Total oxidant, antioxidant, and paraoxonase levels in babies born to pre-eclamptic mothers

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.

Fetal High-Density Lipoproteins: Current Knowledge on Particle Metabolism, Composition and Function in Health and Disease

Cholesterol and other lipids carried by lipoproteins play an indispensable role in fetal development. Recent evidence suggests that maternally derived high-density lipoprotein (HDL) differs from fetal HDL with respect to its proteome, size, and function. Compared to the HDL of adults, fetal HDL is the major carrier of cholesterol and has a unique composition that implies other physiological functions. Fetal HDL is enriched in apolipoprotein E, which binds with high affinity to the low-density lipoprotein receptor. Thus, it appears that a primary function of fetal HDL is the transport of cholesterol to tissues as is accomplished by low-density lipoproteins in adults. The fetal HDL-associated bioactive sphingolipid sphingosine-1-phosphate shows strong vasoprotective effects at the fetoplacental vasculature. Moreover, lipoprotein-associated phospholipase A2 carried by fetal-HDL exerts anti-oxidative and athero-protective functions on the fetoplacental endothelium. Notably, the mass and activity of HDL-associated paraoxonase 1 are about 5-fold lower in the fetus, accompanied by an attenuation of anti-oxidative activity of fetal HDL. Cholesteryl ester transfer protein activity is reduced in fetal circulation despite similar amounts of the enzyme in maternal and fetal serum. This review summarizes the current knowledge on fetal HDL as a potential vasoprotective lipoprotein during fetal development. We also provide an overview of whether and how the protective functionalities of HDL are impaired in pregnancy-related syndromes such as pre-eclampsia or gestational diabetes mellitus.

Total antioxidant status as marker of oxidative stress in infants with intrauterine growth restriction

Aim: The aim of this study is to identify correlations between total antioxidant status values of mothers and their infants and compare these values in accordance to the presence or absence of intrauterine growth restriction.

Material and methods: This is a prospective, comparative study performed over a period of 3 years on a number of 52 infants and their mothers. Thirty-six of them had intrauterine growth restriction and 16 were appropriate for their gestational age and were used for comparative purposes. General information regarding the mother, infant and pregnancy were recorded. In addition, total antioxidant status was assessed from blood samples, taken right before delivery from mothers and from the cord blood in infants.

Results: We found significant differences between total antioxidant status both between mothers and neonates with IUGR (intrauterine growth restriction) versus without IUGR (p=0.018, and p<0.001, respectively). In addition, in both groups, there was a significant direct correlation between maternal and neonatal values of serum total antioxidant status (TAS) (p<0.001).

In conclusion, we can say that TAS values, as an important marker of the oxidative status of patients, are correlated with the presence of IUGR and values recorded from blood samples of the mother may be predictive for the oxidative status of the infant, thus of IUGR.

Oxidative injury of the pulmonary circulation in the perinatal period: Short- and long-term consequences for the human cardiopulmonary system

Development of the pulmonary circulation is a complex process with a spatial pattern that is tightly controlled. This process is vulnerable for disruption by various events in the prenatal and early postnatal periods. Disruption of normal pulmonary vascular development leads to abnormal structure and function of the lung vasculature, causing neonatal pulmonary vascular diseases. Premature babies are especially at risk of the development of these diseases, including persistent pulmonary hypertension and bronchopulmonary dysplasia. Reactive oxygen species play a key role in the pathogenesis of neonatal pulmonary vascular diseases and can be caused by hyperoxia, mechanical ventilation, hypoxia, and inflammation. Besides the well-established short-term consequences, exposure of the developing lung to injurious stimuli in the perinatal period, including oxidative stress, may also contribute to the development of pulmonary vascular diseases later in life, through so-called "fetal or perinatal programming." Because of these long-term consequences, it is important to develop a follow-up program tailored to adolescent survivors of neonatal pulmonary vascular diseases, aimed at early detection of adult pulmonary vascular diseases, and thereby opening the possibility of early intervention and interfering with disease progression. This review focuses on pathophysiologic events in the perinatal period that have been shown to disrupt human normal pulmonary vascular development, leading to neonatal pulmonary vascular diseases that can extend even into adulthood. This knowledge may be particularly important for ex-premature adults who are at risk of the long-term consequences of pulmonary vascular diseases, thereby contributing disproportionately to the burden of adult cardiovascular disease in the future.

Serum ischemia-modified albumin and oxidized LDL in cord blood and serum of neonates born to pre-eclamptic mothers

BACKGROUND

We investigated oxidized low-density lipoprotein (OxLDL) and ischemia-modified albumin (IMA) in cord blood and neonatal blood of 7-day-old neonates born to pre-eclamptic and normotensive healthy mothers.

METHODS

The study was performed on 30 neonates born to pre-eclamptic and 20 neonates born to normotensive mothers. IMA and OxLDL were determined on spectrophotometry and ELISA, respectively.

RESULTS

IMA in cord blood was higher in the pre-eclamptic group as compared with the normotensive group, but the difference between the groups was not significant. IMA in neonate venous blood was significantly higher in the pre-eclamptic group than in the normotensive group (P < 0.001). OxLDL in both cord blood and in neonate venous blood was significantly higher in the pre-eclamptic group compared with the normotensive group (P < 0.001). IMA and OxLDL were significantly decreased after delivery in both groups.

CONCLUSIONS

Significantly increased cord blood OxLDL and significantly increased OxLDL and IMA 7 days after birth in neonates born to pre-eclamptic mothers might be an indicator of increased oxidative stress in pre-eclampsia.

Paraoxonase 1 lactonase activity and distribution in the HDL subclasses in the cord blood

OBJECTIVES

Paraoxonase 1 (PON1) is a lactonase with important antioxidant and immunoprotective properties. We hypothesized that PON1 lactonase activity, PON1, and high-density lipoprotein (HDL) subclasses distribution are different in neonates than in adults.

MATERIAL AND METHODS

We studied 83 healthy term neonates (34 males and 49 females) who were born by spontaneous, uncomplicated vaginal delivery. The study also included 17 paired maternal blood samples as well as 20 non-pregnant women collected for comparison. Total and free PON1 lactonase and arylesterase activity, HDL subclasses, PON1, and apolipoprotein distribution in the subclasses were assayed.

RESULTS

PON1 arylesterase activity in the cord blood represented 37% ± 4 of the maternal activity, whereas the PON1 lactonase activity amounted to only 23% ± 5 of the maternal activity. The free arylesterase and lactonase activities were higher in the cord blood by 16 and 36%, respectively. There is a 65% lower HDL2b PON1 in the cord blood than in the maternal serum. When the Lipoprint HDL subclasses were assayed, the neonates showed a larger content (52% higher) of very large HDL as well as a characteristic peak in the middle-sized HDL5 which is unremarkable in the mothers.

CONCLUSION

The novel findings of this study are that the neonates have lower PON1 lactonase activity, higher free PON1, different distributions of PON1 in the HDL subclasses as compared with their mother and adults as well as a distinctive HDL subclass lipid profile. Our data also suggest that the neonate HDL is enriched with an intermediate-sized (and/or less charged HDL) that is also rich in active PON1.