OSCAR (gene)

OSCAR is a gene in humans and other mammals that encodes a protein belonging to the leukocyte receptor complex (LRC) family, which are a diverse set of cell surface receptors primarily expressed on immune cells. OSCAR stands for Osteoclast Associated, Immunoglobulin-like Receptor.

The OSCAR protein is an immunoreceptor expressed on osteoclasts and neutrophils. It is a type I transmembrane glycoprotein containing two extracellular Ig-like domains. Its extracellular domain binds to collagen, suggesting a role in collagen-mediated signaling.

Specifically, OSCAR functions as a collagen receptor that stimulates osteoclastogenesis, the process of forming osteoclasts which are cells responsible for bone resorption. Through its interaction with collagen, OSCAR activates intracellular signaling pathways that promote the differentiation and activity of osteoclasts. This activity contributes to bone remodeling and repair, and is implicated in bone-related diseases like osteoporosis and rheumatoid arthritis.

Genetic variation in the OSCAR gene has been associated with differences in bone mineral density and susceptibility to fractures. Research suggests that OSCAR polymorphisms may influence the degree of OSCAR-mediated osteoclast activation, thereby impacting bone mass and strength.

Further research is ongoing to fully elucidate the precise mechanisms of OSCAR signaling and its role in various physiological and pathological processes. The potential of targeting the OSCAR pathway for therapeutic intervention in bone diseases is also under investigation.