Figure 2. Downregulation of Idh2 in senescent mouse embryonic fibroblasts (MEFs) accelerates the senescence phenotype. (A) SA-β-gal staining of control and Idh2-silenced MEFs. Passage 8 (P8) MEFs were used. Scale bar, 200 μm. (B) Statistical analysis of SA-β-gal-stained positive cells between control and Idh2-knockdown MEFs. (C) BrdU levels between control and Idh2-knockdown MEFs as determined by immunocytochemistry. Nuclei were stained with DAPI, and the merged images show BrdU and DAPI signals. Scale bar, 10 μm. (D) Statistical analysis of BrdU-positive cells between control and Idh2-knockdown MEFs. (E) Western blot analysis between control and Idh2-knockdown MEFs. The following antibodies were used for detection: anti-Idh2, anti-p16, anti-p21, anti-p53, and anti- β-actin. Data are expressed as means ± SD (n = 3). *p < 0.05, **p < 0.01, and ***p < 0.001.