Figure 2. Hypoxia-Induced Mitochondrial Fission Is Impaired in the Absence of Siah Expression.

(A) Siah1a/2^WT and Siah1a/2^DKO MEFs expressing mito-RFP were incubated for 24 hr under indicated oxygen concentrations. Mitochondria morphology was quantified from 300–600 cells from three different experiments.

(B) NIH 3T3 cells expressing mito-RFP were transfected with GFP, GFP-Siah2^WT, or GFP-Siah2^RM. Mitochondria morphology from 200 cells with positive GFP was quantified.

(C) Siah1a/2^WT MEFs stably transduced with shSiah2 lentivirus were incubated under indicated oxygen conditions. Mitochondria were visualized with anti-Tom20 antibody and quantified. For (A)–(C), data are presented as mean ± SD. Scale bars indicate 10 µm.

(D) The efficiency of Siah2 shRNA is shown through corresponding RT-PCR bands. The ratio of band intensity was quantified using NIH Image J software and normalized with corresponding β-actin bands.