Scavenger receptor cysteine-rich type 1 protein M130

CD163 (scavenger receptor cysteine-rich type 1 protein M130) is a macrophage-expressed receptor that mediates the clearance and endocytosis of hemoglobin/haptoglobin complexes, protecting tissues from hemoglobin-mediated oxidative damage and facilitating iron recycling via heme breakdown (UniProt: Q86VB7). The receptor binds its ligands in a calcium- and pH-dependent manner and triggers intracellular signaling cascades involving tyrosine kinase activation, calcium mobilization, and cytokine secretion. Upon shedding, the soluble form (sCD163) may exert anti-inflammatory effects and serves as a biomarker for macrophage activation in inflammatory conditions.

CD163 is relevant to Alzheimer's Disease pathology. In human post-mortem AD brain tissue compared to age-matched controls, CD163 is significantly upregulated (mean log2 fold-change: 1.00; Chaparral AD proteomics), suggesting increased macrophage involvement or activation in AD-affected brain regions. This elevation may reflect enhanced hemoglobin clearance and iron metabolism dysregulation, or alternatively heightened neuroinflammatory responses characteristic of AD neurodegeneration.