Stabilin2

Stabilin-2, encoded by the STAB2 gene in humans, is a type I transmembrane scavenger receptor that belongs to the scavenger receptor class H (SR-H) family. It is predominantly expressed on liver sinusoidal endothelial cells and is also found in other phagocytic endothelium of the spleen, lymph nodes, and bone marrow. The receptor mediates the uptake and clearance of circulating macromolecules from the bloodstream.

Stabilin-2 binds a range of ligands through its extracellular domain, most notably hyaluronan (hyaluronic acid) and acetylated low-density lipoprotein, enabling receptor-mediated endocytosis and degradation in endosomes. As a membrane protein, it contains cytoplasmic signals that direct internalization and trafficking through the endocytic pathway.

Functionally, Stabilin-2 contributes to the homeostasis of circulating extracellular matrix components, clearance of hyaluronic acid fragments, and removal of cellular debris including apoptotic cells in the liver and other tissues. It operates in concert with Stabilin-1 and other scavenger receptors to perform broad scavenging tasks on the vascular endothelium.

In humans, STAB2 expression and Stabilin-2 activity have been studied within liver physiology, vascular biology, and disease contexts such as liver injury, atherosclerosis, and cancer metastasis, where efficient clearance of HA and other ligands can influence disease progression. Ongoing research seeks to clarify ligand specificity, regulatory mechanisms, and potential therapeutic applications related to Stabilin-2.