CO induces HO-1 expression upon STAT3 phosphorylation.

<p><b>A.</b> and <b>B.</b> EC cultures were incubated with 25 µM TCDC or 5mM MC for the indicated periods. Western blotting analysis was then performed with antibodies against HO-1. <b>C.</b> ECs were transfected with control or HO-1 siRNA vectors for 36 hours and exposed to TCDC or MC for 12 hours. Cell lysates were subjected to western blot analysis with antibodies against pTyr-STAT3 or STAT3. <b>D.</b> ECs were transiently transfected with pcDNA vector or HO-1 plasmid. ECs transfected with pcDNA vector were exposed to IL-6 as a positive control. Cell lysates were subjected to western blot analysis with antibodies against pTyr-STAT3 or STAT3 as indicated. The quantification of the band intensities from three independent experiments was normalized to the control values (if the control was at near background, the background was set to 1). The resulting data are the mean ± SEM. *<i>P</i><0.05 compared with untreated ECs.