Figure 3: Itgb1 knockdown regulates hepatocytes adhesion and morphology in vivo and ex vivo.

(a) Downregulation of Itgb1 decreases adhesion of isolated hepatocytes to extracellular matrix proteins ex vivo (n=3). (b) Downregulation of Itgb1 in hepatocytes affects ability of hepatocytes to restore their polarity ex vivo. Arrows indicate intercellular space (apical domains) reformed in hepatocytes when cultured in a collagen sandwich. Three independent fields are presented for each treatment. Scale bar, 20 μm. (a,b) Hepatocytes were isolated from mice treated with si-Itgb1 for 10 days (two injections). (c) Long-term silencing of Itgb1 leads to distortion of hepatocyte apical domains (bile canaliculi) in vivo, visualized by Cd13 localization (arrowheads). Subpopulation of enlarged hepatocytes (asterisks) is significantly expanded. Scale bar, 50 μm. (d) Distribution of hepatocyte cell surface in animals treated with si-Itgb1 for 10 weeks. Cell surface was assessed on phalloidin-stained liver sections (~100 cells per animal) using ImageJ software (n=4 per group). (e) Effect of long-term (10 weeks) knockdown of Itgb1 on hepatocyte apical domains (canaliculi) in adult mice treated with si-Itgb1 for 10 weeks. Arrows indicate distorted canaliculi. Scale bar, 50 μm. (f) Increased abundance of activated stellate cells evidenced by immunofluorescent staining for α-smooth muscle actin (α-Sma). Scale bar, 100 μm.