Inflammatory and oxidative stress airway markers in premature newborns of hypertensive mothers

Oxidative Stress Levels and Dynamic Thiol-Disulfide Balance in Preterm Newborns with Bronchopulmonary Dysplasia

OBJECTIVE

The aim of this study was to assess the oxidative stress (OS) levels and dynamic thiol-disulfide balance in preterm newborns with bronchopulmonary dysplasia (BPD).

METHODS

This prospective study included newborns separated into 2 groups, those with BPD (case) or without BPD (control). The 2 groups were compared by clinical and laboratory findings. The OS parameters total oxidant status (TOS), total antioxidant status (TAS), OS index (OSI), native thiol (NT), and total thiol were measured within the first day after birth. Oxygen requirements were measured using the fraction of inspired oxygen (FIO2) recorded in the first hour after birth/admission and the average FIO2 within 28 days of the birth.

RESULTS

Infants diagnosed with BPD had a significantly lower gestational age and birth weight and a lower 5-min Apgar score (P < .05). Infants with BPD also had a higher rate of respiratory distress syndrome, rate of use of surfactant therapy, duration of ventilation therapy, and duration of hospital stay compared with control (P = .001, P = .001, P = .001, and P = .001, respectively). Plasma TAS and NT levels of newborns with BPD were significantly lower than newborns without BPD (P < .05). In the BPD group, plasma TOS and OSI levels were significantly higher than in the control group.

CONCLUSION

We found that OS was increased in newborns with BPD. The clinical significance of this study will provide the clinician with a different perspective on BPD by determining the dynamic thiol disulfide balance.

Endothelial dysfunction in preterm infants: The hidden legacy of uteroplacental pathologies

Millions of infants are born prematurely every year worldwide. Prematurity, particularly at lower gestational ages, is associated with high mortality and morbidity and is a significant global health burden. Pregnancy complications and preterm birth syndrome strongly impact neonatal clinical phenotypes and outcomes. The vascular endothelium is a pivotal regulator of fetal growth and development. In recent years, the key role of uteroplacental pathologies impairing endothelial homeostasis is emerging. Conditions leading to very and extremely preterm birth can be classified into two main pathophysiological patterns or endotypes: infection/inflammation and dysfunctional placentation. The first is frequently related to chorioamnionitis, whereas the second is commonly associated with hypertensive disorders of pregnancy and fetal growth restriction. The nature, timing, and extent of prenatal noxa may alter fetal and neonatal endothelial phenotype and functions. Changes in the luminal surface, oxidative stress, growth factors imbalance, and dysregulation of permeability and vascular tone are the leading causes of endothelial dysfunction in preterm infants. However, the available evidence regarding endothelial physiology and damage is limited in neonates compared to adults. Herein, we discuss the current knowledge on endothelial dysfunction in the infectious/inflammatory and dysfunctional placentation endotypes of prematurity, summarizing their molecular features, available biomarkers, and clinical impact. Furthermore, knowledge gaps, shadows, and future research perspectives are highlighted.

The Role of Antioxidants Supplementation in Clinical Practice: Focus on Cardiovascular Risk Factors

Oxidative stress may be defined as an imbalance between reactive oxygen species (ROS) and the antioxidant system to counteract or detoxify these potentially damaging molecules. This phenomenon is a common feature of many human disorders, such as cardiovascular disease. Many of the risk factors, including smoking, hypertension, hypercholesterolemia, diabetes, and obesity, are associated with an increased risk of developing cardiovascular disease, involving an elevated oxidative stress burden (either due to enhanced ROS production or decreased antioxidant protection). There are many therapeutic options to treat oxidative stress-associated cardiovascular diseases. Numerous studies have focused on the utility of antioxidant supplementation. However, whether antioxidant supplementation has any preventive and/or therapeutic value in cardiovascular pathology is still a matter of debate. In this review, we provide a detailed description of oxidative stress biomarkers in several cardiovascular risk factors. We also discuss the clinical implications of the supplementation with several classes of antioxidants, and their potential role for protecting against cardiovascular risk factors.

Non-invasive assessment of oxidative stress in preterm infants

Preterm newborns have an immature antioxidant defense system and are especially susceptible to oxidative stress. Resuscitation, mechanical ventilation, intermittent hypoxia and apneic episodes require frequently oxygen supplementation which leads to oxidative stress in preterm newborns. The consequences of oxidative damage are increased short and long-term morbidities, neurodevelopmental impairment and increased mortality. Oxidative stress biomarkers are determined in blood samples from preterm children during their stay in neonatal intensive care units especially for research purposes. However, there is a tendency towards reducing invasive and painful techniques in the NICU (Neonatal Intensive Care Unit) and avoiding excessive blood extractions procedures. In this paper, it has been described some studies that employed non-invasive samples to determine oxidative stress biomarkers form preterm infants in order to perform a close monitoring biomarker with a significant greater predictive value. Among these methods we describe a previously developed and validated high-performance liquid chromatography tandem mass spectrometry method that allow to accurately determine the most reliable biomarkers in biofluids, which are non-invasively and painlessly obtained.

PRO-OXIDANTS AND ANTIOXIDANTS IN RETINOPATHY OF PREMATURITY

- Premature infants are susceptible to oxidative stress that causes neonatal disease such as retinopathy of prematurity (ROP). Oxidative stress is an imbalance between the production of pro-oxidants and the ability of the body to detoxify their harmful effects by antioxidants. The proliferative phase 2 ROP occurs at around 33^rd postmenstrual week (pmw). The purpose of our study was to evaluate the pro-oxidant/antioxidant status in preterm infants at 33^rd pmw. The study included 59 premature infants. ROP was classified according to the International Classification of Retinopathy of Prematurity. Total oxidative status (TOS), total antioxidant status (TAS), malondialdehyde (MDA) and paraoxonase 1 (PON1) activity were determined spectrophotometrically. The values of the pro-oxidants TOS and MDA were significantly higher in infants with ROP as compared to infants without ROP (p<0.05 both). There were no significant differences in the values of TAS and PON1 between the infants with and without ROP. According to study results, TOS and MDA are good markers of oxidative stress, whereas TAS and PON1 activity are unreliable in assessing antioxidant protection.

Sex-Specificity of Oxidative Stress in Newborns Leading to a Personalized Antioxidant Nutritive Strategy

Oxidative stress is a critical process that triggers several diseases observed in premature infants. Growing recognition of the detriment of oxidative stress in newborns warrants the use of an antioxidant strategy that is likely to be nutritional in order to restore redox homeostasis. It appears essential to have a personalized approach that will take into account the age of gestation at birth and the sex of the infant. However, the link between sex and oxidative stress remains unclear. The aim of this study was to find a common denominator explaining the discrepancy between studies related to sex-specific effects of oxidative stress. Results highlight a specificity of sex in the levels of oxidative stress markers linked to the metabolism of glutathione, as measured in the intracellular compartments. Levels of all sex-dependent oxidative stress markers are greater and markers associated to a better antioxidant defense are lower in boys compared to girls during the neonatal period. This sex-specific discrepancy is likely to be related to estrogen metabolism, which is more active in baby-girls and promotes the activation of glutathione metabolism. Conclusion: our observations suggest that nutritive antioxidant strategies need to target glutathione metabolism and, therefore, should be personalized considering, among others, the sex specificity.