New insights into the pathogenesis of perinatal hypoxic-ischemic brain injury

Rehabilitation Intervention Is Associated With Improved Neurodevelopment and Modulation of Inflammatory Molecules in Children With Cerebral Palsy

AIM

To evaluate the effects of systematic rehabilitation on both the neuropsychomotor development, and on the peripheral response from immunological and neuroplastic mediators in children with cerebral palsy.

METHODS

This is a prospective cohort study with 90 children with cerebral palsy at 18 months of age. Sixty children received rehabilitation for 6 months, and they were compared to 30 children that were placed in the waiting list. Peripheral biomarkers and neuropsychomotor parameters were compared between the Rehab vs the Nonrehab groups at baseline and at 6 months.

RESULTS

Results showed higher Bayley III scores in the Rehab group, with significant differences in inflammatory and neurotrophic biomarkers between groups. Rehabilitation was associated to decreased levels of IL-12p70, IL-6, IL-1β, CXCL8 IL-8, and CXCL9/MIG and increased levels of BDNF and GDNF. Nonrehab children had stable immune molecule levels but decreased BDNF levels over time.

CONCLUSION

Rehabilitation improved neurodevelopment parameters and modulated levels of inflammatory (↓) and neurotrophic (↑) biomarkers.

Hydrogen-rich saline regulates NLRP3 inflammasome activation in sepsis-associated encephalopathy rat model

Sepsis-associated encephalopathy (SAE) is characterised by long-term cognitive impairment and psychiatric illness in sepsis survivors, associated with increased morbidity and mortality. There is a lack of effective therapeutics for SAE. Molecular hydrogen (H2) plays multiple roles in septic diseases by regulating neuroinflammation, reducing oxidative stress parameters, regulating signalling pathways, improving mitochondrial dysfunction, and regulating astrocyte and microglia activation. Here we report the protective effect of hydrogen-rich saline in the juvenile SAE rat model and its possible underlying mechanisms. Rats were injected intraperitoneally with lipopolysaccharide at a dose of 5 mg/kg to induce sepsis; Hydrogen-rich saline (HRS) was administered 1 h after LPS induction at a dose of 5 ml/kg and nigericin at 1 mg/kg 1 h before LPS injection. H&E staining for neuronal damage, TUNEL assay for detection of apoptotic cells, immunofluorescence, ELISA protocol for inflammatory cytokines and 8-OHdG determination and western blot analysis to determine the effect of HRS in LPS-induced septic rats. Rats treated with HRS showed decreased TNF-α and IL-1β expression levels. HRS treatment enhanced the activities of antioxidant enzymes (SOD, CAT and GPX) and decreased MDA and MPO activities. The number of MMP-9 and NLRP3 positive immunoreactivity cells decreased in the HRS-treated group. Subsequently, GFAP, IBA-1 and CD86 immunoreactivity were reduced, and CD206 increased after HRS treatment. 8-OHdG expression was decreased in the HRS-treated rats. Western blot analysis showed decreased NLRP3, ASC, caspase-1, MMP-2/9, TLR4 and Bax protein levels after HRS treatment, while Bcl-2 expression increased after HRS treatment. These data demonstrated that HRS attenuated neuroinflammation, NLRP3 inflammasome activation, neuronal injury, and mitochondrial damage via NLRP3/Caspase-1/TLR4 signalling in the juvenile rat model, making it a potential therapeutic agent in the treatment of paediatric SAE.

Paediatric sepsis-associated encephalopathy (SAE): a comprehensive review

Sepsis-associated encephalopathy (SAE) is one of the most common types of organ dysfunction without overt central nervous system (CNS) infection. It is associated with higher mortality, low quality of life, and long-term neurological sequelae, its mortality in patients diagnosed with sepsis, progressing to SAE, is 9% to 76%. The pathophysiology of SAE is still unknown, but its mechanisms are well elaborated, including oxidative stress, increased cytokines and proinflammatory factors levels, disturbances in the cerebral circulation, changes in blood-brain barrier permeability, injury to the brain's vascular endothelium, altered levels of neurotransmitters, changes in amino acid levels, dysfunction of cerebral microvascular cells, mitochondria dysfunction, activation of microglia and astrocytes, and neuronal death. The diagnosis of SAE involves excluding direct CNS infection or other types of encephalopathies, which might hinder its early detection and appropriate implementation of management protocols, especially in paediatric patients where only a few cases have been reported in the literature. The most commonly applied diagnostic tools include electroencephalography, neurological imaging, and biomarker detection. SAE treatment mainly focuses on managing underlying conditions and using antibiotics and supportive therapy. In contrast, sedative medication is used judiciously to treat those showing features such as agitation. The most widely used medication is dexmedetomidine which is neuroprotective by inhibiting neuronal apoptosis and reducing a sepsis-associated inflammatory response, resulting in improved short-term mortality and shorter time on a ventilator. Other agents, such as dexamethasone, melatonin, and magnesium, are also being explored in vivo and ex vivo with encouraging results. Managing modifiable factors associated with SAE is crucial in improving generalised neurological outcomes. From those mentioned above, there are still only a few experimentation models of paediatric SAE and its treatment strategies. Extrapolation of adult SAE models is challenging because of the evolving brain and technical complexity of the model being investigated. Here, we reviewed the current understanding of paediatric SAE, its pathophysiological mechanisms, diagnostic methods, therapeutic interventions, and potential emerging neuroprotective agents.

A systematic review of noninflammatory cerebrospinal fluid biomarkers for clinical outcome in neonates with perinatal hypoxic brain injury that could be biologically significant

Neonatal encephalopathy (NE) that purportedly arises from hypoxia-ischemia is labeled hypoxic-ischemic encephalopathy (HIE). Perinatal asphyxia is a clinical syndrome involving acidosis, a low Apgar score and the need for resuscitation in the delivery room; asphyxia alerts one to the possibility of NE. In the present systematic review, we focused on the noninflammatory biomarkers in cerebrospinal fluid (CSF) that are involved in the development of possible brain injury in asphyxia or HIE. A literature search in PubMed and EMBASE for case-control studies was conducted and 17 studies were found suitable by a priori criteria. Statistical analysis used the Mantel-Haenszel model for dichotomous data. The pooled mean difference and 95% confidence intervals (CIs) were determined. We identified the best biomarkers, based on the estimation approach in evaluating the biological significance, out of hundreds in three categories: cell adhesion and proliferation, oxidants and antioxidants, and cell damage. The following subtotal-population comparisons were made: perinatal asphyxia versus no asphyxia, asphyxia with HIE versus asphyxia without HIE, asphyxia with HIE versus no asphyxia, and term versus preterm HIE newborn with asphyxia. Biological significance of the biomarkers was determined by using a modification of the estimation approach, by ranking the biomarkers according to the difference in the bounds of the CIs. The most promising CSF biomarkers for prognostication especially for the severest HIE include creatine kinase, xanthine oxidase, vascular endothelial growth factor, neuron-specific enolase, superoxide dismutase, and malondialdehyde. Future studies are recommended using such a combined test to prognosticate the most severely affected patients.

Bone marrow mesenchymal stem cells-derived exosomal microRNA-124-3p attenuates hypoxic-ischemic brain damage through depressing tumor necrosis factor receptor associated factor 6 in newborn rats

Mesenchymal stem cells (MSCs)-derived exosomes (Exo) are beneficial in the use of brain damages. Restrictively, the mechanism of Exo expressing miR-124-3p in hypoxic-ischemic brain damage (HIBD) is not completely comprehended. Thereupon, this work was put forward to reveal the action of bone marrow MSCs-derived Exo (BMSCs-Exo) expressing miR-124-3p in the illness. BMSCs were isolated and transfected with miR-124-3p agomir. Then, BMSCs-Exo were extracted and identified. The newborn HIBD rats were injected with miR-124-3p-modified BMSCs-Exo or tumor necrosis factor receptor associated factor 6 (TRAF6)-related vectors. Next, neurological functions, neuron pathological and structural damages, oxidative stress and neuronal apoptosis were observed. miR-124-3p and TRAF6 expression was tested, along with their targeting relationship. miR-124-3p was down-regulated, and TRAF6 was up-regulated in newborn HIBD rats. miR-124-3p targeted TRAF6. BMSCs-Exo improved neurological functions, alleviated neuron pathological and structural damages, suppressed oxidative stress and reduced neuronal apoptosis in newborn HIBD rats, whereas BMSCs-Exo-mediated effects were enhanced by restoring miR-124-3p. Silencing TRAF6 attenuated HIBD in newborn rats, but overexpression of TRAF6 reversed the protective role of miR-124-3p-overexpressing BMSCs-Exo. This work makes it comprehensive that up-regulated exosomal miR-124-3p ameliorates HIBD in newborn rats by targeting TRAF6, which replenishes the potential agents for curing HIBD.

Maternal N-Acetyl-Cysteine Prevents Neonatal Hypoxia-Induced Brain Injury in a Rat Model

Perinatal hypoxia is a major cause of infant brain damage, lifelong neurological disability, and infant mortality. N-Acetyl-Cysteine (NAC) is a powerful antioxidant that acts directly as a scavenger of free radicals. We hypothesized that maternal-antenatal and offspring-postnatal NAC can protect offspring brains from hypoxic brain damage.Sixty six newborn rats were randomized into four study groups. Group 1: Control (CON) received no hypoxic intervention. Group 2: Hypoxia (HYP)-received hypoxia protocol. Group 3: Hypoxia-NAC (HYP-NAC). received hypoxia protocol and treated with NAC following each hypoxia episode. Group 4: NAC Hypoxia (NAC-HYP) treated with NAC during pregnancy, pups subject to hypoxia protocol. Each group was evaluated for: neurological function (Righting reflex), serum proinflammatory IL-6 protein levels (ELISA), brain protein levels: NF-κB p65, neuronal nitric oxide synthase (nNOS), TNF-α, and IL-6 (Western blot) and neuronal apoptosis (histology evaluation with TUNEL stain). Hypoxia significantly increased pups brain protein levels compared to controls. NAC administration to dams or offspring demonstrated lower brain NF-κB p65, nNOS, TNF-α and IL-6 protein levels compared to hypoxia alone. Hypoxia significantly increased brain apoptosis as evidenced by higher grade of brain TUNEL reaction. NAC administration to dams or offspring significantly reduce this effect. Hypoxia induced acute sensorimotor dysfunction. NAC treatment to dams significantly attenuated hypoxia-induced acute sensorimotor dysfunction. Prophylactic NAC treatment of dams during pregnancy confers long-term protection to offspring with hypoxia associated brain injury, measured by several pathways of injury and correlated markers with pathology and behavior. This implies we may consider prophylactic NAC treatment for patients at risk for hypoxia during labor.

Serial blood cytokine and chemokine mRNA and microRNA over 48 h are insult specific in a piglet model of inflammation-sensitized hypoxia-ischaemia

BACKGROUND

Exposure to inflammation exacerbates injury in neonatal encephalopathy (NE). We hypothesized that brain biomarker mRNA, cytokine mRNA and microRNA differentiate inflammation (E. coli LPS), hypoxia (Hypoxia), and inflammation-sensitized hypoxia (LPS+Hypoxia) in an NE piglet model.

METHODS

Sixteen piglets were randomized: (i) LPS 2 μg/kg bolus; 1 μg/kg infusion (LPS; n = 5), (ii) Saline with hypoxia (Hypoxia; n = 6), (iii) LPS commencing 4 h pre-hypoxia (LPS+Hypoxia; n = 5). Total RNA was acquired at baseline, 4 h after LPS and 1, 3, 6, 12, 24, 48 h post-insult (animals euthanized at 48 h). Quantitative PCR was performed for cytokines (IL1A, IL6, CXCL8, IL10, TNFA) and brain biomarkers (ENO2, UCHL1, S100B, GFAP, CRP, BDNF, MAPT). MicroRNA was detected using GeneChip (Affymetrix) microarrays. Fold changes from baseline were compared between groups and correlated with cell death (TUNEL) at 48 h.

RESULTS

Within 6 h post-insult, we observed increased IL1A, CXCL8, CCL2 and ENO2 mRNA in LPS+Hypoxia and LPS compared to Hypoxia. IL10 mRNA differentiated all groups. Four microRNAs differentiated LPS+Hypoxia and Hypoxia: hsa-miR-23a, 27a, 31-5p, 193-5p. Cell death correlated with TNFA (R = 0.69; p < 0.01) at 1-3 h and ENO2 (R = -0.69; p = 0.01) at 48 h.

CONCLUSIONS

mRNA and miRNA differentiated hypoxia from inflammation-sensitized hypoxia within 6 h in a piglet model. This information may inform human studies to enable triage for tailored neuroprotection in NE.

IMPACT

Early stratification of infants with neonatal encephalopathy is key to providing tailored neuroprotection. IL1A, CXCL8, IL10, CCL2 and NSE mRNA are promising biomarkers of inflammation-sensitized hypoxia. IL10 mRNA levels differentiated all three pathological states; fold changes from baseline was the highest in LPS+Hypoxia animals, followed by LPS and Hypoxia at 6 h. miR-23, -27, -31-5p and -193-5p were significantly upregulated within 6 h of a hypoxia insult. Functional analysis highlighted the diverse roles of miRNA in cellular processes.

Circular RNA cZNF292 silence alleviates OGD/R-induced injury through up-regulation of miR-22 in rat neural stem cells (NSCs)

Background: Hypoxic-ischaemic encephalopathy (HIE) is a prevailing severe brain damage disease in newborns, and caused by perinatal asphyxia cerebral ischaemia and reperfusion. Here, we investigated the role of cZNF292 in oxygen-glucose deprivation/reperfusion (OGD/R)-induced neural stem cells (NSCs) injury, and explored the underlying molecular mechanism.Methods: Before NSCs were subjected to OGD/R treatment, NSCs were transfected with or without overexpressing cZNF292, si-cZNF292 or miR-22 inhibitor. Viability, apoptosis and potential molecular mechanism were examined. Cell viability and apoptotic rate were evaluated utilizing cell counting kit-8 (CCK-8) and flow cytometry. The cZNF292 and miR-22 expression was determined utilizing quantitative reverse transcription-PCR (qRT-PCR). Moreover, apoptosis and Wnt/β-catenin and PKC/ERK pathways-associated proteins were quantified applying western blot.Results: OGD/R repressed viability and promoted apoptosis of NSCs. Also, cZNF292 expression was promoted by OGD/R treatment. Moreover, cZNF292 overexpression further caused OGD/R-stimulated damage. Inversely, silencing cZNF292 alleviated OGD/R-stimulated damage in NSCs. In addition, miR-22 expression was negatively regulated by cZNF292. It was confirmed that silencing cZNF292 attenuated OGD/R-induced NSCs injury and promoted the activation of Wnt/β-catenin and PKC/ERK pathways via the up-regulation of miR-22.Conclusions: The cZNF292 silence alleviated OGD/R-induced injury through the up-regulation of miR-22 in NSCs, and which furnished the theoretical basis for further research on HIE progression.

Investigation and comparison of the protective activities of three functional proteins-lactoferrin, α-lactalbumin, and β-lactoglobulin-in cerebral ischemia reperfusion injury

The objective of this study was to evaluate the protection conferred by lactoferrin, α-lactalbumin, and β-lactoglobulin in cerebral ischemia reperfusion (I/R) injury. Rat pheochromocytoma (PC12) cells were used to construct an oxygen and glucose deprivation model in vitro, and ICR mice underwent carotid artery "ligation-relaxation" to construct a cerebral I/R injury model in vivo. The levels of toll-like receptor 4 (TLR4) and downstream factors including nuclear factor-κB, tumor necrosis factor-α, and IL-1β were measured. Metabonomics detection and data mining were conducted to identify the specific metabolic sponsor of the 3 proteins. The results showed that lactoferrin, α-lactalbumin, and β-lactoglobulin protected neurons from cerebral I/R injury by increasing the level of bopindolol and subsequently inhibiting the TLR4-related pathway to different degrees; β-lactoglobulin had the strongest activity of the 3 proteins. In summary, this study is the first to investigate and compare the protective effects of lactoferrin, α-lactalbumin, and β-lactoglobulin in a cerebral stroke model. The results implicate TLR4 as a novel target of the 3 bioactive proteins to prevent cerebral I/R injury.

G-CSF attenuates neuroinflammation and neuronal apoptosis via the mTOR/p70SK6 signaling pathway in neonatal Hypoxia-Ischemia rat model

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is an important cause of permanent damage to the central nervous system, associated with long-lasting neurological disabilities and neurodevelopmental impairment in neonates. Granulocyte-colony stimulating factor (G-CSF) has been shown to have neuroprotective activity in a variety of experimental brain injury models and G-CSF is a standard treatment in chemotherapeutic-induced neutropenia. The underlying mechanisms are still unclear. The mTOR (mammalian target of rapamycin) signaling pathway is a master regulator of cell growth and proliferation in the nervous system. However, the effects of G-CSF treatment on the mTOR signaling pathway have not been elucidated in neonates with hypoxic-ischemic (HI) brain injury. Our study investigated the neuroprotective effect of G-CSF on neonates with hypoxic-ischemic (HI) brain injury and the possible mechanism involving the mTOR/p70S6K pathway.

METHODS

Sprague-Dawley rat pups at postnatal day 7 (P7) were subjected to right unilateral carotid artery ligation followed by hypoxic (8% oxygen and balanced nitrogen) exposure for 2.5 h or sham surgery. Pups received normal saline, G-CSF, G-CSF combined with rapamycin or ethanol (vehicle for rapamycin) intraperitoneally. On postnatal day 9 (P9), TTC staining for infarct volume, and Nissl and TUNEL staining for neuronal cell injury were conducted. Activation of mTOR/p70S6K pathway, cleaved caspase-3 (CC3), Bax and Bcl-2 and cytokine expression levels were determined by western blotting.

RESULTS

The G-CSF treated group was associated with significantly reduced infarction volume and decreased TUNEL positive neuronal cells compared to the HI group treated with saline. The expression levels of TNF-α and IL-1ß were significantly decreased in the G-CSF treated group, while IL-10 expression level was increased. The relative immunoreactivity of p-mTOR and p-p70S6K was significantly reduced in the HI group compared to sham. The HI group treated with G-CSF showed significant upregulated protein expression for p-mTOR and p-p70S6K levels compared to the HI group treated with saline. Furthermore, G-CSF treatment increased Bcl-2 expression levels and decreased CC3 and Bax expression levels in the ipsilateral hemispheres of the HI brain. The effects induced by G-CSF were all reversed by rapamycin.

CONCLUSION

Treatment with G-CSF decreases inflammatory mediators and apoptotic factors, attenuating neuroinflammation and neuronal apoptosis via the mTOR/p70S6K signalling pathway, which represents a potential target for treating HI induced brain damage in neonatal HIE.

MicroRNAs in the Blood-Brain Barrier in Hypoxic-Ischemic Brain Injury

Hypoxic-ischemic (HI) brain injury is a leading cause of acute mortality and chronic disability in newborns. Current evidence shows that cerebral microvascular response and compromised blood-brain barrier (BBB) integrity occur rapidly and could primarily be responsible for the brain injury observed in many infants with HI brain injury. MicroRNAs (miRNAs) are a type of highly conserved non-coding RNAs (ncRNAs), which consist of 21-25 nucleotides in length and usually lead to suppression of target gene expression. Growing evidence has revealed that brainenriched miRNAs act as versatile regulators of BBB dysfunctions in various neurological disorders including neonatal HI brain injury. In the present review, we summarize the current findings regarding the role of miRNAs in BBB impairment after hypoxia/ischemia brain injury. Specifically, we focus on the recent progress of miRNAs in the pathologies of neonatal HI brain injury. These findings can not only deepen our understanding of the role of miRNAs in BBB impairment in HI brain injury, but also provide insight into the development of new therapeutic strategies for preservation of BBB integrity under pathological conditions.

Inflammatory biomarkers in children with cerebral palsy: A systematic review

BACKGROUND

An exacerbated systemic inflammatory response has been associated with the occurrence of central nervous system injuries that may determine, in long term, motor, sensorial and cognitive disabilities. Persistence of this exacerbated inflammatory response seems to be involved in the pathophysiology of cerebral palsy (CP).

METHODS

A systematic search was conducted in Bireme, Embase, PubMed and Scopus including studies that were published until August 2019. The key words used were "cerebral palsy", "brain injury", "inflammation", "oxidative stress", "cytokines", "chemokines", "neuropsychomotor development", "neurodevelopment outcomes" and "child". The quality of the eligible studies was determined according to the criteria suggested by the Newcastle-Ottawa Scale (NOS).

RESULTS

Fourteen eligible studies aimed to investigate the association between peripheral inflammatory molecules and neurodevelopment in infants. The studies differed regarding CP-related risk factors and its classification. Inflammatory proteins were measured in blood, plasma, serum, cerebrospinal fluid or urine. In ten studies, higher circulating levels of cytokines, including IL-1β, IL-6, TNF and CXCL8/IL-8, were associated with abnormal neurological findings.

CONCLUSION

The investigation of the potential association between inflammatory molecules and neurological development in children with CP requires further original studies in order to clarify the influence of prenatal and perinatal inflammation on neurological outcomes.

Aqueous extract of Dendrobium officinale confers neuroprotection against hypoxic-ischemic brain damage in neonatal rats

Accumulating evidences have proved the protective role of traditional Chinese medicine in improving neurological damage induced by cerebral hypoxia-ischemia. Herein, we hypothesized that Dendrobium officinale aqueous extract exerted neuroprotection against brain damage. Initially, a model of hypoxic-ischemic brain damage (HIBD) was induced in neonatal rats, which were subsequently intragastrically administered with different doses of Dendrobium officinale aqueous extract. Next, the antioxidant capacity was examined by enzyme-linked immunosorbent assay. 2,3,5-Triphenyltetrazolium chloride and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining assays were adopted to determine neuronal apoptosis in brain tissues. Furthermore, neurotrophic factors and hypoxia-inducible factor-1α (HIF-1α) expression was identified by Western blot analysis. The neonatal rat models of HIBD presented impaired neurobehaviors and antioxidant capacity, increased neuronal apoptosis and expression of HIF-1α and histone deacetylase 1 (HDAC1), as well as diminished expression of neurotrophic factors and K⁺ -Cl^- -cotransporter 2 (KCC2). Notably, in response to different doses of Dendrobium officinale aqueous extract, the impairment on neurobehaviors and antioxidant capacity was alleviated, accompanied by reduced levels of nitric oxide synthase, nitric oxide, and malondialdehyde, and increased superoxide dismutase activity. Besides, the neuronal apoptosis was inhibited as reflected by down-regulated cleaved caspase-3 and Bax and up-regulated Bcl-2. Moreover, we also found accelerated expression of neurotrophic factors and KCC2 and diminished expression of HIF-1α and HDAC1. Altogether, this present study highlights that the aqueous extract of Dendrobium officinale can suppress the neuronal apoptosis and enhance the expression of neurotrophic factors to protect neonatal rats against HIBD.

Oxygen radical disease in the newborn, revisited: Oxidative stress and disease in the newborn period

Thirty years ago, there was an emerging appreciation for the significance of oxidative stress in newborn disease. This prompted a renewed interest in the impact of oxygen therapy for the newborn in the delivery room and beyond, especially in premature infants. Today, the complexity of oxidative stress both in normal regulation and pathology is better understood, especially as it relates to neonatal mitochondrial oxidative stress responses to hyperoxia. Mitochondria are recipients of oxidative damage and have a propensity for oxidative self-injury that has been implicated in the pathogenesis of neonatal lung diseases. Similarly, both intrauterine growth restriction (IUGR) and macrosomia are associated with mitochondrial dysfunction and oxidative stress. Additionally, reoxygenation with 100% O₂ in a hypoxic-ischemic newborn lamb model increased the production of pro-inflammatory cytokines in the brain. Moreover, the interplay between inflammation and oxidative stress in the newborn is better understood because of animal studies. Transcriptomic analyses have found a number of genes to be differentially expressed in murine models of bronchopulmonary dysplasia (BPD). Epigenetic changes have also been detected both in animal models of BPD and premature infants exposed to oxygen. Antioxidant therapy to prevent newborn disease has not been very successful; however, new therapeutic principles, like melatonin, are under investigation.

Seizures Are Associated with Blood-Brain Barrier Disruption in a Piglet Model of Neonatal Hypoxic-Ischaemic Encephalopathy

Seizures in the neonatal period are most often symptomatic of central nervous system (CNS) dysfunction and the most common cause is hypoxic-ischaemic encephalopathy (HIE). Seizures are associated with poor long-term outcomes and increased neuropathology. Blood-brain barrier (BBB) disruption and inflammation may contribute to seizures and increased neuropathology but are incompletely understood in neonatal HIE. The aim of this study was to investigate the impact of seizures on BBB integrity in a preclinical model of neonatal hypoxic-ischaemic (HI) injury. Piglets (age: <24 h) were subjected to a 30-min HI insult followed by recovery to 72 h post-insult. Amplitude-integrated electroencephalography (aEEG) was performed and seizure burden and background aEEG pattern were analysed. BBB disruption was evaluated in the parietal cortex and hippocampus by means of immunohistochemistry and Western blot. mRNA and protein expression of tight-junction proteins (zonula-occludens 1 [ZO1], occludin [OCLN], and claudin-5 [CLDN5]) was assessed using quantitative polymerase chain reaction (qPCR) and Western blot. In addition, mRNA from genes associated with BBB disruption vascular endothelial growth factor (VEGF) and matrix metalloproteinase 2 (MMP2) as well as inflammatory cytokines and chemokines was assessed with qPCR. Piglets that developed seizures following HI (HI-Sz) had significantly greater injury, as demonstrated by poorer aEEG background pattern scores, lower neurobehavioural scores, and greater histopathology. HI-Sz animals had severe IgG extravasation into brain tissue and uptake into neurons as well as significantly greater levels of IgG in both brain regions as assessed by Western blot. IgG protein in both brain regions was significantly associated with seizure burden, aEEG pattern scores, and neurobehavioural scores. There was no difference in mRNA expression of the tight junctions, however a significant loss of ZO1 and OCLN protein was observed in the parietal cortex. The inflammatory genes TGFβ, IL1β, IL8, IL6, and TNFα were significantly upregulated in HI-Sz animals. MMP2 was significantly increased in animals with seizures compared with animals without seizures. Increasing our understanding of neuropathology associated with seizure is vital because of the association between seizure and poor outcomes. Investigating the BBB is a major untapped area of research and a potential avenue for novel treatments.

Effects of propofol combined with remifentanil anesthesia on the NO, endothelin and inflammatory cytokines in the plasma of patients with liver cirrhosis during the perioperative period

The effects of propofol combined with remifentanil on the nitric oxide (NO), endothelin (ET-1) and inflammatory cytokines in the plasma of patients with liver cirrhosis were investigated. A retrospective analysis of 68 patients with liver cirrhosis who underwent hepatectomy in the Hunan Provincial People's Hospital from March 2016 to July 2018 was made. According to different anesthesia methods, 30 patients anesthetized with propofol were enrolled into Group A. The other 38 patients anesthetized with propofol combined with remifentanil were enrolled into Group B, and the operation time, amount of bleeding during operation and postoperative awake time of the two groups were recorded. At three separate time-points T₁ (30 min before the anesthesia), T₂ (after the portal triad clamping), T₃ (3 days after the operation), aspartate transaminase (AST) and alanine transaminase (ALT) levels in the plasma were measured by rate method, and the levels of NO, ET-1, interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in plasma were detected by enzyme-linked immunosorbent assay (ELISA). The plasma NO levels at the T₂ time-point were significantly lower than those at the T₁ and T₃ time-points (P<0.05); at the T₂ time-point, the concentrations of AST, ALT, ET-1, IL-6 and TNF-α in the plasma in Group A were significantly higher than those of Group B (P<0.05), while the levels of plasma NO in Group A were the opposite (P<0.05). The anesthesia of propofol combined with remifentanil could contribute to the balance of NO/ET-1 and the inhibition of inflammatory factors during the hepatectomy operation in patients with liver cirrhosis, and help to protect the liver function of patients, reducing the incidence of liver ischemia-reperfusion injury in patients.

microRNA-128 enhances neuroprotective effects of dexmedetomidine on neonatal mice with hypoxic-ischemic brain damage by targeting WNT1

OBJECTIVE

Hypoxic-ischemic brain damage (HIBD) is a major cause of acute mortality and chronic neurological morbidity in infants and children. Dexmedetomidine (DEX) is an effective choice in HIBD treatment. Recent findings have revealed that microRNA-128 (miR-128) is implicated in cerebral ischemia reperfusion. Hence, this study aimed to investigate the role of miR-128 in HIBD.

METHODS

HIBD models of neonatal mice were established. HIBD mice were treated with DEX, and injected with agomir (ago)-miR-128 or antagomir (anti)-miR-128 into the lateral ventricles to explore the influence of miR-128 on the neuroprotective effects of DEX on HIBD. Subsequently, the mice body weight, left/right (L/R) brain weight ratio, left-brain water content as well as learning and memory abilities were measured. Furthermore, the pathological changes of brain tissues and apoptosis rate of nerve cells were determined. The potential relationship between miR-128 and WNT1 was analyzed.

RESULTS

Over-expression of miR-128 caused an increase in mouse body weight, L/R brain weight ratio, and learning and memory abilities, while led to a decline in left-brain water content, brain tissue injury and apoptosis rate of nerve cells in DEX-treated HIBD mice. WNT1 was targeted and negatively regulated by miR-128. Silencing of WNT1 exerted the same effect as miR-128 on enhancing the neuroprotective effect of DEX on HIBD mice.

CONCLUSION

Collectively, miR-128 enhanced neuroprotective effect of DEX on HIBD neonatal mice by inhibiting WNT1.

MicroRNA-210 Downregulates ISCU and Induces Mitochondrial Dysfunction and Neuronal Death in Neonatal Hypoxic-Ischemic Brain Injury

Neonatal hypoxic-ischemic (HI) brain injury causes significant mortality and long-term neurologic sequelae. We previously demonstrated that HI significantly increased microRNA-210 (miR-210) in the neonatal rat brain and inhibition of brain endogenous miR-210 was neuroprotective in HI brain injury. However, the molecular mechanisms underpinning this neuroprotection remain unclear. Using both in vivo and in vitro models, herein we uncover a novel mechanism mediating oxidative brain injury after neonatal HI, in which miR-210 induces mitochondrial dysfunction via downregulation of iron-sulfur cluster assembly protein (ISCU). Inhibition of miR-210 significantly ameliorates mitochondrial dysfunction, oxidative stress, and neuronal loss in the neonatal brain subjected to HI, as well as in primary cortical neurons exposed to oxygen-glucose deprivation (OGD). These effects are mediated through ISCU, in that miR-210 mimic decreases ISCU abundance in the brains of rat pups and primary cortical neurons, and inhibition of miR-210 protects ISCU against HI in vivo or OGD in vitro. Deletion of miR-210 binding sequences at the 3'UTR of ISCU transcript ablates miR-210-induced downregulation of ISCU protein abundance in PC12 cells. In primary cortical neurons, miR-210 mimic or silencing ISCU results in mitochondrial dysfunction, reactive oxygen species production, and activation of caspase-dependent death pathways. Of importance, knockdown of ISCU increases HI-induced injury in the neonatal rat brain and counteracts the neuroprotection of miR-210 inhibition. Therefore, miR-210 by downregulating ISCU and inducing mitochondrial dysfunction in neurons is a potent contributor of oxidative brain injury after neonatal HI.

Geniposide protects PC-12 cells against oxygen and glucose deprivation-induced injury by up-regulation of long-noncoding RNA H19

AIMS

Hypoxic-ischemic encephalopathy (HIE) is a common brain injury disease in neonates, which can lead to neonatal disability and death. Geniposide (GEN) is a main ingredient of Gardenia jasminoides, whose anti-tumor, anti-inflammatory and anti-apoptotic effects have been reported in various diseases. However, the effect of GEN on HIE remains uninvestigated. This study aimed to clarify the protective effect of GEN on PC-12 cells against oxygen and glucose deprivation (OGD)-induced injury.

MAIN METHODS

PC-12 cells were subjected to OGD treatment, cell viability, cell cycle-associated factors, apoptosis and apoptosis-associated factors were then determined. The different concentrations of GEN were used to stimulate PC-12 cells, and the effects of GEN on cell proliferation and apoptosis in OGD-treatment cells were assessed. Subsequently, relative expression level of H19 was analyzed in PC-12 cells after treatment with GEN. After this, si-H19 was transfected into PC-12 cells to explore the regulatory effect of H19 on PC-12 cells after treatment with GEN and OGD. Besides, PI3K/AKT and Wnt/β-catenin pathways were examined by western blot assay.

KEY FINDINGS

OGD significantly inhibited cell viability, decreased CyclinD1, CDK4 and CDK6 expression, induced apoptosis and up-regulated Cleaved-Caspase-9/-7/-3 expression in PC-12 cells. GEN treatment obviously alleviated OGD-induced cell injury. Additionally, H19 expression was up-regulated by GEN, and H19 knockdown reversed the protective effect of GEN on PC-12 cells against OGD-induced injury. Finally, GEN activated PI3K/AKT and Wnt/β-catenin pathways by regulating H19 in OGD-insulted PC-12 cells.

SIGNIFICANCE

The findings suggested that GEN protected PC-12 cells against OGD-induced injury by up-regulation of H19.

Early Prediction of Hypoxic-Ischemic Brain Injury by a New Panel of Biomarkers in a Population of Term Newborns

This research paper is aimed at evaluating the predictive role of a default panel of oxidative stress (OS) biomarkers for the early identification of infants at high risk of HIE and their validation through the correlation with MRI findings. A multicenter prospective observational study was performed between March 2012 and April 2015 in two European tertiary NICUs. Eighty-four term infants at risk for HIE (pH < 7, BE < −13 mmol/L, and 5′ Apgar < 5) were enrolled. Three were excluded for chromosomal abnormalities and one due to lack of blood samples. The final population was divided according to the severity of perinatal hypoxia into 2 groups: mild/moderate HIE and severe HIE. Advanced oxidation protein products (AOPP), non-protein-bound iron (NPBI), and F2-isoprostanes (F2-IsoPs) were measured in blood samples at P1 (4–6 hours), P2 (24–72 hours), and P3 (5 days), in both groups. MRIs were scored for the severity of brain injury, using a modified Barkovich score. The mean GA was 39.8 weeks (SD 1.4) and the mean birth weight 3538 grams (SD 660); 37 were females and 43 males. Significantly lower 5′ Apgar score, pH, and BE and higher Thompson score were found in group II compared to group I at birth. Group II showed significantly higher AOPP and NPBI levels than group I (mean (SD) AOPP: 15.7 (15.5) versus 34.1 (39.2), p = 0.033; NPBI 1.1 (2.5) versus 3.9 (4.4), p = 0.013) soon after birth (P1). No differences were observed in OS biomarker levels between the two groups at P2 and P3. A regression model, including adjustment for hypothermia treatment, gender, and time after birth, showed that AOPP levels and male gender were both risk factors for higher brain damage scores (AOPP: OR 3.6, 95% CI (1.1–12.2) and gender: OR 5.6, 95% CI (1.2–25.7), resp.). Newborns with severe asphyxia showed higher OS than those with mild asphyxia at birth. AOPP are significantly associated with the severity of brain injury assessed by MRI, especially in males.

C-type natriuretic peptide functions as an innate neuroprotectant in neonatal hypoxic-ischemic brain injury in mouse via natriuretic peptide receptor 2

Neonatal hypoxia-ischemia (HI) is the most common cause of brain injury in neonates, which leads to high neonatal mortality and severe neurological morbidity in later life (Vannucci, 2000; Volpe, 2001). Yet the molecular mechanisms of neuronal death and brain damage induced by neonatal HI remain largely elusive. Herein, using both in vivo and in vitro models, we determine an endogenous neuroprotectant role of c-type natriuretic peptide (CNP) in preserving neuronal survival after HI brain injury in mouse pups. Postnatal day 7 (P7) mouse pups with CNP deficiency (Nppc^lbab/lbab) exhibit increased brain infarct size and worsened long-term locomotor function after neonatal HI compared with wildtype control (Nppc^+/+). In isolated primary cortical neurons, recombinant CNP dose-dependently protects primary neurons from oxygen-glucose deprivation (OGD) insult. This neuroprotective effect appears to be mediated through its cognate natriuretic peptide receptor 2 (NPR2), in that antagonization of NPR2, but not NPR3, exacerbates neuronal death and counteracts the protective effect of CNP on primary neurons exposed to OGD insult. Immunoblot and confocal microscopy demonstrate the abundant expression of NPR2 in neurons of the neonatal brain and in isolated primary cortical neurons as well. Moreover, similar to CNP deficiency, administration of NPR2 antagonist P19 via intracerebroventricular injection prior to HI results in exacerbated neuronal death and brain injury after HI. Altogether, the present study indicates that CNP and its cognate receptor NPR2 mainly expressed in neurons represent an innate neuroprotective mechanism in neonatal HI brain injury.

Role of LncRNA MALAT-1 in hypoxia-induced PC12 cell injury via regulating p38MAPK signaling pathway

OBJECTIVE

To investigate the role of LncRNA MALAT-1 in hypoxia-induced cell injury.

METHODS

Pheochromocytoma-12 (PC12) cells were divided into seven groups: Control group, Hypoxia group (Cells treated with CoCl₂), MALAT-1 group (Hypoxic cells treated with MALAT-1), NC group (Hypoxic cells treated with empty plasmid), MALAT-1 siRNA group (Hypoxic cells treated with siRNA MALAT-1), SB203580 group (Hypoxic cells treated with p38MAPK inhibitor), and MALAT-1 + SB20358 group. The content of reactive oxygen species (ROS), malondialdehyde (MDA), super oxide dismutase (SOD) and lactate dehydrogenase (LDH) was determined. Cell viability was detected by MTT assay. Apoptotic cells were observed by Hoechst 33258 and TUNEL staining assay. Mitochondrial membrane potential (MMP) was measured using JC1 vital dye.

RESULTS

The decreased cell viability and increased expressions of MALAT-1 and p-p38 were observed in hypoxic PC12 cells time-dependently (P < 0.05). Besides, hypoxic PC12 cells had an elevation in p-p38, ROS, MDA and LDH with the increased apoptotic cells, but a reduction in SOD and MMP, and these similar changes were more obvious in those hypoxic cells treated with MALAT-1 when compared with Controls (all P < 0.05). However, the hypoxic PC12 cells treated with SB203580 and MALAT-1 siRNA led to opposite results compared with MALAT-1 group (all P < 0.05). Importantly, SB203580 could reverse the function of MALAT-1 in aggravating the hypoxia injury of PC12 cells.

CONCLUSION

MALAT-1 can promote the apoptosis and oxidative stress of PC12 cells by activating p38MAPK pathway, thus aggravating the damage of PC12 cells induced by chemical hypoxia.

Benefits of starting hypothermia treatment within 6 h vs. 6-12 h in newborns with moderate neonatal hypoxic-ischemic encephalopathy

BACKGROUND

It has been suggested that mild hypothermia treatment of hypoxia-ischemic encephalopathy (HIE) should start within 6 h after HIE, but many children are admitted to the hospital > 6 h, particularly in developing areas. We aimed to determine whether hypothermia treatment could remain effective within 12 h after birth.

METHODS

According to their admission, 152 newborns were enrolled in the < 6 h and 6-12 h after HIE groups. All newborns received conventional treatment combined with mild head hypothermia therapy, according to our routine clinical practice. Some newborns only received conventional treatment (lacking informed consent). All newborns received amplitude-integrated electroencephalography (aEEG) monitoring for 4 h and neuron-specific enolase (NSE) measurement before and after 3 days of therapy.

RESULTS

Compared to the conventional treatment, hypothermia significantly improved the aEEG scores and NSE values in all newborns of the < 6-h group. In the 6-12-h group, the aEEG scores (F = 5.67, P < 0.05) and NSE values (F = 4.98, P < 0.05) were only improved in newborns with moderate HIE. Hypothermia treatment seems to have no effect in newborns with severe HIE after 6 h (P > 0.05). Hypothermia improved the rates of neonatal death and 18-month disability (all P < 0.01).

CONCLUSIONS

In newborns with moderate HIE, starting hypothermia therapy < 6 h and 6-12 h after HIE showed curative effects. In those with severe HIE, only starting hypothermia therapy within 6 h showed curative effects.

The impact of hypoxic-ischemic brain injury on stem cell mobilization, migration, adhesion, and proliferation

Neonatal hypoxic-ischemic encephalopathy continues to be a significant cause of death or neurodevelopmental delays despite standard use of therapeutic hypothermia. The use of stem cell transplantation has recently emerged as a promising supplemental therapy to further improve the outcomes of infants with hypoxic-ischemic encephalopathy. After the injury, the brain releases several chemical mediators, many of which communicate directly with stem cells to encourage mobilization, migration, cell adhesion and differentiation. This manuscript reviews the biomarkers that are released from the injured brain and their interactions with stem cells, providing insight regarding how their upregulation could improve stem cell therapy by maximizing cell delivery to the injured tissue.

Association Between Perinatal Hypoxic-Ischemic Conditions and Attention-Deficit/Hyperactivity Disorder: A Meta-Analysis

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a common neuropsychiatric disorder worldwide, but its etiology is still not fully understood. Previous studies have reported that perinatal hypoxic-ischemic conditions may be a potential cause of ADHD.

METHODS

An online search of potential English studies published before September 2015 was conducted using the PsycINFO, EMBASE, Web of Science, and PubMed databases. The combined odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with random-effects models.

RESULTS

Ten studies were included, with 45 821 cases and 9 207 363 controls. The metaresults found that the following were associated with ADHD: preeclampsia (OR 1.31; 95% CI 1.26-1.37), an Apgar score <7 at 5 minutes (OR 1.31; 95% CI 1.12-1.54), breech/transverse presentations (OR 1.14; 95% CI 1.06-1.23), and a prolapsed/nuchal cord (OR 1.10; 95% CI 1.06-1.15).

CONCLUSION

Our results support that perinatal hypoxia-ischemia may contribute to ADHD. However, more clinical studies are warranted.

Diffusion Tensor Imaging of White Matter Injury Caused by Prematurity-Induced Hypoxic-Ischemic Brain Damage

Background

This investigation aimed to evaluate changes in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of white matter injury (WMI) in preterm neonates with hypoxic-ischemic encephalopathy (HIE) using diffusion tension imaging (DTI).

Material/Methods

Thirty-eight neonates less than 37 weeks of gestation with leukoencephalopathy (as observation group) and 38 full-term infants with no leukoencephalopathy (as control group) were selected from the Neonatal Care Center in Taian Central Hospital from January 2012 to December 2013. A DTI scan was obtained within 1 week after birth.

Results

In the observation group, on both sides the ADC values in regions of interest (ROI) of white matter, lesions were greater and FA values were lower than in the control group. ADC and FA values in genu and splenum of corpus callosum were statistically different between the mild and severe injury groups (p<0.05).

Conclusions

This study demonstrates that DTI provides sensitive detection and early diagnosis of WMI in brains of premature infants with HIE.

Biomarkers of multiorgan injury in neonatal encephalopathy

Neonatal encephalopathy (NE) is a major contributor to neurodevelopmental deficits including cerebral palsy in term and near-term infants. The long-term neurodevelopmental outcome is difficult to predict with certainty in first few days of life. Multiorgan involvement is common but not part of the diagnostic criteria for NE. The most frequently involved organs are the heart, liver, kidneys and hematological system. Cerebral and organ involvement is associated with the release of organ specific biomarkers in cerebrospinal fluid, urine and blood. These biomarkers may have a role in the assessment of the severity of asphyxia and long-term outcome in neonates with NE.

Plasma Biomarkers of Oxidative Stress in Neonatal Brain Injury

Perinatal encephalopathy is a leading cause of lifelong disability. Increasing evidence indicates that the pathogenesis of perinatal brain damage is much more complex than originally thought, with multiple pathways involved. An important role of oxidative stress (OS) in the pathogenesis of brain injury is recognized for preterm and term infants. This article examines potential reliable and specific OS biomarkers that can be used in premature and term infants for the early detection and follow-up of the most common neonatal brain injuries, such as hypoxic-ischemic encephalopathy, intraventricular hemorrhage, and periventricular leukomalacia. The next step will be to explore the correlation between brain-specific OS biomarkers and functional brain outcomes.

Oxymatrine attenuated hypoxic-ischemic brain damage in neonatal rats via improving antioxidant enzyme activities and inhibiting cell death

Oxymatrine (OMT), an active constituent of Chinese herb Sophora flavescens Ait, has been proved to possess anti-tumor, anti-oxidant, anti-inflammatory, and anti-apoptotic activities. Previous study has demonstrated that OMT had protective roles on multiple in vitro and in vivo brain injury models including regulation of apoptosis-related proteins caspase-3, Bax and Bcl-2. In this study, we investigated whether this protective effect could apply to neonatal hypoxic-ischemic brain damage. Seven-day-old Sprague-Dawley rats were treated with the left carotid artery ligation followed by exposure to 8% oxygen (balanced with nitrogen) for 2.5 h at 37 °C. In sham group rats, neither ligation nor hypoxia was performed. After two successive days intraperitoneal injection with OMT (30, 60 and 120 mg/kg), Nimodipine (1 mg/kg), and saline, brain infarct volume was estimated, histomorphology changes were performed by hematoxylin-eosin (HE) staining as well as electron microscopy. In addition, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC), as well as production of malondialdehyde (MDA) were assayed in ipsilateral hemisphere homogenates to evaluate the redox status after hypoxic-ischemic. Expression of apoptosis-related proteins Caspase-3, Bax and Bcl-2 in brain were analyzed by western-blot analysis and immunofluorescence. Administration of OMT significantly decreased brain infarct volume and the percentage of injured cells, and ameliorated histopathology and morphological injury as well. Furthermore, OMT obviously increased the activities of SOD, GSH-Px, CAT and T-AOC, and decreased MDA content. Western-blot analysis showed a marked decrease in Caspase-3 expression and increase in the ratio of Bcl-2/Bax after OMT (120 mg/kg) post-treatment as compared with hypoxic-ischemic group. These results suggest that OMT exerts a neuroprotective effect against hypoxic-ischemic brain damage in neonatal rats, which is likely to be mediated through increasing anti-oxidant enzyme activities and inhibiting cell death.

Angiogenesis dysregulation in term asphyxiated newborns treated with hypothermia

BACKGROUND

Neonatal encephalopathy following birth asphyxia is a major predictor of long-term neurological impairment. Therapeutic hypothermia is currently the standard of care to prevent brain injury in asphyxiated newborns but is not protective in all cases. More robust and versatile treatment options are needed. Angiogenesis is a demonstrated therapeutic target in adult stroke. However, no systematic study examines the expression of angiogenesis-related markers following birth asphyxia in human newborns.

OBJECTIVE

This study aimed to evaluate the expression of angiogenesis-related protein markers in asphyxiated newborns developing and not developing brain injury compared to healthy control newborns.

DESIGN/METHODS

Twelve asphyxiated newborns treated with hypothermia were prospectively enrolled; six developed eventual brain injury and six did not. Four healthy control newborns were also included. We used Rules-Based Medicine multi-analyte profiling and protein array technologies to study the plasma concentration of 49 angiogenesis-related proteins. Mean protein concentrations were compared between each group of newborns.

RESULTS

Compared to healthy newborns, asphyxiated newborns not developing brain injury showed up-regulation of pro-angiogenic proteins, including fatty acid binding protein-4, glucose-6-phosphate isomerase, neuropilin-1, and receptor tyrosine-protein kinase erbB-3; this up-regulation was not evident in asphyxiated newborns eventually developing brain injury. Also, asphyxiated newborns developing brain injury showed a decreased expression of anti-angiogenic proteins, including insulin-growth factor binding proteins -1, -4, and -6, compared to healthy newborns.

CONCLUSIONS

These findings suggest that angiogenesis pathways are dysregulated following birth asphyxia and are putatively involved in brain injury pathology and recovery.

Current proceedings of cerebral palsy

Cerebral palsy (CP) is a complicated disease with varying causes and outcomes. It has created significant burden to both affected families and societies, not to mention the quality of life of the patients themselves. There is no cure for the disease; therefore, development of effective therapeutic strategies is in great demand. Recent advances in regenerative medicine suggest that the transplantation of stem cells, including embryonic stem cells, neural stem cells, bone marrow mesenchymal stem cells, induced pluripotent stem cells, umbilical cord blood cells, and human embryonic germ cells, focusing on the root of the problem, may provide the possibility of developing a complete cure in treating CP. However, safety is the first factor to be considered because some stem cells may cause tumorigenesis. Additionally, more preclinical and clinical studies are needed to determine the type of cells, route of delivery, cell dose, timing of transplantation, and combinatorial strategies to achieve an optimal outcome.

Inflammatory response and oxidative stress in developing rat brain and its consequences on motor behavior following maternal administration of LPS and perinatal anoxia

Cerebral palsy (CP) is a disorder of locomotion, posture and movement that can be caused by prenatal, perinatal or postnatal insults during brain development. An increased incidence of CP has been correlated to perinatal asphyxia and maternal infections during gestation. The effects of maternal exposure to low doses of bacterial endotoxin (lipopolysaccharide, LPS) associated or not with perinatal anoxia (PA) in oxidative and inflammatory parameters were examined in cerebral cortices of newborns pups. Concentrations of TNF-α, IL-1, IL-4, SOD, CAT and DCF were measured by the ELISA method. Other newborn rats were assessed for neonatal developmental milestones from day 1 to 21. Motor behavior was also tested at P29 using open-field and Rotarod. PA alone only increased IL-1 expression in cerebral cortex with no changes in oxidative measures. PA also induced a slight impact on development and motor performance. LPS alone was not able to delay motor development but resulted in changes in motor activity and coordination with increased levels of IL-1 and TNF-α expression associated with a high production of free radicals and elevated SOD activity. When LPS and PA were combined, changes on inflammatory and oxidative stress parameters were greater. In addition, greater motor development and coordination impairments were observed. Prenatal exposure of pups to LPS appeared to sensitize the developing brain to effects of a subsequent anoxia insult resulting in an increased expression of pro-inflammatory cytokines and increased free radical levels in the cerebral cortex. These outcomes suggest that oxidative and inflammatory parameters in the cerebral cortex are implicated in motor deficits following maternal infection and perinatal anoxia by acting in a synergistic manner during a critical period of development of the nervous system.

Brain susceptibility to oxidative stress in the perinatal period

Oxidative stress (OS) occurs at birth in all newborns as a consequence of the hyperoxic challenge due to the transition from the hypoxic intrauterine environment to extrauterine life. Free radical (FRs) sources such as inflammation, hyperoxia, hypoxia, ischaemia-reperfusion, neutrophil and macrophage activation, glutamate and free iron release, all increases the OS during the perinatal period. Newborns, and particularly preterm infants, have reduced antioxidant defences and are not able to counteract the harmful effects of FRs. Energy metabolism is central to life because cells cannot exist without an adequate supply of ATP. Due to its growth, the mammalian brain can be considered as a steady-state system in which ATP production matches ATP utilisation. The developing brain is particularly sensitive to any disturbances in energy generation, and even a short-term interruption can lead to long-lasting and irreversible damage. Whenever energy failure develops, brain damage can occur. Accumulating evidence indicates that OS is implicated in the pathogenesis of many neurological diseases, such as intraventricular haemorrhage, hypoxic-ischaemic encephalopathy and epilepsy.

Changes of amplitude integration electroencephalogram (aEEG) in different maturity preterm infant

BACKGROUND

With the improvement of perinatal care and neonatal intensive care technology in recent years, a preterm infant, especially with small gestational age and very low birth weight, survives more and more. At the same time, adverse neurodevelopmental prognosis caused by brain damage in preterm infant also increased significantly. Preterm infant brain injury has become the most important factor for early death and neurodevelopment of preterm infant.

METHODS

Amplitude integration electroencephalogram (aEEG) has an important clinical value in the assessment of brain development in the maturity of preterm infant. With the application of a neonatal brain function monitor, we value the aEEG graphic continuity, periodicity, narrowband lower margin amplitude, and bandwidth score and analyze wide- and narrowband on the lower bounds of voltage and bandwidth.

RESULTS

The graphics of preterm infant aEEG become mature with the growth of the gestational age (1). With the growth of corrected gestational age, the aEEG graphics of preterm infant has the following feature: lower bound voltage of narrowband rising and width narrowing of narrowband (2). Extrauterine life can speed up the maturation of aEEG graphics (3).

CONCLUSIONS

The aEEG technology is a noninvasive, operable, and simple analysis and suitable for application in the newborn intensive care unit.

VEGF expression and microvascular responses to severe transient hypoxia in the fetal sheep brain

BACKGROUND

Fetal hypoxia contributes significantly to the pathogenesis of permanent perinatal brain injury. We hypothesized that hypoxia-induced cerebral angiogenesis and microvascular changes would occur in fetal sheep subjected to a severe hypoxic insult produced by umbilical cord occlusion (UCO) for 10 min.

METHODS

At 124-126 d of gestation, singleton fetal sheep underwent surgery for implantation of catheters and placement of an inflatable cuff around the umbilical cord. A 10-min UCO or sham UCO (n = 5) was induced at 130 d gestation. The fetal brain was collected at 24 h (n = 5) or 48 h (n = 4) after UCO for immunohistochemical analysis of vascular endothelial growth factor (VEGF), Ki67, and serum albumin.

RESULTS

By 48 h after UCO, the percentage of blood vessels expressing VEGF had increased in the subventricular zone, periventricular and subcortical white matter, corpus callosum, and cortex. Alterations in vascular permeability (albumin extravasation) were observed only in the periventricular and subcortical white matter and the subventricular zone following UCO.

CONCLUSION

The upregulation of VEGF expression and increased leakage of plasma protein in the fetal sheep brain show that the microvasculature in white matter is sensitive to hypoxia in the near-term brain.

Vulnerability of the developing brain to hypoxic-ischemic damage: contribution of the cerebral vasculature to injury and repair?

As clinicians attempt to understand the underlying reasons for the vulnerability of different regions of the developing brain to injury, it is apparent that little is known as to how hypoxia-ischemia may affect the cerebrovasculature in the developing infant. Most of the research investigating the pathogenesis of perinatal brain injury following hypoxia-ischemia has focused on excitotoxicity, oxidative stress and an inflammatory response, with the response of the developing cerebrovasculature receiving less attention. This is surprising as the presentation of devastating and permanent injury such as germinal matrix-intraventricular haemorrhage (GM-IVH) and perinatal stroke are of vascular origin, and the origin of periventricular leukomalacia (PVL) may also arise from poor perfusion of the white matter. This highlights that cerebrovasculature injury following hypoxia could primarily be responsible for the injury seen in the brain of many infants diagnosed with hypoxic-ischemic encephalopathy (HIE). Interestingly the highly dynamic nature of the cerebral blood vessels in the fetus, and the fluctuations of cerebral blood flow and metabolic demand that occur following hypoxia suggest that the response of blood vessels could explain both regional protection and vulnerability in the developing brain. However, research into how blood vessels respond following hypoxia-ischemia have mostly been conducted in adult models of ischemia or stroke, further highlighting the need to investigate how the developing cerebrovasculature responds and the possible contribution to perinatal brain injury following hypoxia. This review discusses the current concepts on the pathogenesis of perinatal brain injury, the development of the fetal cerebrovasculature and the blood brain barrier (BBB), and key mediators involved with the response of cerebral blood vessels to hypoxia.

Effects of hypothermia on NSE and S-100 protein levels in CSF in neonates following hypoxic/ischaemic brain damage

AIM

The aim of the study was to evaluate the effects of hypothermia on neuron-specific enolase (NSE) and S-100 protein levels in cerebrospinal fluid (CSF) in neonates with hypoxic/ischaemic encephalopathy (HIE).

METHODS

Fifty-one enrolled neonates with HIE were divided into two groups: hypothermia (n = 23) and control (n = 28). NSE and S-100 protein were measured with immunoradiometric assays. Amino acid neurotransmitters were also measured by reversed-phase high-performance liquid chromatography. Neurodevelopmental assessments were performed at 3 and 12 months of age.

RESULTS

Neuron-specific enolase and S-100 levels were lower, and neurodevelopment outcome was better in the hypothermia group compared with the control group. Among the infants who received hypothermia, CSF NSE and S-100 were significantly higher in those who developed severe neurological impairment (mental development index or physical development index <70). There were no significant differences between the two groups in amino acid neurotransmitters.

CONCLUSION

These results indicated that hypothermia was associated with decreased CSF NSE and S-100 level and correlated with neurodevelopmental outcome in infants with HIE.