibodies.
ELISA
Plasma and tissue conditioned media levels of soluble HSP27 (sHSP27) were measured with a commercially available kit (Oncogene).
Immunohistochemistry
Specimens were fixed with paraformaldehyde and embedded in paraffin, and immunohistochemistry was performed on 4-µm sections as described previously7 using polyclonal goat anti-human HSP27 antibody (sc-1049) and antiSMC-
-actin (clone 1A4, Dako).
Statistical Analysis
Statistical analysis was performed with SPSS 8.0. ELISA data are expressed as medians and interquartile ranges and were analyzed by the Mann-Whitney test. Differences between noncomplicated and complicated plaques were analyzed by Wilcoxon paired test.
| Results |
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Western blot analysis showed that HSP27 secretion is lower in atherosclerotic plaques (femoral, F; carotid noncomplicated plaques, NCP; carotid complicated plaques, CP) compared with control arteries (mammary, M; radial, R) (Figure 1, C and D). These data were confirmed by quantitative ELISA: M, 1243 (7341909); R, 910 (5052508); F, 303 (138-526); NCP, 315 (119-515); CP, 33 (17-111) (Figure 1D). We tested the secretion of other HSPs and found a diminished sHSP70 level in atherosclerotic samples, whereas sHSP60 showed the opposite pattern (Figure 1C). Whereas HSP60/70 exhibited a diffuse trend, diminished HSP27 release was clearly correlated to the complexity of the plaque.
Plasma HSP27 Is Decreased in Atherosclerotic Patients Relative to Healthy Subjects
To confirm our hypothesis that plasma protein content can reflect arterial wall secretion, we measured sHSP27 level in the plasma of patients with carotid stenosis and healthy controls. Circulating HSP27 levels were decreased 20-fold in patients with carotid atherosclerosis relative to healthy subjects (0.19 [0.1 to 1.95] versus 83 [71.8 to 87.8] ng/mL, P<0.0001) (Figure 1D).
Tissue HSP27 Immunostaining
By immunohistochemistry, we found that both human atherosclerotic plaques and mammary arteries expressed HSP27 protein. Immunostaining for HSP27 (Figure 2, A and C) and SMC-
-actin (B and D) in serial tissue sections showed that HSP27 was expressed primarily by VSMCs.8 No staining was obtained in negative controls (not shown).
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| Discussion |
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HSPs are ubiquitous proteins serving as molecular chaperones, and their cytoprotective functions rely on intracellular mechanisms. HSPs can also be secreted and released into the bloodstream, where their role in this soluble form remains unknown. In cardiovascular diseases, HSP expression is modulated both at the lesion site and in plasma.912 HSP70 has been suggested to protect VSMCs from oxidative aggression.13 Furthermore, increased levels of sHSP70 have been correlated with decreased intima/media thickness11 and with low risk of coronary artery disease.14 HSP60 was detected in aorta and carotid arteries, correlating with atherosclerosis severity.15 Moreover, sHSP60 could be a marker of atherosclerosis.9,10 To the best of our knowledge, nothing has yet been reported on HSP27 in atherosclerosis. HSP27 is expressed by both endothelial cells and VSMCs and is able, in its phosphorylated form, to bind and stabilize actin microfilaments, favoring the formation of actin stress fibers.16 We have shown that HSP27 colocalizes with VSMCs in human atherosclerotic plaques and mammary arteries, probably as a physiological response to hemodynamic or biomechanical stress. Indeed, hemodynamic stress increases the expression of HSP27 in VSMCs.8 Pharmacological induction of HSP27 attenuates intimal hyperplasia in vivo.17 HSP27 could also interfere with the atherosclerotic inflammatory response by inhibiting nuclear factor-
B activation.18 Finally, HSP27 can downregulate the apoptotic signaling pathway19 and could thus contribute to stabilize atherosclerotic lesions. We show for the first time that HSP27 is secreted by the undiseased vascular wall and that its release markedly diminishes according to the complexity of the plaque. Although this differential secretion does not seem to be specific for a vascular territory, because both mammary and radial endarteries secrete a higher amount of HSP27 than carotid or femoral atherosclerotic endarterectomies, this possibility cannot be excluded. Moreover, whereas sHSP27 is detected in the blood of 100% of healthy individuals, sHSP27 levels were almost undetectable in a large number of atherosclerotic patients. Despite a limited number of patients analyzed in this study, the marked statistical significance confers considerable value to our findings.
The cause and the biological significance of this important diminution of plasma HSP27 in atherosclerotic patients remain to be elucidated. Whether soluble HSP27 has an atheroprotective role or whether it is the reflection of a pathological vascular remodeling process is not known and requires further investigation. Our results strongly suggest that low levels of plasma HSP27 could serve as a potential marker for atherosclerosis and should be validated in larger cohorts.
| Acknowledgments |
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Disclosure
The authors are named as coinventors on pending patents filed by the Fundaicion Jimenez Diaz that relate to the use of biomarkers on cardiovascular disease.
| Footnotes |
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The last 2 authors contributed equally to this work. ![]()
| References |
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2. Bisoendial RJ, Hovingh GK, de Groot E, et al. Measurement of subclinical atherosclerosis: beyond risk factor assessment. Curr Opin Lipidol. 2002; 13: 595603.[CrossRef][Medline] [Order article via Infotrieve]
3. Naghavi M, Libby P, Falk E, et al. From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies, I. Circulation. 2003; 108: 16641672.
4. Duran MC, Mas S, Martin-Ventura JL, et al. Proteomic analysis of human vessels: application to atherosclerotic plaques. Proteomics. 2003; 3: 973978.[CrossRef][Medline] [Order article via Infotrieve]
5. Stensballe A, Andersen S, Jensen ON. Characterization of phosphoproteins from electrophoretic gels by nanoscale Fe(III) affinity chromatography with off-line mass spectrometry analysis. Proteomics. 2001; 1: 207222.[CrossRef][Medline] [Order article via Infotrieve]
6. Bennett KL, Stensballe A, Podtelejnikov AV, et al. Phosphopeptide detection and sequencing by matrix-assisted laser desorption/ionization quadrupole time-of-flight tandem mass spectrometry. J Mass Spectrom. 2002; 37: 179190.[CrossRef][Medline] [Order article via Infotrieve]
7. Blanco-Colio LM, Munoz-Garcia B, Martin-Ventura JL, et al. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors decrease Fas ligand expression and cytotoxicity in activated human T lymphocytes. Circulation. 2003; 108: 15061513.
8. McGregor E, Kempster L, Wait R, et al. F-actin capping (CapZ) and other contractile saphenous vein smooth muscle proteins are altered by hemodynamic stress: a proteomic approach. Mol Cell Proteomics. 2004; 3: 115124.
9. Pockley AG, Wu R, Lemne C, et al. Circulating HSP60 is associated with early cardiovascular disease. Hypertension. 2000; 36: 303307.
10. Xu Q, Schett G, Perschinka H, et al. Serum soluble HSP60 is elevated in subjects with atherosclerosis in a general population. Circulation. 2000; 102: 1420.
11. Pockley AG, Georgiades A, Thulin T, et al. Serum HSP70 levels predict the development of atherosclerosis in subjects with established hypertension. Hypertension. 2003; 42: 235238.
12. Pockley AG. Heat shock proteins, inflammation, and cardiovascular disease. Circulation. 2002; 105: 10121017.
13. Johnson AD, Berberian PA, Tytell M, et al. Differential distribution of 70-kD heat shock protein in atherosclerosis: its potential role in arterial SMC survival. Arterioscler Thromb Vasc Biol. 1995; 15: 2736.
14. Zhu J, Quyyumi AA, Wu H, et al. Increased serum levels of heat shock protein 70 are associated with low risk of coronary artery disease. Arterioscler Thromb Vasc Biol. 2003; 23: 10551059.
15. Kleindienst R, Xu Q, Willeit J, et al. Immunology of atherosclerosis: demonstration of HSP60 expression and T-lymphocytes bearing alpha/beta or gamma/delta receptor in human atherosclerotic lesions. Am J Pathol. 1993; 142: 19271937.[Abstract]
16. Bitar KN. HSP27 phosphorylation and interaction with actin-myosin in smooth muscle contraction. Am J Physiol. 2002; 282: G894G903.
17. Connolly EM, Kelly CJ, Chen G, et al. Pharmacological induction of HSP27 attenuates intimal hyperplasia in vivo. Eur J Vasc Endovasc Surg. 2003; 25: 4047.[CrossRef][Medline] [Order article via Infotrieve]
18. Park KJ, Gaynor RB, Kwak YT. HSP27 association with the I kappa B kinase complex regulates tumor necrosis factor alpha-induced NF-kB activation. J Biol Chem. 2003; 278: 3527235278.
19. Garrido C, Gurbuxani S, Ravagnan L, et al. Heat shock proteins: endogenous modulators of apoptotic cell death. Biochem Biophys Res Commun. 2001; 286: 433442.[CrossRef][Medline] [Order article via Infotrieve]
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