A mouse model of humanized liver shows a human-like lipid profile, but does not form atherosclerotic plaque after western type diet

Mouse models are a crucial and often used tool to provide insight into the underlying mechanisms of human atherosclerosis. However, mice profoundly differ from humans in lipoprotein synthesis and metabolism, key factors in atherosclerotic plaque formation. Mouse models often require genetic and dietary modifications to mimic human pathophysiology, shifting from a high-density lipoprotein to an low-density lipoprotein dominant lipoprotein profile. We examined the suitability of mice with a humanized liver as a model for lipoprotein studies and studies on plaque formation, given the central role of hepatocytes in lipoprotein synthesis and metabolism. Our results show a progressive humanization of the mouse liver and a humanized lipoprotein profile. However, no atherosclerotic plaque formation was observed in the studied time frame, despite presence of functional macrophages and application of a high cholesterol western-type diet. The humanized-liver mouse model therefore might require further modifications to induce atherosclerosis, yet seems a valuable model for in vivo studies on lipoprotein metabolism.