Fig. 7.

Downregulation of mitochondrial DNA-encoded mRNA expression in mito-HIF-1α-transfected cells. Transfected HeLa cells were exposed to hypoxia for 8 h and then analyzed. A. qRT-PCR analysis of the indicated mitochondrial mRNAs. Data were normalized to RPS18. B-G. Immunoblot analysis (B) and corresponding quantification (C–G) of mitochondrial gene encoding proteins in whole cell lysates of transfected cells after 16 h of hypoxia. H. The ratio of mitochondrial DNA to nuclear DNA was determined by quantification of COII and Cyt B by qRT-PCR. Data were normalized to RPS18 and β-globin. I. Citrate synthase activity in whole cell lysates. J, K. Flow cytometry histograms (J) and quantification (K) of MitoTracker Deep Red fluorescence intensity. Data are the means ± SEM (n ≥ 3). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. ns, not significant.