Loss of p62 impairs the formation of DDC-induced MDBs.

<p><b>(A)</b> H&E staining was performed on liver sections of <i>p62</i>^<i>f/f</i>, <i>p62</i>^<i>-/-</i>, <i>p62hep</i>^<i>+/+</i>and <i>p62hep</i>^<i>-/-</i> mice fed a normal diet (panel 1) or DDC-containing diet for 8 weeks (panel 2). Immunohistochemistry (IHC) with antibodies against p62 (panel 3) and K8/K18 (panel 4) was performed on DDC-intoxicated livers of the indicated genotypes. No morphological signs of liver injury and no MDBs were found in livers under normal diet (panel 1). Large and distinct MDBs (arrows) were only visible in DDC-fed <i>p62</i>^<i>f/f</i> and <i>p62hep</i>^<i>+/+</i> mice in H&E stained sections (panel 2). These MDBs were also decorated by p62 (green; panel 3) and K8/K18 antibodies (red; panel 4). In <i>p62</i>-deficient mice, MDBs are small, less distinct and only decorated by K8/K18 antibodies (arrows; panel 4). MDB-containing hepatocytes display diminished or lacking keratin cytoskeleton (empty cells). Brown pigment in the livers indicates protoporphyrin accumulation. (Scale bar = 50 μm). <b>(B)</b> Immunoblotting revealed abundant p62 expression in livers of DDC-fed <i>p62</i>^<i>f/f</i> and <i>p62hep</i>^<i>+/+</i> mice upon DDC-intoxication while no p62 signal was detected in <i>p62</i>^<i>-/-</i> liver. The minimal p62 signal detected in <i>p62hep</i>^<i>-/</i>- livers reflects preserved p62 expression in non-hepatocytic cells. β-actin was used as a loading control.