Open-Spaced Ridged Hydrogel Scaffolds Containing TiO2-Self-Assembled Monolayer of Phosphonates Promote Regeneration and Recovery Following Spinal Cord Injury.

The spinal cord has a poor ability to regenerate after an injury, which may be due to cell loss, cyst formation, inflammation, and scarring. A promising approach to treating a spinal cord injury (SCI) is the use of biomaterials. We have developed a novel hydrogel scaffold fabricated from oligo(poly(ethylene glycol) fumarate) (OPF) as a 0.08 mm thick sheet containing polymer ridges and a cell-attractive surface on the other side. When the cells are cultured on OPF via chemical patterning, the cells attach, align, and deposit ECM along the direction of the pattern. Animals implanted with the rolled scaffold sheets had greater hindlimb recovery compared to that of the multichannel scaffold control, which is likely due to the greater number of axons growing across it. The immune cell number (microglia or hemopoietic cells: 50-120 cells/mm2 in all conditions), scarring (5-10% in all conditions), and ECM deposits (Laminin or Fibronectin: approximately 10-20% in all conditions) were equal in all conditions. Overall, the results suggest that the scaffold sheets promote axon outgrowth that can be guided across the scaffold, thereby promoting hindlimb recovery. This study provides a hydrogel scaffold construct that can be used in vitro for cell characterization or in vivo for future neuroprosthetics, devices, or cell and ECM delivery.

Neonatal encephalopathy plasma metabolites are associated with neurodevelopmental outcomes.

BACKGROUND: To investigate mechanisms of injury and recovery in neonatal encephalopathy (NE), we performed targeted metabolomic analysis of plasma using liquid chromatography with tandem mass spectrometry (LC/MS/MS) from healthy term neonates or neonates with NE. METHODS: Plasma samples from the NE (n = 45, day of life 0-1) or healthy neonatal (n = 30, ≥36 weeks gestation) cohorts had LC/MS/MS metabolomic profiling with a 193-plex targeted metabolite assay covering >366 metabolic pathways. Metabolite levels were compared to 2-year neurodevelopmental outcomes measured by the Bayley Scales of Infant and Toddler Development III (Bayley-III). RESULTS: Out of 193 metabolites, 57 met the pre-defined quality control criteria for analysis. Significant (after false discovery rate correction) KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways included aminoacyl-tRNA biosynthesis, arginine biosynthesis, and metabolism of multiple amino acids. Significant disease pathways included seizures. In regression models, histidine and C6 sugar amine were significantly associated with cognitive, motor, and language and betaine with cognitive and motor Bayley-III composite scores. The addition of histidine, C6 sugar amine, and betaine to a Sarnat score-based clinical regression model significantly improved model performance (Akaike information criterion and adjusted r2) for Bayley-III cognitive, motor, and language scores. CONCLUSIONS: Plasma metabolites may help to predict neurological outcomes in neonatal brain injury and enhance current clinical predictors. IMPACT: Plasma metabolites may help to predict neurological outcomes in NE and supplement current clinical predictors. Current metabolomics research is limited in terms of clinical application and association with long-term outcomes. Our study presents novel associations of plasma metabolites from the first 24 h of life and 2-year neurodevelopmental outcomes for infants with NE. Our metabolomics discovery provides insight into possible disease mechanisms and methods to rescue and/or supplement metabolic pathways involved in NE. Our metabolomics discovery of metabolic pathway supplementations and/or rescue mechanisms may serve as adjunctive therapies for NE.

Multi-organ dysfunction scoring in neonatal encephalopathy (MODE Score) and neurodevelopmental outcomes.

AIM: Neonatal encephalopathy (NE) is associated with an increased risk of multi-organ injury. The lack of standardised definitions for multi-organ dysfunction in NE hinders accurate quantification of these complications. METHODS: A simple multi-organ dysfunction in neonatal encephalopathy scoring (MODE) system was created to include the cardiovascular, respiratory, gastrointestinal, haematological and neurological systems with a maximum score of 15. The MODE score was then compared with the grade of NE, Bayley Scales of Infant Development (Bayley-III) at 2 years of age and mortality. The Bayley score was used as it gave an objective score making it easier to compare the MODE score. Bayley score of <90 and/or abnormal MRI as an adverse outcome. RESULTS: Infants with perinatal asphyxia (PA:n = 85) were prospectively enrolled (PA only n = 9; NE I = 23; NE II = 42; NE III = 11). Infants with higher MODE scores were significantly more likely to have moderate/severe NE (NE II/III: median scores (IQR) 7(5-10) versus mild NE 2 (1-3); p-value < 0.001) The MODE score was highly predictive of mortality (AUC 0.96, p-value = 0.002). Infants who had an abnormal neurological examination at discharge or abnormal Bayley-III scores had significantly higher MODE scores (p-value = 0.001). CONCLUSION: Quantifying multi-organ injury is important to plan optimal early management and long-term follow-up. Additional use of clinical biomarkers may be useful as surrogate endpoints in future clinical trials and link to multi-organ longer-term developmental follow-up.

Newly regenerated axons via scaffolds promote sub-lesional reorganization and motor recovery with epidural electrical stimulation.

Here, we report the effect of newly regenerated axons via scaffolds on reorganization of spinal circuitry and restoration of motor functions with epidural electrical stimulation (EES). Motor recovery was evaluated for 7 weeks after spinal transection and following implantation with scaffolds seeded with neurotrophin producing Schwann cell and with rapamycin microspheres. Combined treatment with scaffolds and EES-enabled stepping led to functional improvement compared to groups with scaffold or EES, although, the number of axons across scaffolds was not different between groups. Re-transection through the scaffold at week 6 reduced EES-enabled stepping, still demonstrating better performance compared to the other groups. Greater synaptic reorganization in the presence of regenerated axons was found in group with combined therapy. These findings suggest that newly regenerated axons through cell-containing scaffolds with EES-enabled motor training reorganize the sub-lesional circuitry improving motor recovery, demonstrating that neuroregenerative and neuromodulatory therapies cumulatively enhancing motor function after complete SCI.

Altered Cytokine Endotoxin Responses in Neonatal Encephalopathy Predict MRI Outcomes.

Background: Neonatal encephalopathy (NE) is associated with adverse neurodevelopmental outcome and is linked with systemic inflammation. Pro-inflammatory and anti-inflammatory cytokines are known to play a role in the pathology of NE by activating innate immune cells. Methods: Eighty-seven infants were enrolled including 53 infants with NE of whom 52 received therapeutic hypothermia (TH) and 34 term infant healthy controls (TC). Whole blood sampling was performed in the first 4 days of life, and a 14-spot ELISA Multiplex Cytokine Array was carried out on baseline samples or after stimulation with lipopolysaccharide (LPS) as an additional inflammatory stimulus. The cytokine medians were examined for differences between infants with NE and healthy TC; and then short-term outcomes of Sarnat stage, seizures, and MRI brain were examined within the NE group. The potential of LPS stimulation to predict abnormal MRI was explored using receiver operating characteristic (ROC) curves. Results: At baseline, infants with NE had significantly higher levels of erythropoietin (Epo), interleukin (IL)-6, and IL-1ra and significantly lower vascular endothelial growth factor (VEGF) than had controls. All cytokines were increased after LPS stimulation in infants with NE with an excessive Epo and IL-1ra response than in controls. Infants with NE had lower IL-8, IL-2, IL-6, tumor necrosis factor (TNF)-α, granulocyte-macrophage colony-stimulating factor (GM-CSF), VEGF, and interferon (IFN)-γ than controls had following LPS. GM-CSF and IFN-γ, IL-1ß, IL-1ra, and VEGF were higher on days 1-2 in NE infants with abnormal neuroimaging. GM-CSF, IFN-γ, and TNF-α levels with LPS stimulation were different upon stimulation between normal and abnormal neuroimaging. TNF-α is the only strong cytokine predictor both pre- and post-LPS stimulation of abnormal brain imaging. Conclusions: Altered cytokine responses are found in infants with NE vs. controls, and more significant differences are unmasked by the additional stimulus of LPS, which potentially improves the predictive power of these cytokines for the detection of abnormal MRIs. Infants with NE undergoing TH demonstrate both trained immunity and tolerance, and understanding these responses will facilitate adjunctive immunomodulatory treatments.

Cytokine dysregulation in children with cerebral palsy.

AIM: To examine pro- and anti-inflammatory cytokines in children with cerebral palsy (CP) at baseline and in response to endotoxin (lipopolysaccharide), and correlate outcomes compared with age-matched comparisons, to evaluate their ability to mount an immune response. METHOD: Serum cytokines were assessed in 12 children (eight males, four females; mean age 10y 1mo [SD 1y 8mo], 6-16y) with CP against 12 age-matched comparisons (eight males, four females; mean age 9y 1mo [SD 1y 1mo]). Pro- and anti-inflammatory cytokines (interleukin-1ß, interleukin-2, interleukin-6, interleukin-8, interleukin-10, interleukin-18, tumour necrosis factor [TNF]-α, TNF-ß, interferon-γ, granulocyte-macrophage colony-stimulating factor [GM-CSF], vascular endothelial growth factor [VEGF], erythropoietin, and interleukin-1 receptor antagonist) were measured at baseline and in response to in vitro simulation with lipopolysaccharide by multiplex enzyme-linked immunosorbent assay. RESULTS: Significantly higher erythropoietin was found at baseline in children with CP compared with the comparison group. There was a strong response to lipopolysaccharide for interleukin-8, VEGF, TNF-α, and GM-CSF in both children with CP and the comparison group; however, there was significant lipopolysaccharide hyporesponsiveness in children with CP compared with the comparison group for interleukin-1α, interleukin-1ß, interleukin-2, and interleukin-6. INTERPRETATION: Altered cytokine responses in children with CP compared with the comparison group demonstrate an altered inflammatory state that may contribute to ongoing sequelae and could be a target for therapy. WHAT THIS PAPER ADDS: Altered inflammatory responses persist in children with cerebral palsy (CP). Erythropoietin is elevated in children with CP compared with the comparison group. Children with CP have reduced interleukin-1α, interleukin-1ß, interleukin-2, and interleukin-6 inflammatory responses to lipopolysaccharide.

Plasma and Cerebrospinal Fluid Candidate Biomarkers of Neonatal Encephalopathy Severity and Neurodevelopmental Outcomes.

OBJECTIVES: To identify candidate biomarkers in both plasma and cerebrospinal fluid (CSF) that are associated with neonatal encephalopathy severity measured by encephalopathy grade, seizures, brain injury by magnetic resonance imaging (MRI), and neurodevelopmental outcomes at 15-30 months. STUDY DESIGN: A retrospective cohort study of plasma (N = 155, day of life 0-1) and CSF (n = 30, day of life 0-7) from neonates with neonatal encephalopathy and healthy neonates born at term (N = 30, ≥36 weeks of gestation) was conducted. We measured central nervous system necrosis (glial fibrillary acidic protein [GFAP], neurogranin [NRGN], tau), inflammatory (interleukin [IL]-6, IL-8, IL-10), and trophic (brain-derived neurotrophic factor [BDNF], vascular endothelial growth factor) proteins. Clinical outcomes were Sarnat scores of encephalopathy, seizures, MRI scores, and Bayley Scales of Infant and Toddler Development III at 15-30 months. RESULTS: Plasma NRGN, tau, IL-6, IL-8, and IL-10 were greater, whereas BDNF and vascular endothelial growth factor were lower in patients with neonatal encephalopathy vs controls. In plasma, tau, GFAP, and NRGN were directly and BDNF inversely associated with encephalopathy grade. IL-6 was inversely related to seizures. Tau was directly related to MRI abnormalities. Tau was inversely associated with Bayley Scales of Infant and Toddler Development III cognitive and motor outcomes. In CSF, NRGN was inversely associated with cognitive, motor, and language measures. GFAP, IL-6, and IL-10 were inversely related to cognitive and motor outcomes. IL-8 was inversely related to motor outcomes. CSF candidate biomarkers showed no significant relationships with encephalopathy grade, seizures, or MRI abnormalities. CONCLUSIONS: Plasma candidate biomarkers predicted encephalopathy severity, seizures, MRI abnormalities, and neurodevelopmental outcomes at 15-30 months.

Cytokine dysregulation persists in childhood post Neonatal Encephalopathy.

BACKGROUND: Cytokines are possible mediators of neuroinflammation and associated with adverse outcome in neonatal encephalopathy (NE). Our aim was to explore cytokine response in children with Neonatal Encephalopathy (NE) at school age compared to age-matched controls. METHOD: Follow up at school age, children who had NE and age-matched controls were assessed for their cytokine responses and neurodevelopment outcome. Pro- and anti-inflammatory cytokines in the serum, [Interleukin (IL)-1α, IL-1ß, IL-2, IL-6, IL-8, IL-18, Tumor necrosis factor (TNF)-α, TNF ß, Interferon (IFN)-γ, granulocyte-macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), erythropoietin (EPO), IL-10 & IL-1RA] were measured at baseline and in response to in vitro stimulation with lipopolysaccharide (LPS: endotoxin). RESULTS: GM-CSF, TNF-ß, IL-2 IL-6 and IL-8 were significantly elevated at school age following NE (n = 40) compared to controls (n = 37). A rise in GM-CSF, IL-8, TNF-α, IL-1ß, & IL-6 were seen in NE group following LPS stimulation. Relative LPS hypo-responsiveness was also noted in children with severe NE with IL-10, VEGF, EPO and TNF-ß. Elevated TNF-ß was associated with low gross motor scores on assessment at school age. CONCLUSION: School-age children post-NE had significantly altered cytokine responses to endotoxin compared to controls. TNF-ß was associated with adverse developmental outcomes. This suggests the inflammatory process may persist into childhood and a longer therapeutic window may be available for neuroprotection therapies.

Neonatal Encephalopathy Is Associated With Altered IL-8 and GM-CSF Which Correlates With Outcomes.

Aim: To investigate the relationship between cytokines associated with innate immune cell activation and brain injury and outcome in infants with NE compared to neonatal controls. Methods: Serum and CSF biomarkers associated with activated neutrophils and monocytes [Interleukin-8 (IL-8) and Granulocyte-Macrophage-Colony-Stimulating-Factor (GM-CSF)] were serially measured using duplex immunoassays on days 1, 3 and 7 in term newborns with NE and controls. Results were compared to grade of encephalopathy, seizures, MRI brain imaging, mortality and Bayley Score of Infant and Toddler Development (Bayley-III) at 2 years of age. Results: Ninety-four infants had serum samples collected with 34 CSF samples. NE Grade II/III was significantly associated with elevated on day 2 serum IL-8. Mortality was best predicted by elevated day 1 IL-8. GM-CSF was initially elevated on day 1 and abnormal MRI imaging was associated with decreased day 2 GM-CSF. Elevated GM-CSF at day of life 6-7 correlated negatively with composite cognitive, language and motor Bayley-III scores at 2 years. Conclusion: Moderate or severe NE and mortality was associated with elevated IL-8. Day 2 GM-CSF could predict abnormal MRI results in NE and Bayley-III. Therefore, these cytokines are altered in NE and may predict early outcomes and further implicate inflammatory processes in NE.

Pediatric Intensive Care: Immunomodulation With Activated Protein C ex vivo.

Objective: Sepsis is major cause of morbidity and mortality in the Pediatric Intensive Care Unit (PICU). PICU patients may develop transient immune deficiency during sepsis. Activated Protein C (APC) has significant anti-inflammatory and cytoprotective effects. Clinical trials of APC in adult sepsis initially showed improved outcome but recent trials showed no benefit in adults or children. We aimed to assess the effects of APC treatment on innate immune responses in children. Design and Subjects: We compared neutrophil and monocyte responses to lipopolysaccharide (LPS) with and without APC treatment in PICU patients at the time of evaluation for sepsis compared with healthy adults and age-matched pediatric controls. We used flow cytometry to examine cell activation (CD11b expression), function [intracellular reactive oxygen intermediate (ROI) release] and LPS recognition [Toll like Receptor 4 (TLR4) expression]. Results: PICU patients had significantly decreased protein c levels and LPS responses compared with adult and pediatric controls for all parameters. APC reduced LPS-induced neutrophil PICU TLR4 and adult ROI (p < 0.05). PICU non-survivors had increased LPS induced neutrophil and monocyte ROI production vs. survivors which was significantly reduced by APC. Conclusion: PICU patients demonstrate significantly reduced endotoxin reactivity which may predispose them to sepsis and alter effective antibacterial responses. APC reduces LPS-induced ROI production in adults and may have a role in treating severely compromised PICU patients especially given that newer APC forms are associated with decreased bleeding risk and enhanced anti-inflammatory effects.

Neonatal Encephalopathy: Need for Recognition of Multiple Etiologies for Optimal Management.

Neonatal encephalopathy (NE) is associated with high mortality and morbidity. Factors predisposing to NE can be antenatal, perinatal, or a combination of both. Antenatal maternal factors, familial factors, genetic predisposition, hypoxic ischemic encephalopathy, infections, placental abnormalities, thrombophilia, coagulation defects, and metabolic disorders all have been implicated in the pathogenesis of NE. At present, therapeutic hypothermia is the only treatment available, regardless of etiology. Recognizing the etiology of NE involved can also guide investigations such as metabolic and sepsis workups to ensure optimal management. Understanding the etiology of NE may allow the development of targeted adjunctive therapies related to the underlying mechanism and develop preventative strategies.