FIGURE 3.

HIF-1α silencing abrogates hypoxia-induced FBLN5 up-regulation. A, HUVEC were transfected with a HIF-1α specific siRNA (siHIF-1α) or a control siRNA (siRAND), and HIF-1α and HIF-2α mRNA levels were determined by real-time PCR. Data are expressed as mean ± S.E. (n = 6; *, p < 0.05 versus siRAND cells). B, Western blot analysis confirms the blockade of HIF-1α protein levels by siHIF-1α under hypoxic conditions, whereas HIF-2α expression remained unchanged (Norm, normoxia; Hyp, hypoxia). C, HIF-1α silencing prevents the hypoxia-mediated up-regulation of FBLN5 and VEGF mRNA levels evaluated by real-time PCR. Results are expressed as mean ± S.E. (n = 9; * and †, p < 0.05 versus normoxic cells transfected with a siRAND and versus hypoxic cells transfected with a siRAND, respectively). D, FBLN5 protein levels were analyzed by Western blot in HUVEC transfected with a siHIF-1α or a control siRNA (siRAND) under normoxic or hypoxic conditions. A representative autoradiogram of two independent experiments is shown.