Apoptotic Response through a High Mobility Box 1 Protein-Dependent Mechanism in LPS/GalN-Induced Mouse Liver Failure and Glycyrrhizin-Mediated Inhibition
Figure 3
Acetylation of HMGB1 and HDAC activity by LPS/GalN-treatment.
Immunohistochemistry with antibodies against acetylated-lysine (A–H) and HDAC activity (I, J). Immunoreactive products are found in the nuclei of only a few hepatocytes in control mice (A, G). The hepatocytes with nuclear immunoreactivity are significantly increased in number 1–6 h after treatment (B, C, G). At 8 h of the concomitant administration of LPS/GalN, the nuclear immunoreactivity for acetylated-lysine is strongly reduced (D, G) and immunolabeled products are exclusively found in the extracelluar milieu of pericentral areas (D). At 10 h a distinct nuclear expression of acetylated-lysine is significantly increased in hepatocytes (E, G). Administration of GL remarkably reduces the immunoreactive, cytoplasmic and extracellular response to acetylated-lysine in the pericentral areas (F) and shows a significant increase in the number of nuclear immunoreactive products for acetylated-lysine (H). Colorimetric assay for histone deacetylase (HDAC) activity shows that the cytoplasmic (I) and nuclear (J) HDAC activity is increased in both liver tissues after LPS/GalN- or GL+LPS/GaIN-treatment compared with baseline animals, but not significant. CV: central vein; Bars = 200 μm for A–F. #Significant difference from values of 3 h after LPS/GalN treatment (P<0.05; G), §significant difference from values of 6 or 10 h after treatment (P<0.05; G), and *significant difference between groups treated with LPS/GalN alone and GL plus LPS/GalN (P<0.05; H).