Figure 2. Hypoxia-induced NHE-1 activity occurs in a HIF-1-independent manner.

HT-1080 cells were exposed to normoxic or hypoxic conditions for the indicated times. (A) NHE-1 mRNA expression measured by RT-PCR (n = 3). (B) Representative immunoblot showing NHE-1 expression in cell lysates (n = 3). Actin was used as a loading control. (C) Na⁺/H⁺ exchange rate in HT-1080 cells transfected with HIF-1α shRNA or control (scrambled) shRNA and exposed to 21% O₂ or 1% O₂ for 4 h. Immunoblot showing HIF-1α knock down in cell lysates. Nup62 was used as a loading control. NS: not significant. Columns represent the mean ± SEM indicated by the horizontal bars. The asterisks correspond to, *** p<0.0001.