Tertiary mechanisms of brain damage: A new hope for treatment of cerebral palsy? Lancet Neurol. 2012;11:556-566. [PMID: 22608669 DOI: 10.1016/s1474-4422(12)70058-3]

Mesenchymal Stromal Cell therapy for Hypoxic Ischemic Encephalopathy: Future directions for combination therapy with hypothermia and/or melatonin

Hypoxic ischemic encephalopathy (HIE) remains a leading cause of neonatal mortality and lifelong disability across the world. While therapeutic hypothermia (HT) is beneficial, it is only partially protective and adjuvant treatments that further improve outcomes are urgently needed. In high-income countries where HT is standard care, novel treatments are tested in conjunction with HT. Mesenchymal stromal cells (MSC) represent a paradigm shift in brain protection, uniquely adapting to the host cellular microenvironment. MSC have low immunogenicity and potent paracrine effects stimulating the host tissue repair and regeneration and reducing inflammation and apoptosis. Preclinical studies in perinatal brain injury suggest that MSC are beneficial after hypoxia-ischemia (HI) and most preclinical studies of MSC with HT show protection. Preclinical and early phase clinical trials have shown that allogenic administration of MSC to neonates with perinatal stroke and HIE is safe and feasible but further safety and efficacy studies of HT with MSC in these populations are needed. Combination therapies that target all stages of the evolution of injury after HI (eg HT, melatonin and MSC) show promise for improving outcomes in HIE.

Neuroinflammatory markers at school age in preterm born children with neurodevelopmental impairments

Background

Immune system activation in the neonatal period is associated with white matter injury in preterm infants. In animal studies, neonatal priming of the immune system leads to chronic activation of i.e. microglia cells and altered neuroinflammatory responses potentially years after preterm birth. This may contribute further to brain injury and neurodevelopmental impairment. It is unknown to what extend this also occurs in human.

Aim

To identify neuro-inflammatory markers at school age that relate to motor, cognitive and behavioral impairments in preterm born children in a pilot case-control study.

Methods

We included n = 20 preterm born children (GA < 28 weeks) in this study, of which n = 10 with motor, cognitive and behavorial impairments and n = 10 preterm born controls next to n = 30 healthy adult controls. In the preterm children, at 8-9 years, 39 inflammatory markers were assessed by Luminex assay in blood serum samples. Firstly, the preterm concentrations of these markers were compared to n = 30 adult controls. Then a univariate analysis was performed to determine differences in values between preterm children with and without impairment at school age. Finally, a principal component analysis and hierarchical clustering was performed to identify protein profiles in preterm born children that relate to impairment at school age.

Results

Inflammatory proteins in preterm children at school age differed from values of adult controls. Within the group of preterm children, we found significantly higher levels of GM-CSF in preterms with impairment (p < 0.01) and a trend towards significance for Gal1 and TRAIL (p = 0.06 and p = 0.06 respectively) when compared to preterms without impairment. In addition, differences in clustering of proteins between preterm children was observed, however this variance was not explained by presence of neurodevelopmental impairments.

Conclusion

The inflammatory profile at school age in preterm children is different from that of adult controls. The immune modulating cytokines GM-CSF, Gal1 and TRAIL were higher in preterm children with impairment than control preterm children, suggesting that immune responses are altered in these children. No specific cluster of inflammatory markers could be identified. Results indicate that even at school age, neuroinflammatory pathways are activated in preterm born children with neurodevelopmental impairments.

Mechanisms and timing of brain injury among persons with cerebral palsy

This commentary is on the original article by Reid et al. on pages 892–901

Regulated cell death in hypoxic-ischaemic encephalopathy: recent development and mechanistic overview

Hypoxic-ischaemic encephalopathy (HIE) in termed infants remains a significant cause of morbidity and mortality worldwide despite the introduction of therapeutic hypothermia. Depending on the cell type, cellular context, metabolic predisposition and insult severity, cell death in the injured immature brain can be highly heterogenous. A continuum of cell death exists in the H/I-injured immature brain. Aside from apoptosis, emerging evidence supports the pathological activation of necroptosis, pyroptosis and ferroptosis as alternative regulated cell death (RCD) in HIE to trigger neuroinflammation and metabolic disturbances in addition to cell loss. Upregulation of autophagy and mitophagy in HIE represents an intrinsic neuroprotective strategy. Molecular crosstalk between RCD pathways implies one RCD mechanism may compensate for the loss of function of another. Moreover, mitochondrion was identified as the signalling "hub" where different RCD pathways converge. The highly-orchestrated nature of RCD makes them promising therapeutic targets. Better understanding of RCD mechanisms and crosstalk between RCD subtypes likely shed light on novel therapy development for HIE. The identification of a potential RCD converging node may open up the opportunity for simultaneous and synergistic inhibition of cell death in the immature brain.

Severe neurological impairment and immune function: altered neutrophils, monocytes, T lymphocytes, and inflammasome activation

BACKGROUND

Infections cause significant morbidity and mortality in children with Severe Neurological Impairment (SNI). Alterations in immune cell numbers and function in children with neurodisability have been reported. We aimed to characterise neutrophil, monocyte and lymphocyte proportions and activation, at baseline and in response to stimulation with lipopolysaccharide, in children with SNI compared to healthy controls.

METHODS

Whole blood samples of children with SNI and controls were incubated in the presence or absence of lipopolysaccharide (10 ng/ml). Monocyte and neutrophil function (Cluster of Differentiation (CD)11b, (TLR)-4 and CD66b expression) and lymphocytes were assessed by flow cytometry. Expression of genes involved in the inflammasome (NLR Family Pyrin Domain Containing(NLRP)-3, Apoptosis-Associated Speck-like protein (ASC) and Interleukin(IL)1β) were assessed by PCR.

RESULTS

Monocytes and CD8+ T cells were lower in children with SNI (n = 14). CD66b, was hyporesponsive and monocyte TLR4 was hyperresponsive to lipopolysaccharide in children with SNI compared to controls (n = 14). NLRP3 expression was higher at baseline and IL1β expression was not upregulated in response to lipopolysaccharide in children with SNI in contrast to controls.

CONCLUSION

We have found significant differences in immune regulation in children with SNI compared to controls which may provide a useful therapeutic target in the future.

IMPACT

Children with SNI have reduced monocyte and CD8+ T cells. Neutrophils and monocytes in children with SNI show altered markers of activation in response to lipopolysaccharide. Expression of NLRP3 at the RNA level was higher at baseline in children with SNI. This study adds to the existing literature that children with neurological impairment have altered inflammatory and immune cell responses. This may provide a useful therapeutic target to reduce infection-related morbidity and mortality, and tertiary neurological injury in the future.

Inflammatory, metabolic, and sex-dependent gene-regulatory dynamics of microglia and macrophages in neonatal hippocampus after hypoxia-ischemia

Neonatal hypoxia-ischemia (HI) is a major cause of perinatal death and long-term disabilities worldwide. Post-ischemic neuroinflammation plays a pivotal role in HI pathophysiology. In the present study, we investigated the temporal dynamics of microglia (CX3CR1GFP/+) and infiltrating macrophages (CCR2RFP/+) in the hippocampi of mice subjected to HI at postnatal day 9. Using inflammatory pathway and transcription factor (TF) analyses, we identified a distinct post-ischemic response in CCR2RFP/+ cells characterized by differential gene expression in sensome, homeostatic, matrisome, lipid metabolic, and inflammatory molecular signatures. Three days after injury, transcriptomic signatures of CX3CR1GFP/+ and CCR2RFP/+ cells isolated from hippocampi showed a partial convergence. Interestingly, microglia-specific genes in CX3CR1GFP/+ cells showed a sexual dimorphism, where expression returned to control levels in males but not in females during the experimental time frame. These results highlight the importance of further investigations on metabolic rewiring to pave the way for future interventions in asphyxiated neonates.

Neuroprotective therapies in the NICU in preterm infants: present and future (Neonatal Neurocritical Care Series)

The survival of preterm infants has steadily improved thanks to advances in perinatal and neonatal intensive clinical care. The focus is now on finding ways to improve morbidities, especially neurological outcomes. Although antenatal steroids and magnesium for preterm infants have become routine therapies, studies have mainly demonstrated short-term benefits for antenatal steroid therapy but limited evidence for impact on long-term neurodevelopmental outcomes. Further advances in neuroprotective and neurorestorative therapies, improved neuromonitoring modalities to optimize recruitment in trials, and improved biomarkers to assess the response to treatment are essential. Among the most promising agents, multipotential stem cells, immunomodulation, and anti-inflammatory therapies can improve neural outcomes in preclinical studies and are the subject of considerable ongoing research. In the meantime, bundles of care protecting and nurturing the brain in the neonatal intensive care unit and beyond should be widely implemented in an effort to limit injury and promote neuroplasticity. IMPACT: With improved survival of preterm infants due to improved antenatal and neonatal care, our focus must now be to improve long-term neurological and neurodevelopmental outcomes. This review details the multifactorial pathogenesis of preterm brain injury and neuroprotective strategies in use at present, including antenatal care, seizure management and non-pharmacological NICU care. We discuss treatment strategies that are being evaluated as potential interventions to improve the neurodevelopmental outcomes of infants born prematurely.

Key roles of glial cells in the encephalopathy of prematurity

Across the globe, approximately one in 10 babies are born preterm, that is, before 37 weeks of a typical 40 weeks of gestation. Up to 50% of preterm born infants develop brain injury, encephalopathy of prematurity (EoP), that substantially increases their risk for developing lifelong defects in motor skills and domains of learning, memory, emotional regulation, and cognition. We are still severely limited in our abilities to prevent or predict preterm birth. No longer just the "support cells," we now clearly understand that during development glia are key for building a healthy brain. Glial dysfunction is a hallmark of EoP, notably, microgliosis, astrogliosis, and oligodendrocyte injury. Our knowledge of glial biology during development is exponentially expanding but hasn't developed sufficiently for development of effective neuroregenerative therapies. This review summarizes the current state of knowledge for the roles of glia in infants with EoP and its animal models, and a description of known glial-cell interactions in the context of EoP, such as the roles for border-associated macrophages. The field of perinatal medicine is relatively small but has worked passionately to improve our understanding of the etiology of EoP coupled with detailed mechanistic studies of pre-clinical and human cohorts. A primary finding from this review is that expanding our collaborations with computational biologists, working together to understand the complexity of glial subtypes, glial maturation, and the impacts of EoP in the short and long term will be key to the design of therapies that improve outcomes.

Long-term recruitment of peripheral immune cells to brain scars after a neonatal insult

Although brain scars in adults have been extensively studied, there is less data available regarding scar formation during the neonatal period, and the involvement of peripheral immune cells in this process remains unexplored in neonates. Using a murine model of neonatal hypoxic-ischemic encephalopathy (HIE) and confocal microscopy, we characterized the scarring process and examined the recruitment of peripheral immune cells to cortical and hippocampal scars for up to 1 year post-insult. Regional differences in scar formation were observed, including the presence of reticular fibrotic networks in the cortex and perivascular fibrosis in the hippocampus. We identified chemokines with chronically elevated levels in both regions and demonstrated, through a parabiosis-based strategy, the recruitment of lymphocytes, neutrophils, and monocyte-derived macrophages to the scars several weeks after the neonatal insult. After 1 year, however, neutrophils and lymphocytes were absent from the scars. Our data indicate that peripheral immune cells are transient components of HIE-induced brain scars, opening up new possibilities for late therapeutic interventions.

Plasma neuron specific enolase (NSE), tumour necrosis factor-alpha (TNF-α) and soluble IL-2 receptor alpha (sIL-2Rα) levels in children with developmental delay (DD): Use of combined ROC curves to increase their diagnostic value

BACKGROUND

Developmental delay (DD) occurs when children fail to reach developmental milestones in comparison to peers of the same age range. However, there are no valuable biomarkers for the early diagnosis of DD. Since there is no specific marker for screening the disease, we evaluated plasma NSE, TNF-α and sIL2-Rα as potential markers for this purpose.

METHODS

In this cross-sectional randomized case-control study, a total of 174 DD patients and 49 matched elderly controls aged between 2 months and 60 months were recruited. A sensitive enzyme-linked immunosorbent assay and an immunoradiometric assay were used to evaluate the levels of plasma IL-1, IL-6, IL-8, IL-10, sIL2-Rα, TNF-α, and NSE. Statistical analyses using t test, χ2, ANOVA, ROC curves and binary logistic regression models were performed.

RESULTS

In comparison to the control group, the DD group had greater levels of NSE, TNF-α, and sIL2-Rα(p < 0.05). In the binary logistic regression analysis of DD, NSE had an odds ratio (OR) of 1.783 (95 % CI 1.297 to 2.451, p = 0.000), indicating that NSE was an independent risk factor for DD. The plasma TNF-α level was positively correlated with plasma NSE and sIL2-Rα levels in the DD group (r = 0.366 and 0.433, respectively), and the DQ score and plasma sIL2-Rα level in the DD group were positively correlated. The ROC curve revealed that the respective areas under the NSE, TNF-α, and sIL2-Rα ROC curves were 0.9797, 0.9365, and 0.8533, respectively. Moreover, a significant increase in AUC was observed using combined ROC curve analysis.

CONCLUSIONS

Children with DD have significantly altered plasma concentrations of sIL2-Rα, NSE, and TNF-α. NSE, TNF-α and sIL2-Rα can be used as DD blood biomarkers. This information may be helpful in early diagnosis and intervention.

NKG2D knockdown improves hypoxic-ischemic brain damage by inhibiting neuroinflammation in neonatal mice

Hypoxic-ischemic brain damage (HIBD) is a leading cause of neonatal death and neurological dysfunction. Neuroinflammation is identified as one of the crucial pathological mechanisms after HIBD, and natural killer group 2 member D (NKG2D) is reported to be implicated in the pathogenesis of immunoinflammatory diseases. However, the role of NKG2D in neonatal HIBD is seldomly investigated. In this study, a neonatal mice model of HIBD was induced, and the role of the NKG2D in neuroinflammation and brain injury was explored by intracerebroventricular injection of lentivirus to knockdown NKG2D in neonatal mice with HIBD. The results showed that a significant increase in NKG2D protein level in the brain of neonatal mice with HIBD. The NKG2D knockdown in the brain significantly alleviated cerebral infarction, neurobehavioral deficits, and neuronal loss in neuronal HIBD. Moreover, the neuroprotective effect of NKG2D knockdown was associated with inhibition of the activation of microglia and astrocytes, expression of NKG2D ligands (NKG2DLs) and DAP10, and the nuclear translocation of NF-κB p65. Our findings reveal NKG2D knockdown may exert anti-inflammatory and neuroprotective effects in the neonatal mice with HIBD through downregulation of NKG2D/NKG2DLs/DAP10/NF-κB pathway. These results suggest that NKG2D may be a potential target for the treatment of neonatal HIBD.

Maintenance of the synergistic effects of cord blood cells and erythropoietin combination therapy after additional cord blood infusion in children with cerebral palsy: 1-year open-label extension study of randomized placebo-controlled trial

BACKGROUND

This 1-year open-label extension study aimed to identify the persistent synergistic effects of allogeneic umbilical cord blood (UCB) cells and erythropoietin (EPO) in children with cerebral palsy (CP) for up to 2 years.

METHODS

This open-label extension study followed children with CP who were enrolled in the previous randomized, double blind, placebo-controlled trial. The following groups from the first trial were maintained: (A) UCB + EPO, (B) UCB, (C) EPO, and (D) only placebo, and all the participants had continued active rehabilitation. This extended study started 3 months after termination of the first trial, which had a 1-year follow-up duration. All subjects received single additional UCB intravenous infusion at the extension baseline regardless of their initial allocation. Outcome measures were the gross motor performance measure (GMPM), gross motor function measure-66 (GMFM-66), and Bayley scales of infant development-II (BSID-II), which were followed at 3, 6, and 12 months after the extension baseline. Changes in the outcome scores from the baseline values of the previous trial and this study were analysed.

RESULTS

Sixty-nine children (4.29 ± 1.28 years, M:F = 34:35) were included in this study. Each group showed improvements in the outcome measures at 12 months after additional UCB infusion compared to the baseline scores, except for GMFM and GMPM in Group C which were elevated at 3 and 6 months post-therapy. Total subject analyses did not show significant differences in the outcome measures between the four different groups at 3, 6 and 12 months after additional UCB therapy. However, patients with severe dysfunction, whose GMFCS levels were IV and V, revealed a larger improvement of the GMPM score in Group A than in Group D (Ps < 0.05) from the baseline value of the previous trial. The changes in BSID-II mental scale scores were positively correlated with the number of administered total nucleated cells per unit body weight during this one-year extension study period (r = 0.536, P = 0.001).

CONCLUSIONS

These results suggest that when administering UCB to treat patients with CP, combination therapy with EPO is more effective, and the effect might last as long as 2 years, especially in patients with severe impairments.

TRIAL REGISTRATION

CHA Bundang Medical Center IRB, No. 2015-06-093, approved on July 29, 2015, ( https://www.e-irb.com:3443/devlpg/nlpgS200.jsp ), ClinicalTrials.gov, NCT03130816, retrospectively registered on April 27, 2017 ( https://clinicaltrials.gov/ct2/show/NCT03130816?term=NCT03130816&draw=2&rank=1 ).

Selective modulation of monocyte and neutrophil responses with activated protein C in preterm infants

BACKGROUND

Inflammation is associated with many disorders of preterm infants including periventricular leukomalacia, chronic lung disease, and necrotizing enterocolitis. Activated protein c (APC) has shown positive immunomodulatory effects.

OBJECTIVES

We aimed to study neutrophil and monocyte function in response to lipopolysaccharide (LPS) and APC stimulation ex vivo in preterm infants <32 weeks gestation over the first week of life compared to neonatal and adult controls.

METHODS

Peripheral blood was taken on day 1, 3, and 7 and stimulated with LPS in the absence or presence of APC. Expression of toll-like receptor 4 (TLR4) and CD11b and reactive oxygen intermediate (ROI) release from neutrophils and monocytes was examined by flow cytometry.

RESULTS

LPS induced neutrophil ROI in adults and preterm infants and was significantly reduced by APC. Baseline and LPS-induced monocyte ROI production in preterm neonates was increased compared to adult and term controls. Neutrophil TLR4 baseline expression was higher in term controls compared to preterm infants.

CONCLUSION

Increased systemic ROI release in preterm infants may mediate tissue damage, ROI was reduced by APC. However, due to the high risk of hemorrhage further examination of APC mutant forms with anti-inflammatory but decreased anticoagulant properties is merited.

Neuroprotective Action of Tacrolimus before and after Onset of Neonatal Hypoxic-Ischaemic Brain Injury in Rats

(1) Background: Neonatal brain injury can lead to permanent neurodevelopmental impairments. Notably, suppressing inflammatory pathways may reduce damage. To determine the role of neuroinflammation in the progression of neonatal brain injury, we investigated the effect of treating neonatal rat pups with the immunosuppressant tacrolimus at two time points: before and after hypoxic-ischaemic (HI)-induced injury. (2) Methods: To induce HI injury, postnatal day (PND) 10 rat pups underwent single carotid artery ligation followed by hypoxia (8% oxygen, 90 min). Pups received daily tacrolimus (or a vehicle) starting either 3 days before HI on PND 7 (pre-HI), or 12 h after HI (post-HI). Four doses were tested: 0.025, 0.05, 0.1 or 0.25 mg/kg/day. Pups were euthanised at PND 17 or PND 50. (3) Results: All tacrolimus doses administered pre-HI significantly reduced brain infarct size and neuronal loss, increased the number of resting microglia and reduced cellular apoptosis (p < 0.05 compared to control). In contrast, only the highest dose of tacrolimus administered post-HI (0.25 mg/kg/day) reduced brain infarct size (p < 0.05). All doses of tacrolimus reduced pup weight compared to the controls. (4) Conclusions: Tacrolimus administration 3 days pre-HI was neuroprotective, likely mediated through neuroinflammatory and cell death pathways. Tacrolimus post-HI may have limited capacity to reduce brain injury, with higher doses increasing rat pup mortality. This work highlights the benefits of targeting neuroinflammation during the acute injurious period. More specific targeting of neuroinflammation, e.g., via T-cells, warrants further investigation.

Effect of Swiss Ball Stabilization Training on Trunk Control, Abdominal Muscle Thickness, Balance, and Motor Skills of Children With Spastic Cerebral Palsy: A Randomized, Superiority Trial

OBJECTIVES

To compare the effects of Swiss ball stabilization training (SBST) and stable surface stabilization training (SSST) on the trunk control, abdominal muscle thickness, balance, and motor skills of children with spastic cerebral palsy (CWSCP).

DESIGN

Single-blind, randomized superiority trial.

SETTING

General Community and Referral Center.

PARTICIPANTS

Thirty CWSCP, aged 6-12 years, with Gross Motor Function Classification System levels I-III were randomly assigned to the SBST and SSST groups (N=30).

INTERVENTIONS

The participants were randomized to receive either SBST or SSST for 5 weeks, 3 days a week.

OUTCOME MEASURES

The Trunk Control Measurement Scale (TCMS), abdominal muscle thickness, Pediatric Balance Scale (PBS), standing and walking sections of Gross Motor Function Measure (GMFM-88), and mobility section of the Pediatric Evaluation of Disability Inventory (PEDI) were assessed.

RESULTS

After 5 weeks of the intervention and 9 weeks of follow-up, the SBST group showed statistically significant improvements in the TCMS, GMFM-88, PEDI, thickness of the internal oblique muscle at rest and contraction, and thickness of the transverse abdominis muscle at rest and contraction compared with the SSST group (P<.0001). Contrarily, the thickness of the external oblique muscle increased statistically significantly in the SSST group compared with the SBST group after 5 weeks of the intervention and 9 weeks of follow-up both at rest (P<.0001 and P=.0001, respectively) and contraction (P=.015 and P=.017, respectively). No statistically significant difference was found between the groups regarding the PBS score after 5 weeks of intervention.

CONCLUSION

The SBST could improve the trunk control, balance, and motor skills of CWSCP and increase the thickness of local abdominal muscles. Also, SBST was more effective than SSST for CWSCP.

Progress in the treatment of neonatal hypoxic-ischemic encephalopathy with umbilical cord blood mononuclear cells

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common disease among newborns, which is a leading cause of neonatal death and permanent neurological sequelae. Therapeutic hypothermia (TH) is the only method for the treatment of HIE that has been recognized effective clinically at home and abroad, but the efficacy is limited. Recent research suggests that the cord blood-derived mononuclear cells (CB-MNCs), which the refer to blood cells containing one nucleus in the cord blood, exert anti-oxidative, anti-inflammatory, anti-apoptotic effects and play a neuroprotective role in HIE. This review focuses on safety and efficacy, the route of administration, dose, timing and combination treatment of CB-MNCs in HIE.

Sex differences in neonatal brain injury and inflammation

Neonatal brain injury and associated inflammation is more common in males. There is a well-recognised difference in incidence and outcome of neonatal encephalopathy according to sex with a pronounced male disadvantage. Neurodevelopmental differences manifest from an early age in infancy with females having a lower incidence of developmental delay and learning difficulties in comparison with males and male sex has consistently been identified as a risk factor for cerebral palsy in epidemiological studies. Important neurobiological differences exist between the sexes with respect to neuronal injury which are especially pronounced in preterm neonates. There are many potential reasons for these sex differences including genetic, immunological and hormonal differences but there are limited studies of neonatal immune response. Animal models with induced neonatal hypoxia have shown various sex differences including an upregulated immune response and increased microglial activation in males. Male sex is recognized to be a risk factor for neonatal hypoxic ischemic encephalopathy (HIE) during the perinatal period and this review discusses in detail the sex differences in brain injury in preterm and term neonates and some of the potential new therapies with possible sex affects.

A systematic review of immune-based interventions for perinatal neuroprotection: closing the gap between animal studies and human trials

BACKGROUND

Perinatal infection/inflammation is associated with a high risk for neurological injury and neurodevelopmental impairment after birth. Despite a growing preclinical evidence base, anti-inflammatory interventions have not been established in clinical practice, partly because of the range of potential targets. We therefore systematically reviewed preclinical studies of immunomodulation to improve neurological outcomes in the perinatal brain and assessed their therapeutic potential.

METHODS

We reviewed relevant studies published from January 2012 to July 2023 using PubMed, Medline (OvidSP) and EMBASE databases. Studies were assessed for risk of bias using the SYRCLE risk of bias assessment tool (PROSPERO; registration number CRD42023395690).

RESULTS

Forty preclinical publications using 12 models of perinatal neuroinflammation were identified and divided into 59 individual studies. Twenty-seven anti-inflammatory agents in 19 categories were investigated. Forty-five (76%) of 59 studies reported neuroprotection, from all 19 categories of therapeutics. Notably, 10/10 (100%) studies investigating anti-interleukin (IL)-1 therapies reported improved outcome, whereas half of the studies using corticosteroids (5/10; 50%) reported no improvement or worse outcomes with treatment. Most studies (49/59, 83%) did not control core body temperature (a known potential confounder), and 25 of 59 studies (42%) did not report the sex of subjects. Many studies did not clearly state whether they controlled for potential study bias.

CONCLUSION

Anti-inflammatory therapies are promising candidates for treatment or even prevention of perinatal brain injury. Our analysis highlights key knowledge gaps and opportunities to improve preclinical study design that must be addressed to support clinical translation.

The miRNA transcriptome of cerebrospinal fluid in preterm infants reveals the signaling pathways that promote reactive gliosis following cerebral hemorrhage

Introduction

Germinal Matrix-Intraventricular Haemorrhage (GM-IVH) is one of the most common neurological complications in preterm infants, which can lead to accumulation of cerebrospinal fluid (CSF) and is a major cause of severe neurodevelopmental impairment in preterm infants. However, the pathophysiological mechanisms triggered by GM-IVH are poorly understood. Analyzing the CSF that accumulates following IVH may allow the molecular signaling and intracellular communication that contributes to pathogenesis to be elucidated. Growing evidence suggests that miRs, due to their key role in gene expression, have a significant utility as new therapeutics and biomarkers.

Methods

The levels of 2,083 microRNAs (miRs) in 15 CSF samples from 10 infants with IVH were measured using miRNA whole transcriptome sequencing. Gene ontology (GO) and miR family analysis were used to uncover dysregulated signalling which were then validated in vitro in human foetal neural progenitor cells treated with IVH-CSF.

Results

Five hundred eighty-seven miRs were differentially expressed in the CSF extracted at least 2 months after injury, compared to CSF extracted within the first month of injury. GO uncovered key pathways targeted by differentially expressed miRs including the MAPK cascade and the JAK/STAT pathway. Astrogliosis is known to occur in preterm infants, and we hypothesized that this could be due to abnormal CSF-miR signaling resulting in dysregulation of the JAK/STAT pathway - a key controller of astrocyte differentiation. We then confirmed that treatment with IVH-CSF promotes astrocyte differentiation from human fetal NPCs and that this effect could be prevented by JAK/STAT inhibition. Taken together, our results provide novel insights into the CSF/NPCs crosstalk following perinatal brain injury and reveal novel targets to improve neurodevelopmental outcomes in preterm infants.

Potential optimized route for mesenchymal stem cell transplantation in a rat model of cerebral palsy

Cerebral palsy (CP) is a movement and posture disorder that affects over 50 million people worldwide. Human umbilical cord-derived mesenchymal stem cell (hUC-MSC) transplantation has emerged as an attractive therapeutic strategy for CP. The administration route appears to be crucial for hUC-MSC to provide adequate neuroprotection. Wistar rats were given hypoxia-ischemia to make the CP model on postnatal day 5. On postnatal day 21, DiR-labeled hUC-MSC were transplanted into the CP rats by intravenous, intrathecal, and lateral ventricle for cell tracking. Uninfused CP rats served as the negative control. The motor behavioral and pathological alteration was analyzed 11, 25, and 39 days after transplantation to assess motor function, immune inflammation, neurotrophy, and endogenous repair. In vivo imaging tracking techniques revealed that intravenous infusion resulted in fewer transplanted cells in the target brain than intrathecal and lateral ventricle infusion (p＜0.05). Three different routes of hUC-MSC infusion improved the motor function of CP rats (p＜0.05). At 11 days post-infusion, intrathecal infusion outperformed intravenous with a significant neurotrophic and oligodendrocyte maturation effect (p＜0.05). Intrathecal infusion equaled lateral ventricle infusion after 25 days. At 39 days post-infusion, lateral ventricle infusion exceeded intravenous and intrathecal infusion with a significant immunosuppressive effect (p＜0.05). Considering the improved effect and less trauma shown early in the intrathecal infusion, repeated intrathecal administration may ultimately lead to the greatest benefit.

Preterm Birth by Cesarean Section: The Gut-Brain Axis, a Key Regulator of Brain Development

Understanding the long-term functional implications of gut microbial communities during the perinatal period is a bourgeoning area of research. Numerous studies have revealed the existence of a "gut-brain axis" and the impact of an alteration of gut microbiota composition in brain diseases. Recent research has highlighted how gut microbiota could affect brain development and behavior. Many factors in early life such as the mode of delivery or preterm birth could lead to disturbance in the assembly and maturation of gut microbiota. Notably, global rates of cesarean sections (C-sections) have increased in recent decades and remain important when considering premature delivery. Both preterm birth and C-sections are associated with an increased risk of neurodevelopmental disorders such as autism spectrum disorders, with neuroinflammation a major risk factor. In this review, we explore links between preterm birth by C-sections, gut microbiota alteration, and neuroinflammation. We also highlight C-sections as a risk factor for developmental disorders due to alterations in the microbiome.

Depressive-like behavior and impaired synaptic plasticity in the prefrontal cortex as later consequences of prenatal hypoxic-ischemic insult in rats

Perinatal hypoxia-ischemia (HI) is a leading cause of morbidity and mortality among newborns. Infants with HI encephalopathy may experience lasting consequences, such as depression, in adulthood. In this study, we examined depressive-like behavior, neuronal population, and markers of monoaminergic and synaptic plasticity in the prefrontal cortex (PFC) of adolescent rats subjected to a prenatal HI model. Pregnant rats underwent a surgery in which uterine and ovarian blood flow was blocked for 45 min at E18 (HI procedure). Sham-operated subjects were also generated (SH procedure). Behavioral tests were conducted on male and female pups from P41 to P43, and animals were histologically processed or dissected for western blotting at P45. We found that the HI groups consumed less sucrose in the sucrose preference test and remained immobile for longer periods in the forced swim test. Additionally, we observed a significant reduction in neuronal density and PSD95 levels in the HI group, as well as a smaller number of synaptophysin-positive cells. Our results underscore the importance of this model in investigating the effects of HI-induced injuries, as it reproduces an increase in depressive-like behavior and suggests that the HI insult affects circuits involved in mood modulation.

Periventricular Microglia Polarization and Morphological Changes Accompany NLRP3 Inflammasome-Mediated Neuroinflammation after Hypoxic-Ischemic White Matter Damage in Premature Rats

White matter damage (WMD) is a primary cause of cerebral palsy and cognitive impairment in preterm infants, and no effective treatments are available. Microglia are a major component of the innate immune system. When activated, they form typical pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes and regulate myelin development and synapse formation. Therefore, they may play a pivotal role in hypoxic-ischemic (HI) WMD. Herein, we investigated neural inflammation and long-term microglia phenotypic polarization in a neonatal rat model of hypoxia-ischemia-induced WMD and elucidated the underlying pathophysiological processes. We exposed 3-day-old (P3) Sprague-Dawley rats to hypoxia (8% oxygen) for 2.5 hr after unilateral common carotid artery ligation. The activation of NLRP3 inflammatory bodies, microglia M1/M2 polarization, myelination, and synaptic development in our model were monitored 7, 14, and 21 days after birth. In addition, the Morris water maze test was performed on postnatal Day 28. We confirmed myelination disturbance in the periventricular white matter, abnormal synaptic development, and behavioral changes in the periventricular area during the development of HI WMD. In addition, we found an association between the occurrence and development of HI WMD and activation of the NLRP3 inflammasome, microglial M1/M2 polarization, and the release of inflammatory factors. NLRP3 inhibition can play an anti-inflammatory role by inhibiting the differentiation of microglia into the M1 phenotype, thereby improving myelination and synapse formation. In conclusion, microglia are key mediators of the inflammatory response and exhibit continuous phenotypic polarization 7-21 days after HI-induced WMD. This finding can potentially lead to a new treatment regimen targeting the phenotypic polarization of microglia early after HI-induced brain injury.

Resolution of Cerebral Inflammation Following Subarachnoid Hemorrhage

BACKGROUND

Aneurismal subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke that, despite improvement through therapeutic interventions, remains a devastating cerebrovascular disorder that has a high mortality rate and causes long-term disability. Cerebral inflammation after SAH is promoted through microglial accumulation and phagocytosis. Furthermore, proinflammatory cytokine release and neuronal cell death play key roles in the development of brain injury. The termination of these inflammation processes and restoration of tissue homeostasis are of utmost importance regarding the possible chronicity of cerebral inflammation and the improvement of the clinical outcome for affected patients post SAH. Thus, we evaluated the inflammatory resolution phase post SAH and considered indications for potential tertiary brain damage in cases of incomplete resolution.

METHODS

Subarachnoid hemorrhage was induced through endovascular filament perforation in mice. Animals were killed 1, 7 and 14 days and 1, 2 and 3 months after SAH. Brain cryosections were immunolabeled for ionized calcium-binding adaptor molecule-1 to detect microglia/macrophages. Neuronal nuclei and terminal deoxyuridine triphosphate-nick end labeling staining was used to visualize secondary cell death of neurons. The gene expression of various proinflammatory mediators in brain samples was analyzed by quantitative polymerase chain reaction.

RESULTS

We observed restored tissue homeostasis due to decreased microglial/macrophage accumulation and neuronal cell death 1 month after insult. However, the messenger RNA expression levels of  interleukin 6  and  tumor necrosis factor α were still elevated at 1 and 2 months post SAH, respectively. The gene expression of interleukin 1β reached its maximum on day 1, whereas at later time points, no significant differences between the groups were detected.

CONCLUSIONS

By the herein presented molecular and histological data we provide an important indication for an incomplete resolution of inflammation within the brain parenchyma after SAH. Inflammatory resolution and the return to tissue homeostasis represent an important contribution to the disease's pathology influencing the impact on brain damage and outcome after SAH. Therefore, we consider a novel complementary or even superior therapeutic approach that should be carefully rethought in the management of cerebral inflammation after SAH. An acceleration of the resolution phase at the cellular and molecular levels could be a potential aim in this context.

Comparing the efficacy in reducing brain injury of different neuroprotective agents following neonatal hypoxia-ischemia in newborn rats: a multi-drug randomized controlled screening trial

Intrapartum hypoxia-ischemia leading to neonatal encephalopathy (NE) results in significant neonatal mortality and morbidity worldwide, with > 85% of cases occurring in low- and middle-income countries (LMIC). Therapeutic hypothermia (HT) is currently the only available safe and effective treatment of HIE in high-income countries (HIC); however, it has shown limited safety or efficacy in LMIC. Therefore, other therapies are urgently required. We aimed to compare the treatment effects of putative neuroprotective drug candidates following neonatal hypoxic-ischemic (HI) brain injury in an established P7 rat Vannucci model. We conducted the first multi-drug randomized controlled preclinical screening trial, investigating 25 potential therapeutic agents using a standardized experimental setting in which P7 rat pups were exposed to unilateral HI brain injury. The brains were analysed for unilateral hemispheric brain area loss after 7 days survival. Twenty animal experiments were performed. Eight of the 25 therapeutic agents significantly reduced brain area loss with the strongest treatment effect for Caffeine, Sonic Hedgehog Agonist (SAG) and Allopurinol, followed by Melatonin, Clemastine, ß-Hydroxybutyrate, Omegaven, and Iodide. The probability of efficacy was superior to that of HT for Caffeine, SAG, Allopurinol, Melatonin, Clemastine, ß-hydroxybutyrate, and Omegaven. We provide the results of the first systematic preclinical screening of potential neuroprotective treatments and present alternative single therapies that may be promising treatment options for HT in LMIC.

Immuno-epigenetic signature derived in saliva associates with the encephalopathy of prematurity and perinatal inflammatory disorders

BACKGROUND

Preterm birth is closely associated with a phenotype that includes brain dysmaturation and neurocognitive impairment, commonly termed Encephalopathy of Prematurity (EoP), of which systemic inflammation is considered a key driver. DNA methylation (DNAm) signatures of inflammation from peripheral blood associate with poor brain imaging outcomes in adult cohorts. However, the robustness of DNAm inflammatory scores in infancy, their relation to comorbidities of preterm birth characterised by inflammation, neonatal neuroimaging metrics of EoP, and saliva cross-tissue applicability are unknown.

METHODS

Using salivary DNAm from 258 neonates (n = 155 preterm, gestational age at birth 23.28 - 34.84 weeks, n = 103 term, gestational age at birth 37.00 - 42.14 weeks), we investigated the impact of a DNAm surrogate for C-reactive protein (DNAm CRP) on brain structure and other clinically defined inflammatory exposures. We assessed i) if DNAm CRP estimates varied between preterm infants at term equivalent age and term infants, ii) how DNAm CRP related to different types of inflammatory exposure (maternal, fetal and postnatal) and iii) whether elevated DNAm CRP associated with poorer measures of neonatal brain volume and white matter connectivity.

RESULTS

Higher DNAm CRP was linked to preterm status (-0.0107 ± 0.0008, compared with -0.0118 ± 0.0006 among term infants; p < 0.001), as well as perinatal inflammatory diseases, including histologic chorioamnionitis, sepsis, bronchopulmonary dysplasia, and necrotising enterocolitis (OR range |2.00 | to |4.71|, p < 0.01). Preterm infants with higher DNAm CRP scores had lower brain volume in deep grey matter, white matter, and hippocampi and amygdalae (β range |0.185| to |0.218|). No such associations were observed for term infants. Association magnitudes were largest for measures of white matter microstructure among preterms, where elevated epigenetic inflammation associated with poorer global measures of white matter integrity (β range |0.206| to |0.371|), independent of other confounding exposures.

CONCLUSIONS

Inflammatory-related DNAm captures the allostatic load of inflammatory burden in preterm infants. Such DNAm measures complement biological and clinical metrics when investigating the determinants of neurodevelopmental differences.

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

Alpha1-antitrypsin protects the immature mouse brain following hypoxic-ischemic injury

Introduction: Preterm brain injury often leads to lifelong disabilities affecting both cognitive and motor functions, and effective therapies are limited. Alpha1-antitrypsin (AAT), an endogenous inhibitor of serine proteinases with anti-inflammatory, anti-apoptotic, and cytoprotective properties, might be beneficial in treating preterm brain injury. The aim of this study was to investigate whether AAT has neuroprotective effects in a mouse preterm brain injury model. Methods: Preterm brain injury was induced on postnatal day 5, and mouse pups' right common carotid arteries were cut between two ligations followed by hypoxia induction. Brain injury was evaluated through immunohistochemistry staining and magnetic resonance imaging. Fluoro-Jade B and immunohistochemistry staining were performed to investigate the neuronal cell death and blood-brain barrier (BBB) permeability. The motor function and anxiety-like behaviors were revealed by CatWalk gait analysis and the open field test. Results: After hypoxia-ischemia (HI) insult, brain injury was alleviated by AAT treatment, and this was accompanied by reduced BBB permeability, reduced neuronal cell death and caspase-3 activation, and inhibition of microglia activation. In addition, AAT administration significantly improved HI-induced motor function deficiencies in mice. The neuroprotective effect of AAT was more pronounced in male mice. Conclusion: AAT treatment is neuroprotective against preterm brain injury in neonatal mice, and the effect is more pronounced in males.

Insight into the Neuroprotective Effect of Genistein-3'-Sodium Sulfonate Against Neonatal Hypoxic-Ischaemic Brain Injury in Rats by Bioinformatics

Therapeutic hypothermia (TH) is the only intervention approved for the treatment of neonatal hypoxic-ischaemic encephalopathy (HIE), but its treatment window is narrow (within 6 h after birth), and its efficacy is not ideal. Thus, alternative treatments are urgently needed. Our previous studies showed that genistein-3'-sodium sulfonate (GSS), a derivative of genistein (Gen), has a strong neuroprotective effect in rats with ischaemic stroke, but its role in HIE is unclear. A hypoxia-ischaemia (HI) brain injury model was established in neonatal male Sprague‒Dawley (SD) rats. Twenty-four hours after reperfusion, rats treated with GSS were assessed for cerebral infarction, neurological function, and neuronal damage. RNA-Seq and bioinformatics analysis were used to explore differentially expressed genes (DEGs) and regulated signalling pathways, which were subsequently validated by Western blotting and immunofluorescence. In this study, we found that GSS not only significantly reduced the size of brain infarcts and alleviated nerve damage in rats with HIE but also inhibited neuronal loss and degeneration in neonatal rats with HIE. A total of 2170 DEGs, of which 1102 were upregulated and 1068 were downregulated, were identified in the GSS group compared with the HI group. In an analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) categories, the downregulated DEGs were significantly enriched in the pathways "Phagosome", "NF-κB signalling", and "Complement and coagulation cascades", amongst others. Meanwhile, the upregulated DEGs were significantly enriched in the pathways "Neurodegeneration", "Glutamatergic synapse", and "Calcium signalling pathway", amongst others. These results indicate that GSS intervenes in the process of HIE-induced brain injury by participating in multiple pathways, which suggests potential candidate drugs for the treatment of HIE.

Persistent Inflammation in Cerebral Palsy: Pathogenic Mediator or Comorbidity? A Scoping Review

Research has established inflammation in the pathogenesis of brain injury and the risk of developing cerebral palsy (CP). However, it is unclear if inflammation is solely pathogenic and primarily contributes to the acute phase of injury, or if inflammation persists with consequence in CP and may therefore be considered a comorbidity. We conducted a scoping review to identify studies that analyzed inflammatory biomarkers in CP and discuss the role of inflammation in the pathogenesis of CP and/or as a comorbidity. Twelve included studies reported a range of analytes, methods and biomarkers, including indicators of inflammatory status, immune function and genetic changes. The majority of controlled studies concluded that one or more systemic biomarkers of inflammation were significantly different in CP versus controls; most commonly serum or plasma cytokines such as tumor necrosis factor, Interleukin (IL)-6 and IL-10. In addition, differences in inflammation were noted in distinct subgroups of CP (e.g., those with varying severity). The available evidence supports the pathogenic role of inflammation and its ongoing role as a comorbidity of CP. This review shows that inflammation may persist for decades, driving functional impairment across development and into adulthood. However, inflammation is complex, thus further research will increase our understanding.

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.

Neuroprotective therapies in the NICU in term infants: present and future

Outcomes of neonatal encephalopathy (NE) have improved since the widespread implementation of therapeutic hypothermia (TH) in high-resource settings. While TH for NE in term and near-term infants has proven beneficial, 30-50% of infants with moderate-to-severe NE treated with TH still suffer death or significant impairments. There is therefore a critical need to find additional pharmacological and non-pharmacological interventions that improve the outcomes for these children. There are many potential candidates; however, it is unclear whether these interventions have additional benefits when used with TH. Although primary and delayed (secondary) brain injury starting in the latent phase after HI are major contributors to neurodisability, the very late evolving effects of tertiary brain injury likely require different interventions targeting neurorestoration. Clinical trials of seizure management and neuroprotection bundles are needed, in addition to current trials combining erythropoietin, stem cells, and melatonin with TH. IMPACT: The widespread use of therapeutic hypothermia (TH) in the treatment of neonatal encephalopathy (NE) has reduced the associated morbidity and mortality. However, 30-50% of infants with moderate-to-severe NE treated with TH still suffer death or significant impairments. This review details the pathophysiology of NE along with the evidence for the use of TH and other beneficial neuroprotective strategies used in term infants. We also discuss treatment strategies undergoing evaluation at present as potential adjuvant treatments to TH in NE.

Feasibility of Using Joystick-Operated Ride-on-Toys to Promote Upper Extremity Function in Children With Cerebral Palsy: A Pilot Study

PURPOSE

To evaluate the feasibility of implementation, acceptance, and perceived efficacy of a joystick-operated ride-on-toy intervention to promote upper extremity (UE) function in 3- to 14-year-old children with hemiplegic cerebral palsy.

METHODS

Exit questionnaires were collected from children, caregivers, and clinicians/camp staff following a 3-week ride-on-toy training program incorporated within a summer camp for children with hemiplegic cerebral palsy. Training encouraged children to use their affected UE to maneuver the ride-on-toy. Questionnaires included Likert scale and open-ended questions to assess enjoyment, acceptance, feasibility, and perceived efficacy of the training.

RESULTS

All stakeholder groups indicated that the training was enjoyable. Clinicians/staff and caregivers indicated that the training increased children's motivation to use their affected UE and reported perceived improvements in UE movement control and function following training.

CONCLUSIONS

Our promising preliminary findings call for future research to systematically assess the efficacy of ride-on-toys to promote UE control and function in children with hemiplegic cerebral palsy.Supplemental Digital Content 1 video abstract, available at: http://links.lww.com/PPT/A404.

NT-Pro-BNP and echocardiography for the early assessment of cardiovascular dysfunction in neonates with sepsis

To investigate the predictive manner of N-terminal fragment of brain natriuretic peptide (NT-Pro-BNP) and echocardiography in the early assessment of cardiovascular dysfunction (CVD) in neonates with sepsis, we recruited 108 neonates with sepsis in intensive care units and divided them into a sepsis with CVD (sepsis + CVD) group (n = 48) and a sepsis only group (n = 60). Neonates with other infections (n = 65) constituted the control group. Clinical, laboratory, and bedside echocardiography findings were evaluated. Compared to both the sepsis only and control groups, the sepsis + CVD group showed an earlier onset of symptoms [52.94 (0-185.6) h], higher NT-Pro-BNP levels (P = .02), a higher Tei index (0.52 + 0.03; P = .03), and lower ejection fraction (62.61% ± 12.31%, P < .05). Compared to the control group, the sepsis + CVD group exhibited hematogenous etiology (P < .05), lower albumin (ALB) levels (P = .04), lower white blood cell counts (P = .03), a higher high-sensitivity C-reactive protein/ALB ratio, and a larger right-ventricle-inner diameter (10.74 + 2.42 mm; P = .01). CVD in the septic neonates could be predicted by either NT-Pro-BNP levels (cut-off: 12,291.5 pg/L; sensitivity, 80%; specificity, 79%; area under the curve-receiver operating characteristic, 0.81) or Tei index (cut-off: 0.45; sensitivity, 74%; specificity, 77%; area under the curve-receiver operating characteristic, 0.78). NT-Pro-BNP levels and echocardiography can be used to determine early onset of CVD in neonatal sepsis, which facilitates timely pharmacological interventions and treatment.

A unique cerebellar pattern of microglia activation in a mouse model of encephalopathy of prematurity

Preterm infants often show pathologies of the cerebellum, which are associated with impaired motor performance, lower IQ and poor language skills at school ages. Using a mouse model of inflammation-induced encephalopathy of prematurity driven by systemic administration of pro-inflammatory IL-1β, we sought to uncover causes of cerebellar damage. In this model, IL-1β is administered between postnatal day (P) 1 to day 5, a timing equivalent to the last trimester for brain development in humans. Structural MRI analysis revealed that systemic IL-1β treatment induced specific reductions in gray and white matter volumes of the mouse cerebellar lobules I and II (5% false discovery rate [FDR]) from P15 onwards. Preceding these MRI-detectable cerebellar volume changes, we observed damage to oligodendroglia, with reduced proliferation of OLIG2+ cells at P10 and reduced levels of the myelin proteins myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) at P10 and P15. Increased density of IBA1+ cerebellar microglia were observed both at P5 and P45, with evidence for increased microglial proliferation at P5 and P10. Comparison of the transcriptome of microglia isolated from P5 cerebellums and cerebrums revealed significant enrichment of pro-inflammatory markers in microglia from both regions, but cerebellar microglia displayed a unique type I interferon signaling dysregulation. Collectively, these data suggest that perinatal inflammation driven by systemic IL-1β leads to specific cerebellar volume deficits, which likely reflect oligodendrocyte pathology downstream of microglial activation. Further studies are now required to confirm the potential of protective strategies aimed at preventing sustained type I interferon signaling driven by cerebellar microglia as an important therapeutic target.

Cerebral Oxygenation and Metabolism After Hypoxia-Ischemia

Perinatal hypoxia-ischemia (HI) is still a significant contributor to mortality and adverse neurodevelopmental outcomes in term and preterm infants. HI brain injury evolves over hours to days, and involves complex interactions between the endogenous protective and pathological processes. Understanding the timing of evolution of injury is vital to guide treatment. Post-HI recovery is associated with a typical neurophysiological profile, with stereotypic changes in cerebral perfusion and oxygenation. After the initial recovery, there is a delayed, prolonged reduction in cerebral perfusion related to metabolic suppression, followed by secondary deterioration with hyperperfusion and increased cerebral oxygenation, associated with altered neurovascular coupling and impaired cerebral autoregulation. These changes in cerebral perfusion are associated with the stages of evolution of injury and injury severity. Further, iatrogenic factors can also affect cerebral oxygenation during the early period of deranged metabolism, and improving clinical management may improve neuroprotection. We will review recent evidence that changes in cerebral oxygenation and metabolism after HI may be useful biomarkers of prognosis.

Elevated serum IL-10 is associated with severity of neonatal encephalopathy and adverse early childhood outcomes

BACKGROUND

Neonatal encephalopathy (NE) contributes substantially to child mortality and disability globally. We compared cytokine profiles in term Ugandan neonates with and without NE, with and without perinatal infection or inflammation and identified biomarkers predicting neonatal and early childhood outcomes.

METHODS

In this exploratory biomarker study, serum IL-1α, IL-6, IL-8, IL-10, TNFα, and VEGF (<12 h) were compared between NE and non-NE infants with and without perinatal infection/inflammation. Neonatal (severity of NE, mortality) and early childhood (death or neurodevelopmental impairment to 2.5 years) outcomes were assessed. Predictors of outcomes were explored with multivariable linear and logistic regression and receiver-operating characteristic analyses.

RESULTS

Cytokine assays on 159 NE and 157 non-NE infants were performed; data on early childhood outcomes were available for 150 and 129, respectively. NE infants had higher IL-10 (p < 0.001), higher IL-6 (p < 0.017), and lower VEGF (p < 0.001) levels. Moderate and severe NE was associated with higher IL-10 levels compared to non-NE infants (p < 0.001). Elevated IL-1α was associated with perinatal infection/inflammation (p = 0.013). Among NE infants, IL-10 predicted neonatal mortality (p = 0.01) and adverse early childhood outcome (adjusted OR 2.28, 95% CI 1.35-3.86, p = 0.002).

CONCLUSIONS

Our findings support a potential role for IL-10 as a biomarker for adverse outcomes after neonatal encephalopathy.

IMPACT

Neonatal encephalopathy is a common cause of child death and disability globally. Inflammatory cytokines are potential biomarkers of encephalopathy severity and outcome. In this Ugandan health facility-based cohort, neonatal encephalopathy was associated with elevated serum IL-10 and IL-6, and reduced VEGF at birth. Elevated serum IL-10 within 12 h after birth predicted severity of neonatal encephalopathy, neonatal mortality, and adverse early childhood developmental outcomes, independent of perinatal infection or inflammation, and provides evidence to the contribution of the inflammatory processes. Our findings support a role for IL-10 as a biomarker for adverse outcomes after neonatal encephalopathy in a sub-Saharan African cohort.

Connexins, Pannexins and Gap Junctions in Perinatal Brain Injury

Perinatal brain injury secondary to hypoxia-ischemia and/or infection/inflammation remains a major cause of disability. Therapeutic hypothermia significantly improves outcomes, but in randomized controlled trials nearly half of infants still died or survived with disability, showing that additional interventions are needed. There is growing evidence that brain injury spreads over time from injured to previously uninjured regions of the brain. At least in part, this spread is related to opening of connexin hemichannels and pannexin channels, both of which are large conductance membrane channels found in many brain cells. Opening of these membrane channels releases adenosine triphosphate (ATP), and other neuroactive molecules, into the extracellular space. ATP has an important role in normal signaling, but pathologically can trigger the assembly of the multi-protein inflammasome complex. The inflammasome complex promotes activation of inflammatory caspases, and release of inflammatory cytokines. Overall, the connexin hemichannel appears to play a primary role in propagation of injury and chronic disease, and connexin hemichannel blockade has been shown to be neuroprotective in multiple animal models. Thus, there is potential for some blockers of connexin or pannexin channels to be developed into targeted interventions that could be used in conjunction with or separate to therapeutic hypothermia.

Relationship Between TNF-α and the Risk of Cerebral Palsy: A Systematic Review and Meta-Analysis

Objective

We performed a meta-analysis to investigate the relationship between blood tumor necrosis factor-alpha (TNF-α) levels and the risk of cerebral palsy (CP) in children.

Methods

PubMed, Web of Science, Cochrane Library and Ovid databases were searched from the date of database inception to 26 April 2022. Data were extracted and pooled from observational studies related to TNF-α and the risk of CP in children. Quality was assessed using the Newcastle-Ottawa Scale. We used the inverse variance method with a random-effects model to estimate the odds ratios with 95% confidence intervals (CIs), and stratified analyses and sensitivity analysis were utilized to analyse heterogeneity.

Results

Nine studies with 1,117 cases and 3,563 controls were included in our meta-analysis. The quality of the literature was good, and no publication bias was noted. According to the random-effects model, blood TNF-α levels were associated with the risk of CP (OR 1.82; 95% CI, 1.25–2.66) in a heterogeneous set of studies (I2 = 81.2%, p = 0.000).

Conclusion

Our findings indicate that elevated TNF-α levels in the blood are associated with an increased risk of CP. The association of TNF-α with CP requires further investigation.

Melatonin Administration from 2000 to 2020 to Human Newborns with Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is the main cause of long-term neurodevelopmental morbidity in term born infants worldwide. Melatonin is a hormone with antioxidant and anti-inflammatory effects that make it a promising molecule for the treatment of perinatal asphyxia. Probably, the synergistic use of hypothermia associated with melatonin treatment may improve the neurological outcome in infants with HIE. In the past 20 years, the efficacy of melatonin in reducing oxidative stress has been demonstrated in animals; however, clinical trials with sufficient sample size of newborns are lacking to date. Since in 2000 we were among the first to study the neuroprotective properties of melatonin on infants, in this review, we want to summarize the advantages and limitations of the investigations conducted to date. KEY POINTS: · HIE is the main cause of morbidity in term born infants worldwide.. · Melatonin is a promising molecule for the treatment of perinatal asphyxia.. · This review summarizes advantages and limitations of the investigations conducted on melatonin..

Rationale for the Use of Cord Blood in Hypoxic-Ischaemic Encephalopathy

Hypoxic-ischaemic encephalopathy (HIE) is a severe complication of asphyxia at birth. Therapeutic hypothermia, the standard method for HIE prevention, is effective in only 50% of the cases. As the understanding of the immunological basis of these changes increases, experiments have begun with the use of cord blood (CB) because of its neuroprotective properties. Mechanisms for the neuroprotective effects of CB stem cells include antiapoptotic and anti-inflammatory actions, stimulation of angiogenesis, production of trophic factors, and mitochondrial donation. In several animal models of HIE, CB decreased oxidative stress, cell death markers, CD4+ T cell infiltration, and microglial activation; restored normal brain metabolic activity; promoted neurogenesis; improved myelination; and increased the proportion of mature oligodendrocytes, neuron numbers in the motor cortex and somatosensory cortex, and brain weight. These observations translate into motor strength, limb function, gait, and cognitive function and behaviour. In humans, the efficacy and safety of CB administration were reported in a few early clinical studies which confirmed the feasibility and safety of this intervention for up to 10 years. The results of these studies showed an improvement in the developmental outcomes over hypothermia. Two phase-2 clinical studies are ongoing under the United States regulations, namely one controlled study and one blinded study.

Mitochondrial dynamics in the neonatal brain - a potential target following injury?

The impact of birth asphyxia and its sequelae, hypoxic–ischaemic (HI) brain injury, is long-lasting and significant, both for the infant and for their family. Treatment options are limited to therapeutic hypothermia, which is not universally successful and is unavailable in low resource settings. The energy deficits that accompany neuronal death following interruption of blood flow to the brain implicate mitochondrial dysfunction. Such HI insults trigger mitochondrial outer membrane permeabilisation leading to release of pro-apoptotic proteins into the cytosol and cell death. More recently, key players in mitochondrial fission and fusion have been identified as targets following HI brain injury. This review aims to provide an introduction to the molecular players and pathways driving mitochondrial dynamics, the regulation of these pathways and how they are altered following HI insult. Finally, we review progress on repurposing or repositioning drugs already approved for other indications, which may target mitochondrial dynamics and provide promising avenues for intervention following brain injury. Such repurposing may provide a mechanism to fast-track, low-cost treatment options to the clinic.

Erythropoietin as a Neuroprotective Drug for Newborn Infants: Ten Years after the First Use

Protective strategies against perinatal brain injury represent a major challenge for modern neonatology. Erythropoietin (Epo) enhances endogenous mechanisms of repair and angiogenesis. In order to analyse the newest evidence on the role of Epo in prematurity, hypoxic ischemic encephalopathy (HIE) and perinatal stroke, a critical review using 2020 PRISMA statement guidelines was conducted. This review uncovered 26 clinical trials examining the use of Epo for prematurity and brain injury-related outcomes. The effects of Epo on prematurity were analysed in 16 clinical trials. Erythropoietin was provided until 32–35 weeks of corrected postnatal age with a dosage between 500–3000 UI/kg/dose. Eight trials reported the Epo effects on HIE term newborn infants: Erythropoietin was administered in the first weeks of life, at different multiple doses between 250–2500 UI/kg/dose, as either an adjuvant therapy with hypothermia or a substitute for hypothermia. Two trials investigated Epo effects in perinatal stroke. Erythropoietin was administered at a dose of 1000 IU/kg for three days. No beneficial effect in improving morbidity was observed after Epo administration in perinatal stroke. A positive effect on neurodevelopmental outcome seems to occur when Epo is used as an adjuvant therapy with hypothermia in the HIE newborns. Administration of Epo in preterm infants still presents inconsistencies with regard to neurodevelopmental outcome. Clinical trials show significant differences mainly in target population and intervention scheme. The identification of specific markers and their temporal expression at different time of recovery after hypoxia-ischemia in neonates might be implemented to optimize the therapeutic scheme after hypoxic-ischemic injury in the developing brain. Additional studies on tailored regimes, accounting for the risk stratification of brain damage in newborns, are required.

Asymmetry Index Evaluation of Cerebral Volume and Cerebral Blood Flow in Neonatal Hypoxic–Ischemic Encephalopathy

The aim of the present study was to longitudinally evaluate the differences in cerebral volume and cerebral blood flow (CBF) on the right and left sides in rats with neonatal hypoxic–ischemic encephalopathy (HIE) using magnetic resonance imaging and the Rice–Vannucci model. Unilateral ligation of the left common carotid artery was performed on 8-day-old rats, followed by mild (1 h, n = 6) or severe (2 h, n = 7) hypoxic exposure. T2-weighted (T2W) and CBF images were obtained at 1 h and 1, 3, and 7 days following the HI insult. The cerebral volume (Vlesion and Vcontrol), CBF in both hemispheres (lesion and control sides), and asymmetry indices of the cerebral volume (AIvolume) and CBF (AICBF) were calculated for each group. Slight hyperintensities were noted in the lesion-side hemispheres on T2W images at 1 h and 1 day in both groups, as were pronounced hyperintensities at days 3 and 7 in the severe group. AIvolume was positive (Vlesion > Vcontrol) in the mild and severe groups until days 1 and 3, respectively, and changed to negative on days 3 and 7 in the mild and severe groups. These results suggest that the prolonged positive AIvolume prior to day 3 in the severe group was caused by long-term cell swelling following severe HI insult.

C3a Receptor Signaling Inhibits Neurodegeneration Induced by Neonatal Hypoxic-Ischemic Brain Injury

Hypoxic-ischemic neonatal encephalopathy due to perinatal asphyxia is the leading cause of brain injury in newborns. Clinical data suggest that brain inflammation induced by perinatal insults can persist for years. We previously showed that signaling through the receptor for complement peptide C3a (C3aR) protects against cognitive impairment induced by experimental perinatal asphyxia. To investigate the long-term neuropathological effects of hypoxic-ischemic injury to the developing brain and the role of C3aR signaling therein, we subjected wildtype mice, C3aR deficient mice, and mice expressing biologically active C3a in the CNS to mild hypoxic-ischemic brain injury on postnatal day 9. We found that such injury triggers neurodegeneration and pronounced reactive gliosis in the ipsilesional hippocampus both of which persist long into adulthood. Transgenic expression of C3a in reactive astrocytes reduced hippocampal neurodegeneration and reactive gliosis. In contrast, neurodegeneration and microglial cell density increased in mice lacking C3aR. Intranasal administration of C3a for 3 days starting 1 h after induction of hypoxia-ischemia reduced neurodegeneration and reactive gliosis in the hippocampus of wildtype mice. We conclude that neonatal hypoxic-ischemic brain injury leads to long-lasting neurodegeneration. This neurodegeneration is substantially reduced by treatment with C3aR agonists, conceivably through modulation of reactive gliosis.

The Effects of In Utero Fetal Hypoxia and Creatine Treatment on Mitochondrial Function in the Late Gestation Fetal Sheep Brain

Near-term acute hypoxia in utero can result in significant fetal brain injury, with some brain regions more vulnerable than others. As mitochondrial dysfunction is an underlying feature of the injury cascade following hypoxia, this study is aimed at characterizing mitochondrial function at a region-specific level in the near-term fetal brain after a period of acute hypoxia. We hypothesized that regional differences in mitochondrial function would be evident, and that prophylactic creatine treatment would mitigate mitochondrial dysfunction following hypoxia; thereby reducing fetal brain injury. Pregnant Border-Leicester/Merino ewes with singleton fetuses were surgically instrumented at 118 days of gestation (dGa; term is ~145 dGA). A continuous infusion of either creatine (n = 15; 6 mg/kg/h) or isovolumetric saline (n = 16; 1.5 ml/kg/h) was administered to the fetuses from 121 dGa. After 10 days of infusion, a subset of fetuses (8 saline-, 7 creatine-treated) were subjected to 10 minutes of umbilical cord occlusion (UCO) to induce a mild global fetal hypoxia. At 72 hours after UCO, the fetal brain was collected for high-resolution mitochondrial respirometry and molecular and histological analyses. The results show that the transient UCO-induced acute hypoxia impaired mitochondrial function in the hippocampus and the periventricular white matter and increased the incidence of cell death in the hippocampus. Creatine treatment did not rectify the changes in mitochondrial respiration associated with hypoxia, but there was a negative relationship between cell death and creatine content following treatment. Irrespective of UCO, creatine increased the proportion of cytochrome c bound to the inner mitochondrial membrane, upregulated the mRNA expression of the antiapoptotic gene Bcl2, and of PCG1-α, a driver of mitogenesis, in the hippocampus. We conclude that creatine treatment prior to brief, acute hypoxia does not fundamentally modify mitochondrial respiratory function, but may improve mitochondrial structural integrity and potentially increase mitogenesis and activity of antiapoptotic pathways.

Src Family Kinases Inhibition Ameliorates Hypoxic-Ischemic Brain Injury in Immature Rats

Hypoxic-ischemic (HI) injury is one of the initial factors contributing to neonatal brain injury. Src family kinases (SFKs) are considered to act as molecular hubs for N-methyl-d-aspartate receptor (NMDAR) regulation and participate in the HI injury process. The objectives of this study were to evaluate the levels of phospho-Src (p-Src), the relationship between NMDARs and SFKs, and the effects of SFK inhibition on an immature rat HI brain injury model. The model was induced in 3-day-old Sprague–Dawley rats using the Rice-Vannucci model operation. The level of p-Src was evaluated using Western blotting. The association of NMDARs with SFKs was detected using Western blotting and coimmunoprecipitation. After intraperitoneal injection of 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo [3,4-d] pyrimidine (PP2), an SFK-selective inhibitor, neuropathological changes were observed by performing H&E and immunofluorescence staining, and the neurological functions were assessed using the following behavioral tests: modified neurological severity score, open field test, and Morris water maze test. The levels of p-Src first decreased at 0 h after injury, increased at 2 h after injury, and continuously decreased from 6 h to 3 days. Along with the increased p-Src levels observed at 2 h after injury, the phosphorylation of NMDAR subunit NR2B at tyrosine 1472 was increased. Following the administration of PP2, the increased p-Src and NMDAR-2B levels detected at 2 h after injury were decreased, and tissue injury and myelin basic protein expression were improved at 7 days after injury. The PP2 intervention improved the performance of injured rats on behavioral tests. In conclusion, we determined the patterns of p-Src expression after HI brain injury in immature rats and showed a relationship with the activated NMDA receptor. The inhibition of p-Src ameliorates neuropathological changes and damages neurological functions induced by HI injury.

Peripheral immune cells and perinatal brain injury: a double-edged sword?

Perinatal brain injury is the leading cause of neurological mortality and morbidity in childhood ranging from motor and cognitive impairment to behavioural and neuropsychiatric disorders. Various noxious stimuli, including perinatal inflammation, chronic and acute hypoxia, hyperoxia, stress and drug exposure contribute to the pathogenesis. Among a variety of pathological phenomena, the unique developing immune system plays an important role in the understanding of mechanisms of injury to the immature brain. Neuroinflammation following a perinatal insult largely contributes to evolution of damage to resident brain cells, but may also be beneficial for repair activities. The present review will focus on the role of peripheral immune cells and discuss processes involved in neuroinflammation under two frequent perinatal conditions, systemic infection/inflammation associated with encephalopathy of prematurity (EoP) and hypoxia/ischaemia in the context of neonatal encephalopathy (NE) and stroke at term. Different immune cell subsets in perinatal brain injury including their infiltration routes will be reviewed and critical aspects such as sex differences and maturational stage will be discussed. Interactions with existing regenerative therapies such as stem cells and also potentials to develop novel immunomodulatory targets are considered. IMPACT: Comprehensive summary of current knowledge on the role of different immune cell subsets in perinatal brain injury including discussion of critical aspects to be considered for development of immunomodulatory therapies.

Is late prevention of cerebral palsy in extremely preterm infants plausible?

Preterm birth continues to be associated with neurodevelopmental problems including cerebral palsy. Cystic white matter injury is still the major neuropathology underlying cerebral palsy, affecting 1-3% of preterm infants. Although rates have gradually fallen over time, the pathogenesis and evolution of cystic white matter injury are still poorly understood. Hypoxia-ischemia (HI) remains an important contributor yet there is no established treatment to prevent injury. Clinically, serial ultrasound and magnetic resonance imaging studies typically show delayed development of cystic lesions 2 to 4 weeks after birth. This raises the important and unresolved question as to whether this represents slow evolution of injury occurring around the time of birth, or repeated injury over many weeks after birth. There is increasing evidence that tertiary injury after HI can contribute to impairment of white and grey matter maturation. In the present review, we discuss preclinical evidence that severe, cystic white matter injury can evolve for many weeks after acute HI and is associated with microglia activity. This suggests the intriguing hypothesis that the tertiary phase of injury is not as subtle as often thought and that there may be a window of therapeutic opportunity for one to two weeks after hypoxic-ischemic injury to prevent delayed cystic lesions and so further reduce the risk of cerebral palsy after preterm birth.

Cortisol Levels in Infants with Central Coordination Disorders during Vojta Therapy

Background: Due to the decrease in the percentage of perinatal mortality, which is one of the Millennium Development Goals, the number of children with a central coordination disorder (CCD) has increased, present in up to 40% of premature babies. Neurodevelopmental disorders detected in the diagnostic process require early interventions that will eliminate or overcome existing dysfunctions. These treatments often cause discomfort in the infant, which induces insecurity and activation of basic defense mechanisms. The aim of the work is to assess changes in cortisol concentration in infants treated with the Vojta method. Methods and findings: The study included 35 children with CCD aged between three and nine months. The participants had no comorbidities that could have affected the obtained results. The activities were planned to occur in three stages: 1. Collection of a saliva sample directly before the physiotherapy appointment. 2. Collection of saliva immediately after rehabilitation. 3. Collection of saliva 20 min after the end of rehabilitation. The physiotherapeutic intervention included the assessment of seven reactions of the body position in space according to Vojta and the conduct of a therapeutic session consisting of the first phase of rotation and creeping reflex according to Vojta. The concentration of free cortisol in saliva was assessed with LC-MS/MS. In the first measurement, none of the children presented an excess of the normative concentration of cortisol. The cortisol measurement performed directly after rehabilitation showed above-normative values in three children. In the third measurement, all of the children presented a decreased concentration of free cortisol. The analysis (paired two-tailed t-test, p < 0.05) showed statistically significant differences between particular stages of the measurements. The analysis of the scores obtained in the second measurement showed the concentration of scores in the area of “normal” at a level of 0.83 (normal concentration) and the area “above normal” at the level of 0.005 (very weak concentration). Based on the analysis of significance of the obtained scores, it was found that the result was not accidental, and the Vojta method used in the treatment of children with CCD was suitable. Conclusions: Here, for the first time, we presented how Vojta therapy was correlated with cortisol levels among children with a central coordination disorder.