Molecular Characterization and Expression of Lactoferrin Receptor (LfR) in Different Regions of the Brain Responding to Lactoferrin Intervention: a Mechanism for Neurodevelopment and Cognition in Piglets

Abstract Lactoferrin (LF) promotes neurodevelopment and cognition, but whether it acts through the LF receptor (LfR) and its expression profile in the brain remains unknown. We characterized 972 bp of piglet brain LfR cDNA and found LfR mRNA was expressed all brain regions being highest in the frontal lobe, followed by parietal lobe, brainstem, occipital lobe, cingulate gyrus, subventricular zone, olfactory bulb, hippocampus, amygdala, cerebellum and thalamus. LfR mRNA and protein in different regions of the brain responded to low (155) and high (285 mg/kg/day) LF supplementation of piglets from postnatal day 3 to 38. Low LF diet significantly increased LfR protein expression in the occipital lobe compared to controls, but not the high LF diet. LfR protein in the subventricular zone of the high LF group was 42% and 38% higher than that of the low LF group and controls, respectively. There was a trend for a dose-response relationship between LF intervention and LfR protein expression in the prefrontal and parietal lobes. LF supplementation significantly improved piglet working memory for a difficult task, which was correlated with brain LfR protein, but no dose-response. Brain LfR responds to dietary LF supplementation, a mechanism by which LF can promote learning and working memory through its receptor. LfR is expressed in the whole brain, and its expression level is anatomic region specific.