Hepatocyte-targeted siTAZ therapy lowers liver fibrosis in NASH diet-fed chimeric mice with hepatocyte-humanized livers

Interplay between YAP/TAZ and metabolic dysfunction-associated steatotic liver disease progression

Metabolic dysfunction-associated steatotic liver disease (MASLD) is becoming an increasingly pressing global health challenge, with increasing mortality rates showing an upward trend. Two million deaths occur annually from cirrhosis and liver cancer together each year. Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), key effectors of the Hippo signaling pathway, critically regulate tissue homeostasis and disease progression in the liver. While initial studies have shown that YAP expression is normally restricted to cholangiocytes in healthy livers, the activation of YAP/TAZ is observed in other hepatic cells during chronic liver disease. The disease-driven dysregulation of YAP/TAZ appears to be a critical element in the MASLD progression, contributing to hepatocyte dysfunction, inflammation, and fibrosis. In this study, we focused on the complex roles of YAP/TAZ in MASLD and explored how the YAP/TAZ dysregulation of YAP/TAZ drives steatosis, inflammation, fibrosis, and cirrhosis. Finally, the cell-type-specific functions of YAP/TAZ in different types of hepatic cells, such as hepatocytes, hepatic stellate cells, hepatic macrophages, and biliary epithelial cells are discussed, highlighting the multifaceted impact of YAP/TAZ on liver physiology and pathology.

NAFLD and NASH: etiology, targets and emerging therapies

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) pose a significant threat to human health and cause a tremendous socioeconomic burden. Currently, the molecular mechanisms of NAFLD and NASH remain incompletely understood, and no effective pharmacotherapies have been approved. In the past five years, significant advances have been achieved in our understanding of the pathomechanisms and potential pharmacotherapies of NAFLD and NASH. Research advances include the investigation of the effects of the fibroblast growth factor 21 (FGF21) analog pegozafermin and the thyroid hormone receptor-β (THRβ) agonist resmetriom on hepatic fat content, NASH resolution and/or fibrosis regression. Future directions of NAFLD and NASH research (including combination therapy, organoids and humanized mouse models) are also discussed in this state-of-the-art review.