Stabilin1

Stabilin-1 is a transmembrane scavenger receptor encoded by the STAB1 gene in humans. It is expressed predominantly on liver sinusoidal endothelial cells and on macrophages in spleen, lymph nodes, and bone marrow, where it participates in the clearance of circulating and tissue-associated ligands.

Functionally, Stabilin-1 acts as a receptor-mediated endocytosis system that binds a broad range of negatively charged, or anionic, ligands and mediates their uptake for lysosomal degradation. This scavenging activity contributes to the maintenance of tissue and plasma homeostasis by removing extracellular matrix components and other macromolecules from circulation and tissues. Stabilin-1 is involved in the clearance of hyaluronic acid and dermatan sulfate, with additional ligands including modified forms of lipoproteins and other glycosaminoglycans described in the literature.

Structurally, Stabilin-1 is a large type I transmembrane glycoprotein featuring extracellular domains that support ligand binding and a cytoplasmic tail containing internalization signals to recruit endocytic machinery.

Physiological significance includes roles in hyaluronan clearance, body fluid homeostasis, and immune surveillance. In concert with Stabilin-2, Stabilin-1 contributes to systemic scavenging and tissue remodeling. Experimental models show that loss or dysfunction of Stabilin-1 can impair clearance of HA and other ligands, with potential downstream effects on inflammation and liver and spleen physiology.

Further study of STAB1 continues to elucidate its involvement in health and disease, including liver pathology and inflammatory conditions, and its potential as a biomarker or therapeutic target in contexts of impaired clearance.