Inhibition of microvascular endothelial cell apoptosis by angiopoietin-1 and the involvement of cytochrome C / 中华医学杂志(英文版)
Chinese Medical Journal
;
(24): 725-730, 2006.
Article
in English
| WPRIM
| ID: wpr-267056
ABSTRACT
<p><b>BACKGROUND</b>Angiopoietin-1 (Ang-1) is an endothelial-specific growth factor that can promote angiogenesis. Studies demonstrated that Ang-1 can inhibit apoptosis of umbilical endothelial cells, but so far little is known about its effects on apoptosis of microvascular endothelial cells. With the apoptotic model of murine-cerebral-derived microvascular endothelial cells (bEnd.3) induced by serum-free culture, we attempted to clarify the molecular mechanism of bEnd.3 apoptosis, particularly its relation to cytochrome C (Cyt C).</p><p><b>METHODS</b>The cultured microvascular endothelial cell strain, bEnd.3 cell, was employed. An apoptotic model of bEnd.3 was established by serum-free culture. Flow cytometry after Annexin labeling and PI staining were used to assess the apoptotic effects of Ang-1 on bEnd.3, and the expression of Bax/Bcl-2, caspase 8, caspase 3, and Cyt C were detected with Western blotting and ELISA.</p><p><b>RESULTS</b>The apoptotic rate of bEnd.3 cells after stimulation with Ang-1 (100 ng/L) in serum-free medium was significantly higher than that in control group. Ang-1 inhibited early-stage apoptosis more than late-stage apoptosis provided by propidium iodide (PI) and AnnexinV double staining. The inhibition of Ang-1 on bEnd.3 cell apoptosis was strengthened with the increase in concentration (0 - 400 ng/ml). Ang-1 could decrease the expression of Bax, caspase3 and 8, and increase that of Bcl-2. The results of ELISA indicated that Ang-1 significantly decreased CytC content in cytoplasm and increase that in mitochondria.</p><p><b>CONCLUSIONS</b>Ang-1 could inhibit bEnd.3 apoptosis induced by serum-free medium culture. The apoptosis was associated with decreased Bax expression, increased Bcl-2 expression, which result in Cyt C transferring from mitochondria to cytoplasm, and then caspases activation are reduced and cell apoptosis is suppressed.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Pharmacology
/
Physiology
/
Cells, Cultured
/
Apoptosis
/
Annexin A5
/
Caspases
/
Cell Biology
/
Endothelial Cells
/
Cytochromes c
/
Angiopoietin-1
Type of study:
Prognostic study
Limits:
Animals
Language:
English
Journal:
Chinese Medical Journal
Year:
2006
Type:
Article
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