SDHa silencing increases HIF-1 target gene expression in H9c2 cells.
A, Western blot analysis of glucose transporter proteins Glut1,
Glut2, and Glut4 in control lysate (lanes 1 and 2) or lysate
from cells transfected with siRNA to SDHa. Lanes 3,
4, lanes 5, 6, and lanes 7, 8 show timed
effects of SDHa siRNA on transporter levels. Tubulin is the loading
control. The histogram shows Glut 1, 2, and 4 protein levels by densitometry
(*, p < 0.05 compared with control; † indicates
p < 0.05 compared with control and Glut1). B, Western
blot analysis for HO-1 in H9c2 cell lysates described in A shows
protein induction after SDHa silencing. (Tubulin is for comparison.) The
histogram shows relative HO-1 induction by densitometry (n = 3;
*, p < 0.05 compared with control). C, siNRF-1
causes the expected increases in Glut4 and HO-1 protein by Western blot
analysis by 24 h. In duplicate experiments, densitometry indicated that both
proteins increased after siNRF-1 by an amount comparable to siSDHa
(∼2-fold and 3-fold respectively; p < 0.05 for both).