Abstract
Background - Endothelial progenitor cells (EPCs) contribute to vascular regeneration/repair and thus may protect against scleroderma vasculopathy. We aimed to determine whether circulating EPCs were reduced in scleroderma, whether scleroderma sera could induce EPC apoptosis, and, if so, what the underlying apoptotic signaling pathway was. Methods and Results - Circulating EPC levels were quantified in 54 patients with scleroderma and 18 healthy control subjects by colony-forming unit assay and flow cytometry, which revealed markedly decreased EPC levels in scleroderma patients relative to healthy subjects. Substantial apoptosis was detected in EPCs after culturing in the presence of scleroderma sera compared with normal sera. Intriguingly, depletion of the IgG fraction from scleroderma sera completely abolished the apoptotic effects. Furthermore, scleroderma sera inhibited the activation/phosphorylation of Akt, which in turn suppressed the phosphorylation and degradation of forkhead transcription factor FKHRL1 (FOXO3a), resulting in the upregulation of apoptotic protein Bim. siRNA-mediated FOXO3a and Bim knockdown substantially reduced scleroderma serum-induced EPC apoptosis. Importantly, Bim expression and baseline apoptosis were increased in EPCs freshly isolated from scleroderma patients relative to that obtained from healthy subjects. Conclusion - Scleroderma serum-induced EPC apoptosis is mediated chiefly by the Akt-FOXO3a-Bim pathway, which may account, at least in part, for the decreased circulating EPC levels in scleroderma patients.
| Original language | English |
|---|---|
| Pages (from-to) | 2156-2165 |
| Number of pages | 10 |
| Journal | Circulation |
| Volume | 118 |
| Issue number | 21 |
| DOIs | |
| State | Published - Nov 18 2008 |
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Keywords
- Angiogenesis
- Antibodies
- Apoptosis
- Endothelial progenitor cells
- Scleroderma
ASJC Scopus subject areas
- Physiology (medical)
- Cardiology and Cardiovascular Medicine
Cite this
Transcriptional regulation of Bim by FOXO3a and Akt mediates scleroderma serum-induced apoptosis in endothelial progenitor cells. / Zhu, Shoukang; Evans, Sarah; Yan, Bin; Povsic, Thomas J.; Tapson, Victor; Goldschmidt-Clermont, Pascal; Dong, Chunming.
In: Circulation, Vol. 118, No. 21, 18.11.2008, p. 2156-2165.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Transcriptional regulation of Bim by FOXO3a and Akt mediates scleroderma serum-induced apoptosis in endothelial progenitor cells
AU - Zhu, Shoukang
AU - Evans, Sarah
AU - Yan, Bin
AU - Povsic, Thomas J.
AU - Tapson, Victor
AU - Goldschmidt-Clermont, Pascal
AU - Dong, Chunming
PY - 2008/11/18
Y1 - 2008/11/18
N2 - Background - Endothelial progenitor cells (EPCs) contribute to vascular regeneration/repair and thus may protect against scleroderma vasculopathy. We aimed to determine whether circulating EPCs were reduced in scleroderma, whether scleroderma sera could induce EPC apoptosis, and, if so, what the underlying apoptotic signaling pathway was. Methods and Results - Circulating EPC levels were quantified in 54 patients with scleroderma and 18 healthy control subjects by colony-forming unit assay and flow cytometry, which revealed markedly decreased EPC levels in scleroderma patients relative to healthy subjects. Substantial apoptosis was detected in EPCs after culturing in the presence of scleroderma sera compared with normal sera. Intriguingly, depletion of the IgG fraction from scleroderma sera completely abolished the apoptotic effects. Furthermore, scleroderma sera inhibited the activation/phosphorylation of Akt, which in turn suppressed the phosphorylation and degradation of forkhead transcription factor FKHRL1 (FOXO3a), resulting in the upregulation of apoptotic protein Bim. siRNA-mediated FOXO3a and Bim knockdown substantially reduced scleroderma serum-induced EPC apoptosis. Importantly, Bim expression and baseline apoptosis were increased in EPCs freshly isolated from scleroderma patients relative to that obtained from healthy subjects. Conclusion - Scleroderma serum-induced EPC apoptosis is mediated chiefly by the Akt-FOXO3a-Bim pathway, which may account, at least in part, for the decreased circulating EPC levels in scleroderma patients.
AB - Background - Endothelial progenitor cells (EPCs) contribute to vascular regeneration/repair and thus may protect against scleroderma vasculopathy. We aimed to determine whether circulating EPCs were reduced in scleroderma, whether scleroderma sera could induce EPC apoptosis, and, if so, what the underlying apoptotic signaling pathway was. Methods and Results - Circulating EPC levels were quantified in 54 patients with scleroderma and 18 healthy control subjects by colony-forming unit assay and flow cytometry, which revealed markedly decreased EPC levels in scleroderma patients relative to healthy subjects. Substantial apoptosis was detected in EPCs after culturing in the presence of scleroderma sera compared with normal sera. Intriguingly, depletion of the IgG fraction from scleroderma sera completely abolished the apoptotic effects. Furthermore, scleroderma sera inhibited the activation/phosphorylation of Akt, which in turn suppressed the phosphorylation and degradation of forkhead transcription factor FKHRL1 (FOXO3a), resulting in the upregulation of apoptotic protein Bim. siRNA-mediated FOXO3a and Bim knockdown substantially reduced scleroderma serum-induced EPC apoptosis. Importantly, Bim expression and baseline apoptosis were increased in EPCs freshly isolated from scleroderma patients relative to that obtained from healthy subjects. Conclusion - Scleroderma serum-induced EPC apoptosis is mediated chiefly by the Akt-FOXO3a-Bim pathway, which may account, at least in part, for the decreased circulating EPC levels in scleroderma patients.
KW - Angiogenesis
KW - Antibodies
KW - Apoptosis
KW - Endothelial progenitor cells
KW - Scleroderma
UR - http://www.scopus.com/inward/record.url?scp=57449114150&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=57449114150&partnerID=8YFLogxK
U2 - 10.1161/CIRCULATIONAHA.108.787200
DO - 10.1161/CIRCULATIONAHA.108.787200
M3 - Article
VL - 118
SP - 2156
EP - 2165
JO - Circulation
JF - Circulation
SN - 0009-7322
IS - 21
ER -