Effect of caspase 9 related signaling molecules on the apoptosis of human vascular endothelial cell induced by homocysteine.
OBJECTIVE
To understand the role of mitochondria associated signaling pathway in the apoptosis of human vascular endothelial cell induced by homocysteine (Hcy).


METHODS
The mRNA and protein expression levels of the up-stream signaling molecules of caspase 3, Bcl 2, caspase 9, and cytosolic cytochrome-c, were investigated. The in vitro cultured human umbilical vein endothelial cells with homocysteine at different concentrations were incubated for 24 h. The expressions of Bcl 2 and caspase 9 at mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction(RT-PCR) and Western blot. Cytochrome-c in cytoplasm was also detected by Western blot.


RESULTS
The expression levels of three signaling molecules were all down-regulated by homocysteine at both mRNA and protein levels in a dose-dependent manner.


CONCLUSIONS
Homocysteine could affect the formation of apoptosome through repressing the expression of Bcl 2 gene and release of cytochrome-c from mitochondria. Decreasing of apoptosome could disturb the activation of caspase 9. The results also indicate that the mitochondria pathway is not the major signaling pathway involved in Hcy-induced apoptosis.
Zhang
Ji
J
West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041 PR China.
Wang
Yu-fang
YF
Liang
Wei-bo
WB
Lu
Mei-li
ML
Li
Ying-bi
YB
Wu
Jin
J
Hou
Yi-ping
YP
D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005434:Flow Cytometry; D006711:Homocystine / Q000494:pharmacology*; D006801:Humans; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects
D019253:Proto-Oncogene Proteins c-bcl-2; D006711:Homocystine; D045304:Cytochromes c; D053148:Caspase 3; D053453:Caspase 9