Inhibitor of DNA Binding 1 Is Induced during Kidney Ischemia-Reperfusion and Is Critical for the Induction of Hypoxia-Inducible Factor-1α

Figure 6

ID1 is required for HIF-1α induction in the H/R model. HK-2 cells were transiently transfected with specific siRNA for ID1 or siRNA for negative control and then subjected to H/R. (a) In cells transfected with ID1 siRNA, the expression of ID1 was markedly inhibited. HIF-1α protein expression was remarkably suppressed after exposure to hypoxia for 24 hours or to reoxygenation for 12 or 24 hours. β-actin expression was examined as the loading control. A representative blot from 3 independent experiments is shown. (b, c) In cells transfected with ID1 siRNA, relative mRNA levels of ID1 were efficiently reduced. Relative mRNA levels of HIF-1α were decreased significantly after 24 hours of hypoxia and 12 hours of reoxygenation. β-actin mRNA served as an internal control (). compared with the negative control (scramble). compared with the prehypoxia controls. ID1, inhibitor of DNA binding 1; HIF-1α, hypoxia-inducible factor-1 alpha; H/R, hypoxia-reoxygenation.

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