The Role of Stabilin-1 in Lymphocyte Trafficking and Macrophage Scavenging in the Liver Microenvironment

Chronic liver diseases are a major global health burden, and cases of these conditions continue to rise in many countries. A diverse range of insults can lead to chronic liver disease, but they are all characterised by the infiltration and accumulation of immune cells within liver tissue and, if progressive, can lead to tissue fibrosis and cirrhosis. In this review, we focus on the role of stabilin-1 in two key processes that contribute to liver disease, namely, the recruitment of lymphocytes into liver tissue and the response of macrophages to tissue injury. Stabilin-1 is constitutively expressed on the sinusoidal endothelium of the liver and contributes to the homeostatic scavenging function of these cells. Epithelial damage in the context of chronic liver disease leads to the upregulation of stabilin-1 at sites of tissue injury, specifically at sites of immune cell recruitment and on subpopulations of hepatic macrophages. Functionally, stabilin-1 has been shown to mediate transendothelial migration of lymphocyte subsets in the setting of pro-inflammatory-activated human liver endothelium. In experimental models of liver fibrosis, stabilin-1 promotes the uptake of products of chronic oxidative stress by a subset of hepatic macrophages and suppresses their release of pro-inflammatory mediators that regulate tissue remodelling. These studies highlight the active contribution that scavenger receptors such as stabilin-1 can make in regulating chronic inflammation and tissue fibrosis, and their potential as novel therapeutic targets for these conditions.