Neonatal Selenoenzyme Expression Is Variably Susceptible to Duration of Maternal Selenium Deficiency

Maternal selenium (Se) deficiency is associated with decreased neonatal Se levels, which increases the risk for neonatal morbidities. There is a hierarchy to selenoprotein expression after Se deficiency in adult rodents, depending on the particular protein and organ evaluated. However, it is unknown how limited Se supply during pregnancy impacts neonatal selenoprotein expression. We used an Se-deficient diet to induce perinatal Se deficiency (SeD), initiated 2-4 weeks before onset of breeding and continuing through gestation. Neonatal plasma, liver, heart, kidney, and lung were collected on the day of birth and assessed for selenoproteins, factors required for Se processing, and non-Se containing antioxidant enzymes (AOE). Maternal SeD reduced neonatal circulating and hepatic glutathione peroxidase (GPx) activity, as well as hepatic expression of Gpx1 and selenophosphate synthetase 2 (Sps2). In contrast, the impact of maternal SeD on hepatic thioredoxin reductase 1, hepatic non-Se containing AOEs, as well as cardiac, renal, and pulmonary GPx activity, varied based on duration of maternal exposure to SeD diet. We conclude that the neonatal liver and circulation demonstrate earlier depletion in selenoenzyme activity after maternal SeD. Our data indicate that prolonged maternal SeD may escalate risk to the neonate by progressively diminishing Se-containing AOE across multiple organs.