PRECLINICAL STUDY
Selective Clearance of Macrophages in Atherosclerotic Plaques by Autophagy
Stefan Verheye, MD, PhD*,*,
Wim Martinet, PhD ,
Mark M. Kockx, MD, PhD, ,
Michiel W.M. Knaapen, PhD ,
Koen Salu, MD, PhD,
Jean-Pierre Timmermans, PhD||,
Jeffrey T. Ellis, PhD¶,
Deborah L. Kilpatrick, PhD¶ and
Guido R.Y. De Meyer, PharMD, PhD
* Antwerp Cardiovascular Institute Middelheim, Antwerp, Belgium
Division of Pharmacology, University of Antwerp, Antwerp, Belgium
Department of Pathology, Middelheim Hospital, Antwerp, Belgium
Histogenex, Edegem, Belgium
|| Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
¶ Guidant Corporation, Santa Clara, California
Manuscript received August 21, 2006;
revised manuscript received September 26, 2006,
accepted September 28, 2006.
* Reprint requests and correspondence: Dr. Stefan Verheye, Antwerp Cardiovascular Institute, Middelheim Hospital, Lindendreef 1, 2020 Antwerp, Belgium. (Email: stefan.verheye{at}pandora.be).
Objectives: The purpose of this study was to investigate whether stent-based delivery of an inhibitor of mammalian target of rapamycin (mTOR) can selectively clear macrophages in rabbit atherosclerotic plaques.
Background: Current pharmacologic approaches to stabilize atherosclerotic plaques have only partially reduced the incidence of acute coronary syndromes and sudden death. Macrophages play a pivotal role in plaque destabilization, whereas smooth muscle cells (SMC) promote plaque stability.
Methods: Stents eluting the mTOR inhibitor everolimus were implanted in atherosclerotic arteries of cholesterol-fed rabbits. In addition, in vitro experiments using explanted atherosclerotic segments and cultured macrophages as well as SMC were performed.
Results: Stents eluting everolimus led to a marked reduction in macrophage content without altering the amount of SMC compared with polymer control stents. In vitro studies showed that everolimus treatment induced inhibition of translation in both cultured macrophages and SMC. However, cell death occurred only in macrophages and was characterized by bulk degradation of long-lived proteins, processing of microtubule-associated protein light chain 3, and cytoplasmic vacuolization, which are all markers of autophagy. Everolimus-induced autophagy was mediated by mTOR inhibition, because cell viability was not affected using tacrolimus, an mTOR-independent everolimus analog. Moreover, mTOR gene silencing was associated with selective induction of macrophage cell death. Autophagic macrophage cell death was confirmed by transmission electron microscopy both in cultured cells and in atherosclerotic explants.
Conclusions: Stent-based delivery of everolimus selectively cleared macrophages in rabbit atherosclerotic plaques by autophagy, an mTOR inhibition-dependent and novel mechanism to induce cell death in mammalian cells.
|
Abbreviations and Acronyms
| | 4E-BP1 = 4E-binding protein 1 | | eEF2 = eukaryotic elongation factor 2 | eIF2 = eukaryotic initiation factor 2 alpha | | FKBP12 = FK506-binding protein 12 | | LC-3 = microtubule-associated protein light chain 3 | | mTOR = mammalian target of rapamycin | | SMC = smooth muscle cells |
|
This article has been cited by other articles:
|
|
|
|
 
P. W. Serruys, H. M. Garcia-Garcia, and Y. Onuma
From metallic cages to transient bioresorbable scaffolds: change in paradigm of coronary revascularization in the upcoming decade?
Eur. Heart J.,
January 1, 2012;
33(1):
16 - 25.
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. M. Schrijvers, G. R. Y. De Meyer, and W. Martinet
Autophagy in Atherosclerosis: A Potential Drug Target for Plaque Stabilization
Arterioscler Thromb Vasc Biol,
December 1, 2011;
31(12):
2787 - 2791.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Onuma and P. W. Serruys
Bioresorbable Scaffold: The Advent of a New Era in Percutaneous Coronary and Peripheral Revascularization?
Circulation,
February 22, 2011;
123(7):
779 - 797.
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. Nakazawa, M. Nakano, F. Otsuka, J. N. Wilcox, R. Melder, S. Pruitt, F. D. Kolodgie, and R. Virmani
Evaluation of Polymer-Based Comparator Drug-Eluting Stents Using a Rabbit Model of Iliac Artery Atherosclerosis
Circ Cardiovasc Interv,
February 1, 2011;
4(1):
38 - 46.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Xu, Y. Yang, M. Yan, J. Zhan, X. Fu, and X. Zheng
Autophagy plays a protective role in free cholesterol overload-induced death of smooth muscle cells
J. Lipid Res.,
September 1, 2010;
51(9):
2581 - 2590.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. W. Ryter, S.-J. Lee, A. Smith, and A. M. K. Choi
Autophagy in Vascular Disease
Proceedings of the ATS,
February 15, 2010;
7(1):
40 - 47.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. L. Van Herck, G. R.Y. De Meyer, W. Martinet, C. E. Van Hove, K. Foubert, M. H. Theunis, S. Apers, H. Bult, C. J. Vrints, and A. G. Herman
Impaired Fibrillin-1 Function Promotes Features of Plaque Instability in Apolipoprotein E-Deficient Mice
Circulation,
December 15, 2009;
120(24):
2478 - 2487.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Semsroth, R. G. Stigler, O. Y. Bernecker, E. Ruttmann-Ulmer, J. Troppmair, K. Macfelda, J. O. Bonatti, and G. Laufer
Everolimus attenuates neointimal hyperplasia in cultured human saphenous vein grafts
Eur J Cardiothorac Surg,
March 1, 2009;
35(3):
515 - 520.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. Yamada, K. Ichimura, M. Kanekatsu, and W. G. van Doorn
Homologs of Genes Associated with Programmed Cell Death in Animal Cells are Differentially Expressed During Senescence of Ipomoea nil Petals
Plant Cell Physiol.,
March 1, 2009;
50(3):
610 - 625.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. Martinet and G. R.Y. De Meyer
Autophagy in Atherosclerosis: A Cell Survival and Death Phenomenon With Therapeutic Potential
Circ. Res.,
February 13, 2009;
104(3):
304 - 317.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Windecker and P. Juni
The Drug-Eluting Stent Saga
Circulation,
February 10, 2009;
119(5):
653 - 656.
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. Baetta, A. Granata, M. Canavesi, N. Ferri, L. Arnaboldi, S. Bellosta, P. Pfister, and A. Corsini
Everolimus Inhibits Monocyte/Macrophage Migration in Vitro and Their Accumulation in Carotid Lesions of Cholesterol-Fed Rabbits
J. Pharmacol. Exp. Ther.,
February 1, 2009;
328(2):
419 - 425.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
V. Croons, W. Martinet, A. G. Herman, and G. R. Y. De Meyer
Differential Effect of the Protein Synthesis Inhibitors Puromycin and Cycloheximide on Vascular Smooth Muscle Cell Viability
J. Pharmacol. Exp. Ther.,
June 1, 2008;
325(3):
824 - 832.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Cui, Y. Huang, Y. Zhao, and J. Zheng
Transcription Factor FOXO3a Mediates Apoptosis in HIV-1-Infected Macrophages
J. Immunol.,
January 15, 2008;
180(2):
898 - 906.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. Martinet and G. R.Y. De Meyer
Selective Depletion of Macrophages in Atherosclerotic Plaques: Myth, Hype, or Reality?
Circ. Res.,
March 30, 2007;
100(6):
751 - 753.
[Full Text]
[PDF]
|
|
|
|
