Heat Stress Induces Apoptosis through a Ca2+-Mediated Mitochondrial Apoptotic Pathway in Human Umbilical Vein Endothelial Cells
Figure 5
Intense heat stress-induced apoptosis in HUVEC cells over-expressing Bcl-xl.
HUVEC cells stably overexpressing the anti-apoptotic protein Bcl-xl or vector control were cultured at 43°C for 2 h, and further incubated for 6 h. (a) Western blot analysis of bcl-2 protein expression (cropped) in transfected cells. β-actin served as an internal control. (b) and (d) Enzymatic activity of caspase-9, and -3 was measured in cell lysates using the fluorogenic substrates Ac-LEHD-AFC and Ac-DEVD-AMC, respectively, and was expressed relative to the control at 37°C. (c) Expression of Apaf-1 and cleaved PARP were determined by Western blot. (e) Nucleosomal DNA fragmentation was evaluated using DNA electrophoresis and fluorescent staining. Each value is the mean ± SD of at least three separate experiments, *P<0.05, compared with heat stress group (43°C).