Mal is essential for the expression of HO-1 induced by MALP-2.

<p><b>A.</b> Cells were transiently transfected with a dominant negative plasmid encoding Mal (DN-Mal) or empty vector (pDeNy, lane 2). Cell lysates were prepared, and samples were immunoblotted with an anti-HO-1 antibody. <b>B.</b> Cells were transfected with Mal siNRA or control siRNA, and then treated with MALP-2 (5 ng/ml) for 16 h. Expression of Mal and HO-1 were analyzed by Western blot. <b>C.</b> Cells were cotransfected with a DN-MyD88 or DN-Mal and HO-1-luc reporter gene, and then treated with MALP-2 for 8 h. The luciferase activity derived from HO-1 activation was normalized to the transfection efficiency with β-gal, and pDeNy was used as a control vector. All values are expressed as means ± SEM obtained from three independent experiments. *, P<0.05 and **, P<0.01 for significant difference between compared groups.</p>