Protein Phosphatase 4 Promotes Hepatocyte Lipoapoptosis by Regulating RAC1/MLK3/JNK Pathway

Figure 2

PP4 regulated palmitate-induced lipoapoptosis in hepatocytes. Primary hepatocytes were pretreated with control AD, AD-PP4shRNA, and AD-PP4 for 24 h followed by palmitate treatment. HepG2 was transfected with control siRNA and 2 pairs of PP4 siRNAs for 24 h followed by palmitate treatment. Protein expressions of PP4, PUMA, Bim, c-caspases, and phosphorylation levels of JNK were measured by western blot analysis in murine primary hepatocytes (a) and HepG2 cells (f). Relative protein levels were quantified by densitometry and normalized by GAPDH (b, g). Apoptotic cells were detected by DNA laddering in murine primary hepatocytes (c). TUNEL staining showed apoptotic cells in murine primary hepatocytes (d) and HepG2 cells (h). TUNEL-positive dots were analyzed by the ImageJ software (e, i).