@article{APS4877,
author = {Jie Yin and Ya-juan Wan and Shi-yang Li and Ming-juan Du and Cui-zhu Zhang and Xing-long Zhou and You-jia Cao},
title = {The distinct role of guanine nucleotide exchange factor Vav1 in Bcl-2 transcription and apoptosis inhibition in Jurkat leukemia T cells},
journal = {Acta Pharmacologica Sinica},
volume = {32},
number = {1},
year = {2016},
keywords = {},
abstract = {Aim: To investigate a novel function of proto-oncogene Vav1 in the apoptosis of human leukemia Jurkat cells.
Methods: Jurkat cells, Jurkat-derived vav1-null cells (J.Vav1) and Vav1-reconstituted J.WT cells were treated with a Fas agonist antibody, IgM clone CH11. Apoptosis was determined using propidium iodide (PI) staining, Annexin-V staining, DNA fragmentation, cleavage of caspase 3/caspase 8, and poly (ADP-ribose) polymerase (PARP). Mitochondria transmembrane potential (ΔΨm) was measured
using DiOC6(3) staining. Transcription and expression of the Bcl-2 family of proteins were evaluated using semi-quantitative RT-PCR and western blot, respectively. Bcl-2 promoter activity was analyzed using luciferase reporter assays.
Results: Cells lacking Vav1 were more sensitive to Fas-mediated apoptosis than Jurkat and J.WT cells. J.Vav1 cells lost mitochondria transmembrane potential (ΔΨm) more rapidly upon Fas induction. These phenotypes could be rescued by re-expression of Vav1 in J.Vav1 cells. The expression of Vav1 increased the transcription of pro-survival Bcl-2. The guanine nucleotide exchange activity of Vav1
was required for enhancing Bcl-2 promoter activity, and the Vav1 downstream substrate, small GTPase Rac2, was likely involved in the control of Bcl-2 expression.
Conclusion: Vav1 protects Jurkat cells from Fas-mediated apoptosis by promoting Bcl-2 transcription through its GEF activity.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/4877}
}