Scavenger receptor class A member 1 (MSR1)

Scavenger receptor class A member 1 (MSR1), also known as CD204, is a trimeric type II transmembrane glycoprotein primarily expressed on the surface of macrophages and other phagocytic cells (UniProt P21757; NCBI Gene 4481). It belongs to the class A scavenger receptor family and plays a critical role in the innate immune system by acting as a pattern recognition receptor that binds a wide array of ligands, including modified low-density lipoproteins (LDL), bacterial surface components, and apoptotic cells (Nature Reviews Immunology, 2013, PMID: 23928571). In the context of cardiovascular disease, MSR1 is heavily involved in the formation of foam cells during atherosclerosis by mediating the unregulated uptake of oxidized LDL (Journal of Biological Chemistry, 2002, PMID: 12356756). Beyond lipid metabolism, it contributes to host defense against pathogens and the clearance of amyloid-beta in neurodegenerative conditions like Alzheimer's disease (Journal of Alzheimer's Disease, 2005, PMID: 15958731). Therapeutic strategies targeting MSR1 aim to modulate its activity to treat chronic inflammatory diseases, metabolic disorders, and cancer, where it is often expressed on tumor-associated macrophages (Royal Society Open Biology, 2014, PMID: 24714061). While no highly specific small-molecule drugs are currently in widespread clinical use, various polyanionic compounds like fucoidan and monoclonal antibodies are being explored for their potential to inhibit its pro-atherogenic and pro-inflammatory functions (Journal of Immunology, 2017, PMID: 28416601).

Other names

Macrophage scavenger receptor 1CD204SR-ASCARA1Scavenger receptor class A, member 1SR-AISR-AIISR-AIII

Ligand binding followed by receptor-mediated endocytosis or phagocytosis; modulation of toll-like receptor (TLR) signaling and inflammatory cytokine production.