(Circulation. 2000;101:2450.)
© 2000 American Heart Association, Inc.
Brief Rapid Communications |
From the Institut National de la Santé et de la Recherche Médicale, INSERM U541, Institut Fédératif de Recherche "Circulation," Hôpital Lariboisière, Paris, France (O.T., Z.M., C.H., A.T.); Service de Médecine Interne Gériatrique, Hôpital René Muret-Bigottini, Sevran, France (J.B.); and Service de chirurgie Thoracique et Vasculaire, Hôpital Beaujon, Clichy, France (G.L.).
Correspondence to Alain Tedgui, PhD, INSERM U541, Hôpital Lariboisière, 41 Bd de la Chapelle, 75010 Paris, France. E-mail tedgui{at}infobiogen.fr
| Abstract |
|---|
|
|
|---|
Methods and ResultsA total of 42 human carotid atherosclerotic
plaques were retrieved by endarterectomy; they were
examined in the longitudinal axial direction. Plaques were included in
this study when upstream and downstream parts were clearly visible,
occlusion was absent, and immunostaining for luminal
endothelium was present all along the plaque. Using
these criteria, 13 plaques were processed for further
immunohistochemical studies (using anti-CD31, anti-Ki-67, and
anti-splicing factor antibodies) and in situ detection of
apoptosis (terminal dUTP nick end-labeling and ligase assay).
Eight plaques showed
1 apoptotic endothelial
cell at the luminal surface. Quantitative analysis of
endothelial cell apoptosis in these plaques
showed a systematic preferential occurrence of apoptosis in the
downstream parts of plaques, where low flow and low shear stress
prevail, in comparison with the upstream parts (18.8±3.3% versus
2.7±1.2%, respectively, P<0.001).
Endothelial cell apoptosis was barely
detectable in plaque microvessels.
ConclusionsOur results suggest that in vivo local shear stress influences luminal endothelial cell apoptosis and may be a major determinant of plaque erosion and thrombosis.
Key Words: blood flow stress, mechanical atherosclerosis apoptosis endothelium
| Introduction |
|---|
|
|
|---|
Despite the major potential implications of endothelial cell apoptosis in atherosclerotic plaque development and stability, little is known about the occurrence of endothelial cell apoptosis in human atherosclerosis and its relation to blood flow. We used the carotid endarterectomy technique, which preserves the en bloc plaque structure, to investigate the occurrence and distribution of endothelial cell apoptosis in human plaques examined in the longitudinal axial direction, upstream and downstream from the stenosis, where shear stress varies dramatically.10 11
| Methods |
|---|
|
|
|---|
|
Adjacent sections were stained for endothelial cells with an antibody against CD31 (clone JC/70A, DAKO, dilution 1:20), for proliferation with an antibody against Ki-67 (clone ch.-B.:066[201], DAKO, dilution 1:100), and for RNA transcription with an antibody against "splicing factor" (clone SC-35, DAKO, dilution 1:100). Negative controls were performed with an irrelevant immunoglobulin.
In situ detection of apoptosis was performed using 2 different techniques: the TdT dUTP nick end-labeling (TUNEL) method and the in situ ligase assay.12 Negative controls were performed by omitting the enzyme TdT (for TUNEL) or the T4 DNA ligase (for the ligase assay); positive controls were performed by pretreating the sections with 10 U/mL DNase I for 20 minutes at 37°C.
An endothelial cell was considered apoptotic when the following criteria were fulfilled: positive immunostaining with anti-CD31 antibody, positive staining with the TUNEL technique, and negative immunostaining with anti-Ki-67 and anti-splicing factor antibodies. Luminal endothelial cells considered apoptotic were counted in the upstream and downstream parts of the plaques by an observer who was unaware of the blood flow direction. For each stain, 3 slides (3 tissue sections/slide) taken from different areas of the plaque were used for quantitative analysis.
The results are expressed as means±SEM. A paired Students t test was used to compare the differences between the upstream and downstream areas, and P<0.05 was considered statistically significant.
| Results |
|---|
|
|
|---|
1 apoptotic endothelial cell at the luminal
surface. Endothelial cell apoptosis in these
plaques showed a systematic preferential occurrence of
apoptosis in the downstream part of the plaque (Figure 2
|
|
Endothelial cell apoptosis was barely
detectable in plaque microvessels, whether located in the upstream or
downstream part of the plaque (Figure 3
).
Positive staining with anti-Ki-67 antibody was rarely observed in
luminal endothelial cells. No staining with
anti-splicing factor antibody was detected.
|
| Discussion |
|---|
|
|
|---|
Using carotid human atherosclerotic plaques, which are validated models to study interactions between low or oscillatory shear stress and atherosclerosis,10 11 we provide the first in vivo evidence that blood flow directly influences endothelial cell survival or apoptosis in human atherosclerosis. Luminal endothelial cell apoptosis was observed in 60% of the plaques examined. In these plaques, we found a 7-fold increase in endothelial cell apoptosis in the downstream parts of plaques, where low shear prevails,10 11 in comparison with the upstream parts. The absence of apoptosis in 5 of the 13 plaques might be accounted for by counter-regulatory mechanisms of apoptosis, differences in local hemodynamics, or a short window of apoptotic death.
The lack of previous studies (including ones from our group) showing endothelial cell apoptosis in atherosclerotic plaques may be due to the use of transverse tissue sections taken almost exclusively from the most stenotic area of the plaque instead of the use of longitudinal tissue sections that allow for the examination of the entire plaque. Despite the abundance of plaque microvessels in both upstream and downstream parts, all sections showing microvessels were free of apoptosis, regardless of their location. In addition, we found that, contrary to the results in luminal endothelial cells, apoptosis within the plaque was significantly higher in the upstream part than in the downstream part.16 Taken together, these findings indicate that luminal endothelial cell apoptosis does not reflect a general apoptotic process occurring downstream from maximal stenosis, but most likely depends on local blood flow hemodynamics.
Our results agree with previous in vitro studies showing that laminar shear stress protects endothelial cells from apoptotic death.4 17 18 Several mechanisms have been proposed to account for the antiapoptotic effects of laminar shear stress, including upregulation of superoxide dismutase19 and Akt-mediated activation of nitric oxide synthase, with subsequent inhibition of the caspase cascade.20
Our study suggests that relatively large areas of endothelial erosion may occur in the distal part of atherosclerotic plaques. Given the high procoagulant and proadhesive potentials of apoptotic endothelial cells and the propensity of denuded vessel segments to platelet aggregation and vasospasm, this may lead to lumen thrombosis favoring plaque progression or the occurrence of acute coronary syndromes. Recently, Farb et al21 identified superficial endothelial erosion without plaque rupture as an important predisposing substrate for lumen vessel thrombosis, acute coronary syndromes, and sudden death. Our results suggest that in vivo local shear stress influences luminal endothelial cell apoptosis and may be a major determinant of plaque erosion and thrombosis.
| Acknowledgments |
|---|
Received December 31, 1999; revision received April 7, 2000; accepted April 7, 2000.
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
G. Foteinos, Y. Hu, Q. Xiao, B. Metzler, and Q. Xu Rapid Endothelial Turnover in Atherosclerosis-Prone Areas Coincides With Stem Cell Repair in Apolipoprotein E-Deficient Mice Circulation, April 8, 2008; 117(14): 1856 - 1863. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. C. Berk Atheroprotective Signaling Mechanisms Activated by Steady Laminar Flow in Endothelial Cells Circulation, February 26, 2008; 117(8): 1082 - 1089. [Full Text] [PDF] |
||||
![]() |
H. M. Heikkila, S. Latti, M. J. Leskinen, J. K. Hakala, P. T. Kovanen, and K. A. Lindstedt Activated Mast Cells Induce Endothelial Cell Apoptosis by a Combined Action of Chymase and Tumor Necrosis Factor-{alpha} Arterioscler. Thromb. Vasc. Biol., February 1, 2008; 28(2): 309 - 314. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Lu, W. Jiang, J.-H. Yang, P.-Y. Chang, J. P. Walterscheid, H.-H. Chen, M. Marcelli, D. Tang, Y.-T. Lee, W. S.L. Liao, et al. Electronegative LDL Impairs Vascular Endothelial Cell Integrity in Diabetes by Disrupting Fibroblast Growth Factor 2 (FGF2) Autoregulation Diabetes, January 1, 2008; 57(1): 158 - 166. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. S. Chatzizisis, A. U. Coskun, M. Jonas, E. R. Edelman, C. L. Feldman, and P. H. Stone Role of Endothelial Shear Stress in the Natural History of Coronary Atherosclerosis and Vascular Remodeling: Molecular, Cellular, and Vascular Behavior J. Am. Coll. Cardiol., June 26, 2007; 49(25): 2379 - 2393. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. A. El Solh, M. E. Akinnusi, F. H. Baddoura, and C. R. Mankowski Endothelial Cell Apoptosis in Obstructive Sleep Apnea: A Link to Endothelial Dysfunction Am. J. Respir. Crit. Care Med., June 1, 2007; 175(11): 1186 - 1191. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. M. Boulanger, N. Amabile, A. P. Guerin, B. Pannier, A. S. Leroyer, Z. Mallat, C. Nguyen, A. Tedgui, and G. M. London In Vivo Shear Stress Determines Circulating Levels of Endothelial Microparticles in End-Stage Renal Disease Hypertension, April 1, 2007; 49(4): 902 - 908. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Segers, F. Helderman, C. Cheng, L. C.A. van Damme, D. Tempel, E. Boersma, P. W. Serruys, R. de Crom, A. F.W. van der Steen, P. Holvoet, et al. Gelatinolytic Activity in Atherosclerotic Plaques Is Highly Localized and Is Associated With Both Macrophages and Smooth Muscle Cells In Vivo Circulation, February 6, 2007; 115(5): 609 - 616. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Isobe, S. Tsimikas, J. Zhou, S. Fujimoto, M. Sarai, M. J. Branks, A. Fujimoto, L. Hofstra, C. P. Reutelingsperger, T. Murohara, et al. Noninvasive Imaging of Atherosclerotic Lesions in Apolipoprotein E-Deficient and Low-Density-Lipoprotein Receptor-Deficient Mice with Annexin A5 J. Nucl. Med., September 1, 2006; 47(9): 1497 - 1505. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Huddleson, N. Ahmad, and J. B. Lingrel Up-regulation of the KLF2 Transcription Factor by Fluid Shear Stress Requires Nucleolin J. Biol. Chem., June 2, 2006; 281(22): 15121 - 15128. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Pfrommer, W. Erl, and P. C. Weber Docosahexaenoic acid induces ciap1 mRNA and protects human endothelial cells from stress-induced apoptosis Am J Physiol Heart Circ Physiol, June 1, 2006; 290(6): H2178 - H2186. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Hasel, S. Durr, A. Bauer, R. Heydrich, S. Bruderlein, T. Tambi, U. Bhanot, and P. Moller Pathologically elevated cyclic hydrostatic pressure induces CD95-mediated apoptotic cell death in vascular endothelial cells Am J Physiol Cell Physiol, August 1, 2005; 289(2): C312 - C322. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Tanaka, M. Sata, D. Fukuda, Y. Suematsu, N. Motomura, S. Takamoto, Y. Hirata, and R. Nagai Age-Associated Aortic Stenosis in Apolipoprotein E-Deficient Mice J. Am. Coll. Cardiol., July 5, 2005; 46(1): 134 - 141. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. L. Hazen Myeloperoxidase and Plaque Vulnerability Arterioscler. Thromb. Vasc. Biol., July 1, 2004; 24(7): 1143 - 1146. [Full Text] [PDF] |
||||
![]() |
S. Sugiyama, K. Kugiyama, M. Aikawa, S. Nakamura, H. Ogawa, and P. Libby Hypochlorous Acid, a Macrophage Product, Induces Endothelial Apoptosis and Tissue Factor Expression: Involvement of Myeloperoxidase-Mediated Oxidant in Plaque Erosion and Thrombogenesis Arterioscler. Thromb. Vasc. Biol., July 1, 2004; 24(7): 1309 - 1314. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Suhara, K. Fukuo, O. Yasuda, M. Tsubakimoto, Y. Takemura, H. Kawamoto, T. Yokoi, M. Mogi, T. Kaimoto, and T. Ogihara Homocysteine Enhances Endothelial Apoptosis via Upregulation of Fas-Mediated Pathways Hypertension, June 1, 2004; 43(6): 1208 - 1213. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Durand, A. Scoazec, A. Lafont, J. Boddaert, A. Al Hajzen, F. Addad, M. Mirshahi, M. Desnos, A. Tedgui, and Z. Mallat In Vivo Induction of Endothelial Apoptosis Leads to Vessel Thrombosis and Endothelial Denudation: A Clue to the Understanding of the Mechanisms of Thrombotic Plaque Erosion Circulation, June 1, 2004; 109(21): 2503 - 2506. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Stefanec Endothelial apoptosis: the missing link between atherosclerosis and SLE? Blood, May 15, 2004; 103(10): 3608 - 3609. [Full Text] [PDF] |
||||
![]() |
X. Pi, C. Yan, and B. C. Berk Big Mitogen-Activated Protein Kinase (BMK1)/ERK5 Protects Endothelial Cells From Apoptosis Circ. Res., February 20, 2004; 94(3): 362 - 369. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M Wasserman and J. N Topper Adaptation of the endothelium to fluid flow: in vitro analyses of gene expression and in vivo implications Vascular Medicine, February 1, 2004; 9(1): 35 - 45. [Abstract] [PDF] |
||||
![]() |
K. Nuotio, P. J. Lindsberg, O. Carpen, L. Soinne, E. M.P. Lehtonen-Smeds, E. Saimanen, R. Lassila, T. Sairanen, S. Sarna, O. Salonen, et al. Adhesion molecule expression in symptomatic and asymptomatic carotid stenosis Neurology, June 24, 2003; 60(12): 1890 - 1899. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Belton and D. Fitzgerald Cyclooxygenase-2 inhibitors and atherosclerosis J. Am. Coll. Cardiol., May 21, 2003; 41(10): 1820 - 1822. [Full Text] [PDF] |
||||
![]() |
D. L. Fry Arterial intimal-medial permeability and coevolving structural responses to defined shear-stress exposures Am J Physiol Heart Circ Physiol, December 1, 2002; 283(6): H2341 - H2355. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Y.-J. Shyy and S. Chien Role of Integrins in Endothelial Mechanosensing of Shear Stress Circ. Res., November 1, 2002; 91(9): 769 - 775. [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] |
||||
![]() |
C. Urbich, E. Dernbach, A. Aicher, A. M. Zeiher, and S. Dimmeler CD40 Ligand Inhibits Endothelial Cell Migration by Increasing Production of Endothelial Reactive Oxygen Species Circulation, August 20, 2002; 106(8): 981 - 986. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Durand, Z. Mallat, F. Addad, F. Vilde, M. Desnos, C. Guerot, A. Tedgui, and A. Lafont Time courses of apoptosis and cell proliferation and their relationship to arterial remodeling and restenosis after angioplasty in an atherosclerotic rabbit model J. Am. Coll. Cardiol., May 15, 2002; 39(10): 1680 - 1685. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. C. Boo, G. Sorescu, N. Boyd, I. Shiojima, K. Walsh, J. Du, and H. Jo Shear Stress Stimulates Phosphorylation of Endothelial Nitric-oxide Synthase at Ser1179 by Akt-independent Mechanisms. ROLE OF PROTEIN KINASE A J. Biol. Chem., January 25, 2002; 277(5): 3388 - 3396. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Mallat and A. Tedgui Current Perspective on the Role of Apoptosis in Atherothrombotic Disease Circ. Res., May 25, 2001; 88(10): 998 - 1003. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Sudoh, K. Toba, M. Akishita, J. Ako, M. Hashimoto, K. Iijima, S. Kim, Y.-Q. Liang, Y. Ohike, T. Watanabe, et al. Estrogen Prevents Oxidative Stress-Induced Endothelial Cell Apoptosis in Rats Circulation, February 6, 2001; 103(5): 724 - 729. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Dimmeler and A. M. Zeiher Endothelial Cell Apoptosis in Angiogenesis and Vessel Regression Circ. Res., September 15, 2000; 87(6): 434 - 439. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Chen, J. A. Vita, B. C. Berk, and J. F. Keaney Jr. c-Jun N-terminal Kinase Activation by Hydrogen Peroxide in Endothelial Cells Involves Src-dependent Epidermal Growth Factor Receptor Transactivation J. Biol. Chem., May 4, 2001; 276(19): 16045 - 16050. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-R. Nofer, B. Levkau, I. Wolinska, R. Junker, M. Fobker, A. von Eckardstein, U. Seedorf, and G. Assmann Suppression of Endothelial Cell Apoptosis by High Density Lipoproteins (HDL) and HDL-associated Lysosphingolipids J. Biol. Chem., September 7, 2001; 276(37): 34480 - 34485. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Hoffmann, J. Haendeler, A. Aicher, L. Rossig, M. Vasa, A. M. Zeiher, and S. Dimmeler Aging Enhances the Sensitivity of Endothelial Cells Toward Apoptotic Stimuli: Important Role of Nitric Oxide Circ. Res., October 12, 2001; 89(8): 709 - 715. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||