Copper Metabolism of Newborns Is Adapted to Milk Ceruloplasmin As a Nutritive Source of Copper

Abstract

Copper, which can potentially be a highly toxic agent, is an essential nutrient due to its role as a co-factor for cuproenzymes and participation in signaling pathways. In mammals, the liver is a central organ that controls copper turnover throughout the body: copper absorption, distribution, and excretion. In ontogenesis, there are two types of copper metabolism: embryonic and adult, which maintain the balance of copper in each of these periods, respectively. In the liver cells, these types are characterized by specific expression patterns and activity levels of the genes encoding ceruloplasmin, which is the main extracellular ferroxidase and copper transporter and proteins mediating ceruloplasmin metalation. In newborns, the molecular-genetic mechanisms responsible for copper homeostasis and the ontogenetic switch from embryonic to adult copper metabolism are highly adapted to milk ceruloplasmin as a dietary source of copper. In the mammary gland cells, the level of ceruloplasmin gene expression and the alternative splicing of its pre-mRNA govern the amount of ceruloplasmin in milk, and thus, the amount of copper absorbed by the newborn is controlled. In the newborns, absorption, distribution, and accumulation copper are adapted to milk ceruloplasmin. In the newborns, which are not breast-fed at the early stages of postnatal development, the control for alimentary copper balance is absent. We tried to focus on the neonatal consequences of a violation of the balance of copper in the mother / newborn system. Although there is still much to be learned, the time to pay attention to this problem came because the neonatal misbalance of copper may provoke the development of copper related disorders for future life.