Molecular Indicators of Blood-Brain Barrier Breakdown and Neuronal Injury in Pregnancy Complicated by Fetal Growth Restriction

Neural and Onconeural Autoantibodies and Blood-Brain Barrier Disruption Markers in Patients Undergoing Radiotherapy for High-Grade Primary Brain Tumour

Radiotherapy (RT) plays a key role in brain tumours but can negatively impact functional outcomes and quality of life. The aim of this study was to analyse anti-neural and onconeural autoantibodies and markers of blood-brain barrier (BBB) disruption in patients with primary brain cancer undergoing RT.

MATERIALS AND METHODS

A prospective study was conducted on 45 patients with a brain tumour scheduled for intensity-modulated radiotherapy. Assessments were performed at baseline, post-RT, and at three months. We measured serum levels of BBB disruption biomarkers and anti-neural, onconeural, and organ-specific antibodies.

RESULTS

Antibodies against nucleosome antigens and neuronal surface antigens were detected in 85% and 3% of cases, respectively; anti-neural and onconeural antibodies were observed in 47% and 5.8%. In 44% patients, ≥2 antibody types were detected. No significant changes in BBB biomarkers were observed.

CONCLUSION

The findings of this study show that a humoral immune response is common in patients undergoing RT for brain cancer. This response appears to be non-organ specific but rather directed against nucleosome antigens, but onconeural antibodies were uncommon, suggesting a low risk of a neurological paraneoplastic syndrome. Our data suggested that radiotherapy may not affect BBB integrity, but larger studies are needed to better characterise the pathophysiological effects of RT.

Early changes in S100B maternal blood levels can predict fetal intrauterine growth restriction

OBJECTIVES

Intrauterine growth restriction (IUGR) represents one of the main causes of perinatal mortality and morbidity. Nowadays, IUGR early diagnosis is mandatory in order to limit the occurrence of multiorgan failure, especially the brain. Therefore, we investigated whether longitudinal S100B assessment in maternal blood could be a trustable predictor of IUGR.

METHODS

We conducted a prospective study in 480 pregnancies (IUGR: n=40; small for gestational age, SGA: n=40; controls: n=400) in whom S100B was measured at three predetermined monitoring time-points (T1: 8-18 GA; T2: 19-23 GA; T3: 24-28 GA).

RESULTS

Lower S100B in IUGR fetuses than SGA and controls (p<0.05, for all) at T1-T3. Receiver operating characteristic curve showed that S100B at T1 was the best predictor of IUGR (sensitivity: 100 %; specificity: 81.4 %) than T2, T3.

CONCLUSIONS

The early lower S100B concentration in pregnant women lately complicated by IUGR support the notion that non-invasive early IUGR diagnosis and monitoring is becoming feasible. Results open the way to further studies aimed at diagnosing and monitoring fetal/maternal diseases at earliest time.

The blood-brain barrier, a key bridge to treat neurodegenerative diseases

As a highly selective and semi-permeable barrier that separates the circulating blood from the brain and central nervous system (CNS), the blood-brain barrier (BBB) plays a critical role in the onset and treatment of neurodegenerative diseases (NDs). To delay or reverse the NDs progression, the dysfunction of BBB should be improved to protect the brain from harmful substances. Simultaneously, a highly efficient drug delivery across the BBB is indispensable. Here, we summarized several methods to improve BBB dysfunction in NDs, including knocking out risk geneAPOE4, regulating circadian rhythms, restoring the gut microenvironment, and activating the Wnt/β-catenin signaling pathway. Then we discussed the advances in BBB penetration techniques, such as transient BBB opening, carrier-mediated drug delivery, and nasal administration, which facilitates drug delivery across the BBB. Furthermore, various in vivo and in vitro BBB models and research methods related to NDs are reviewed. Based on the current research progress, the treatment of NDs in the long term should prioritize the integrity of the BBB. However, a treatment approach that combines precise control of transient BBB permeability and non-invasive targeted BBB drug delivery holds profound significance in improving treatment effectiveness, safety, and clinical feasibility during drug therapy. This review involves the cross application of biology, materials science, imaging, engineering and other disciplines in the field of BBB, aiming to provide multi-dimensional research directions and clinical ideas for the treating NDs.

Pathogenesis of Pregnancy-Related Complications

In this special edition (closed on 31 October 2022), 4 reviews, 13 original papers, 1 communication, and 1 case report are published [...]

Does the Blood-Brain Barrier Integrity Change in Regard to the Onset of Fetal Growth Restriction?

The aim of the study was to determine whether early-onset and late-onset fetal growth restriction (FGR) differentially affects the blood-brain barrier integrity. Furthermore, the purpose of the study was to investigate the relationship between the blood-brain barrier breakdown and neurological disorders in FGR newborns. To evaluate the serum tight junction (TJ) proteins and the placental TJ proteins expression, an ELISA method was used. A significant difference in serum OCLN concentrations was noticed in pregnancies complicated by the early-onset FGR, in relation to the intraventricular hemorrhage (IVH) occurrence in newborns. No significant differences in concentrations of the NR1 subunit of the N-methyl-d-aspartate receptor (NR1), nucleoside diphosphate kinase A (NME1), S100 calcium-binding protein B (S100B), occludin (OCLN), claudin-5 (CLN5), zonula occludens-1 (zo-1), the CLN5/zo-1 ratio, and the placental expression of OCLN, CLN5, claudin-4 (CLN4), zo-1 were noticed between groups. The early-onset FGR was associated with a higher release of NME1 into the maternal circulation in relation to the brain-sparing effect and premature delivery. Additionally, in late-onset FGR, the higher release of the S100B into the maternal serum in regard to fetal distress was observed. Furthermore, there was a higher release of zo-1 into the maternal circulation in relation to newborns' moderate acidosis in late-onset FGR. Blood-brain barrier disintegration is not dependent on pregnancy advancement at the time of FGR diagnosis. NME1 may serve as a biomarker useful in the prediction of fetal circulatory centralization and extremely low birth weight in pregnancies complicated by the early-onset FGR. Moreover, the serum zo-1 concentration may have prognostic value for moderate neonatal acidosis in late-onset FGR pregnancies.

Regulators involved in trophoblast syncytialization in the placenta of intrauterine growth restriction

Placental dysfunction refers to the insufficiency of placental perfusion and chronic hypoxia during early pregnancy, which impairs placental function and causes inadequate supply of oxygen and nutrients to the fetus, affecting fetal development and health. Fetal intrauterine growth restriction, one of the most common outcomes of pregnancy-induced hypertensions, can be caused by placental dysfunction, resulting from deficient trophoblast syncytialization, inadequate trophoblast invasion and impaired vascular remodeling. During placental development, cytotrophoblasts fuse to form a multinucleated syncytia barrier, which supplies oxygen and nutrients to meet the metabolic demands for fetal growth. A reduction in the cell fusion index and the number of nuclei in the syncytiotrophoblast are found in the placentas of pregnancies complicated by IUGR, suggesting that the occurrence of IUGR may be related to inadequate trophoblast syncytialization. During the multiple processes of trophoblasts syncytialization, specific proteins and several signaling pathways are involved in coordinating these events and regulating placental function. In addition, epigenetic modifications, cell metabolism, senescence, and autophagy are also involved. Study findings have indicated several abnormally expressed syncytialization-related proteins and signaling pathways in the placentas of pregnancies complicated by IUGR, suggesting that these elements may play a crucial role in the occurrence of IUGR. In this review, we discuss the regulators of trophoblast syncytialization and their abnormal expression in the placentas of pregnancies complicated by IUGR.