A20 inhibits post-angioplasty restenosis by blocking macrophage trafficking and decreasing adventitial neovascularization.
OBJECTIVE
Neointimal hyperplasia is an inflammatory and proliferative process that occurs as a result of injury to the vessel wall. We have shown that the homeostatic protein A20 prevents neointimal hyperplasia by affecting endothelial cell (EC) and smooth muscle cell (SMC) responses to injury. In this work, we questioned whether A20 impacts other pathogenic effectors of neointimal hyperplasia including homing of monocyte/macrophages and EC/SMC precursors to the site of vascular injury, vascular endothelial growth factor (VEGF) secretion, and adventitial neovascularization.


RESULTS
Carotid balloon angioplasty was performed on rat recipients of a bone marrow transplant from green fluorescent rats. Adenoviral delivery of A20 prevented neointimal hyperplasia and decreased macrophage infiltration. This was associated with decreased ICAM-1 and MCP-1 expression in vitro. Additionally, A20 reduced neovascularization in the adventitia of balloon injured carotid arteries, which correlated with fewer VEGF positive cells.


CONCLUSIONS
A20 downregulates adhesion markers, chemokine production, and adventitial angiogenesis, all of which are required for macrophage trafficking to sites of vascular injury. This, in turn, diminishes the inflammatory milieu to prevent neointimal hyperplasia.
Damrauer
Scott M
SM
The Division of Vascular Surgery, Department of Surgery and Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
Fisher
Mark D
MD
Wada
Hiromi
H
Siracuse
Jeffrey J
JJ
da Silva
Cleide G
CG
Moon
Karam
K
Csizmadia
Eva
E
Maccariello
Elizabeth R
ER
Patel
Virendra I
VI
Studer
Peter
P
Essayagh
Sanah
S
Aird
William C
WC
Daniel
Soizic
S
Ferran
Christiane
C
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002465:Cell Movement; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015536:Down-Regulation; D004730:Endothelium, Vascular / Q000473:pathology; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D008297:Male; D009000:Monocytes / Q000378:metabolism; D058426:Neointima / Q000473:pathology; D009389:Neovascularization, Pathologic; D009687:Nuclear Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D020298:U937 Cells; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D042461:Vascular Endothelial Growth Factor A; C076529:TNFAIP3 protein, human; C000602677:TNFAIP3 protein, rat; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3