Altered neurodevelopmental DNA methylation status after fetal growth restriction with brain-sparing

Association between chest-to-head circumference ratio at birth and childhood neurodevelopment: the Japan Environment and Children's Study

Children born growth-restricted are well recognized to be at an increased risk of poor neurodevelopmental outcomes. This prospective study examined the influence of chest-to-head circumference ratio at birth on neurodevelopment in the first three years among children enrolled in the Japan Environment and Children's Study. We analyzed information of 84,311 children (43,217 boys, 41,094 girls). Children were divided into low, normal, and high chest-to-head circumference ratio groups. Neurodevelopment was assessed every six months (from 6 months to 3 years) using the Ages and Stages Questionnaire (Japanese translation), with delays defined as scores below 2 standard deviations from the mean. Additionally, we evaluated the contributions of chest and head circumference to the observed association. Linear mixed-effect regression revealed increased risk of delays in communication, gross motor, fine motor, problem-solving, and personal-social skills in the low-ratio group compared to the normal-ratio group. Adjusted risk ratios were in the range of 1.14 - 1.39 in boys and 1.16 - 1.37 in girls, with no such increase observed in the high-ratio group. The heightened risk in the low-ratio group was likely associated with a relatively narrow chest rather than a large head. The area under the ROC curves in predicting any developmental delay at three years for newborn measurements ranged from 0.513 to 0.526 in boys and 0.509 to 0.531 in girls. These findings suggest that a low chest-to-head circumference ratio may indicate children who are at risk for neurodevelopmental deficits. However, the ability to predict poor neurodevelopmental outcomes at three years of age is limited.

DNA Methylation, Inflammation, and Neurobehavior in Preterm Infants

Objectives: Inflammation contributes to disparate neurodevelopmental outcomes between preterm and term-born infants. In this context, DNA methylation may contribute to inflammation by affecting gene expression. Brain-derived neurotrophic factor (BDNF) and nuclear factor-kappa-B-inhibitor alpha (NFKBIA) are important genes for targeted DNA methylation analysis. The aims of this study were to (1) identify associations between inflammatory factors and BDNF and NFKBIA methylation, and (2) identify associations between BDNF and NFKBIA methylation and early neurobehavior in preterm infants. Methods: In a longitudinal cohort study of preterm infants born 28-31 weeks gestational age, blood samples were collected weekly for the quantification of inflammatory factors. We extracted DNA from saliva samples and quantified methylation of six BDNF cytosine-phosphate-guanine (CpG) sites and five NFKBIA CpG sites. Neurobehavior was assessed using the Neurobehavioral Assessment of the Preterm Infant. Results: Sixty-five infants were included in the analysis. In females, inflammatory factors were positively associated with BDNF methylation of most CpG sites. Interleukin-1 receptor antagonist was negatively associated with NFKBIA methylation at two CpG sites. In males, interleukin-6 was negatively associated with BDNF and NFKBIA methylation at most CpG sites. In females, BDNF methylation at two sites was inversely associated with motor performance. In males, NFKBIA methylation at one site was inversely associated with motor performance. Conclusion: This study provides evidence for the relationship between inflammation and neurobehavior in preterm infants, working mechanistically through DNA methylation. The finding of a difference between males and females suggests that female infants are potentially more vulnerable to inflammation and warrants future study.

Does placental VEGF-A protein expression predict early neurological outcome of neonates from FGR complicated pregnancies?

OBJECTIVES

Fetal hypoxia due to placental dysfunction is the hallmark of fetal growth restriction (FGR). Preferential perfusion of the brain (brain-sparing effect), as a part of physiological placental cardiovascular compensatory mechanisms to hypoxia, in FGR was reported. Therefore, the correlation between vascular endothelial growth factor A (VEGF-A) protein expression in the FGR placentas and newborns' early neurological outcome was examined.

METHODS

This study included 50 women with FGR complicated pregnancies and 30 uneventful pregnancies. Fetal hemodynamic parameters, neonatal acid-base status after delivery, placental pathohistology and VEGF-A expression were followed. Early neonatal morphological brain evaluation by ultrasound and functional evaluation of neurological status by Amiel - Tison Neurological Assessment at Term (ATNAT) were performed.

RESULTS

VEGF-A protein expression level was significantly higher in the FGR placentas than normal term placentas (Fisher-Freeman-Halton's test, p≤0.001). No statistically significant correlation between placental VEGF-A expression and different prenatal and postnatal parameters was noticed. Whereas the alteration of an early neurological status assessed by ATNAT was found in 58 % of FGR newborns, morphological brain changes evaluated by UZV was noticed in 48 % of cases. No association between the level of placental VEGF-A expression and the early neurological deficits was found.

CONCLUSIONS

As far as we know this is the first study of a possible connection between VEGF-A protein expression in the FGR placentas and neonates' early neurological outcomes. The lack of correlation between the FGR placental VEGF-A expression and neonates' neurological outcome could indicate that optimal early neurodevelopment may take place due to compensatory mechanism not related to placental VEGF-A expression.

Cerebral Hypoxia-Induced Molecular Alterations and Their Impact on the Physiology of Neurons and Dendritic Spines: A Comprehensive Review

This article comprehensively reviews how cerebral hypoxia impacts the physiological state of neurons and dendritic spines through a series of molecular changes, and explores the causal relationship between these changes and neuronal functional impairment. As a severe pathological condition, cerebral hypoxia can significantly alter the morphology and function of neurons and dendritic spines. Specifically, dendritic spines, being the critical structures for neurons to receive information, undergo changes such as a reduction in number and morphological abnormalities under hypoxic conditions. These alterations further affect synaptic function, leading to neurotransmission disorders. This article delves into the roles of molecular pathways like MAPK, AMPA receptors, NMDA receptors, and BDNF in the hypoxia-induced changes in neurons and dendritic spines, and outlines current treatment strategies. Neurons are particularly sensitive to cerebral hypoxia, with their apical dendrites being vulnerable to damage, thereby affecting cognitive function. Additionally, astrocytes and microglia play an indispensable role in protecting neuronal and synaptic structures, regulating their normal functions, and contributing to the repair process following injury. These studies not only contribute to understanding the pathogenesis of related neurological diseases but also provide important insights for developing novel therapeutic strategies. Future research should further focus on the dynamic changes in neurons and dendritic spines under hypoxic conditions and their intrinsic connections with cognitive function.

Congenital heart defects in monochorionic twin pregnancy complicated by selective fetal growth restriction

OBJECTIVES

To evaluate the prevalence, subtypes and postnatal outcomes of congenital heart defects (CHD) in a cohort of monochorionic diamniotic (MCDA) twin pregnancies complicated by selective fetal growth restriction (sFGR), and to compare this population with a cohort of uncomplicated MCDA pregnancies evaluated during the same period.

METHODS

This was a retrospective analysis of all consecutive MCDA pregnancies referred between 2009 and 2018, including those complicated by sFGR (Group A) and those without complications (Group B). All neonates delivered in our center were screened for CHD before discharge. Discharge letters for all those delivered elsewhere were retrieved. Pregnancies with complications other than sFGR and those without perinatal follow-up were excluded. Pregnancies in Group A were divided into three types according to the Gratacós system of sFGR classification.

RESULTS

A total of 870 MCDA twin pregnancies were included: 296 in Group A and 574 in Group B. In Group A, the prevalence of CHD was 3.7% (22/592 twins), with no significant difference in CHD frequency between the three types of sFGR (Type I, 3.7%; Type II, 3.2%; Type III, 4.2%; P = 0.55). Of four Type-III sFGR pregnancies with CHD, one had pulmonary stenosis (PS) in the larger twin and isolated coarctation of the aorta in the smaller cotwin, and three had PS in the larger twin only. No Type-III sFGR pregnancies in which only the smaller twin was affected by CHD were observed. Of 11 CHD cases in the larger twin, 10 (91%) were right ventricular outflow tract abnormalities (RVOTA), and one (9%) was a ventricular septal defect. In the smaller twins, 11 cases of CHD were observed, covering a broad spectrum of cardiac abnormalities. In Group B, the CHD prevalence was 1.1% (13/1148 twins), which was similar to that in the general population, according to the EUROCAT registry for the same period and geographical area of the study (0.96%; P = 0.579). The CHD prevalence was significantly higher in Group A compared with Group B (3.7% vs 1.1%; P = 0.0002; odds ratio, 3.57 (95% CI, 1.78-7.22)). In all pregnancies with CHD in the study population, the anomaly was discordant.

CONCLUSIONS

In MCDA twin pregnancy, sFGR was associated with a three-fold higher prevalence of CHD. Women with such pregnancies should be referred to a tertiary care hospital for pre- and postnatal cardiac evaluation, treatment and long-term follow-up. In larger twins, the only major CHD observed was RVOTA, while a broad spectrum of CHD was noted in smaller twins. The higher risk of CHD in MCDA pregnancies appears to be due to the typical complications of the monochorionic pregnancy, rather than to the monochorionic nature of the pregnancy itself. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Helicid Improves Lipopolysaccharide-Induced Apoptosis of C6 Cells by Regulating SH2D5 DNA Methylation via the CytC/Caspase9/Caspase3 Signaling Pathway

DNA methylation is reportedly associated with stress responses and depression. Treatment with antidepressants can regulate DNA methylation and, subsequently, gene expression in the hippocampus. Hence, DNA methylation is a potential target for treatment of depression. Screening of high-throughput data of a rat model of chronic unpredictable mild stress revealed relatively low expression of SH2 domain-containing 5 (SH2D5). SH2D5 can be overexpressed by treatment with helicid. Therefore, in order to further explore the role of SH2D5 in depression and whether helicid mediates the DNA methylation of SH2D5 as a potential antidepressant role, SH2D5 was overexpressed in C6 cells as a lipopolysaccharides (LPS)-induced model of depression. The expression levels of Bax, Bcl-2, Bad, and Daxx, and changes to the CytC/caspase9/caspase3 signal pathway were detected by qRT-PCR and Western blot analyses. After treatment with helicid or silencing of SH2D5, the above indices were detected. The results showed that helicid regulated the CytC/caspase9/caspase3 signaling pathway and improved the apoptosis indices of C6 cells through the overexpression of SH2D5. Interestingly, silencing of SH2D5 reversed the effects of helicid on the above indices. Then, in order to study the underlying mechanism, the cells were administered to helicid or 5-aza-2'-deoxycytidine (5-AzaD) and expression of SH2D5 was detected by qRT-PCR and Western blot analyses, while to assess the DNA methylation level of SH2D5 using bisulfite sequencing/PCR. The results showed that SH2D5 was hypermethylated with low expression in LPS-induced C6 cells, which was reversed by helicid and 5-AzaD. These results suggest that helicid may affect the CytC/caspase9/caspase3 apoptosis signaling pathway and improve the apoptosis indices by mediating DNA methylation of SH2D5.

Differential Placental DNA Methylation of NR3C1 in Extremely Preterm Infants With Poorer Neurological Functioning

BACKGROUND

Understanding underlying mechanisms of neurodevelopmental impairment following preterm birth may enhance opportunities for targeted interventions. We aimed to assess whether placental DNA methylation of selected genes affected early neurological functioning in preterm infants.

METHODS

We included 43 infants, with gestational age <30 weeks and/or birth weight <1,000 g and placental samples at birth. We selected genes based on their associations with several prenatal conditions that may be related to poor neurodevelopmental outcomes. We determined DNA methylation using pyrosequencing, and neurological functioning at 3 months post-term using Prechtl's General Movement Assessment, including the Motor Optimality Score-Revised (MOS-R).

RESULTS

Twenty-four infants had atypical MOS-R, 19 infants had near-optimal MOS-R. We identified differences in average methylation of NR3C1 (encoding for the glucocorticoid receptor) [3.3% (95%-CI: 2.4%-3.9%) for near-optimal vs. 2.3% (95%-CI: 1.7%-3.0%), p = 0.008 for atypical], and at three of the five individual CpG-sites. For EPO, SLC6A3, TLR4, VEGFA, LEP and HSD11B2 we found no differences between the groups.

CONCLUSION

Hypomethylation of NR3C1 in placental tissue is associated with poorer neurological functioning at 3 months post-term in extremely preterm infants. Alleviating stress during pregnancy and its impact on preterm infants and their neurodevelopmental outcomes should be further investigated.