Hepatocyte-Specific Yap1 Knockout Maintained the Liver Homeostasis of Lipid Metabolism in Mice

Caige Li,1,2 Yu Xue,1 Yiwei Liu,1 Kangning Zheng,1 Yuting Gao,1,3 Yi Gong,1 Junlan Lu,1 Yuman Zhang,1 Jingmin Ji,1 Zhiqin Zhang,1 Xinli Shi1 1Department of Pathobiology and Immunology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People’s Republic of China; 2Department of Endocrinology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, People’s Republic of China; 3School of Basic Medical Sciences, Shanxi University of Chinese Medicine, Jinzhong, Shanxi, People’s Republic of ChinaCorrespondence: Xinli Shi, Department of Pathobiology and Immunology, Hebei University of Chinese Medicine, 3 Xingyuan Road, Shijiazhuang, Hebei, 050200, People’s Republic of China, Tel +86-0311-89926237, Email sxlsunshine@sina.comIntroduction: Yes-associated protein 1 (YAP1) is a crucial molecule in the Hippo pathway. The impact of hepatocyte-specific Yap1 knockout (Yap1LKO) on hepatic lipid droplets (LD) and pePLIN2 in metabolic fatty liver has not been reported. This study aims to explore whether Yap1LKO could offer a protective effect in a liver injury model.Methods: Three-week-old Yap1LKO and Yap1Flox mice were given aristolochic acid I (AAI) combined carbon tetrachloride (CCL4) establish liver injury model. Eight-week-old Yap1LKO and Yap1Flox mice were fed with a high-fat diet for 18 weeks to establish obesity-related liver injury model. Further biochemical, histomorphological, immunohistochemical, and lipidomic analyses were performed on serum and liver tissues of these mice to elucidate the effects of hepatocyte-specific Yap1 knockout on hepatic lipid metabolism.Results: Yap1LKO reduced triglyceride (TG) content and PLIN2 expression level in the liver during the intervention of AAI combined CCl4. Moreover, Yap1LKO improved lipid metabolism homeostasis in the liver by increasing the beneficial lipid molecules and reducing the harmful lipid molecules through lipidomics. Finally, Yap1LKO reduced TG content in the serum and liver, hepatic vacuolar degeneration, and hepatic PLIN2 expression level in mice fed with a high-fat diet (HFD).Conclusion: Yap1LKO is protective in regulating liver and blood TG when induced with toxic substances AAI combined CCl4 and a high-fat diet.Keywords: yes-associated protein, hepatocyte-specific Yap1 knockout, perilipin-2, lipidomic, triglyceride