| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molecular Medicine |

From the Department of Medicine, Division of Cardiovascular Research (D.A.G., R.K., K.K., C.D., C.L., Y.-s.Y., M.K., A.H., H.M., T.A., J.M.I., D.W.L.), St Elizabeths Medical Center, Boston, Mass; and the Department of Dermatology (D.A.G.), Boston University School of Medicine, Boston, Mass.
Correspondence to Douglas W. Losordo, MD, Division of Cardiovascular Medicine, St Elizabeths Medical Center, 736 Cambridge St, Boston, MA 02135. E-mail douglas.losordo{at}tufts.edu
Tumor necrosis factor-
(TNF-
) is expressed locally in the vessel wall after angioplasty and induces growth arrest and apoptosis in endothelial cells (ECs), thereby delaying reendothelialization. Prior studies have shown that direct antagonism of TNF-
, using a systemically administered soluble receptor, can enhance endothelial recovery and reduce neointimal thickening. These studies have also shown that downregulation of the transcription factor E2F1 was a key mechanism of TNFs effect on ECs. We now show that Ad-E2F1 overexpression at sites of balloon injury accelerates functional endothelial recovery, consistent with the prior in vitro findings. Moreover these studies also reveal divergent effects of TNF-
and overexpression of E2F1 on ECs versus VSMCs. TNF-
exposure of VSMCs had no affect on proliferation or apoptosis, in contrast to the effect seen in ECs. In Ad-E2F1-transduced VSMCs, however, TNF-
-induced marked apoptosis in contrast to the survival effect seen in ECs. Finally, these studies suggest that differential activation of NF-
B may play a key role in mediating these opposing effects. Nuclear translocation and transcriptional activity of NF-
B was markedly attenuated in Ad-E2F1-transduced VSMCs, whereas it remained active in similarly treated ECs when the cells were exposed to TNF-
. These studies reveal that overexpression of Ad-E2F1 primes VSMCs to TNF-
-induced apoptosis. Furthermore, E2F1 potentiates VSMC death by blocking antiapoptotic signaling pathway through inhibition of NF-
B activation. The divergent responses of VSMCs and ECs to E2F1 overexpression provide unique therapeutic possibilities: simultaneously targeting the cell cycle of two different cell types, within same tissue microenvironment resulting in opposite and biologically complimentary effects.
Key Words: apoptosis vascular smooth muscle cells E2F1 tumor necrosis factor-
nuclear factor-
B
This article has been cited by other articles:
![]() |
D. A. Goukassian, G. Qin, C. Dolan, T. Murayama, M. Silver, C. Curry, E. Eaton, C. Luedemann, H. Ma, T. Asahara, et al. Tumor Necrosis Factor-{alpha} Receptor p75 Is Required in Ischemia-Induced Neovascularization Circulation, February 13, 2007; 115(6): 752 - 762. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Qin, R. Kishore, C. M. Dolan, M. Silver, A. Wecker, C. N. Luedemann, T. Thorne, A. Hanley, C. Curry, L. Heyd, et al. Cell cycle regulator E2F1 modulates angiogenesis via p53-dependent transcriptional control of VEGF PNAS, July 18, 2006; 103(29): 11015 - 11020. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Qin, M. Ii, M. Silver, A. Wecker, E. Bord, H. Ma, M. Gavin, D. A. Goukassian, Y.-s. Yoon, T. Papayannopoulou, et al. Functional disruption of {alpha}4 integrin mobilizes bone marrow-derived endothelial progenitors and augments ischemic neovascularization J. Exp. Med., January 23, 2006; 203(1): 153 - 163. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Iwakura, C. Luedemann, S. Shastry, A. Hanley, M. Kearney, R. Aikawa, J. M. Isner, T. Asahara, and D. W. Losordo Estrogen-Mediated, Endothelial Nitric Oxide Synthase-Dependent Mobilization of Bone Marrow-Derived Endothelial Progenitor Cells Contributes to Reendothelialization After Arterial Injury Circulation, December 23, 2003; 108(25): 3115 - 3121. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Kishore, C. Luedemann, E. Bord, D. Goukassian, and D. W. Losordo Tumor Necrosis Factor-Mediated E2F1 Suppression in Endothelial Cells: Differential Requirement of c-Jun N-Terminal Kinase and p38 Mitogen-Activated Protein Kinase Signal Transduction Pathways Circ. Res., November 14, 2003; 93(10): 932 - 940. [Abstract] [Full Text] [PDF] |
||||
|
Circulation Research Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2003 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |