Abstract
Apoptosis of vascular smooth muscle cells (SMCs) is controlled by a balance between the effect of growth factors and cytokines, and is involved in plaque instability in advanced atherosclerotic lesions. Recently, we reported high levels of atheroma-associated cytokines, including tumor necrosis factor-α (TNF-α), in carotid plaques of symptomatic patients. These cytokines induce apoptosis of vascular SMCs, and thus could be responsible for plaque rupture, a clinically devastating event. In this study, we examined the effect of TNF-α on the cell cycle inhibitor p27kip and apoptosis of SMCs in human carotid plaques, and the underlying mechanism. Both Forkhead box subclass o1 (FoxO1) and p27kip were more strongly expressed in symptomatic than asymptomatic atherosclerotic plaques. TNF-α significantly induced the expression of FoxO1 in asymptomatic plaque SMCs in a dose- and time-dependent manner via JNK signaling pathway. TNF-α also induced phosphorylation of FoxO1, resulting in its cytoplasmic translocation/nuclear exclusion of transcription factors. The effect of TNF-α was blocked by the PI3K inhibitor, LY294002. Meanwhile, TNF-α not only induced the p27kip expression and cell cycle arrest in the G0-G1 phase, but also enhanced caspase-3 activity and induced apoptosis in SMCs of asymptomatic plaques. However, the potential effect of TNF-α on the cell cycle inhibitor p27kip and apoptosis of SMCs was inhibited by siRNA against FoxO1 in asymptomatic patients. These data suggest the involvement of FoxO1 transcription factor in TNF-α-induced expression of a cell cycle regulatory protein and apoptosis of SMCs, thus regulating the stability of atherosclerotic plaques with carotid stenosis.
| Original language | English |
|---|---|
| Pages (from-to) | 1-8 |
| Number of pages | 8 |
| Journal | Experimental and Molecular Pathology |
| Volume | 90 |
| Issue number | 1 |
| DOIs | |
| State | Published - Feb 2011 |
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All Science Journal Classification (ASJC) codes
- Clinical Biochemistry
- Molecular Biology
- Pathology and Forensic Medicine
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Tumor necrosis factor-α regulates p27kip expression and apoptosis in smooth muscle cells of human carotid plaques via forkhead transcription factor O1. / Jia, Guanghong; Aggarwal, Anshu; Tyndall, Steve H.; Agrawal, Devendra K.
In: Experimental and Molecular Pathology, Vol. 90, No. 1, 02.2011, p. 1-8.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Tumor necrosis factor-α regulates p27kip expression and apoptosis in smooth muscle cells of human carotid plaques via forkhead transcription factor O1
AU - Jia, Guanghong
AU - Aggarwal, Anshu
AU - Tyndall, Steve H.
AU - Agrawal, Devendra K.
PY - 2011/2
Y1 - 2011/2
N2 - Apoptosis of vascular smooth muscle cells (SMCs) is controlled by a balance between the effect of growth factors and cytokines, and is involved in plaque instability in advanced atherosclerotic lesions. Recently, we reported high levels of atheroma-associated cytokines, including tumor necrosis factor-α (TNF-α), in carotid plaques of symptomatic patients. These cytokines induce apoptosis of vascular SMCs, and thus could be responsible for plaque rupture, a clinically devastating event. In this study, we examined the effect of TNF-α on the cell cycle inhibitor p27kip and apoptosis of SMCs in human carotid plaques, and the underlying mechanism. Both Forkhead box subclass o1 (FoxO1) and p27kip were more strongly expressed in symptomatic than asymptomatic atherosclerotic plaques. TNF-α significantly induced the expression of FoxO1 in asymptomatic plaque SMCs in a dose- and time-dependent manner via JNK signaling pathway. TNF-α also induced phosphorylation of FoxO1, resulting in its cytoplasmic translocation/nuclear exclusion of transcription factors. The effect of TNF-α was blocked by the PI3K inhibitor, LY294002. Meanwhile, TNF-α not only induced the p27kip expression and cell cycle arrest in the G0-G1 phase, but also enhanced caspase-3 activity and induced apoptosis in SMCs of asymptomatic plaques. However, the potential effect of TNF-α on the cell cycle inhibitor p27kip and apoptosis of SMCs was inhibited by siRNA against FoxO1 in asymptomatic patients. These data suggest the involvement of FoxO1 transcription factor in TNF-α-induced expression of a cell cycle regulatory protein and apoptosis of SMCs, thus regulating the stability of atherosclerotic plaques with carotid stenosis.
AB - Apoptosis of vascular smooth muscle cells (SMCs) is controlled by a balance between the effect of growth factors and cytokines, and is involved in plaque instability in advanced atherosclerotic lesions. Recently, we reported high levels of atheroma-associated cytokines, including tumor necrosis factor-α (TNF-α), in carotid plaques of symptomatic patients. These cytokines induce apoptosis of vascular SMCs, and thus could be responsible for plaque rupture, a clinically devastating event. In this study, we examined the effect of TNF-α on the cell cycle inhibitor p27kip and apoptosis of SMCs in human carotid plaques, and the underlying mechanism. Both Forkhead box subclass o1 (FoxO1) and p27kip were more strongly expressed in symptomatic than asymptomatic atherosclerotic plaques. TNF-α significantly induced the expression of FoxO1 in asymptomatic plaque SMCs in a dose- and time-dependent manner via JNK signaling pathway. TNF-α also induced phosphorylation of FoxO1, resulting in its cytoplasmic translocation/nuclear exclusion of transcription factors. The effect of TNF-α was blocked by the PI3K inhibitor, LY294002. Meanwhile, TNF-α not only induced the p27kip expression and cell cycle arrest in the G0-G1 phase, but also enhanced caspase-3 activity and induced apoptosis in SMCs of asymptomatic plaques. However, the potential effect of TNF-α on the cell cycle inhibitor p27kip and apoptosis of SMCs was inhibited by siRNA against FoxO1 in asymptomatic patients. These data suggest the involvement of FoxO1 transcription factor in TNF-α-induced expression of a cell cycle regulatory protein and apoptosis of SMCs, thus regulating the stability of atherosclerotic plaques with carotid stenosis.
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UR - http://www.scopus.com/inward/citedby.url?scp=78649783839&partnerID=8YFLogxK
U2 - 10.1016/j.yexmp.2010.11.001
DO - 10.1016/j.yexmp.2010.11.001
M3 - Article
C2 - 21075101
AN - SCOPUS:78649783839
VL - 90
SP - 1
EP - 8
JO - Experimental and Molecular Pathology
JF - Experimental and Molecular Pathology
SN - 0014-4800
IS - 1
ER -