Hepatocyte-Specific Knockout of YAP Protects Against Atherosclerosis via Inhibition of ANGPTL3 in Mice

BACKGROUND: Lipid-lowering therapy is a cornerstone in the treatment of atherosclerotic cardiovascular diseases. Although some lipid-lowering drugs have demonstrated positive effects in patients with atherosclerotic cardiovascular diseases, their effects are limited in those with homozygous familial hypercholesterolemia. It is essential to seek new lipid-lowering targets. YAP (Yes-associated protein) may be involved in lipid metabolism in the liver; therefore, we investigated the function of hepatocyte YAP in hyperlipidemia and atherosclerosis. METHODS: Hyperlipidemia models were generated in apoE knockout (apoE −/− ) mice or mice injected with adeno-associated virus 8–D377Y-mPCSK9, which degrades and deletes LDLR (low-density lipoprotein receptor), by being fed a high-cholesterol diet for 12 weeks. We measured the expression level of hepatic YAP in these apoE −/ − mice. Next, we created YAP ΔHep (hepatocyte-specific deletion of Yes-associated protein) apoE −/− mice to further determine the role of YAP in hyperlipidemia and atherosclerosis. AML12 cells and mice injected with adeno-associated virus 8-D377Y-mPCSK9 or YAP ΔHep apoE −/− mice were used to elucidate its mechanism. Finally, apoE −/− or LDLR knockout (LDLR −/− ) mice were used to observe the therapeutic efficacy of adeno-associated virus 8–Alb (albumin)–shYAP for hyperlipidemia and atherosclerosis. RESULTS: High-cholesterol diet–fed apoE −/− mice showed increased levels of YAP in the liver. Further investigation indicated that YAP ΔHep apoE −/− mice exhibited lighter hyperlipidemia and atherosclerosis than YAP flox/flox apoE −/− mice fed with a high-cholesterol diet. Conversely, hepatocyte-specific overexpression of YAP (5S) deteriorated hyperlipidemia and atherosclerosis in high-cholesterol diet–fed apoE −/− mice. Furthermore, the lipid-lowering effect of YAP deficiency in hepatocytes was independent of LDLR. Hepatocyte-specific overexpression of ANGPTL3 (angiopoietin-like 3) aggravated hyperlipidemia and atherosclerosis in YAP ΔHep apoE −/− mice, indicating that ANGPTL3 is responsible for the function of YAP in hyperlipidemia. Mechanistically, YAP upregulated ANGPTL3 via TEAD (TEA domain family member) 4 in hepatocytes independent of LDLR. Notably, adeno-associated virus 8-Alb-shYAP lowered lipid levels in apoE −/− or LDLR −/− mice. CONCLUSIONS: Taken together, our findings revealed a novel role for the YAP-TEAD4-ANGPTL3 axis in lipid metabolism independent of LDLR. Inhibition of hepatocyte YAP may be an effective lipid-lowering strategy for homozygous familial hypercholesterolemia.