Figure 4. Liver adiposity and fibrosis are reduced in old mice treated with Alk5i+OT. Livers were collected from non-injured mice and at 5 days post cardiotoxin-induced muscle injury, as illustrated in Figure 1C. (A) 10 µm liver sections were immunostained with Albumin+ (green) using Hoechst dye (blue) to label all nuclei, representative image is shown. (B) Albumin-negative fibrotic clusters (commonly found in old, but not young livers) were quantified; the incidence of fibrosis is reduced in the livers of old injured mice that were administered with Alk5i+OT, as compared to HBSS control **p=0.001, N for old control (Oc)=3, N for old+Alk5i+OT (OA5iOT)=3. (C) Isotype-matched IgG signal for albumin immunodetection was minimal. (D) Representative Oil Red O staining of liver sections show an age-specific increase in adiposity and reduction of old liver adiposity by the Alk5i+OT in both injured and uninjured animals. (E) Image J quantification of red pixel density in the Oil Red O assay was performed, as published (Rebo et al, 2016). Alk5i+OT diminished the liver adiposity of the old injured mice. N=6 in each injured cohort, ****p= 0.002 Oc & OA5iOT, N=6 in each uninjured cohort **p<0.001 Oc & OA5iOT. All scale bars=50 µm.