Fig 5. Antiapoptotic effect of glucose regulated protein 78 (GRP78) overexpression after Doxorubicin (Dox) treatment.
Neonatal rat cardiomyocytes were transfected with adeno-associated virus 6 expressing GRP78 (AAV-GRP78) or Luciferase (AAV-Luc) two days before treatment with 1μM Dox. (A) Protective window of GRP78 overexpression. The ratio of cleaved caspase3 with Luc treatment (CaspLuc) and cleaved caspase3 with GRP78 treatment (CaspGRP78) was built. Experiments were clustered by GRP78 overexpression and the ratio CaspLuc /CaspGRP78 plotted against GRP78 expression clusters (n = 1–12). (B) GRP78 protein levels (n = 4) and cleaved caspase3 levels (n = 4) after 0h, 24h, 36h and 48h Dox treatment. (C) Dox induced caspase3 cleavage and p53 accumulation with GRP78 overexpression (n = 4). (D) Evaluation of apoptosis by the TUNEL Assay. The ratio of DAPI positive and TUNEL positive nuclei was built (n = 3–5). *p < 0.05 for 2-way ANOVA with Bonferroni post hoc testing.