Terf2ip deficiency accelerate non-alcoholic steatohepatitis through regulating lipophagy and fatty acid oxidation via Sirt1/ AMPK pathway.

BACKGROUND & AIMS: Our previous study has demonstrated that Telomeric repeat-binding factor 2-interacting protein 1(Terf2ip), played an important role in hepatic ischemia reperfusion injury. This study is aimed to explore the function and mechanism of Terf2ip in non-alcoholic steatohepatitis (NASH).

METHODS: The expression of Terf2ip was detected in liver tissue samples obtained from patients diagnosed with NASH. Mice NASH models were constructed by fed with high-fat diet (HFD) or methionine/choline deficient diet (MCD) in Terf2ip knockout and wild type (WT) mice. To further investigate the role of Terf2ip in NASH, adeno-associated viruses (AAV)-Terf2ip was administrated to mice.

RESULTS: We observed a significant down-regulation of Terf2ip levels in the livers of NASH patients and mice NASH models. Terf2ip deficiency was associated with an exacerbation of hepatic steatosis in mice under HFD or MCD. Additionally, Terf2ip deficiency impaired lipophagy and fatty acid oxidation (FAO) in NASH models. Mechanically, we discovered that Terf2ip bound to the promoter region of Sirt1 to regulate Sirt1/AMPK pathway activation. As a result, Terf2ip deficiency was shown to inhibit lipophagy through the AMPK pathway, while the activation of Sirt1 alleviated steatohepatitis in the livers of mice. Finally, re-expression of Terf2ip in hepatocyes alleviated liver steatosis, inflammation, and restored lipophagy.

CONCLUSIONS: These results revealed that Terf2ip played a protective role in the progression of NASH through regulating lipophagy and FAO by binding to Sirt1 promoter. Our findings provided a potential therapeutic target for the treatment of NASH.