Figure 3. Hippo activation promotes cell death in response to oxidative stress.

a, ChIP analysis of in vivo YAP binding to the catalase and MnSOD promoters. H9C2 myoblasts were transduced with the indicated adenovirus for 48 hours. Protein-bound chromatin was prepared and immunoprecipitated with IgG and YAP antibodies. The relative occupancy on the promoters was compared with the input signal (*p<0.05 vs. LacZ, n=3). b–c, Overexpression of Lats2 reduced, whereas knockdown of Lats2 enhanced, catalase and MnSOD protein and mRNA levels. Cardiomyocytes were transduced with the indicated adenovirus. b, The mRNA levels of catalase and MnSOD were examined by quantitative RT-PCR. The relative copy number was normalized with β-actin (*p<0.05 vs. LacZ or sh-con, #p<0.01 vs. LacZ, n=4). c, Lysates were used for immunoblot analysis of catalase, MnSOD and α-tubulin. Results are representative of three individual experiments. d, Cardiomyocytes were transfected with the catalase-luc vector. After 6 hours, myocytes were transduced with the indicated virus and, after 72 hours, luciferase activity was measured (*p<0.05 vs. sh-con/sh-Lats2(−), #p<0.05 vs. sh-con/sh-Lats2(+), n=3). e, Downregulation of Lats2 prevented H₂O₂-induced cell death. Cardiomyocytes transduced with the indicated adenovirus were treated with 100 μM H₂O₂, and TUNEL-positive cells were examined (*p<0.05 vs. sh-con/sh-Lats2(−), #p<0.05 vs. sh-con/sh-Lats2(+), n=4). Data shown as mean±s.e.m.. P values were determined using unpaired Student’s t-test or one-way ANOVA followed by a Newman-Keuls comparison test.