Serum selenium levels of the very low birth weight premature newborn infants with bronchopulmonary dysplasia

Selenium Deficiency Exacerbates Hyperoxia-Induced Lung Injury in Newborn C3H/HeN Mice

Extremely preterm infants are often treated with supraphysiological oxygen, which contributes to the development of bronchopulmonary dysplasia (BPD). These same infants exhibit compromised antioxidant capacities due in part to selenium (Se) deficiency. Se is essential for basal and inducible antioxidant responses. The present study utilized a perinatal Se deficiency (SeD) mouse model to identify the combined effects of newborn hyperoxia exposure and SeD on alveolarization and antioxidant responses, including the identification of affected developmental pathways. Se-sufficient (SeS) and SeD C3H/HeN breeding pairs were generated, and pups were exposed to room air or 85% O2 from birth to 14 d. Survival, antioxidant protein expression, and RNA seq analyses were performed. Greater than 40% mortality was observed in hyperoxia-exposed SeD pups. Surviving SeD pups had greater lung growth deficits than hyperoxia-exposed SeS pups. Gpx2 and 4 protein and Gpx activity were significantly decreased in SeD pups. Nrf2-regulated proteins, Nqo1 and Gclc were increased in SeD pups exposed to hyperoxia. RNA seq revealed significant decreases in the Wnt/β-catenin and Notch pathways. Se is a biologically relevant modulator of perinatal lung development and antioxidant responses, especially in the context of hyperoxia exposure. The RNA seq analyses suggest pathways essential for normal lung development are dysregulated by Se deficiency.

Selenium status in term neonates, according to birth weight and gestational age, in relation to maternal hypertensive pathology

Background

Pregnancy represents a state of increased oxidative stress and antioxidants, in which selenium (Se) plays a pivotal role, contribute to maintain the oxidative balance. If antioxidant defenses are depleted, placental function is disrupted, resulting in pregnancy complications, including pregnancy-induced hypertension (PIH). Little is known about fetal selenium status in concomitant relation to maternal PIH, gestational age (GA) and birthweight (BW).

Methods

We examined over a 3-year period the serum (SeS) and urine selenium (SeU) status in term neonates from normotensive (nonPIH) and hypertensive (PIH) mothers as clinical markers of oxidative stress. In this retrospective observational study, 72 neonates with maternal PIH were matched for GA and BW to 72 neonates of normotensive mothers. Four groups were obtained, based on maternal PIH and BW relative to GA (appropriate-for-gestational-age-AGA, small-for-gestational-age-SGA): nonPIH-AGA (control group), nonPIH-SGA, PIH-AGA, and PIH-SGA.

Results

The results showed significant differences (p < 0.001) in selenium levels among the study groups: SeS - 44.85 ± 7.56 μg/L in nonPIH-AGA, 39.62 ± 11.42 μg/L in nonPIH-SGA, 40.01 ± 10.07 μg/L in PIH-AGA, and 25.39 ± 8.99 μg/L in PIH-SGA; SeU - 27.98 ± 7.99 μg/L in nonPIH-AGA, 22.85 ± 9.48 μg/L in nonPIH-SGA, 23.44 ± 6.73 μg/L in PIH-AGA, and 13.05 ± 5.86 μg/L in PIH-SGA. Selenium depletion was more common in neonates born from hypertensive mothers and those born small for gestational age. Though moderate in intensity, selenium levels were positively correlated with BW (0.319 for SeS, 0.397 for SeU) and negatively correlated with maternal systolic blood pressure (-0.313 for SeS, -0.324 for SeU). The main independent effects on SeS and SeU of each maternal blood pressure and birth weight turned out statistically significant. In interaction, a more pronounced effect was reached in PIH-SGA neonates.

Conclusion

Selenium status seemed to reflect the negative impact that PIH exerts in neonates during intrauterine development. Clinical markers of selenium status could thus be of great value for tracking responses of individuals to selenium supplementation as part of health improvement and harm mitigation approaches.

Antioxidants: Role the in prevention and treatment of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is one of the major causes of chronic respiratory diseases among infants. Both pharmacological and nonpharmacological approaches have been proposed for its management. Since oxidative stress is known to play a pivotal role in the pathogenesis of BPD, it is reasonable to consider the potential of antioxidant strategies in the prevention and treatment of this condition. Indeed, antioxidants can prevent or inhibit substrate oxidation. Some studies have evaluated the efficacy of the exogenous administration of vitamins and micronutrients in reducing the propagation of free radicals through their scavenging capacity. Nonetheless, encouraging preclinical results did not translate into effective preventive and/or therapeutic interventions. This narrative review evaluates the current evidence about the antioxidants that are potentially useful for preventing and treating BPD and explores the most relevant issues affecting their implementation in clinical practice, as well as their associated evidence gaps and research limitations.

Selenoproteins in the Human Placenta: How Essential Is Selenium to a Healthy Start to Life?

Selenium is an essential trace element required for human health, and selenium deficiency has been associated with many diseases. The daily recommended intake of selenium is 60 µg/day for adults, which increases to 65 µg/day for women when pregnant. Selenium is incorporated into the 21st amino acid, selenocysteine (sec), a critical component of selenoproteins that plays an important role in a variety of biological responses such as antioxidant defence, reactive oxygen species (ROS) signalling, formation of thyroid hormones, DNA synthesis and the unfolded protein response in the endoplasmic reticulum (ER). Although 25 selenoproteins have been identified, the role of many of these is yet to be fully characterised. This review summarises the current evidence demonstrating that selenium is essential for a healthy pregnancy and that poor selenium status leads to gestational disorders. In particular, we focus on the importance of the placental selenoproteome, and the role these proteins may play in a healthy start to life.

Association between DNA Damage and Serum Levels of Copper, Zinc, and Selenium in Full-Term Neonates with Late-Onset Sepsis

Objective The alteration in certain trace elements is usually associated with impaired immune function and higher oxidative stress. Therefore, these elements are suggested to play an important role in the pathogenesis of neonatal sepsis. We aimed to evaluate copper (Cu), zinc (Zn), and selenium (Se) serum levels in full-term neonates with late-onset sepsis (LOS) and correlate these levels with DNA damage and other risk factors of sepsis.

Methods The study included a group of 100 neonates diagnosed with sepsis serving as the case group and another one of 60 neonates serving as the control group. DNA damage was assessed using the comet assay method and trace elements were measured using inductively coupled plasma mass spectrometry.

Results Compared with controls, the percentage of DNA damage was significantly elevated in patients with sepsis, while serum levels of Cu, Zn, and Se were markedly decreased (p = 0.001). A strong negative correlation was revealed between Se and DNA damage (r = −0.6, p = 0.001). However, no correlations were found between Cu or Zn and DNA damage. Univariate logistic regression analysis revealed that DNA damage as well as Cu, Zn, and Se serum levels can be considered as relevant risk factors for neonatal sepsis (p = 0.008, 0.004, 0.004, and 0.003, respectively). Receiver-operating characteristic curve analysis showed that the strongest indicator for neonatal sepsis was Se (area under the curve [AUC] = 0.94, confidence interval [CI] = 0.9–0.98, p = 0.001), followed by Cu (AUC = 0.9, CI = 0.85–0.96, p = 0.001), and then Zn (AUC = 0.87, CI = 0.8–0.93, p = 0.001).

Conclusion The percentage of DNA damage may help in the assessment of neonatal sepsis severity. Altered levels of Cu, Zn, and Se may play significant role in the pathogenesis of neonatal sepsis. Se serum level is strongly correlated with percentage of DNA damage. Therefore, Se can predict the severity of LOS.

Selenium: implications for outcomes in extremely preterm infants

Extremely preterm infants are at high risk for morbidities including bronchopulmonary dysplasia, intraventricular hemorrhage, and retinopathy of prematurity likely related to their exposure to reactive oxygen and nitrogen species early in life. Selenium is a trace mineral contributes to the proper function of multiple systems including immunity, redox regulation, and inflammation via the "selenoenzymes" glutathione peroxidase, thioredoxin reductase, and selenoprotein P. Given that selenium accretion via the placenta occurs primarily during the third trimester, preterm neonates are born selenium deficient. While the role of selenium in animals and adults is better described, publications are lacking in the neonatal population regarding consequences of selenium deficiency or toxicity, accurate monitoring of levels, and proper enteral and parental dosages. This review highlights the role of selenium as it relates to the optimal function of antioxidant systems in extremely preterm infants in order to highlight the gaps in knowledge as it relates to the pathogenesis and prevention of morbidities in this population.