Osteopontin (OPN) is a multifunctional protein found in high concentrations in human milk but only in trace amounts in bovine milk and baby formula. Because bovine milk OPN (bmOPN) is commercially accessible, it may be added to infant formula. OPN performs its many activities by binding to receptors and activating cell signalling pathways. Since the OPN receptor (integrin)-binding site is conserved across species, bmOPN may have bioactive properties in humans and mice. The goal of this work was to look at the bioactivities of bmOPN in a mouse model that already has an OPN knock-out (KO). Researchers examined bmOPN’s bioactivities, such as how it affects intestine growth, immunological response, and brain development. From postnatal day 1 to postnatal day 21, wild-type (WT) pups were breastfed by WT dams, KO dams, or KO dams with bmOPN supplementation. The findings show that orally ingested bmOPN is partially resistant to in vivo gastrointestinal digestion, and supplemental bmOPN exhibited similar effects as mouse milk OPN (mmOPN) on promoting small intestine growth revealed by histological analysis of duodenum villus height and crypt depth at P10, modifying TNF- response to an LPS challenge at P30, and promoting brain myelinating.
The discovery that bmOPN, which has a different amino acid sequence than mmOPN but a conserved integrin binding site, has bioactivities similar to mmOPN implies that bmOPN may offer bioactivities to human newborns when added to formula.