Fig. 2.

4-HPAA is sufficient to reverse HFD-induced hepatic steatosis and liver injury. (A) 4-wk-old male C57BL/6 mice were fed a HFD for 12 wk to induce obesity. After the induction of diet-induced obesity, mice were randomly assigned to receive a subcutaneously implanted control scaffold pellet, or a pellet releasing 350 µg 4-HPAA per day for 2 wk. New pellets were implanted every 2 wk for a total of 6 wk. Lean mass (B) and fat mass (C) were measured by Echo MRI, n = 9–10 per group. (D) 4-HPAA accumulates in the liver as measured by LC-MS/MS, n = 9–10 per group. (E–G) After a total of 18 wk of HFD feeding, H&E-stained sections of the liver revealed profound hepatic steatosis in scaffold control mice, while 4-HPAA-treated mice had marked reversal of steatosis and triglyceride deposition, n = 6–10 per group. (H) NAFLD activity score (NAS) incorporating histologic assessments of steatosis, hepatocellular ballooning, and inflammation. (I and J) Quantification of liver injury biomarkers in peripheral plasma, n = 9–10 per group. Statistical analysis was performed using unpaired two-tailed Student’s t test. Individual points represent individual mice, and bars represent group means. (Fig. 2A reprinted with permission, Cleveland Clinic Foundation ©2022. All Rights Reserved.)