3-nitrotyrosine and Premature-Birth

Oxidative stress and micronutrient deficiencies have been related to lower birth weight (BW), small for gestational age (SGA) offspring and preterm delivery.. The relation between neonatal outcome (BW, head circumference, SGA, preterm delivery) with markers of oxidative stress and micronutrients in maternal and cord blood was to be examined. Oxidative stress markers (protein carbonyls (PrCarb), 3-nitrotyrosine (3NT), malondialdehyde (MDA)), total protein concentration and lipid-soluble micronutrients (carotenoids, retinol, tocopherols) were measured in 200 newborns (11% preterms, 13% SGA) and 151 mothers. Associations between target parameters in cord plasma and maternal serum with BW, head circumference and risk of being SGA or preterm were explored.. Maternal protein concentration, PrCarb, MDA and all lipid-soluble micronutrients were significantly higher compared with newborns, except for 3NT, which was significantly elevated in newborns. Newborn parameters correlated positively with those of mothers. Preterms had lower proteins and retinol but higher PrCarb than terms. Maternal PrCarb and retinol were inversely associated with BW and head circumference. Mothers with PrCarb, MDA and retinol in the highest quintile had a 3.3-fold (0.9; 12.1), 2.1-fold (0.7; 6.4) and 3.3-fold (1.2; 9.4) risk, respectively, for delivering an SGA newborn, whereas the lowest quintile of retinol in cord blood was associated with an increased risk for preterm delivery.. Oxidative stress (elevated PrCarb) was associated with lower BW/head circumference and SGA. Inadequate hemodilution may explain the inverse relation of maternal retinol with BW and head circumference, and the association between highest maternal retinol and risk for SGA.

Topics: Adult; Biomarkers; Birth Weight; Blood Proteins; Female; Fetal Blood; Humans; Infant, Low Birth Weight; Infant, Newborn; Infant, Small for Gestational Age; Male; Malondialdehyde; Micronutrients; Oxidative Stress; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Premature Birth; Protein Carbonylation; Tyrosine; Vitamin A; Vitamin A Deficiency

Infection is known to impair the growth of developing lungs. It is known that plasma free nitrotyrosine (NT) levels can reach 150 μM during sepsis. Free NT incorporates into microtubules and impairs cell function. We hypothesize that free NT perturbs the angiogenic activity of pulmonary artery endothelial cells (PAEC) in developing lungs. PAEC from fetal lamb lungs were incubated with NT (1-100 μM). We examined the effects of NT on tube formation, cell proliferation, apoptosis, and α-tubulin assembly in PAEC. We assessed superoxide anion (O2) and NO levels in PAEC during NT exposure. Effects of NT on endothelial NO synthase (eNOS) were examined with respect to eNOS-dimer formation and the association of eNOS chaperone, heat-shock-protein-90 (hsp90). NT decreased tube formation and increased apoptosis in PAEC. NT also decreased NO levels, increased NOS-dependent O2 generation, and promoted α-tubulin depolymerization. Although NT increased eNOS homodimer formation, it decreased the hsp90 association with eNOS. Our data suggest that increased NT formation during sepsis may uncouple eNOS activity and increase oxidative stress. Because NO plays an important role in angiogenesis and vasodilation, these observations suggest a mechanism for the impaired vasodilation and angiogenesis during sepsis in the developing lung.

Topics: Animals; Apoptosis; Cell Proliferation; Cells, Cultured; Cesarean Section; Endothelial Cells; Gestational Age; HSP90 Heat-Shock Proteins; Lung; Microtubules; Neovascularization, Physiologic; Nitric Oxide; Nitric Oxide Synthase Type III; Premature Birth; Protein Multimerization; Pulmonary Artery; Sepsis; Sheep; Superoxide Dismutase; Superoxides; Tubulin; Tyrosine