Osteopontin (OPN) acts as a cytokine and is involved in enhancing the production of interferon-gamma and IL-12 and reducing the production of IL-10. OPN is essential in the pathway that leads to type I immunity. It appears to form an integral part of the mineralized matrix. OPN is synthesized within the kidney and is present in human urine at levels that can effectively inhibit calcium oxalate crystallization. Decreased concentrations of OPN have been documented in the urine from patients with renal stone disease compared with normal individuals.
Swiss-Prot Accession Number: P10451